JP2003205853A - Subframe for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a subframe for an automobile capable of ensuring a large approach angle of the vehicle. <P>SOLUTION: In the subframe 1 attached to a lower part of a vehicle body frame 2 having a pair of right and left front side members 3 and a radiator front lower 4 connected with a front end side of each front side member 3, right and left extended parts 6 arranged on a lower side of the radiator front lower 4 are platelike bodies 12 along a lower face of the radiator front lower 4, and a ground clearance in a vehicle front part is large. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile subframe mounted on a lower portion of a vehicle body frame.

[0002]

2. Description of the Related Art As a vehicle body frame of an automobile, a pair of left and right front side members extending substantially in the front-rear direction and a cross member (radiator front lower) having both ends connected to the front ends of the front side members and extending in the substantially left-right direction are provided. The ones are common. And at the bottom of this body frame, support for suspension links on the front side,
BACKGROUND ART An automobile vehicle to which a subframe is attached is known in order to improve body rigidity.

This kind of sub-frame is generally formed in a substantially U-shape along the lower surface of each front side member and radiator front lower. That is, the subframe includes a pair of left and right subframe main body portions that are connected to the lower surface side of each front side member and extend in the front-rear direction, and a front end extending in the left-right direction from the front end side of each subframe main body portion along the lower surface of the cross member. And a connecting portion. The front end connecting portion has a substantially quadrangular shape in a side section by joining an upper member formed in a substantially hat shape and a lower member formed in a substantially inverted hat shape.

[0004]

By the way, in the sub-frame, the front end connecting portion is formed in a substantially square shape, and the vertical dimension of the front end connecting portion is relatively large. That is, in a vehicle equipped with the sub-frame, the front end connecting portion of the sub-frame is located on the lower surface of the radiator front lower, and the distance between the vehicle and the ground on the vehicle front end side becomes small, so that the approach angle (proximity angle) of the vehicle is reduced. ) Is relatively small. Therefore, a relatively large approach angle is required in order to avoid interference with the road surface R
In the case of a V car or the like, the structure using the subframe has a problem that a sufficient approach angle cannot be secured.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a subframe of an automobile capable of ensuring a large approach angle of the vehicle.

[0006]

In order to achieve the above object, in the invention according to claim 1, a pair of left and right front side members extending substantially in the front-rear direction and both end sides are connected to the front end side of each front side member and substantially left and right sides. A cross member extending to the lower side of the vehicle body frame, the pair of left and right sub frame main body portions that are connected to the lower surface side of each of the front side members and extend substantially in the front-and-back direction; A left and right extending portion extending from the front end side to the center of the left and right side of the cross member, the left and right extending portion being formed along the lower surface of the cross member. It is characterized in that it is a plate-shaped body.

According to the first aspect of the invention, the left and right extending portions formed along the lower surface of the cross member are located below the cross member of the vehicle body frame. Here, since the left and right extending portions are one plate-shaped body, the vertical dimension is relatively small, and the distance between the vehicle and the ground at the vehicle front end portion is relatively large.

Therefore, the ground clearance at the front end of the vehicle is increased, and a large approach angle of the vehicle can be secured. In particular, in order to avoid interference with the road surface, it is extremely advantageous in RV vehicles and the like that require a large approach angle for the vehicle, and the degree of freedom in design and the like is dramatically improved.

According to a second aspect of the present invention, in the subframe of the automobile according to the first aspect, the left and right extending portions are respectively connected to the front end sides of the respective subframe main body portions and are provided on the lower surface of both ends of the cross member. A left frame and a right frame, each of which has a pair of left and right end plate-like members, respectively, and each of which has the sub-frame main body and the end plate-like members connected to the sub-frame main body; Is characterized by.

According to the second aspect of the present invention, in addition to the function of the first aspect, the end plate members of the left and right extending portions are respectively located on the lower surfaces on both end sides of the cross member, and the lower surface on the central side of the cross member. There is no component part of the left-right extending part in. Further, when the sub frame is assembled to the body frame, the left frame and the right frame are separately assembled to the body frame. At this time, since the left and right frames are configured independently of each other, unlike the conventional one in which the left and right subframe body parts are connected, a high dimension between the subframe body parts is required when assembled to the vehicle body frame. Accuracy is not required, and dimensional errors and the like are relatively tolerable.

Therefore, there is no member located on the lower surface on the center side of the cross member provided in the conventional subframe, the weight and size of the subframe can be reduced, and the manufacturing cost of the vehicle is reduced. can do. Further, since the weight of the vehicle can be reduced, not only the fuel consumption of the vehicle can be improved, but also in the front engine vehicle, the weight of the front portion of the vehicle where the prime mover is mounted and the weight is heavy is reduced. Therefore, it is possible to dramatically improve the running performance such as the motion performance of the vehicle. In addition to assembling the left frame and the right frame separately, the dimensional error of each of the left and right frames is relatively allowed, so that the subframe can be easily assembled to the vehicle body frame. Further, since the left and right frames are independently configured, it is extremely advantageous when the subframe is transported in a vehicle manufacturing factory or the like.

In the invention according to claim 3, the invention according to claim 2
In the subframe of the automobile described above, the left frame and the right frame are fixed to the cross member on the front side and the rear side of the left and right center end sides of the end plate body, and The front end member is fixed to the front side member.

According to the third aspect of the present invention, in addition to the function of the second aspect, the front sides of the left frame and the right frame are located at the front and rear two positions of the cross member and at the front side of the front side member and are located on the vehicle body frame side. Fixed. That is, since the end plate members of the left frame and the right frame are fixed to the front and rear two positions of the cross member, the left frame and the right frame are connected via the cross member. This allows
When a rearward load is applied to one of the left frame and the right frame during an offset collision, the load is reliably transmitted to the other frame and the front side member via the cross member. Further, since the front parts of the left frame and the right frame are fixed to the front side of the front side member, the sub frame and each front side member are integrally deformed at the time of a frontal collision, so that the sub frame and the body frame are separated. The load acting rearward is dispersed.

Therefore, at the time of offset collision of the vehicle, the load is surely transmitted from one of the left frame and the right frame located on the collision side to the other frame and the front side member located on the non-collision side. Therefore, a predetermined offset collision performance can be secured, which is extremely advantageous in practical use. Further, in the case of a frontal collision of the vehicle, the load acting rearward is distributed to the subframe and the vehicle body frame, so that the rearward load can be efficiently received by the subframe and the vehicle body frame as a whole. Collision performance can be improved.

According to the invention of claim 4, the invention according to claim 1
The subframe of the automobile according to any one of claims 1 to 3, characterized in that a ridge extending in a direction substantially orthogonal to the front-rear direction is formed on the front end side of each main body.

According to the invention described in claim 4, in addition to the operation of any one of claims 1 to 3, when a front-back compression force is applied to the vehicle due to a frontal collision of the vehicle or the like, each of the main bodies is The front end sides of the parts are easily deformed in the compression direction starting from the ridges.

Therefore, in the case of a frontal collision of the vehicle, the energy of the collision can be reliably absorbed at the front end side of each sub-frame body.

[0018]

1 to 7 show an embodiment of the present invention. FIG. 1 is an exploded perspective view of a vehicle body frame and a subframe showing a front structure of an automobile, and FIG. It is an external appearance perspective view of a left frame.

As shown in FIG. 1, the subframe 1 for an automobile is attached to a lower portion of a vehicle body frame 2 at the front of the automobile. Here, the vehicle body frame 2 has a conventionally known configuration, and a pair of left and right front side members 3 extending substantially in the front-rear direction, and a radiator as a cross member having both ends connected to the front end sides of the front side members 3 extending substantially in the left-right direction. It has a lower frame 4.

As shown in FIG. 2, this subframe 1
Is a pair of left and right sub-frame body portions 5 connected to the lower surface side of each front side member 3 and extending in the front-rear direction, and the radiator lower frame 4 from the front end side of each sub-frame body portion 5.
And a left-right extending portion 6 extending in the left-right direction along the lower surface of the. In this embodiment, each sub-frame body 5 has a sub-frame front body 7 that forms a front portion thereof and a sub-frame rear 8 that forms a rear portion thereof. 8 is fixed by welding or the like.

As shown in FIGS. 3 to 5, each of the sub-frame front side main body portions 7 is formed in a substantially hat shape in a front cross section and extends in the front and rear direction, and a sub frame front upper 9 is formed in a substantially inverted hat shape in a front cross section. The sub-frame front lower 10 is formed and extends in the front-rear direction. These members form a substantially quadrangular closed cross section in a front cross section. The sub-frame front upper 9 and the sub-frame front lower 10 are formed by pressing metal such as iron or aluminum. In the present embodiment, flanges 9a and 10a that extend laterally outward and are welded to each other by spot welding or the like are provided at the left and right ends of the subframe front upper 9 and the subframe front lower 10, and extend forward to the front end and are spot welded to each other. Flanges 9b and 10 welded by
b are formed respectively. Further, in the present embodiment, as shown in FIG. 7, the subframe front lower 1
0 has a substantially inverted hat shape in which the central portion is slightly recessed, and the subframe front upper 9 has a substantially hat shape in which the central portion is recessed more than the subframe front lower 10. In this embodiment, the front end side of the sub-frame front lower 10 is continuously formed with a portion extending toward the center in the left-right direction, and this portion forms the left-right extending portion 6 described above.

Further, as shown in FIGS. 3 and 4, a plurality of beads 11 extending in a direction orthogonal to the front-rear direction are formed on each front main body portion 7 of each sub-frame. That is, each bead 11 as a ridge portion is formed on the upper surface and each side surface of the subframe front upper 9 and the subframe front lower 10.
Are continuously formed on the respective side surfaces and the upper surface, and extend substantially vertically on the respective side surfaces and extend substantially laterally on the upper surface and the lower surface. In this embodiment, a total of five beads 11 are formed side by side in the front-rear direction, and each of the front beads 11 is formed.
The front-rear spacing of each bead 11 on the rear side is relatively large.

Here, a fixing hole 9c is formed on the upper surface of the sub-frame front upper 9, and the sub-frame front upper 9 is fixed to the front side member 3 by a bolt (not shown) inserted through the fixing hole 9c. That is, the subframe 1 is fixed to the front side member 3 side on the front side of each subframe body 5.

Each sub-frame rear 8 is connected to the rear end side of each sub-frame front side main body portion 7 and is formed in a substantially square shape in a front cross section. In the present embodiment, each sub-frame rear 8 is formed by hydroforming a metal such as iron or aluminum, and is formed into a substantially rectangular tube shape extending in the front-rear direction. Each sub-frame rear 8 is also fixed to each front side member 3 side similarly to the sub-frame front upper 9.

The left and right extending portions 6 are formed continuously with the front end side of the left subframe main body 5 and are located at the left end side lower surface of the radiator frame lower 4 on the left end side lower plate 12, and the right subframe main body part. 5 and a right end side plate-like body 13 formed continuously with the front end side of the radiator frame lower member 4 and located on the lower surface of the radiator frame lower 4 on the right end side. In the present embodiment, the left end side plate-like body 12 and the right end side plate-like body 13 are provided corresponding to a predetermined section of the radiator frame lower 4 toward the left and right center sides. That is, the subframe 1 according to the present embodiment includes the left subframe body 5 and the left end side plate-like body 12.
A left frame 1a having a substantially L shape and a right frame 1b having a right sub-frame body 5 and a right end side plate 13 and having a substantially L shape, The left frame 1a and the right frame 1b are independent of each other.

The left end side plate-like body 12 and the right end side plate-like body 13 of each sub-frame front lower 10 are formed in a substantially inverted hat shape in a side cross section along the lower surface of the radiator front lower 4.

Here, the radiator front lower 4 will be described in detail. As shown in FIG. 6, the radiator front lower 4 is spot welded to an upper member 4a formed in a substantially hat shape in a side cross section and a lower member 4b formed in a substantially inverted hat shape in a side cross section. It is formed by welding. In the present embodiment, the lower wall portion 4b1 of the lower member 4b is substantially horizontal, and the vertical wall portion 4b on the front side is formed.
2 is formed longer in the up-down direction than the vertical wall portion 4b3 on the rear side. The vertical wall portion 4b2 on the front side is inclined forward and upward, and the vertical wall portion 4b3 on the rear side is inclined upward and upward. Then, from the upper ends of the vertical wall portions 4b2, 4b3, flanges 4b4, 4b5 extending outward in the front-rear direction are formed, respectively, and the flanges 4b4, 4b5 are respectively formed with the flanges 4a1, 4a1 of the upper member 4a.
4a2 is welded by spot welding or the like.

As shown in FIG. 6, the plate member 12 on the left end side is
Similar to the lower member 4b of the radiator front lower 4, the lower wall portion 12a, the front vertical wall portion 12b, the rear vertical wall portion 12c, and the front and rear outer sides from the upper ends of the vertical wall portions 12b, 12c. It has extending flanges 12d and 12e.
Each wall 12a, 12b, 12c is along the lower surface of the lower member 4b, and each wall 4b1, 4b2, 4b3 of the lower member 4b.
Slightly separated from. Each flange 12d, 12e
Are substantially in contact with the flanges 4b4, 4b5 of the lower member 4b and are fixed to the radiator front lower 4 at the right end side thereof. In the present embodiment, the left end side plate-shaped body 1
Fixing holes 12f formed at the left and right center ends (right end sides) of the flanges 12d and 12e, respectively, and the upper member 4
The front side of the left frame 1a is fixed to the radiator front lower 4 by using a bolt 13 that inserts the flanges 4a1 and 4a2 of a and the flanges 4b4 and 4b5 of the lower member 4b. The left end side plate-shaped body 12 and the right end side plate-shaped body 13 are formed symmetrically, and the right end side plate-shaped body 13 has the same configuration as the left end side plate-shaped body 12, and therefore the description thereof is omitted here.

In the sub-frame 1 constructed as described above, the radiator front lower 4 of the vehicle body frame 2 is
The left and right extending portions 6 along the lower surface are located on the lower surface. Here, the left and right extending portions 6 are formed into a single plate-shaped body,
Since the vertical dimension is relatively small, the distance from the ground at the front of the vehicle is relatively large. That is, the left-right extending portion 6 of the present embodiment has a remarkably smaller vertical dimension than, for example, a conventionally known one having a hollow closed cross section, and the distance from the ground at the vehicle front portion compared to the conventionally known one. Will be significantly larger.

Further, the sub-frame 1 to the body frame 2
When assembled, the left frame 1 is formed in a substantially L shape.
a and the right frame 1b are separately assembled to the front side members 3 and the radiator front lower 4. At this time, since the left and right frames 1a and 1b are configured separately from each other, dimensional errors and the like of the subframe 1 and the like are relatively allowed. That is, unlike the conventional one in which the left and right subframe main body portions are connected to each other and are formed in a substantially U-shape, high dimensional accuracy between the subframe main body portions is not required at the time of assembly to the vehicle body frame.

Further, the left frame 1a and the right frame 1b
The left and right extending portions 6 of the radiator front lower 4
Since it is fixed to the location, the left frame 1a and the right frame 1b are connected via the radiator front lower 4. As a result, when an offset collision occurs, the left frame 1a
When a rearward load is applied to one of the right frame 1b and the right frame 1b, the load is reliably transmitted to the other frame 1a, 1b and the front side member 3 via the radiator front lower 4. In the present embodiment, the sub-frame main body 5 is configured to be located at substantially the same height as the radiator front lower 4, and the bending moment generated between these members at the time of offset collision is reduced, and the other The load is smoothly transmitted to the frames 1a and 1b and the front side member 3. further,
Since the front portions of the left frame 1a and the right frame 1b are fixed to the front end side of the front side member 3, the sub frame 1 and each front side member 3 are integrally deformed during a frontal collision, and the sub frame 1 And body frame 2
The load acting backward is distributed to and.

Further, when a compressive force in the front-rear direction is applied to the vehicle due to a frontal collision of the vehicle or the like, the front end side of each sub-frame body portion 5 is easily deformed in the compression direction starting from the bead 11.

As described above, the subframe 1 of this embodiment
According to this, the distance from the ground in the front part of the vehicle is set to be relatively large, so that a large approach angle of the vehicle can be secured. In particular, in order to avoid interference with the road surface, it is extremely advantageous in RV vehicles and the like that require a large approach angle for the vehicle, and the degree of freedom in design and the like is dramatically improved.

Further, according to the sub-frame 1 of the present embodiment, there is no member located on the lower surface on the central side of the radiator front lower 4, so that the weight and size of the sub-frame 1 can be reduced, and the vehicle can be made smaller. It is possible to reduce the manufacturing cost. Further, it is of course possible to improve the fuel efficiency of the vehicle along with the weight reduction of the vehicle, and in a front engine vehicle, it is possible to reduce the weight of the front portion of the vehicle where the prime mover is mounted and the weight is heavy. It is possible to dramatically improve running performance such as vehicle motion performance.

Further, according to the sub-frame 1 of this embodiment, the left frame 1a and the right frame 1b are separately assembled, and in addition, dimensional errors and the like of the left and right frames 1a and 1b are relatively allowed. The subframe 1 can be easily attached to the vehicle body frame 2. Further, since the left and right frames 1a and 1b are independently configured, it is extremely advantageous when the sub-frame 1 is transported in a vehicle manufacturing factory or the like.

Further, according to the sub-frame 1 of this embodiment, one of the left frame 1a and the right frame 1b located on the collision side to the other frame and the front side located on the non-collision side at the time of an offset collision of the vehicle. Since the load is reliably transmitted to the member 3, it is possible to secure a predetermined offset collision performance while increasing the approach angle of the vehicle and reducing the weight of the subframe 1 as described above. It is extremely advantageous for practical use.

Further, according to the sub-frame 1 of this embodiment, the load acting rearward is distributed to the sub-frame 1 and the vehicle body frame 2 at the time of a frontal collision of the vehicle. And front side member 3
The force in the compression direction is dispersed in the and, the rearward load can be efficiently received by the subframe 1 and the entire body frame 2, and the collision performance of the vehicle can be improved.

Further, according to the sub-frame 1 of the present embodiment, when a compressive force in the front-rear direction is applied to the vehicle due to a frontal collision of the vehicle or the like, each sub-frame main body 5 is easily started from the bead 11 as a starting point. Since it is deformed in the compression direction, the energy of collision or the like can be reliably absorbed on the front end side of each sub-frame main body portion 5 in the case of a frontal collision or the like of the vehicle.

Although the sub-frame 1 is divided into the left frame 1a and the right frame 1b in the above embodiment, the plate-like body 6 is arranged on the lower surface of the radiator front lower 4. It goes without saying that a large approach angle of the vehicle can be ensured regardless of the configuration of the vehicle.

The shape and number of the beads 11 and the fixing structure of the sub-frame 1 to the vehicle body frame 2 in the above-described embodiment are arbitrary within the scope of achieving the object of the present invention, and other specific Needless to say, the detailed structure and the like can be changed as appropriate.

[0041]

As described above in detail, according to the sub-frame of the present invention, the distance from the ground at the front of the vehicle is made relatively large, so that a large approach angle of the vehicle can be secured. .

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is an exploded perspective view of a vehicle body frame and a subframe showing a front structure of an automobile.

FIG. 2 is an external perspective view of a left frame of the sub-frame.

FIG. 3 is a side view showing a front main body of a subframe of the left frame.

FIG. 4 is a top view showing the front part of the left frame.

FIG. 5 is a side cross-sectional view showing a subframe front side main body portion of the left frame.

FIG. 6 is a side sectional view showing a radiator front lower and a left end side plate member of the left sub-frame.

FIG. 7 is a front sectional view of a front portion of the left sub-frame.

[Explanation of symbols]

1 subframe 1a left frame 1b right frame 2 body frame 3 Front side members 4 radiator front lower 5 Subframe body 6 left and right extension 11 beads 12 Left end side plate 13 Plate on right side

Claims (4)

[Claims] 1. A subframe attached to a lower portion of a vehicle body frame having a pair of left and right front side members extending substantially in the front-rear direction, and a cross member having both ends connected to front ends of the front side members and extending substantially in the left-right direction. A pair of left and right sub-frame main body portions that are connected to the lower surface side of each of the front side members and extend substantially in the front-rear direction; A left-right extending portion, and the left-right extending portion is a single plate-like body formed along the lower surface of the cross member. 2. The left and right extending portions have a pair of left and right end plate-like members respectively connected to the front end sides of the respective sub-frame main body portions and respectively located on the lower end side lower surfaces of the cross member, 2. The subframe for an automobile according to claim 1, wherein the subframe comprises a left frame and a right frame which are independent of each other and each have a frame main body and the end plate member connected to the frame main body. 3. The left frame and the right frame are fixed to the cross member on the front side and the rear side of the left and right center ends of the end plate-like body, and on the front end side of the sub-frame main body. The subframe of the automobile according to claim 2, wherein the subframe is fixed to the front side member. 4. The automobile according to claim 1, wherein a ridge portion extending in a direction substantially orthogonal to the front-rear direction is formed on the front end side of each of the sub-frame main body portions. Subframe.