JP6003301B2 - Subframe structure of automobile - Google Patents

Description

  The present invention relates to a sub-frame structure for an automobile that is installed under a pair of left and right front side frames or rear side frames that extend to the front side or rear side of a passenger compartment.

  Generally, a subframe is provided below the left and right side frames provided on the front side or rear side of the passenger compartment, and a suspension arm is supported by the subframe. doing.

  Conventionally, in the above-mentioned subframe, in order to increase the support rigidity of the suspension arm in the normal state (particularly, the rigidity with respect to the load in the vehicle width direction during turning), the rigidity of the subframe itself and the body attachment rigidity of the subframe are increased. It is requested. However, at the time of a vehicle collision, there is a contradictory need to easily deform the subframe for the purpose of absorbing the load and to smoothly remove the subframe from the vehicle body.

  In Patent Document 1 below, in order to meet the need to increase the support rigidity of the suspension arm, a pipe material that is substantially U-shaped in plan view and a connection that connects the left and right sides of the U-shaped pipe material. A vehicle suspension system provided with a front subframe comprising a member (cross member) and a transmission means comprising two pipe members arranged in a substantially V shape in plan view with respect to the U-shaped pipe member. And configured to transmit the load input from the suspension arm to the front subframe to the mounting portion provided on the vehicle body side member via the transmission means, thereby increasing the mounting rigidity of the suspension arm, and An improved torsional rigidity is disclosed.

  In Patent Document 2 below, the suspension members (subframes) are changed to the left and right front side members (sideframes) in order to meet the need for easily deforming the subframes and smoothly removing the subframes from the vehicle body. There is disclosed a configuration in which a rear supporting portion to be coupled is configured to be deformable by inputting a predetermined or more collision load.

  Further, in Patent Document 3 below, the fastening member that fastens the front side member (side frame) and the sub frame can be moved to the front side member so that the fastening member can move to the rear rear side when a collision load exceeding a predetermined value is input. What formed the frame movement control means (a long hole, a through-hole) is disclosed.

  In addition, Japanese Patent Application Laid-Open Publication No. 2004-228561 discloses a structure in which the support rigidity of the attachment member that connects the front side frame (side frame) and the suspension cross member (subframe) is partially set low. In Patent Document 4, it is possible to disconnect the attachment member by generating a three-dimensional twist in the attachment member at the time of a frontal collision of the vehicle. Finally, the suspension cross member is attached to the front side. It can be detached from the frame.

JP 2009-61879 A JP-A-9-315338 Japanese Patent Laid-Open No. 2004-130827 JP 2011-162159 A

  In Patent Document 1, the rigidity of the subframe is increased by configuring the subframe with a transmission means made of a pipe material or a U-shaped pipe material, but the subframe is deformed for the purpose of load absorption at the time of a vehicle collision. Further, there is no disclosure about the technical idea of detachment, and the rear part of the relatively thick U-shaped pipe material extends in the vehicle width direction, which is disadvantageous in terms of the exhaust pipe layout.

  In Patent Documents 2 and 3, the suspension member and the subframe at the time of a vehicle collision are made weak by weakening a part of the suspension member (back support part) and a part of the front side member (subframe movement control means). Can be detached from the vehicle body, but on the other hand, the vehicle body mounting rigidity of the suspension member and subframe, that is, the rigidity against the load in the vehicle width direction during normal times (especially during turning) is insufficient. There was a problem of becoming.

  Therefore, it is conceivable to adopt only the conventional technique disclosed in Patent Document 4 without adopting the conventional techniques disclosed in Patent Documents 2 and 3, but in this case, if the vehicle body mounting rigidity is high, In the event of a vehicle collision, it becomes difficult to smoothly deform and disengage the suspension member and the subframe, and there is a concern that load absorption at the time of the collision will be insufficient.

  Accordingly, the present invention provides a left and right side member in which the subframe extends in the vehicle front-rear direction, a cross member that is connected to the vehicle interior side end portion of these side members and extends in the vehicle width direction, and a side member connection of the cross member An extension portion extending outward in the vehicle width direction from the first portion, a first vehicle body attachment portion provided at an outer end portion of the extension portion of the cross member and attached to the vehicle body, the extension portion of the cross member, and the side member And an arm support portion that supports the arm of the suspension, and the arm support portion is connected between the side member connecting portion of the cross member and the first vehicle body mounting portion. The connecting portion with the support portion is made weaker in the vehicle front-rear direction than the portion in the vehicle width direction with respect to the connecting portion, thereby making the cross member in the vehicle width direction central portion highly rigid. In addition, the connection part of the cross member with the arm support part is fragile, but this is reinforced by the arm support part to ensure the connection rigidity of the left and right side members and the rigidity around the first vehicle body mounting part in normal times. On the other hand, at the time of a collision in the front-rear direction, even if the first vehicle body mounting part is not detached due to the transmission load (stress concentration) from the side member and the arm support part at the connection part of the cross member with the arm support part, An object of the present invention is to provide a subframe structure for an automobile in which the extended portion is crushed in the front-rear direction so that the side member can be easily moved toward the passenger compartment, and the collision load peak can be reduced.

A subframe structure for an automobile according to the present invention is a subframe structure for an automobile that is installed under a pair of left and right side frames that extend to the front side or the rear side of a passenger compartment. Left and right side members extending, a cross member connected to the vehicle compartment side ends of the left and right side members and extending in the vehicle width direction, and an extending portion extending outward from the side member connecting portion of the cross member in the vehicle width direction The suspension member is provided at the outer end of the extending portion of the cross member, and is connected to the first vehicle body attaching portion attached to the vehicle body, the extending portion of the cross member, and the side member to support the arm of the suspension. An arm support portion, and the arm support portion is connected between the side member connecting portion of the cross member and the first vehicle body mounting portion, and Connecting portion between the arm support portion of the member, is vulnerable in the longitudinal direction of the vehicle than the portion in the vehicle width direction center side with respect to the connecting portion, the arm support consists of upper bracket and the lower bracket, at least one of A connecting portion of the bracket to the extending portion of the cross member is separated from the first vehicle body mounting portion, and the other bracket is connected to the first vehicle body mounting portion directly or to an extending portion in the vicinity .
The above-described side frame can be a front side frame when the present invention is applied to the front side, and can be a rear side frame when the present invention is applied to the rear side.

According to the above configuration, the central part of the cross member in the vehicle width direction is highly rigid, and the connecting part of the cross member with the arm support part is fragile, but this is reinforced by the arm support part. Usually, the connection rigidity of the left and right side members and the rigidity around the first vehicle body mounting portion can be ensured.
In addition, when the automobile collides in the front-rear direction, the first vehicle body attachment portion does not come off due to the transmission load (stress concentration) from the side member and the arm support portion at the connection portion of the cross member with the arm support portion. However, the extending portion (the weakened portion) of the cross member is crushed in the front-rear direction, whereby the side member can be easily moved in the direction of the passenger compartment, and the collision load peak can be reduced.

In addition, the arm support portion is composed of an upper bracket and a lower bracket, a connecting portion between at least one bracket and the extending portion of the cross member is separated from the first vehicle body mounting portion, and the other bracket is the first vehicle body. since those linked directly or the extended portion in the vicinity of the mounting portion, the suspension and the supporting rigidity ensures the arms of the normal, and the mounting rigidity ensuring subframe, and a deformation promoting the collision, the upper and lower Easy adjustment with brackets (upper bracket and lower bracket).

In an embodiment of the present invention, a second vehicle body attachment portion that is detachable by receiving a load in the front-rear direction is connected in the vicinity of the side member connection portion of the cross member.
It is preferable that the second vehicle body mounting portion and the first vehicle body mounting portion are arranged in a substantially straight line in the vehicle width direction.

  According to the above configuration, since the second vehicle body mounting portion is provided in addition to the first vehicle body mounting portion, both the first vehicle body mounting portion and the second vehicle body mounting portion improve the normal mounting rigidity. Crushing the extended portion of the cross member that has become brittle due to the collision load from the side member, reducing the load transmission to the first vehicle body mounting portion, and then concentrating the stress on the second vehicle body mounting portion. The load can be effectively transmitted to the two vehicle body mounting portions, and the second vehicle body mounting portion can be detached.

In an embodiment of the present invention, a third vehicle body attachment portion that can be detached by a longitudinal displacement is provided at an outer portion in the longitudinal direction of the side member.
When the present invention is applied to the front side, the aforementioned front-rear outer portion means the front portion in the front-rear direction, and when the present invention is applied to the rear side, it means the rear portion in the front-rear direction. To do.

According to the above configuration, the third vehicle body attachment portion can be detached without removing the first vehicle body attachment portion. Further, when the side member moves in the vehicle front-rear direction, the third vehicle body attachment portion is detached, thereby reducing load distribution and stress is concentrated on the vehicle compartment side member, so that the vehicle body attachment portion on the vehicle compartment side (first vehicle body attachment portion) or the second vehicle body mounting portion) may turn easily separated.

  In one embodiment of the present invention, the arm support portion is directly connected to the lower portion of the first vehicle body mounting portion or connected to the lower portion of the extending portion of the cross member in the vicinity thereof.

  According to the above configuration, the collision load is transmitted to the lower part of the first vehicle body attachment part or the lower part of the cross member extension part in the vicinity thereof by the arm support part at the time of a collision. By twisting in the pulling direction, it is possible to promote the detachment.

In one embodiment of the present invention, the connecting portion of the cross member with the arm support portion is weakened by making the connecting portion thinner than a portion on the center side in the vehicle width direction with respect to the connecting portion. .
The weakened structure due to the thin wall described above may be weakened by a member having a smaller wall thickness by a tailored blank, a pipe having a smaller wall thickness in a connection structure by welding or bonding of pipes having different wall thicknesses.
According to the said structure, it can achieve by making the weak structure of a connection part with the arm support part of a cross member thin.

In one embodiment of the present invention, the connecting portion of the cross member with the arm support portion is weakened by being a bent portion.
According to the said structure, it can achieve by making the weak structure of a connection part with the arm support part of a cross member into a bending part.

  According to the present invention, the sub-frame has left and right side members extending in the vehicle front-rear direction, a cross member connected to the vehicle interior side end portion of these side members and extending in the vehicle width direction, and a side member connection of the cross member An extension portion extending outward in the vehicle width direction from the first portion, a first vehicle body attachment portion provided at an outer end portion of the extension portion of the cross member and attached to the vehicle body, the extension portion of the cross member, and the side member And an arm support portion that supports the arm of the suspension, and the arm support portion is connected between the side member connecting portion of the cross member and the first vehicle body mounting portion. Since the connecting portion with the support portion is weaker in the vehicle longitudinal direction than the portion on the center side in the vehicle width direction relative to the connecting portion, the center portion in the vehicle width direction of the cross member is made highly rigid. Although the connecting part of the cross member with the arm support part is fragile, it is reinforced by the arm support part, and normally the connection rigidity of the left and right side members and the rigidity around the first vehicle body mounting part are secured. In the case of a collision in the front-rear direction, the extension of the cross member does not occur due to the transmission load (stress concentration) from the side member and the arm support portion at the connection portion of the cross member with the arm support portion even if the first vehicle body attachment portion does not come off. Since the installation portion is crushed in the front-rear direction, the side member can easily move toward the passenger compartment, and the impact load peak can be reduced.

The side view which shows the sub-frame structure of the motor vehicle of this invention Bottom view of subframe structure Plan view showing subframe structure Bottom view of FIG. Perspective view showing subframe structure as viewed from obliquely above A perspective view showing the subframe structure as viewed from obliquely below 3 is a cross-sectional view taken along line AA in FIG. BB cross-sectional view of FIG. Expanded cross-sectional view of the main part showing the mount mounting part CC sectional view taken on line CC in FIG. FIG. 5 is an enlarged perspective view of the main part of FIG. Perspective view at the time of collision (front collision) load input Plan view at the time of collision (front collision) load input Bottom view when a collision (front collision) load is input Side view showing another embodiment of subframe structure of automobile The bottom view of the sub-frame structure of FIG. Perspective view showing subframe structure Exploded perspective view of subframe structure Partial enlarged perspective view of FIG. The perspective view shown in the state which looked up at the vehicle body attachment part periphery structure shown in FIG. 19 from the downward direction A sectional view taken along line D-D in FIG. 17 is a cross-sectional view taken along line EE in FIG. 17 is a cross-sectional view taken along line GG in FIG. A bottom view showing still another embodiment of the sub-frame structure of the automobile Fig. 4 shows still another embodiment of the sub-frame structure of an automobile, (a) is a partial plan view showing another embodiment of the fragile structure, and (b) is a partial plan view showing still another embodiment of the fragile structure.

The central part of the cross member in the vehicle width direction has high rigidity, and the brittle structure of the connection part of the cross member with the arm support part is reinforced by the arm support part. The first vehicle body mounting portion is secured by the transmission load (stress concentration) from the side member and the arm support portion to the connecting portion of the cross member with the arm support portion at the time of a collision in the front-rear direction while ensuring the rigidity around the vehicle body mounting portion. Even if the detachment of the cross member does not occur, the extension of the cross member is crushed in the front-rear direction, and the side member can be easily moved in the direction of the passenger compartment. It is a subframe structure of an automobile that is installed under a pair of left and right side frames that extend to the rear side, and the subframe includes left and right side members that extend in the vehicle front-rear direction, A cross member connected to the compartment side end of the left and right side members and extending in the vehicle width direction, an extending portion extending outward from the side member connecting portion of the cross member in the vehicle width direction, and an extension of the cross member A first vehicle body mounting portion that is provided at an outer end portion of the portion and is attached to the vehicle body; and an arm support portion that is connected to the extending portion of the cross member and the side member and supports the arm of the suspension. The arm support portion is connected between the side member connecting portion of the cross member and the first vehicle body mounting portion, and the connecting portion with the arm supporting portion of the cross member is connected to the connecting portion. is vulnerable in the longitudinal direction of the vehicle than the site of the center side in the vehicle width direction against, the arm support consists of upper bracket and the lower bracket, at least one of the brackets above Kurosume Connecting portion between the extending portion of the bar is spaced apart from the first vehicle body mounting portion, the other bracket is achieved in construction of Ru is connected to the extended portion of the direct or near the first vehicle body mounting portion.

An embodiment of the present invention will be described in detail with reference to the drawings.
In the following embodiments, a configuration in which a subframe structure of an automobile is applied to the front side will be described.
FIG. 1 is a side view showing a subframe structure of an automobile, and FIG. 2 is a bottom view of FIG. 1. In FIG. 1, a dash lower panel 1 (dash panel) that partitions an engine room and a vehicle compartment in the front-rear direction is provided. A floor panel 2 is integrally or integrally joined and fixed to the lower rear end of the dash lower panel 1.
The floor panel 2 described above is a panel member that forms the bottom surface of the passenger compartment, and extends substantially horizontally from the lower rear end of the dash lower panel 1 toward the rear. A tunnel portion 3 (floor tunnel) that protrudes into the vehicle interior and extends in the front-rear direction of the vehicle is integrally or integrally formed at the center of the lower panel 2 in the vehicle width direction.

As shown in a bottom view in FIG. 2, a pair of left and right tunnel members 4, 4 extending in the front-rear direction of the vehicle are provided along the lower edge of the tunnel portion 3, and the tunnel member 4 having a hat-shaped cross section is provided on the floor panel 2 described above. A closed cross section extending in the front-rear direction is formed between the floor panel 2 and the tunnel member 4 by being bonded and fixed to the lower surface.
Side sills 5 and 5 are bonded and fixed to the left and right sides of the floor panel 2 described above.

The side sill 5 is a vehicle body strength member having a side sill closed section that extends in the front-rear direction of the vehicle by connecting upper and lower joint flange portions of the side sill inner and the side sill outer.
A floor frame 6 is provided at an intermediate portion in the vehicle width direction between the side sill 5 and the tunnel member 4 described above.
The floor frame 6 is a frame formed in a cross-sectional hat shape and extending in the front-rear direction of the vehicle. The floor frame 6 is joined and fixed to the lower surface of the floor panel 2, and the floor frame 6 is interposed between the floor panel 2 and the floor frame 6. A closed cross section extending in the front-rear direction of the vehicle is formed.

As shown in FIGS. 1 and 2, front side frames 7 and 7 are provided as a pair of left and right side frames having a closed cross-sectional structure that extends forward from the front portion of the dash lower panel 1 through the left and right sides of the engine room. .
A kick-up portion 7a is integrally formed at the rear portion of the front side frame 7 along the front and lower surfaces of the dash lower panel 1, and the front side frame 7 and the floor frame 6 are arranged in the front-rear direction of the vehicle. It is formed to be continuous.

As shown in FIG. 1, a crash can 10 (impact energy absorbing member) is connected to front ends of front side frames 7 and 7 as a pair of left and right side frames via flanges 8 and 9, respectively. As shown in FIG. 2, a bumper rain 11 extending in the vehicle width direction is attached between the front ends of the pair of left and right crash cans 10, 10.
In FIG. 2, 12 is a suspension tower, 13 is an apron rain, and 14 is a plate-shaped tunnel cross member that connects a pair of left and right tunnel members 4 and 4 in the vehicle width direction.

3 is a plan view of the subframe (consent with the suspension cross member), FIG. 4 is a bottom view of the subframe, FIG. 5 is a perspective view of the subframe as viewed from obliquely above, and FIG. 6 is obliquely below the subframe. It is a perspective view shown in the state looked up from.
As shown in FIGS. 1 and 2, a sub-frame 20 shown in FIGS. 3 to 6 is installed below the pair of left and right front side frames 7 and 7 provided at the front portion of the vehicle body.

As shown in FIGS. 3 to 6, the above-described subframe 20 includes a pair of side members 21 </ b> F and 21 </ b> R that are formed in a tubular shape that extends in the vehicle front-rear direction, that is, a pipe.
Left and right vehicle body attachment portions 22 (upwardly extending from the front and rear side members 21F and 21R (intermediate portion of the side members) and connected to the left and right front side frames 7 and 7 shown in FIGS. A so-called “horn member”, hereinafter simply abbreviated as a tower section),
A front cross member 23 (so-called No. 0 cross member) erected in the vehicle width direction between the pair of left and right side members 21F, 21F on the front side;
A center cross member 24 erected in the vehicle width direction between the front portions of the pair of left and right side members 21R, 21R on the rear side;
An inclined member 25 (so-called V-shaped) as a cross member laid in a substantially V shape in a plan view between the center portion in the rear vehicle width direction of the center cross member 24 and the rear end portion of the rear side member 21R. Braces)
A rear cross member 26 constructed to extend in the vehicle width direction between the left and right rear portions of the inclined member 25 corresponding to the rear end of the rear side member 21R;
It has.
The above-described inclined member 25 is a cross member that is connected to the cabin side ends of the left and right side members 21F and 21R and extends in the vehicle width direction.

  As shown in FIG. 5 and FIG. A front mount portion M1 (specifically, a mount pipe and a mount bush) as one mount portion is connected, and a No. A center mount part M2 (mount pipe constituting the third vehicle body attachment part) as a second mount part is connected, and a No. A rear mount portion M4 (mount pipe constituting the first vehicle body attachment portion) is connected as a 4-mount portion, and inside mount portions M3 constituting the second vehicle body attachment portion are set on the left and right sides of the rear cross member 26. doing.

1 and 2, a pair of left and right front mount portions M1, M1 are connected to the front lower surface of the front side frame 7, and a pair of left and right center mount portions M2, M2 are connected to the front and rear of the front side frame 7. A pair of left and right rear mounts M4 and M4 are connected to the rear lower surface of the front side frame 7, and a pair of left and right inside mounts M3 and M3 are connected to the front lower surface of the tunnel member 4. Yes.
That is, the subframe 20 is mounted on the vehicle body at four points on one side and a total of eight points on both the left and right sides.
Here, the inside mount parts M3 and M3 and the rear mount parts M4 and M4 described above are arranged so as to be aligned substantially in a straight line in the vehicle width direction, as shown in FIGS.

As shown in FIGS. 5 and 6, the front side member 21F is formed by hydroforming a square metal pipe into a square frame shape, and the side member 21F has a closed cross section extending in the longitudinal direction of the vehicle. Is formed.
The rear side member 21R is formed of a metal round pipe, and the side member 21R also has a closed cross section extending in the front-rear direction of the vehicle.
Furthermore, the above-mentioned front cross member 23 is formed by processing a metal square pipe, and the front cross member 23 has a closed cross section extending in the vehicle width direction.

A resin-made jack retainer 27 is attached to the lower portion of the front cross member 23 in the vehicle width direction. The jack retainer 27 can be used as a jack-up point when the vehicle is jacked up.
As shown in FIGS. 1 and 2, a sub-crash can 30 is attached to the front end portion of the above-mentioned front side member 21 </ b> F via flanges 28 and 29. The sub crush can 30 at the front end of the side member 21F and the crush can 10 at the front end of the front side frame 7 are both shock absorbing members.
The above-described center cross member 24 connects the left and right side members 21R, and joins and fixes a center cross member upper 24a having a substantially hat-shaped cross section and a center cross member lower 24b located on the lower side, so that the vehicle width direction A closed cross section 24c (see FIG. 8) is formed. An opening 24d for a power train mount 50, which will be described later, is formed on the center front surface of the center cross member 24 in the vehicle width direction, and the center cross member upper 24a, the center cross described above is formed corresponding to the opening 24d. The member lower 24b is integrally formed with rear bulges 24e and 24e that bulge toward the rear of the vehicle from the rear edges of the left and right side portions at the center in the vehicle width direction of the center cross member 24, and these upper and lower rear bulges 24e. 24e is connected to the center of the front portion of the inclined member 25 (see FIG. 1).
A pair of left and right openings S are formed between the center cross member 24, the inclined member 25, and the side member 21R.

As shown in FIGS. 3 and 4, the rear bulging portion 24e described above protrudes in a substantially trapezoidal shape toward the rear of the vehicle, and left and right outer shells of the rear bulging portion 24e extend in the vehicle front-rear direction. Inclined vertical wall portions 24e1 and 24e1 are formed. Then, the rear inclined wall of the rear bulge portion 24e and the inclined member 25 are connected in the front-rear direction by a pair of left and right braces 31, 31 made of a square pipe and having a closed sectional structure.
In this embodiment, the mount attachment portion 51 for the power train mount 50 is disposed behind the front edge of the center cross member 24 and ahead of the inclined member 25. Is constituted by rear bulges 24e, 24e.
The inclined member 25 as the cross member described above extends in the vehicle width direction behind the front cross member 23 (in the vehicle compartment side), thereby constituting a vehicle compartment side cross member, and the rear mount portion M4. , M4.
The inclined member 25 is a closed cross-section structural member formed by processing a metal square pipe, and the inclined member 25 is located on the front side and extends in the vehicle width direction as shown in FIGS. A central portion 25a, an inclined portion 25b that extends inward in the vehicle width direction toward the central portion 25a and forward (outward in the front-rear direction opposite to the passenger compartment), and outward in the vehicle width direction from the rear end of the inclined portion 25b The extending rear portion 25c is integrally formed.

As shown in FIGS. 3 and 4, the rear side member 21 </ b> R extends forward from the inclined member 25, and its rear end is abutted against and connected to the rear front surface of the inclined portion 25 b of the inclined member 25. Yes.
The above-described rear mount portion M4 is disposed at a position spaced apart from the connecting portion X (side member connecting portion of the inclined member 25) where the inclined member 25 is connected to the side member 21R in the vehicle width direction. The above-described inside mount portion M3 is set at a position opposite to the portion X.
An extending contact portion 25d extending outward in the vehicle width direction from the side member connecting portion X of the inclined member 25 to the outer end portion in the vehicle width direction of the rear portion 25c is provided, and the rear portion 25c at the outer end portion of the extending portion 25d is provided on the rear portion 25c. The above-described rear mount portion M4 as the first vehicle body attachment portion is disposed.

Further, between the extended portion 25d of the inclined member 25 and the above-mentioned side member 21R, an arm support portion for supporting the rear side of the lower arm 40 (see FIG. 5) as a suspension arm from the upper side and the lower side, respectively. The upper bracket 32 and the lower bracket 33 are attached. The upper and lower upper brackets 32 and the lower bracket 33 are integrally formed with concave and convex portions such as beads, and the rigidity of the brackets 32 and 33 themselves is increased. Yes.
Here, the upper bracket 32 positioned on the upper side is formed in a substantially triangular shape having a relatively small area when viewed from the plane, and the lower bracket 33 positioned on the lower side is a relatively large area when viewed from the plane. It is formed in a substantially fan shape.

As shown in FIGS. 3, 11, and 13, the upper bracket 32 and the lower bracket 33 described above are connected at least between the side member connecting portion X of the inclined member 25 and the rear mount portion M4.
Specifically, as shown in FIGS. 3, 11, and 13, the upper bracket 32 as one bracket has a front end connected to the side member 21 </ b> R and a rear end extending from the rear mount portion M <b> 4 on the outer side in the vehicle width direction. It is separated from the inside in the vehicle width direction and connected to the extending portion 25d.
That is, the connecting portion Y of the upper bracket 32 and the extending portion 25d of the inclined member 25 is separated from the rear mount portion M4 as the first vehicle body attachment portion.

As shown in FIGS. 4, 11, and 13, the lower bracket 33 as the other bracket has a front end connected to the side member 21R and a rear end extending directly or near the rear mount M4. It is connected to the portion 25d. In this embodiment, the rear end of the lower bracket 33 is connected to the extending portion 25d in the vicinity of the rear mount portion M4.
Furthermore, the rear end of the lower bracket 33 described above is directly connected to the lower part of the rear mount part M4 or connected to the lower part of the extending part 25d of the inclined member 25 in the vicinity thereof. In this embodiment, as shown in FIG. 4, the rear end of the lower bracket 33 is connected to the lower portion of the extending portion 25d, specifically to the lower portion of the rear portion 25c, in the vicinity of the rear mount portion M4.

Here, the above-described inside mount portion M3 as the second vehicle body attachment portion is provided on the rear cross member 26 in the vicinity of the side member connecting portion X of the inclined member 25, and receives the load in the vehicle longitudinal direction. It is configured to be able to leave.
Further, the center mount portion M2 as the third vehicle body mounting portion described above is provided on the outer side in the front-rear direction of the side members 21F, 21R (in this embodiment, the front-rear front side portion). The tower portion 22 is provided so as to be detachable from the center mount portion M2.

As shown in FIGS. 3 and 4, the above-mentioned rear cross member 26 is made of sheet metal and has a gate-shaped rear cross member upper 26a, and at the lower part of the rear cross member upper 26a, on the left and right outer sides in the vehicle width direction. The rear cross member lowers 26b and 26b are fixed to each other, and the rear cross member upper 26a located on the upper side is located between the left and right extending portions 25d and 25d of the inclined member 25 as viewed from the above. And is constructed in the vehicle width direction so as to be substantially straight.
The above-described inside mount portions M3 and M3 are set on the rear cross member 26 at both ends in the vehicle width direction.

  7 is a cross-sectional view of the vehicle on the right side along the line AA in FIG. 3, FIG. 8 is a cross-sectional view of the vehicle on the right side along the line BB in FIG. As shown in FIGS. 7 and 8, a U-shaped cross section mounting bracket upper 22a and a mounting bracket lower 22b joined and fixed to the mounting bracket upper 22a are provided. It is arrange | positioned in the position spaced apart ahead rather than the center part.

As shown in FIG. 8, the above-described tower portion 22 has a closed cross section 22c that extends at the vehicle width direction outer side and upward from the lower surface of the side members 21F and 21R including at least the lower portion thereof.
In this embodiment, the above-described closed cross section 22c extends obliquely upward and outward of the vehicle, and the lower portion of the closed cross section 22c extending obliquely upward and outward of the vehicle supports the front side of the lower arm 40 (see FIG. 5). The lower arm support portions 22d and 22e (see FIG. 4) are provided, and the lower surface portion 22f at the lower end thereof is connected to the center cross member lower 24b of the center cross member 24 as shown in FIG. As a result, the input load from the lower arm 40 (particularly the lateral load when the vehicle turns, etc.) is distributed to the front side frame 7 and the input load is smoothly transmitted to the center cross member 24 so as to distribute the load. It is composed. Here, the front and rear lower arm support portions 22d and 22e described above are formed so as to protrude downward relative to the mount bracket lower 22b, and this raised structure increases the strength of the lower arm support portions 22d and 22e themselves. ing.

As shown in FIG. 5, the lower portion of the above-described tower portion 22 is formed in a substantially box shape, and a portion extending upward from the box shape portion is formed in a horn shape. Further, the side member is divided into a front side member 21F and a rear side member 21R in the front and rear direction, and the rear end of the front side member 21F is the tower portion 22 as shown in FIGS. The front side of the rear side member 21R is connected to the front surface of the substantially box-shaped part, and the front end of the rear side member 21R is connected to the rear surface of the substantially box-shaped part of the tower part 22 so that the closed cross section of the side members 21F and 21R is not crushed when a load is input The load is transmitted to the center cross member 24 to distribute the load.
In other words, the front and rear side members 21 </ b> F and 21 </ b> R are configured to be continuous in the front-rear direction of the vehicle via the substantially box-shaped portion of the closed section structure of the tower portion 22.

  As shown in FIGS. 7 and 8, the lower arm support portions 22d and 22e of the tower portion 22 described above are formed on the outer surface in the vehicle width direction, and the support bracket 41 of the lower arm 40 is fastened with bolts 42, nuts 43, and the like. Assembling property when supporting the lower arm support portions 22d and 22e using the members is ensured, and the closed section 22c of the tower portion 22 is smoothly formed between the front side frame 7 and the side members 21F and 21R. It is configured.

Further, as shown in FIG. 8, the mount bracket lower 22b located on the outer side surface in the vehicle width direction of the tower portion 22 in the vehicle width direction outer side portion, that is, the mount bracket upper 22a and the mount bracket lower 22b, is provided on the side member 21F. , 21R and the front side frame 7 so as to incline substantially linearly so as to improve the lateral load dispersion performance.
Further, as shown in FIGS. 6, 7, and 8, the lower arm support portions 22d and 22e of the tower portion 22 have a closed cross section 22c that branches substantially back and forth, and a front support portion 22d, a rear support portion 22e, And the rigidity of the lower arm support portions 22d and 22e is increased by the above-described closed section 22c itself, thereby improving the support rigidity of the lower arm 40.

  3 and 8, at the position where the center cross member 24 and the tower portion 22 overlap in the vehicle front-rear direction, a horizontal portion 22h is partially formed on the upper surface portion 22g of the lower portion of the tower portion 22, Fastening members such as bolts 34 and nuts 35 are used for the horizontal portion 22h so that the front portions of the stabilizer support brackets 36 and 37 as auxiliary machine mounting brackets are attached.

As shown in a perspective view in FIG. 5, the lower stabilizer support bracket 36 is formed in a flat plate shape, and the upper stabilizer support bracket 37 is formed in a substantially Ω shape, and these upper and lower stabilizer support brackets are formed. 36 and 37 support a stabilizer (not shown) as an auxiliary machine.
As is well known, the stabilizer suppresses the roll angle at the time of rebound and bump of only one wheel by resistance of torsional rigidity.

As shown in FIGS. 3 and 4, the side member 21 </ b> R is provided with a stabilizer mounting bush 45 and a steering rack mounting bush 46 spaced apart in the front-rear direction. Each of these bushes 45 and 46 is formed of a rigid pipe that connects the upper and lower surfaces of the side member 21R by welding.
Here, the stabilizer support brackets 36 and 37 are attached to the stabilizer mounting bush 45 using fastening members such as bolts and nuts as in FIG. 8 (see FIG. 5).

  As shown in FIG. 8, the upper surface portion 22g of the lower portion of the tower portion 22 including the horizontal portion 22h is connected to the center cross member 24, and the collapse of the closed cross sections of the side members 21F and 21R is further improved. In addition to preventing this, the coupling strength of the tower portion 22 to the center cross member 24 is improved.

  As shown in FIG. 4, the center cross member 24 has at least one of the front support portion 22d and the rear support portion 22e of the tower portion 22 in the entire length in the vehicle width direction, and in this embodiment, the rear support portion. 22e is disposed rearwardly from the tower portion 22 so that the vehicle front-rear position overlaps, ensuring a vehicle width direction load transmission path, and a front engine type powertrain PT comprising an automobile engine or a drive motor. (See FIG. 3 and FIG. 4).

As shown in FIGS. 3 and 5, the center cross member 24 is extended with its left and right end portions inclined in the vehicle longitudinal direction toward the mount portion side of the tower portion 22, specifically toward the front lower arm support portion 22 d side. As a result, an extension 24f extending obliquely outward and forward is formed, and as shown in FIG. 4, the mount bracket lower 22b of the tower 20 has an inner portion in the vehicle width direction in the center of the vehicle in the longitudinal direction. An extension portion 22j extending obliquely to the front side of both side portions of the member 24 is integrally formed. The extension portion 22j is connected to the center cross member 24, and is intermediate in the vehicle width direction on the opposite side in the vehicle front-rear direction (that is, the rear side). The inclined member 25 is connected to the portion.
In the inclined member 25, the inclined portion 25b extends from the rear rear mount portion M4 in plan view toward the lower arm support portions 22d and 22e on the opposite side in the vehicle width direction.

  With this configuration, load transmission paths in the vehicle width direction and the inclination direction are secured.

That is, as indicated by the solid arrow α1 in FIGS. 3 and 4, when a load is input from the right lower arm support portion 22d, the load is transmitted from the extension portion 22j to the center cross member 24, and then a part of the load is transmitted. 3 and 4, the vehicle is transmitted in the vehicle width direction along the front edge of the center cross member 24, and at the same time, as shown by the solid line arrow α 3, the center cross member 24 is inclined to the inclined member. 25 can also be branched and transmitted to the left inclined portion 25b.
Conversely, when a load is input from the left lower arm support portion 22d, the load is transmitted from the extension portion 22j to the center cross member 24 as shown by a dotted arrow β1 in FIGS. Is transmitted in the vehicle width direction along the front edge of the center cross member 24 as shown by a dotted arrow β2 in FIGS. 3 and 4, and at the same time, tilted from the center cross member 24 as shown by a dotted arrow β3 It can also be branched and transmitted to the right inclined portion 25b of the member 25.
As a result, the load transmission path from the left and right lower arm support portions 22d and 22e transmits the load in the vehicle width direction along the center cross member 24 (arrows α2 and β2) and the inclined member via the center cross member 24. Inclination direction load transmission paths (arrows α3, β3) for transmitting 25 in a substantially X shape in plan view can be secured.

  In particular, in this embodiment, the center mount portion M2 (so-called No. 2 mount portion) of the tower portion 22, the lower arm support portion 22e on the rear side, and the front portion of the center cross member 24 are substantially straight in the vehicle width direction. By arranging, the above-described vehicle width direction load transmission path is formed. Thus, the installation space for the mount mounting portion 51 is secured behind the front edge of the center cross member 24, and the layout of the power train PT is secured, while the load is input from the lower arm support portions 22d and 22e in the vehicle width direction. The load is smoothly transmitted.

Specifically, the vehicle width direction load transmission path (arrows α2 and β2) and the inclination direction load transmission path (arrows α3 and β3) described above are formed at the time of load input, so that the front edge of the center cross member 24 A low-stress part where the load transmission path is not formed is formed at the rear center part in the vehicle width direction.
In this embodiment, the mount mounting portion 51 is disposed in the low stress portion so as to avoid the load transmission path. Thereby, the power train mount 50 can be compactly disposed on the center cross member 24 while preventing the influence of the load from reaching the power train mount 50 provided at the center of the rear surface of the power train PT. As a result, the layout of the powertrain PT is ensured.

  9 is an enlarged cross-sectional view of the main part showing the mount mounting portion, and FIG. 10 is a cross-sectional view taken along the line C-C of FIG. 9, and in the rear bulge portion 24e of the center cross member 24, FIG. 9 and 10, internal partition walls 52, 52 comprising vertical walls extending in the front-rear direction are provided on the left and right sides of the mount mounting portion 51, and the front and rear ends of the internal partition walls 52, 52 are respectively center cross members. 24 are connected to the front and rear surfaces. The braces 31, 31 described above are disposed at the rear positions corresponding to the left and right inner partition walls 52, 52, and the braces 31 are used to reinforce the rear portion of the rear bulge portion 24e (mount mounting portion 51). It is composed.

Further, in the mount mounting portion 51, the above-described opening 24d has imaginary lines L and L that connect the left and right ends of the front edge of the center cross member 24 and the connecting portion of the inclined member 25 (see the one-dot chain line in FIG. 2). ) At a position that does not cross the rear edge and is spaced rearward and downward from the front edge.
Further, on the front surface of the center cross member 24, a bypass path 24g extending in the vehicle width direction and bypassing the front edge is disposed on the opposite side of the front edge across the opening 24d.

With this configuration, the load in the vehicle width direction is transmitted in the vehicle width direction along the front edge in front of the opening 24d, as shown by the solid arrow α21 and the dotted arrow β21 in FIG. As shown by the solid line arrow α22 and the broken line arrow β22 in FIG. 3, the light is branched from the front edge and transmitted to the bypass path 24g.
On the other hand, the load in the tilt direction is transmitted to the tilt member 25 through the vertical wall portions 24e1 and 24e1 of the rear bulge portion 24e as shown by the solid arrow α31 and the dotted arrow β31 in FIG. As shown by a solid line arrow α32 and a broken line arrow β32 in FIG. 10, the light is transmitted to the inclined member 25 through the internal partition walls 52, 52.

By the way, the power train mount 50 has a cylindrical shape as shown in FIGS. 1, 5, 9, and 10, and the inner cylinder at the center of the power train mount 50 is fixed by fastening members such as bolts 53 and nuts 54. By being connected and fixed to the rear bulging portions 24e and 24e, the mounting portion 51 is mounted in the space (here, the space between the upper and lower rear bulging portions 24e and 24e). In the center cross member 24, the upper and lower rear bulge portions 24e and 24e are connected by bolts 53 and nuts 54 for attaching the power train mount 50, whereby the entire center cross member 24 including the rear bulge portion 24e is reinforced. It is configured.
In addition, a pair of links 55 are attached to the rear part of the power train PT, and the links 55 are inserted into the opening 24d and connected to the power train mount 50 inside the mount attaching part 51, whereby the power train. The rear part of PT is supported by the subframe 20.

  As shown in FIGS. 3 and 4, the rear ends of the center cross member 24 at both ends in the vehicle width direction overlap with the stabilizer mounting bushes 45 in the front-rear direction, and a stabilizer (not shown). The side member 21 </ b> R is prevented from being crushed while passing through in the vehicle width direction.

As shown in FIGS. 7 and 8, the connection structure between the center mount portion M2 and the tower portion 22 is as follows.
That is, the tower portion 22 is independently provided with an upper wall 22k and front and rear vertical walls 22m and 22m integrally formed with the mount bracket upper 22a, and a lower wall 22n integrally formed with the mount bracket lower 22b. Similarly to Patent Document 4, the upper wall 22k and the vertical walls 22m and 22m are welded to the center mount portion M2, while the lower wall 22n makes the center mount portion M2 non-welded and the base portions of the front and rear vertical walls 22m and 22m. Notch portions 22p and 22q are provided on the top and bottom, and the vehicle body mounting portion (tower portion 22) of the subframe 20 can be detached while leaving the center mount portion M2 in the vehicle body at the time of a frontal collision of the vehicle. The PT is configured to be allowed to recede.

11 is an enlarged perspective view of a main part of FIG. 5, FIG. 12 is a perspective view when a collision (front collision) load is input, and FIG. 13 is a plan view of the main part of FIG.
As shown in FIGS. 11 and 13, the upper bracket 32, which is one of the arm support portions including the upper bracket 32 and the lower bracket 33, has a curved end bent at the extending portion 25 d of the inclined member 25. It is connected to the upper part of the part 25e to constitute a connecting part Y.
Similarly, the lower bracket 33 is connected at the rear end thereof to the lower portion of the extending portion 25d including the bent portion 25e and the rear portion 25c of the inclined member 25, thereby constituting a connecting portion Y.
And as shown in FIG. 13, this connection part Y is made weaker than the site | part of the vehicle width direction center side with respect to this connection part Y in the vehicle front-back direction. However, the side member connecting portion X of the inclined member 25 is formed with high rigidity.

  In this embodiment, at the intermediate position between the side member connecting portion X of the inclined member 25 and the connecting portion Y of the inclined member 25 with the arm support portion, any bracket 32, 33 is attached to the extending portion 25d of the inclined member 25. A tailored seam T is formed in a portion that is not in contact with each other, the inner side in the vehicle width direction is thicker than the seam T, and the outer side in the vehicle width direction is thinner than the seam T. The connecting portion Y with the arm support portion is weakened with respect to a portion closer to the center in the vehicle width direction than that, and the connecting portion Y with the arm support portion of the inclined member 25 is made weak by forming a bent portion 25e. It is a thing. Further, a portion on the inner side in the vehicle width direction from the seam T described above is formed thick and highly rigid.

  Here, as is well known, the tailored blank manufacturing method is to make a pipe from a combination of plate materials having different thicknesses, and by setting the position of the above-mentioned tailored joint T as described above, the connecting portion Y can be weakened. Instead of this, pipes with different thicknesses are connected by welding or adhesion, etc., and the pipe with the smaller wall thickness is disposed corresponding to the connecting portion Y, and the pipe with the larger wall thickness is disposed on the side. The weakened structure may be formed by a portion having a small thickness by disposing the member connecting portion X and the inner portion in the vehicle width direction.

12, 13, and 14 are explanatory diagrams when a collision (front collision) load is input. When a collision load is input from the front of the vehicle during a vehicle collision (front collision), the front side frames 7 and 7 are displaced. At the same time, the sub-crash can 30 as an impact absorbing member is crushed in the front-rear direction as shown in FIG. 14 to absorb the impact (collision load).
On the side of the sub-frame 20 as a suspension cross member, a collision load is input from the side member 21R to the rear cross member 26 through the connecting portion X as shown by an arrow c1 in FIGS. As shown by an arrow c2, the collision load that is branched and input from the side member 21R to the upper bracket 32 is weakened from the connecting portion Y between the upper bracket 32 and the inclined member 25. Since this weak part is deformed by being input to the extended portion 25d, the side member 21R moves backward.
In this case, without detaching the inside mount portion M3 and the rear mount portion M4 from the vehicle body, the space between the mount portions M3 and M4 is crushed to increase the deformation in the vicinity thereof, thereby displacing the side member 21R rearward. It is.

As described above, when the side member 21R moves backward (relative movement with respect to the front side frame 7), the notch portions 22p and 22q are provided in the tower portion 22. In M2, a three-dimensional twist occurs.
Since the lower wall 22n and the center mount portion M2 are not welded, the lower portion of the center mount portion M2 is set to have lower rigidity than the side portion, the front portion, and the rear portion. Stress concentrates on the part, and the joint between the center mount part M2 and the tower part 22 is released.

  As described above, in the tower portion 22, the lower wall 22n is not welded to the center mount portion M2, and the notches 22p and 22q are provided above and below the base portions of the vertical walls 22m and 22m. , 21R can be displaced relative to the front side frame 7, the center mount portion M2 and the tower portion 22 can be disconnected and the vehicle body mounting portion (tower portion 22) can be detached from the front side frame 7. It has become. In other words, the lower wall 22n and the notches 22p and 22q of the tower portion 22 are displaced from the front side frame 7 by the side members 21F and 21R relative to the front side frame 7 so that the vehicle body mounting portion (tower portion 22 ) Is functioning as a detachable means capable of detaching.

In addition, the structure which makes a vehicle body attachment part (tower part 22) detach | leave by the relative displacement of the side members 21F and 21R is not necessarily limited to this. For example, the tower part 22 may be made of casting, and a notch part may be formed in a part thereof. In this case, the notch portion functions as a detaching means, and can be detached from the front side frame 7 by deformation of the tower portion 22 starting from the notch portion.
Further, a weak portion (notch, thin wall portion, etc.) is provided in the center mount portion M2 or a part of the fastening member that fastens the center mount portion M2 and the tower portion 22, and the tower is deformed or broken from the weak portion. The part 22 may be detached. In this case, the weak part provided in the center mount part M2 or the fastening member functions as a detaching means.
Further, the part from which the vehicle body attachment part (tower part 22) is detached by the operation of the detaching means is not necessarily limited to the intermediate part (tower part 22) corresponding to the center mount part M2, and corresponds to the front mount part M1. It may be the front part.

In this manner, when the tower portion 22 is detached from the center mount portion M2, a load is input from the side member 21R to the rear mount portion M4 and the inside mount portion M3. Since the load on M4 is smaller than the load on the inside mount portion M3, the twist of the inside mount portion M3 with the larger load transmission is expanded, and the inside mount portion M3 is mounted on the vehicle body due to the concentration of stress on the inside mount portion M3. It is pulled out from and leaves.
In this case, since the above-described side member connecting portion X is thick and highly rigid, the inside mount portion M3 can be efficiently twisted.
When the above-described inside mount portion M3 is pulled out and detached, stress concentrates on the rear mount portion M4, and the torsion of the rear mount portion M4 increases, and the rear mount portion M4 is detached from the vehicle body.

In this case, since the rear end of the lower bracket 33 is connected to the lower portion of the rear portion 25c (rear mount pipe M4) of the inclined member 25, the collision load causes the front side frame 7, the side members 21F and 21R, and the lower As shown by an arrow c3 in FIGS. 12 and 13, the signal is input to the lower portion of the rear portion 25c (rear mount pipe M4) through the bracket 33.
At this time, since the rear end of the upper bracket 32 is separated from the rear mount portion M4, the input collision load is smaller than the lower portion of the rear mount portion M4.
For this reason, when the collision load is biased and input to the lower part of the rear mount part M4, stress concentrates on the lower part of the rear mount part M4, and as shown by an arrow c4 in FIG. A torsional moment that displaces the lower part rearward is generated, and the rear portion 25c is twisted by the action of the torsional moment. Then, by the twist of the rear portion 25c, the rear mount portion M4 can be pulled out and detached from the front side frame 7.

  2, 4, 6, and 14, 22 x is a recess formed in the mount bracket lower 22 b to avoid interference with the lower arm 40, and in FIGS. 11, 12, and 13, 60 is a rear cross member. 26 is an opening for adjusting rigidity. In the figure, arrow F indicates the front of the vehicle, arrow R indicates the rear of the vehicle, arrow IN indicates the inward in the vehicle width direction, and arrow OUT indicates the outward in the vehicle width direction.

  As described above, the subframe structure of the automobile of the embodiment shown in FIGS. 1 to 14 is a subframe structure of the automobile constructed below the pair of left and right front side frames 7 extending on the front side of the passenger compartment. The sub-frame 20 includes left and right side members 21F and 21R extending in the vehicle front-rear direction, and cross members (inclined members) connected to the vehicle side end portions of the left and right side members 21F and 21R and extending in the vehicle width direction. 25), an extending portion 25d extending outward in the vehicle width direction from the side member connecting portion X of the cross member (inclined member 25), and an outer end portion of the extending portion 25d of the cross member (inclining member 25). A first vehicle body attachment portion (see rear mount portion M4) provided on the vehicle body, an extending portion 25d of the cross member (inclined member 25), and the side member 21R. And an arm support portion (see the upper bracket 32 and the lower bracket 33) coupled to support the suspension arm (see the lower arm 40 in FIG. 5), and the arm support portion (see the brackets 32 and 33). Is connected between the side member connecting portion X of the cross member (inclined member 25) and the first vehicle body mounting portion (rear mount portion M4), and the arm support portion of the cross member (inclined member 25). The connection part (refer to connection part Y) with each bracket 32 and 33 is made weaker in the vehicle front-rear direction than the central part in the vehicle width direction with respect to the connection part. (See FIGS. 2, 5, 11, and 13).

According to this configuration, the vehicle width direction central portion of the cross member (inclined member 25) (specifically, the side member connecting portion X including the side member connecting portion X) is highly rigid, and The connecting part (see connecting part Y) of the cross member (inclined member 25) to the arm supporting part (upper bracket 32, lower bracket 33) is fragile, but this is supported by the arm supporting part (see brackets 32 and 33). Since it is reinforced, the connection rigidity of the left and right side members 21F and 21R and the rigidity around the first vehicle body attachment portion (rear mount portion M4) can be ensured in normal times.
In addition, at the time of a collision in the front-rear direction of the automobile (at the time of the front collision in the above embodiment), a connecting portion (connecting portion Y) with the arm support portion (the brackets 32 and 33) in the cross member (inclined member 25) described above. Even if the first vehicle body mounting portion (rear mount portion M4) does not come off due to the transmission load (stress concentration) from the side members 21F and 21R and the arm support portion, the extended portion of the cross member (inclined member 25) 25d is crushed in the front-rear direction, whereby the side member 21R can be easily moved in the direction of the passenger compartment, and the peak of the collision load can be reduced.
In addition, a second vehicle body mounting portion (see the inside mount portion M3) that can be detached by receiving a load in the front-rear direction is connected to the cross member (see the inclined member 25) in the vicinity of the side member connecting portion X. Yes (see FIGS. 11 and 13).

According to this configuration, since the second vehicle body attachment portion (see the inside mount portion M3) is provided in addition to the first vehicle body attachment portion (see the rear mount portion M4), the first vehicle body attachment portion (rear mount portion M4) and The cross member (inclined member 25) that is weakened by a collision load from the side member 21R while improving the mounting rigidity of the sub-frame 20 in the normal state by using both the second vehicle body attachment portion (inside mount portion M3). The extension portion 25d is crushed and the load transmission to the first vehicle body attachment portion (rear mount portion M4) is reduced, and then stress is concentrated on the second vehicle body attachment portion (inside mount portion M3), and the second A load can be effectively transmitted to the vehicle body attachment portion (inside mount portion M3), and the second vehicle body attachment portion (inside mount portion M3) can be pulled out and detached from the vehicle body. Kill.
Further, a third vehicle body mounting portion (center mount portion M2) that can be detached by a longitudinal displacement is provided on the outer side in the longitudinal direction of the side members 21F and 21R (see FIGS. 5, 7, and 8). .

According to this configuration, the third vehicle body attachment portion (center mount portion M2) can be detached without removing the first vehicle body attachment portion (rear mount portion M4). However, in this embodiment, the tower portion 22 is detached while leaving the center mount portion M2 on the vehicle body side. Further, when the side member 21R moves in the vehicle front-rear direction (backward movement), the third vehicle body attachment portion (center mount portion M2) and the tower portion 22 are disconnected, thereby reducing load distribution and causing stress to be applied to the compartment side member. Thus, the vehicle body mounting portion (rear mount portion M4 or inside mount portion M3) on the vehicle compartment side is easily detached.
In addition, the arm support portion (see the brackets 32 and 33) includes an upper bracket 32 and a lower bracket 33, and the extended portion of the cross member (inclined member 25) of at least one bracket (see the upper bracket 32). A connecting portion to 25d (see the upper connecting portion Y of the upper and lower connecting portions Y, Y shown in FIG. 11) is separated from the first vehicle body mounting portion (see the rear mount portion M4), and the other bracket ( The lower bracket 33 (see FIG. 13) is connected to the first vehicle body attachment portion (see the rear mount portion M4) directly or in the vicinity of the extending portion 25d (see FIG. 13).

According to this configuration, the upper and lower brackets (the upper bracket 32 and the lower bracket 33) are used to ensure the supporting rigidity of the suspension arm (lower arm 40) in the normal state, the securing rigidity of the subframe 20, and the acceleration of deformation at the time of collision. ) Can be easily adjusted.
Further, the arm support portion (see the lower bracket 33) is directly connected to the lower portion of the first vehicle body attachment portion (see the rear mount portion M4), or the cross member (see the inclined member 25) is extended in the vicinity thereof. It is connected to the lower part of the portion 25d (see FIGS. 11, 12, and 13).

According to this configuration, the cross member (inclined member 25) is extended directly or in the vicinity of the lower portion of the first vehicle body attachment portion (rear mount portion M4) by the above-described arm support portion (see the lower bracket 33) in the event of a collision. Since the collision load is transmitted to the lower portion of the portion 25d, the first vehicle body attachment portion (rear mount portion M4) can be twisted in the direction of pulling out from the vehicle body, and the separation can be promoted. When claim 5 is dependent on claim 4, the torsional moment is generated because the torsional load is transmitted to the lower portion of the rear portion 25c after the weakened portion of the extended portion 25d of the inclined member 25 is crushed. Effectively, it becomes easier to remove the rear mount part M4.
Further, the connecting portion (connecting portion Y) of the cross member (inclined member 25) to the arm support portion (the brackets 32, 33) is a portion on the center side in the vehicle width direction with respect to the connecting portion (connecting portion Y). It is made weaker by being made thinner (see FIG. 13).

According to this structure, it can achieve by making the weak structure of the connection part (connection part Y) with the arm support part (refer each bracket 32 and 33) of a cross member (inclination member 25) thin.
Further, the cross member (inclined member 25) is weakened by connecting the connecting portion (connecting portion Y) to the arm support portion (see the brackets 32 and 33) as a bent portion (see the bent portion 25e). (See FIG. 13).

  According to this configuration, the fragile structure of the connecting portion (connecting portion Y) of the cross member (inclined member 25) with the arm support portion (respective brackets 32 and 33) is a bent portion (bending portion 25e). can do.

  15 to 23 show other embodiments of the sub-frame structure of an automobile, FIG. 15 is a side view thereof, FIG. 16 is a bottom view of FIG. 15, FIG. 17 is a perspective view showing the sub-frame structure, and FIG. 19 is an exploded perspective view, FIG. 19 is a partially enlarged perspective view of FIG. 17, FIG. 20 is a perspective view showing the peripheral structure of the tower portion as the vehicle body mounting portion shown in FIG. 22 is a cross-sectional view on the right side of the vehicle along the line DD, FIG. 22 is a cross-sectional view on the right side of the vehicle along the line EE in FIG. 17, and FIG. 23 is an arrow on the right side of the vehicle along the line GG in FIG. FIG.

  15 to 23, the front side member 21F and the rear side member 21R are integrally connected in the front-rear direction. Each of these side members 21F and 21R can be integrally formed by forming a metal pipe into a square frame shape on the front side and a round pipe shape on the rear side by hydroforming the metal pipe.

As shown in a sectional view in FIG. 23, also in this embodiment, the tower portion 22 includes a mount bracket upper 22a and a mount bracket lower 22b, and the tower portion 22 extends from the lower surface of the side members 21F and 21R to the vehicle width. As shown in FIGS. 23 and 20, front and rear lower arm support portions 22d and 22e are provided at the lower portion of the closed cross section 22c, and the lower end of the lower cross section 22c extends outward and upward in the direction. The lower surface portion 22f is connected to the lower surface of the side member 21R by welding.
Further, as shown in a perspective view of FIG. 19, upper surface portions 22g of the lower left and right tower portions 22 (only the right tower portion 22 is shown in the drawing) are connected to the upper surfaces of the side members 21F and 21R by welding. Has been.

  As shown in FIGS. 20 and 23, the front and rear lower arm support portions 22d and 22e of the tower portion 22 are formed on the outer surface in the vehicle width direction, and the outer surface in the vehicle width direction, that is, the mount bracket lower 22b is shown in FIG. As shown, it is formed between the side members 21F, 21R and the front side frame 7 so as to be inclined substantially linearly.

  As shown in FIG. 20, also in this embodiment, the lower arm support portions 22d and 22e before and after the tower portion 22 have their closed cross sections 22c branched substantially back and forth so that the front support portion 22d and the rear support portion 22e Is formed.

As shown in the bottom view in FIG. 16, the center cross member 24 is displaced rearward from the tower portion 22 so that the rear support portion 22e of the tower portion 22 and the vehicle front-rear position overlap each other in the entire length in the vehicle width direction. Is arranged.
Also, as shown in FIG. 16, the center cross member 24 is extended by inclining the left and right ends of the center cross member 24 toward the mount portion side of the tower portion 22 in the longitudinal direction of the vehicle, more specifically toward the front lower arm support portion 22d side. An extension portion 24f extending obliquely outward and forward is formed, and this extension portion 24f is connected to the side members 21F and 21R as shown in FIGS. A rear bulge portion 24e that protrudes rearward from the rear edge of the left and right side portions is integrally formed at the opposite side of the vehicle longitudinal direction relative to the side where the extension portion 24f is formed in the member 24, that is, at the center portion in the vehicle width direction on the rear side. As shown in FIGS. 16 and 17, an inclined member 25 is connected to the rear bulge portion 24e.

The above-described center cross member 24 is closed by a center cross member upper 24a and a center cross member lower 24b, and the extension 24f is connected to the side members 21F and 21R to concentrate stress in the vehicle width direction load. It is configured to relax.
Further, as shown in FIGS. 16, 20, and 23, the above-mentioned side member 21R at the position where the center cross member 24 and the tower portion 22 overlap in the vehicle longitudinal direction passes through the side member 21R in the vertical direction. A stabilizer mounting bush 44 is provided as an accessory mounting bush for connecting the upper and lower surfaces of the side member 21R by welding.
A stabilizer (not shown) as an auxiliary machine is attached to both the bush 44 and the bush 45 immediately after the bush via stabilizer support brackets 36 and 37.

Of the pair of front and rear stabilizer mounting bushes 44, 45, the front bushing 44 is provided at a position overlapping both the center cross member 24 and the tower portion 22, as shown in FIG. The front and rear bushes 44, 45 penetrate the side member 21R vertically and are connected to the upper and lower surfaces by welding.
Further, the front bush 44 overlaps with the rear lower arm support portion 22e in the tower portion 22. With this configuration, the side members 21F and 21R, particularly when the load is input while the stabilizer is mounted in the vehicle width direction. The rear side member 21R is configured to prevent the closed cross section from being crushed.

Further, as shown in FIG. 20, the side member in the vehicle width direction outer end portion of the center cross member lower 24b constituting the center cross member 24 having the closed cross-section structure is in the vicinity of the bushes 44 and 45 and is not affected by the heat of welding. The tower portion 22 is connected to the center cross member 24 via the bush reinforcement portions of the side members 21F and 21R.
20 and 22, reference numeral 21a denotes a recess formed in the side member 21R for the purpose of avoiding interference with the lower arm 40.

  Also in the sub-frame structure of the automobile of the second embodiment shown in FIGS. 15 to 23, the sub-frame structure of the automobile is constructed below the pair of left and right front side frames 7 and 7 extended to the front side of the passenger compartment. The sub-frame 20 includes left and right side members 21F and 21R extending in the vehicle front-rear direction, and cross members (inclined members) connected to the vehicle side end portions of the left and right side members 21F and 21R and extending in the vehicle width direction. 25), an extending portion 25d extending outward in the vehicle width direction from the side member connecting portion X of the cross member (see the inclined member 25), and an outer end portion of the extending portion 25d of the cross member (inclining member 25). A first vehicle body mounting portion (see rear mount portion M4) mounted on the vehicle body, an extended portion 25d of the cross member (inclined member 25), and the side member 1R, and an arm support portion (see the upper bracket 32 and the lower bracket 33) that supports the arm of the suspension (see the lower arm 40), and the arm support portions (the brackets 32 and 33) are The cross member (inclined member 25) is connected between the side member connecting portion X and the first vehicle body mounting portion (rear mount portion M4), and the cross member (inclined member 25) has an arm support portion ( The connecting portion with each bracket 32, 33) is made weaker in the vehicle front-rear direction than the portion on the center side in the vehicle width direction with respect to the connecting portion. (See FIGS. 16 and 17).

Therefore, also in the second embodiment, the central portion in the vehicle width direction of the cross member (inclined member 25) is highly rigid, and the cross member (inclined member 25) is connected to the arm support portion (see brackets 32 and 33). Although the connecting portion is fragile, since it is reinforced by the arm support portions (respective brackets 32 and 33), the connecting rigidity of the left and right side members 21F and 21R and the first vehicle body mounting portion (rear mount) are normally used. The peripheral rigidity can be ensured.
In addition, at the time of a collision in the front-rear direction of the automobile, the side member 21R and the arm support (see brackets 32 and 33) are connected to the above-described cross member (inclined member 25) at the connection portion with the arm support (see brackets 32 and 33). Even if the first vehicle body mounting portion (rear mount portion M4) does not come off due to the transmission load (stress concentration) from the rear, the extending portion 25d of the cross member (inclined member 25) is crushed in the front-rear direction, thereby The side member 21R can be easily moved (retracted) toward the passenger compartment, and the collision load peak can be reduced.
In addition, in this Example 2 shown in FIGS. 15-23, since another structure, an effect | action, and an effect are the same as that of previous Example 1, in FIG. 15-23, it is the same as the previous figure. Parts are denoted by the same reference numerals and detailed description thereof is omitted, but in the drawing, an arrow UP indicates the upper side of the vehicle.

FIG. 24 is a bottom view showing still another embodiment of the sub-frame structure of the automobile.
In the first and second embodiments, the inclined member 25 is substantially V-shaped in plan view and has a left and right non-divided structure. In the third embodiment shown in FIG. Members 25A and 25B are employed.

Each of these inclined members 25A and 25B is a member made of a metal pipe having an inclined portion 25b and an extending portion 25d including a rear portion 25c and a bent portion 25e, and the front ends of the inclined members 25A and 25B are centered. The cross member 24 is connected to the inclined vertical wall portion of the rear bulge portion 24e, and the rear portion 25c is connected to the rear lower surface of the front side frame 7 at the rear mount portion M4 (so-called No. 4 mount portion). ing.
Thus, even if the inclined members 25A and 25B are divided into left and right structures, the same operations and effects as in the previous embodiments 1 and 2 can be obtained. Therefore, in FIG. The same reference numerals are assigned and detailed description thereof is omitted.

FIG. 25 shows still another embodiment of the sub-frame structure of the automobile, FIG. 25 (a) is a plan view of the main part showing another embodiment of the fragile structure, and FIG. 25 (b) is a further view of the fragile structure. It is a top view of the principal part which shows another Example.
The structure shown in FIG. 25A is such that the connecting portion Y of the inclined member 25 to the arm support portion (upper bracket 32, lower bracket 33) is located with respect to the connecting portion Y from the central portion in the vehicle width direction. As a structure that becomes weak in the longitudinal direction of the vehicle, it is configured by at least one opening 61 instead of the structure by the tailored blank described above.

In the structure shown in FIG. 25A, a plurality of the above-described openings 61 are formed in the extending portion 25d excluding the rear portion 25c of the inclined member 25 and the side member connecting portion X.
Even if comprised in this way, the predetermined part of the extension part 25d weakened by the some opening part 61 at the time of the input of the front collision load can be deform | transformed, and retreat | retreat of the side member 21R can be permitted.
In the structure shown in FIG. 25A, the degree of vulnerability can be easily adjusted by the diameter of the opening 61 and the number of openings 61.
Even if it is configured as shown in FIG. 25A, the other configurations, functions, and effects are almost the same as those in the previous embodiment. Therefore, in FIG. Are denoted by the same reference numerals, and detailed description thereof is omitted.

In the structure shown in FIG. 25 (b), the connecting portion Y of the inclined member 25 with the arm support portion (upper bracket 32, lower bracket 33) is located with respect to the connecting portion Y from the central portion in the vehicle width direction. As a structure that becomes brittle in the vehicle front-rear direction, a long hole 62 is used instead of the structure using the tailored blank described above.
In the structure shown in FIG. 25B, the above-described long hole 62 is formed in the extending portion 25d excluding the rear portion 25c and the side member connecting portion X in the inclined member 25 so as to substantially follow the shape of the bent portion 25e. doing.
Even if comprised in this way, the predetermined part of the extension part 25d weakened by the long hole 62 at the time of the input of the front collision load can be deformed, and the retreat of the side member 21R can be permitted.

In the structure shown in FIG. 25B, the degree of vulnerability can be easily adjusted by the opening width (width in the front-rear direction) and the opening length (that is, opening area) of the long hole 62.
Even if configured as shown in FIG. 25 (b), the other configurations, functions, and effects are almost the same as those of the previous embodiment. Therefore, in FIG. Are denoted by the same reference numerals, and detailed description thereof is omitted.

In the correspondence between the configuration of the present invention and the above-described embodiment,
The side frame of the present invention corresponds to the front side frame 7 of the embodiment,
Similarly,
The cross member corresponds to the inclined members 25, 25A, 25B,
The side member connecting portion of the cross member corresponds to the side member connecting portion X of the inclined member 25,
The first vehicle body attachment portion corresponds to the rear mount portion M4,
The suspension arm corresponds to the lower arm 40,
The arm support portion corresponds to the upper bracket 32 and the lower bracket 33,
The connection part with the arm support part of the cross member corresponds to the connection part Y,
The second vehicle body mounting portion corresponds to the inside mount portion M3,
The third vehicle body attachment portion corresponds to the center mount portion M2,
One bracket corresponds to the upper bracket 32,
The connecting portion of one bracket to the extending portion of the cross member is a connecting portion to the extending portion 25d of the inclined member 25 of the upper bracket 32 (the upper connecting portion of the upper and lower connecting portions Y, Y shown in FIG. 11). Part Y),
The other bracket corresponds to the lower bracket 33,
The bent portion corresponds to the bent portion 25e,
The present invention is not limited to the configuration of the above-described embodiment.

For example, in the above embodiment, the case where the sub-frame structure of an automobile is applied to the front side has been described, but the present invention can also be applied to the sub-frame structure on the rear side.
Further, as the arm support portion, the upper bracket 32 and the lower bracket 33 which are separate from the side member 21R and the inclined member 25 are illustrated, but the arm support portion may be integrally formed with the side member 21R. .
Further, the weak structure at the connecting portion of the inclined member with the arm support portion is formed by slitting a predetermined portion of the extending portion 25d of the inclined member 25 in place of the thinned structure by the tailored blank and the structure by the opening 61 or the long hole 62. The structure may form a fragile structure by combining these.

  As described above, the present invention is useful for a pair of left and right front side frames extending on the front side or the rear side of a passenger compartment, or a subframe structure of an automobile built under a rear side frame.

7. Front side frame (side frame)
20 ... Subframes 21F, 21R ... Side members 25, 25A, 25B ... Inclined members (cross members)
25d ... Extension part 25e ... Bending part (bending part)
32 ... Upper bracket (arm support)
33 ... Lower bracket (arm support)
40 ... Lower arm (Suspension arm)
M2 ... Center mount part (third body mounting part)
M3 ... Inside mount part (second body mounting part)
M4 ... Rear mount part (first body mounting part)
X ... side member connecting part Y ... connecting part (connecting part)

Claims (6)

A sub-frame structure of an automobile constructed under a pair of left and right side frames extending on the front side or the rear side of a passenger compartment,
The subframe includes left and right side members extending in the vehicle front-rear direction,
A cross member connected to the vehicle compartment side end of the left and right side members and extending in the vehicle width direction;
An extending portion extending outward in the vehicle width direction from the side member connecting portion of the cross member;
A first vehicle body mounting portion provided at an outer end portion of the extending portion of the cross member and mounted to the vehicle body;
An extended portion of the cross member and an arm support portion that is connected to the side member and supports the arm of the suspension;
The arm support portion is connected between the side member connecting portion of the cross member and the first vehicle body mounting portion,
The connection part of the cross member with the arm support portion is made weaker in the vehicle front-rear direction than the central part of the vehicle width direction with respect to the connection part ,
The arm support part consists of an upper bracket and a lower bracket,
A connecting portion between at least one bracket and the extending portion of the cross member is separated from the first vehicle body mounting portion;
The sub-frame structure of an automobile, wherein the other bracket is connected to the first vehicle body attachment portion directly or to an extension portion in the vicinity thereof . The sub-frame structure for an automobile according to claim 1, wherein a second vehicle body attachment portion that can be detached by receiving a load in the front-rear direction is connected in the vicinity of the side member connection portion of the cross member. The sub-frame structure for an automobile according to claim 1 or 2, wherein a third vehicle body mounting portion that can be detached by a longitudinal displacement is provided at an outer portion in the longitudinal direction of the side member. The automobile according to any one of claims 1 to 3, wherein the arm support portion is directly connected to a lower portion of the first vehicle body mounting portion or connected to a lower portion of the extending portion of the cross member in the vicinity thereof. Subframe structure. The connection part with the arm support part of the said cross member is weakened by making it thinner than the site | part of the vehicle width direction center side with respect to this connection part, The any one of Claims 1-4 Automobile subframe structure. Connecting portion between the arm support portion of the cross member, automobile subframe structure according to any one of claims 1 to 5, in which the weakened that are bent site.

Images