Title:
WING WITH SLOTTED FLAP MOUNTED AT THE LEADING EDGE AND/OR AT THE TRAILING EDGE
United States Patent 3638886
Abstract:
This invention relates to a slotted flap adapted to be mounted on at least one edge of a wing and adapted to be pivoted outwardly therefrom, comprising a first portion positioned uppermost in the retracted condition, and a second lower portion mounted on said first portion for pivotal movement about the outer edge of said first portion, both portions constituting independent slotted flaps in the extended condition thereof.
US Patent References:
Supporting surface for flying machines
Ksoll - November 1938 - 2137879
Airplane flap with slot controller
Grant - June 1951 - 2556326
LEADING EDGE FLAP OF VARIABLE CAMBER AND THICKNESS
Alvarez-Calderon - August 1970 - 3524610
Inverting flap system
Alvarez-Calderon - March 1968 - 3371888
Supporting surface for flying machines
Ksoll - November 1938 - 2137879
Airplane flap with slot controller
Grant - June 1951 - 2556326
LEADING EDGE FLAP OF VARIABLE CAMBER AND THICKNESS
Alvarez-Calderon - August 1970 - 3524610
Inverting flap system
Alvarez-Calderon - March 1968 - 3371888
Application Number:
05/009790
Publication Date:
02/01/1972
Filing Date:
02/09/1970
View Patent Images:
Export Citation:
Assignee:
Dornier G. M. B. H. (Friedrichshafen, Bodensee, DT)
Primary Class:
Other Classes:
244/216
International Classes:
B64C3/38; B64C9/14; B64C3/00; B64C9/00; B64C9/14
Field of Search:
244/42R,42CA,42CB,42D,42DA,42DB,43,44
Primary Examiner:
Blix, Trygve M.
Assistant Examiner:
Forman, Jeffrey L.
Claims:
What is claimed is
1. A slotted flap adapted to be mounted on at least one edge of a wing and adapted to be pivoted outwardly therefrom, comprising a first portion positioned uppermost in the retracted condition, a second lower portion mounted on said first portion for pivotal movement about the outer edge of said first portion, both portions constituting independent slotted flaps in the extended condition thereof, and means for pivoting both of said first and second portions parallel to the main plane of the wing during extending and retracting operations.
2. A slotted flap according to claim 1 including guide rod means hingedly mounted at one end at the wing and hingedly engaging at the other end thereof with said second lower portion at a distance from the pivot axis of the latter, in the manner of a connecting rod.
3. A slotted flap according to claim 1 including a hydraulically acting control motor connected between the wing and said second lower portion, the motor being actuatable independently of the movement of said first portion.
1. A slotted flap adapted to be mounted on at least one edge of a wing and adapted to be pivoted outwardly therefrom, comprising a first portion positioned uppermost in the retracted condition, a second lower portion mounted on said first portion for pivotal movement about the outer edge of said first portion, both portions constituting independent slotted flaps in the extended condition thereof, and means for pivoting both of said first and second portions parallel to the main plane of the wing during extending and retracting operations.
2. A slotted flap according to claim 1 including guide rod means hingedly mounted at one end at the wing and hingedly engaging at the other end thereof with said second lower portion at a distance from the pivot axis of the latter, in the manner of a connecting rod.
3. A slotted flap according to claim 1 including a hydraulically acting control motor connected between the wing and said second lower portion, the motor being actuatable independently of the movement of said first portion.
Description:
This invention relates to a wing having a slotted flap mounted at the leading edge and/or at the trailing edge thereof, the flap being adapted to be pivoted outwardly by means of a parallelogram guide approximately in the wing plane.
As is known, slotted flaps of this type serve for preventing a flow separation at the wing, during the landing approach of an aircraft, within as large a pitch angle range as possible. In order to attain this objective, a large number of different flap constructions and designs already have been examined with regard to the aerodynamic effectiveness thereof. It has been found that flap systems which consist of several mutually coordinated flaps are much more effective from an aerodynamic standpoint than are individual flaps.
The advantages which may be obtained with flap systems are, however, accompanied by disadvantages which result from the complicated construction thereof and particularly those which result from the displacing mechanism employed as well as the more difficult mounting of the flaps. There arise, therefore, considerable mechanical and kinematic problems for the design and construction of such flap systems at the wing.
In one known construction, the flap system at the trailing edge is composed of a main setting or regulating surface and an auxiliary setting surface coordinated thereto, the main setting surface being rearwardly extendible from out of the wing by means of a lever system and pivotal in this position. The auxiliary setting surface, being carried by the main setting surface, is pivoted out of the retracted position thereof by means of an articulated parallelogram approximately in the plane of the main setting surface. In this known flap system, the displacing or adjusting mechanism and the positioning or mounting of the setting surfaces is complicated and requires considerable mechanical equipment. In addition thereto, the flow is considerably disturbed by the displacing mechanism for the setting surfaces, particularly during high-speed flight.
It is also known from the aforementioned construction to mount, between the wing and the auxiliary setting surface, a guide or control member which brings about, in case of a displacement of the main setting surface, a forced displacement of the auxiliary setting surface.
The construction of the present invention greatly simplifies the arrangement and mounting, as well as the displacing mechanism, of flap systems mounted at the leading edge of the wing and/or at the trailing edge and provides a construction such that the flow at the wing is impaired to the smallest degree possible, both for the retracted and extended position of the flaps.
These results are obtained by virtue of the fact that the flap consists, in the retracted position, of an upper portion mounted at the wing and of a second lower portion which is adapted to be pivoted out, in the manner of a hinge, about the outer edge of the upper portion. In the extended position, both parts constitute independent slotted flaps.
A flap system constructed in this manner affords the essential advantage of a kinematically favorable mounting and the displacing mechanism necessary for pivoting the flaps has a simple construction with only a small number of structural elements. Furthermore, in the extended position of the flaps, the displacing mechanism requires only a limited amount of space within the wing so that the supporting construction of the wing is not thereby impaired. In addition thereto, none of the elements or parts of the displacing mechanism is mounted outside of the outer contour of the wing profile, in the retracted position of the flaps, and disturbance of the flow at the wing during high-speed flight is completely eliminated. A perfect flow or circulation around the wing is assured in the retracted position of the flaps. The closing gaps present in the retracted position influence the flow only to a limited extent. The flap portion which is positioned downwardly in the retracted position of the flap systems may be given an aerodynamically favorable configuration both for the extended position as well as for the retracted position.
According to a further feature of the present invention, a guide rod is hingedly supported at the main wing and, at the other end thereof, engages the lower flap portion at a distance from the pivot axis of the latter in the manner of a connecting rod. Thus, when the upper part of the slotted flap is pivoted out, a folding-out of the lower part of the slotted flap is, of necessity, also accomplished in a simple manner with few structural elements as a result of this forced operative connection between the main wing and the lower portion of the slotted flap. An additional actuating linkage or lever system for the lower portion of the slotted flap is, therefore, effectively eliminated.
According to a further feature of the present invention, the guide or control member mounted between the main wing and the lower flap portion may be substituted by a hydraulically acting control motor which may be actuated independently of the displacing movement of the upper flap portion. This has the effect that both flap portions are brought into the extended position thereof and the flap portion which is connected to the control motor is displaced independently of the other flap portion.
In addition, it also is possible that the flap portion being connected to the control motor may have a superimposed pivoting movement imparted thereto during the extending movement thereof.
Two embodiments of the present invention are illustrated in the accompanying drawings in which
FIG. 1 shows the general concept in a top plan view of the arrangement and actuation of the flaps at the leading edge of the wing, the flaps being in the retracted position thereof,
FIG. 2 illustrates the flaps of FIG. 1 in the extended position thereof,
FIGS. 3 to 5 are cross-sectional views of different positions of the slotted jet flaps,
FIG. 6 is a cross-sectional view through the wing and illustrates the mounting and displacing mechanisms for the slotted jet flaps,
FIG. 7 is a top plan view according to FIG. 6, and
FIG. 8 is a top plan view of a further embodiment of the displacing mechanism for the second slotted jet flap shown in FIG. 7.
In the embodiments illustrated in the drawings, two slotted flap systems are each mounted at the leading edge of the wing on both sides of an aircraft fuselage. In the interest of simplicity, only one of these flap systems will be described in detail hereinafter. The flap systems are shown in the retracted position thereof in FIG. 1 and in the extended position thereof in FIG. 2. As indicated in FIGS. 1 through 7, reference numeral 1 is employed to identify the aircraft fuselage while reference numeral 2 designates the wing. Each of the flap systems consists of the flap portions 3 and 4 which are displaceable by the pilot by means of a linkage or lever system 8, as shown in FIG. 2.
As shown in FIGS. 3 to 7, the flap portions 3 and 4, when in the retracted position thereof, constitute the leading edge of the wing 2. The upper flap portion 3 is mounted at the main wing 2 by means of two supporting arms 12. The supporting arms 12 include at the ends thereof the pivot axes 16 and 17, respectively, which are guided in the bearing points 13 and 14, respectively, at the flap portion 3 and at the main wing 2, respectively. In the embodiment shown, the pivot axes 16 and 17 are parallel with respect to each other and are mounted at right angles to the main plane of the wing 2. The second flap portion 4, in turn, is pivotally mounted at the flap portion 3 by means of two pivot arms 20. One end of each of the pivot arms 20 is secured in the area of the trailing edge of the second flap portion 4 and is in operative engagement at the other end thereof, by means of the bearing bores 26 with the pivot axes 28 therein, with the flap portion 3. In the extended position of the flap portions 3 and 4, a jet gap 47 is formed between the main wing and the flap portion 3, and a jet gap 48 is formed between the flap portion 3 and the flap portion 4. In the retracted position of the flap systems, the flap portions 3 and 4 constitute the leading edge of the wing profile, the upper side 40 of the flap portion 3 being positioned at the upper side, and the upper side 42 of the flap portion 4 being positioned at the lower side or bottom of the wing profile. The main wing 2 includes, at the bottom side thereof and in the forward area thereof, a recess 43 into which the flap portion 4 may be folded in the retracted position thereof.
Inserted between the main wing 2 and the flap portion 4 is a guide or control member 32, one end of which is supported at the main wing 2 by means of a hinge 37 and the other end of which engages at the flap portion 4 by means of the hinge 36. The hinged mounting 36, i.e., the point of engagement of the guide or control member 32 at the flap portion 4 is positioned at a certain distance from the pivot axes 28 so that, together with the guide member 32, a crank assembly is formed. In the retracted position of the flap systems, the forward or leading edge 44 of the flap portion 4 then will point in the direction toward the trailing edge of the wing. Accordingly, the two flap portions 3 and 4 are folded open in the manner of a hinge from the retracted position into the extended position thereof. A displacing linkage or lever system 8 serves for actuating the flap portions 3 and 4, as already has been set forth above, and is connected at one end to an actuating member for the pilot and at the other end to the pivot arms for purposes of the joint pivoting of the flap portions 3 and 4 in the wing plane. The displacing linkage 8 may be actuated in known manner by means of a servomotor, for example.
As is apparent from FIG. 8, the guide or control member 32, according to FIGS. 6 and 7, also may be a hydraulically acting control motor 52. The control motor 52 in this case comprises a double-acting hydraulic piston 53 which is displaceable in the cylinder 54 in both directions. The piston rod 56 of the piston 53 is connected in this case to the main wing by means of a hinge 57 while the cylinder 54 is connected to the flap portion 4 by means of a hinge 58. Actuation of the control motor 52 is effected by means of a pressure medium control device, not shown, which may be operated by the pilot.
The operation of the embodiment shown in FIGS. 1 through 7 is as follows:
During the high-speed flight of the aircraft, both flap portions 3 and 4 of the flap systems constitute the forward or leading edge of the wing 2. If it is intended to extend the flap portions 3 and 4, for example for landing approach, the pivot arms 12 are pivoted by way of the operating linkage 8 and, hence, the flap portions 3 and 4 in the plane of the wing are moved out of the retracted position thereof. At the same time, the flap portion 4 is pivoted, about the pivot axes 28, out of the recess 43 in the main wing 2, by means of the guide or control member 32, into the extended position thereof, as shown in FIGS. 2, 5, and 6. The retracting operation of both flap portions 3 and 4, respectively, is effected analogously to the extending operation just described but in the inverse sequence.
In the embodiment shown in FIG. 8, the flap portion 4 may be pivoted, with the aid of the control motor 52, independently of the position of the flap portion 3. It is further possible to bring both flap portions into the extended position thereof and to move the flap portion 4 from this extended position, by actuation of the control motor 52, in the sense of either an increase or decrease in the pitch angle thereof, independently of the position of the flap portion 3. By means of the control motor 52 it also is possible, however, to impart to the flap portion 4, as compared to the flap portion 3 and within the extending movement of both of these flap portions, a pivoting movement which is superimposed with respect to the extending movement.
The flap systems as described in the foregoing embodiments are not limited to the mounting thereof at the leading edge of the wing but also may be employed at the trailing edge. Also, the flap systems according to the present invention may be employed both at the leading edge and at the trailing edge of the wing.
It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.
As is known, slotted flaps of this type serve for preventing a flow separation at the wing, during the landing approach of an aircraft, within as large a pitch angle range as possible. In order to attain this objective, a large number of different flap constructions and designs already have been examined with regard to the aerodynamic effectiveness thereof. It has been found that flap systems which consist of several mutually coordinated flaps are much more effective from an aerodynamic standpoint than are individual flaps.
The advantages which may be obtained with flap systems are, however, accompanied by disadvantages which result from the complicated construction thereof and particularly those which result from the displacing mechanism employed as well as the more difficult mounting of the flaps. There arise, therefore, considerable mechanical and kinematic problems for the design and construction of such flap systems at the wing.
In one known construction, the flap system at the trailing edge is composed of a main setting or regulating surface and an auxiliary setting surface coordinated thereto, the main setting surface being rearwardly extendible from out of the wing by means of a lever system and pivotal in this position. The auxiliary setting surface, being carried by the main setting surface, is pivoted out of the retracted position thereof by means of an articulated parallelogram approximately in the plane of the main setting surface. In this known flap system, the displacing or adjusting mechanism and the positioning or mounting of the setting surfaces is complicated and requires considerable mechanical equipment. In addition thereto, the flow is considerably disturbed by the displacing mechanism for the setting surfaces, particularly during high-speed flight.
It is also known from the aforementioned construction to mount, between the wing and the auxiliary setting surface, a guide or control member which brings about, in case of a displacement of the main setting surface, a forced displacement of the auxiliary setting surface.
The construction of the present invention greatly simplifies the arrangement and mounting, as well as the displacing mechanism, of flap systems mounted at the leading edge of the wing and/or at the trailing edge and provides a construction such that the flow at the wing is impaired to the smallest degree possible, both for the retracted and extended position of the flaps.
These results are obtained by virtue of the fact that the flap consists, in the retracted position, of an upper portion mounted at the wing and of a second lower portion which is adapted to be pivoted out, in the manner of a hinge, about the outer edge of the upper portion. In the extended position, both parts constitute independent slotted flaps.
A flap system constructed in this manner affords the essential advantage of a kinematically favorable mounting and the displacing mechanism necessary for pivoting the flaps has a simple construction with only a small number of structural elements. Furthermore, in the extended position of the flaps, the displacing mechanism requires only a limited amount of space within the wing so that the supporting construction of the wing is not thereby impaired. In addition thereto, none of the elements or parts of the displacing mechanism is mounted outside of the outer contour of the wing profile, in the retracted position of the flaps, and disturbance of the flow at the wing during high-speed flight is completely eliminated. A perfect flow or circulation around the wing is assured in the retracted position of the flaps. The closing gaps present in the retracted position influence the flow only to a limited extent. The flap portion which is positioned downwardly in the retracted position of the flap systems may be given an aerodynamically favorable configuration both for the extended position as well as for the retracted position.
According to a further feature of the present invention, a guide rod is hingedly supported at the main wing and, at the other end thereof, engages the lower flap portion at a distance from the pivot axis of the latter in the manner of a connecting rod. Thus, when the upper part of the slotted flap is pivoted out, a folding-out of the lower part of the slotted flap is, of necessity, also accomplished in a simple manner with few structural elements as a result of this forced operative connection between the main wing and the lower portion of the slotted flap. An additional actuating linkage or lever system for the lower portion of the slotted flap is, therefore, effectively eliminated.
According to a further feature of the present invention, the guide or control member mounted between the main wing and the lower flap portion may be substituted by a hydraulically acting control motor which may be actuated independently of the displacing movement of the upper flap portion. This has the effect that both flap portions are brought into the extended position thereof and the flap portion which is connected to the control motor is displaced independently of the other flap portion.
In addition, it also is possible that the flap portion being connected to the control motor may have a superimposed pivoting movement imparted thereto during the extending movement thereof.
Two embodiments of the present invention are illustrated in the accompanying drawings in which
FIG. 1 shows the general concept in a top plan view of the arrangement and actuation of the flaps at the leading edge of the wing, the flaps being in the retracted position thereof,
FIG. 2 illustrates the flaps of FIG. 1 in the extended position thereof,
FIGS. 3 to 5 are cross-sectional views of different positions of the slotted jet flaps,
FIG. 6 is a cross-sectional view through the wing and illustrates the mounting and displacing mechanisms for the slotted jet flaps,
FIG. 7 is a top plan view according to FIG. 6, and
FIG. 8 is a top plan view of a further embodiment of the displacing mechanism for the second slotted jet flap shown in FIG. 7.
In the embodiments illustrated in the drawings, two slotted flap systems are each mounted at the leading edge of the wing on both sides of an aircraft fuselage. In the interest of simplicity, only one of these flap systems will be described in detail hereinafter. The flap systems are shown in the retracted position thereof in FIG. 1 and in the extended position thereof in FIG. 2. As indicated in FIGS. 1 through 7, reference numeral 1 is employed to identify the aircraft fuselage while reference numeral 2 designates the wing. Each of the flap systems consists of the flap portions 3 and 4 which are displaceable by the pilot by means of a linkage or lever system 8, as shown in FIG. 2.
As shown in FIGS. 3 to 7, the flap portions 3 and 4, when in the retracted position thereof, constitute the leading edge of the wing 2. The upper flap portion 3 is mounted at the main wing 2 by means of two supporting arms 12. The supporting arms 12 include at the ends thereof the pivot axes 16 and 17, respectively, which are guided in the bearing points 13 and 14, respectively, at the flap portion 3 and at the main wing 2, respectively. In the embodiment shown, the pivot axes 16 and 17 are parallel with respect to each other and are mounted at right angles to the main plane of the wing 2. The second flap portion 4, in turn, is pivotally mounted at the flap portion 3 by means of two pivot arms 20. One end of each of the pivot arms 20 is secured in the area of the trailing edge of the second flap portion 4 and is in operative engagement at the other end thereof, by means of the bearing bores 26 with the pivot axes 28 therein, with the flap portion 3. In the extended position of the flap portions 3 and 4, a jet gap 47 is formed between the main wing and the flap portion 3, and a jet gap 48 is formed between the flap portion 3 and the flap portion 4. In the retracted position of the flap systems, the flap portions 3 and 4 constitute the leading edge of the wing profile, the upper side 40 of the flap portion 3 being positioned at the upper side, and the upper side 42 of the flap portion 4 being positioned at the lower side or bottom of the wing profile. The main wing 2 includes, at the bottom side thereof and in the forward area thereof, a recess 43 into which the flap portion 4 may be folded in the retracted position thereof.
Inserted between the main wing 2 and the flap portion 4 is a guide or control member 32, one end of which is supported at the main wing 2 by means of a hinge 37 and the other end of which engages at the flap portion 4 by means of the hinge 36. The hinged mounting 36, i.e., the point of engagement of the guide or control member 32 at the flap portion 4 is positioned at a certain distance from the pivot axes 28 so that, together with the guide member 32, a crank assembly is formed. In the retracted position of the flap systems, the forward or leading edge 44 of the flap portion 4 then will point in the direction toward the trailing edge of the wing. Accordingly, the two flap portions 3 and 4 are folded open in the manner of a hinge from the retracted position into the extended position thereof. A displacing linkage or lever system 8 serves for actuating the flap portions 3 and 4, as already has been set forth above, and is connected at one end to an actuating member for the pilot and at the other end to the pivot arms for purposes of the joint pivoting of the flap portions 3 and 4 in the wing plane. The displacing linkage 8 may be actuated in known manner by means of a servomotor, for example.
As is apparent from FIG. 8, the guide or control member 32, according to FIGS. 6 and 7, also may be a hydraulically acting control motor 52. The control motor 52 in this case comprises a double-acting hydraulic piston 53 which is displaceable in the cylinder 54 in both directions. The piston rod 56 of the piston 53 is connected in this case to the main wing by means of a hinge 57 while the cylinder 54 is connected to the flap portion 4 by means of a hinge 58. Actuation of the control motor 52 is effected by means of a pressure medium control device, not shown, which may be operated by the pilot.
The operation of the embodiment shown in FIGS. 1 through 7 is as follows:
During the high-speed flight of the aircraft, both flap portions 3 and 4 of the flap systems constitute the forward or leading edge of the wing 2. If it is intended to extend the flap portions 3 and 4, for example for landing approach, the pivot arms 12 are pivoted by way of the operating linkage 8 and, hence, the flap portions 3 and 4 in the plane of the wing are moved out of the retracted position thereof. At the same time, the flap portion 4 is pivoted, about the pivot axes 28, out of the recess 43 in the main wing 2, by means of the guide or control member 32, into the extended position thereof, as shown in FIGS. 2, 5, and 6. The retracting operation of both flap portions 3 and 4, respectively, is effected analogously to the extending operation just described but in the inverse sequence.
In the embodiment shown in FIG. 8, the flap portion 4 may be pivoted, with the aid of the control motor 52, independently of the position of the flap portion 3. It is further possible to bring both flap portions into the extended position thereof and to move the flap portion 4 from this extended position, by actuation of the control motor 52, in the sense of either an increase or decrease in the pitch angle thereof, independently of the position of the flap portion 3. By means of the control motor 52 it also is possible, however, to impart to the flap portion 4, as compared to the flap portion 3 and within the extending movement of both of these flap portions, a pivoting movement which is superimposed with respect to the extending movement.
The flap systems as described in the foregoing embodiments are not limited to the mounting thereof at the leading edge of the wing but also may be employed at the trailing edge. Also, the flap systems according to the present invention may be employed both at the leading edge and at the trailing edge of the wing.
It will be obvious to those skilled in the art that many modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications.