Vehicle suspension device

Abstract

To provide a suspension device for a vehicle which can relieve impact against a passenger compartment in period from collision beginning to collision later stage at off-set collision while restraining a body weight from increasing.SOLUTION: A lower arm 17 of a suspension device 2 includes a front side member 171 and a rear side member 172. The front side member 171 extends in a vehicle width direction and is attached to a suspension side frame 11 at an inner part and supports a wheel 18 at an outside part. The rear side member 172 extends in a longitudinal direction of a vehicle and a front part thereof is connected to the front side member 171 and the rear part thereof is attached with the suspension side frame 11. The front side member 171 is formed from an aluminum alloy and the rear side member 172 is formed from a steel. The front side member 171 is formed so that its breaking load is equal to or less than impact load for prescribed collision load from a frontward direction and the rear side member 172 is formed so that its breaking load is higher than the impact load.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a suspension device for a vehicle. [Background technology]

[0002] Conventionally, a structure for mitigating impact to the vehicle interior during an offset collision has been adopted in vehicles. In particular, in recent years, there has been a demand for a structure that can sufficiently mitigate impact to the vehicle interior even during a small overlap collision in which an obstacle collides from the front with the outer 1 / 4 region in the vehicle width direction. Patent Document 1 discloses a structure for mitigating impact to the vehicle interior even during a small overlap collision.

[0003] Patent Document 1 discloses a vehicle front structure including a suspension side frame extending in the longitudinal direction of the vehicle, a lower arm connected to the suspension side frame on the inner side in the vehicle width direction and supporting a wheel at an outer end in the vehicle width direction, and a side member connected to the front part of the suspension side frame and extending in the longitudinal direction of the vehicle. The lower arm has a front arm portion extending in the vehicle width direction and supporting a wheel at an outer end, and a rear arm portion continuing from a rear end portion of the front arm portion and extending in the longitudinal direction of the vehicle. The lower arm is attached to the suspension side frame at an inner part in the vehicle width direction of the front arm portion and an inner part in the vehicle width direction of the rear arm portion. The side member is provided with a protrusion portion extending in the longitudinal direction of the vehicle and positioned forward at a portion where the rear end is slightly outboard of the attachment portion of the front arm portion to the suspension side frame in the vehicle width direction.

[0004] In the vehicle disclosed in Patent Document 1, in an offset collision including a micro overlap collision, the protrusion is displaced rearward together with the side member which is displaced rearward by the front impact load, and the rear end of the protrusion breaks the attachment part of the front arm to the suspension side frame and other parts. As a result, the lower arm rotates outward in the vehicle width direction with the attachment part of the rear arm to the suspension side frame as the rotation center, and the direct transmission of the impact to the passenger compartment via the wheels is mitigated. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-37241 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the vehicle disclosed in Patent Document 1, since the front arm breaks as described above in the early stage of an offset collision, the lower arm cannot be used as a shock transmission path (load path) in the early stage of the collision. That is, in the early stage of an offset collision, it is desirable to guide the vehicle toward the opposite side of the collision barrier in the vehicle width direction from the viewpoint of mitigating the shock to the passenger compartment. However, in the vehicle disclosed in Patent Document 1, since the lower arm breaks in the early stage of an offset collision, the collision load cannot be input to the vehicle toward the opposite side of the collision barrier in the vehicle width direction in the early stage of the collision.

[0007] In order to ensure an impact transmission path in the early stages of a collision, it is possible to consider reinforcing other parts of the front of the vehicle, such as the side frames. However, reinforcing other components in this way would result in an increase in the weight of the vehicle.

[0008] The present invention has been made to solve the above-mentioned problems, and has an object to provide a vehicle suspension device that can reduce the impact on the passenger compartment from the initial stage of an offset collision to the later stage of the collision while suppressing an increase in vehicle weight. [Means for solving the problem]

[0009] A vehicle suspension device according to one aspect of the present invention includes a pair of side frames and a pair of arms. The pair of side frames each extend in the front-rear direction of the vehicle and are spaced apart from each other in the vehicle width direction. The pair of arms are attached to the pair of side frames, respectively, and support a wheel. Each of the pair of arms has a front member and a rear member. The front member extends in the vehicle width direction, an inner portion of the front member is attached to the side frame, and an outer portion of the front member supports the wheel. The rear member extends in the front-rear direction of the vehicle, a front portion of the front member is connected to the front member, and a rear portion of the rear member is attached to the side frame.

[0010] In the vehicle suspension device of this embodiment, the front member and the rear member are configured such that the rear member is constructed from a material having a higher strength than the front member, and such that, in the event of a predetermined collision load from the front of the vehicle, the breaking load of the front member is equal to or less than the predetermined impact load, and the breaking load of the rear member is higher than the predetermined impact load.

[0011] In the vehicle suspension device according to the above aspect, the arm is configured so that neither the front member nor the rear member breaks when a load smaller than a predetermined impact load is input from the front. Therefore, in the early stage of an offset collision (the period during which a load smaller than the predetermined impact load is input), the front member does not break and deforms together with the rear member, so that the impact load can be input toward the opposite side to the collision barrier via the front member and the rear member. Therefore, in the vehicle suspension device according to the above aspect, it is possible to ensure an impact transmission path (load path) in the early stage of a collision without reinforcing other parts of the front of the vehicle, such as the side frames.

[0012] On the other hand, in the vehicle suspension device according to the above aspect, when a load equal to or greater than a predetermined impact load acts on the arm in the later stage of an offset collision, the front member breaks but the rear member does not break. Therefore, in the vehicle suspension device according to the above aspect, the behavior of the wheel can be controlled by breaking the front member in the later stage of an offset collision.

[0013] In the vehicle suspension device relating to the above-mentioned aspect, each of the pair of side frames may have a protruding portion at the portion where the rear member is attached, which protrudes outward in the vehicle width direction, the rear member may have an attachment portion that is attached to the protruding portion in the fore-and-aft direction of the vehicle, and the rear member may have a convex portion that faces the protruding portion and protrudes inward in the vehicle width direction from the attachment portion.

[0014] In the vehicle suspension device according to the above aspect, since the rear member has a convex portion, even when a collision load is input from the front, the arm is prevented from moving straight toward the rear of the vehicle, and a moment for transmitting the load toward the inside in the vehicle width direction can be generated, which is advantageous in mitigating the impact on the vehicle interior during an offset collision.

[0015] The vehicle suspension device according to the above aspect may further include at least one cross member disposed between the pair of side frames.

[0016] In the vehicle suspension device according to the above aspect, since at least one cross member is provided, the impact load input to the arm during an offset collision can be transmitted to the inside in the vehicle width direction, which is advantageous in mitigating the impact on the vehicle interior during an offset collision.

[0017] In the vehicle suspension device of the above-mentioned aspect, the at least one cross member may include a front cross member installed between the locations where the front members are attached on the pair of side frames, and a rear cross member installed between the locations where the rear members are attached on the pair of side frames.

[0018] In the vehicle suspension device according to the above aspect, since the vehicle suspension device includes the front cross member and the rear cross member, the impact load input to the arm during an offset collision can be transmitted to the inside in the vehicle width direction via both cross members, which is advantageous in mitigating the impact on the vehicle interior during an offset collision.

[0019] In the vehicle suspension device according to the above aspect, the front member may have a groove portion at a portion outboard in a vehicle width direction relative to a connection point between the front member and the rear member.

[0020] In the vehicle suspension device relating to the above-described aspect, the front member has a groove portion, so that when a load equal to or greater than a predetermined impact load is input in the later stages of an offset collision, the front member can be broken starting from the groove portion, thereby enabling more reliable control of the wheel behavior.

[0021] In the vehicle suspension device relating to the above-mentioned aspect, the pair of arms may be lower arms supporting a lower end of the suspension, each of the pair of arms having a hole penetrating in the fore-and-aft direction of the vehicle in a portion supporting the lower end of the suspension, and the groove portion may be formed on at least one main surface of the arm in the fore-and-aft direction of the vehicle, so as to extend from an edge of the hole toward at least one of the upper and lower directions of the vehicle.

[0022] In the vehicle suspension device according to the above aspect, the groove portion is formed to extend from the edge of the hole provided to support the suspension, so that when the front member breaks in the later stages of an offset collision, the support of the suspension is also released, enabling more reliable control of the wheel behavior.

[0023] In the vehicle suspension device according to the above aspect, the front member may be formed of a light alloy, and the rear member may be formed of steel.

[0024] In the vehicle suspension device according to the above aspect, the front member is made of a light alloy (aluminum alloy, magnesium alloy, titanium alloy, etc.) and the rear member is made of steel (metal material containing Fe as a main component), so that the weight can be reduced compared to when the entire arm is made of steel. Furthermore, by making the front member of a light alloy, it is easily possible to set the strength of the front member relatively lower than that of the rear member, which is even more advantageous in ensuring that the front member breaks in the later stages of an offset collision.

[0025] In the vehicle suspension device according to the above aspect, the front member and the rear member may be connected to each other at a plurality of locations spaced apart in the vehicle width direction.

[0026] In the vehicle suspension device according to the above aspect, the front member and the rear member are connected at multiple points spaced apart in the vehicle width direction, so that displacement in which the front member and the rear member rotate relatively around the connection points is suppressed in the early stage of an offset collision. Thus, the vehicle suspension device according to the above aspect is advantageous in ensuring an impact transmission path in the early stage of a collision. Effect of the Invention

[0027] The vehicle suspension device according to each of the above aspects can mitigate the impact on the vehicle interior from the initial stage to the later stage of an offset collision while suppressing an increase in the vehicle body weight. [Brief description of the drawings]

[0028] [Figure 1] 1 is a plan view showing a front part of a vehicle to which a vehicle suspension device according to an embodiment is applied; [Diagram 2] FIG. 2 is an enlarged plan view of part A in FIG. [Diagram 3] FIG. 2 is a perspective view showing a partial configuration of the lower arm. [Figure 4] 13 is a plan view showing a connecting portion between a rear member and a bracket in the lower arm. FIG. [Diagram 5] 4 is a front view of the front member as viewed from the front side of the vehicle. FIG. [Figure 6] FIG. 2 is a cross-sectional view taken along line VI-VI of FIG. [Figure 7] FIG. 11 is a plan view showing a change in shape of the lower arm at the beginning of a minute overlap collision. [Figure 8] FIG. 11 is a plan view showing a change in shape of the lower arm during the middle stage of a collision. [Figure 9] 11 is a perspective view showing a state in which the lower arm is broken at the groove portion in a later stage of the collision. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example of the present invention, and the present invention is not limited to the following embodiment except for the essential configuration.

[0030] In the figures used in the following description, "Fr" indicates the front of the vehicle, "Re" indicates the rear of the vehicle, "Le" indicates the left side of the vehicle, "Ri" indicates the right side of the vehicle, "Up" indicates the top of the vehicle, and "Lo" indicates the bottom of the vehicle.

[0031] 1. Configuration of vehicle front portion 1a The configuration of a vehicle front portion 1a of a vehicle 1 to which a suspension device 2 according to an embodiment is applied will be described with reference to Fig. 1. Note that Fig. 1 illustrates only a part of the configuration of the vehicle front portion 1a.

[0032] As shown in Fig. 1, the vehicle front portion 1a is provided with a pair of suspension side frames (side frames) 11 formed to extend in the vehicle front-rear direction and spaced apart from each other in the vehicle width direction, in front of a floor panel 14. A member 10 is joined to the front end of each of the pair of suspension side frames 11. A front beam 20 extending in the vehicle width direction is joined to the front ends of the pair of members 10.

[0033] A front cross member 12 and a rear cross member 13 are installed from the front side between the pair of suspension side frames 11. The front cross member 12 and the rear cross member 13 are disposed at an interval from each other in the front-to-rear direction of the vehicle.

[0034] A pair of side sills 15, each extending in the front-rear direction of the vehicle, are provided on both sides in the vehicle width direction of the floor panel 14. The floor panel 14 also has a pair of floor reinforcements 16 arranged such that the distance between them gradually increases from the front side to the rear side of the vehicle.

[0035] A pair of lower arms (arms) 17 are attached to the outer portions in the vehicle width direction of each of the pair of suspension side frames 11. Each of the pair of lower arms 17 supports a front wheel (wheel) 18 on the outer side in the vehicle width direction. Although a detailed description is omitted, the front wheel 18 is supported by the lower arm 17 via a knuckle (not shown).

[0036] A stabilizer bar 19 is connected to the front side of the pair of lower arms 17. Further, each of the pair of lower arms 17 is attached to the suspension side frame 11 via a bracket (projection portion) 21 at its rear portion.

[0037] The suspension device 2 according to this embodiment includes a pair of suspension side frames 11 and a pair of lower arms 17 as components.

[0038] 2. Configuration of lower arm 17 The detailed structure of the lower arm 17 and the manner in which the lower arm 17 is attached to the suspension side frame 11 will be described with reference to Figs.

[0039] 2, each of the pair of lower arms 17 has a front member 171 disposed at the front side in the vehicle front-rear direction and a rear member 172 disposed at the rear side. The front member 171 extends in the vehicle width direction, and is attached to the suspension side frame 11 at an inner portion in the vehicle width direction, and supports the front wheel 18 at an outer end (outer portion). The front member 171 also supports the lower end of the suspension 22.

[0040] The rear member 172 extends in the vehicle front-rear direction, has its front part (front portion) connected to the front member 171, and is attached to the suspension side frame 11 via the bracket 21 at its rear part (rear portion).

[0041] 3, the rear member 172 has two fixing portions 172a, 172b spaced apart from each other in the vehicle width direction. The front member 171 and the rear member 172 are connected by a bolt BLT that passes through a through hole formed in the front member 171 from the front side in the vehicle front-rear direction and is screwed into a female thread formed in the fixing portions 172a, 172b of the rear member 172 (arrows C1, C2).

[0042] The front member 171 has three holes 171a, 171c, and 171d in addition to the through holes for inserting the bolts BLT. The hole 171a provided on the innermost side in the vehicle width direction is a hole used to attach the front member 171 to the suspension side frame 11. The hole 171c provided on the outer side in the vehicle width direction is a hole used to support the lower end of the suspension 22. The hole 171d provided at a position between the holes 171a and 171c in the vehicle width direction is a hole used to attach the stabilizer bar 19.

[0043] A ball joint 171b used for attachment to a knuckle is provided at the outermost portion in the vehicle width direction of the front member 171. The front member 171 supports the front wheel 18 via the knuckle to which it is attached using the ball joint 171b.

[0044] In a plan view from the vehicle top-bottom direction, the rear member 172 has an outer edge in the vehicle width direction formed in an arc shape that displaces from the outside to the inside as it goes from the front to the rear. The rear end of the rear member 172 has a mounting shaft portion (mounting portion) 172c used for mounting to the bracket 21, and a protrusion 172d that protrudes toward the inside in the vehicle width direction at the front end portion of the mounting shaft portion 172. The shaft portion 172c of the rear member 172 corresponds to the "mounting portion with the overhanging portion of the side frame." The mounting shaft portion 172c is oriented in the front-to-rear direction of the vehicle 1.

[0045] Here, in the suspension device 2 according to this embodiment, the front member 171 is made of an aluminum alloy, which is a type of light alloy, and the rear member 172 is made of steel. That is, in the suspension device 2 according to this embodiment, the rear member 172 is made of a material having a higher strength than the front member 171.

[0046] 2 and 3, in the suspension device 2 according to this embodiment, the attachment position of the front member 171 to the suspension side frame 11 is approximately the same as the joining position of the front cross member 12 to the suspension frame 11 in the vehicle longitudinal direction. Also, in the suspension device 2 according to this embodiment, the attachment position of the rear member 172 to the suspension side frame 11 (the position of the bracket 21) is approximately the same as the joining position of the rear cross member 13 to the suspension frame 11 in the vehicle longitudinal direction.

[0047] 3. Role of the protrusion 172d provided on the rear member 172 The role of the protrusion 172d provided on the rear member 172 will be described with reference to FIG.

[0048] 4, the rear member 172 of the lower arm 17 is attached to the suspension side frame 11 by fitting a mounting shaft portion 172c provided at the rear end into the bracket 21. The protrusion 172d of the rear member 172 abuts against or is close to the bracket 21 on the inner side in the vehicle width direction with respect to the axis Ax172 of the mounting shaft portion 172c (arrow D4).

[0049] When an impact load is input from the front to the lower arm 17 due to an offset collision with the vehicle 1 (arrow D1), the protruding portion 172d receives a forward reaction force from the bracket 21 (arrow D2). As a result, a force is generated from the mounting shaft portion 172c of the rear member 172 through the bracket 21 toward the suspension side frame 11 in the vehicle width direction, centered on the intersection point between the axis 172c of the mounting shaft portion 172c and the front end edge of the bracket 21 (arrow D3). As a result, in the suspension device 2, a moment for transmitting a load toward the inside in the vehicle width direction is generated during an offset collision.

[0050] 4. Configuration of the front member 171 The configuration of the front member 171 will be described with reference to Fig. 5. Fig. 5 is a front view of the front member 171 as viewed from the front side of the vehicle 1.

[0051] 5, the front member 171 has a hole 171a at its innermost portion in the vehicle width direction, and a ball joint 171b at its outermost portion. The front member 171 has holes 171e, 171d, 171f, and 171e between the hole 171a and the ball joint 171b in the vehicle width direction, in that order from the inner side in the vehicle width direction. Of these, the holes 171e and 171f are through holes through which the bolts BLT used for connection to the rear member 172 are inserted.

[0052] The front member 171 further has a groove 171g. The groove 171g is a portion that becomes the starting point of fracture of the front member 171 when a load equal to or greater than a predetermined collision load is input to the suspension device 2 during an offset collision. The groove 171g is formed so as to extend obliquely upward from the edge of the hole 171c used to support the lower end of the suspension 22. In the front member 171, the groove bottom of the groove 171g is formed to be thinner in the vehicle front-rear direction than the surrounding portions.

[0053] In this embodiment, the groove portion 171g is formed in such a manner that it is inclined inward in the vehicle width direction as it approaches the upper side of the vehicle 1.

[0054] 5. Structure of Floor Reinforcement 16 The structure of the floor reinforcement 16 will be described with reference to FIG.

[0055] As shown in Fig. 6, the floor reinforcement 16 is composed of a floor panel member 161 and hat-shaped members 162, 163. The hat-shaped members 162, 163 are each members having a hat-shaped cross section, and are disposed facing each other so as to sandwich the floor panel 161 in the vertical direction. The combination of the floor panel member 161 and the hat-shaped members 162, 163 allows the floor reinforcement 16 to have a closed cross-sectional structure.

[0056] The floor reinforcement 16, which is configured with a closed cross-sectional structure shown in FIG. 6, serves as an impact transmission path (load path) for transmitting the collision load to both sides where the side sills 15 are provided when a collision load is input from the front of the vehicle 1.

[0057] 6. Shape change of lower arm 17 during a micro overlap collision The change in shape of the lower arm 17 when the vehicle 1 is involved in a slight overlap collision will be described with reference to Figures 7 to 9. Note that the front wheels 18 and the suspension 22 are omitted from Figures 7 and 8, and Figure 9 shows only a portion of the lower arm 17.

[0058] As shown in Fig. 7, in the early stage of a micro-lap collision of the vehicle 1, the front member 171 of the lower arm 17 mainly begins to deform under the load E1 from the collision barrier 500. Since the front member 171 is made of a light alloy having a lower strength than the rear member 172, the outer side in the vehicle width direction where the ball joint 171b is provided deforms so as to be displaced rearward, and the rear member 172 made of steel hardly deforms at all in the early stage of the collision shown in Fig. 7.

[0059] As the front member 171 deforms, a load directed toward the inside in the vehicle width direction as indicated by arrow E2 acts on the rear member 172 via the fixing parts 172a, 172b. Then, a load directed toward the inside in the vehicle width direction as indicated by arrow E3 acts on the suspension side frame 11 via the bracket 21. In this way, in the suspension device 2 according to this embodiment, at the early stage of a minute overlap collision, the collision load can be applied toward the inside in the vehicle width direction (the opposite side to the collision barrier 500) via the rear member 172.

[0060] As shown in FIG. 8, even in the middle stage of a micro-lap collision of the vehicle 1, the suspension side frame 11 can be caused to act on the inside in the vehicle width direction (opposite side from the collision barrier 500) in response to the load F1 input from the collision barrier 500 (arrows F2, F3), as long as the collision load input to the front member 171 does not exceed the breaking load of the front member 171.

[0061] 9, when the collision load input to the front member 171 becomes equal to or greater than the breaking load of the front member 171 during the later stage of the minute overlap collision, the front member 171 breaks from the groove 171g, and the outer end 171h separates (arrow G). In this case, since the groove 171g is formed so as to extend from the edge of the hole 171c, the separation of the outer end 171h also releases support for the lower end of the suspension 22.

[0062] 7.Effects In the suspension device 2 according to this embodiment, the lower arm 17 is configured so that neither the front member 171 nor the rear member 172 breaks when a load smaller than a predetermined impact load is input from the front. Therefore, in the early stage of an offset collision (including a minute overlap collision) (a period during which a load smaller than the predetermined impact load is input), the front member 171 deforms together with the rear member 172 without breaking, so that the impact load can be input toward the opposite side (inner side in the vehicle width direction) from the collision barrier 500 via the front member 171 and the rear member 172. Therefore, in the suspension device 2, it is possible to ensure an impact transmission path (load path) in the early stage of a collision without reinforcing other parts of the front part of the vehicle, such as the side frames.

[0063] In the suspension unit 2, if a load equal to or greater than a predetermined impact load acts on the front member 171 of the lower arm 17 in the later stage of an offset collision (including a micro-lap collision), the front member 171 breaks. Therefore, in the suspension unit 2, the behavior of the front wheel 18 can be controlled by breaking only the front member 171 in the later stage of an offset collision.

[0064] Furthermore, in the suspension device 2 according to this embodiment, the rear member 172 has the protrusion 172d, so that even when a collision load is input from the front, the rear end of the rear member 172 of the lower arm 17 is prevented from moving straight toward the rear of the vehicle, and a moment for transmitting the load toward the inside in the vehicle width direction can be generated. This is advantageous in mitigating the impact on the vehicle interior during an offset collision.

[0065] Furthermore, since the suspension device 2 according to this embodiment includes the cross members 12 and 13, the impact load input to the lower arm 17 during an offset collision (including a slight overlap collision) can be transmitted to the inside in the vehicle width direction, which is advantageous in mitigating the impact on the vehicle interior during an offset collision.

[0066] Furthermore, since the suspension device 2 according to this embodiment includes the front cross member 12 and the rear cross member 13, the impact load input to the lower arm 17 during an offset collision (including a slight overlap collision) can be transmitted to the inside in the vehicle width direction via both cross members 12, 13. This is advantageous in mitigating the impact to the vehicle interior during an offset collision.

[0067] Furthermore, in the suspension device 2 of this embodiment, the front member 171 of the lower arm 17 has the groove portion 171g, so that when a load equal to or greater than a predetermined impact load is input in the later stages of an offset collision, the front member 171 can be broken starting from the groove portion 171g, and the behavior of the front wheel 18 can be controlled more reliably.

[0068] Furthermore, in the suspension device 2 according to this embodiment, the groove portion 171g is formed to extend from the edge of the hole 171c provided to support the lower end of the suspension 22. Therefore, when the front member 171 breaks in the later stages of an offset collision, the support of the suspension 22 is also released, making it possible to more reliably control the behavior of the front wheel 18.

[0069] Furthermore, in the suspension device 2 according to this embodiment, the front member 171 is formed from a light alloy (aluminum alloy, as one example), and the rear member 172 is formed from steel (metal material containing Fe as a main component), so that it is possible to achieve a weight reduction compared to a case in which the entire lower arm 17 is formed from steel. Furthermore, by forming the front member 171 from an aluminum alloy, it is possible to easily set the strength of the front member 171 to be relatively lower than that of the rear member 172, which is further advantageous in ensuring that the front member 171 breaks in the later stage of an offset collision.

[0070] In addition, in the suspension device 2 according to this embodiment, the front member 171 and the rear member 172 are connected by the bolts BLT at two points spaced apart in the vehicle width direction, so that displacement in which the front member 171 and the rear member 172 rotate relatively around the connection point is suppressed in the early stage of an offset collision. Therefore, the suspension device 2 is advantageous in ensuring an impact transmission path in the early stage of a collision.

[0071] As described above, the suspension device 2 of this embodiment can mitigate the impact on the vehicle cabin from the early stage to the later stage of an offset collision (including a small overlap collision) while suppressing an increase in vehicle weight.

[0072] [Variations] In the suspension device 2 according to the embodiment described above, the front member 171 is made of an aluminum alloy, but the present invention is not limited to this. Taking into consideration its relationship with the rear member 172, the front member 171 may be made of a material having a lower strength than the rear member 172.

[0073] In the suspension device 2 according to the embodiment described above, the rear member 172 is configured to have the protruding portion 172d, but in the present invention, it is not essential that the rear member 172 has the protruding portion 172d.

[0074] In the suspension device 2 of the above embodiment, a configuration is adopted in which two cross members 12, 13 are installed between a pair of suspension side frames 11. However, in the present invention, it is also possible to adopt a configuration in which a single cross member is installed between the suspension side frames 11.

[0075] In the suspension device 2 according to the above embodiment, a configuration was adopted in which the lower arm 17 includes a front member 171 and a rear member 172. However, in the present invention, it is also possible to adopt a configuration in which the upper arm includes a front member and a rear member similar to those in the above embodiment.

[0076] In the suspension device 2 according to the above embodiment, the groove 171g is formed so as to extend from the edge of the hole 171c in the front member 171, but in the present invention, it is not necessary to form the groove 171g so as to extend from the edge of the hole 171c. In other words, it is sufficient to provide the groove in a location where the greatest stress acts immediately before the front member 171 breaks when a collision load is input from the front.

[0077] In the suspension device 2 according to the embodiment described above, the front member 171 and the rear member 172 are attached to each other with two bolts BLT, but the front member 171 and the rear member 172 may be attached to each other with one bolt, or with three or more bolts. Furthermore, the attachment of the front member 171 and the rear member 172 is not limited to the form using the bolts BLT, and it is also possible to adopt a mounting form using rivets, welding, or the like. [Explanation of symbols]

[0078] 1 vehicle 1a Front of vehicle 2 Suspension device 11 Suspension side frame (side frame) 12 Front cross member 13 Rear cross member 17 Lower arm (arm) 18 Front wheel (wheel) 21 Bracket (extension) 171 Front member 171g Groove 172 Rear member 172c Mounting shaft part (mounting part) 172d Convex

Claims

1. A pair of side frames each extending in a front-rear direction of the vehicle and spaced apart from each other in a vehicle width direction; A pair of arms attached to each of the pair of side frames and supporting wheels; Equipped with Each of the pair of arms is a front member extending in a vehicle width direction, attached to the side frame at an inner portion, and supporting the wheel at an outer portion; a rear member extending in a front-rear direction of the vehicle, the front portion of which is connected to the front member and the rear portion of which is attached to the side frame; having The front member and the rear member are formed such that the rear member is made of a material having a higher strength than the front member, and that, with respect to a predetermined collision load from the front of the vehicle, the breaking load of the front member is equal to or smaller than the predetermined impact load, and the breaking load of the rear member is higher than the predetermined impact load. A suspension device for a vehicle.

2. 2. The vehicle suspension device according to claim 1, Each of the pair of side frames has a protruding portion provided so as to protrude outward in a vehicle width direction at a portion to which the rear member is attached, The rear member includes an attachment portion that is attached to the protruding portion in the front-rear direction of the vehicle, and the rear member has a convex portion that faces the protruding portion and protrudes inward in the vehicle width direction from the attachment portion. A suspension device for a vehicle.

3. 3. The vehicle suspension device according to claim 1, At least one cross member is further provided between the pair of side frames. A suspension device for a vehicle.

4. 4. The vehicle suspension device according to claim 3, The at least one cross member is a front cross member disposed between the positions of the pair of side frames to which the front member is attached; a rear cross member disposed between the locations of the pair of side frames to which the rear members are attached; Including, A suspension device for a vehicle.

5. The vehicle suspension device according to any one of claims 1 to 4, The front member has a groove portion on a portion on the outer side in a vehicle width direction than a connection portion with the rear member. A suspension device for a vehicle.

6. 6. The vehicle suspension device according to claim 5, The pair of arms are lower arms supporting a lower end of a suspension, Each of the pair of arms has a hole penetrating in a front-rear direction of the vehicle in a portion supporting a lower end of the suspension, The groove portion is formed on at least one of the main surfaces of the arm in the front-rear direction of the vehicle so as to extend from an edge of the hole toward at least one of the upper and lower directions of the vehicle. A suspension device for a vehicle.

7. 7. The vehicle suspension device according to claim 1, The front member is formed of a light alloy, The rear member is made of steel. A suspension device for a vehicle.

8. The vehicle suspension device according to any one of claims 1 to 7, The front member and the rear member are connected to each other at a plurality of points spaced apart in the vehicle width direction. A suspension device for a vehicle.

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