WO2023181248A1

WO2023181248A1 - Vehicle frame structure

Info

Publication number: WO2023181248A1
Application number: PCT/JP2022/013906
Authority: WO
Inventors: 康雄秋本; 渉末廣
Original assignee: 三菱自動車工業株式会社
Priority date: 2022-03-24
Filing date: 2022-03-24
Publication date: 2023-09-28

Abstract

A vehicle frame structure configured by connecting a pair of left and right side members by means of a cross member 10, wherein the side members 5 have an inner member 19 on the inside in the vehicle width direction and an outer member 20 on the outside in the vehicle width direction, the inner member 19 is configured by joining a rear inner member 19b at the rear of the vehicle and a front inner member 19a at the front of the vehicle, the rear inner member 19b is formed of a thin plate-like member that is thinner than the front inner member 19a, and the joined portion of the front inner member 19a and the rear inner member 19b is set forward of a center position in the front-to-rear width of the cross member 10, at the connecting portion of the side members 5 and the cross member 10.

Description

vehicle frame structure

The present invention relates to a vehicle frame structure.

Vehicles such as pickup trucks are equipped with, for example, a pair of side members spaced apart from each other in the vehicle width direction as strength members. Further, the pair of side members are connected by a plurality of cross members extending substantially in the vehicle width direction to form a chassis frame.

Additionally, many vehicles with relatively large payloads, such as pickup trucks, use leaf springs as suspension devices. The front and rear ends of the leaf spring are swingably supported by the side members, respectively. For example, in Patent Document 1, a rear end portion of a leaf spring is supported by a side member via a shackle.

JP2013-79033A

In order to ensure strength and rigidity as well as reduce weight, the side members are often made of, for example, a steel plate and have a rectangular box-like or U-shaped vertical cross section. Furthermore, in order to reduce the weight of vehicles, there is a demand for reducing the thickness of the subframe as much as possible.

However, in the side member, a large load is input from the leaf spring and the cargo box to the connection part with the shackle and the part where the mount bracket is arranged, so it is particularly necessary to ensure sufficient rigidity and strength.

The present invention has been made to solve these problems, and aims to reduce the weight of a vehicle having a chassis frame formed by connecting a pair of left and right side members with a cross member while ensuring the rigidity of the side members. The purpose is to provide a frame structure for a vehicle that can

To achieve the above object, the frame structure of a vehicle of the present invention includes a pair of side members arranged at intervals in the vehicle width direction and extending in the longitudinal direction of the vehicle, and a pair of side members extending in the vehicle width direction. a cross member connecting the pair of side members, the side member having an inner member on the inner side in the vehicle width direction and an outer member on the outer side in the vehicle width direction, and the inner member is connected to a first member on the rear side of the vehicle. and a second member on the front side of the vehicle that is longer in length than the first member, and the cross member is configured to cover a joint between the first member and the second member in the inner member. The joint portion between the first member and the second member is located forward of a center position of the width of the cross member in the longitudinal direction of the vehicle.

Thereby, the inner member can be divided into the first member and the second member to shorten the length of the parts, thereby improving the yield of the parts and reducing the cost of the parts.
Furthermore, since the cross member is connected to cover the joint between the first member and the second member, the strength of the side member at the joint between the first and second members can be ensured.
Additionally, by locating the joint between the first and second members on the front side of the cross member, which is more likely to twist and deform than the rear side of the cross member when the vehicle is driving on rough roads, this joint can be firmly fixed. By doing so, the rigidity of the entire frame including the side members and cross members can be efficiently improved and deformation can be suppressed.

Preferably, the cross member is disposed at the rearmost of a plurality of cross members provided in the vehicle that connect the pair of side members, and the first member is arranged at least at the rearmost part of the cross members of the second member. It is preferable that the thickness is thinner than the portion adjacent to the first member.
As a result, by reducing the thickness of the first member that extends rearward from the rearmost cross member, the weight of the side member is reduced, and the first member collapses in the event of a rear-end collision of the vehicle, making it easier to absorb the collision load. Can be done.

Preferably, the first member is thinner than a portion of the outer member adjacent to the outer side of the first member in the vehicle width direction, and a portion of the first member is thinner than a portion of the outer member adjacent to the outer side of the first member in the vehicle width direction. It is preferable that the outer member is formed wider in the vehicle width direction than the outer member adjacent to the outside.
As a result, by having a portion in the first member that is thinner than the outer member and has a larger width in the vehicle width direction, the side member can be easily crushed in the thinner portion of the first member in the event of a rear collision of the vehicle. can. Therefore, it is possible to further improve the shock absorbability in the event of a rear collision.

Preferably, the first member is configured such that the width in the vehicle width direction increases toward the rear of the vehicle.
As a result, the weight of the rear part of the side member can be further reduced, and the rear part of the side member can be more easily crushed in the event of a rear collision, thereby further improving shock absorption.

Preferably, the width in the vehicle width direction of the rear end portion of the first member is the same as the width in the vehicle width direction of the rear end portion of the side member.
Thereby, by making the rear end portion of the side member substantially the first member, it is possible to further reduce the weight of the side member.

Preferably, the side member further includes a reinforcement extending in the vehicle width direction and connecting inner walls on both sides in the vehicle width direction, and the reinforcement is provided at a connection portion between the side member and the cross member. It is recommended that the vehicle be placed at the front and rear positions of the vehicle.
Thereby, the rigidity and strength of the connection portion between the side member and the cross member can be improved by reinforcement.

According to the vehicle frame structure of the present invention, the part length of the inner member is shortened to reduce parts cost, and the cross member ensures the rigidity of the side member at the joint between the first member and the second member. be able to.

Furthermore, since the joint between the first member and the second member is located in front of the center position of the longitudinal width of the cross member, the first A connecting portion between the member and the second member is arranged. By firmly fixing this connecting portion, the rigidity of the entire frame including the side members and cross member can be efficiently improved and deformation can be suppressed.

FIG. 1 is a perspective view schematically showing the structure of a lower rear portion of a vehicle according to an embodiment of the present invention. FIG. 1 is a perspective view showing a schematic structure of a chassis frame of a vehicle according to the present embodiment. It is a perspective view showing the structure of the attachment part of the cargo box in the rear part of the side member concerning this embodiment. FIG. 3 is a perspective view showing a structure near a connecting portion between a left side member and a rearmost cross member according to the present embodiment. FIG. 3 is a top view showing the structure near the connection portion between the left side member and the rearmost cross member according to the present embodiment.

Embodiments of the present invention will be described below based on the drawings.
FIG. 1 is a perspective view showing a schematic structure of a lower rear portion of a vehicle 1 according to an embodiment of the present invention. FIG. 2 is a perspective view showing a schematic structure of the chassis frame 2 of the vehicle 1 according to the present embodiment. FIG. 3 is a perspective view showing the structure of the mounting portion of the cargo box 4 at the rear of the side member according to the present embodiment.

A vehicle 1 according to an embodiment employing the frame structure of the present invention is a vehicle equipped with a cargo box 4 and a suspension device 8 using leaf springs 11, such as a pickup truck, for example.

As shown in FIGS. 1 and 2, the vehicle 1 includes a pair of

side members

5 and 6 that extend in the longitudinal direction of the vehicle and are spaced apart from each other in the vehicle width direction. Further, the pair of

side members

5 and 6 are connected by a plurality of cross members to form the chassis frame 2. The cross members extend in the vehicle width direction and are arranged at intervals in the vehicle longitudinal direction.
A cargo box 4 is placed on the chassis frame 2. The cargo box 4 is fixed to a mount bracket 3 fixed to the

side members

5 and 6 with bolts and nuts (not shown).

A plurality of mount brackets 3 are provided on the outside of the

side members

5 and 6 in the vehicle width direction and spaced apart from each other in the vehicle longitudinal direction. Among the plurality of mount brackets 3, the mount bracket 3 disposed at the rearmost position of the vehicle is provided near the rearmost cross member 10 at the longitudinal position of the vehicle.

Further, the axle of the rear wheel 7 of the vehicle 1 is suspended by a suspension device 8 using a leaf spring 11.
The leaf springs 11 are arranged below the

side members

5 and 6 so as to extend in the direction in which the

side members

5 and 6 extend, that is, in the longitudinal direction of the vehicle. The front end portion of the leaf spring 11 is rotatably supported in the vehicle vertical direction by the

side members

5 and 6 via a front connecting shaft (not shown).

The rear end portion of the leaf spring 11 is rotatably supported by the

side members

5 and 6 via a shackle 12 in the vertical direction of the vehicle. The shackle 12 is supported by the

side members

5 and 6 behind and near the cross member 10.

The shackle 12 is connected to the

side members

5, 6 by a shackle pin 41 inserted into an insertion hole 13 extending in the vehicle width direction provided in the side wall of the

side members

5, 6, and supported rotatably around the insertion hole 13. At the same time, the rear end portion of the leaf spring 11 is supported rotatably about an axis extending in the vehicle width direction.

The

side members

5 and 6 are formed by abutting and welding both ends of an inner member 19 and an outer member 20, which are formed by bending a sheet metal member into a U-shape. The

side members

5 and 6 are hollow and have a box-shaped longitudinal section, and have an upper wall 21, a lower wall 22, an inner wall 23, and an outer wall 24. The upper wall 21 and the lower wall 22 have a weld line 25 which is a butt portion between the inner member 19 and the outer member 20.

The cross member 10 has a hollow shape with a box-shaped cross section, and has an upper wall 26, a lower wall 27, a front wall 28, and a rear wall 29.
The end of the cross member 10 is abutted against an inner wall 23 of the side member on the inner side in the vehicle width direction and is fixed by welding.

As shown in FIG. 3, the mount bracket 3 has a U-shaped upper and lower cross section, and has an upper wall 30 and two supporting

side walls

31 and 32. The mount bracket 3 is arranged such that the upper wall 30 and supporting

side walls

31 and 32 extend perpendicularly from the outer walls 24 of the

side members

5 and 6 in the vehicle width direction. The upper wall 30 of the mount bracket 3 has approximately the same vertical height as the upper wall 21 of the

side members

5 and 6, and is arranged to extend in the horizontal direction of the vehicle 1. They are arranged so that they are spaced apart from each other in the direction. Therefore, the opening of the mount bracket 3, which has a U-shaped cross section, is arranged so as to face downward.

Ends of the supporting

side walls

31 and 32 of the mount bracket 3 on the

side members

5 and 6 are bent vertically outward in the longitudinal direction of the vehicle to provide outer flange portions 35, respectively. The outer flange portion 35 faces the outer wall 24 of the side member, and its outer peripheral portion is fixed to the outer wall 24 by welding. Further, the outer flange portion 35 of the mount bracket 3 has an outer end portion cut out in a substantially semicircular shape to form a cutout portion 36 .

A bolt hole 37 is provided in the upper wall 30 of the mount bracket 3, and a bolt hole 37 is provided in a strength member at the bottom of the packing box 4, or a bolt hole provided in a mount bracket fixed to the bottom of the packing box 4. By inserting bolts into the bolt holes and tightening them together, the cargo box 4 and the

side members

5 and 6 are removably fixed via the mount bracket 3.

4 and 5 show the structure near the connection between the side member 5 and the cross member 10 according to the embodiment of the present invention, with FIG. 4 being a perspective view and FIG. 5 being a top view. Note that FIG. 4 is a view of the connecting portion between the side member 5 on the left side in the vehicle width direction and the rearmost cross member 10, viewed from approximately the center in the vehicle width direction and from the rear.

The side member 5 is provided with a cylindrical portion 40 that connects the shackle 12 near the rear of the cross member 10. The cylindrical part 40 is a cylindrical member, arranged so that its axis extends in the vehicle width direction and passes through the side member 5, and has an insertion hole 13 formed therein into which a circular rod-shaped shackle pin 41 is inserted. There is. The shackle 12 has a pair of plate members whose one end portions are arranged to sandwich the side member 5 from side to side, and the one end portion of the shackle 12 is rotatably supported by the side member 5 in the front-rear direction by a shackle pin 41. be done. Both ends of the cylindrical portion 40 are respectively arranged so as to slightly protrude outward from the side walls (inner wall 23, outer wall 24) of the side member 5, and are fixed to the side wall of the side member 5 by, for example, welding. There is.

The inner end of the cylindrical portion 40 is provided with a reinforcing portion 45 that protrudes radially outward from the outer peripheral wall of the cylindrical portion 40 . The reinforcing part 45 is a plate-like member having a hole into which the inner end of the cylindrical part 40 is inserted, and is fixed all around by welding to the outer peripheral surface of the inner end of the cylindrical part 40 . Further, the reinforcing portion 45 faces the inner wall 23 of the side member 5 and is fixed by welding. Therefore, one end portion of the cylindrical portion 40 is fixed to the side member 5 via the reinforcing portion 45.

Furthermore, the reinforcing portion 45 extends linearly toward the front of the vehicle along the inner surface of the side member 5 to a position close to the rear wall 29 of the cross member 10. Further, the supporting side wall 31 of the vehicle rearmost mount bracket 3 on the vehicle rear side is arranged at a vehicle longitudinal position between the rear wall 29 of the vehicle rearmost cross member 10 and the front end of the reinforcing portion 45. Note that the reinforcing portion 45 may extend toward the front of the vehicle until it comes into contact with the rear wall 29 of the cross member 10. Further, the rear wall 29 of the cross member 10, the front end of the reinforcing portion 45, and the support side wall 31 on the rear side of the vehicle of the mount bracket 3 at the rear of the vehicle may be arranged so that the longitudinal positions of the vehicle substantially coincide with each other or in the vicinity. .

Further, the inner member 19 on the inside in the vehicle width direction of the side member 5 is located between the front wall 28 and the rear wall 29 of the cross member 10 and in a position forward of the center position in the longitudinal direction of the cross member 10, on the front side of the vehicle. It is divided into an inner member 19a (second member) and a rear inner member 19b (first member) on the rear side of the vehicle. The rear end of the front inner member 19a and the front end of the rear inner member 19b are joined by welding (joint portion 38).
Furthermore, the rear inner member 19b is formed thinner than the front inner member 19a and the outer member 20.

Further, the rear inner member 19b is located at a position rearward from the cylindrical portion 40, and its length in the vehicle width direction gradually increases linearly as it extends toward the rear of the vehicle. The length in the vehicle width direction gradually decreases as it extends rearward. As a result, in the side member 5, the proportion occupied by the rear inner member 19b becomes larger than that of the outer member 20 as the side member 5 moves toward the rear of the vehicle from the cylindrical portion 40. At the rear end of the side member 5, the outer member 20 has only an outer wall 24 without substantially having an upper wall 21 or a lower wall 22, and the width of the rear inner member 19b in the vehicle width direction is equal to the width of the side member 5 in the vehicle width direction. are almost the same.

Inside the side member 5 near the connection part with the cross member 10, two

reinforcements

50 and 51 are placed apart from each other in the longitudinal direction of the vehicle, which is the extension direction of the side member 5, and reinforce the side member 5. It is provided.

The

reinforcements

50 and 51 are rectangular thick plate members, and the entire circumference is welded and fixed to the inner wall of the side member 5. That is, the

reinforcements

50 and 51 have the effect of supporting the inner wall of the side member 5 and improving the strength and rigidity of the side member 5.

The reinforcement 50 on the rear side of the vehicle is arranged at a longitudinal position of the vehicle between the rear wall 29 of the rearmost cross member 10 of the vehicle and the front end of the reinforcing portion 45. The reinforcement 50 on the rear side of the vehicle is arranged at substantially the same position or in the vicinity of the rear wall 29 of the cross member 10, the front end of the reinforcing portion 45, and the support side wall 31 of the mount bracket 3 on the rear side of the vehicle. It's okay.

On the other hand, the reinforcement 51 on the front side of the vehicle is located slightly behind the front wall 28 of the cross member 10 and slightly forward of the joint 38 between the front inner member 19a and the rear inner member 19b.

The reinforcement 50 has a two-part structure including an inner reinforcement 50a fixed to the inner member 19 and an outer reinforcement 50b fixed to the outer member 20. The inner reinforcement 51a is fixed to the inside of the inner member 19 by welding, and the outer reinforcement 51b is fixed to the inside of the outer member 20 by welding.
In the above embodiment, the structure of the left side member 5 of the vehicle has been described, but the right side member 6 of the vehicle may also have a symmetrical and similar structure.

As described above, in this embodiment, the

side members

5 and 6 are constituted by an inner member 19 on the inside in the vehicle width direction and an outer member 20 on the outside in the vehicle width direction. Furthermore, the inner member 19 is formed by welding together parts that are divided in the longitudinal direction of the vehicle, such as a front inner member 19a on the front side of the vehicle and a rear inner member 19b on the rear side of the vehicle.
Thereby, the component length of the inner member 19 can be shortened, so that the yield of components can be improved and component costs can be reduced.

Further, at the connection portion between the inner member 19 and the cross member 10, specifically, the front inner member 19a and the rear inner member 19b are joined at a vehicle longitudinal position between the front wall 28 and the rear wall 29 of the cross member 10. Since the cross member 10 is connected to cover the joint 38 between the front inner member 19a and the rear inner member 19b, the strength and rigidity of the

side members

5 and 6 can be ensured.

The inner member 19 is constructed by joining a rear inner member 19b on the rear side of the vehicle and a front inner member 19a on the front side of the vehicle, which is longer than the rear inner member 19b. Therefore, for example, due to the input from the rear tire that is loaded during off-road driving, the front periphery of the connecting portion between the

side members

5, 6 and the cross member 10 has a structure that tends to undergo torsional deformation relative to the rear periphery. It becomes. According to this configuration, the width in the vehicle longitudinal direction of the cross member 10 is located at the front of the connection between the

side members

5 and 6 and the cross member 10, where deformation is likely to occur, that is, near the rear tire, and where the contribution to torsional rigidity is high. The rigidity of the entire chassis frame 2 including the

side members

5, 6 and the cross member 10 can be increased by arranging the joint portion where the front inner member 19a and the rear inner member 19b are stacked in front of the center position. It is possible to improve efficiency and suppress deformation.

Further, since the cross member 10 at the longitudinal position where the front inner member 19a and the rear inner member 19b are joined is disposed at the rearmost of the plurality of cross members of the vehicle 1, the cross member 10 at the rearmost position The thickness of the rear inner member 19b, which extends further to the rear, is thinner than that of the front inner member 19a. This makes it possible to reduce the weight of the inner member 19, and by extension the

side members

5 and 6, and to make it easier to absorb the collision load by crushing the rear inner member 19b in the event of a rear collision of the vehicle.

Furthermore, since the outer member 20 is thicker than the rear inner member 19b, the outer member 20 can ensure the required rigidity and strength while reducing the weight by using the thinner rear inner member 19b.

The width in the vehicle width direction of the rear inner member 19b is approximately the same as the width in the vehicle width direction of the outer member 20 at the connection position with the cross member 10, and the width in the vehicle width direction increases toward the rear end behind the cylindrical portion 40. It has become. Therefore, behind the cylindrical portion 40, the width in the vehicle width direction of the thin rear inner member 19b is equal to or larger than the width in the vehicle width direction of the outer member 20, and the

side members

5 and 6 can be easily crushed. This makes it possible to improve shock absorption in the event of a rear collision.

In particular, at the rear end portions of the

side members

5, 6, the width of the rear inner member 19b in the vehicle width direction is approximately the same as the width of the

side members

5, 6 in the vehicle width direction. can be further reduced in weight.

Furthermore, since the width of the front inner member 19a in the vehicle width direction increases linearly rather than stepwise toward the rear ends of the

side members

5 and 6, stress concentration in the

side members

5 and 6 can be suppressed. can. Therefore, the rear end portions of the

side members

5 and 6 are more likely to be crushed uniformly in the event of a rear collision, and the shock absorbability can be further improved.

In addition, two

reinforcements

50 and 51 are provided in the

side members

5 and 6 near the connection part of the cross member 10 at an interval in the longitudinal direction of the vehicle, so that the

reinforcements

50 and 51 near the connection part with the cross member 10 are The strength and rigidity of the

side members

5 and 6 can be improved. Therefore, even if stress occurs in the connection portion of the

side members

5, 6, deformation of the cross section of the

side members

5, 6 can be suppressed. Thereby, the torsional rigidity of the

side members

5 and 6 can be improved, and the maneuverability of the vehicle can be improved.

Of the two

reinforcements

50 and 51 provided near the connection part of the cross member 10, the reinforcement 51 on the front side of the vehicle is arranged near the joint part 38 between the front inner member 19a and the rear inner member 19b. Therefore, the strength and rigidity of the

side members

5 and 6 near the joint 38 between the front inner member 19a and the rear inner member 19b can be improved.

Further, the outer flange portion 35 of the mount bracket 3 has a substantially semicircular cutout at its outer end to form a cutout portion 36, so that the outer flange portion 35 and the outer wall 24 of the side member are fixed. It is possible to secure a long welding length for this purpose. Furthermore, by extending the upper part of the outer flange portion 35 on the rear side of the vehicle closer to the cylindrical portion 40, the distance between the support portion of the leaf spring 11 and the mount bracket 3 is shortened, and the rigidity near the cylindrical portion 40 is reduced. can be improved.

The present invention is not limited to the embodiments described above.
For example, in the above embodiment, the rear inner member 19b is thinner than the front inner member 19a and the outer member 20, but it may be made thinner in only a portion.

Further, in the above embodiment, the joint portion 38 between the front inner member 19a and the rear inner member 19b is arranged at the connection portion between the cross member 10 and the

side members

5 and 6 at the rearmost portion of the vehicle. The joint between the front inner member 19a and the rear inner member 19b may be arranged at the joint between the front inner member 19a and the rear inner member 19b.

Further, the detailed structures of the

side members

5, 6, cross member 10, etc. may be changed as appropriate.
Regarding the vehicle 1, the present invention can also be widely applied to vehicles having a chassis frame configured by connecting a pair of side members with a cross member.

1

Vehicle

5, 6 Side member 10 Cross member 19 Inner member 19a Front inner member (second member)
19b Rear inner member (first member)
20

Outer member

50, 51 Reinforce

Claims

a pair of side members arranged at intervals in the vehicle width direction of the vehicle and extending in the longitudinal direction of the vehicle;
a cross member extending in the vehicle width direction and connecting the pair of side members;
The side member has an inner member on the inner side in the vehicle width direction and an outer member on the outer side in the vehicle width direction,
The inner member is configured by joining a first member on the rear side of the vehicle and a second member on the front side of the vehicle that is longer in length than the first member,
The cross member is connected to cover a joint between the first member and the second member in the inner member,
A frame structure for a vehicle, wherein a joint between the first member and the second member is located forward of a center position of the width of the cross member in the longitudinal direction of the vehicle.
The cross member is arranged at the rearmost of a plurality of cross members of the vehicle connecting the pair of side members, and the first member is adjacent to at least the first member of the second members. The vehicle frame structure according to claim 1, wherein the frame structure is thinner than the portion.
The first member is formed to be thinner than a portion of the outer member adjacent to the outside of the first member in the vehicle width direction,
The vehicle frame according to claim 1 or 2, wherein a portion of the first member is formed wider in the vehicle width direction than the outer member adjacent to the outer side of the first member in the vehicle width direction. structure.
4. The vehicle frame structure according to claim 3, wherein the first member is configured such that the width in the vehicle width direction increases toward the rear of the vehicle.
The vehicle frame structure according to claim 3 or 4, wherein the width in the vehicle width direction of the rear end portion of the first member is the same as the width in the vehicle width direction of the rear end portion of the side member.
The side member further has reinforcement therein that extends in the vehicle width direction and connects inner walls on both side surfaces in the vehicle width direction,
The vehicle frame structure according to any one of claims 1 to 5, wherein the reinforcement is arranged at a connecting portion between the side member and the cross member.