Vehicle support structure and method for manufacturing vehicle support structure

Abstract

An object of the present invention is to provide a vehicle support structure that can improve rigidity and further achieve weight reduction in a cast product of aluminum alloy. As a solution, a vehicle support structure (1) includes a main body portion (2) that rotatably supports an axle and a vehicle component mounting portion (3) extending from the main body portion (2). The vehicle component mounting portion (3) has a first protrusion (4), a second protrusion (5), and a third protrusion (6) that are triangularly arranged when viewed in the direction of the axle, a first connecting portion (7) that connects the first protrusion (4) and the third protrusion (6), and a second connecting portion (8) that connects the second protrusion (5) and the third protrusion (6). The vehicle support structure (1) is a cast product of aluminum or aluminum alloy. The first connecting portion (7) and the second connecting portion (8) are each formed to gradually incline so that the central portion in the length direction becomes thinner. A gate mark (9) exists on the side portion of the third protrusion (6) opposite to the main body portion.

Description

Technical Field

[0001] The present invention relates to a vehicle support structure for suspending a vehicle body by being mounted on the vehicle side and a method for manufacturing the vehicle support structure. Background Art

[0002] Conventionally, there has been known a vehicle support structure (Patent Document 1: Japanese Patent Laid-Open No. 2010-242821) having a structure in which bolts are passed through threaded holes formed in protruding portions at two positions on an arm mounting portion to mount and fix a trailing arm. In addition, a vehicle support structure has been proposed in which the trailing arm is mounted and fixed to protruding portions at three positions depending on the vehicle.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Laid-Open No. 2010-242821 Summary of the Invention

[0006] Technical Problem to be Solved by the Invention

[0007] Regarding the vehicle support structure, research is being conducted to cast using aluminum or an aluminum alloy in order to achieve weight reduction. However, in a structure in which vehicle components such as a trailing arm are mounted and fixed to protruding portions at three positions, there is a problem that holes are generated when the respective protruding portions are connected by a straight-shaped connecting portion.

[0008] Technical Solution for Solving the Technical Problem

[0009] The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle support structure and a method for manufacturing the vehicle support structure that are cast using aluminum or an aluminum alloy, can improve rigidity, and further achieve weight reduction.

[0010] As one embodiment, the above problems are solved by the solution disclosed below.

[0011] The vehicle support structure of the present invention includes a main body portion that rotatably shaft-supports an axle and a vehicle component mounting portion that extends from the main body portion. The vehicle component mounting portion has a first protruding portion, a second protruding portion, and a third protruding portion that are arranged in a triangular configuration when viewed in the direction of the axle, a first connecting portion that connects the first protruding portion and the third protruding portion, and a second connecting portion that connects the second protruding portion and the third protruding portion. The vehicle support structure is characterized in that it is a casting of aluminum or an aluminum alloy, the first connecting portion and the second connecting portion are each formed to gradually incline so that the central portion in the length direction becomes thinner, and a gate mark exists on the side portion of the third protruding portion opposite to the main body portion.

[0012] According to this structure, since casting is performed from the side of the third protrusion opposite to the main body portion, the middle portion of the connecting portion is thinnest, so that generation of holes can be prevented, rigidity can be increased, and further weight reduction can be achieved.

[0013] Preferably, the first connecting portion and the second connecting portion are each formed to be gradually inclined so as to become thinner in a direction perpendicular to the maximum load input direction of the load input to the vehicle component mounted on each protrusion portion. According to this structure, since the connecting portion is formed so as to become thinner in a direction perpendicular to the load input direction of the vehicle component, weight reduction is achieved and the connecting portion in the load input direction is thick, so that rigidity can be increased. Preferably, the cross-sectional shape perpendicular to the length direction of each of the first connecting portion and the second connecting portion is an H shape. According to this structure, since the cross-sectional shape perpendicular to the length direction is an H shape, rigidity can be further increased.

[0014] In the manufacturing method of the vehicle support structure of the present invention, the vehicle support structure includes a main body portion that rotatably shaft-supports an axle and a vehicle component mounting portion extending from the main body portion. The vehicle component mounting portion has a first protrusion portion, a second protrusion portion, and a third protrusion portion that are arranged in a triangular shape when viewed in the direction of the axle, a first connecting portion that connects the first protrusion portion and the third protrusion portion, and a second connecting portion that connects the second protrusion portion and the third protrusion portion. It is characterized in that molten aluminum or an aluminum alloy is poured into a molding die having a cavity in which the first connecting portion and the second connecting portion are each formed to be gradually inclined so as to become thinner at the central portion in the length direction and a gate provided at a position corresponding to the side of the third protrusion portion opposite to the main body portion. After that, while tilting the molding die so that the gate is in an upper position, pouring is completed and casting is performed.

[0015] According to this scheme, since the cavity is provided so that the middle portion of the connecting portion is thinnest, the main body portion is in a horizontal state and pouring is started from the gate arranged at the side of the third protrusion portion opposite to the main body portion. After that, while tilting the molding die so that the gate is in an upper position, pouring is completed and casting is performed, so that a reasonable casting that can prevent the generation of holes is achieved, and required rigidity can be maintained and weight reduction can be achieved.

[0016] Effects of the Invention

[0017] According to the disclosed vehicle support structure, generation of holes can be prevented, and the rigidity can be increased by using a casting of aluminum or an aluminum alloy, and further weight reduction can be achieved. Description of the Drawings

[0018] Figure 1 is a schematic perspective view showing an example of a vehicle support structure according to an embodiment of the present invention.

[0019] Figure 2 is Figure 1 a sectional view taken along line II-II of

[0020] Figure 3 is Figure 1 a sectional view taken along line III-III of

[0021] Figure 4 is a schematic perspective view showing an example of mounting and fixing a longitudinal arm in the vehicle support structure of Figure 1

[0022] Figure 5A is a schematic view showing an example of the pouring start state during casting using the manufacturing method of the vehicle support structure according to the present embodiment, Figure 5B is a schematic view showing an example of the pouring completion state after Figure 5A Detailed Description of the Embodiment

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Figure 1 is a schematic perspective view showing an example of the vehicle support structure 1 according to the present embodiment. It should be noted that in all the drawings used to describe the embodiments, components having the same function are denoted by the same reference numerals, and redundant descriptions may be omitted.

[0024] As Figure 1 shown, as an example, the vehicle support structure 1 of the present embodiment is a knuckle that supports both ends of a vehicle. The vehicle support structure 1 includes a main body portion 2 that rotatably supports an axle and a vehicle component mounting portion 3 that extends from the main body portion 2. The vehicle component mounting portion 3 has a first protrusion 4, a second protrusion 5, and a third protrusion 6 that are arranged in a triangular shape when viewed in the direction of the axle, a first connecting portion 7 that connects the first protrusion 4 and the third protrusion 6, and a second connecting portion 8 that connects the second protrusion 5 and the third protrusion 6. It is cast using aluminum or an aluminum alloy, and a gate mark 9 exists on the side portion of the third protrusion 6 that is opposite to the main body portion.

[0025] An axle hole 2a for inserting the axle is formed in the central portion of the main body portion 2, and a plurality of through holes 2b for mounting an axle hub are formed at a predetermined interval around the axle hole 2a. In Figure 1 the example of Figure 1 ​​A lower arm connecting portion 11 is formed on the lower side of the main body portion 2, an upper arm connecting portion 12 is formed on the upper side of the main body portion 2, and a caliper connecting portion 13 is formed on the obliquely upper side of the main body portion 2. Further, a vehicle component mounting portion 3 is formed by extending on the side opposite to the side of the main body portion 2 where the caliper connecting portion 13 is formed.

[0026] Figure 2 is Figure 1 a sectional view taken along line II-II of Figure 3 is Figure 1 a sectional view taken along line III-III of. As Figure 2 shown, the first connecting portion 7 and the second connecting portion 8 in the vehicle component mounting portion 3 are each formed to be gradually inclined so that the central portion in the length direction becomes thinner. And, as Figure 3 shown, the second connecting portion 8 is formed to be gradually inclined so that the central portion in the width direction becomes thinner, and the same applies to the first connecting portion 7. In Figure 3 the example of, the cross-sectional shape in the length direction of the second connecting portion 8 is an H shape, and the same applies to the first connecting portion 7.

[0027] Figure 4 is a schematic perspective view showing an example of mounting and fixing the longitudinal arm 14 to the vehicle support structure 1 in Figure 1 . Figure 4 The arrows in the vertical direction and the arrows in the front-rear direction in indicate the vertical and front-rear positional relationships when the vehicle support structure 1 is mounted on the vehicle. The longitudinal arm 14 is mounted and fixed to the protrusions at three positions by fixing members 15 such as screws and bolts. According to the present embodiment, since the first connecting portion 7 and the second connecting portion 8 are formed to be thinner in a direction perpendicular to the load input direction F with respect to the longitudinal arm 14, weight reduction can be achieved and the connecting portion in the load input direction F can be made thick, so that the rigidity can be increased. Moreover, since the cross-sectional shape perpendicular to the length direction of each of the first connecting portion 7 and the second connecting portion 8 is an H shape, the rigidity can be further increased. It should be noted that Figure 4 the load input direction F in is indicated by an arrow going from the front to the rear in the vehicle.

[0028] In the manufacturing method of the present embodiment, for a molding die having a cavity in which the first connecting portion 7 and the second connecting portion 8 are each formed to be gradually inclined so that the central portion in the length direction becomes thinner and a gate provided at a position corresponding to the side portion of the third protrusion 6 opposite to the main body portion, as Figure 5A shown, the main body portion is set to be in a horizontal state, and molten metal of aluminum or an aluminum alloy is poured starting from a state where the gate is in a side position. After that, as Figure 5BAs shown, it is set so that the main body is in a vertical state, and casting is performed by completing pouring while tilting the molding die so that the gate is in an upper position. This embodiment is gravity casting. According to this solution, since pouring starts from the gate arranged on the side opposite to the main body in the third convex part with the main body in a horizontal state, and then pouring is completed while tilting the molding die so that the gate is in an upper position to perform casting, it becomes a reasonable casting in which the molten metal liquid spreads throughout the cavity and the generation of holes can be prevented, and the required rigidity can be maintained and weight reduction can be further achieved. It should be noted that the gate is not limited to one place, and there are cases where gates are provided at multiple places. In addition, it is not limited to the above-mentioned gravity casting, and known casting techniques can be applied.

[0029] The present invention is not limited to the embodiments described above, and various changes can be made without departing from the scope of the present invention.

Claims

1. A vehicle support structure includes a main body portion that rotatably shaft-supports an axle, and a vehicle component mounting portion extending from the main body portion. The vehicle component mounting portion has a first protrusion, a second protrusion, and a third protrusion that are arranged in a triangular configuration when viewed in the direction of the axle, a first connecting portion that connects the first protrusion and the third protrusion, and a second connecting portion that connects the second protrusion and the third protrusion. It is characterized in that the vehicle support structure is a casting of aluminum or an aluminum alloy, the first connecting portion and the second connecting portion are each formed to gradually incline so that the central portion in the length direction becomes thinner, and a gate mark exists on the side portion of the third protrusion opposite to the main body portion.

2. The vehicle support structure according to claim 1, It is characterized in that the first connecting portion and the second connecting portion are each formed to gradually incline so that they become thinner in a direction perpendicular to the load input direction of the vehicle component mounted on each protrusion.

3. The vehicle support structure according to claim 1 or 2, It is characterized in that the cross-sectional shape of each of the first connecting portion and the second connecting portion perpendicular to the length direction is an H shape.

4. A manufacturing method of a vehicle support structure, the vehicle support structure includes a main body portion that rotatably shaft-supports an axle, and a vehicle component mounting portion extending from the main body portion. The vehicle component mounting portion has a first protrusion, a second protrusion, and a third protrusion that are arranged in a triangular configuration when viewed in the direction of the axle, a first connecting portion that connects the first protrusion and the third protrusion, and a second connecting portion that connects the second protrusion and the third protrusion. It is characterized in that molten aluminum or an aluminum alloy is poured into a molding die having a cavity in which the first connecting portion and the second connecting portion are each formed to gradually incline so that the central portion in the length direction becomes thinner, and a gate provided at a position corresponding to the side portion of the third protrusion opposite to the main body portion. Pouring is started when the main body portion is in a horizontal state and the gate is in a side position, and then casting is performed by completing pouring while tilting the molding die so that the gate is in an upper position.

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