JP2018069892A - Sub-frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve prevention of adjacent vehicle components from being damaged while improving absorption performance of impact energy when a collision occurs.SOLUTION: A sub-frame, constituting a vehicle body front part, includes: a front-side cross member part extending in vehicle width direction; a rear-side cross member part extending in vehicle width direction, and spaced from the front-side cross member part rearward in vehicle longitudinal direction; right and left lateral parts each extending rearward in vehicle longitudinal direction from both end parts in vehicle width direction of the front-side cross member part; right and left inclined parts extending, being inclined to the central side in vehicle width direction rearward in vehicle longitudinal direction from each rear part of the right and left lateral parts and connecting the right and left lateral parts with the rear-side cross member part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a subframe that constitutes a front portion of a vehicle body.

  In an offset collision such as a narrow offset collision or a small overlap collision, a load inward in the vehicle width direction is generated at the front of the vehicle body. As a countermeasure, a structure in which an inclined portion is included in a vehicle body constituting member has been proposed. For example, Patent Document 1 discloses a structure in which a triangular subframe is pivotally attached to a cross member member so as to suppress the rotational movement of the vehicle body at the time of a collision. Patent Document 2 discloses a structure provided with V-shaped and A-shaped braces.

Japanese Patent No. 3801748 JP 2014-104898 A

  In the configuration of Patent Document 1, since the subframe and the cross member member are pivotally attached to each other, there is a possibility that load transmission from the subframe to the cross member member does not work strongly. There is room for improvement in terms of absorbability of impact energy. In general, a power plant such as an engine is arranged in the front part of the vehicle body. When a V-shaped inclined part is provided as in Patent Document 1 and Patent Document 2, such a vehicle component part is provided between the inclined parts. Some may be located. The vehicle component and the inclined portion that are sandwiched between the inclined portions at the time of collision interfere with each other and the vehicle component is damaged.

  An object of the present invention is to prevent damage to adjacent vehicle components while improving impact energy absorption performance at the time of a collision.

According to the present invention, a sub-frame that constitutes a front part of a vehicle body,
A front cross member extending in the vehicle width direction;
A rear cross member extending in the vehicle width direction and spaced rearward from the front cross member in the vehicle longitudinal direction; and
Left and right side portions respectively extending rearward in the vehicle front-rear direction from both ends in the vehicle width direction of the front cross member portion;
Left and right inclined portions extending from the rear portions of the left and right side portions to the rear in the vehicle front-rear direction and inclined toward the center in the vehicle width direction, and connecting the left and right side portions and the rear cross member portion; ,including,
A subframe characterized by this is provided.

  ADVANTAGE OF THE INVENTION According to this invention, damage to the adjacent vehicle component can be prevented, improving the absorption performance of the impact energy at the time of a collision.

The perspective view of the sub-frame which concerns on one Embodiment of this invention. (A)-(D) are sectional drawings which follow the II line, II-II line, III-III line, and IV-IV line of FIG. The top view of the vehicle body front part structure to which the sub-frame of FIG. 1 is applied. The side view of the vehicle body front part structure of FIG. Explanatory drawing explaining the behavior of the sub-frame of FIG. 1 at the time of an offset collision.

  FIG. 1 is a perspective view of a subframe 1 according to an embodiment of the present invention, and FIGS. 2 (A) to 2 (D) are II line, II-II line, III-III line, IV of FIG. It is sectional drawing which follows the -IV line. In FIG. 1, the front-rear direction and the vehicle width direction indicate the vehicle front-rear direction (full length direction) and the vehicle width direction when the subframe 1 is mounted on a vehicle, and the left and right are based on the vehicle forward direction. It is said. In this embodiment, the vehicle is a four-wheeled vehicle. The subframe 1 includes a front cross member portion 2, a rear cross member portion 3, left and right side portions 4, and left and right inclined portions 5.

  The front cross member 2 is a member extending in the vehicle width direction. In the case of this embodiment, the front cross member part 2 is a pipe member such as a steel pipe, and has a circular cross section as shown in FIG. In the case of this embodiment, the cross member portion 2 is slightly curved from the center portion to the left and right end portions 21.

  The rear cross member portion 3 is a member extending in the vehicle width direction, and is separated from the front cross member portion 2 rearward in the vehicle front-rear direction. In the case of the present embodiment, the rear cross member portion 3 includes an extending portion 31 extending in the vehicle width direction and left and right widened portions 32 integrally provided at both end portions 31c of the extending portion 31 in the vehicle width direction. Including. The widened portion 32 is wider in the front-rear direction than the extended portion 31.

  The extending portion 31 includes a central portion 31a, an end portion 31c, and left and right connecting portions 32b between the central portion 31a and the end portion 31c when viewed in the vehicle width direction. The connection part 32b is a part to which the rear end of the inclined part 5 is connected.

  The widened portion 32 includes a front portion 32a and a rear portion 32b when viewed in the front-rear direction, and has a Y-shaped outer shape in plan view. Mounting portions 32a 'and 32b' for supporting the subframe 1 on the vehicle body are provided on the front portion 32a and the rear portion 32b, respectively. In the present embodiment, the attachment portions 32a 'and 32b' are shaft members extending upward.

  An attachment portion 33 to which the lower arm 102 is attached is provided on the front portion 32a. The lower arm 102 constitutes a suspension device that supports the front wheels. In the attachment portion 33, the widened portion 32 opens to the outside in the vehicle width direction, and the end portion of the lower arm 102 is supported so as to be rotatable around an axis in the front-rear direction. A mounting portion 6 is provided on the right widened portion 32. The attachment portion 6 is a bracket to which the torque rod is attached, and is fixed to the widened portion 32.

  Each of the left and right side portions 4 extends rearward in the front-rear direction from the end portions 21 on both sides of the front cross member portion 2. The side portion 4 includes a front portion 41 and a rear portion 42 when viewed in the front-rear direction, and has an outer shape in which the width in the vehicle width direction is widened forward in the front-rear direction in plan view. The end portion 21 of the front cross member portion 2 is inserted in the side portion 4, particularly in the front portion 41, in the vehicle width direction. The front part 41 and the rear part 41 are provided with attachment parts 41a and 42a for supporting the subframe 1 on the vehicle body, respectively. In the present embodiment, the attachment portions 41a and 42a are shaft members extending upward.

  The rear portion 42 is provided with an attachment portion 43 to which the lower arm 102 is attached. In the attachment portion 43, the rear portion 42 opens to the outside in the vehicle width direction, and the end portion of the lower arm 102 is supported so as to be rotatable around an axis in the vertical direction.

  Each of the left and right inclined parts 5 extends from the rear part 42 of the side part 4 to the rear side in the front-rear direction and inclines toward the center in the vehicle width direction, and connects the side part 4 and the rear cross member 3. Yes. The front end of the inclined portion 5 is separated from the end portion 21 of the front cross member portion 2 in the front-rear direction and connected to the rear portion 42, and the rear end of the inclined portion 5 is connected to the connection portion 31 b of the rear cross member portion 3. Has been. The rear ends of the left and right inclined portions 5 are separated in the vehicle width direction, and a central portion 31a is interposed between the rear ends. The front cross member 2, the left and right side portions 4, the left and right inclined portions 5, and the central portion 31 a of the rear cross member 3 form a pentagonal skeleton in plan view.

  In the case of the present embodiment, the rear cross member portion 3, the left and right side portions 4 and the left and right inclined portions 5 constitute a hollow body, and in particular, the upper divided body 11 and the lower divided body 12 are vertically arranged. It is integrally formed as a hollow monaca-structured hollow body. Each of the divided bodies 11 and 12 is integrally formed by, for example, pressing a steel plate. The front cross member part 2 which is a pipe member can obtain the configuration inserted into the side part 4 relatively easily by sandwiching each end part 21 between the upper divided body 11 and the lower divided body 12, In addition, the attachment portions 33 and 43 at each end of the lower arm 102 are also easily constructed between the upper divided body 11 and the lower divided body 12. Therefore, the subframe 1 provided with these can be manufactured relatively easily.

  2 (A) to 2 (C) are cross-sectional views taken along lines II, II-II, and III-III in FIG. 1, and show end portions 31c, connecting portions 31b, and centers in the cross-section in the front-rear direction. The cross-sectional shape of the part 31a is shown. The end portion 31c is separated from the inclined portion 5, and only the end portion 31c forms a closed cross section. The connecting portion 31b forms a closed cross section integral with the inclined portion 5. The central part 31a also forms a closed section only by the central part 31a. Of the end portion 31c, the connecting portion 31b, and the central portion 31a, the connecting portion 31b forms a closed cross-section integrally with the inclined portion 5. As a result, the area is the largest, and the amount of deformation at the time of collision can be increased.

  Next, an example of mounting the subframe 1 on a vehicle will be described. FIG. 3 is a plan view of the vehicle body front part structure 100 to which the subframe 1 is applied. The vehicle body front part structure 100 constitutes the front part of the four-wheeled vehicle. FIG. 4 is a side view of the vehicle body front part structure 100 and shows a support for the subframe 1 by the front side frame 101. The vehicle body front structure 100 includes a pair of front side frames 101 spaced in the vehicle width direction. Each front side frame 101 extends in the front-rear direction.

  A power plant P is disposed between the pair of front side frames 101, and the subframe 1 is disposed below the power plant P. The power plant P includes, for example, an engine and a transmission. The power plant P is supported by the front side frame 101, for example. In the case of the present embodiment, the power plant P is exemplified as a vehicle component disposed between the pair of front side frames 101, but other vehicle components are disposed between the pair of front side frames 101 according to the layout of the vehicle. It is also possible to adopt a configuration that does this.

  One end of the torque rod 103 is attached to the attachment portion 6 of the subframe 1, and the other end of the torque rod 103 is attached to the power plant P. By connecting the subframe 1 and the power plant P via the torque rod 103, vibrations generated by the power plant P can be reduced, and quietness can be improved.

  The subframe 1 is connected to and supported by the front side frame 101 at the attachment portions 41a, 41b, 32a 'and 32b'. The attachment portions 41a, 41b, 32a 'and the front side frame 101 are connected to each other via a support member 104 extending in the vertical direction. In the present embodiment, the mounting portion 41 a and the end portion of the lower arm 102 are supported at the rear portion 42 of the side portion 4, and the mounting portion 32 a ′ and the lower arm 102 are provided at the front portion 32 a of the widened portion 32. Since the attachment portion 33 that supports the end portion is provided, the attachment portion 41a and the attachment portion 43 are close to each other, and the attachment portion 32a ′ and the attachment portion 33 are close to each other. Therefore, the vertical input of the lower arm 102 is supported by the front side frame 101 via the support member 104, and the support rigidity of the lower arm 102 can be improved.

  The front end portion 101a of the front side frame 101 widens in the vehicle width direction toward the front in the front-rear direction when seen in a plan view, so that the side portion 4 also moves toward the front in the front-rear direction when seen in a plan view. The width in the width direction is widened. And the front-end part 101a and the front part 41 are connected in the attachment part 41a. Thereby, even in the small overlap collision, the collision load is easily input to the subframe 1.

  Next, the behavior of the subframe 1 in the vehicle body front structure 100 when an offset collision occurs will be described with reference to FIG. Assume that a collision load L1 is input to the subframe 1 due to an offset collision. In the example of FIG. 5, it is assumed that a load L <b> 1 is input in the vicinity of the left end 21 of the front cross member 2.

  When the load L1 is input, the left end 21 of the front cross member 2 is pressed backward as indicated by a broken line. In the case of this embodiment, the front cross member 2 is a pipe member having a relatively high rigidity, and its end 21 is inserted into the side 4, so that the center of the side 4 in the front-rear direction, etc. Is crushed by rearward displacement of the end 21 of the front cross member 2 (deformation C1). The impact energy of the load L1 is absorbed by the deformation C1. In addition, the load L1 is easily transmitted to the left inclined portion 5, and the axial force F acting on the inclined portion 5 (the load transmitted in the longitudinal direction of the inclined portion 5) can be increased.

  In the case of the present embodiment, each inclined portion 5 is rigidly coupled to the rear cross member portion 3, and the connecting portion between each inclined portion 5 and the rear cross member portion 3 due to the deformation C <b> 1 of the side portion 4. It is set as the structure which the rotation displacement of the inclination part 5 centering on this does not produce easily. In the case of the configuration of the vehicle body front part structure 100 according to the present embodiment, the lower part P ′ of the power plant P has a layout located between the left and right inclined parts 5 as shown in FIG. 5. By the input of the load L1, there is a possibility of interference between the right inclined part 5 and the lower part P ′ at the position indicated by the part S. However, as described above, the rotational displacement of the inclined part 5 is difficult to occur. Further, it is possible to avoid the damage by avoiding the interference between the right inclined portion 5 and the lower portion P ′.

  The axial force F is transmitted to the rear cross member portion 3 at the connecting portion 31b, and a shearing force F 'is applied to the rear cross member portion 3 to deform its cross section. Thereby, impact energy can be absorbed. In particular, as shown in FIGS. 2A to 2C, the connection portion 31b has a closed cross-sectional area larger than that of the central portion 31a and the end portion 31c, so that a larger deformation is caused around the connection portion 31b. The impact energy absorption performance can be further improved. The load L1 transmitted to the rear cross member portion 3 is input from the left and right widened portions 32 to the passenger compartment of the vehicle, but since the impact energy has already been absorbed, the loads FL and FR become small loads. The deformation of the vehicle body on the cabin side can be suppressed.

  A load L2 in FIG. 5 shows an example of a load in a small overlap collision. In the case of the present embodiment, the front end portion 101a and the side portion 4 of the front side frame 101 are widened in the vehicle width direction toward the front in the front-rear direction in plan view, so that a small overlap collision such as the load L2 occurs. The collision load can be easily input to the subframe 1 and the impact energy can be absorbed by the subframe 1 by the same behavior as in the case of the load L1.

<Summary of Embodiment>
1. The subframe of the above embodiment is
A subframe (e.g., 1) constituting the front of the vehicle body,
A front cross member portion (for example, 2) extending in the vehicle width direction,
A rear cross member portion extending in the vehicle width direction and spaced rearward from the front cross member portion in the longitudinal direction of the vehicle (for example, 3),
Left and right side portions (for example, 4) respectively extending rearward in the vehicle front-rear direction from both ends (for example, 21) in the vehicle width direction of the front cross member portion,
Left and right side parts extending from the rear parts (for example, 42) of the left and right side parts to the rear in the vehicle front-rear direction and inclined toward the center in the vehicle width direction and connecting the left and right side parts and the rear cross member part And an inclined portion (for example, 5).

  According to this configuration, in an offset collision, a shearing force can be applied to the rear cross member portion via the inclined portion to deform the cross section, thereby absorbing impact energy. Therefore, the impact energy absorption performance at the time of collision can be improved. In addition, the lateral portion is deformed in the front-rear direction, so that the inclining to the inside of the inclined portion can be suppressed, and interference with vehicle components located between the inclined portions can be reduced. Therefore, damage to adjacent vehicle components can be prevented.

2. In the subframe of the above embodiment,
The front cross member is composed of a pipe member;
The left and right side portions each include a front portion (for example, 41) into which the pipe member is inserted,
A lower arm (for example, 102) is attached to the rear portion.

  According to this structure, it is promoted that the side part is crushed in the front-rear direction by the pipe member, and the axial force of the inclined part is increased. Thereby, the deformation | transformation of the said rear side cross member part can be accelerated | stimulated, and the absorption capability of impact energy can further be improved.

3. In the subframe of the above embodiment,
The rear cross member portion and the left and right inclined portions are hollow bodies,
The rear cross member is
An extending portion (e.g., 31) having a closed cross section and extending in the vehicle width direction;
Left and right widened portions (for example, 32) that are provided at both ends of the extended portion in the vehicle width direction and have a width in the vehicle front-rear direction wider than the extended portion,
The extending portion is
A central portion (e.g. 31a) in the vehicle width direction,
Left and right connecting portions (for example, 32b), which are adjacent to the central portion and to which the left and right inclined portions are respectively connected,
Both end portions adjacent to the left and right widened portions (for example, 32c),
The central portion has a closed cross section at a cut surface in the vehicle front-rear direction,
The both end portions have a closed cross section at a cut surface in the vehicle front-rear direction,
The left and right connecting portions and the left and right inclined portions have an integral closed cross section in a cut surface in the vehicle front-rear direction,
The integral closed cross section has an area larger than the closed cross section of the central portion and the closed cross sections of the both end portions.

  According to this configuration, the amount of deformation can be increased at the left and right connection portions, and the impact energy absorption performance can be further improved.

4). In the subframe of the above embodiment,
The left and right side portions, the left and right inclined portions, and the rear cross member portion are formed by a hollow body formed by vertically coupling an upper divided body (for example, 11) and a lower divided body (for example, 121),
The pipe member is sandwiched between the upper divided body and the lower divided body.

  According to this configuration, the subframe including the pipe member and the lower arm can be manufactured relatively easily.

5. In the subframe of the above embodiment,
The rear cross member is
An extending part (for example, 31) extending in the vehicle width direction,
Left and right widened portions (for example, 32) that are provided at both ends of the extended portion in the vehicle width direction and have a width in the vehicle front-rear direction wider than the extended portion,
The left and right side parts are supported by a front side frame (e.g. 101),
The left and right widened portions include a front portion (for example, 32a) and a rear portion (for example, 32b) supported by the front side frame,
Lower arms are supported by the rear portions of the left and right side portions and the front portions of the left and right widened portions.

  According to this configuration, the upper and lower inputs of the lower arm can be supported by the front side frame, and the support rigidity of the lower arm can be improved.

6). In the subframe of the above embodiment,
The rear cross member is
An extending part (for example, 31) extending in the vehicle width direction,
Left and right widened portions (for example, 32) that are provided at both ends of the extended portion in the vehicle width direction and have a width in the vehicle front-rear direction wider than the extended portion,
A torque rod mounting portion (for example, 6) is provided on one of the left and right widened portions.

  According to this configuration, it is possible to improve the impact energy absorption performance at the time of collision while improving the quietness of the vehicle.

7). In the subframe of the above embodiment,
The left and right side parts are supported by a front side frame (e.g. 101),
The front end portion of the front side frame (e.g., 101a) is widened in the vehicle width direction toward the front in the vehicle front-rear direction,
The left and right side portions are widened in the vehicle width direction toward the front in the vehicle front-rear direction.

  According to this configuration, it is possible to improve impact energy absorption performance and prevent damage to adjacent vehicle components even in a small overlap collision.

8). The vehicle body front structure (e.g., 100) of the above embodiment is
A pair of front side frames (e.g. 101);
A sub-frame positioned below the power plant disposed between the pair of front side frames and supported between the pair of front side frames,
The subframe is:
A front cross member portion (for example, 2) extending in the vehicle width direction,
A rear cross member portion extending in the vehicle width direction and spaced rearward from the front cross member portion in the longitudinal direction of the vehicle (for example, 3),
Left and right side portions (for example, 4) respectively extending rearward in the vehicle front-rear direction from both ends (for example, 21) in the vehicle width direction of the front cross member portion,
Left and right side parts extending from the rear parts (for example, 42) of the left and right side parts to the rear in the vehicle front-rear direction and inclined toward the center in the vehicle width direction and connecting the left and right side parts and the rear cross member part And an inclined portion (for example, 5).

  According to this configuration, in an offset collision, a shearing force can be applied to the rear cross member portion via the inclined portion to deform the cross section, thereby absorbing impact energy. Therefore, the impact energy absorption performance at the time of collision can be improved. Moreover, the side part is deformed in the front-rear direction, so that it is possible to suppress the inward tilting of the inclined part and to reduce the interference between the inclined part and the lower part of the power plant. Therefore, damage to the power plant can be prevented.

1 Subframe, 2 Front cross member, 3 Rear cross member, 4 Side, 5 Inclined

Claims (7)

A sub-frame constituting the front of the vehicle body,
A front cross member extending in the vehicle width direction;
A rear cross member extending in the vehicle width direction and spaced rearward from the front cross member in the vehicle longitudinal direction; and
Left and right side portions respectively extending rearward in the vehicle front-rear direction from both ends in the vehicle width direction of the front cross member portion;
Left and right inclined portions extending from the rear portions of the left and right side portions to the rear in the vehicle front-rear direction and inclined toward the center in the vehicle width direction, and connecting the left and right side portions and the rear cross member portion; ,including,
A subframe characterized by that. The subframe according to claim 1, wherein
The front cross member is composed of a pipe member;
The left and right side portions each include a front portion into which the pipe member is inserted,
A lower arm is attached to the rear part.
A subframe characterized by that. The subframe according to claim 1, wherein
The rear cross member portion and the left and right inclined portions are hollow bodies,
The rear cross member is
An extending portion having a closed cross section and extending in the vehicle width direction;
Left and right widened portions provided at both ends in the vehicle width direction of the extended portion, and wider in the vehicle front-rear direction than the extended portion,
The extending portion is
The center in the vehicle width direction,
Left and right connecting portions, which are adjacent to the central portion and to which the left and right inclined portions are respectively connected;
And both end portions adjacent to the left and right widened portions,
The central portion has a closed cross section at a cut surface in the vehicle front-rear direction,
The both end portions have a closed cross section at a cut surface in the vehicle front-rear direction,
The left and right connecting portions and the left and right inclined portions have an integral closed cross section in a cut surface in the vehicle front-rear direction,
The integral closed cross section has an area larger than the closed cross section of the central portion and the closed cross sections of the both ends.
A subframe characterized by that. The subframe according to claim 2, wherein
The left and right side parts, the left and right inclined parts, and the rear cross member part are formed by a hollow body formed by vertically coupling an upper divided body and a lower divided body,
The pipe member is sandwiched between the upper divided body and the lower divided body,
A subframe characterized by that. The subframe according to claim 1, wherein
The rear cross member is
An extending portion extending in the vehicle width direction;
Left and right widened portions provided at both ends in the vehicle width direction of the extended portion, and wider in the vehicle front-rear direction than the extended portion,
The left and right side portions are supported by a front side frame,
The left and right widened portions include a front portion and a rear portion supported by the front side frame,
Lower arms are supported by the rear portions of the left and right side portions and the front portions of the left and right widened portions,
A subframe characterized by that. The subframe according to claim 1, wherein
The rear cross member is
An extending portion extending in the vehicle width direction;
Left and right widened portions provided at both ends in the vehicle width direction of the extended portion, and wider in the vehicle front-rear direction than the extended portion,
One of the left and right widened portions is provided with a torque rod mounting portion.
A subframe characterized by that. The subframe according to claim 1, wherein
The left and right side portions are supported by a front side frame,
The front end portion of the front side frame is widened in the vehicle width direction toward the front in the vehicle front-rear direction,
The left and right side portions are widened in the vehicle width direction toward the front in the vehicle front-rear direction.
A subframe characterized by that.

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