WO2023181249A1

WO2023181249A1 - Bottom structure of vehicle

Info

Publication number: WO2023181249A1
Application number: PCT/JP2022/013907
Authority: WO
Inventors: 康雄秋本; 光城; 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

The present invention is a bottom structure of a vehicle in which a rear section of a leaf spring 11 is linked via a shackle to a position further back on the vehicle than a connection section connecting a cross member 10 to the rearmost section of a side member 5. The bottom structure comprises: a tubular part 40 which passes through and is affixed to a side surface of the side member 5 in the vehicle width direction and into which a shackle pin is inserted; and a reinforcing part 45 provided so as to surround the tubular part 40 at the vehicle width direction inner side end of the tubular part 40. The reinforcing part 45 includes a first portion 45a which extends in the vehicle forward direction towards the cross member 10, and a second portion 45b which is provided contiguous with the first portion 45a, extends in the vehicle rear direction, and has a hole into which the vehicle width direction inner side end of the tubular part 40 is inserted.

Description

Vehicle undercarriage

The present invention relates to the structure of a support portion of a vehicle suspension device.

2. Description of the Related Art Vehicles such as pickup trucks include, 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 in the vehicle width direction to form a chassis frame.
Additionally, many vehicles such as pickup trucks that carry relatively large loads use leaf springs as suspension devices. The front and rear ends of the leaf spring are each swingably locked to the side member. For example, in Patent Document 1, a rear end portion of a leaf spring is supported by a side member via a shackle. A cylindrical pin is inserted into a circular hole provided in the side member so as to extend in the vehicle width direction, and the side member and the shackle are connected by the pin so as to be swingable in the vertical direction.

Japanese Patent Application Publication No. 2003-306019

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

However, in the side member, a large load is input from the leaf spring to the connection part with the shackle, so in order to improve vehicle handling and ride comfort, sufficient rigidity of the side member, especially near this connection part, must be ensured. There is a need to.

The present invention has been made in order to solve such problems.In a vehicle that has a chassis frame formed by connecting a pair of left and right side members with a cross member, and supports a leaf spring on the side member, the leaf spring The object of the present invention is to provide a vehicle undercarriage structure that improves the rigidity of the support part of the vehicle.

In order to achieve the above object, the lower 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 vehicle longitudinal direction, and a pair of side members extending in the vehicle width direction. , a cross member connecting the pair of side members, a leaf spring disposed along the pair of side members and supporting an axle of the vehicle, and one end of the leaf spring being rotatable to the side member. a connecting shaft that connects, and the side member and the connecting shaft are a lower structure of a vehicle that is connected at a position spaced apart in the longitudinal direction of the vehicle from a connecting portion between the side member and the cross member, a cylindrical part that is fixed to pass through a side surface of the side member in the vehicle width direction, and into which the connecting shaft is rotatably inserted into the side member; and at least one end side of the cylindrical part. a reinforcing portion provided on the side surface of the side member so as to surround the cylindrical portion, the reinforcing portion including a first portion extending in a first direction toward the cross member; and a second portion that is continuously provided and extends in a second direction opposite to the first direction.

As a result, the connecting portion between the side member and the connecting shaft, that is, the supporting portion of the leaf spring has a structure in which a load is input from the leaf spring to the side member via the connecting shaft and the cylindrical portion, but the cylindrical portion Since the reinforcing portion is provided on the side surface of the side member so as to surround the cylindrical portion on one end side of the side member, the rigidity of the support portion of the leaf spring can be increased. In particular, since the reinforcing portion has a first portion extending toward the cross member and a second portion provided continuously to the first portion and extending in the opposite direction to the first portion, the reinforcing portion has a cylindrical shape. The rigidity of the side member near one end of the section and between the cylindrical section and the cross member can be increased, and the rigidity of the side member against the load received from the leaf spring can be effectively increased.

Preferably, the reinforcing portion holds the one end portion of the cylindrical portion.
Thereby, the reinforcing portion can hold the cylindrical portion with respect to the side member without wobbling.

Preferably, the reinforcing portion is provided at an inner end in the vehicle width direction of both ends of the cylindrical portion.
As a result, the reinforcing part is provided on the side member at the inner end in the vehicle width direction near the cross member of both ends of the cylindrical part, so the rigidity of the side member near the support part of the leaf spring is increased. can be effectively increased.

Preferably, the second portion has a substantially annular shape surrounding the cylindrical portion.
Thereby, the space occupied by the second portion can be suppressed, and the rigidity of the side member near the support portion of the leaf spring can be increased.

Preferably, the first portion is arranged to extend linearly in the direction in which the side members extend toward the cross member.
This makes it possible to reduce the length of the first portion of the reinforcing portion to reduce the weight of the vehicle, while bringing the first portion closer to the cross member and increasing the rigidity near the support portion of the leaf spring.

Preferably, the width of the first portion and the second portion in a direction perpendicular to the extending direction of the side member is larger than that of the cylindrical portion.
Thereby, the rigidity of the side member near the cylindrical portion can be greatly increased by the first portion and the second portion of the reinforcing portion.

Preferably, the side member is formed of a member having a thinner plate thickness at a portion closer to the cylindrical portion than the connection position with the cross member in the extension direction than at a portion on the opposite side to the cylindrical portion. .
This makes it possible to reduce the thickness of the portion of the side member on the cylindrical portion side, thereby reducing the weight. Since the reinforcing portion is provided in the portion of the side member on the cylindrical portion side, rigidity is ensured even if the portion is made thin.

Preferably, the cross member is disposed at the rearmost of a plurality of cross members of the vehicle connecting the pair of side members, and the cylindrical portion is disposed behind the cross member in the vehicle. Good to have.
Thereby, the reinforcing portion is configured to extend forward of the vehicle from the cylindrical portion toward the rearmost cross member. Therefore, the rigidity of the side member near the cylindrical portion disposed at the rear of the vehicle can be improved, and the rigidity against the load acting on the side member from the support portion of the leaf spring disposed at the rear of the vehicle can be improved. In addition, if the part of the side member closer to the cylindrical part than the connection position with the cross member is formed of a thinner member than the part on the opposite side to the cylindrical part, the part of the side member that is closer to the cylindrical part than the connection position with the cross member is The weight of the side member can be significantly reduced by reducing the thickness of the rear portion.

Preferably, the side member is a hollow member, and has reinforcement therein that extends in the vehicle width direction and connects inner walls on both side surfaces in the vehicle width direction, and the reinforcement is provided in the reinforcing portion and the reinforcement portion. It is preferable to arrange it at a position in the front and rear of the vehicle between the cross member and the cross member.
Thereby, the rigidity of the side member near the connecting portion with the cross member and the supporting portion of the leaf spring can be increased by the reinforcement.

Preferably, the vehicle includes a mount bracket for fixing the cargo box to the side member, and the mount bracket is disposed at a longitudinal position of the vehicle between the reinforcing portion and the cross member.
Thereby, the load received by the support portion of the leaf spring can be transmitted to the cargo box via the mount bracket. Therefore, the rigidity of the support portion of the leaf spring can be further increased by using the packing box.

According to the vehicle lower structure of the present invention, the rigidity of the support portion of the leaf spring can be increased by the reinforcing portion provided on the side surface of the side member. Thereby, it is possible to improve the maneuverability and ride comfort of the vehicle.

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. 2 is a perspective view showing the lower structure near the rear support portion of the left leaf spring and the connection portion between the left side member and the rearmost cross member according to the present embodiment. FIG. 7 is a top view showing the lower structure near the rear support portion of the left leaf spring and 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 employing the lower structure of the present invention is a vehicle equipped with 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 are 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 in the vehicle longitudinal position.

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 and 6 by a shackle pin 41 (connection shaft) inserted into an insertion hole 13 extending in the vehicle width direction provided in the side wall of the

side members

5 and 6, and rotates around the insertion hole 13. The leaf spring 11 is movably supported, and has a structure in which the rear end portion of the leaf spring 11 is rotatably supported around 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 that 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 longitudinal section, and has an upper wall 26, a lower wall 27, a front wall 28, and a rear wall 29.
The ends of the cross member 10 are abutted against the inner walls 23 of the

side members

5 and 6 on the inner side in the vehicle width direction, and are fixed by welding.

As shown in FIG. 3, the mount bracket 3 has a U-shaped vertical cross section and includes 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 end of the outer flange portion 35 of the mount bracket 3 is cut out in a substantially semicircular shape to form cutout portions 36, respectively.

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 are diagrams showing the lower structure near the rear support portion of the left leaf spring 11 and the connection portion between the left side member 5 and the rearmost cross member 10 according to the embodiment of the present invention. . FIG. 4 is a perspective view, and FIG. 5 is a top view. Note that FIG. 4 is a view of the vicinity of the connection between the side member 5 on the left side in the vehicle width direction and the rearmost cross member 10 as viewed from approximately the center in the vehicle width direction of the vehicle 1 and from the upper 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 vertical 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.

A reinforcing portion 45 that protrudes outward in the radial direction from the outer circumferential wall of the cylindrical portion 40 is provided on the inner end (one end) side of the cylindrical portion 40 in the vehicle width direction. 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 . The reinforcing portion 45 includes a first portion 45a that extends toward the front of the vehicle (first direction) toward the cross member 10, and a second portion 45b that is provided continuously with the first portion 45a and extends toward the rear of the vehicle (second direction). It has .

The second portion 45b has a substantially annular shape and has a hole into which the inner end of the cylindrical portion 40 is inserted, and is in contact with the inner wall 23 of the side member 5 and fixed by welding. Therefore, one end portion of the cylindrical portion 40 is fixed to the side member 5 via the reinforcing portion 45.

The first portion 45a extends linearly toward the front of the vehicle from the second portion 45b to a position close to the rear wall 29 of the cross member 10 along the inner surface of the side member 5. 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 first portion 45a of 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 and a rear inner member 19b 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 connected by welding (connection 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 an upper wall 21 or a lower wall 22, and the width of the rear inner member 19b in the vehicle width direction is the width of the side member 5 in the vehicle width direction. are almost the same.

Inside the

side members

5 and 6 near the connection part with the cross member 10, two reinforcements 50 are arranged to be spaced 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. 51 are provided.

The

reinforcements

50 and 51 are rectangular thick plate members, and their entire circumferences are 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. Note that the rear wall 29 of the cross member 10, the front end of the reinforcing portion 45, the support side wall 31 of the mount bracket 3 on the rear side of the vehicle, and the reinforcement 50 on the rear side of the vehicle are arranged at substantially the same or nearby vehicle longitudinal positions. You can.

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 connection position between the front inner member 19a and the rear inner member 19b.

The reinforcement 50 has a two-part structure consisting of 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. When manufacturing the side member 5 by welding the inner member 19 and the outer member 20, the inner reinforcement 51a and the outer reinforcement 51b are partially overlapped and connected to each other by welding at the overlapped portion.

Similarly to the reinforcement 50 on the rear side of the vehicle, the reinforcement 51 on the front side of the vehicle is also configured by connecting an inner reinforcement 51a and an outer reinforcement 51b.
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 reinforcing portion extends along the inner wall 23 of the

side members

5 and 6 so as to surround the inner end in the vehicle width direction of the cylindrical portion 40 into which the shackle pin 41 is inserted. It is equipped with 45. As a result, the rigidity of the support part of the leaf spring 11 of the vehicle 1 is increased, and the vicinity of the connection part between the shackle 12 and the

side members

5 and 6, that is, the rear end support part of the leaf spring 11 which is the suspension device 8 of the rear wheel 7. The rigidity of the

side members

5 and 6 can be increased. Therefore, it is possible to improve the maneuverability and ride comfort of the vehicle 1.

Further, the reinforcing portion 45 includes a second portion 45b surrounding the cylindrical portion 40, and a first portion 45a extending toward the front of the vehicle (in the first direction) from the second portion 45b to the vicinity of the cross member 10. Since the portion 45a and the second portion 45b are one continuous plate member, the rigidity of the

side members

5 and 6 between the cylindrical portion 40 and the cross member 10 can be increased with a simple structure. Therefore, the rigidity of the

side members

5 and 6 against the load received from the leaf spring 11 can be effectively increased.

Further, the second portion 45b of the reinforcing portion 45 and the cylindrical portion 40 are fixed by welding, and the reinforcing portion 45 holds the cylindrical portion 40. On the other hand, the cylindrical portion 40 can be held without wobbling.

Further, among both ends of the cylindrical portion 40 extending in the vehicle width direction, a reinforcing portion 45 is provided at the inner end in the vehicle width direction near the cross member 10, so that the leaf spring 11 acts on the cylindrical portion 40. The cross member 10 effectively suppresses deflection due to the load, and the rigidity of the support portion of the leaf spring 11 can be more effectively increased with a small number of reinforcing portions 45.

Further, since the second portion 45b of the reinforcing portion 45 has a substantially annular shape surrounding the cylindrical portion 40, for example, the first portion 45a and the second portion 45b of the reinforcing portion 45 together have a rectangular shape. Compared to the case in which the second portion 45b is used, the space occupied by the second portion 45b can be suppressed, and the support portion of the leaf spring 11 can be reinforced.

Further, since the reinforcing portion 45 extends linearly from the cylindrical portion 40 toward the cross member 10 in the longitudinal direction of the vehicle, which is the direction in which the

side members

5 and 6 extend, the length of the reinforcing portion 45 can be suppressed. The extension end can be brought closer to the cross member 10. Thereby, the rigidity of the support portion of the leaf spring 11 can be increased while suppressing the weight increase due to the reinforcing portion 45.

Further, since the width of the first portion 45a and the second portion 45b of the reinforcing portion 45 in the vertical direction (in the direction perpendicular to the extending direction of the side members 5 and 6) is formed larger than that of the cylindrical portion 40, The rigidity of the

side members

5 and 6 can be greatly increased. Further, since the reinforcing part 45 is configured to include the cylindrical part 40 within its vertical width, the stiffness of the

side members

5 and 6 near the cylindrical part 40 is efficiently and greatly increased by the reinforcing part 45. be able to.

Further, among the

side members

5 and 6, the inner member 19 on the inside of the vehicle is divided into a front inner member 19a and a rear inner member 19b. The inner member 19 is formed by being connected to the member 19b.

Of the front inner member 19a and the rear inner member 19b, the rear inner member 19b on the side closer to the cylindrical part 40 than the connection position with the cross member 10 is thinner than the front inner member 19a on the opposite side to the cylindrical part 40. It is made of a thick plate member.

This makes it possible to reduce the weight of the rear inner member 19b, and also improves collision performance by making the rear end of the side member more likely to collapse. Further, even if the rear inner member 19b is made thinner, the rigidity of the

side members

5 and 6 near the cylindrical portion 40 is ensured.

Further, the cross member 10 is disposed at the rearmost of the plurality of crossmembers provided in the vehicle 1, and the cylindrical portion 40 is disposed at the rear of the cross member 10 in the vehicle. In the supporting portion of the leaf spring 11 supported behind the cross member 10, the stiffness of the

side members

5 and 6 near the cylindrical portion 40 can be increased by the reinforcing portion 45. Here, since the rear inner member 19b is formed of a member having a thinner thickness than the outer member 20 and the front inner member 19a, the rear inner member 19b is located behind the rear support portion of the leaf spring 11, which is less likely to receive a relatively large load while the vehicle is running. By reducing the plate thickness of the

members

5 and 6, the weight of the

side members

5 and 6 can be significantly reduced.

In addition, since 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, the side members near the connection part of the cross member 10 The strength and rigidity of Nos. 5 and 6 can be further 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, it is possible to improve the torsional rigidity of the

side members

5 and 6 in the vicinity of the connecting portion of the cross member 10 and the rear support portion of the leaf spring 11, thereby improving the maneuverability of the vehicle.

Of the two

reinforcements

50 and 51 provided near the connection portion of the cross member 10, the reinforcement 50 on the rear side of the vehicle is located between the rear wall 29 of the cross member 10 and the front end of the reinforcing portion 45. The strength and rigidity of the

side members

5, 6 near the connection portion between the rear wall 29 of the cross member 10 and the

side members

5, 6 and near the support portion of the leaf spring 11 can be improved. .

Further, the reinforcement 50 on the rear side of the vehicle, the supporting side wall 31 of the mount bracket 3 on the rear side of the vehicle, and the rear wall 29 of the cross member 10 are arranged so as to be connected substantially in a straight line by the reinforcement 50, and the cross member 10 Since the reinforcing portion 45 extends to the vicinity of the rear wall 29, the load input from the leaf spring 11 of the suspension device 8 can be distributed to the

side members

5, 6 and the cross member 10. Specifically, the power is transmitted from the inner end of the cylindrical portion 40 in the vehicle width direction to the cross member 10 via the reinforcing portion 45 and the inner member 19, while the power is transmitted from the outer end of the cylindrical portion 40 in the vehicle width direction to the outer member 20. It is also transmitted to the strength member at the bottom of the cargo box 4 via the mount bracket 3. Thereby, the rigidity of the support portion of the leaf spring 11 can be further improved by using the packing box 4.

Furthermore, since a semicircular notch 36 is formed in the outer flange portion 35 of the mount bracket 3, a long welding length for fixing the outer flange portion 35 and the outer wall 24 of the side member 5 is ensured. I can do that. Furthermore, by extending the upper part of the outer flange part 35 on the rear side of the vehicle closer to the cylindrical part 40, the distance between the support part of the leaf spring 11 and the mount bracket 3 is shortened, and the side near the cylindrical part 40 is extended. The rigidity of the member 5 on the outer member 20 side can be improved.

The present invention is not limited to the embodiments described above.
For example, regarding the shape of the reinforcing portion 45, the vertical length, the length in the longitudinal direction of the vehicle, etc. may be changed as appropriate. Further, the second portion 45b may be made into a rectangular shape, or the first portion 45a and the second portion 45b may have the same vertical width, so that the reinforcing portion 45 as a whole may be made into a rectangular shape. Further, the support position of the cylindrical portion 40 may be placed in the first portion 45a or in a position spanning the first portion 45a and the second portion 45b, so that the cylindrical portion 40 is supported relative to the reinforcing portion 45. The support position may be changed as appropriate. Further, the second portion 45b may be configured to further extend in the opposite direction (vehicle rearward) from the first portion 45a.

Further, in the above embodiment, the second portion 45b of the reinforcing portion 45 and the cylindrical portion 40 are fixed by welding, but a structure may be adopted in which the second portion 45b and the cylindrical portion 40 are supported without being fixed. .
Further, for example, the reinforcing portion 45 may extend obliquely along the inner member 19 in the vehicle longitudinal direction and the vehicle vertical direction. However, it is desirable that the front end of the reinforcing portion 45 extends linearly in the longitudinal direction of the vehicle so that it can approach the cross member 10 at a short distance.

Further, in the embodiment described above, the present invention is adopted and the reinforcing portion 45 is provided between the cross member 10 at the rearmost portion of the vehicle and the rear support portion of the leaf spring 11. Alternatively, the present invention may be applied to a cross member 10 having a support portion for leaf springs 11 on the front side. For example, in the case where a support portion for the leaf spring 11 is provided on the front side of the cross member 10, the reinforcing portion 45 is arranged so as to extend toward the rear of the vehicle toward the cross member 10. Further, the present invention may be applied to the front support portion of the leaf spring 11.

Further, in the above embodiment, the reinforcing portion 45 is provided along the inner members 19 of the

side members

5 and 6, but a reinforcing portion similar to the reinforcing portion 45 may be further provided along the outer member 20.
Further, the detailed structures of the

side members

5, 6, cross member 10, cylindrical portion 40, etc. may be changed as appropriate.
The vehicle 1 may also not have a cargo box. The present invention can be widely applied to vehicles equipped with leaf springs as suspension devices.

1 Vehicle 3 Mount bracket 4

Packing box

5, 6 Side member 8 Suspension device 10 Cross member 11 Leaf spring 19a Front inner member 19b Rear inner member 40 Cylindrical part 41 Shackle pin (connection shaft)
45 Reinforcement part 45a First part 45b Second part 50 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;
leaf springs that are respectively arranged along the pair of side members and support an axle of the vehicle;
a connecting shaft rotatably connecting one end of the leaf spring to the side member;
The side member and the connection shaft are lower structures of a vehicle that are connected at a position spaced apart from a connection portion between the side member and the cross member in the longitudinal direction of the vehicle,
a cylindrical part that is fixed by penetrating a side surface of the side member in the vehicle width direction, and into which the connecting shaft is rotatably inserted into the side member;
a reinforcing portion provided on the side surface of the side member so as to surround the cylindrical portion on at least one end side of the cylindrical portion;
The reinforcing portion includes a first portion extending in a first direction toward the cross member, and a second portion provided continuously with the first portion and extending in a second direction opposite to the first direction. A vehicle lower structure characterized by having:
The vehicle lower structure according to claim 1, wherein the reinforcing portion holds the one end portion of the cylindrical portion.
The vehicle lower structure according to claim 1 or 2, wherein the reinforcing portion is provided at an inner end in the vehicle width direction of both ends of the cylindrical portion.
The vehicle lower structure according to any one of claims 1 to 3, wherein the second portion has a substantially annular shape surrounding the cylindrical portion.
The lower part of the vehicle according to any one of claims 1 to 3, wherein the first portion is arranged to extend linearly in the extending direction of the side member toward the cross member. structure.
The vehicle according to any one of claims 1 to 4, wherein the first portion and the second portion have a width larger in a direction perpendicular to the extending direction of the side member than the cylindrical portion. Undercarriage of.
The side member is formed of a member having a thinner plate thickness at a portion closer to the cylindrical portion than the connection position with the cross member in the extension direction than a portion on the opposite side to the cylindrical portion side. The vehicle lower structure according to any one of claims 1 to 6.
The cross member is disposed at the rearmost of the plurality of cross members of the vehicle connecting the pair of side members,
The lower structure of a vehicle according to any one of claims 1 to 7, wherein the cylindrical portion is arranged behind the cross member in the vehicle.
The side member is a hollow member, and has reinforcement therein that extends in the vehicle width direction and connects inner walls on both side surfaces in the vehicle width direction,
9. The vehicle lower structure according to claim 1, wherein the reinforcement is disposed at a longitudinal position of the vehicle between the reinforcing portion and the cross member.
The vehicle includes a mounting bracket for fixing a cargo box to the side member,
The vehicle lower structure according to any one of claims 1 to 9, wherein the mount bracket is disposed at a longitudinal position of the vehicle between the reinforcing portion and the cross member.