Vehicle frame structure

Abstract

A vehicle frame structure is obtained that is formed by die casting and has vehicle frame members that ensure the required rigidity and can be fastened with bolts. [Solution] The draft angle α of the mounting portion 30 provided on the inner surface 40B side of the vertical wall portion 40 of the cast body 28 is smaller than the draft angle α' of the general portion 44. In addition, the outer surface 40A side of the vertical wall portion 40 is formed to be substantially parallel to the inner surface 40B of the vertical wall portion 40. As a result, it is possible to reduce the entry angle (α) of the fastening tool used to fasten the bolts with respect to the reference line P along the vehicle width direction. As a result, it is possible to avoid interference between the fastening tool and the rib 42, and it is not necessary to cut a part of the rib 42 to avoid interference between the fastening tool and the rib 42. This makes it possible to ensure the rigidity required for the front part 12 of the vehicle, and to fasten the motor unit 13 to the mounting portion 36 with bolts.

Description

Technical Field

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

Background Art

[0002] Patent Document 1 below discloses a technique for bolting an engine to an engine mount bracket integrally formed with a chain case manufactured by aluminum die casting. In this prior art, it is possible to reduce the manufacturing cost and weight by integrally forming the chain case and the engine mount bracket.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Generally, when manufacturing a vehicle skeletal member by die casting, ribs or the like that stand along the mold extraction direction are formed on the vehicle skeletal member in order to increase the rigidity of the vehicle skeletal member. In addition, the vehicle skeletal member is provided with a draft gradient for releasing it from the mold.

[0005] Here, when providing a fastening surface for fastening a bolt to the vehicle skeletal member along the draft gradient, considering the insertion of a fastening tool for fastening the bolt, it is necessary to reduce the height of the rib in order to avoid interference with the rib. Accordingly, there is a possibility that the rigidity of the vehicle skeletal member decreases.

[0006] In consideration of the above facts, an object of the present invention is to obtain a vehicle skeletal structure including a vehicle skeletal member formed by die casting and having necessary rigidity and enabling bolt fastening.

Means for Solving the Problems

[0007] The vehicle frame structure according to the first embodiment comprises a die-cast vehicle frame member provided on the outside in the vehicle width direction of a motor unit that is located at the front or rear of the vehicle and drives the wheels, extending in the vehicle longitudinal direction, the vehicle frame member comprising a vertical wall portion formed on the motor unit side and extending in the vehicle longitudinal and vehicle vertical directions, a plurality of ribs erected from the vertical wall portion toward the outside in the vehicle width direction, and through holes formed in the region of the vertical wall portion surrounded by the ribs through which fastening members for fastening the motor unit are inserted, the direction of release from the mold for molding the vehicle frame member is in the vehicle vertical direction, and on the inner surface side constituting the inside in the vehicle width direction of the vertical wall portion, the draft angle of the peripheral portion of the through hole is smaller than the draft angle of the general portion excluding the peripheral portion of the through hole.

[0008] The vehicle frame structure according to the first embodiment includes a vehicle frame member provided on the outside in the vehicle width direction of a motor unit that is located at the front or rear of the vehicle and drives the wheels. This vehicle frame member extends in the longitudinal direction of the vehicle and is formed by die casting.

[0009] The vehicle frame member comprises a vertical wall, multiple ribs, and through holes. The vertical wall is formed on the motor unit side of the vehicle frame member and extends in the longitudinal and vertical directions of the vehicle. The multiple ribs are erected from the vertical wall outward in the vehicle width direction. Furthermore, the through holes are provided in the vertical wall and formed within the area surrounded by the ribs.

[0010] In this way, by providing multiple ribs around the through-hole, it is possible to improve the rigidity of the vertical wall portion. Furthermore, a fastening member is inserted through this through-hole, and the motor unit is fastened to the vehicle frame member via the fastening member and the vertical wall portion.

[0011] In this embodiment, the vehicle frame member is formed by die casting. On the inner surface that constitutes the inner side in the vehicle width direction of the vertical wall portion, the direction of release from the mold for forming the vehicle frame member is the vehicle vertical direction, and the draft angle of the area around the through hole is smaller than the draft angle of the general area excluding the area around the through hole.

[0012] Considering the fastening strength provided by the fastening member, the outer surface is formed to be approximately parallel to the inner surface of the vertical wall, in accordance with the draft angle of the inner surface of the vertical wall. In this embodiment, since the draft angle of the area around the through hole on the inner surface of the vertical wall is smaller than that of the general section (comparative example), it is possible to reduce the entry angle of the fastening tool, such as an impact wrench, used when fastening the fastening member to a reference line along the vehicle width direction, compared to the comparative example.

[0013] As a result, in this embodiment, interference between the fastening tool and the rib can be avoided, eliminating the need to reduce the height of the rib or cut a portion of the rib to avoid interference between the tool and the rib. In this way, since there is no need to cut the rib, it is possible to ensure the rigidity required for a vehicle frame member formed by die casting.

[0014] The vehicle frame structure according to the second embodiment is a vehicle frame structure according to the first embodiment in which, in the area surrounding the through hole, the outer surface that constitutes the outer side in the vehicle width direction of the vertical wall portion has an angle substantially the same as the draft angle formed on the inner surface.

[0015] The vehicle frame member has vertical walls that extend in the longitudinal and vertical directions of the vehicle, and multiple ribs that are erected from these vertical walls outward in the vehicle width direction. Since the direction of release from the mold for the vehicle frame member is in the vehicle vertical direction, the outer surface of the vertical wall is formed by a sliding mold that moves outward in the vehicle width direction. For this reason, there is no need to provide a draft angle on the outer surface of the vertical wall.

[0016] In the vehicle skeletal structure according to the second aspect, the outer surface side that constitutes the outside in the vehicle width direction of the vertical wall portion is formed at substantially the same angle as the draw gradient formed on the inner surface side of the vertical wall portion, so that the axial force of the fastening member can be made substantially orthogonal to the fastening surface of the fastening member, and the fastening strength can be improved.

[0017] The vehicle skeletal structure according to the third aspect is the vehicle skeletal structure according to the first aspect or the second aspect, in which some of the plurality of ribs are provided at the peripheral portion of the through hole.

[0018] In the vehicle skeletal structure according to the third aspect, some of the plurality of ribs are provided at the peripheral portion of the through hole, so that the rigidity can be improved at the peripheral portion of the through hole.

Advantages of the Invention

[0019] As described above, the vehicle skeletal structure according to the present invention is formed by die casting and has an excellent effect that the required rigidity is ensured and bolt fastening can be performed.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view of a vehicle to which the vehicle skeletal structure according to the present embodiment is applied, as viewed from the upper left front side of the vehicle. [Figure 2] It is an exploded perspective view of a vehicle to which the vehicle skeletal structure according to the present embodiment is applied, as viewed from the upper left front side of the vehicle. [Figure 3] It is a partial enlarged perspective view showing an enlarged main part in FIG. 2. [Figure 4] It is a side view of a vehicle to which the vehicle skeletal structure according to the present embodiment is applied. [Figure 5] It is a schematic cross-sectional view when cut along the line A-A shown in FIG. 4. [Figure 6] It is a partial enlarged cross-sectional view showing an enlarged part when cut along the line B-B shown in FIG. 2.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, with reference to the drawings, the vehicle skeleton structure according to an embodiment of the present invention will be described. In each figure, the arrow FR appropriately shown indicates the front side in the vehicle front-rear direction, and the arrow UP indicates the upper side in the vehicle up-down direction. The arrow RH indicates the right side in the vehicle width direction, and the arrow LH indicates the left side in the vehicle width direction. Hereinafter, when simply describing the directions of front and rear, up and down, and left and right, unless otherwise specified, it shall indicate the front and rear in the vehicle front-rear direction, the up and down in the vehicle up-down direction, and the left and right in the vehicle left-right direction (vehicle width direction).

[0022] <Configuration of the vehicle skeleton structure> First, the configuration of the vehicle skeleton structure according to the present embodiment will be described.

[0023] In FIGS. 1 and 2, the front part (vehicle front part) 12 of a vehicle 10 to which the vehicle skeleton structure according to the present embodiment is applied is shown. This vehicle 10 is an electric vehicle, a fuel cell vehicle, or the like that runs on power generated by a motor unit 13. As shown in FIGS. 1 and 2, in the vehicle front part 12, wheel houses 14 in which front wheels (not shown) are arranged on the left and right extend in the vehicle front-rear direction, and the right wheel house 14 and the left wheel house 14 are connected by a cross member 16 extending in the vehicle width direction.

[0024] Also, inside the wheel houses 14 in the vehicle width direction, suspension towers 18 that support the upper ends of the front wheel suspensions are respectively provided, and below the suspension towers 18, front side members 20 extending in the vehicle up-down direction and the vehicle front-rear direction are provided. And behind the wheel houses 14, front pillars 22 extending in the vehicle up-down direction and the vehicle front-rear direction are provided.

[0025] In this embodiment, for example, a pair of left and right wheelhouses 14 including a suspension tower 18 and a front side member 20, a cross member 16, and a front pillar 22 are integrally molded by die casting using an aluminum alloy, magnesium alloy, or the like (cast body 28). In this embodiment, the cast body 28 has a roughly U-shape with the front side of the vehicle open in a plan view.

[0026] In this embodiment, mounting portions (periphery of the through-hole) 30 are provided at the points where the left and right wheelhouses 14 and the cross member 16 are connected. An enlarged view of these mounting portions 30 is shown in Figure 3. As shown in Figure 3, the mounting portions 30 have through-holes 34 through which bolts (fastening members) 32 can be inserted. Note that Figure 4 shows a side view of the vehicle 10, where four through-holes 34 are formed, but in Figure 3, due to the angle of the front part 12 of the vehicle, only three through-holes 34 are shown.

[0027] On the other hand, as shown in Figures 2 and 5, the motor unit 13 is provided with a mounting portion 36 that is fastened to the mounting portion 30 on the cast body 28 side, and the mounting portion 36 has a fastening hole 38 into which a bolt 32 is screwed.

[0028] Therefore, in this embodiment, the motor unit 13 is mounted (so-called mounted) to the cast body 28 by screwing (fastening) a bolt 32, which is inserted through a through hole 34 provided in the mounting portion 30 on the cast body 28 side, into a fastening hole 38 provided in the mounting portion 36 on the motor unit 13 side. Figure 5 is a cross-sectional view taken along line AA shown in Figure 4.

[0029] Furthermore, a pair of left and right wheel wells 14 are provided with suspension members (not shown). A mounting portion is provided at the center of the front member of this suspension member, which extends in the vehicle width direction, and the motor unit 13 is supported at three points, including this mounting portion.

[0030] Incidentally, as shown in Figures 2 and 4, the wheelhouse 14 is composed of a vertical wall portion 40 that extends in the vehicle's longitudinal direction and in the vehicle's vertical direction, and a plurality of ribs 42 are erected along the vehicle's width direction from the outer surface (outer surface) 40A of the vertical wall portion 40 in the vehicle's width direction.

[0031] As described above, in this embodiment, the left and right wheelhouses 14 and cross members 16 are integrally molded as a cast body 28 by die casting. The mold for molding the cast body 28 is, for example, not shown in the figure, a movable mold that moves along the vehicle's vertical direction relative to a fixed mold, thereby allowing the mold to open and close. In addition, to mold the outer surface of the cast body 28 in the vehicle's width direction, a slide core moves along the vehicle's width direction in accordance with the opening and closing of the mold.

[0032] Therefore, it is necessary to provide a draft angle on the surface of the cast body 28 along the direction of movement of the mold. The draft angle is predetermined based on the material of the cast body 28, the length in the drafting direction, etc.

[0033] In this embodiment, for example, the inner surface 40B side (motor unit 13 side) that constitutes the inner side in the vehicle width direction of the vertical wall portion 40 is formed by a fixed type and a movable type, and the outer surface 40A side of the vertical wall portion 40 is formed by a slide core including ribs 42, etc.

[0034] In this embodiment, as described above, the cast body 28 is provided with a mounting portion 30 to which the motor unit 13 is fastened. The mounting portion 30 is provided on the vertical wall portion 40 of the cast body 28, and on the inner surface 40B side of the vertical wall portion 40, as shown in Figure 6, the draft angle α of the mounting portion 30 and the draft angle α' (for example, about 3° in this case) of the general portion 44 excluding the mounting portion 30 are different.

[0035] In other words, in this embodiment, the draft angle α in the mounting portion 30 is a smaller angle than the draft angle α' in the general portion 44 (α < α'). Figure 6 is a cross-sectional view taken along the line BB shown in Figure 2. In this embodiment, the outer surface 40A of the vertical wall portion 40 is formed to be approximately parallel to the inner surface 40B of the vertical wall portion 40, in accordance with the draft angle α on the inner surface 40B of the vertical wall portion 40.

[0036] On the other hand, as shown in Figure 4, ribs 42 are erected on the outer surface 40A side of the vertical wall portion 40, extending outward in the vehicle width direction. Figure 4 mainly shows the ribs 42 around the mounting portion 30.

[0037] Here, we will specifically describe the multiple ribs 42 that are erected from the outer surface 40A of the vertical wall portion 40. In this embodiment, the front side member 20 of the cast body 28 is divided into a front portion 20A and a rear portion 20B along the longitudinal direction of the vehicle, and the front portion 20A and the rear portion 20B are separated by partition walls (ribs) 46 that extend in the vertical direction and the vehicle width direction, with the rear portion 20B protruding downwards from the front portion 20A.

[0038] On the front 20A side of the front side member 20, an upper wall portion (rib) 48 is provided, which constitutes the upper end of the front 20A side of the front side member 20 and extends in the vehicle longitudinal direction and vehicle width direction. Below the upper wall portion 48, a lateral wall portion (rib) 50 is provided, which extends in the vehicle longitudinal direction and vehicle width direction and is approximately parallel to the upper wall portion 48. Furthermore, below the lateral wall portion 50, a lower wall portion (rib) 52 is provided, which constitutes the lower end of the front 20A side of the front side member 20 and extends in the vehicle longitudinal direction and vehicle width direction and is approximately parallel to the lateral wall portion 50.

[0039] Furthermore, the rear end of the lower wall 52 is provided with an inclined wall 54 that slopes downward towards the rear of the vehicle as it approaches the rear of the vehicle, and this inclined wall 54 is connected to the partition wall 46. In addition, multiple vertical ribs 56 are provided between the upper wall 48 and the side wall 50, and between the side wall 50 and the lower wall 52, along the vertical direction of the vehicle.

[0040] On the other hand, on the rear 20B side of the front side member 20, an upper wall portion (rib) 58 is provided that connects to the upper wall portion 48 on the front 20A side of the front side member 20, forming the upper end on the rear 20B side of the front side member 20 and extending in the vehicle longitudinal direction and vehicle width direction. Furthermore, on the lower side of the upper wall portion 58, lateral wall portions (ribs) 60 and 62 are provided that connect to the lateral wall portion 50 and the lower wall portion 52 on the front 20A side of the front side member 20, respectively, and extend in the vehicle longitudinal direction and vehicle width direction.

[0041] Furthermore, a rib portion 64 is provided below the rib portion 62, extending in the vehicle's longitudinal direction and vehicle width direction, and is approximately parallel to the rib portion 62. Below the rib portion 64, a lower rib portion 66 is provided, forming the lower end of the rear 20B side of the front side member 20, and extending in the vehicle's longitudinal direction and vehicle width direction, and is approximately parallel to the rib portion 64.

[0042] Furthermore, between the upper wall 58 and the side wall 60, the side wall 60 and the side wall 62, the side wall 62 and the side wall 64, and the side wall 64 and the lower wall 52, there are multiple upward-sloping ribs (ribs) 68 that slope upward towards the rear of the vehicle, and downward-sloping ribs (ribs) 70 that slope downward towards the rear of the vehicle. The upward-sloping ribs 68 and the downward-sloping ribs 70 are provided continuously, forming an apparent truss structure between the upper wall 58, the side wall sections 60, 62, 64, and the lower wall 66.

[0043] As mentioned above, the mounting portion 30 of the cast body 28 has four through holes 34. Of the four through holes 34, through holes 34A and 34B, located on the front 20A side of the mounting portion 30, are positioned on the front 20A side of the front side member 20. Also, through holes 34C and 34D, located on the rear 20B side of the mounting portion 30, are positioned on the rear 20B side of the front side member 20.

[0044] Furthermore, the shape of the ribs 42 provided around the through-holes 34 differs between through-holes 34A, 34B and through-holes 34C, 34D. Through-hole 34A is provided within a rectangular rib 72 composed of a horizontal wall 50, a lower wall 52, vertical ribs 56, and a partition wall 46. Through-hole 34B is provided within a rectangular rib 74 composed of a lower wall 52, an inclined wall 54, vertical ribs 56, and a partition wall 46.

[0045] On the other hand, the through-hole 34C is provided within the truss-shaped rib 76, which is composed of the side wall portion 60, the side wall portion 62, the upward inclined rib 68, and the downward inclined rib 70. The through-hole 34D is provided within the truss-shaped rib 78, which is composed of the side wall portion 62, the side wall portion 64, the downward inclined rib 70, and the upward inclined rib 68.

[0046] In this embodiment, as shown in Figure 5, a bolt 32 is inserted into a through hole 34 formed in the mounting portion 30 of the cast body 28, and then the bolt 32 is screwed into a fastening hole 38 formed in the mounting portion 36 of the motor unit 13. The bolt 32 is fastened into the fastening hole 38 using a fastening tool such as an impact wrench.

[0047] <Function and Effects of Vehicle Frame Structure> Next, the operation and effects of the vehicle frame structure according to this embodiment will be described.

[0048] In this embodiment, as shown in Figures 1 to 3, the front part 12 of the vehicle to which the vehicle frame structure is applied is formed by die casting, and the cast body 28 is composed of vertical wall portions 40, a plurality of ribs 42 and through holes 34.

[0049] The vertical wall portion 40 is formed on the motor unit 13 side of the front part 12 of the vehicle and extends in the longitudinal and vertical directions of the vehicle. The multiple ribs 42 are erected from the vertical wall portion 40 outward in the vehicle width direction. Furthermore, the through hole 34 is provided in the vertical wall portion 40 and is formed within the area surrounded by the ribs 42.

[0050] To briefly explain the through-holes 34 and ribs 42, the through-holes 34A and 34B of the mounting portion 30 are provided within the rectangular ribs 72 and 74, respectively, while the through-holes 34C and 34D are provided within the truss-shaped ribs 76 and 78, respectively. In this embodiment, by providing these ribs 42 around the through-holes 34, it is possible to improve the rigidity of the vertical wall portion 40.

[0051] Then, bolts 32 are inserted through the through holes 34, and the mounting portion 36 of the motor unit 13 is fastened to the mounting portion 30 of the cast body 28 that constitutes the front part 12 of the vehicle via the bolts 32 and the vertical wall portion 40.

[0052] In this embodiment, on the inner surface 40B side (motor unit 13 side) that constitutes the inner side in the vehicle width direction of the vertical wall portion 40, the direction of release from the mold for forming the front part of the vehicle 12 is the vertical direction of the vehicle, and the draft angle α in the mounting portion 30 is a smaller angle than the draft angle α' in the general portion 44 (α < α'). Also, the outer surface 40A side of the vertical wall portion 40 is formed to be substantially parallel to the inner surface 40B of the vertical wall portion 40 in accordance with the draft angle α of the inner surface 40B side of the vertical wall portion 40.

[0053] In this embodiment, on the inner surface 40B side of the vertical wall portion 40, the draft angle α of the peripheral portion of the through hole 34 is smaller than the draft angle α' of the general portion 44. Therefore, the entry angle (α) of a fastening tool such as an impact wrench used when fastening the bolt 32 to a reference line P along the vehicle width direction can be made smaller than in the comparative example.

[0054] As a result, in this embodiment, interference between the fastening tool and the rib 42 can be avoided, eliminating the need to cut a part of the rib 42, such as by reducing its height, to avoid interference between the fastening tool and the rib 42. In this way, since there is no need to cut the rib 42, it is possible to ensure the rigidity required for the front part 12 of the vehicle.

[0055] In other words, in this embodiment, the mounting portion 30 of the vertical wall portion 40 of the die-cast cast body 28 ensures the rigidity required to mount the motor unit 13. Therefore, in this embodiment, there is no need to provide spacers or the like to ensure rigidity to the mounting portion 36 of the motor unit 13, and it is possible to fasten it directly with bolts.

[0056] Furthermore, in this embodiment, the outer surface 40A of the vertical wall portion 40 is formed at approximately the same angle as the draft angle α formed on the inner surface 40B of the vertical wall portion 40. This makes it possible to make the axial force of the bolt 32 approximately perpendicular to the fastening surface (outer surface 40A) of the bolt 32, thereby improving the fastening strength.

[0057] In the embodiments described above, an example of application to the front part 12 of the vehicle frame structure has been explained, but it goes without saying that it may also be applied to the rear part of the vehicle.

[0058] Furthermore, the present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0059] 10 vehicles 12 Front of the vehicle 13 Motor Unit 28 Cast body (vehicle frame component) 30 Mounting section (periphery of the through hole) 34 Through holes 40 Vertical wall section 40A Outer surface (outer surface of the vertical wall section) 40B Inner surface (inner surface of vertical wall) 42 Ribs 44 General section 46 Sectional Walls (Ribs) 48 Upper wall section (rib) 50 Side wall section (rib) 52 Lower wall section (rib) 54. Inclined wall (rib) 56 Vertical ribs (ribs) 58 Upper wall section (rib) 60 Side wall section (rib) 62 Side wall section (rib) 64 Side wall section (rib) 66 Lower wall section (rib) 68 Upward-sloping rib (rib) 70 Downward-sloping rib (rib) 72 Rectangular ribs (ribs) 74 Rectangular Ribs (Ribs) 76 Truss-shaped ribs (ribs) 78 Truss-shaped rib (rib) α Draft angle (draft angle around the through hole) α' Draft angle (draft angle of the general section)

Claims

1. A vehicle frame member is provided on the outside in the vehicle width direction of a motor unit that is located at the front or rear of the vehicle and drives the wheels, and extends in the vehicle longitudinal direction, and is made of die-cast material. The aforementioned vehicle frame member is A vertical wall portion formed on the motor unit side and extending in the vehicle's longitudinal direction and vertical direction, Multiple ribs are erected from the aforementioned vertical wall portion toward the outside in the vehicle width direction, A through hole formed within the region surrounded by the ribs in the vertical wall portion, through which a fastening member for fastening the motor unit is inserted, It consists of, A vehicle frame structure in which the direction of release from the mold for forming the vehicle frame member is the vertical direction of the vehicle, and on the inner surface that constitutes the inside in the vehicle width direction of the vertical wall portion, the draft angle of the area around the through hole is smaller than the draft angle of the general area excluding the area around the through hole.

2. The vehicle frame structure according to claim 1, wherein, in the area surrounding the through hole, the outer surface constituting the outer side in the vehicle width direction of the vertical wall portion is at approximately the same angle as the draft angle formed on the inner surface.

3. The vehicle frame structure according to claim 1, wherein some of the ribs among the plurality of ribs are provided in the area surrounding the through hole.

Images