JP4018909B2 - Car subframe - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automobile sub-frame attached to a lower part of a body frame.
[0002]
[Prior art]
2. Description of the Related Art A vehicle body frame generally includes a pair of left and right front side members extending substantially front and rear, and a cross member (radiator front lower) that is connected to both front ends of the front side members and extends substantially left and right. It is. An automobile vehicle is known in which a sub-frame is attached to the lower part of the vehicle body frame in order to support suspension links on the front side, improve vehicle body rigidity, and the like.
[0003]
This type 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 is connected to the lower surface side of each front side member and extends in the front-rear direction, and the front end extending in the left-right direction along the lower surface of the cross member from the front end side of each subframe main body portion. And a connecting portion. The front end connecting portion has a substantially rectangular shape in a side cross-section by joining an upper member formed in a substantially hat shape and a lower member formed in a substantially inverted hat shape.
[0004]
[Problems to be solved by the invention]
By the way, in the said sub-frame, the front end connection part is formed in the substantially square shape, and a vertical dimension becomes comparatively large in a front end connection part. That is, in a vehicle equipped with the subframe, the front end connecting portion of the subframe is located on the lower surface of the radiator front lower, and the distance between the vehicle and the ground on the front end side of the vehicle becomes small. ) Is relatively small. Accordingly, in an RV vehicle or the like that requires a relatively large approach angle in order to avoid interference with the road surface, there is a problem that a sufficient approach angle cannot be secured with the structure using the subframe. there were.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an automobile sub-frame capable of ensuring a large vehicle approach angle.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, there is provided a vehicle body having a pair of left and right front side members extending substantially front and rear, and a cross member extending from the front end side of each front side member to both front ends and extending substantially left and right. A subframe attached to a lower portion of the frame, a pair of left and right subframe main bodies connected to the lower surface side of each front side member and extending substantially front and rear, and from the front end side of each subframe main body section to the left and right center side And a left and right extending portion disposed on the lower side of the cross member, wherein the left and right extending portion is a single plate-like body formed along the lower surface of the cross member. And
[0007]
According to the first aspect of the present invention, the left and right extending portions formed along the lower surface of the cross member are located below the cross member of the body frame. Here, since the left and right extending portions are a single plate-like body, the vertical dimension is relatively small, and the distance between the vehicle and the ground at the vehicle front end is relatively large.
[0008]
Therefore, the ground clearance at the front end of the vehicle is increased, and a large approach angle of the vehicle can be ensured. In particular, in order to avoid interference with the road surface, it is extremely advantageous in an RV vehicle or the like in which a large approach angle is required for the vehicle, and the degree of freedom in design is drastically improved.
[0009]
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 subframe main body portions and are respectively located on the lower surfaces on both ends of the cross member. It has a pair of left and right end plate-like bodies, and is composed of an independent left frame and right frame each having the sub-frame main body portion and the end plate-like body connected thereto. To do.
[0010]
According to the second aspect of the present invention, in addition to the operation of the first aspect, the end plate-like bodies of the left and right extending portions are positioned on the lower surfaces on both ends of the cross member, respectively, The component part of the extension part is not located.
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, when assembling to the vehicle body frame, a high dimension between the subframe body portions is provided, as in the conventional case where the left and right subframe body portions are connected. Accuracy is not required, and dimensional errors are relatively acceptable.
[0011]
Accordingly, there is no member located on the lower surface of the center side of the cross member provided in the conventional subframe, and the subframe can be reduced in weight and size, and the manufacturing cost of the vehicle can be reduced. it can. Further, since the weight of the vehicle can be reduced, the fuel consumption of the vehicle can be improved. In addition, in the front engine vehicle, a prime mover or the like is mounted to reduce the weight of the front portion of the vehicle. 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, dimensional errors and the like of the left and right frames are relatively permissible, so that the subframe can be easily assembled to the vehicle body frame. In addition, since the left and right frames are configured independently, it is extremely advantageous when transporting the subframe in a vehicle manufacturing factory or the like.
[0012]
According to a third aspect of the present invention, in the automobile sub-frame according to the second aspect, the left frame and the right frame are crossed at the front side and the rear side of the left and right central ends of the end plate-like body. It is fixed to the member, and is fixed to the front side member on the front end side of the subframe main body.
[0013]
According to the invention of claim 3, in addition to the operation of claim 2, the front side of the left frame and the right frame is fixed to the vehicle body frame side at two front and rear positions of the cross member and one front side member of the front side member. .
That is, since the end plate-like bodies of the left frame and the right frame are fixed at the two front and rear portions of the cross member, the left frame and the right frame are connected via the cross member. Accordingly, when a backward load acts on one of the left frame and the right frame at the time of 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 portions of the left and right frames are fixed to the front side of the front side member, the sub frame and each front side member are deformed integrally at the time of a frontal collision, so that the sub frame and the body frame are separated. The load acting backward is distributed.
[0014]
Therefore, in the event of an offset collision of the vehicle, the load is reliably 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. The offset collision performance can be secured, which is extremely advantageous in practical use.
In addition, since the load acting on the rear is distributed to the subframe and the body frame at the time of the frontal collision of the vehicle, the load on the rear can be efficiently received by the entire subframe and the body frame. The collision performance can be improved.
[0015]
According to a fourth aspect of the present invention, in the automobile subframe according to any one of the first to third aspects, a protrusion extending in a direction substantially perpendicular to the front-rear direction is provided on the front end side of each main body. It is formed.
[0016]
According to a fourth aspect of the present invention, in addition to the operation of any one of the first to third aspects, when the vehicle is subjected to a longitudinal compression force due to a frontal collision of the vehicle, the front end of each main body portion Each side easily deforms in the compression direction starting from the ridge.
[0017]
Therefore, in the event of a frontal collision of the vehicle, energy such as a collision can be reliably absorbed on the front end side of each subframe main body.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
1 to 7 show an embodiment of the present invention. FIG. 1 is an exploded perspective view of a vehicle body frame and a sub frame showing a front structure of an automobile. FIG. 2 is an external perspective view of a left frame of the sub frame. is there.
[0019]
As shown in FIG. 1, the subframe 1 for an automobile is attached to the lower part of a 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 that extend substantially front and rear, and a radiator as a cross member that has both ends connected to the front end side of each front side member 3 and extends substantially left and right. And a lower frame 4.
[0020]
As shown in FIG. 2, the subframe 1 includes a pair of left and right subframe main bodies 5 connected to the lower surface side of each front side member 3 and extending in the front-rear direction, and a radiator lower frame from the front end side of each subframe main body 5. 4 and a left-right extending portion 6 extending in the left-right direction along the lower surface. In the present embodiment, each sub-frame main body 5 has a sub-frame front main body 7 that forms the front and a sub-frame rear 8 that forms the rear, and the sub-frame front main body 7 and the sub-frame rear 8 is fixed by welding or the like.
[0021]
As shown in FIG. 3 to FIG. 5, each sub-frame front main body portion 7 is formed in a substantially hat shape in the front cross section and extends in the front-rear direction, and is formed in a substantially reverse hat shape in the front cross section. A sub-frame front lower 10 and the like extending in the direction are formed, and these members form a substantially rectangular closed cross section in a front cross section. The subframe front upper 9 and the subframe front lower 10 are formed by pressing a metal such as iron or aluminum. In the present embodiment, flanges 9a and 10a extending to the left and right outer sides at the left and right ends of the subframe front upper 9 and the subframe front lower 10 are welded to each other by spot welding or the like. The flanges 9b and 10b to be welded are formed respectively. Further, in the present embodiment, as shown in FIG. 7, the subframe front lower 10 has a substantially inverted hat shape in which the central portion is slightly recessed, and the subframe front upper 9 is compared with the subframe front lower 10. Thus, the central portion is substantially hat-shaped with a large recess. In the present embodiment, a portion extending to the left and right center side is continuously formed on the front end side of the sub-frame front lower 10, and this portion constitutes the aforementioned left and right extending portion 6.
[0022]
Further, as shown in FIGS. 3 and 4, each subframe front body portion 7 is formed with a plurality of beads 11 extending in a direction orthogonal to the front and rear. That is, each bead 11 as a protrusion is formed continuously on the upper surface and each side surface of the subframe front upper 9 and each side surface and upper surface of the subframe front lower 10, and extends substantially vertically in each side surface. The upper and lower surfaces extend substantially in the left-right direction. In this embodiment, a total of five beads 11 are formed side by side, the front and rear intervals of the front beads 11 are relatively small, and the front and rear intervals of the rear beads 11 are relatively large.
[0023]
Here, a fixing hole 9 c 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) that passes through the fixing hole 9 c. That is, the subframe 1 is fixed to the front side member 3 side on the front side of each subframe main body 5.
[0024]
Each sub-frame rear 8 is connected to the rear end side of each sub-frame front body 7 and is formed in a substantially quadrangular shape in a front cross section. In this embodiment, each sub-frame rear 8 is formed by a hydroforming process of a metal such as iron or aluminum, and is formed in 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 in the same manner as the sub-frame front upper 9.
[0025]
The left and right extending portions 6 are formed continuously with the front end side of the left subframe main body portion 5 and are located on the left end side lower surface of the radiator frame lower 4 and the front end of the right subframe main body portion 5. And a right end side plate-like body 13 which is formed continuously with the side and located on the lower surface of the right end side of the radiator frame lower 4. 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 side. That is, the subframe 1 of the present embodiment includes a left frame 1a having a left subframe body 5 and a left end side plate-like body 12 and formed in a substantially L shape, a right subframe body 5 and a right end. The left frame 1a and the right frame 1b are independent of each other. The right frame 1b includes a side plate 13 and is formed in a substantially L shape.
[0026]
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.
[0027]
Here, the radiator front lower 4 will be described in detail. As shown in FIG. 6, the radiator front lower 4 is formed by spot welding or the like of an upper member 4 a formed in a substantially hat shape in a side section and a lower member 4 b formed in a substantially inverted hat shape in a side section. It is formed by welding. In the present embodiment, the lower wall 4b1 of the lower member 4b is substantially horizontal, and the front vertical wall 4b2 is formed longer in the vertical direction than the rear vertical wall 4b3. The front vertical wall 4b2 is inclined forward and the rear vertical wall 4b3 is inclined rearward. Then, flanges 4b4 and 4b5 are formed extending from the upper ends of the vertical wall portions 4b2 and 4b3 to the front and rear sides. The flanges 4b4 and 4b5 are welded to the flanges 4a1 and 4a2 of the upper member 4a by spot welding or the like. ing.
[0028]
As shown in FIG. 6, the left end side plate-like body 12 is similar to the lower member 4b of the radiator front lower 4 and includes a lower wall portion 12a, a front vertical wall portion 12b, and a rear vertical wall portion 12c. The flanges 12d and 12e extend from the upper ends of the vertical wall portions 12b and 12c to the front and rear sides. Each wall part 12a, 12b, 12c is slightly separated from each wall part 4b1, 4b2, 4b3 of the lower member 4b along the lower surface of the lower member 4b. The flanges 12d and 12e are substantially in contact with the flanges 4b4 and 4b5 of the lower member 4b, and are fixed to the radiator front lower 4 on the right end side. In the present embodiment, the fixing holes 12f formed on the left and right center ends (right end sides) of the flanges 12d and 12e of the left end plate member 12, the flanges 4a1 and 4a2 of the upper member 4a, and the lower member 4b, respectively. The front side of the left frame 1a is fixed to the radiator front lower 4 using bolts 13 that pass through the flanges 4b4 and 4b5. The left end side plate-like body 12 and the right end side plate-like body 13 are formed symmetrically, and the right end side plate-like body 13 has the same configuration as the left end side plate-like body 12, and the description thereof is omitted here.
[0029]
In the subframe 1 configured as described above, the left and right extending portions 6 along the lower surface are located on the lower surface of the radiator front lower 4 of the vehicle body frame 2. Here, since the left-right extending part 6 is formed in a single plate-like body and has a relatively small vertical dimension, the distance from the ground in the front part of the vehicle is relatively large. That is, the right and left extending portion 6 of the present embodiment has a significantly smaller vertical dimension than, for example, a conventionally known one having a hollow closed cross section, and the distance from the ground in the front portion of the vehicle compared to the conventionally known one. Becomes much larger.
[0030]
Further, when the sub-frame 1 is assembled to the vehicle body frame 2, the left frame 1a and the right frame 1b formed in a substantially L shape are separately assembled to the front side members 3 and the radiator front lower 4 respectively. At this time, since the left and right frames 1a and 1b are configured separately from each other, a dimensional error or the like of the subframe 1 or the like is relatively permissible. That is, unlike the conventional one in which the left and right subframe body portions are connected and formed in a substantially U shape, high dimensional accuracy between the subframe body portions is not required when assembling the body frame.
[0031]
Further, since the left and right extending portions 6 of the left frame 1a and the right frame 1b are fixed at two front and rear portions of the radiator front lower 4, the left frame 1a and the right frame 1b are connected via the radiator front lower 4. As a result, when a backward load acts on one of the left frame 1a and the right frame 1b during an offset collision, the load is reliably transmitted to the other frames 1a, 1b and the front side member 3 via the radiator front lower 4. The In the present embodiment, the sub-frame main body 5 is configured to be positioned at substantially the same height as the radiator front lower 4, and the bending moment generated between these members at the time of an offset collision is reduced. A load is smoothly transmitted to the frames 1 a and 1 b 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 at the time of a frontal collision. A load acting rearward is distributed to the frame 1 and the vehicle body frame 2.
[0032]
Further, when a longitudinal compression force is applied to the vehicle due to a frontal collision of the vehicle, the front end side of each subframe main body 5 is easily deformed in the compression direction from the bead 11 as a starting point.
[0033]
Thus, according to the subframe 1 of this embodiment, since the distance from the ground in the front portion of the vehicle is relatively large, a large approach angle of the vehicle can be ensured. In particular, in order to avoid interference with the road surface, it is extremely advantageous in an RV vehicle or the like in which a large approach angle is required for the vehicle, and the degree of freedom in design is drastically improved.
[0034]
Further, according to the subframe 1 of the present embodiment, there is no member located on the lower surface of the radiator front lower 4 at the center side, so that the subframe 1 can be reduced in weight and size, and the vehicle manufacturing cost can be reduced. Can be reduced. Furthermore, not only can the fuel consumption of the vehicle be improved along with the weight reduction of the vehicle, but also the front engine vehicle can be reduced in weight due to the mounting of a prime mover and the like. In addition, traveling performance such as vehicle motion performance can be dramatically improved.
[0035]
Further, according to the subframe 1 of this embodiment, in addition to assembling the left frame 1a and the right frame 1b separately, dimensional errors and the like of the left and right frames 1a and 1b are relatively allowed. 1 can be easily assembled to the body frame 2. In addition, since the left and right frames 1a and 1b are independently configured, it is extremely advantageous when the subframe 1 is transported in a vehicle manufacturing factory or the like.
[0036]
Further, according to the subframe 1 of the present embodiment, at the time of an offset collision of the vehicle, from one of the left frame 1a and the right frame 1b positioned on the collision side to the other frame and the front side member 3 positioned on the non-collision side. As described above, a predetermined offset collision performance can be ensured while increasing the approach angle of the vehicle and reducing the weight of the subframe 1 as described above. It is advantageous.
[0037]
Further, according to the subframe 1 of the present embodiment, the load acting on the rear is distributed to the subframe 1 and the vehicle body frame 2 at the time of a frontal collision of the vehicle. The force in the compression direction is distributed to the side members 3 so that the rear frame 1 and the vehicle body frame 2 as a whole can receive a load rearward efficiently, and the collision performance of the vehicle can be improved.
[0038]
Further, according to the subframe 1 of the present embodiment, when a longitudinal compression force is applied to the vehicle due to a frontal collision of the vehicle or the like, each subframe body 5 can easily be compressed in the compression direction starting from the bead 11. Thus, when a frontal collision of the vehicle or the like occurs, energy such as a collision can be reliably absorbed on the front end side of each subframe main body 5.
[0039]
In the above embodiment, the sub-frame 1 is divided into the left frame 1a and the right frame 1b. However, the plate-like body 6 is disposed on the lower surface of the radiator front lower 4. Needless to say, regardless of the configuration, a large vehicle approach angle is ensured.
[0040]
In addition, the shape and number of the beads 11 in the above embodiment, the fixing structure of the subframe 1 to the vehicle body frame 2 and the like are arbitrary within the scope of achieving the object of the present invention. Of course, it can be changed appropriately.
[0041]
【The invention's effect】
As described above in detail, according to the subframe of the present invention, the distance from the ground in the front portion of the vehicle is made relatively large, so that a large approach angle of the vehicle can be secured.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a vehicle body frame and a sub frame showing a front structure of an automobile according to an embodiment of the present invention.
FIG. 2 is an external perspective view of a left frame of a subframe.
FIG. 3 is a side view showing a sub-frame front main body portion of the left frame.
FIG. 4 is a top view showing a front portion of the left frame.
FIG. 5 is a side cross-sectional view showing a sub-frame front 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-like body of a left subframe.
FIG. 7 is a front sectional view of the front portion of the left subframe.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Subframe 1a Left frame 1b Right frame 2 Body frame 3 Front side member 4 Radiator front lower 5 Subframe main-body part 6 Left-right extension part 11 Bead 12 Left end side plate-like body 13 Right end side plate-like body

Claims (4)

A sub-frame attached to the lower part of a vehicle body frame having a pair of left and right front side members extending substantially front and rear, and a cross member extending from both ends to the front end side of each front side member and extending substantially left and right,
A pair of left and right subframe main bodies connected to the lower surface side of each front side member and extending substantially front and rear;
Extending from the front end side of each of the subframe main body portions to the left and right center side, and having a left and right extending portion disposed on the lower side of the cross member,
A subframe of an automobile, wherein the left and right extending portions are a single plate-like body formed along the lower surface of the cross member. The left and right extending portions have a pair of left and right end plate-like bodies that are respectively connected to the front end sides of the sub-frame main body portions and are respectively located on the lower surfaces on both ends of the cross member,
2. A subframe for an automobile according to claim 1, wherein the subframe is composed of a left frame and a right frame that are independent of each other, each having the subframe main body and the end plate-like body connected to the subframe main body. The left frame and the right frame are fixed to the cross member on the front side and the rear side on the left and right center end sides of the end plate-like body, and the front side member on the front end side of the subframe main body. The automobile subframe according to claim 2, wherein the subframe is fixed to the vehicle. 4. The automobile subframe according to claim 1, wherein a protrusion extending in a direction substantially perpendicular to the front-rear direction is formed on a front end side of each subframe main body. 5.

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