Die-cast component

Abstract

To provide a die-cast component capable of achieving a thinner wall while maintaining strength.SOLUTION: A die-cast component 10 includes an aluminum member 11 and a reinforcing member 12 that is disposed inside the aluminum member 11 and is made of steel. The reinforcing member 12 is cast together with the aluminum member 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to die cast parts, and more particularly to die cast parts made of aluminum material. [Background technology]

[0002] Conventionally, such a technical field is described, for example, in Patent Document 1. The die-cast part described in Patent Document 1 is a member that constitutes the frame of an automobile, and is manufactured by a die-casting method using an aluminum alloy. Specifically, it is manufactured by injecting molten aluminum alloy into a mold at high speed and high pressure to instantly form a casting. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-179421 A Summary of the Invention [Problem to be solved by the invention]

[0004] When such die-cast parts are used as vehicle frames, their strength is reduced compared to vehicle frames formed from steel plates, so it is necessary to make the parts thicker to increase their strength. However, when the thickness of a die-cast part is increased, the size of the part increases, and the space occupied by the part also increases. This causes a problem of narrowing the space inside the vehicle cabin, the space inside the engine room, and the space for accommodating the battery and motor.

[0005] The present invention has been made to solve such technical problems, and has an object to provide a die-cast part that can be made thinner while maintaining its strength. [Means for solving the problem]

[0006] The die-cast part of the present invention comprises an aluminum member and a reinforcing member that is disposed inside the aluminum member and is made of steel, and the reinforcing member is cast into the aluminum member.

[0007] In the die-cast part according to the present invention, a reinforcing member made of steel is disposed inside an aluminum part, and the reinforcing member is cast in the aluminum part. Since the strength of steel is higher than that of aluminum, the aluminum part can be reinforced using the reinforcing member. This allows the die-cast part to have a smaller plate thickness while maintaining its strength, compared to a die-cast part made only of aluminum. This allows the die-cast part to be made thinner, and the die-cast part to be made smaller. In addition, since the reinforcing member is cast in the aluminum part, the joining strength between the reinforcing member and the aluminum part can be increased, compared to a case where the reinforcing member and the aluminum part are joined by welding, and the die-cast part can be easily manufactured. Furthermore, since the unit price of steel is lower than that of aluminum, the amount of aluminum material used can be reduced by using the reinforcing member, and the effect of reducing costs can also be expected.

[0008] In the die-cast component according to the present invention, the surface of the reinforcing member is preferably formed with projections and recesses. In this way, the projections and recesses on the surface of the reinforcing member exert an anchoring effect, thereby increasing the adhesion between the reinforcing member and the aluminum member and improving the bonding strength between them. As a result, peeling of the reinforcing member from the aluminum member can be prevented.

[0009] Furthermore, in the die-cast part according to the present invention, it is preferable that the die-cast part is in the form of a plate having a main surface, the reinforcing member is formed of a plurality of elongated steel materials, and the plurality of steel materials are arranged in a concentric shape when viewed from a direction perpendicular to the main surface. By arranging the plurality of steel materials in a concentric shape in this way, it is possible to uniformly increase the strength of the aluminum member in the radial direction of the concentric circles, and thus it is possible to suppress the difference in strength depending on the direction. As a result, it is possible to improve the strength of the entire die-cast part. Effect of the Invention

[0010] According to the present invention, it is possible to reduce the thickness of a die-cast part while maintaining the strength of the die-cast part. [Brief description of the drawings]

[0011] [Figure 1] 1A and 1B are a perspective view and a schematic cross-sectional view illustrating a die-cast part according to an embodiment. [Diagram 2] FIG. 2 is a schematic cross-sectional view for explaining thinning of a die-cast part. [Diagram 3] FIG. 11 is a schematic cross-sectional view showing a modified example of the die-cast part. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of a die-cast part according to the present invention will be described with reference to the drawings. In the description of the drawings, the same elements are given the same reference numerals and duplicated explanations will be omitted.

[0013] Fig. 1 shows a perspective view and a schematic cross-sectional view of a die-cast part according to an embodiment. The die-cast part 10 according to this embodiment is a part applied to the body structure of an automobile, and as shown in Fig. 1(a), for example, has a pair of left and right rear inside panels 20 and a pair of cross members 21 spanning between the pair of rear inside panels 20. The rear inside panels 20 and the cross members 21 are integrally formed by a die-casting method.

[0014] In this embodiment, the die-cast part 10 will be described as an example of a part having a rear inside panel 20 and a cross member 21, but the die-cast part of the present invention is not limited to this and may be, for example, a part having a pair of left and right front inside panels and a pair of cross members spanning between the pair of left and right front inside panels, a hood panel, a roof panel, etc.

[0015] Fig. 1(b) is a cross-sectional view taken along line AA in Fig. 1(a), i.e., a view showing a cross-section in the plate thickness direction of the die-cast part 10. As shown in Fig. 1(b), the die-cast part 10 includes an aluminum member 11 that serves as a base material, and a reinforcing member 12 that is disposed inside the aluminum member 11 and is made of steel. The reinforcing member 12 is cast into the aluminum member 11.

[0016] More specifically, the reinforcing member 12 is made of, for example, a plate-shaped steel material, is disposed inside the aluminum member 11 with its longitudinal direction aligned with the longitudinal direction of the aluminum member 11, and is cast into the aluminum member 11 by a die-casting method, thereby being integrated with the aluminum member 11. The reinforcing member 12 may be a single plate-shaped steel material having a relatively large area, or may be multiple plate-shaped steel materials having relatively small areas. When the reinforcing member 12 is multiple plate-shaped steel materials having relatively small areas, these steel materials are arranged side by side inside the aluminum member 11, for example, at equal intervals.

[0017] Furthermore, the reinforcing member 12 may be a plurality of cylindrical steel materials or the like. In this case, these steel materials are arranged side by side inside the aluminum member 11 at equal intervals, for example.

[0018] In addition, when the reinforcing member 12 is a plurality of steel materials, the juxtaposition direction of these steel materials can be changed as necessary. For example, the juxtaposition direction of the steel materials may be along the longitudinal direction of the aluminum member 11 or along the width direction of the aluminum member 11.

[0019] A die-cast part 10 having such a structure is manufactured, for example, by fixing a prefabricated reinforcing member 12 at a predetermined position in a die, and then injecting molten aluminum material into the die at high speed and pressure to form a casting of steel and aluminum material. Here, the difference between the melting point of steel (about 1200°C) and the melting point of aluminum material (about 660°C) is utilized, and after fixing the reinforcing member 12 in the die, molten aluminum at, for example, 700°C is injected. Because the melting point of steel is higher than 700°C, the placed steel material is cast integrally with the aluminum material without melting.

[0020] The surface of the reinforcing member 12, which is a steel material, is preferably formed with projections and recesses in order to improve adhesion between the reinforcing member 12 and the aluminum member 11. In this way, the projections and recesses on the surface of the reinforcing member 12 exert an anchor effect, so that the bonding strength between the reinforcing member 12 and the aluminum member 11 can be increased and peeling of the reinforcing member 12 from the aluminum member 11 can be prevented.

[0021] Furthermore, in order to prevent galvanic corrosion of dissimilar metals, it is preferable that the reinforcing member 12 is completely enclosed by the aluminum member 11. In this way, the interface between the steel material and the aluminum material (in other words, the interface between the reinforcing member 12 and the aluminum member 11) is not exposed to the outside, so that it is possible to prevent water from penetrating the interface.

[0022] On the other hand, as shown in Fig. 1(b) or 1(c), when the end of the reinforcing member 12 protrudes and is exposed from the aluminum member 11, it is preferable to seal the exposed interface between the reinforcing member 12 and the aluminum member 11 with a resin member 14 such as an adhesive in order to prevent galvanic corrosion. For example, in the case of a hybrid part of steel and aluminum material (i.e., a combined part of the reinforcing member 12 and the aluminum member 11) shown in Fig. 1(c), the exposed part of the reinforcing member 12 protruding from the aluminum member 11 is long, and the exposed interface between the reinforcing member 12 and the aluminum member 11 is sealed with the resin member 14. By using the resin member 14 in this way to prevent water from penetrating the exposed interface, it is possible to reliably prevent galvanic corrosion of dissimilar metals.

[0023] In the die-cast part 10 according to this embodiment, a reinforcing member 12 made of steel is disposed inside an aluminum part 11, and the reinforcing member 12 is cast into the aluminum part 11. Since the strength of steel is higher than that of aluminum, the reinforcing member 12 can be used to reinforce the aluminum part 11. This allows the plate thickness of the die-cast part 10 to be reduced while maintaining the strength of the die-cast part 10, as compared to a die-cast part made only of aluminum. This allows the die-cast part 10 to be made thinner, and the die-cast part 10 to be made smaller.

[0024] When the die-cast part 10 is used as a component of a vehicle interior, for example, a larger space can be secured in the vehicle interior by thinning the die-cast part 10. When the die-cast part 10 is used as a component of an engine room, a larger space can be secured in the engine room by thinning the die-cast part 10. When the die-cast part 10 is used as a component of a space for accommodating a battery or a motor, a larger space can be secured to accommodate the battery or the motor by thinning the die-cast part 10.

[0025] Furthermore, since the reinforcing member 12 is cast into the aluminum member 11, the joining strength between the reinforcing member 12 and the aluminum member 11 can be increased and the die-cast part 10 can be manufactured more easily than in the case where the reinforcing member 12 and the aluminum member 11 are joined by welding.

[0026] Since the Young's modulus of steel (about 210 GPa) is about three times that of aluminum (about 72 GPa), for example, on the premise of maintaining the same tensile strength, the thickness of the steel is about 1 / 3 of that of the aluminum. For example, as shown in Fig. 2(a), if the thickness of a conventional die-cast part made only of aluminum is 9 mm, and on the premise of maintaining the same tensile strength as the conventional part, if the conventional part is replaced with the die-cast part of the present invention, the thickness will be 7 mm (see Fig. 2(b)).

[0027] In this way, the plate thickness of the die-cast part 10 can be reduced, and thus the die-cast part 10 can be made thinner. This also makes it possible to reduce the amount of aluminum material used. Because the unit price of steel is cheaper than aluminum, the use of the reinforcing member 12 made of steel reduces the amount of aluminum material used, and this is expected to have the effect of reducing costs.

[0028] In addition to the above, various modifications of the die-cast part according to the present invention are possible. Some of the modifications will be described below with reference to FIG.

[0029] [Variation 1] In the first modification shown in Fig. 3(a), the die-cast part 10A is in the form of a plate having a main surface 13. The main surface 13 here means a main surface extending in the longitudinal direction of the die-cast part 10A, and may be a flat surface, a curved surface, or a surface having a complex shape including steps or the like, depending on the shape of the die-cast part 10A.

[0030] The reinforcing member 12A is formed of a plurality of long steel materials. When viewed from a direction perpendicular to the main surface 13, these steel materials are arranged in a mesh pattern. Specifically, the reinforcing member 12A is formed by arranging a plurality of steel materials in a lattice pattern. Each of these steel materials has a cylindrical shape and is joined to each other by welding or the like. Furthermore, a plurality of irregularities are regularly formed on the surface of each steel material.

[0031] In the die-cast part 10A configured in this manner, the reinforcing member 12A is formed from steel material arranged in a mesh pattern, thereby further increasing the strength of the die-cast part 10A compared to a case in which multiple steel materials are arranged in only one direction.

[0032] [Variation 2] In the second modification shown in Fig. 3(b), the die-cast part 10B has a plate shape having a main surface 13. The reinforcing member 12B is formed of a plurality of long steel materials. When viewed from a direction perpendicular to the main surface 13, these steel materials are arranged in a concentric shape. The circular steel materials are formed, for example, by joining both ends of the long steel materials by welding or the like.

[0033] In the die-cast part 10B configured in this manner, the reinforcing member 12B is formed of steel materials arranged in a concentric shape, so that the strength of the aluminum member 11 in the radial direction of the concentric circles can be uniformly increased. This makes it possible to suppress differences in strength depending on the direction, and improve the strength of the entire die-cast part 10B.

[0034] [Variation 3] In the third modification shown in FIG. 3(c), the reinforcing member 12C is formed of a plurality of corrugated steel members. These steel members are arranged at predetermined intervals inside the aluminum member 11, as shown in the cross-sectional view of FIG. 3(c). In the die-cast part 10C configured in this manner, the reinforcing member 12C is formed in a corrugated shape, which enhances the adhesion between the reinforcing member 12C and the aluminum member 11 and improves the joint strength between them. As a result, peeling of the reinforcing member 12C from the aluminum member 11 can be prevented.

[0035] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various design modifications can be made without departing from the spirit of the present invention as described in the claims. [Explanation of symbols]

[0036] 10, 10A, 10B, 10C: die-cast parts, 11: aluminum member, 12, 12A, 12B, 12C: reinforcing member, 13: main surface, 14: resin member, 20: rear inside panel, 21: cross member

Claims

[Claim 1] A die-cast part, An aluminum member; a reinforcing member disposed inside the aluminum member and made of steel; Equipped with A die-cast part, wherein the reinforcing member is cast into the aluminum member.

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