TECHNICAL FIELD

[0003] The present invention relates to a heat exchanger, such as a condenser or an evaporator, for use in a refrigeration cycle for an automobile air conditioner, a household air conditioner, a refrigerator or a cooler for electrical/electric equipments, especially for use in a refrigeration cycle using CO₂. It also relates to a header tank for such heat exchangers and methods for manufacturing them.

BACKGROUND ART

[0004] As a refrigerant for air conditioning apparatuses, Freon family refrigerant such as HCFC (hydro chlorofluorocarbon) and HFC (hydro fluorocarbon) is used widely. However, such Freon family refrigerant is ozone depleting substance and greenhouse substance (heat-trapping substance). Accordingly, their discharge into the atmospheric air is severely limited, and the alternatives of Freon family refrigerant, or the so-called defreonization, has been developing.

[0005] As one of the defreonizations, a refrigeration cycle which uses carbon dioxide (CO₂) as refrigerant has been proposed. CO₂ is one of natural refrigerants found in nature, and hardly affects the global environment as compared with Freon.

[0006] However, in cases where CO₂ is used as refrigerant in a refrigeration cycle, the refrigerant working pressure at a higher pressure side becomes high about 10 times as compared with Freon family refrigerant since the thermodynamic property peculiar to CO₂ causes a supercritical cycle. Accordingly, in cases where a structure of a refrigeration cycle apparatus such as a heat exchanger using conventional Freon family refrigerant is applied to a structure of a refrigeration cycle apparatus using CO₂ as refrigerant, it is required to improve the pressure resistance by, for example, increasing the wall thickness of various parts constituting the apparatus. This causes increased weight of the apparatus, and therefore it is difficult to achieve the practical use of such apparatus.

[0007] Under such a technical background, a high pressure resistance heat exchanger using CO₂ refrigerant is known (e.g., Japanese Unexamined Laid-open Patent Publication No. JP 2000-81294 A). In this heat exchanger, the header tank includes a header plate having a number of tube connection apertures into which end portions of heat exchanging tubes are connected and a plate cover covering one side of the header plate.

[0008] However, in the aforementioned conventional heat exchanger using CO₂ refrigerant, since the peripheral wall of the header tank is constituted by two members, the header plate and the plate cover, enough joining strength therebetween cannot be obtained. Therefore, there has been difficult to secure predetermined pressure resistance. If the cross-sectional area of the refrigerant passage in the header tank is increased in order to reduce the flow resistance, the joining area between the header plate and the cover plate decreases, resulting in decreased joining strength, which in turn further deteriorates the pressure resistance.

[0009] An object of the present invention is to solve the aforementioned problems of the conventional technique, and to provide a heat exchanger having small refrigerant flow resistance and enough pressure resistance, especially a heat exchanger preferably applied to a refrigeration cycle using CO₂ refrigerant. Another object of the present invention is to provide a header tank for such a heat exchanger, a method for manufacturing the heat exchanger and a method for manufacturing the header tank.

[0010] Other objects of the present invention will become apparent from the following explanations.

DISCLOSURE OF INVENTION

[0011] In order to attain the aforementioned objects, according to the first aspect of the present invention, a heat exchanger, comprises:

[0012] a pair of header tanks; and

[0013] a plurality of heat exchanging tubes disposed between the pair of header tanks in parallel in a longitudinal direction of the header tanks with opposite ends thereof connected to the pair of header tanks in fluid communication,

[0014] wherein each of the pair of header tanks includes a header tank main body having a plate connecting surface located at a tube connecting side thereof and a cover plate secured to the plate connecting surface,

[0015] wherein the header tank main body is provided with a refrigerant passage continuously extending along a longitudinal direction of the header tank main body and a plurality of tube connecting apertures formed in the plate connecting surface at predetermined intervals in a longitudinal direction of the refrigerant passages and communicated with the refrigerant passage,

[0016] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures, and

[0017] wherein the plurality of heat exchanging tubes, the cover plate and the header tank main body are secured with each other in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication.

[0018] In this heat exchanger, approximately the entire peripheral wall of the header tank is formed by the header tank main body which can be formed integrally and the tube connecting side of the header tank main body is reinforced by the cover plate. Accordingly, enough strength against the inner pressure can be obtained, enabling an increased cross-sectional area of refrigerant passage, which in turn can decrease the flow resistance.

[0019] The heat exchanger according to the first aspect of the present invention can be preferably applied to a heat exchanger in which a plurality of heat exchanging tubes are arranged in plural rows in the front-and-rear direction and the refrigerant is U-turned in one of header tanks.

[0020] According to the 2^nd aspect of the present invention, a heat exchanger, comprises:

[0021] a pair of header tanks; and

[0022] a plurality of heat exchanging tubes disposed between the pair of header tanks in parallel in a longitudinal direction of the header tanks with opposite ends thereof connected to the pair of header tanks in fluid communication, the plurality of heat exchanging tubes being arranged in plural rows in a widthwise direction of the header tank,

[0023] wherein each of the pair of header tanks includes a header tank main body having a plate connecting surface located at a tube connecting side thereof and a cover plate secured to the plate connecting surface,

[0024] wherein the header tank main body is provided with a refrigerant inlet passage continuously extending along a longitudinal direction of the header tank main body at a front side of the header tank main body, a refrigerant outlet passage continuously extending along a longitudinal direction of the header tank main body at a rear side of the header tank main body, and a plurality of tube connecting apertures formed in front and rear sides of the plate connecting surface at predetermined intervals in a longitudinal direction of the refrigerant inlet passages and the refrigerant outlet passages and communicated with the refrigerant inlet passages and the refrigerant outlet passages respectively,

[0025] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures,

[0026] wherein one of the pair of header tanks is provided with a communication aperture communicating with the refrigerant inlet passage and the refrigerant outlet passage, and

[0027] wherein each of the plurality of heat exchanging tubes, the cover plate and the header tank main body are secured with each other in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication.

[0028] In this heat exchanger, like the aforementioned heat exchanger, enough strength against the inner pressure can be secured, and the refrigerant flow resistance can also be decreased.

[0029] Furthermore, since the refrigerant passing through the front side heat exchanging tubes is introduced into the rear side heat exchanging tubes via the communication aperture to thereby U-turn the refrigerant flow, the heat exchanging of the refrigerant can be further enhanced.

[0030] In the 2^nd aspect of the present invention, it is preferable that the refrigerant inlet passage and the refrigerant outlet passage formed in the header tank main body include plural passages arranged in parallel, respectively.

[0031] In this case, the number of partitioning walls partitioning the refrigerant passages can be increased and the most of them function as reinforcing walls, which further enhances the strength against the inner pressure.

[0032] In the 2^nd aspect of the present invention, it is preferable that the header tank main body has a cut portion formed from an outside surface of an end portion of the header tank main body and extending to the refrigeration inlet passage and the refrigeration outlet passage, and wherein end portions of the refrigerant inlet passage and the refrigerant outlet passage are closed by a blocking plate inserted in and secured to the cut portion.

[0033] In this case, the ends of the refrigerant passages can be assuredly closed by a simple work such that a cut portion is formed in the end portion of the header tank main body and the blocking plate is inserted therein.

[0034] According to the 3^rd aspect of the present invention, a heat exchanger, comprises:

[0035] a pair of header tanks; and

[0036] a plurality of heat exchanging tubes disposed between the pair of header tanks in parallel in a longitudinal direction of the header tanks with opposite ends thereof connected to the pair of header tanks in fluid communication,

[0037] wherein each of the pair of header tanks includes a header tank main body having a plate connecting surface located at a tube connecting side thereof and a cover plate secured to the plate connecting surface,

[0038] wherein the header tank main body is provided with a refrigerant passage continuously extending along a longitudinal direction of the header tank main body and a plurality of tube connecting apertures formed in the plate connecting surface at predetermined intervals in a longitudinal direction of the refrigerant passages and communicated with the refrigerant passage,

[0039] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures,

[0040] wherein the refrigerant passage in the header tank main body is provided with engaging stepped portions each engaging an end portion of each of the plurality of heat exchanging tubes, and

[0041] wherein the plurality of heat exchanging tubes, the cover plate and the header tank main body are secured with each other in a state in which the end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging stepped portion.

[0042] In this heat exchanger, like the heat exchanger according to the 1^st aspect of the present invention, enough strength against the inner pressure can be secured, and the refrigerant flow resistance can be decreased.

[0043] Furthermore, since engaging stepped portions each engaging an end portion of each of the plurality of heat exchanging tubes are formed at portions corresponding to the tube connecting apertures of the header tank main body, when inserting the heat exchanging tube into the connecting aperture of the header tank main body, the end portion of the heat exchanging tube is engaged with the engaging stepped portion. Thus, the heat exchanging tube can be positioned in the insertion direction thereof, which enables an easy tube connecting work.

[0044] According to the 4^th aspect of the present invention, a heat exchanger, comprises:

[0045] a pair of header tanks; and

[0046] a plurality of heat exchanging tubes disposed between the pair of header tanks in parallel in a longitudinal direction of the header tanks with opposite ends thereof connected to the pair of header tanks in fluid communication,

[0047] wherein each of the pair of header tanks includes a header tank main body having a plate connecting surface located at a tube connecting side thereof and a cover plate secured to the plate connecting surface,

[0048] wherein the header tank main body is provided with a plurality of refrigerant passages continuously extending along a longitudinal direction of the header tank main body and arranged in a widthwise direction of the header tank main body, and a plurality of tube connecting apertures formed in the plate connecting surface so as to bride the plurality of refrigerant passages at predetermined intervals in a longitudinal direction of the refrigerant passage and communicated with the plurality of refrigerant passages,

[0049] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures,

[0050] wherein a partitioning wall partitioning the plurality of refrigerant passages in the header tank main body is provided with engaging dented stepped portions corresponding to the plurality of tube connecting apertures and engaged with end portions of the plurality of heat exchanging tubes, and

[0051] wherein the plurality of heat exchanging tubes, the cover plate and the header tank main body are secured with each other in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging dented stepped portion.

[0052] In this heat exchanger, like the heat exchanger according to the 3^rd aspect of the present invention, enough strength against the inner pressure can be secured, and the refrigerant flow resistance can be decreased. Furthermore, when inserting the heat exchanging tube into the connecting aperture of the header tank main body, the end portion of the heat exchanging tube is engaged with the engaging stepped portion. Thus, the heat exchanging tube can be positioned in the insertion direction thereof.

[0053] Like the 4^th aspect of the present invention, in cases where the refrigerant passages are arranged in parallel, it is possible to form an engaging dented stepped portion as an engaging stepped portion at the partitioning wall partitioning the passages.

[0054] In this 4^th aspect of the present invention, it is preferable that a communication groove communicating with end openings of tube apertures of the plurality of heat exchanging tubes and the plurality of refrigerant passages is formed at a bottom surface of the engaging dented stepped portion.

[0055] That is, in cases where the end face of the heat exchanging tube is engaged with the bottom surface of the engaging dented stepped portion, some of the end openings of the tube apertures may be blocked by the bottom surface of the engaging dented stepped portion. However, when the aforementioned communication agroove is formed, all of the tube apertures can be communicated with the refrigerant passage, which can prevent the deterioration of the flow amount of refrigerant.

[0056] According to the 5^th aspect of the present invention, a heat exchanger, comprises:

[0057] a pair of header tanks; and

[0058] a plurality of heat exchanging tubes disposed between the pair of header tanks in parallel in a longitudinal direction of the header tank with opposite ends of each of the plurality of heat exchanging tubes connected to the pair of header tanks in fluid communication, the plurality of heat exchanging tubes being arranged in plural rows in a widthwise direction of the header tank,

[0059] wherein each of the pair of header tanks includes a header tank main body having a plate connecting surface located at a tube connecting side thereof and a cover plate secured to the plate connecting surface,

[0060] wherein the header tank main body is provided with a plurality of refrigerant inlet passage continuously extending along a longitudinal direction of the header tank main body at a front side of the header tank main body and disposed in parallel in a widthwise direction of the header tank main body, a plurality of refrigerant outlet passage continuously extending along a longitudinal direction of the header tank main body at a rear side of the header tank main body and disposed in parallel in a widthwise direction of the header tank main body, a plurality of tube connecting apertures formed in a front side of the plate connecting surface so as to bride the plurality of refrigerant inlet passages at predetermined intervals in a longitudinal direction of the refrigerant inlet passage and communicated with the plurality of refrigerant inlet passages, and a plurality of tube connecting apertures formed in a rear side of the plate connecting surface so as to bride the plurality of refrigerant outlet passages at predetermined intervals in a longitudinal direction of the refrigerant outlet passage and communicated with the plurality of refrigerant outlet passages,

[0061] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures,

[0062] wherein one of the pair of header tanks is provided with a communication aperture communicating with the plurality of refrigerant inlet passages and the plurality of refrigerant outlet passages,

[0063] wherein a partitioning wall partitioning the plurality of refrigerant inlet passages and a partitioning wall partitioning the plurality of refrigerant outlet passages in the header tank main body are provided with engaging dented stepped portions corresponding to the plurality of tube connecting apertures respectively, and

[0064] wherein the plurality of heat exchanging tubes, the cover plate and the header tank main body are secured with each other in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging dented stepped portion.

[0065] In this heat exchanger according to the 5^th aspect of the present invention, like the 4^th aspect of the present invention, enough strength against the inner pressure can be secured, and the refrigerant flow resistance can be decreased. Furthermore, when inserting the heat exchanging tube into the connecting aperture of the header tank main body, the heat exchanging tube can be positioned in the insertion direction thereof.

[0066] In the 5^th aspect of the present invention, it is preferable that a communication groove communicating with end openings of tube apertures of the plurality of heat exchanging tubes and the plurality of refrigerant inlet passages and a communication groove communicating with end openings of tube apertures of the plurality of heat exchanging tubes and the plurality of refrigerant outlet passages are formed at a bottom surface of the engaging dented stepped portion respectively.

[0067] In this case, all of the tube apertures can be communicated with the refrigerant inlet passages and the refrigerant outlet passages, which secures an sufficient refrigerant flow amount.

[0068] As the configuration of the communication aperture, the following can be exemplified.

[0069] In the 5^th aspect of the present invention, the communication groove may be formed into a generally V-shape, and the communication groove may be formed into a generally U-shape.

[0070] In the heat exchanger according to the 1^st to 5^th aspect of the present invention, since the heat exchanger has enough strength against the inner pressure, the heat exchanger can be preferably applied to a heat exchanger for use in a vapor compression type refrigeration cycle using CO₂ refrigerant.

[0071] That is, in the heat exchanger according to the 1^st to 5^th aspect of the present invention, it is preferable that carbon dioxide refrigerant (CO₂ refrigerant) is used as the refrigerant.

[0072] The 6^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger according to the 1^st aspect of the present invention.

[0073] According to the 6^th aspect of the present invention, a method for manufacturing a heat exchanger including a pair of header tanks and a plurality of heat exchanging tubes disposed between the pair of header tanks and arranged in parallel in a longitudinal direction of the header tank with opposite ends thereof connected to the pair of header tanks in fluid communication, the method, comprises:

[0074] preparing an intermediate having a flat plate connecting surface at a tube connecting side thereof and a refrigerant passage extending in a longitudinal direction of the intermediate;

[0075] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the refrigerant passage in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate;

[0076] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0077] integrally joining the header tank main body, the cover plate and the plurality of heat exchanging tubes in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication.

[0078] The 7^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger according to the 2^nd aspect of the present invention.

[0079] According to the 7^th aspect of the present invention, a method for manufacturing a heat exchanger including a pair of header tanks and a plurality of heat exchanging tubes disposed between the pair of header tanks and arranged in parallel in a longitudinal direction of the header tank with opposite ends thereof connected to the pair of header tanks in fluid communication, the plurality of heat exchanging tubes being arranged in plural rows in a widthwise direction of the header tank, the method, comprises:

[0080] preparing an intermediate having a flat plate connecting surface at a tube connecting side, a refrigerant inlet passage extending in a longitudinal direction of the intermediate at a front side of the intermediate, and a refrigerant outlet passage extending in a longitudinal direction of the intermediate at a rear side of the intermediate;

[0081] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the refrigerant inlet passage in a front side of the plate connecting surface of the intermediate at predetermined intervals, in a longitudinal direction of the intermediate and a plurality of tube connecting apertures communicating with the refrigerant outlet passage in a rear side of the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate;

[0082] forming a communication aperture communicating with the refrigerant inlet passage and the refrigerant outlet passage in the plate connecting surface of the header tank main body corresponding to one of the pair of header tanks;

[0083] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0084] integrally joining the header tank main body, the cover plate and the plurality of heat exchanging tubes in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication.

[0085] In the 7^th aspect of the present invention, it is preferable that the refrigerant inlet passage and the refrigerant outlet passage are formed to have plural rows arranged in parallel, respectively.

[0086] In this case, the number of partitioning walls partitioning the refrigerant passages can be increased, which further enhances the strength against the inner pressure.

[0087] In the 7^th aspect of the present invention, it is preferable that the intermediate having the refrigerant inlet passage and the refrigerant outlet passage is formed by extrusion molding or drawing molding.

[0088] In this case, the intermediate can be formed easily, which in turn can manufacture the heat exchanger efficiently. Furthermore, the header tank main body can be formed as an integral formed member having high strength, which can further enhance the strength against the inner pressure.

[0089] The 7^th aspect of the present invention, it is preferable that the plate connecting surface is formed by milling.

[0090] In this case, the plate connecting surface can be formed into a flat and smooth surface, resulting in strong joining of the cover plate, which in turn can further enhance the strength against the inner pressure.

[0091] In the 7^th aspect of the present invention, it is preferable to employ the tube connecting apertures formed by cutting, and the communication apertures formed by cutting.

[0092] In this case, the tube connecting apertures and the communication apertures can be formed in high accuracy.

[0093] In the 7^th aspect of the present invention, it is preferable that the tube connecting apertures and the communication apertures are formed simultaneously.

[0094] In this case, the simultaneous forming of these apertures can decreases the number of working processes, resulting in further enhanced productivity.

[0095] The 8^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger according to the 3^rd aspect of the present invention.

[0096] According to the 8^th aspect of the present invention, a method for manufacturing a heat exchanger including a pair of header tanks and a plurality of heat exchanging tubes disposed between the pair of header tanks and arranged in parallel in a longitudinal direction of the header tank with opposite ends thereof connected to the pair of header tanks in fluid communication, the method, comprises:

[0097] preparing an intermediate having a flat plate connecting surface at a tube connecting side thereof and a refrigerant passage extending in a longitudinal direction of the intermediate;

[0098] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the refrigerant passage in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate and engaging stepped portions each capable of engaging with an end portion of the heat exchanging tube at a portion corresponding to each of the plurality of tube connecting apertures;

[0099] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0100] integrally joining the header tank main body, the cover plate and the plurality of heat exchanging tubes in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging stepped portion.

[0101] The 9^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger according to the 4^th aspect of the present invention.

[0102] According to the 9^th aspect of the present invention, a method for manufacturing a heat exchanger including a pair of header tanks and a plurality of heat exchanging tubes disposed between the pair of header tanks and arranged in parallel in a longitudinal direction of the header tank with opposite ends thereof connected to the pair of header tanks in fluid communication, the method, comprises:

[0103] preparing an intermediate having a flat plate connecting surface at a tube connecting side thereof and a plurality of refrigerant passages extending in a longitudinal direction of the intermediate and disposed in a widthwise direction of the intermediate;

[0104] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the plurality of refrigerant passages so as to bridge the plurality of refrigerant passages in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate and engaging dented stepped portions each capable of engaging with an end portion of the heat exchanging tube at a partitioning walls partitioning the plurality of refrigerant passages portion corresponding to each of the plurality of tube connecting apertures;

[0105] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0106] integrally joining the header tank main body, the cover plate and the plurality of heat exchanging tubes in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging dented stepped portion.

[0107] In the 9^th aspect of the present invention, it is preferable that, at a step of obtaining the header tank main body, a communication groove communicating with end openings of tube apertures of the heat exchanging tube and the plurality of refrigerant passages is formed at a bottom surface of each of the engaging dented stepped portions.

[0108] In this case, in the similar manner as mentioned above, all of the tube apertures can be communicated with the refrigerant passage, resulting in enough refrigerant flow amount.

[0109] The 10^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger according to the 5^th aspect of the present invention.

[0110] According to the 10^th aspect of the present invention, a method for manufacturing a heat exchanger including a pair of header tanks and a plurality of heat exchanging tubes disposed between the pair of header tanks and arranged in parallel in a longitudinal direction of the header tank with opposite ends thereof connected to the pair of header tanks in fluid communication, the plurality of heat exchanging tubes being arranged in plural rows in a widthwise direction of the header tank, the method, comprises:

[0111] preparing an intermediate having a flat plate connecting surface at a tube connecting side thereof, refrigerant inlet passages extending in a longitudinal direction of the intermediate at a front side of the intermediate and arranged in a widthwise direction of the intermediate, and refrigerant outlet passages extending in a longitudinal direction of the intermediate at a rear side of the intermediate and arranged in a widthwise direction of the intermediate;

[0112] obtaining a header tank main body by forming a plurality of front side tube connecting apertures communicating with the plurality of refrigerant inlet passages so as to bridge the plurality of refrigerant inlet passages in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate, a plurality of rear side tube connecting apertures communicating with the plurality of refrigerant outlet passages so as to bridge the plurality of refrigerant outlet passages in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate, engaging dented stepped portions each capable of engaging with an end portion of the front side heat exchanging tube at partitioning walls partitioning the plurality of refrigerant inlet passages corresponding to each of the plurality of tube connecting apertures, and engaging dented stepped portions each capable of engaging with an end portion of the rear side heat exchanging tube at partitioning walls partitioning the plurality of refrigerant outlet passages corresponding to each of the plurality of tube connecting apertures;

[0113] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0114] integrally joining the header tank main body, the cover plate and the plurality of heat exchanging tubes in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging dented stepped portion.

[0115] In the 10^th aspect of the present invention, like the 5^th aspect of the present invention, it is preferable that, at a step of obtaining the header tank main body, a communication groove communicating with end openings of tube apertures of the heat exchanging tube and the plurality of refrigerant inlet passages and a communication groove communicating with end openings of tube apertures of the heat exchanging tube and the plurality of refrigerant outlet passages are formed at a bottom surface of each of the engaging dented stepped portions.

[0116] The 11^th aspect of the present invention specifies the header tank as a main component of the heat exchanger according to the 1^st aspect of the present invention.

[0117] According to the 11^th aspect of the present invention, a heat exchanger header tank for connecting end portions of a plurality of heat exchanging tubes disposed in parallel in fluid communication, the heat exchanger header tank, comprises:

[0118] a header tank main body having a plate connecting surface located at a tube connecting side thereof; and

[0119] a cover plate secured to the plate connecting surface,

[0120] wherein the header tank main body is provided with a refrigerant passage continuously extending along a longitudinal direction of the header tank main body and a plurality of tube connecting apertures formed in the plate connecting surface at predetermined intervals in a longitudinal direction of the refrigerant passages and communicated with the refrigerant passage, and

[0121] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures,

[0122] whereby each of the plurality of heat exchanging tubes and the cover plate are secured with each other in a state in which an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication.

[0123] The 12^th aspect of the present invention specifies the header tank as a main component of the heat exchanger according to the 2^nd aspect of the present invention.

[0124] According to the 12^th aspect of the present invention, a heat exchanger header tank for connecting end portions of a plurality of heat exchanging tubes disposed in parallel in fluid communication, the heat exchanger header tank, comprises:

[0125] a header tank main body having a plate connecting surface located at a tube connecting side thereof; and

[0126] a cover plate secured to the plate connecting surface,

[0127] wherein the header tank main body is provided with a refrigerant inlet passage continuously extending along a longitudinal direction of the header tank main body at a widthwise front side of the header tank main body, a refrigerant outlet passage continuously extending along a longitudinal direction of the header tank main body at a widthwise rear side of the header tank main body, and a plurality of tube connecting apertures formed in front and rear sides of the plate connecting surface at predetermined intervals in a longitudinal direction of the refrigerant inlet passages and the refrigerant outlet passages and communicated with the refrigerant inlet passages and the refrigerant outlet passages respectively, and

[0128] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures,

[0129] whereby an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication.

[0130] In the 12^th aspect of the present invention, like the 2^nd aspect of the present invention, it is preferable to employ the flowing structure.

[0131] That is, in the 12^th aspect of the present invention, 1) it is preferable that the refrigerant inlet passage and the refrigerant outlet passage formed in the header tank main body include plural passages arranged in parallel, respectively; 2) it is preferable that the header tank main body has a cut portion formed from an outside surface of an end portion of the header tank main body and extending to the refrigeration inlet passage and the refrigeration outlet passage, and wherein end portions of the refrigerant inlet passage and the refrigerant outlet passage are closed by a blocking plate inserted in and secured to the cut portion; 3) it is preferable that the header tank main body has a communication aperture communicating with the refrigerant inlet passage and the refrigerant outlet passage.

[0132] The 13^th aspect of the present invention specifies the header tank as a main component of the heat exchanger according to the 3rd aspect of the present invention.

[0133] According to the 13^th aspect of the present invention, a heat exchanger header tank for connecting end portions of a plurality of heat exchanging tubes disposed in parallel in fluid communication, the heat exchanger header tank, comprises:

[0134] a header tank main body having a plate connecting surface located at a tube connecting side thereof; and

[0135] a cover plate secured to the plate connecting surface,

[0136] wherein the header tank main body is provided with a refrigerant passage continuously extending along a longitudinal direction of the header tank main body and a plurality of tube connecting apertures formed in the plate connecting surface at predetermined intervals in a longitudinal direction of the refrigerant passage and communicated with the refrigerant passage,

[0137] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures, and

[0138] wherein the refrigerant passage in the header tank main body is provided with engaging stepped portions for engaging end portions of the plurality of heat exchanging tubes,

[0139] whereby the end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portions of the plurality of heat exchanging tubes engaged with the engaging stepped portions.

[0140] The 14^th aspect of the present invention specifies the header tank as a main component of the heat exchanger according to the 4^th aspect of the present invention.

[0141] According to the 14^th aspect of the present invention, a heat exchanger header tank for connecting end portions of a plurality of heat exchanging tubes disposed in parallel in fluid communication, the heat exchanger header tank, comprises:

[0142] a header tank main body having a plate connecting surface located at a tube connecting side thereof; and

[0143] a cover plate secured to the plate connecting surface,

[0144] wherein the header tank main body is provided with a plurality of refrigerant passages continuously extending along a longitudinal direction of the header tank main body and arranged in a widthwise direction of the header tank main body, and a plurality of tube connecting apertures formed in the plate connecting surface so as to bride the plurality of refrigerant passages at predetermined intervals in a longitudinal direction of the refrigerant passage and communicated with the plurality of refrigerant passages,

[0145] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures, and

[0146] wherein a partitioning wall partitioning the plurality of refrigerant passages in the header tank main body is provided with an engaging dented stepped portion corresponding to the tube connecting aperture and engaging with an end portion of each of the plurality of heat exchanging tubes,

[0147] whereby an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging dented stepped portion.

[0148] In the 14^th aspect of the present invention, like the 4^th aspect of the present invention, it is preferable that a communication groove communicating with end openings of tube apertures of the plurality of heat exchanging tubes and the plurality of refrigerant passages is formed at a bottom surface of the engaging dented stepped portion.

[0149] The 15^th aspect of the present invention specifies the header tank as a main component of the heat exchanger according to the 5^th aspect of the present invention.

[0150] According to the 15^th aspect of the present invention, a heat exchanger header tank for connecting end portions of a plurality of heat exchanging tubes disposed in parallel in fluid communication, the heat exchanger header tank, comprising:

[0151] a header tank main body having a plate connecting surface located at a tube connecting side; and

[0152] a cover plate secured to the plate connecting surface,

[0153] wherein the header tank main body is provided with a plurality of refrigerant inlet passages continuously extending along a longitudinal direction of the header tank main body at a front side of the header tank main body and disposed in parallel in a widthwise direction of the header tank main body, a plurality of refrigerant outlet passage continuously extending along a longitudinal direction of the header tank main body at a rear side of the header tank main body and disposed in parallel in a widthwise direction of the header tank main body, a plurality of tube connecting apertures formed in a front side of the plate connecting surface so as to bride the plurality of refrigerant inlet passages at predetermined intervals in a longitudinal direction of the refrigerant inlet passage and communicated with the plurality of refrigerant inlet passages, and a plurality of tube connecting apertures formed in a rear side of the plate connecting surface so as to bride the plurality of refrigerant outlet passages at predetermined intervals in a longitudinal direction of the refrigerant outlet passage and communicated with the plurality of refrigerant outlet passages,

[0154] wherein the cover plate is provided with a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures, and

[0155] wherein a partitioning wall partitioning the plurality of refrigerant inlet passages and a partitioning wall partitioning the plurality of refrigerant outlet passages in the header tank main body are provided with an engaging dented stepped portion corresponding to the tube connecting aperture respectively,

[0156] whereby an end portion of each of the plurality of heat exchanging tubes is inserted into a corresponding one of the plurality of tube insertion apertures formed in the cover plate disposed on the plate connecting surface and connected to a corresponding one of the plurality of tube connecting aperture of the header tank main body in a fluid communication with the end portion of each of the plurality of heat exchanging tubes engaged with the engaging dented stepped portion.

[0157] In the 15^th aspect of the present invention, like the 5th aspect of the present invention, it is preferable that a communication groove communicating with end openings of tube apertures of the plurality of heat exchanging tubes and the plurality of refrigerant inlet passages and a communication groove communicating with end openings of tube apertures of the plurality of heat exchanging tubes and the plurality of refrigerant outlet passages are formed at a bottom surface of the engaging dented stepped portion respectively.

[0158] The 16^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger header tank according to the 6^th aspect of the present invention.

[0159] According to the 16^th aspect of the present invention, a method for manufacturing a heat exchanger header tank for connecting a plurality of heat exchanging tubes arranged in parallel, the method, comprises:

[0160] preparing an intermediate having a flat plate connecting surface at a tube connecting side thereof and a refrigerant passage extending in a longitudinal direction of the intermediate;

[0161] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the refrigerant passage in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate;

[0162] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0163] joining the cover plate to the plate connecting surface of the header tank main body in a state in which the plurality of heat exchanging tubes are fitted in the plurality of tube insertion apertures.

[0164] The 17^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger header tank according to the 7^th aspect of the present invention.

[0165] According to the 17^th aspect of the present invention, a method for manufacturing a heat exchanger header tank for connecting a plurality of heat exchanging tubes arranged in parallel, the method, comprises:

[0166] preparing an intermediate having a flat plate connecting surface at a tube connecting side, a refrigerant inlet passage extending in a longitudinal direction of the intermediate at a front side of the intermediate, and a refrigerant outlet passage extending in a longitudinal direction of the intermediate at a rear side of the intermediate;

[0167] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the refrigerant inlet passage in a front side of the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate and a plurality of tube connecting apertures communicating with the refrigerant outlet passage in a rear side of the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate;

[0168] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0169] joining the cover plate to the plate connecting surface of the header tank main body in a state in which the plurality of heat exchanging tubes are fitted in the plurality of tube insertion apertures.

[0170] In the 17^th aspect of the present invention, it is preferable that the refrigerant inlet passage and the refrigerant outlet passage are formed to have plural rows arranged in parallel, respectively.

[0171] The 18^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger header tank according to the 8^th aspect of the present invention.

[0172] According to the 18^th aspect of the present invention, a method for manufacturing a heat exchanger header tank for connecting a plurality of heat exchanging tubes arranged in parallel, the method, comprises:

[0173] preparing an intermediate having a flat plate connecting surface at a tube connecting side and a refrigerant passage extending in a longitudinal direction of the;

[0174] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the refrigerant passage in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate and engaging stepped portions each capable of engaging with an end portion of the heat exchanging tube at a portion corresponding to each of the plurality of tube connecting apertures;

[0175] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0176] joining the cover plate to the plate connecting surface of the header tank main body in a state in which the plurality of heat exchanging tubes are fitted in the plurality of tube insertion apertures.

[0177] The 19^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger header tank according to the 9^th aspect of the present invention.

[0178] According to the 19^th aspect of the present invention, a method for manufacturing a heat exchanger header tank for connecting a plurality of heat exchanging tubes arranged in parallel, the method, comprises:

[0179] preparing an intermediate having a flat plate connecting surface at a tube connecting side and a plurality of refrigerant passages extending in a longitudinal direction of the intermediate and arranged in a widthwise direction of the intermediate;

[0180] obtaining a header tank main body by forming a plurality of tube connecting apertures communicating with the plurality of refrigerant passages so as to bridge the plurality of refrigerant passages in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate and engaging dented stepped portions each capable of engaging with an end portion of the heat exchanging tube at partitioning walls partitioning the plurality of refrigerant passages at a portion corresponding to each of the plurality of tube connecting apertures;

[0181] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0182] joining the cover plate to the plate connecting surface of the header tank main body in a state in which the plurality of heat exchanging tubes are fitted in the plurality of tube insertion apertures.

[0183] In the 19^th aspect of the present invention, like the 9^th aspect of the present invention, it is preferable that, at a step of obtaining the header tank main body, a communication groove communicating with end openings of tube apertures of the heat exchanging tube and the plurality of refrigerant passages is formed at a bottom surface of the engaging dented stepped portion.

[0184] The 20^th aspect of the present invention specifies one of manufacturing processes of the heat exchanger header tank according to the 10^th aspect of the present invention.

[0185] According to the 20^th aspect of the present invention, a method for manufacturing a heat exchanger header tank for connecting a plurality of heat exchanging tubes arranged in parallel, the method, comprises:

[0186] preparing an intermediate having a flat plate connecting surface at a tube connecting side, refrigerant inlet passages extending in a longitudinal direction of the intermediate at a front side of the intermediate and arranged in a widthwise direction of the intermediate, and refrigerant outlet passages extending in a longitudinal direction of the intermediate at a rear side of the intermediate and arranged in a widthwise direction of the intermediate;

[0187] obtaining a header tank main body by forming a plurality of front side tube connecting apertures communicating with the plurality of refrigerant inlet passages so as to bridge the plurality of refrigerant inlet passages in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate, a plurality of rear side tube connecting apertures communicating with the plurality of refrigerant outlet passages so as to bridge the plurality of refrigerant outlet passages in the plate connecting surface of the intermediate at predetermined intervals in a longitudinal direction of the intermediate, engaging dented stepped portions each capable of engaging with an end portion of the front side heat exchanging tube at partitioning walls partitioning the plurality of refrigerant inlet passages corresponding to each of the plurality of tube connecting apertures, and engaging dented stepped portions each capable of engaging with an end portion of the rear side heat exchanging tube at partitioning walls partitioning the plurality of refrigerant outlet passages corresponding to each of the plurality of tube connecting apertures;

[0188] preparing a cover plate to be fitted to the plate connecting surface, the cover plate having a plurality of tube insertion apertures corresponding to the plurality of tube connecting apertures; and

[0189] joining the cover plate to the plate connecting surface of the header tank main body in a state in which the plurality of heat exchanging tubes are fitted in the plurality of tube insertion apertures.

[0190] In the 20^th aspect of the present invention, like the 10^th aspect of the present invention, it is preferable that, at a step of obtaining the header tank main body, a communication groove communicating with end openings of tube apertures of the heat exchanging tube and the plurality of refrigerant inlet passages and a communication groove communicating with end openings of tube apertures of the heat exchanging tube and the plurality of refrigerant outlet passages are formed at a bottom surface of the engaging dented stepped portion.

[0191] The above and/or other aspects, features and/or advantages of various embodiments will be further appreciated in view of the following description in conjunction with the accompanying figures. Various embodiments can include and/or exclude different aspects, features and/or advantages where applicable. In addition, various embodiments can combine one or more aspect or feature of other embodiments where applicable. The descriptions of aspects, features and/or advantages of particular embodiments should not be construed as limiting other embodiments or the claims.