Vehicle undercarriage

Abstract

To increase a degree of freedom in arrangement of devices, etc. around a vehicle frame.SOLUTION: A sub-frame 14 integrated with a cell pack 16 is connected to a lower surface of the main frame 12 having a pair of left and right main side members 18L, 18R, and a plurality of main cross members 20 connected to the main side members 18L, 18R. Jack-up brackets 34, which form jack-up points, are connected to respective outer side-surfaces of the side members 18L, 18R in a vehicle widthwise direction. Interference between an arm 32 of a two-post lift used to load / unload a battery pack 16 and the sub-frame 14 is avoided.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a vehicle underbody structure, and particularly to the underbody structure of a vehicle having a separate structure.

Background Art

[0002] There is known a vehicle having a separate structure in which a body is mounted on a frame. Typically, a ladder frame is adopted as the frame. The ladder frame has a pair of left and right side members extending along the longitudinal direction of the vehicle, and a plurality of cross members connecting the left and right side members. Patent Document 1 below shows a frame (1) having a jack-up point set on the lower surface (see paragraph 0017, etc.). Note that the reference numerals in the above ( ) are the reference numerals used in Patent Document 1 below and are not related to the reference numerals used in the description of the embodiments of the present application.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, there has been an increasing demand for mounting devices around the frame, and it may occur that the devices or members for mounting the devices interfere with the jack-up points on the lower surface of the side members of the frame.

[0005] An object of the present invention is to increase the degree of freedom in mounting devices around the frame.

Means for Solving the Problems

[0007] The jack-up bracket allows for the creation of jack-up points other than on the underside of the side member.

[0008] The above vehicle understructure may further include a battery pack mounted between a pair of side members and a subframe fastened to the underside of the pair of side members to support the battery pack. The jack-up bracket is located within the range of the subframe in the longitudinal direction of the vehicle.

[0009] Even within the range of a subframe connected to the underside of a side member, a jack-up point can be formed while avoiding interference between the lift arm used to lift the vehicle and the subframe.

[0010] In the above vehicle understructure, the jack-up bracket is hollow square Column-shaped ru . The jack-up bracket has a side facing inward in the vehicle width direction, a side facing outward in the vehicle width direction, a side facing the front of the vehicle, and a side facing the rear of the vehicle. The column shape ensures sufficient strength to support the vehicle, and the hollow design allows the jack-up bracket to deform, absorbing collision loads from the side of the vehicle.

[0011] In the above vehicle understructure, the jack-up bracket is hollow square The front and rear sides of the column-shaped vehicle have a structure that is vulnerable to collision loads from the side of the vehicle. The front and rear sides of the vehicle have ridges that extend vertically, which constitute the aforementioned fragile structure. The weak structure of the front and rear sides of the vehicle makes the jack-up bracket itself more susceptible to deformation, which suppresses deformation of the side members and prevents the propagation of deformation to the battery pack. [Effects of the Invention]

[0012] By providing jack-up points on parts of the main frame other than the underside of the side members, the degree of freedom in arranging equipment around the main frame and the arrangement of components for mounting equipment can be increased. [Brief explanation of the drawing]

[0013] [Figure 1] This is an exploded perspective view of the vehicle understructure of this embodiment. [Figure 2] This diagram shows the exterior of a two-post lift. [Figure 3] This is a bottom view of the vehicle understructure of this embodiment. [Figure 4] This is an enlarged perspective view of the jack-up bracket and its surroundings. [Figure 5] This is a perspective view showing the jack-up bracket. [Figure 6] This is a perspective view showing another example of a jack-up bracket. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to the drawings. In the following description, unless otherwise specified, terms expressing relative positions and orientations such as front, rear, left, right, up, and down refer to relative positions and orientations with respect to the vehicle. In addition, in the left-right direction (width direction) of the vehicle, the side closer to the centerline extending in the front-rear direction of the vehicle is referred to as the inner side in the vehicle width direction, and the side further away is referred to as the outer side in the vehicle width direction. In each figure, the direction of arrow FR is forward, the direction of arrow UP is upward, the direction of arrow LH is left, and the direction of arrow OUT is outward in the vehicle width direction.

[0015] Figure 1 is an exploded perspective view showing the main parts of the vehicle understructure 10 of this embodiment. The vehicle understructure 10 is a separate structure understructure of the vehicle and includes a main frame 12, a subframe 14 which is connected to the lower surface of the central part of the main frame 12 in the longitudinal direction of the vehicle, and a battery pack 16 which is supported on the subframe 14.

[0016] The main frame 12 has a pair of main side members 18 that extend along the front-rear direction on the left and right sides of the vehicle, and a plurality of main cross members 20 that extend along the vehicle width direction and are coupled to the main side members 18 at both ends. When it is necessary to distinguish between the left and right main side members 18, the left main side member is described as the left main side member 18L, and the right main side member is described as the right main side member 18R.

[0017] A battery pack 16 is disposed in the space between the left main side member 18L and the right main side member 18R. To dispose the battery pack 16, no main cross member 20 is disposed in this space, and the main cross members 20 are disposed at the front and rear portions. The battery pack 16 is fixed onto the sub-frame 14 to be integrated, and is mounted on the main frame 12 by coupling the sub-frame 14 to the main frame 12.

[0018] The sub-frame 14 has a pair of sub-side members 22 extending along the left and right sides of the vehicle in the front-rear direction, and a plurality of sub-cross members 24 extending in the vehicle width direction and having both ends coupled to the left and right sub-side members 22 respectively. When it is necessary to distinguish between the left and right sub-side members 22, the left sub-side member is described as the left sub-side member 22L, and the right sub-side member is described as the right sub-side member 22R. When the sub-frame 14 is coupled to the main frame 12, at least a part of the left sub-side member 22L is located directly below the left main side member 18L, and at least a part of the right sub-side member 22R is located directly below the right main side member 18R. More specifically, the front portions of the left and right sub-side members 22L, 22R are located directly below the left and right main side members 18L, 18R, and the rear portions are located inside the vehicle width direction from the left and right main side members 18L, 18R. The sub-frame 14 and the main frame 12 are fastened at the portions where the left and right sub-side members 22L, 22R and the left and right main side members 18L, 18R are vertically overlapped. By coupling the sub-frame 14 to the main frame 12, a ladder-shaped frame is formed as a whole.

[0019] Shock-absorbing members 26 are coupled to both side surfaces of the sub-frame 14, that is, the outer side surfaces in the vehicle width direction of the left and right sub-side members 22L, 22R respectively. In particular, the shock-absorbing members 26 may be coupled to the outer side surfaces in the vehicle width direction of the portions of the left and right sub-side members 22L, 22R that are located directly below the main side members 18L, 18R. The shock-absorbing member 26 has a shape in which a cross-section orthogonal to the front-rear direction has a rectangular frame and partitions that divide the inside of this frame into several parts in the vehicle width direction (see FIG. 4). This cross-sectional shape is constant in the front-rear direction. The shock-absorbing member 26 can be composed of an aluminum extrusion. During a side collision of the vehicle, the shock-absorbing member 26 is crushed, and the energy of the collision is absorbed by the deformation at this time.

[0020] The battery pack 16 supplies power to the electric motor that drives the vehicle and stores the power regenerated by this electric motor.

[0021] The battery pack 16 is attached to and detached from the main frame 12 in an integrated state, coupled to the subframe 14. When loading or unloading the battery pack 16 from the vehicle, for example, a two-post lift 28, illustrated in Figure 2, is used to support the vehicle's jack-up points and lift the vehicle. This ensures space below the main frame 12 for the battery pack 16 before installation and after removal, as well as space for workers. The two-post lift 28 has a pair of columns 30 positioned on both the left and right sides of the vehicle, and two arms 32 provided on each of the pair of columns 30. The tips of the four arms 32 support the vehicle's jack-up points from below, and the four arms 32 are raised to lift the vehicle.

[0022] In order to load and unload the battery pack 16, the subframe 14 must be attached to and detached from the main frame 12. For this reason, the jack-up points cannot be provided on the subframe 14. Furthermore, the jack-up points must be located in a position where the arms 32 of the two-post lift do not interfere with the subframe 14, the battery pack 16 integrated with it, and the shock-absorbing members 26, etc. However, if the jack-up points are located in front of or behind the subframe 14, the arms 32 of the existing two-post lift 28 may not be able to reach the jack-up points. Also, if the subframe 14 is positioned further inward in the vehicle width direction in order to use the existing two-post lift 28, the battery pack 16 may have to be made smaller. In this vehicle understructure 10, within the range A (see Figure 3) where the subframe 14 exists in the front-rear direction, a jack-up bracket 34 that defines the jack-up points is attached to the outer side surface in the vehicle width direction of the main side member 18.

[0023] Figure 3 shows the vehicle understructure 10 viewed from below, with the arms 32 of the two-post lift indicated by dashed lines. Figure 4 is a magnified view of the area around the right-side jack-up bracket 34. Figure 5 shows the jack-up bracket 34 by itself. The structure of the left-side jack-up bracket 34 and its surroundings are symmetrical to that in Figures 4 and 5.

[0024] The jack-up bracket 34 has a vertically elongated, hollow column shape, particularly a roughly rectangular column shape, and includes an outer member 36 and an inner member 38 that form the sides of the column shape, and a bottom member 40 that forms the bottom surface. The outer member 36 and the inner member 38 have a roughly U-shaped cross-section, with the outer member 36 located on the outside in the vehicle width direction and the inner member 38 located on the inside in the vehicle width direction. The U-shaped ends of the outer member 36 and the inner member 38 are joined together by welding or other methods to form a hollow rectangular column shape. The jack-up bracket 34 may be connected to the main side member 18 by fastening components such as bolts and nuts. Alternatively, it may be connected by welding or other methods. The bottom member 40 is connected to the lower ends of the outer member 36 and the inner member 38 by welding or other methods, forming the rear jack-up points on the left and right sides, respectively. This jack-up point is offset outward in the vehicle width direction from the lower surface of the main side member 18. This position prevents interference between the arm 32 of the two-post lift that supports the vehicle at the jack-up point and the detachable subframe 14, etc. Lightweight holes 42 are formed on the side 34a of the jack-up bracket 34 that faces outward in the vehicle width direction. In the illustrated example, there are two weight-reducing holes 42, but there may be one, three or more, or none at all.

[0025] The jack-up bracket 34 is long in the vertical direction, providing sufficient strength to support the load at the jack-up point. Furthermore, its hollow shape allows it to deform and absorb impact energy when struck by an object from the side. This suppresses deformation of the main side member 18, preventing deformation from affecting the battery pack 16 located on the inside of the main side member 18 in the vehicle width direction.

[0026] Figure 6 shows another example of a jack-up bracket. The jack-up bracket 50 has a similar external shape and general structure to the jack-up bracket 34 shown in Figure 5, and has a rectangular prism-shaped side formed by an outer member 52 and an inner member 54 having a roughly U-shaped cross-section, and also has a bottom member 56. The difference from the jack-up bracket 34 shown in Figure 5 is that holes 58 are formed on the front side 50b and rear side 50c of the vehicle to make those sides vulnerable. The parts of the jack-up bracket 50 around the holes 58 have a vulnerable structure. In the illustrated example, three holes 58 are provided on each of the two sides 50b and 50c. The number of holes 58 is not limited to three. Also, the shape of the holes may be circular as shown, or it may be an elongated shape or other shape. By providing the holes 58, the jack-up bracket 50 becomes more easily deformed during a side collision, the deformation of the main side member 18 is suppressed, and the propagation of deformation to the battery pack 16 is suppressed.

[0027] Another example, the jack-up bracket 60 shown in Figure 6, has a similar external shape and general structure to the jack-up bracket 34 shown in Figure 5. It has an outer member 62 and an inner member 64 with a roughly U-shaped cross-section, forming the sides of a rectangular prism, and also has a bottom member 66. The difference from the jack-up bracket 34 shown in Figure 5 is that ridges 68 are formed on the front side 60b and rear side 60c of the vehicle to make those sides vulnerable. The ridges 68 are vulnerable structures provided on the front and rear sides 60b and 60c of the jack-up bracket 60. The ridges 68 extend roughly in the vertical direction, and the sides 60b and 60c on which the ridges 68 are provided are curved in the horizontal cross-section at the portion of the ridges 68. In the event of a side collision, the curved portion formed by the ridges 68 becomes the starting point of deformation, making the jack-up bracket 60 more susceptible to deformation. This suppresses the deformation of the main side member 18 and suppresses the propagation of deformation to the battery pack 16.

[0028] An example has been described in which the rear jack-up point is formed using jack-up brackets 34, 50, and 60. However, depending on the relationship with the battery pack and subframe, the front jack-up point may be formed instead of the rear jack-up point using a jack-up bracket connected to the outside of the main side member. Alternatively, both the front and rear jack-up points may be formed using jack-up brackets connected to the outside of the main side member. [Explanation of symbols]

[0029] 10 Vehicle understructure, 12 Main frame, 14 Subframe, 16 Battery pack, 18 Main side member, 20 Main cross member, 22 Subside member 24 Subcross member, 26 Shock absorbing member, 28 Two-post lift, 32 Arm, 34, 50, 60 Jack-up bracket, 36, 52, 62 Outer member, 38, 54, 64 Inner member, 40, 56, 66 Bottom member, 58 Hole, 68 Raised.

Claims

1. A main frame having a pair of side members extending along the front-rear direction of the vehicle on the left and right sides of the vehicle, and a plurality of cross members extending along the width direction of the vehicle and connecting to each of the pair of side members, A jack-up bracket is connected to the outer side surface in the vehicle width direction of each of the pair of side members, forming a jack-up point. Includes, The jack-up bracket has a vertically elongated, hollow rectangular prism shape, and has a side facing inward in the vehicle width direction opposite to the side member, a side facing outward in the vehicle width direction, a side facing the front of the vehicle, and a side facing the rear of the vehicle. On the front and rear sides of the vehicle, there are protrusions that extend in the vertical direction. Vehicle understructure.

2. The vehicle understructure according to claim 1, A battery pack mounted between the pair of side members, A subframe fastened to the lower surface of the pair of side members and supporting the battery pack, Includes, The jack-up bracket is located within the range of the subframe in the longitudinal direction of the vehicle. Vehicle understructure.

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