Claims:
What is claimed is
1. A reactor for an internal combustion engine including a block comprising:
2. The reactor as claimed in claim 1, wherein said second pipe means includes two pipes each defining the inlet passage for introducing the exhaust gas into said reaction chamber, said first pipe means defines the outlet passage for exhausting the exhaust gas from said reaction chamber, and said fixing means is arranged between said two pipes.
3. The reactor as claimed in claim 1, wherein: a sealing plate member has an opening corresponding to the outer periphery of said second pipe means and receives said second pipe means, said sealing plate member is positioned between said outer shell and said block of the engine for sealing and slidable movement in the direction normal to the axis of said second pipe means and at least one connection means between said second pipe means and said inner shell and between said second pipe means and said sealing plate member are sealable and slidable in the axial direction of said second pipe means.
4. The reactor as claimed in claim 1, wherein said first pipe means comprises a tube fixed to one end of said inner shell, an exhaust gas tube is fixed to a corresponding end of said outer shell and receives said tube to permit said tube to slide in the axial direction of said tube, and said reactor further comprises a pin fixed to the other end of said inner shell and a fulcrum shaft fixed to the other end of said outer shell receiving said pin to permit said pin to slide in the axial direction of said tube.
5. The reactor as claimed in claim 1, wherein said inner and outer shells are formed in section whose edges are welded together to form sealed units.
6. The reactor as claimed in claim 2, wherein said first pipe means comprises a tube fixed to one end of said inner shell and an exhaust gas tube fixed to a corresponding end of said outer shell and receiving said tube to permit said tube to slide in the axial direction of said tube, said reactor further comprises a pin fixed to the other end of said inner shell and a fulcrum shaft fixed to the other end of said outer shell receiving said pin to permit said pin to slide in the axial direction of said tube.
7. The reactor as claimed in claim 9, wherein: sealing plate members each have an opening corresponding to the outer periphery of each pipe and receive each pipe, means sealably and slidably position each sealing plate member in the direction normal to the axis of said pipes between said outer shell and said block of the engine and at least one connection means between each pipe and said inner shell and between each pipe and each sealing plate member are sealable and slidable in the axial direction of said pipe.
8. The reactor as claimed in claim 2, wherein said inner and outer shells are formed in section whose edges are welded together to form sealed units.
9. The reactor as claimed in claim 7, wherein said first pipe means comprises a tube fixed to one end of said inner shell and an exhaust gas tube fixed to a corresponding end of said outer shell and receiving said tube to permit said tube to slide in the axial direction of said tube, said reactor further comprises a pin fixed to the other end of said inner shell and a fulcrum shaft fixed to the other end of said outer shell receiving said pin to permit said pin to slide in the axial direction of said tube.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a reactor for purifying exhaust gas of an internal combustion engine which has an inner shell forming a reaction chamber and an outer shell surrounding the inner shell through an adiabatic space, and more particularly to means for holding the reaction chamber and the adiabatic space air-tight while absorbing the heat expansion of the inner shell by the heat of the exhaust gas itself and by the combustion heat generated in the reaction chamber and for eliminating the vibration and noise created by the inner shell.
2. Description of the Prior Art
Generally, it is well known that a reactor for effectively purifying the exhaust gas may preferably be of multi-layer spaced walls forming an adiabatic space or zone rather than a single-layer wall and that if an adiabatic insulator material fills the adiabatic space, it has increased effects. In such a reactor, the temperature of the reaction chamber of the reactor increases extremely due to the heat of the exhaust gas itself and the combustion heat produced in the reaction chamber of the reactor. Therefore, since the reaction chamber is surrounded by the adiabatic space or adiabatic material filling the space, the temperature difference between the inner and outer shells is extremely large with the result, that the difference of the heat expansion between the inner and outer shells is also extremely large.
If the inner shell experiencing large heat expansion is integrally connected to the outer shell which hardly experiences heat expansion or to a flange for attaching the reactor to the internal combustion engine body, the inner shell experiences large internal stress because the heat expansion of the inner shell is restricted. A crack may occur at the portion having a large stress concentration with the result that it adversely affects the durability of the reactor.
SUMMARY OF THE INVENTION
The present invention provides a reactor which purifies the exhaust gas of an internal combustion engine while eliminating the aforementioned disadvantages of the conventional reactor. Further, the reactor seal between the adiabatic space and the reactor chamber is retained regardless of the heat expansion of this inner shell.
Another object of the present invention is to provide a reactor having pipe means for the inlet and outlet which are perpendicular to each other and wherein the inner shell is so supported on the outer shell that the inner shell may slide sealingly, in an axial direction relative to one of the pipe means, while the other pipe means is so constructed that the inner shell may move in an axial direction and in a direction normal to the axis of the other pipe means.
A further object of the present invention is to provide a reactor which includes means to fix any point of the inner shell with respect to the outer shell to eliminate vibration and noise by the inner shell due to the pressure of exhaust gas.
The other object, advantages and features of the present invention will become further apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a lateral sectional view of one embodiment of a reactor according to the present invention.
FIG. 2 is a longitudinal sectional view of the reactor taken along the line II -- II in FIG. 1.
FIG. 3 is a lateral sectional view of the main portion of another embodiment of the reactor of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will be described with reference to FIGS. 1 and 2. A reactor 1 comprises an inner shell 3 forming a reaction chamber 2 and an outer shell 5 surrounding the outside of the inner shell 3 through an adiabatic space 4. The inner shell 3 comprises an upper inner shell section 3a and lower inner shell section 3b, and pin 6 and a shaft tube 8 forming an exhaust gas port 7, fixed to respective outside ends thereof. The outer shell 5 comprises an upper outer shell section 5a and lower outer shell section 5b, and a fulcrum shaft 9 and an exhaust gas tube 10 fixed to respective inside ends for supporting the inner shell 3. Since the pin 6 and fulcrum shaft 9, and shaft tube 8 and exhaust gas tube 10 are supported in slidable engagement with each other, the inner shell 3 may expand and contract in the axial direction of the shaft tube 8 in the outer shell 5. Reburned gas is exhausted toward the exhaust gas tube passing through the shaft tube 8. Further, the adiabatic space 4 formed between the outer shell 5 and the inner shell 3 is filled, if required, by a heat insulating material. The inner shell 3 includes a first opening 11 and second openings 12 forming the outlet and inlets respectively for the exhaust gas. The shaft tube 8 is fixed to the inner shell 3 at the first opening 11, but if desired, the inner shell 3 may slide on the shaft tube 8 at the first opening 11 with the shaft tube fixed to the outer shell 5. The inner shell 3 is fixed to the inner end of pipes 13 extending through the outer shell 5 at the second openings 12. Openings 14 within the outer shell 5 are at positions corresponding to the second openings 12 within the inner shell 3 but are larger than the outer diameter of the pipes 13 so as not to restrict the movement of the pipes 13 therethrough. An auxiliary base 15 is spaced from the pipe 13 so as not to restrict the movement of the pipe 13. Flanges 16 fixed to the outer shell 5 allow installing of the reactor 1 to the engine block. A cylindrical sealing member 17 comprises an annular rim 18 and is interleaved sealingly and slidably between the auxiliary base 15 and each flange 16. Each sealing member 17 has an opening 19 corresponding to the outer periphery of its pipe 13, and is slidably and sealingly engaged with the pipe 13. Sealing member 17 may be plate formed only of an annular rim 18. Thus, the annular rim 18 of the sealing member 17 and the inner peripheral surface of the opening 19 are so constructed that the spaces between the auxiliary base 15. flange 16 and the outer peripheral surfaces of pipe 13, respectively are very small so as not to pass the exhaust gas into the heat insulating space 4.
Inner pipes 20 form a duct in connection with the reaction chamber 2 and the engine block, through the pipes 13. This inner pipe 20 is inserted into the flange 16 so that the flange 16 is fixed to the engine block with the result that pipe 20 is fixed to the block. The inner pipe 20 has a smaller outer diameter than the inner diameter of the pipe 13 so as not to restrict the movement of the pipe 13. Since the inner pipe 20 is a duct uniform in section from the engine block of the reaction chamber 2, it decreases the exhausting resistance of the exhaust gas.
Since the inner pipe 20 may be heat resistance treated separately from the reactor, its expense is reduced. Further, since it employs the inner pipe 20 as double layer at the passage to the reaction chamber 2 by the pipe 13, the performance of the reactor 1 is improved. A supporting plate 21 is disposed generally intermediate between two pipes 13, the center of which is fixed to the inner surface of the flange 16 by a bolt 22 at the same time the end of which is fixed onto the outer surface of the upper inner shell 3a. Since the inner shell 3 is slidably supported with respect to the outer shell 5 by the pin 6 and shaft tube 8, the supporting plate 21 prevents the vibration of the engine, dynamic pressure of the exhaust gas and the generation of the noise due to the reburning of the exhaust gas in the combustion chamber 2. It is preferable that this supporting plate 21 is provided at the place which is least affected by the expansion and contraction of the inner shell 3, for example at the center of the two pipes 13 as in the embodiment, and further if flexible material is used, it is further effective for absorbing the expansion and contraction of the inner shell 3.
In this embodiment, the sealing member 17 is sealingly and slidably interleaved by the flange 16 fixed to the outer shell 5 and the auxiliary base 15 so that the pipe 13 is sealingly and slidably inserted into the sealing member 17 with the result that the inner end of the pipe 13 is fixed to the inner shell 3. Further, the pin 6 and the shaft tube 8 are slidably and sealingly supported on the outer shell 5. Accordingly, if the inner shell 3 is heated and expands, in the direction normal to the axis of the pipe 13 by means of the heat held by the exhaust gas itself and the reburning heat, the pipe 13 fixed to the inner shell 3 and sealing member 17 and shaft tube 8 remains sealed between the reaction chamber 2 and the adiabatic space 4 in a direction normal to the axis together with the inner shell 3 so as to move therewith. If the inner shell 3 and the pipe 13 expand in the axial direction of the pipe 13, the pipe 13 moves sealingly between the reaction chamber 2 and the adiabatic space 4 in an axial direction, because the pipe 13 is slidably inserted into the sealing member 17. The disc surface 18 of the sealing member 17 is sealingly and slidably interleaved between the engine block and the outer shell 5 as between the outer shell 5 and the flange 16, between the flange 16 and the engine block, and between the flange 16 and the flange portion of the inner pipe 20. Accordingly, if the inner pipe 20 and auxiliary base 15 are, for example, omitted so that the sealing member 17 is sealingly and slidably interleaved between the outer shell 5 and the flange 16, the object and effectiveness of the present invention may be performed.
In the present embodiment, the inlet comprises pipes 13 and the outlet is shaft tube 8, but these may be reversed in construction so as to obtain the same effect. Therefore, as has been described heretofore, the inner shell 3 expands in the direction of the pin 6 and the shaft tube 8 at the boundary generally intermediate between the inner shell 3 and the two pipes 13. In this case, the pipe 13 fixed to the upper inner shell 3a at the inner end thereof may move in the axial direction and in the direction normal to the axis, and accordingly the inner shell 3 may freely expand and contract without restriction. For this reason, cracks will not occur in the inner shell 3 and the outer shell 5 as do conventional ones, and remarkable effects are provided for further improving the durability of the reactor. Further, since the inner shell 3 is fixed to the flange 16 or outer shell 5 at a position without affecting the expansion and contraction of the inner shell 3, it provides great effects such as preventing the generation of the noise due to the vibration of the engine, dynamic pressure of the exhaust gas and reburning.
If the inner shell 3 and the outer shell 5 forming the reactor body are divided into upper and lower two sections to be pressed together so that their outer edges are coupled by the methods such as by welding to each other, it may be easily manufactured.
Further, while supporting plate 21 fixed the upper inner shell section to the flange, at a single position where the expansion and contraction of the inner shell 3 are small, any point of the inner shell 3 may be fixed with respect to the outer shell 5 by similar means.
A dotted line 23 illustrates a baffle plate for changing the flow of the exhaust gas so as to hold the retaining time of the exhaust gas in the reaction chamber 2, with the result that the combustion time of the gas in the reaction chamber 2 is increased so that the combustion of the unburned components is improved. If this baffle plate 23 is installed at the end of the inner pipe 20, the flow of the exhaust gas may be varied and the dynamic pressure of the exhaust gas may not act directly on the inner shell 3, and accordingly, the durability of the inner shell 3 may be improved at the same time noise of the inner shell 3 due to the dynamic pressure may also be eliminated.
A second embodiment will now be described with reference to FIG. 3. In this embodiment, the inlet portion of the first embodiment is altered. The difference from the first embodiment is such that the inner end of the pipe 13 is not fixed to the opening 12 of the inner shell 3 but sealingly and slidably engaged. The sealing member 17 is fixed integrally to the outer end of the pipe 13. Therefore, the disc surface of the pipe 13 is slidably and sealing interleaved between the engine block and the outer shell 5 similar to the first embodiment. Accordingly, the pipe 13 may move sealingly together with the inner shell 3 similar to the first embodiment with respect to the expansion of the inner shell in the direction normal to the axis of the pipe 13. If the inner shell 3 expands and contracts in the axial direction of pipe 13, only the inner shell 3 moves sealingly along the outer periphery of pipe 13. Thus, this second embodiment also is for the same effects as the first embodiment.