Vehicle Structure

The closed cross-section structure with an opening in the cross member and internal reinforcements addresses load distribution issues in leaf spring suspension systems, enhancing structural integrity and assembly efficiency.

JP7616481B2Active Publication Date: 2025-01-17MITSUBISHI MOTORS CORP
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Patent Information

Application Number
JP2024512247
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2022-03-29
Filing Date
2023-03-23
Publication Date
2025-01-17
Estimated Expiration
2043-03-23

AI Technical Summary

Technical Problem

In leaf spring type suspension systems, the load applied via the shackle is not effectively distributed between the side frame and the cross member, leading to potential structural weaknesses and complexity in assembly.

Method used

A closed cross-section structure for side frames with an opening in the lower wall of the cross member, allowing the shackle to be pivotally attached, and reinforced by internal reinforcements, ensuring load distribution between the side frame and cross member.

Benefits of technology

Enhances load distribution and structural integrity by allowing the shackle to be securely attached within the cross member, improving assembly efficiency and reducing complexity while maintaining rigidity and weight efficiency.

✦ Generated by Eureka AI based on patent content.

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Patent Text Reader

Abstract

In the present invention, an opening (36) is provided to an under surface (1208) of a rear cross member (14B), and a pair of shackles (24) are provided to a portion inside the profile of the rear cross member (14B), when viewed from the vehicle width direction, so as to sandwich an outer lateral surface (1202) and an inner lateral surface (1204) via the opening (36). This configuration provides an advantage in achieving improvement in the durability of a side frame (12) because the shackles (24) can be provided to a portion of the side frame (12) where the rear cross member (14B) is joined, and a load exerted from a leaf spring (38) via the shackles (24) can be received by both the side frame (12) and the rear cross member (14B).
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Description

[Technical field]

[0001] The present invention relates to a vehicle structure. [Background technology]

[0002] 2. Description of the Related Art A leaf spring suspension system is known as a vehicle suspension system, in which an end of a leaf spring that suspends an axle is swingably supported on a side frame via a shackle (see Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2014-61724 [Patent Document 2] Japanese Patent Application Publication No. 2020-132101 Summary of the Invention [Problem to be solved by the invention]

[0004] In such a leaf spring suspension device, it is conceivable to provide a shackle at the connecting portion where the cross member of the side frame is connected so that the load applied through the shackle is also borne by the side frame and the cross member. The present invention has been made in consideration of the above circumstances, and has an object to provide a vehicle structure in which the load applied through the shackle can also be supported by the side frames and cross members. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, one embodiment of the present invention comprises a pair of side frames of a closed cross-sectional structure arranged at intervals in the vehicle width direction and extending in the fore-and-aft direction of the vehicle, a cross member of a closed cross-sectional structure extending in the vehicle width direction and connecting the pair of side frames, and a leaf spring that is swingably supported on the side frames via a shackle, wherein the cross member has an opening in a lower wall at an end in the vehicle width direction, and the shackle is swingably attached to the side frame by being inserted into the opening at a location in the side frame between the front wall and rear wall of the cross member. Effect of the Invention

[0006] According to one embodiment of the present invention, a shackle can be provided at the location of the side frame where the cross member is connected, so that the load applied from the leaf spring through the shackle can be supported by the side frame and the cross member. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view of a pair of side members and a cross member that constitute a ladder frame to which a leaf spring suspension device according to an embodiment is applied, as viewed from the front of a vehicle. [Diagram 2] 1 is a perspective view showing a main part of a leaf spring suspension device according to an embodiment as viewed from the inside in a vehicle width direction. [Diagram 3] 4 is a perspective view of a connecting portion between a side frame and a cross member as viewed from the outside in the vehicle width direction. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A leaf spring suspension device according to an embodiment of the present invention will now be described with reference to the drawings. In the following drawings, the symbol FR indicates the front of the vehicle, the symbol UP indicates the upper side of the vehicle, the symbol IN indicates the inside in the vehicle width direction, and the symbol OUT indicates the outside in the vehicle width direction. The vehicle to which the leaf spring suspension system of this embodiment is applied is a pickup truck. A pickup truck is a frame vehicle in which a cabin and a cargo box that constitute the body are mounted on a ladder frame. As shown in FIG. 1, the ladder frame 10 includes a pair of side frames 12 that extend in the fore-and-aft direction of the vehicle on both sides in the vehicle width direction, and a plurality of cross members 14A, 14B that connect the pair of side frames 12 at intervals in the fore-and-aft direction of the vehicle.

[0009] The pair of side frames 12 are hollow and have a vertically elongated rectangular cross section, and are formed with a closed cross-sectional structure. The pair of side frames 12 have an outer surface 1202 on the outer side in the vehicle width direction, an inner surface 1204 on the inner side in the vehicle width direction, an upper surface 1206 that connects the outer surface 1202 and the inner surface 1204 and faces upward, and a lower surface 1208 that faces downward.

[0010] As shown in FIG. 1, the multiple cross members 14A, 14B extend between the opposing inner surfaces 1204 of the pair of side frames 12 in the vehicle width direction. Of the multiple cross members 14A, 14B, the rear cross member 14B located at the rearmost position of the vehicle also serves as a member for supporting a spare tire (not shown) below this rear cross member 14B. In the present embodiment, the rear cross member 14B includes an upper member 16 that constitutes the upper portion of the rear cross member 14B, and a lower member 18 that constitutes the lower portion of the rear cross member 14B. The upper member 16 is composed of a central member 20 and a pair of end members 22 connected to both ends of the central member 20 in the vehicle width direction. As shown in FIG. 2, the central member 20 and the pair of end members 22 have a central front wall 2002 and an end front wall 2202 facing toward the front of the vehicle, a central rear wall 2004 and an end rear wall 2204 facing toward the rear of the vehicle, and a central upper wall 2006 and an end upper wall 2206 connecting them and facing upward, and are formed to be open downward. The lower member 18 has a front wall 1802 facing toward the front of the vehicle, a rear wall 1804 facing toward the rear of the vehicle, and a lower wall 1806 that connects the front wall 1802 and the rear wall 1804 and faces downward, and is formed in an upwardly open shape. As shown in FIG. 2, both ends of the upper member 16 in the vehicle width direction, in this embodiment both ends of the end member 22 in the vehicle width direction, and both ends of the lower member 18 in the vehicle width direction are formed as inclined portions 1808 that incline upward as they move inward in the vehicle width direction.

[0011] As shown in FIGS. 1 and 2, the inner end of the end member 22 in the vehicle width direction is placed over the outer end of the central member 20 in the vehicle width direction and joined to the central member 20. That is, the end front wall 2202 of the end member 22 is joined to the central front wall 2002 of the central member 20, the end rear wall 2204 is joined to the central rear wall 2004, and the end top wall 2206 is joined to the central top wall 2006. In addition, the upper end portion of the front wall 1802 of the lower member 18 is overlapped and joined to the inside of the lower end portion of the central front wall 2002 of the central member 20 and the lower end portion of the end front wall 2202 of the end member 22, and the upper end portion of the rear wall 1804 is overlapped and joined to the inside of the lower end portion of the central rear wall 2004 and the lower end portion of the end rear wall 2204. Flanges 2210 provided on the vehicle width direction outer ends of the end front wall 2202, the central rear wall 2204 and the end rear wall 2204 of the end member 22 are joined to the inner surface 1204 and the upper surface 1206 of the side frame 12. Additionally, flanges 1810 provided on the vehicle widthwise outer ends of the front wall 1802, rear wall 1804 and bottom wall 1806 of the lower member 18 are joined to the inner surface 1204 and bottom surface 1208 of the side frame 12.

[0012] 1 and 3, the tubular portion 30 supporting the upper shackle pin 26 (see FIG. 2) of the shackle 24 is provided within the front-to-rear width of the rear cross member 14B when viewed from the vehicle width direction. In detail, the tubular portion 30 is provided across the inner surface 1204 and the outer surface 1202 of the side frame 12 between the front wall (end front wall 2202 and front wall 1802) of the rear cross member 14B and the rear wall (end rear wall 2204 and rear wall 1804) of the rear cross member 14B when viewed from the vehicle width direction. As shown in FIG. 3, a pair of reinforcements 32 joined to the inner surface 1204, the outer surface 1202, the upper surface 1206, and the lower surface 1208 of the side frame 12 are provided at the front and rear of the tubular portion 30. The reinforcements 32 are provided inside the side frames 12 so as to sandwich the support shaft (upper shackle pin 26) of the shackle 24 from the vehicle front-rear direction. The pair of reinforcements 32 are also arranged so as to be located within the front-rear width of the rear cross member 14B. In this embodiment, the pair of reinforcements 32 are located on extensions of the front and rear walls of the rear cross member 14B in the vehicle width direction. 1 and 3, reference numeral 34 denotes a support bracket that supports the body (cabin or cargo box). The support bracket 34 is joined to each of the outer surfaces 1202 of the pair of side frames 12. At least a portion of the support bracket 34 overlaps with the rear cross member 14B when viewed from the vehicle width direction, as shown in FIG.

[0013] As shown in FIG. 2, the lower wall 1806 at the end of the lower member 18 in the vehicle width direction is provided with an opening 36 that allows the shackle 24, which will be described later, to be attached and that allows the shackle 24 to swing. The opening 36 has an outer edge 3602 extending in the fore-and-aft direction of the vehicle along the lower end of the inner surface 1204 of the side frame 12, a leading edge 3604 and a trailing edge 3606 extending in a straight line from both ends of the outer edge 3602 toward the inside in the vehicle width direction, and an inner edge 3608 connecting the inner ends of the leading edge 3604 and the trailing edge 3606 in the vehicle width direction. In this embodiment, the outer edge 3602 is located outside the lower end of the inner surface 1204 in the vehicle width direction, and the lower surface 1208 of the side frame 12 is exposed inside the outer edge 3602 in the vehicle width direction. Therefore, when performing the work of attaching the shackle 24 through the opening 36, the hand is unlikely to touch the outer edge 3602, so that the sense of danger is suppressed and the workability is improved. A flange 3610 is provided extending upward from each of the leading edge 3604, the trailing edge 3606, and the inner edge 3608. The flange 3610 extends over the entire length of the leading edge 3604, the trailing edge 3606, and the inner edge 3608, and reinforces the periphery of the opening 36 of the rear cross member 14B. 2, the leading edge 3604 and the trailing edge 3606 extend to the inside in the vehicle width direction from the joints between the central member 20 and the end members 22. Flanges 3610 provided on the leading edge 3604 and the trailing edge 3606 extend in the vehicle width direction across the joints between the central member 20 and the pair of end members 22.

[0014] In this embodiment, the opening 36 is not open on the outer side in the vehicle width direction, and a flange 1810 joined to the lower surface 1208 of the side frame 12 is located on the outer side in the vehicle width direction of the opening 36. Since the opening 36 is closed, the rigidity or strength of the area around the opening 36 of the rear cross member 14B is higher than when the opening 36 is open on the outer side in the vehicle width direction.

[0015] As shown in FIG. 2, the leaf spring suspension device 40 includes a leaf spring 38, a support shaft (not shown) that supports the front end of the leaf spring 38 so that it can swing relative to the side frame 12, and a shackle 24 that supports the rear end of the leaf spring 38 so that it can swing relative to the side frame 12. The shackle 24 is provided so as to sandwich an outer surface 1202 and an inner surface 1204 of the side frame 12. The upper end of the shackle 24 is connected to the side frame 12 via an upper shackle pin 26, and the lower end of the shackle 24 is connected to the vehicle rear end of the leaf spring 38 via a lower shackle pin 28. Therefore, the attachment point (upper part in this embodiment) of the shackle 24 to the side frame 12 is located inside the width of the rear cross member 14B in the vehicle front-rear direction.

[0016] Next, the effects of this embodiment will be described. According to this embodiment, an opening 36 is provided on the underside of the rear cross member 14B, and the shackle 24 is attached to the side frame 12 through the opening 36 on the inside of the width of the rear cross member 14B in the vehicle front-rear direction. Therefore, a shackle 24 can be provided at the point where the side frame 12 is connected to the rear cross member 14B, and the load applied from the leaf spring 38 through the shackle 24 can be supported by the side frame 12 and the rear cross member 14B. In addition, the structure for providing the shackle 24 at the location where the rear cross member 14B of the side frame 12 is joined is a simple structure in which an opening 36 is provided on the underside of the rear cross member 14B. This prevents the structure from becoming complicated, and also prevents the assembly work for the rear cross member 14B and the shackle 24 from becoming complicated.

[0017] In the present embodiment, a pair of reinforcements 32 are provided inside the side frame 12 so as to sandwich the support shaft of the shackle 24 from the front-rear direction of the vehicle. Therefore, the pair of reinforcements 32 can efficiently reinforce the portion of the side frame 12 where the shackle 24 is provided.

[0018] In addition, in this embodiment, the rear cross member 14B has a closed cross-sectional structure having a front surface located at the front of the vehicle and a rear surface located at the rear of the vehicle, and a pair of reinforcements 32 are located on extensions of the front and rear surfaces of the rear cross member 14B. Therefore, it is more advantageous in reinforcing the portion where the rear cross member 14B of the side frame 12 is joined and in reinforcing the portion where the shackle 24 is provided.

[0019] In addition, in this embodiment, a support bracket 34 that supports the body is joined to the outer surfaces 1202 of a pair of side frames 12, and at least a portion of the support bracket 34 overlaps with the rear cross member 14B when viewed from the vehicle width direction. Therefore, the existing support bracket 34 can be used to reinforce the portion of the side frame 12 where the rear cross member 14B is joined.

[0020] In this embodiment, a flange 3610 is formed that is bent upward along the edge of the opening 36 of the rear cross member 14B. This is advantageous in ensuring the strength or rigidity of the rear cross member 14B despite the provision of the opening 36. Furthermore, when attaching the shackle 24 to the side frame 12 through the opening 36, the risk of injury from the edge of the opening 36 is eliminated, which is advantageous in improving workability.

[0021] In this embodiment, the rear cross member 14B is divided into a central member 20, a pair of end members 22, and a lower member 18 in order to reduce the weight of the rear cross member 14B while ensuring the rigidity and strength of the rear cross member 14B. The pair of end members 22 are formed of plate-like members having a thickness D1 greater than the central member 20 and the lower member 18, and their outer ends in the vehicle width direction are connected to the side frames 12. The lower member 18 is formed of a plate-like member having a thickness D2 that is thicker than the central member 20 and smaller than the end members 22, and its outer end in the vehicle width direction is joined to the side frame 12. In this embodiment, a spare tire is provided below the lower member 18. The central member 20 is formed of a plate-like member having a thickness D3 smaller than the lower member 18 and the end members 22, and its outer ends in the vehicle width direction are joined to the pair of end members 22. The end members 22 are made of thick plates because they are connected to the side frames 12. In particular, because the end members 22 are located only at the ends of the rear cross members 14B, weight increase is suppressed even if they are made of thick plates. The lower member 18 is made of a slightly thicker plate because it is connected to the side frames 12 and comes into contact with the spare tire. The central member 20 is made of a thinner plate to reduce weight.

[0022] In this embodiment, the flange 3610 extends across the joints between the central member 20 and the pair of end members 22 . Therefore, the flanges 3610 are advantageous in reinforcing the joints between the pair of end members 22 and the central member 20 .

[0023] In the present embodiment, the lower surface 1208 at each end of the rear cross member 14B is provided with an opening 36 at an inclined portion 1808 that inclines upward toward the inside in the vehicle width direction. Therefore, when viewed from the vehicle width direction, the opening 36 also has a shape that extends in the vertical direction. This is advantageous in terms of improving the workability when attaching the shackle 24 to the inner surface 1204 of the side frame 12 through the opening 36. Furthermore, by providing the inclined portions 1808 on the underside 1208 at both ends in the extension direction of the rear cross member 14B, the underside 1208 of the central portion in the extension direction of the rear cross member 14B is positioned higher. Therefore, attaching a spare tire to the underside 1208 of the central portion in the extension direction of the rear cross member 14B is advantageous in terms of ensuring a large distance between the spare tire and the ground.

[0024] Although various embodiments have been described above, it goes without saying that the present invention is not limited to such examples. It is clear that a person skilled in the art can come up with various modified or revised examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present invention. Furthermore, the components in the above-mentioned embodiments may be arbitrarily combined within the scope of the invention.

[0025] This application is based on a Japanese patent application (Patent Application No. 2022-53220) filed on March 29, 2022, the contents of which are incorporated by reference into this application. [Explanation of symbols]

[0026] 10 Ladder Frame 12 Side frame 1202 External surface 1204 Inner surface 1206 Top surface 1208 Bottom surface 14 Cross member 14B Rear cross member 16 Upper member 18 Lower member 1802 Front wall 1804 Back wall 1806 Lower wall 1808 Slope 1810 flange 1812 Band-shaped part 20 Central member 2002 Center front wall 2004 Center back wall 2006 Upper center wall 22 End member 2202 Front end wall 2204 End rear wall 2206 End top wall 2210 Flange 24 Shackle 26 Upper shackle pin 28 Lower shackle pin 30 Cylinder part 32 Reinforcement 34 Support bracket 36 Opening 3602 Outer edge 3604 Leading edge 3606 Trailing edge 3608 Common-law marriage 3610 Flange 38 Leaf spring 40 Leaf spring suspension

Claims

1. A pair of side frames having a closed cross-sectional structure arranged at an interval in a vehicle width direction and extending in a vehicle front-rear direction; A cross member having a closed cross section structure extending in a vehicle width direction and connecting the pair of side frames; a leaf spring that is swingably supported on the side frame via a shackle, The cross member has an opening in a lower wall at an end in a vehicle width direction, The shackle is pivotally attached to the side frame by being inserted through the opening at a location between the front wall and the rear wall of the cross member in the side frame. A vehicle structure characterized by:

2. A pair of reinforcements extending in a vehicle width direction and a vehicle up-down direction are provided inside the side frame, The pair of reinforcements are located between the front wall and the rear wall of the cross member in the side frame so as to sandwich the attachment point of the shackle to the side frame in the vehicle front-rear direction.

2. The vehicle structure according to claim 1.

3. The pair of reinforcements are respectively located on extensions of the front wall and the rear wall of the cross member in the vehicle width direction.

3. The vehicle structure according to claim 2.

4. A support bracket for supporting a body is provided and joined to an outer surface of the pair of side frames, When viewed from the vehicle width direction, at least a portion of the support bracket is located between the front wall and the rear wall of the cross member.

3. A vehicle structure according to claim 1 or 2.

5. An upwardly bent flange is formed along the edge of the opening.

3. A vehicle structure according to claim 1 or 2.

6. The cross member is composed of an upper member that is open downward and that constitutes an upper portion of the cross member, and a lower member that is open upward and that constitutes a lower portion of the cross member, The upper member is composed of a central member located at a center portion in a vehicle width direction and a pair of end members located at both ends in the vehicle width direction, The opening is provided in the lower member, The flange extends in the vehicle width direction across the joint between the central member and the end member.

6. The vehicle structure according to claim 5.

7. The lower surfaces of both ends of the cross member have inclined portions that incline upwardly toward the inside in the vehicle width direction, The opening is provided in the inclined portion.

3. A vehicle structure according to claim 1 or 2.

Citation Information

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