JP4457718B2 - Car front subframe - Google Patents

Description

  The present invention provides a front sub-frame including a side frame disposed on a lower side of a body frame of an automobile and extending in the vehicle front-rear direction, and an impact absorbing member is provided on the front side of the side frame in the vehicle front-rear direction. Belongs to the technology.

  Conventionally, as described in, for example, Patent Document 1 below, a vehicle body frame (e.g., equivalent to the front side member 12 in Patent Document 1) below a vehicle body frame (e.g., a vehicle) is provided along the vehicle longitudinal direction. It is known to install a front sub-frame composed of a pair of left and right side frames extended to the front side to the vicinity of the front end.

  Further, as in Patent Document 1, an impact absorbing member (corresponding to the protruding portion 24 in Patent Document 1) that is fixed to the front end part and extends forward is provided at the front end part of the side frame. Is also described.

With such a configuration, for example, a frontal collision between the vehicle and an obstacle lower than the height of the front end of the vehicle body frame of the vehicle, the impact load is received by the vehicle body frame substantially linearly when viewed from the vehicle width direction. If this is not possible, such a collision load can be received substantially linearly when viewed from the vehicle width direction by the front sub-frame positioned below the vehicle body frame. In this case, since the impact energy can be absorbed by the impact absorbing member, the collision load can be further reduced.
Utility Model Registration No. 2514565

  By the way, it is desirable to reduce the weight of the vehicle as a whole, and even the above-described front subframe that receives a large amount of collision load is strongly required to be reduced in weight up to details.

  On the other hand, the front sub-frame is composed of a pair of left and right side frames extending in the vehicle front-rear direction, and the front end support portion in the vicinity of the front end portion is normally supported by the body frame by an inner and outer cylindrical rubber bush. However, this rubber bush is relatively heavy. Therefore, it is conceivable to reduce the weight by reducing the size of the rubber bush itself.

  However, when the inner and outer cylindrical rubber bushes are reduced in size and reduced in weight, the following problems occur.

  In order to reduce the size of the inner and outer cylindrical rubber bushes, it is conceivable to reduce the length in the axial direction of the inner cylindrical rubber bushes in consideration of vibration reduction performance, which is a function of the rubber bushes themselves. Thereby, since the rubber bush is usually set so that the axial direction of the inner cylinder is along the vertical direction, the length (thickness) of the rubber bush in the vertical direction is shortened.

  In this case, it is conceivable to shorten the length of the rubber bush in the vertical direction without greatly changing the outer shape in the vicinity of the front end portion of the side frame. At that time, in order to support the lower part of the rubber bush, a reinforcing member for fixing the lower part of the rubber bush is provided between the upper surface and the lower surface of the side frame in the vicinity of the front end portion of the side frame. There must be. According to such a technique, the work of providing a reinforcing member inside the side frame is newly required, and there arises a problem that productivity deteriorates.

  On the other hand, it is conceivable that the lower surface of the side frame is positioned on the upper side at the front end portion of the side frame and the vicinity thereof, and the lower portion of the rubber bush is fixedly supported by the lower surface.

  However, this shortens the vertical length of the front end portion of the side frame. On the other hand, the vertical length (thickness) of the shock absorbing member fixed to the front end of the side frame determines the impact energy absorption. Cannot be significantly shortened.

  Accordingly, when a collision load applied from the front of the shock absorbing member is transmitted to the front end portion of the side frame, the front end portion of the side frame having a short vertical width and a low rigidity from the wide shock absorbing member in the vertical direction. The collision load will be transmitted to. As described above, since the support rigidity of the shock absorbing member is lowered at the front end portion of the side frame, the impact energy is not actively absorbed by the shock absorbing member, and the collision load cannot be sufficiently reduced.

  The present invention has been made in consideration of the above-described problems, and its object is to support the vehicle body frame via a front end support portion that is located near the front end portion of the side frame and is made of a rubber bush. At the same time, in the front subframe that has a shock absorbing member on the front side of the front end, the rubber bush at the front end support is downsized while suppressing deterioration in productivity and lowering of rigidity at the front end and its vicinity. This is to reduce the weight.

  In order to achieve such an object, in the invention according to claim 1 of the present invention, a front end support portion that extends in the vehicle front-rear direction on the lower side of the body frame and is located in the vicinity of the front end portion, and A side frame supported by the vehicle body frame by a support portion at a predetermined position on the rear side of the front end support portion, and an impact that is fixed to the front end portion and extends to the front side of the vehicle so as to absorb an impact at the time of collision. In the front subframe of an automobile constituted by an absorbing member, the front end support portion is cylindrical and is arranged so that the axial direction is substantially along the vertical direction, and the length in the axial direction is the impact. An inner and outer cylindrical rubber bush that is shorter than the length in the vertical direction of the absorbing portion is provided, and the front end portion of the side frame and its vicinity are in the cross section in the vehicle width direction and the inner and outer cylindrical rubber bushes. A substantially rectangular closed cross-section to which the shoe is fixed, and a lower side wall surface extending from both ends of the closed cross-section in the vehicle width direction to a height near where the lower surface of the shock absorbing member is located, The closed cross section and the lower side wall surface extend in the vehicle front-rear direction.

  With such a configuration, the vertical length of the inner and outer cylindrical rubber bushes can be shortened, and thus the rubber bushes themselves can be reduced in size and weight. Further, in this case, the front end portion of the side frame and the vicinity thereof have a substantially rectangular closed cross section in which the rubber bush is installed in the vehicle width direction cross section, and the lower surface of the shock absorbing member from the both ends of the closed cross section in the vehicle width direction. It consists of a lower side wall surface that is formed up to the position where it is located, and these extend over the longitudinal direction of the vehicle, so that the rigidity of the front end and its vicinity due to downsizing of the rubber bush is suppressed. Thus, the support rigidity of the shock absorbing member can be increased, and the impact energy absorbability by the shock absorbing member can be increased.

  Further, there is no need to provide a reinforcing member for fixing the lower portion of the rubber bush, and productivity is not deteriorated.

  According to a second aspect of the present invention, in the first aspect, the front end portion of the side frame and the vicinity thereof bulge upward in the vehicle width direction cross section in the vehicle width direction with respect to the flat both ends in the vehicle width direction. The upper member and the lower member are configured by a flange connection that overlaps in the vertical direction so that the closed cross section is formed, and by this overlapping, in the vicinity of the height where the lower surface of the shock absorbing member is located, A flange portion is formed in the vehicle front-rear direction.

  With such a configuration, the front end portion of the side frame and the vicinity thereof are formed by flange coupling in which the upper member and the lower member are overlapped in the vertical direction, so that the weight of the rubber bush is reduced and the vehicle at the front end portion and the vicinity thereof Productivity can be further improved while suppressing the reduction in rigidity in the front-rear direction. Further, by forming a flange portion in the vicinity of the height of the lower surface of the shock absorbing member in the vehicle front-rear direction, the rigidity at the front end portion and in the vicinity thereof can be further increased, and the shock absorbing member absorbs shock energy. Further increase is possible.

  According to a third aspect of the present invention, in the second aspect, the plate thickness of the upper member is made thicker than the plate thickness of the lower member.

  With such a configuration, the rigidity at the front end portion of the side frame and the vicinity thereof can be further increased, and the impact energy absorbability by the impact absorbing member can be further increased.

According to a fourth aspect of the present invention, in the first aspect, a flange portion that faces the outer side of the side frame is formed across the vehicle front-rear direction from the lower end of the lower side wall surface. .

  With such a configuration, the flange portion is formed in the vicinity of the height of the lower surface of the shock absorbing member in the vehicle front-rear direction, so that the rigidity at the front end portion of the side frame and its vicinity can be further increased, and shock absorption is achieved. It is possible to further improve the absorbability of impact energy by the member.

  As described above, in the invention according to the present invention, the length in the vertical direction of the inner and outer cylindrical rubber bushes constituting the front end support portion can be shortened at and near the front end portion of the side frame of the front subframe. The bush itself can be reduced in size and weight. Further, in this case, the front end portion of the side frame and the vicinity thereof have a substantially rectangular closed cross section in which the rubber bush is installed in the vehicle width direction cross section, and the lower surface of the shock absorbing member from the both ends of the closed cross section in the vehicle width direction. It consists of a lower side wall surface that is formed up to the position where it is located, and these extend over the longitudinal direction of the vehicle, so that the rigidity of the front end and its vicinity due to downsizing of the rubber bush is suppressed. Thus, the support rigidity of the shock absorbing member can be increased, and the impact energy absorbability by the shock absorbing member can be increased.

  Further, there is no need to provide a reinforcing member for fixing the lower portion of the rubber bush, and productivity is not deteriorated.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments according to the present invention will be described with reference to the drawings. The frames and members in each embodiment are made of steel unless otherwise specified.

  FIG. 1 is a view of a front subframe, a vehicle body frame, and the like according to the present embodiment as viewed from the lower surface of the vehicle. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 4 is a sectional view taken along the line BB in FIG. 1, FIG. 5 is a sectional view taken along the line CC in FIG. 1, FIG. 6 is a sectional view taken along the line DD in FIG. Sectional drawing and FIG. 8 are FF sectional views of FIG.

  As shown in FIGS. 1 and 2, the vehicle body frame 1 includes a pair of left and right front side frames 2, 2 extending in the longitudinal direction of the vehicle, and the front side frames 2, 2 behind the front side frames 2, 2. Floor frames 3 and 3 to be connected are arranged. The rear side portions of the front side frames 2 and 2 are formed with kick-up portions 4 and 4 which are inclined rearward and downward, whereby the front end portions of the front side frames 2 and 2 are floor frames. 3 to a certain degree higher than that.

  Wheel housings 5 and 5 for storing front wheels (not shown) are formed in the vicinity of the middle portion of the front side frames 2 and 2 adjacent to the outer side of the vehicle, and a shock absorber for supporting the front wheels is stored near the center thereof. Suspension towers 6 and 6 are formed so as to be turned upside down.

  A bumper frame 7 made of resin extends in the vehicle width direction so as to bridge the front end portion at the front end portions of the front side frames 2 and 2, and an impact buffer member is provided inside the bumper frame 7. ing. In addition, what is called a cross member is not provided in the front side frames 2 and 2 in this embodiment. An engine (not shown) is mounted in an engine room E formed so as to be sandwiched between the front side frames 2 and 2.

A floor panel 8 is provided so as to cover the floor frames 3 and 3 from above, and the vicinity of the front end portion of the floor panel 8 extends upward as it is positioned forward, and the front end portion has a vertical position. A dash panel 10 is formed extending in the direction and upward to separate the engine room E and the vehicle compartment 9. Further, the center portion in the vehicle width direction of the floor panel 8 protrudes upward to form a tunnel portion 11, and the tunnel portion 11 has an engine exhaust pipe (not shown) or a so-called FR type vehicle. The drive shaft and the like are stored.

  Side sills 12 and 12 having a rectangular cross section in the vehicle width direction are formed in the vicinity of the end of the floor panel 8 in the vehicle width direction. The front ends of the floor frames 3 and 3 and the side sills 12 and 12 8, the collision load from the front of the vehicle is partially branched from the floor frames 3, 3 and can be input to the side sills 12, 12.

  Below the front side frames 2, 2, a pair of left and right side frames 14, 14 extending in the vehicle front-rear direction, and a vehicle that bridges the front ends and rear ends of the side frames 14, 14, respectively. A front sub-frame 17 composed of a front cross member 15 and a rear cross member 16 that are extended and fixed in the width direction is disposed.

  Front end support portions 18, 18 are formed at the front end portions of the side frames 14, 14, and rear end support portions 19, 19 are formed at the rear end portions, and slightly forward of the rear cross member 16. Intermediate support portions 21, 21 are formed at the front ends of the intermediate portions of the side frames 14, 14 through the vertical members 20, 20 extending upward from the upper surfaces of the side frames 14, 14. These are supported by rubber bushes at corresponding positions on the lower surfaces of the front side frames 2 and 2 immediately above. As a result, the front sub-frame 17 is supported by the front side frames 2 and 2 at a total of six locations.

  In the present invention, the side frames 14 and 14 are not necessarily supported by the front side frames 2 and 2, and may be any structure constituting the vehicle body frame 1.

  Crash tubes 22 and 22 capable of absorbing impact energy by being positively condensed with respect to a collision load in the vehicle longitudinal direction so as to extend forward from the front ends of the side frames 14 and 14 (claims) The front ends of the crash tubes 22 and 22 are fixed by a reinforcement 23 that extends in the vehicle width direction. The crash tubes 22 and 22 are made of steel and are formed in a cylindrical shape so that the inside is hollow. The reinforcement 23 is made of resin. Moreover, the reinforcement 23 is installed so that it may be located in the substantially downward side of the above-mentioned bumper frame 7. FIG.

  Bending promotion portions 24 and 24 are formed from the rear end sides of the front end support portions 18 and 18 of the side frames 14 and 14 to the trunk portions of the vertical members 20 and 20.

  The bending promoting portions 24, 24 are composed of front portions 25, 25 and rear portions 26, 26. The front portions 25, 25 are formed so as to be inclined rearward and downward, and the rear portion 26 is formed. , 26 are formed substantially horizontally with respect to the rearward direction.

  In the present invention, the inclination angle of the rear portions 26 and 26 with respect to the horizontal may be smaller than the inclination angle of the front portions 25 and 25 with respect to the horizontal. That is, it may be inclined rearward and upward.

The side frames 14, 14 are configured by overlapping two panels having substantially the same shape when viewed from below, that is, an upper panel having a convex section and a lower panel having a concave section. However, the plate thickness of the upper panel 25a and the lower panel 25b forming the front portions 25, 25 is larger than the plate thickness of the upper panel 26a and the lower panel 26b forming the rear portions 26, 26. Accordingly, the strength of the front portions 25, 25 with respect to the vertical bending in the front-rear direction is greater than the strength of the rear portions 26, 26 with respect to the vertical bending in the front-rear direction .

Also, in the rear portion 26, 26 of the side frames 14, 14 from the front end of the rear portion 26, 26 connected to the front portion 25 until a predetermined distance rearward rear portion front portion 26c, The width of 26c (that is, the thickness in the vehicle width direction when viewed from below) is the rear rear part 26d, 26d behind the rear front part 26c, 26c and to the base of the vertical members 20, 20. It is formed so as to be smaller than the width of. Further, the width from the base portion to the rear end portion of the vertical member 20 of the side frames 14, 14 is also formed to be substantially larger than the width of the rear portion front side portions 26c, 26c of the rear portions 26, 26. .

In the present embodiment, the two lower arms 29 and 30 of the suspension mechanism are connected to the side frames 14 and 14 of the front sub-frame 17 so as to be swingable.

  Specifically, as shown in FIG. 3, a front-side lower arm support portion 27 is formed on the vehicle outer side of the rear rear portions 26 d and 26 d of the side frames 14 and 14, and rearward of the vertical members 20 and 20. A rear lower arm support portion 28 is formed on the vehicle outer side of the side frames 14, 14. A front-side lower arm 29 and a rear-side lower arm 30 are swingably connected to the front-side lower arm support portion 27 and the rear-side lower arm support portion 28 toward the vehicle outward side. Each outer side end of the rear side lower arm 30 is swingably connected to a wheel support (not shown) that directly supports the front wheel. Further, although not shown, the upper arm connected to the front side frames 2 and 2 is also connected to the wheel support, and the suspension mechanism is formed by these configurations.

In the present invention, the front side lower arm 29 and the rear side lower arm 30 have been described as separate bodies. However, the lower arm is a so-called A-type lower arm, and the front side lower arm 29 and the rear side lower arm 30 are fixed on the outer side of the vehicle. It may be.
(Operation and effect by the structure of the front sub-frame 17)
With the configuration of the front sub-frame 17 as described above, the following operations and effects are achieved.

  First, when the vehicle collides forward with an obstacle with a low height, the collision load received from the obstacle is input to the reinforcement 23 and the crash pipes 22 and 22 while these are compressed in the front-rear direction. By condensation (refer to the dashed line in FIG. 2), the impact energy is absorbed and the impact load is reduced to some extent. In addition, since the reinforcement 23 extends in the vehicle width direction, even when an obstacle collides with only the middle part of the left and right crash tubes 22, 22, the impact load can be transmitted to the crash tubes 22, 22. Thereby, the impact load can be reduced.

  If the degree of collision is slight, the collision load can be made substantially zero by simply condensing the crash tubes 22 and 22 and the reinforcement 23. However, when the degree of collision is large and the collision load is large, the collision load that has not been absorbed by the crash pipes 22 and 22 and the reinforcement 23 is an abbreviation of the front subframe 17, particularly the side frames 14 and 14. Input is performed from front to back along the front-rear direction. In this case, due to the action of the front end support parts 18 and 18 and the intermediate support parts 21 and 21 of the side frames 14 and 14 and the action of the front parts 25 and 25 and the rear parts 26 and 26 of the bending promotion parts 24 and 24, The side frames 14 and 14 are positively bent downward with the bending promoting portions 24 and 24 as the center, whereby the impact energy is absorbed and the collision load is reduced.

  Specifically, the side frames 14, 14 are connected and supported to the front side frames 2, 2 by front end support portions 18, 18 and intermediate support portions 21, 21, and in front of the bending promotion portions 24, 24. The portions 25 and 25 are inclined rearward and downward, whereas the rear portions 26 and 26 are configured to be substantially horizontal.

  Accordingly, due to the collision load input from the front ends of the side frames 14 and 14, the front end portions of the side frames 14 and 14 are displaced rearward while maintaining substantially the same height without significantly reducing the height. On the other hand, the intermediate support portions 21 and 21 of the side frames 14 and 14 are firmly connected to the side frames 14 and 14 via the vertical members 20 and 20. Therefore, a moment acts around the connection portion between the front portions 25, 25 and the rear portions 26, 26 of the bending promoting portions 24, 24, and the front portions 25, 25 and the rear portions 26, 26 are substantially connected to each other. The center is bent so that the front end portion of the front portion 25 faces upward and is displaced downward as a whole.

  In addition, due to the downward bending of the bending promoting portions 24, 24, the side frames 14, 14 do not come into contact with and interfere with the lower surfaces of the front side frames 2, 2, and the front side frames 2, 2 are No major damage. Thereby, even if the side frames 14 and 14 are bent and the distance between the front end support portions 18 and 18 of the side frames 14 and 14 and the intermediate support portions 21 and 21 is shortened, the front end support portions 18 and 18. Since the front side frames 2 and 2 to which the intermediate support portions 21 and 21 are connected and supported are not damaged as described above, the front side frames 2 and 2 continue to maintain a high rigidity in the front-rear direction. Therefore, at the initial stage of the collision, when the side frames 14 and 14 are bent, the front side frames 2 and 2 are not deformed at a stretch and damaged, and the front side frames 2 and 2 efficiently absorb the impact energy. Therefore, the impact load can be greatly reduced with a simple configuration.

  In this case, as described above, the collision load is reduced to some extent by the crash pipes 22 and 22 and the reinforcement 23 and is input to the side frames 14 and 14, so that the impact energy is absorbed by the high rigidity of the front side frames 2 and 2. Part of the collision load can be transmitted to the front side frames 2 and 2 so as to facilitate the performance, and the impact energy absorption can be improved as a whole.

  Further, in the present embodiment, the plate thickness and material of the front portions 25, 25 and the rear portions 26, 26 of the bending promoting portions 24, 24 are adjusted, so that the front portions 25, 25 are moved in the vertical direction in the front-rear direction. The strength against bending is greater than the strength of the rear portions 26 and 26.

  Thereby, since the damage of the front parts 25 and 25 can be suppressed when the bending promotion parts 24 and 24 are bent, it can be surely bent downward.

  Further, the rear portions 26 and 26 of the side frames 14 and 14 are formed such that the width of the rear front portions 26c and 26c is smaller than the width of the rear rear portions 26d and 26d. Thus, when the bending promoting portions 24, 24 are bent downward, the vicinity of the support structure between the side frames 14, 14 and the intermediate support portions 21, 21 is greatly deformed, and the side frames 14, 14 and the intermediate support are supported. A decrease in the strength of connection with the portions 21 and 21 is suppressed, and the bending promoting portions 24 and 24 can be reliably bent.

As described above, the impact energy absorption at the front portion of the vehicle can be reliably improved.
(Detailed structure of the front end support portions 18, 18 of the side frames 14, 14)
Next, the front end support portions 18 of the side frames 14 will be described with reference to FIGS.

  As shown in FIG. 4, a crash tube rear end wall 31 is fixed to the flange portion 22 a of the rear end portion of the crash tube 22 so as to cover the rear end opening of the crash tube 22.

  Further, at the front end portion of the side frame 14, the upper panel 25a and the lower panel 25b of the front portion 25 are overlapped and formed by flange coupling as will be described later. In this case, the plate thickness of the upper panel 25a Is thicker than the thickness of the lower panel 25b.

  An intermediate portion in the vehicle width direction at the front end portion of the upper panel 25a is fixed to the rear end wall 31 of the crush tube by welding. In addition, the front end portion of the lower panel 25b is formed so that the intermediate portion in the vehicle width direction protrudes upward as it goes forward, and the front end portion crashes in a state where it protrudes in this way. It is fixed to the tube rear end wall 31 by welding.

  As shown in FIG. 5, on the vehicle outer side of the front end portion of the side frame 14, the vehicle width direction end portion on the upper surface of the side frame 14 of the upper panel 25a is substantially the lower surface of the side frame 14 as it moves to the vehicle outer side. The side frame 14 extends substantially horizontally toward the outer side in the vehicle width direction near the height of the substantially lower surface of the side frame 14.

  Further, on the vehicle outer side, the vehicle width direction end portion of the raised portion in the vehicle width direction intermediate portion of the lower panel 25b extends along the upper panel 25a extending so as to be directed downward. The frame 14 extends downward to reach the height of the substantially lower surface of the frame 14. At this time, the lower panel 25b overlaps the upper panel 25a. The lower panel 25 b extends substantially horizontally toward the outer side in the vehicle width direction of the side frame 14 in the vicinity of the height of the substantially lower surface of the side frame 14. In this way, on the vehicle outer side of the front end portion of the side frame 14, the upper panel 25a and the lower panel 25b that are overlapped with each other are joined to extend outward in the vehicle longitudinal direction. A substantially flat flange portion 32 is formed.

  Similarly, also on the vehicle inner side of the front end portion of the side frame 14, the vehicle width direction end portion of the upper surface of the side frame 14 of the upper panel 25a is substantially the height of the lower surface of the side frame 14 as it moves toward the vehicle inner side. The side frame 14 extends substantially horizontally toward the outer side in the vehicle width direction of the side frame 14 near the height of the substantially lower surface of the side frame 14. However, the inclination degree directed toward the lower side of the upper panel 25a is moderate as compared with the vehicle outer side.

  Similarly, with respect to the lower panel 25b, on the vehicle inward side of the front end portion of the side frame 14, the vehicle width direction end portion of the raised portion of the lower panel 25b extends downward. Along the gently sloping upper panel 25a, the side frame 14 extends downward to reach the height of the substantially lower surface. The lower panel 25b extends downward so as to overlap the upper panel 25a, and is substantially horizontal toward the inner side in the vehicle width direction of the side frame 14 near the height of the substantially lower surface of the side frame 14. It is extended. In this way, the substantially flat flange part 33 extended in the vehicle inner side over the vehicle front-back direction is formed by joining the upper panel 25a and the lower panel 25b which overlap each other also in the vehicle inner side. Is done.

The upper panel 25a and the lower panel 25b are joined to each other at the flange portion 32 and the flange portion 33 by welding. (Flange connection)
On the inner side, the upper surface and the lower surface of the end portion of the front cross member 15 are joined to the vicinity of the upper surface of the side frame 14 and the flange portion 33, respectively.

With such a configuration, in the cross section in the vehicle width direction, a substantially rectangular closed cross section O surrounded by the upper portion of the upper panel 25a and the upper surface of the lower panel 25b, and both ends of the closed cross section O in the vehicle width direction The lower side wall surfaces P1 and P2 are formed extending from the lower side to the lower surface of the crash tube 22 to the vicinity of the height of the lower surface of the upper side panel 25a where the lower side portion of the upper panel 25a and the side wall of the lower panel 25b overlap. It will be. (See Figure 5)
In FIG. 5, a two-dot broken line M indicates the outline of the rear end portion of the crush tube 22 immediately before the flange portion 22a.

  According to this, the heights of the flange portion 32 and the flange portion 33 and the height of the lower surface of the rear end portion of the crash tube 22 are located close to each other so as to be substantially the same height.

  Further, the outer side wall of the side frame 14 formed by extending the upper panel 25a downward on the vehicle outer side from the side frame 14 is the vehicle outer side wall of the crash tube 22 when viewed from the vehicle front-rear direction. Are joined to the rear end wall 31 of the crush tube.

  Further, the inner side wall of the side frame 14 formed by gently extending the upper panel downward on the vehicle inner side from the side frame 14 is directed further forward from the vehicle front-rear direction. Accordingly, the side frame 14 is joined to the rear end wall 31 of the crash tube in a state where the cross-sectional shape in the vehicle width direction becomes larger so as to approach a quadrangle and is positioned so as to substantially overlap the vehicle inner side wall of the crash tube 22. ing.

  A portion surrounded by the flange portion 32 and the flange portion 33 where the lower panel 25b protrudes upward is formed with a recessed portion 34 having a recessed shape when viewed from below.

  An inner and outer cylindrical rubber bushing 35 is installed as the front end support portion 18 so as to penetrate the recess 34 formed by the lower panel 25b and the upper panel 25a positioned above the recess 34.

  Next, the rubber bush 35 will be described in detail. The rubber bush 35 is a steel outer joint that is joined to the upper panel 25a and the lower panel 25b so as to penetrate from the upper surface of the side frame 14 to the recess 34. A cylindrical portion 36 and an inner cylindrical portion 37 having a smaller diameter are provided concentrically. In addition, the upper side of both the outer cylinder part 36 and the inner cylinder part 37 extends from the upper surface of the side frame 14, and the extended upper end part extends substantially horizontally toward the outer circumferential direction. An upper end outer peripheral edge 36a and an upper end outer peripheral edge 37a are formed. In this case, the upper end outer peripheral edge portion 36a of the outer cylindrical portion 36 is positioned below the upper end outer peripheral edge portion 37a of the inner cylindrical portion 37.

  The cylindrical rubber 38 is fitted into a space surrounded by the outer cylinder portion 36 and the inner cylinder portion 37. This rubber 38 is on the upper side, and the upper end of the rubber 38 extending to the outer peripheral side in the space surrounded by the upper outer periphery 37a of the inner cylinder 37 and the upper outer periphery 36a of the outer cylinder 36 described above. It extends so that the outer periphery part 38a may be inserted.

  On the other hand, the lower end side of the rubber 38 is configured to be positioned at a substantially intermediate position between the height of the upper surface of the side frame 14 and the height of the recessed portion 34.

A bolt 39 that is fixed to the front end 2a and extends downward is extended from the front end 2a of the front side frame 2 to the rubber bush 35, and the inside of the inner cylinder portion 37 of the rubber bush 35 is extended. The bolt 39 is inserted into the bolt 39. Then, in a state where the lower end of the front end portion 2 a and the upper end portion of the inner cylinder portion 37 are in contact, the O-ring 40 is in contact with the lower end portions of the outer cylinder portion 36 and the inner cylinder portion 37, respectively. A nut 41 is fastened to the lower side.
(Operations and effects in the structure of the front end support portion 18 of the side frame 14)
The structure of the front end support portion 18 as described above provides the following operations and effects.

  In other words, the vehicle is usually required to be light in weight for the purpose of improving fuel efficiency, and this is not an exception for the rubber bush 35 as a positional component.

  In the present embodiment, the side frame 14 needs to be firmly fixed so as to resist a collision load from the front side. However, the side frame 14 itself is firmly fixed via the rubber bush 35 by the intermediate support portion 21 and the rear end support portion 19, and is attached to the front side frame 2 via the front end support portion 18 of the side frame 14. There is little influence of input vibration and load. Further, only the lightweight crash tube 22 or the like is provided at the front end portion of the side frame 14, and this portion is relatively lightweight. For these reasons, it is not necessary to support the side frame 14 on the front side frame 2 by the front end support 18. Therefore, in this embodiment, further weight reduction to the rubber bush 35 is achieved.

  In order to reduce the weight of the rubber bush 35, the rubber bush 35, that is, the outer cylindrical portion 36, the inner cylindrical portion 37, and the rubber 38 may be shortened in the vertical direction in consideration of downsizing, that is, vibration reduction. Furthermore, the outer cylinder part 36, the inner cylinder part 37, and the rubber 38 are shortened, and the length of the rubber 38 alone is further shortened, whereby the weight can be further reduced.

  However, when the rubber bush 35 is shortened in this way, a configuration in which the lower panel 25b immediately below the rubber bush 35 is not normally raised and the recess 34 is not provided as in the present embodiment is conceivable. . In this case, in order to support the lower end part of the outer cylinder part 36 of the rubber bush 35, it is substantially the same as the raised lower panel 25b in the present embodiment at the position of the approximate center between the upper panel 25a and the lower panel 25b. It is necessary to newly provide a horizontal reinforcing member separately from the lower panel 25b. However, the installation of such a reinforcing member causes a problem that productivity is deteriorated.

  On the other hand, in the present embodiment, the front end portion of the side frame 14 and the vicinity thereof have a substantially rectangular closed cross section O where the rubber bush 35 is installed in the vehicle width direction cross section, and both ends of the closed cross section in the vehicle width direction. The lower side wall surfaces P1 and P2 extending from the portion to the vicinity of the height where the lower surface of the shock absorbing member is located are formed and extended in the vehicle front-rear direction. Specifically, on the lower side of the rubber bush 35, the lower panel 25b was raised to form a recess 34. Accordingly, the rubber bush 35 can be easily shortened without separately providing a reinforcing member. Moreover, the front end portion of the side frame 14 and the vicinity thereof are reduced in rigidity due to the formation of the recessed portion 34 for shortening the rubber bush 35 by the substantially rectangular closed cross section O and the lower side wall surfaces P1 and P2. Accordingly, the support rigidity of the crash tube 22 can be improved, and the impact energy absorption by the crash tube 22 can be increased.

  Further, since the support rigidity to the vehicle body frame by the front end support portion 18 is also improved, the collision load is positively transmitted to the front side frames 2 and 2 at the time of a vehicle collision, and the above-described bending promotion portion 24 and the like are used. The collision load by the front subframe 17 can be further reduced.

  Moreover, since the flange part 32 and the flange part 33 are provided in the both ends of the vehicle width direction at the height of the substantially lower surface of the side frame 14 and close to this lower surface, it is just behind the crash pipe 22. The left and right flange portions 32 and 33 can improve the rigidity in the front-rear direction in particular for the portion requiring high rigidity in the front-rear direction of the vehicle. Will not be reduced.

  In the present embodiment, the upper panel 25a is thicker than the lower panel 25b. Further, the upper panel 25a is positioned in the vicinity where the recess 34 of the side frame 14 is formed. The side panel 25b is provided so as to cover substantially the whole from above. Thus, the upper panel 25a forms the side wall surface of the side frame 14, and overlaps the lower panel 25b at the lower part thereof. With such a configuration, the depression 34 reduces the cross-sectional area in the vehicle width direction of the side frame 14 and reduces the rigidity by the thicker upper panel 25a forming the side wall surface of the side frame. And high rigidity can be maintained as a whole.

  In particular, in the present embodiment, the upper panel 25a extends to the lower surface of the side frame 14 in a state where it overlaps the lower panel 25b at the lower portion of the side wall surface, and then extends toward the vehicle width direction with the upper panel 25a. Since the flange portions 32 and 33 overlapped with the lower panel 25b are formed, higher rigidity can be maintained.

  Moreover, since the operation of fastening the nut 41 to the bolt 39 can be performed by the relatively large recess portion 34 by the recess portion 34, the fastening workability can be improved.

In the present invention, it is not always necessary to increase the plate thickness of the upper panel 25a. The plate thickness of the upper panel 25a and the lower panel 25b is substantially the same, or the plate thickness of the lower panel 25b is thicker. It doesn't matter.
(Around the mounting structure of the rear end support 19 of the side frame 14)
Next, the periphery of the attachment structure of the rear end portions of the side frames 14, 14 will be described.

  As shown in FIG. 1, mounting portions 42, 42 are formed adjacent to the floor frames 3, 3 on the floor panel 8 on the vehicle inner side at the front ends of the floor frames 3, 3. The rear end support portions 19 and 19 are connected and supported by the attachment portions 42 and 42 via rubber bushes 43 and 43.

The lower surfaces of the mounting portions 42, 42 (however, the road surface side is lower) are formed in the vicinity of the rear end support portions 19, 19 so as to be higher than the lower surfaces of the floor frames 3, 3 that are inclined downward toward the rear. . (See Figs. 6 and 7)
In addition, in the attachment portions 42 and 42, the rear end support portions 19 and 19 are projected immediately below the portion supporting the rear end support portions 19 and 19, at a position lower than the lower surfaces of the attachment portions 42 and 42. Stopper portions 42a and 42a (protrusions) are formed, and the lower surfaces of the attachment portions 42 and 42 extend from the attachment portions 42 and 42 to the rear side on the vehicle inward side of the stopper portions 42a and 42a. Branch frames 44, 44 are formed at substantially the same height. A portion branched from the floor frames 3 and 3 at the front ends of the branch frames 44 and 44 (including the attachment portions 42 and 42 in the present embodiment) is referred to as branch portions 44a and 44a.

Further, the floor panels 8 that are one step higher than the lower surfaces of the branch frames 44 and 44 are positioned at both ends in the vehicle width direction of the rear portions of the branch frames 44 and 44. The stopper portions 42a and 42a are also adjacent to the vehicle inner side of the floor frames 3 and 3, but the entire lower surface of the stopper portions 42a and 42a or at least the rear portion including at least the rear portion is inclined downward toward the rear. It is formed so as to be higher than the lower surfaces of the floor frames 3 and 3 to be performed. (See Figs. 7 and 8)
A dash cross member 45 is provided at the front end side of the mounting portions 42 and 42 on the vehicle inner side of the portion where the rear end support portions 19 and 19 are located so as to bridge the left and right mounting portions 42 and 42. Along the vehicle width direction. The lower surface of the dash cross member 45 is formed one step higher than the lower surface of the attachment portions 42, 42 and one step lower than the surrounding floor panel 8 in the portion adjacent to the attachment portions 42, 42.

  Cover portions 46, 46 are provided to cover the stopper portions 42 a, 42 a, the portions of the floor frames 3, 3 adjacent to the stopper portions 42 a, 42 a, and the lower side of the rear end support portions 19, 19. ing. Bolt holes 47 and 47 are formed in the stopper portions 42a and 42a, and bolt holes 48 and 48 are formed in the floor frames 3 and 3, and these bolt holes are provided via cover portions 46 and 46, respectively. The cover portions 46 are fixed by fastening the bolts. Further, the cover portions 46, 46 support the rear end support portions 19, 19 via the rubber bushes 43, 43, thereby preventing the rear end of the side frame 14 from falling.

  Next, the attachment portion 42, the stopper portion 12a, and their peripheral structures will be described in detail with reference to FIGS.

  As shown in FIG. 6, in the vicinity of the rear end support portion 19, the floor panel 8 is joined with a concave floor frame panel 3 a having a rectangular cross section when viewed from the front-rear direction of the vehicle and opened upward. A reinforcement 3b that connects the side surfaces of the floor frame panel 3a in the front-rear direction is provided at an intermediate portion in the direction. Further, a concave connection frame panel 13a having a rectangular cross section forming the connection frame 13 and opening upward is joined to the lower surface of the floor frame 3 so as to cover the lower surface of the floor frame panel 3a. The reinforcement of the frame 3 and the connection between the floor frame 3 and the connection frame 13 are achieved. In the vicinity of the rear end support portion 19, the floor frame 3 is inclined downward toward the rear side. According to this figure, the lower surface of the connection frame 13 is the lower surface of the floor frame 3. Is located lower than.

  The vehicle outer side end portion of the dash cross end panel 45a is joined to the vertical center portion of the vehicle inner side surface of the floor frame panel 3a, and at the lower side of the inner side surface of the floor frame panel 3a. The vehicle outer side end portion of the attachment portion panel 42b forming the attachment portion 42 is joined to a position slightly higher than the lower surface of the floor frame panel 3a.

  A dash cross member panel 45b forming the dash cross member 45 is joined to the floor panel 8 toward the center of the vehicle on the vehicle inward side of the dash cross end panel 45a. At this time, it joins so that the inner side edge part of the dash cross edge part panel 45a and the inner edge part of the attaching part panel 42b may overlap with the lower surface of the vehicle outer side edge part of the dash cloth member panel 45b. In this way, the end portions of the mounting portion 42 and the dash cross member 45 are reinforced.

  A base portion of a bolt 49 is fixed to the dash cross end panel 45a so as to face downward, and the bolt 49 passes through the mounting portion panel 42b and the cover portion 46 below and extends further downward. Yes. The rubber bushing 43 of the rear end support portion 19 of the side frame 14 is an inner and outer cylinder type, and a ring shape is provided between an outer cylinder 43a (see FIG. 7) joined to the rear end of the side frame 14 and the inner cylinder 43b. The upper rubber 43c and the lower rubber 43d are inserted, the upper end portion of the upper rubber 43a is in contact with the lower surface of the mounting portion panel 42b, and the lower end portion of the lower rubber 43d is in contact with the upper surface of the cover portion 46. ing.

  A nut 50 is fastened to the bolt 49 penetrating the cover portion 46, whereby the rubber bush 43 is sandwiched between the cover portion 46 and the mounting portion panel 42b via the upper rubber 43c and the lower rubber 43d. Therefore, the rear end portion of the side frame 14 is fixed to the attachment portion 42 so as to reduce vibration.

  FIG. 7 is a view of the periphery of the rear end support portion 19 viewed from the vehicle width direction. According to this, the floor panel 8 is inclined downward from the front side toward the rear side. Along this, the lower surface of the floor frame 3 (the two-dot broken line N in FIG. 7) is similarly inclined at a position spaced apart from the floor panel 8 by a predetermined distance.

  A dash cross end panel 45a is joined to the inclined portion of the floor panel 8, and a dash cross end extension 45c extends from the rear side of the dash cross end panel 45a. The end portion of the member 45 is reinforced.

  The front end of the attachment portion panel 42b is joined to the front end of the dash cross end portion panel 45a, and then protrudes downward to form the attachment portion 42 as it goes rearward. Furthermore, it protrudes further downward from the rear end of the lower surface of the mounting portion 42, thereby forming a stopper portion 42a. The rear end of the stopper portion 42a extends upward to extend to the floor panel 8. It is joined to.

  Thus, the attachment part 42 and the stopper part 42a are formed by the attachment part panel 42b, and these connection rigidity is improved.

  The cover portion 46 is inclined upward as it goes rearward from the vicinity of the rear end support portion 19 and is in contact with the lower surface of the mounting portion panel 42b forming the stopper portion 42a. The bolt 51 is fastened to the bolt hole 47 via the portion 46, whereby the cover portion 46 and the lower surface of the stopper portion 42a are screwed and fixed.

  As described above, the rear end support portion 19, that is, the upper portion of the rubber bush 43 is connected to the stopper portion 42a by the continuous mounting portion panel 42b extending downward toward the rear, and the lower portion of the rubber bush 43 is Since it is connected to the stopper portion 42a by the continuous cover portion 46 extending upward as it goes rearward, the connection rigidity between the rear end portion of the side frame 14 and the stopper portion 42a can be enhanced.

  FIG. 8 is a view of the vicinity of the fastening position of the bolt 51 as seen from the vehicle front-rear direction.

  According to this, the floor frame 3 is formed by the floor frame panel 3a and the reinforcement 3b, and the connection frame 13 is substantially the same as FIG. 6 in that it is formed by the connection frame 13a.

  A vehicle outer side end portion of the mounting portion panel 42b that forms the stopper portion 42a is slightly below the lower surface of the floor frame panel 3 at a lower portion of the vehicle inner side surface of the floor frame panel 3a. It joins so that the substantially half in the vehicle width direction of a lower surface may be covered.

  A branch frame panel 44a that forms a branch frame 44 extending rearward from the mounting portion 42 is fixed to the floor panel 8 that is spaced a predetermined distance from the floor frame 3 toward the vehicle inner side in the vehicle width direction. Yes.

  In the mounting portion panel 42b forming the stopper portion 42a, the vehicle inner side end portion in the vehicle width direction is joined so as to cover the lower surface of the branch frame panel 44a.

With such a configuration, the stopper portion 42 a is connected to both the floor frame 3 and the branch frame 44 with high rigidity.
(Operation and effects in the mounting structure of the rear end support portion 19 of the side frame 14 and its peripheral structure)
With the configuration as described above, the stopper portion 42a is arranged immediately rearward of the rear end support portion 19 of the side frame 14, so that a large collision load is applied from the front to the rear with respect to the side frame 14 during a frontal collision of the vehicle. When the rear end support portion 19 is displaced rearward, the rear end support portion 19 comes into contact with the stopper portion 42a. At this time, since the stopper portion 42a is firmly connected by the branch frame 44 and the floor frame 3, the collision load can be distributed and transmitted to the branch frame 44 and the floor frame 3, and the collision energy can be distributed. Absorption is possible, and damage to the vehicle body such as the floor frame 3 can be suppressed.

  Further, the upper and lower portions of the rear end support portion 19 are connected to the stopper portion 42a with high rigidity via the attachment portion 42 and the cover portion 46, respectively. A large rearward impact load that acts can be efficiently transmitted to the stopper portion 42a. As a result, it is possible to further improve the dispersion and absorption of the collision energy by the branch frame 44 and the floor frame 3 as described above.

  In addition, since the stopper portion 42a disposed at a position slightly higher than the floor frame 3 supports the lower portion of the rear end support portion 19 via the cover portion 46, the support structure below the rear end support portion 19 is It is arranged below the floor frame 3 so as to prevent the distance between the lower surface of the vehicle body and the road surface from being shortened.

  Further, since the attachment portion 42 is also connected to the end portion of the dash cross member 43 formed to have high rigidity, the collision load acting on the side frame 14 at the time of a frontal collision of the vehicle is applied to the dash cross member 43, and Through this, it is also transmitted to the floor frame 3 on the opposite side in the vehicle width direction, and it becomes possible to further improve the dispersion and absorption of the collision energy.

  Further, since the connection frame 13 is formed adjacent to the floor frame 3 on the vehicle outer side and the rear side from the mounting portion 42 of the floor frame 3, it acts on the side frame 14 at the time of a vehicle front collision. The collision load can be transmitted to the connection frame 13 and the side sill 12 via the connection frame 13, thereby further improving the dispersion and absorption of the collision energy.

The figure which looked at the front sub-frame 17 and the vehicle body frame 1 etc. which concern on this embodiment from the lower surface of the vehicle. AA sectional drawing of FIG. The perspective view which looked at only the front side frame 17 from diagonally forward. BB sectional drawing of FIG. CC sectional drawing of FIG. DD sectional drawing of FIG. EE sectional drawing of FIG. FF sectional drawing of FIG.

1: Body frame 2: Front side frame 14: Side frame 17: Front subframe 18: Front end support portion 19: Rear end support portion 21: Intermediate support portion 22: Crash tube (impact absorbing member)
23: Reinforcement 24: Bending promotion part 25: Front part 25a: Upper panel (upper member)
25b: Lower panel (lower member)
26: Back part 26a: Front part front side part (width reduction part)
26b: front part rear side part (width expansion part)
27: Front side lower arm support part 28: Rear side lower arm support part 32, 33: Flange part 34: Recess part 35: Rubber bush 42: Mounting part 42a: Stopper part 43: Rubber bush 44: Branch frame 45: Dash cross member 46 : Cover portion O: Closed cross section P1: Lower side wall surface P2: Lower side wall surface

Claims (4)

A side that is extended in the vehicle longitudinal direction on the lower side of the vehicle body frame and that is supported by the vehicle body frame by a front end support portion that is located in the vicinity of the front end portion and a support portion at a predetermined position rearward of the front end support portion In a front subframe of an automobile configured by a frame and an impact absorbing member that is fixed to the front end and extends to the front side of the vehicle so as to absorb an impact at the time of a collision,
The front end support portion has a cylindrical shape and is arranged so that the axial direction is substantially along the vertical direction, and the length in the axial direction is shorter than the vertical length of the shock absorbing portion. Is provided,
The front end portion of the side frame and the vicinity thereof are, in a cross section in the vehicle width direction, a substantially rectangular closed cross section to which the inner and outer cylindrical rubber bushes are fixed, and the shock absorbing member from both ends of the closed cross section in the vehicle width direction. And a lower side wall surface extending to a height near where the lower surface of the vehicle is located, and the closed cross section and the lower side wall surface are extended in the vehicle front-rear direction. Front subframe.   The front end portion of the side frame and the vicinity thereof are, in the cross section in the vehicle width direction, an upper member and a lower member whose intermediate portions are raised upward with respect to the both ends in the vehicle width direction, and the closed cross section is The flange portion is formed by overlapping in the vertical direction so as to be formed, and by this overlapping, a flange portion is formed in the vehicle front-rear direction in the vicinity of the height where the lower surface of the shock absorbing member is located. The front subframe of the automobile according to claim 1. 3. The front subframe of an automobile according to claim 2, wherein a thickness of the upper member is greater than a thickness of the lower member.
flame. 2. The front sub-frame of an automobile according to claim 1, wherein a flange portion directed to the outer side of the side frame is formed from the lower end of the lower side wall surface in the vehicle front-rear direction.

Images