JP6137487B2 - Rear subframe structure of automobile - Google Patents

Description

  The present invention relates to a rear subframe structure of an automobile, and more particularly, to a rear subframe structure of an automobile that is attached to a kick-up portion and a rear frame of a vehicle body and is a part of a multi-link type rear suspension device.

  In assembling an automobile, it is known that a link and an arm constituting a rear suspension are attached to a rear subframe structure, and further, a rear subframe structure is attached to a rear portion of a vehicle body from below.

  For example, left and right suspension members arranged so that the longitudinal direction thereof is along the vehicle longitudinal direction, a front cross member that is coupled to the front end portions of the left and right suspension members and arranged along the vehicle width direction, and left and right suspension members A vehicle body rear structure including a rear cross member coupled to a rear end portion and disposed along a vehicle width direction is known (see, for example, Patent Document 1). In the vehicle body rear structure of Patent Document 1, a rear connection portion that connects the rear end portions of the left and right suspension members and the vehicle body, and an intermediate connection portion that connects the vehicle body and the intermediate portion in the front-rear direction of the left and right suspension members. And are provided. A suspension mounting portion to which the rear upper arm of the rear suspension is connected is provided on the vehicle width direction outer side of the rear connection portion to the vehicle body, and the vehicle at the intermediate connection portion to the vehicle body is provided. A suspension mounting portion to which the front upper arm of the rear suspension is connected is provided on the outer side in the width direction.

JP 2008-114652 A

  Here, the rear subframe structure is required to have high rigidity in order to improve the response of the suspension during traveling. However, if the rear subframe structure alone is to obtain high rigidity, the mass of the rear subframe structure itself is increased. Therefore, by cooperating the rear frame of the vehicle body arranged on the lower surface of the rear part of the vehicle body and the rear subframe structure attached to the rear frame of the vehicle body, the vehicle body without increasing the mass of the rear subframe structure itself. It is conceivable to obtain the rigidity required for the rear subframe structure in the state of a completed vehicle in which the rear subframe structure is attached to the rear frame.

  In this case, since the load is input to the rear frame of the vehicle body from the fastening point of the rear sub frame with respect to the rear frame of the vehicle body, the rear frame of the vehicle body needs to be reinforced. It is desirable to suppress as much as possible. However, when the front and rear positions of the mounting portion of the rear subframe with respect to the rear frame of the vehicle body are the same as the front and rear positions of the mounting portion of the suspension arm with respect to the rear subframe as in the prior art described above, the front suspension with respect to the rear subframe is used. From the position of the arm mounting portion to the position of the rear suspension arm mounting portion, the rear frame of the vehicle body must be reinforced along the vehicle front-rear direction, which increases the mass of the rear frame of the vehicle body. is there.

  The present invention has been made to solve the above-described problems of the prior art, and while suppressing the increase in the mass of the rear frame of the vehicle body, the rear subframe structure is attached to the rear frame of the vehicle body while the rear subframe structure is attached. An object of the present invention is to provide a rear subframe structure for an automobile that can obtain the rigidity required for the subframe structure.

In order to achieve the above object, a rear subframe structure for an automobile according to the present invention is attached to a kick-up portion of a vehicle body and a rear frame, and forms a part of a multi-link type rear suspension device. A pair of side members that extend in the longitudinal direction of the vehicle body on both the left and right sides in the vehicle width direction and whose front end portions are coupled to the front portion of the kick-up portion of the vehicle body, and the pair of side members that are coupled to each other. The front cross member that extends in the width direction and whose left and right ends are connected to the rear frame of the vehicle body at a position higher than the side members, and the side members are connected to each other at the rear ends of the pair of side members. The rear frame of the vehicle body extends in the width direction and its left and right ends are higher than the side members behind the kick-up portion of the vehicle body. A first cross-linking member, and a first attachment portion to which end portions of a pair of left and right suspension links on the vehicle body side are attached. A second mounting portion that is disposed behind the pair of left and right connecting points of the front cross member with respect to the rear frame of the vehicle body and to which the vehicle body side ends of the other pair of left and right suspension links among the suspension links is mounted, It is arranged behind a pair of left and right connecting points of the rear cross member with respect to the rear frame of the vehicle body.
In the present invention configured as described above, the connecting point of the front cross member where the rear sub-frame structure is connected to the rear frame of the vehicle body is ahead of the first attachment portion where the suspension link is attached to the rear sub-frame structure. The connecting point of the rear cross member, which is arranged and connected to the rear frame of the vehicle body, is arranged in front of the second attachment portion where the suspension link is attached to the rear sub-frame structure. In order to obtain the necessary rigidity for the rear subframe structure in the state of the finished vehicle by cooperating with the frame structure, it is only necessary to reinforce the rear frame of the vehicle body to a position ahead of the mounting portion of the rear suspension link. In addition, the longitudinal length of reinforcing the rear frame of the vehicle body can be shortened. Therefore, the rigidity required for the rear subframe structure can be obtained in a state where the rear subframe structure is attached to the rear frame of the vehicle body while suppressing an increase in the mass of the rear frame of the vehicle body.
Further, as described above, when the rigidity required for the rear subframe structure is obtained in the state of the completed vehicle by cooperating the rear frame of the vehicle body and the rear subframe structure, the rear suspension link mounting portion Since the rear frame of the vehicle body only needs to be reinforced to the front position, the increase in mass due to this reinforcement can be concentrated on the center side of the vehicle, and the turning ability of the vehicle can be improved.
Further, the connecting point of the front and rear cross members where the rear subframe structure is connected to the rear frame of the vehicle body and the first and second mounting portions where the suspension link is attached to the rear subframe structure are offset in the front-rear direction. Therefore, the connecting point of the front cross member and the rear cross member with respect to the vehicle body does not interfere with the first and second mounting portions of the suspension link, and the strength is arranged on the outermost side in the vehicle width direction. It can be provided on a pair of left and right rear side frames which are members. This can increase the length in the vehicle width direction in which the vehicle body receives a load from the rear subframe structure, which is advantageous in reducing torsion when the vehicle body receives a load from the rear subframe structure.

In the present invention, preferably, the first attachment portion includes a pair of left and right lateral links extending in the vehicle width direction from the vehicle body side toward the wheel side, out of suspension links provided in the multilink type rear suspension device. An end portion on the vehicle body side is attached, and the second attachment portion includes a pair of left and right extending from the vehicle body side toward the wheel side toward the front of the vehicle body in a suspension link included in the multi-link type rear suspension device. The end of the body side of the leading link is attached.
In the present invention configured as described above, the front link angle of the leading link is increased from the wheel by increasing the forward tilt angle of the leading link from the viewpoint of improving the performance of the rear suspension device. Even when the vehicle is located far behind, it is only necessary to reinforce the rear frame of the car body up to the position ahead of the mounting part of this leading link. Can do.
In a multi-link type rear suspension device, a drive shaft or suspension damper that swings up and down is disposed between the lateral link and the leading link, but the connection point of the front cross member to the vehicle body is the vehicle body of the lateral link. Since it is arranged in front of the side mounting portion (first mounting portion), it is possible to prevent interference between this connection point and the drive shaft and suspension damper and deterioration of assembly workability.

  According to the rear subframe structure of an automobile according to the present invention, the rigidity required for the rear subframe structure is obtained with the rear subframe structure attached to the rear frame of the vehicle body while suppressing an increase in the mass of the rear frame of the vehicle body. be able to.

1 is a perspective view of a rear suspension device to which a rear sub-frame structure for an automobile according to an embodiment of the present invention is applied, viewed from an oblique left side in front of a vehicle body. It is the perspective view which looked at the rear sub-frame structure of the motor vehicle by the embodiment of the present invention from the slanting left side ahead of the body. It is the top view which looked at the rear sub-frame structure of the motor vehicle by embodiment of this invention from the vehicle body upper direction. It is the front view which looked at the rear sub-frame structure of the motor vehicle by the embodiment of the present invention from the body front. It is the side view which looked at the rear suspension apparatus which applied the rear sub-frame structure of the motor vehicle by embodiment of this invention from the vehicle body left side. FIG. 3 is a partially enlarged perspective view of the vicinity of the connection position between the rear subframe structure of the automobile and the rear side frame according to the embodiment of the present invention, as viewed from the diagonally left side in front of the vehicle body. FIG. 6 is a partially enlarged plan view of the vicinity of the connection position of the suspension link to the right side member as viewed from above the vehicle body. FIG. 5 is a view taken along the line VIII-VIII in FIG. 4 and showing the internal structure of the right side member. It is the rear view which looked at the rear sub-frame structure of the motor vehicle by the embodiment of the present invention from the body back. FIG. 10 is a view taken along the line X-X in FIG. 9 and showing the vicinity of the stabilizer support base of the rear cross member according to the embodiment of the present invention. It is the elements on larger scale which looked at the stabilizer support base vicinity of the rear cross member by the embodiment of the present invention from the slanting left side behind the body.

Hereinafter, a rear subframe structure of an automobile according to an embodiment of the present invention will be described with reference to the accompanying drawings.
First, referring to FIG. 1, a rear suspension device to which a rear subframe structure of an automobile according to an embodiment of the present invention is applied will be described. FIG. 1 is a perspective view of a rear suspension device to which a rear subframe structure of an automobile according to an embodiment of the present invention is applied, viewed from an oblique left side in front of a vehicle body.

  In FIG. 1, reference numeral 1 denotes a rear suspension device. The rear suspension device 1 of the present embodiment is provided in a rear wheel drive vehicle in which a rear differential gear is disposed below a rear portion of a vehicle body to drive a rear wheel. The rear suspension device 1 mainly includes a rear subframe 2 and rear suspensions 4 provided on the left and right sides of the rear subframe 2 in the vehicle width direction.

  The rear suspension 4 is a multi-link suspension in which a wheel support member 6 for a rear wheel is connected to a vehicle body so as to be able to reciprocate in the vertical direction by five independent suspension links. The five suspension links include three lower links and two upper links. The wheel support member 6 is connected to the lower end portion of the suspension damper 18.

  Next, a rear subframe structure of an automobile according to an embodiment of the present invention will be described with reference to FIGS. FIG. 2 is a perspective view of a rear subframe structure of an automobile according to an embodiment of the present invention as seen from an oblique left side in front of the vehicle body, and FIG. 3 shows a rear subframe structure of the automobile according to an embodiment of the present invention from above the vehicle body. FIG. 4 is a front view of a rear subframe structure of an automobile according to an embodiment of the present invention as viewed from the front of the vehicle body.

  The rear subframe 2 includes a pair of left and right side members 20 extending in the longitudinal direction of the vehicle body on the left and right sides in the vehicle width direction, a front cross member 22 extending in the vehicle width direction so as to connect the pair of left and right side members 20 to each other, A rear cross member 24 extending in the vehicle width direction is provided so as to connect the rear ends of the pair of side members 20. The side member 20, the front cross member 22, and the rear cross member 24 are formed in a closed cross section with a metal (for example, a light metal such as an iron-based metal or an aluminum alloy).

  In particular, as shown in FIG. 4, the pair of left and right side members 20 extend in the longitudinal direction of the vehicle body, and the distance between the front ends is larger than the distance between the rear ends. That is, the pair of left and right side members 20 are formed so as to go outward in the vehicle width direction in a straight line toward the front. Further, the side member 20 is gently curved so as to protrude downward in a side view.

The front cross member 22 is formed between the left and right side members 20 between the front end portion and the rear end portion of the pair of left and right side members 20, more specifically at a position slightly ahead of the middle position in the front-rear direction of the side members 20. Are connected. Further, the front cross member 22 is formed in a substantially V shape when viewed from the front, and the height of both ends of the front cross member 22 is higher than that of the side member 20.
The front cross member 22 is connected between the front end portion and the rear end portion of the left and right side members 20 between the center portion and the left and right end portions.

  The front cross member 22 passes under the rear differential gear 26 attached to the rear portion of the vehicle body, particularly as shown in FIGS. 3 and 4 in a state where the rear subframe 2 is attached to the kick-up portion and the rear frame of the vehicle body. Are arranged as follows. That is, the rear differential gear 26 is located between the lower surface of the rear portion of the vehicle body and the front cross member 22.

  More specifically, as shown in FIG. 4, the front cross member 22 has a lowermost portion (that is, a V-shaped bottom portion in front view) from the center in the vehicle width direction (shown by a one-dot chain line) of the ring gear 28 of the rear differential gear 26. It is formed so as to be offset to a certain side (indicated by a broken line). More specifically, the lowermost portion of the front cross member 22 is positioned at the front lower side of the portion having the largest outer diameter, that is, the portion covering the ring gear 28 in the gear case 30 of the rear differential gear 26.

  In the front cross member 22, a straight line is formed between one end portion on the side where the ring gear 28 of the rear differential gear 26 is located and the lowermost portion. Further, the front cross member 22 has a bent portion 22a bent upward so as to be bent between the other end portion of the rear differential gear 26 on the side where the ring gear 28 is not present and the lowermost portion. In a state where the rear subframe 2 is attached to the rear portion of the vehicle body from below, an exhaust pipe 32 (shown by an imaginary line) is disposed below the bent portion 22a.

  The rear cross member 24 is connected to the rear ends of the pair of left and right side members 20 in the vicinity of the center thereof. Both end portions of the rear cross member 24 extend slightly outward in the vehicle width direction from the rear end portion of the side member 20 and are positioned higher than the rear end portion of the side member 20. The height positions of both ends of the front cross member 22 and the height positions of both ends of the rear cross member 24 are made substantially equal. The side member 20, the front cross member 22, and the rear cross member 24 are joined to each other by welding, for example.

  Next, with reference to FIG. 5, attachment of the rear subframe structure of the automobile to the vehicle body according to the embodiment of the present invention will be described. FIG. 5 is a side view of the rear suspension device 1 to which the rear subframe structure for an automobile according to the embodiment of the present invention is applied, as viewed from the left side of the vehicle body. In FIG. 5, the mounting position of the rear subframe 2 on the vehicle body is indicated by black stars.

  Here, the vehicle body includes a vehicle compartment floor portion 34 that constitutes the bottom surface of the vehicle compartment, a kick-up portion 36 that extends rearwardly and rearwardly from the rear end of the vehicle compartment floor portion 34, and an upper end of the kick-up portion 36 And a rear panel portion 38 extending horizontally rearward. The rear part of the kick-up part 36 is bent in the horizontal direction and connected to the rear panel part 38. In addition, a pair of rear side frames 40 (rear frames) extending in the front-rear direction on the left and right sides in the vehicle width direction are joined to the lower surface of the rear panel portion 38.

  The front end portions of the left and right side members 20 of the rear sub-frame 2 are connected to the front lower surface of the kick-up portion 36, respectively. Further, both end portions of the front cross member 22 are connected to the lower surfaces of the front end portions of the left and right rear side frames 40, respectively. In particular, as shown in FIG. 5, the connecting portion of the front cross member 22 to the rear side frame 40 is disposed on the front side of the front cross member 22. Further, both end portions of the rear cross member 24 are connected to the lower surfaces of the rear portions of the left and right rear side frames 40, respectively.

  Next, the suspension link mounting structure to the rear subframe 2 will be described in detail with reference to FIGS. FIG. 6 is a partially enlarged perspective view of the vicinity of the connection position between the left end portion of the front cross member 22 and the left end portion of the rear cross member 24 and the rear side frame 40 as viewed obliquely from the left front of the vehicle body, and FIG. FIG. 4 is a partially enlarged plan view of the vicinity of a connection position of a suspension link to a side member 20 as viewed from above the vehicle body. Further, in FIG. 5, the mounting positions of the above-described five suspension links to the rear subframe 2 are indicated by black circles.

  Five suspension links are attached to the rear subframe 2 on both the left and right sides in the vehicle width direction. Specifically, as shown in FIGS. 1, 5, and 6, a mounting portion 42 that protrudes upward is provided on the upper surface side of the front end portion of the pair of left and right side members 20. An end of the front lower link 8 (trailing link) on the vehicle body side is attached to 42 via a rubber bush. As shown in FIG. 7, the front lower link 8 extends rearwardly from the attachment portion 42 toward the rear of the vehicle body, and the end portion on the wheel side is connected to the wheel support member 6.

  Next, as shown in FIGS. 1, 6, and 7, a mounting portion 44 that protrudes outward in the vehicle width direction is provided above the connecting portion of the front cross member 22 to the side member 20. The end portion of the middle middle link 10 on the vehicle body side is attached to the attachment portion 44 via a rubber bush. The middle lower link 10 extends in the vehicle width direction from the attachment portion 44 toward the outside of the vehicle body, and the end portion on the wheel side is connected to the wheel support member 6.

  Next, as shown in FIGS. 6 and 7, mounting portions 46 projecting downward are provided on the lower surface side of both end portions in the vehicle width direction of the rear cross member 24. The vehicle body side end of the rear lower link 12 (toe control link) is attached via a rubber bush. As shown in FIGS. 1 and 7, the rear lower link 12 extends in the vehicle width direction from the attachment portion 46 toward the outside of the vehicle body, and the end portion on the wheel side is connected to the wheel support member 6.

  Next, as shown in FIGS. 1 and 6, the front cross member 22 is provided with mounting portions 48 that protrude outward in the vehicle width direction from both ends in the vehicle width direction. A vehicle body side end portion of the front upper link 14 (lateral link) is attached via a rubber bush. That is, as shown in FIGS. 5 and 6, the attachment portion 48 is disposed behind the connecting portion of the front cross member 22 to the rear side frame 40. The front upper link 14 extends in the vehicle width direction from the attachment portion 48 toward the outside of the vehicle body, and the end portion on the wheel side is connected to the wheel support member 6.

  Next, as shown in FIGS. 1, 5, and 6, the rear cross member 24 is provided with mounting portions 50 that protrude rearward from the both ends in the vehicle width direction. The end of the rear upper link 16 (leading link) on the vehicle body side is attached via a rubber bush. That is, as shown in FIGS. 5 and 6, the mounting portion 50 is disposed behind the connecting portion of the rear cross member 24 to the rear side frame 40. As shown in FIGS. 1, 5, and 6, the rear upper link 16 extends from the mounting portion 50 so as to tilt forward toward the front of the vehicle body, and the end on the wheel side is connected to the wheel support member 6.

  Next, the structure in the vicinity of the attachment portion 42 to the pair of left and right side members 20 of the front lower link 8 will be described in detail with reference to FIGS. FIG. 8 is a view taken along the line VIII-VIII in FIG. 4 and shows the internal structure of the right side member 20.

  First, as shown in FIG. 7, the side member 20 is formed so that the width of the cross section perpendicular to the longitudinal direction increases from the front and rear ends of the side member 20 toward the mounting portion 42 of the front lower link 8. Yes. That is, the cross-sectional area perpendicular to the longitudinal direction of the side member 20 is maximum below the attachment portion 42.

  As described above, the side member 20 is formed of a metal in a closed cross-sectional shape. As shown in FIG. 8, inside the side member 20, a flat plate-like reinforcing member 52 orthogonal to the longitudinal direction of the side member 20 is provided below the position where the front cross member 22 is connected. More specifically, the reinforcing member 52 is provided so as to be orthogonal to the longitudinal direction of the side member 20 below the vehicle body front side wall surface of the front cross member 22 and below the vehicle body rear side wall surface of the front cross member 22. It has been. These reinforcing members 52 are joined to the inner wall of the side member 20 by welding, for example.

  Next, referring to FIGS. 9 to 11, a structure for attaching the stabilizer to the rear subframe 2 will be described. FIG. 9 is a rear view of the rear subframe structure of the automobile according to the embodiment of the present invention as seen from the rear of the vehicle body. FIG. 10 shows the vicinity of the stabilizer support base of the rear cross member 24 according to the embodiment of the present invention from the left side of the vehicle body. FIG. 11 is a partially enlarged side view seen, and FIG. 11 is a view taken along the line XI-XI in FIG. 10 and shows the internal structure of the rear cross member 24.

  First, as shown in FIG. 9, a stabilizer base 54 is provided on the vehicle body rear side of the left and right ends of the rear cross member 24 in the vehicle width direction. More specifically, as shown in FIG. 10, the stabilizer pedestal 54 includes the lower surface of the mounting portion 50 of the rear upper link 16 projecting rearward from the both ends in the vehicle width direction of the rear cross member 24, and the rear cross member 24. It is provided so as to connect the rear side surface of the vehicle body. As shown in FIGS. 9 and 10, a stabilizer 58 is fixed to the rear side in the vehicle body direction of the pair of left and right stabilizer bases 54 using a stabilizer bracket 56. The stabilizer 58 extends further outward in the vehicle width direction from the position of the pair of left and right stabilizer bases 54, and both end portions on the wheel side are connected to the rear lower link 12 via links 60, for example.

  As described above, the rear cross member 24 is formed of a metal in a closed cross-sectional shape. As shown in FIG. 11, a flat reinforcing member 62 that is orthogonal to the longitudinal direction of the rear cross member 24 is provided in the rear cross member 24 in front of the stabilizer base 54. Further, a flat reinforcing member 64 that is orthogonal to the longitudinal direction of the rear cross member 24 is provided in the rear cross member 24 in front of the vehicle body of the mounting portion 50 of the rear upper link 16. These reinforcing members 62 and 64 are joined to the inner wall of the rear cross member 24 by welding, for example.

  Next, effects of the rear sub-frame structure of the automobile according to the above-described embodiment of the present invention will be described.

First, since the V-shaped bottom portion of the front cross member 22 in front view is offset from the center in the vehicle width direction to the side where the ring gear 28 of the rear differential gear 26 is present, the ring gear 28 of the rear differential gear 26 in the front cross member 22 is The lower space between the end portion on the non-side and the lowermost portion can be secured further. As a result, when the exhaust pipe 32 is disposed in the space, the rear differential gear 26 of the front cross member 22 is arranged. A portion between the end portion on the side where the ring gear 28 is not present and the lowermost portion can be formed more linearly while avoiding interference with the exhaust pipe 32. Therefore, the NVH performance can be improved without reinforcing the front cross member 22.
That is, NVH performance can be improved while avoiding interference between the front cross member 22 and the exhaust pipe 32 and suppressing an increase in weight due to reinforcement.

  In addition, since a larger space can be ensured between the end portion of the front cross member 22 on the side where the ring gear 28 of the rear differential gear 26 is not present and the lowermost portion, the exhaust pipe 32 is disposed in that space. In this case, it is possible to reliably avoid the interference between the front cross member 22 and the exhaust pipe 32 while improving the NVH performance.

Further, the connection point of the front cross member 22 where the rear subframe 2 is connected to the rear side frame 40 of the vehicle body is disposed in front of the mounting portion 48 where the front upper link 14 is attached to the rear subframe 2, and the rear side frame of the vehicle body is arranged. The connecting point of the rear cross member 24 that is connected to 40 is disposed in front of the mounting portion 50 to which the rear upper link 16 is attached to the rear subframe 2, so that the rear side frame 40 and the rear subframe 2 of the vehicle body are connected to each other. When the necessary rigidity is obtained for the rear sub-frame 2 in the state of the completed vehicle by cooperating, the rear side frame 40 of the vehicle body may be reinforced to a position ahead of the mounting portion 50 of the rear upper link 16. The longitudinal length of reinforcing the rear side frame 40 can be shortened. Therefore, it is possible to obtain the necessary rigidity for the rear subframe 2 while the rear subframe 2 is attached to the rear side frame 40 while suppressing an increase in the mass of the rear side frame 40 of the vehicle body.
Further, as described above, when the rear side frame 40 and the rear subframe 2 of the vehicle body cooperate to obtain the necessary rigidity for the rear subframe 2 in the state of the completed vehicle, the mounting portion 50 of the rear upper link 16 is obtained. Since it is only necessary to reinforce the rear side frame 40 of the vehicle body to a position ahead of it, an increase in mass due to this reinforcement can be concentrated on the center side of the vehicle, and the turning ability of the vehicle can be improved.
Further, the connecting points of the front and rear cross members 22 and 24 where the rear subframe 2 is connected to the rear side frame 40 of the vehicle body and the attachment portions 48 and 50 where the front and rear upper links 14 and 16 are attached to the rear subframe 2 are respectively Since the front cross member 22 and the rear cross member 24 are offset from each other in the front-rear direction, the connection points of the front cross member 22 and the rear cross member 24 in the vehicle width direction do not interfere with the attachment portions 48, 50 of the front and rear upper links 14, 16. It can be provided on the pair of left and right rear side frames 40 which are the strength members of the vehicle body arranged on the outermost side of the vehicle. Thus, the length of the vehicle body in the vehicle width direction that receives a load from the rear subframe 2 can be increased, which is advantageous in reducing torsion when the vehicle body receives a load from the rear subframe 2.

Further, from the viewpoint of improving the performance of the rear suspension device 1, by increasing the forward tilt angle of the rear upper link 16, even when the mounting portion 50 on the vehicle body side of the rear upper link 16 is located greatly rearward from the wheel, When the rear side frame 40 is reinforced, the rear side frame 40 may be reinforced to a position ahead of the mounting portion 50 of the upper link 16, and the longitudinal length of the rear side frame 40 of the vehicle body can be reduced.
In the multi-link type rear suspension device 1, a drive shaft or suspension damper 18 that swings vertically is disposed between the front upper link 14 and the rear upper link 16. Since the connecting point is disposed in front of the mounting portion 48 on the vehicle body side of the front upper link 14, it is possible to prevent interference between the connecting point and the drive shaft and the suspension damper 18 and deterioration of assembling workability.

Further, the side member 20 is formed so that the width of the cross section perpendicular to the longitudinal direction thereof increases from the front and rear ends of the side member 20 toward the mounting portion 42 of the front lower link 8. The bending rigidity and the torsional rigidity of the side member 20 in the vicinity of the mounting portion 42 can be improved, whereby the rigidity of the side member 20 with respect to the force applied to the side member 20 from the front lower link 8 via the mounting portion 42 can be improved. Can be improved.
Further, there is no need to provide an additional reinforcing member, and it is not necessary to provide the attachment portion 42 in the vicinity of the connecting portion between the front cross member 22 or the rear cross member 24 and the side member 20, so that an increase in weight due to reinforcement or a front lower The rigidity of the side member 20 against the force applied from the front lower link 8 can be improved without incurring the restriction of the attachment position of the link 8.

  Further, since a flat plate-like reinforcing member 52 orthogonal to the longitudinal direction of the side member 20 is provided below the connection position with the front cross member 22, the side member 20 is connected from the front lower link 8 via the attachment portion 42. In addition to improving the rigidity of the side member 20 with respect to the force applied to the side member 20, the rigidity of the side member 20 with respect to the force applied to the side member 20 from the front cross member 22 can be improved. And the rigidity can be further improved.

  Further, the lower surface of the mounting portion 50 of the rear upper link 16 that projects in a cantilevered manner from the upper end of the rear side surface of the rear cross member 24 to the rear side of the vehicle body and the rear side surface of the rear cross member 24 are connected to each other. Since the stabilizer pedestal 54 is provided, the stabilizer pedestal 54 can suppress the bending of the mounting portion 50 of the rear upper link 16 upward or downward of the vehicle body. Therefore, the bending of the attachment portion 50 due to the force applied from the rear upper link 16 can be suppressed without causing an increase in weight due to reinforcement.

  In addition, a flat reinforcing member 62 orthogonal to the longitudinal direction of the rear cross member 24 is provided in the rear cross member 24 in front of the vehicle body at a position where the rear cross member 24 is connected to the stabilizer pedestal 54. Thus, the rigidity of the rear cross member 24 against the force applied to the rear cross member 24 via the mounting portion 50 and the stabilizer pedestal 54 can be improved, so that the bending of the mounting portion 50 of the rear upper link 16 can be further ensured. Can be suppressed.

  In addition, a flat reinforcing member 64 perpendicular to the longitudinal direction of the rear cross member 24 is provided inside the rear cross member 24 in front of the vehicle body of the mounting portion 50 of the rear upper link 16. It is possible to improve the rigidity of the rear cross member 24 against the force applied to the rear cross member 24 from 16 through the mounting portion 50, and thereby more reliably suppress the bending of the mounting portion 50 of the rear upper link 16. Can do.

  The pair of side members 20 extend from the connecting position to the rear cross member 24 to the connecting position to the front part of the kick-up portion 36 of the vehicle body in the vehicle body longitudinal direction on both the left and right sides in the vehicle width direction and the vehicle width. Since it is formed so as to spread outward in the direction, the load at the time of rear collision is directly transmitted to the rear portion of the kick-up portion 36 via the rear side frame 40 and is also transmitted to the kick-up portion 36 via the side member 20. Is transmitted to the front of the. That is, since a part of the load at the time of the rear impact is distributed to the side member 20, the load applied to the bent portion at the rear portion of the kick-up portion 36 can be reduced, thereby causing buckling at the rear portion of the kick-up portion 36. The inclination of the kick-up portion 36 can be further raised while preventing this. Therefore, it is possible to shorten the longitudinal length of the vehicle body behind the passenger compartment while ensuring a structural strength equal to or higher than that of the conventional case with respect to the load at the time of rear collision.

  In addition, by dispersing a part of the load at the time of the rear collision to the side member 20, the load applied to the bent portion at the rear portion of the kick-up portion 36 is reduced, and a space for arranging the axle is provided above the side member 20. Can be secured.

DESCRIPTION OF SYMBOLS 1 Rear suspension apparatus 2 Rear sub-frame 4 Rear suspension 6 Wheel support member 8 Front lower link (trailing link)
10 Middle lower link 12 Rear lower link (toe control link)
14 Previous upper link (lateral link)
16 Rear upper link (reading link)
18 Suspension damper 20 Side member 22 Front cross member 22a Bent part 24 Rear cross member 26 Rear differential gear 28 Ring gear 30 Gear case 32 Exhaust pipe 34 Car compartment floor part 36 Kick-up part 38 Rear panel part 40 Rear side frame 42, 44, 46, 48 , 50 Mounting portion 52 Reinforcing member 54 Stabilizer base 56 Stabilizer bracket 58 Stabilizer 60 Link 62, 64 Reinforcing member

Claims (2)

A rear sub-frame structure of an automobile which is attached to a kick-up portion of a vehicle body and a rear frame and becomes a part of a multi-link type rear suspension device,
A pair of side members that extend in the longitudinal direction of the vehicle body on the left and right sides in the vehicle width direction, and whose front end portions are connected to the front portion of the kick-up portion of the vehicle body
A front cross member that extends in the vehicle width direction so as to connect the pair of side members to each other and whose left and right ends are connected to the rear frame of the vehicle body at a position higher than the side members;
The vehicle body extends in the vehicle width direction so as to connect the side members to each other at the rear end portions of the pair of side members, and the left and right ends thereof are higher than the side members behind the kick-up portion of the vehicle body. A rear cross member coupled to the rear frame of the
Of the suspension links provided in the multi-link type rear suspension device, the first attachment portion to which the vehicle body side ends of a pair of left and right suspension links are attached is the front cross member with respect to the rear frame of the vehicle body. Arranged behind the pair of left and right connecting points,
A second mounting portion to which the vehicle body side end portion of the other pair of left and right suspension links of the pair of suspension links is mounted is located behind the pair of left and right connecting points of the rear cross member with respect to the rear frame of the vehicle body. Arranged,
A rear sub-frame structure for an automobile. Of the suspension links provided in the multilink type rear suspension device, the vehicle body side ends of a pair of left and right lateral links extending in the vehicle width direction from the vehicle body side toward the wheel side are attached to the first attachment portion. And
Among the suspension links provided in the multi-link type rear suspension device, the second attachment portion includes ends of a pair of left and right leading links extending forwardly forward from the vehicle body side toward the wheel side toward the vehicle body side. The rear sub-frame structure for an automobile according to claim 1, wherein the portion is attached.

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