Aluminum cast components

Abstract

This invention provides an aluminum cast member applicable to components of a vehicle that have energy-absorbing parts where energy absorption is required. [Solution] The aluminum cast member of this disclosure is an aluminum cast member used in a vehicle, and the aluminum cast member comprises a first member 12 cast in aluminum casting material in an energy absorption portion, and the first member 12 is formed of a material having greater ductility than the ductility of the aluminum casting material. For example, the aluminum cast member can be suitably used in a front side member 10 or a protective frame 61 on the side of a battery case 60.

Description

[[Technical Field]]

[0001] The present disclosure relates to an aluminum cast member used in vehicles. [[Background Art]]

[0002] Patent Document 1 discloses a dissimilar material joint structure in which a steel plate cast fitting is insert-molded with an aluminum insert-molding material, and the steel plate cast fitting is welded to a steel plate joining member, wherein the steel plate cast fitting is formed of a high-tensile steel plate with high tensile strength, anchor holes for mechanical joining with the aluminum insert-molding material are formed, and a non-alloyed zinc-based plating surface treatment is applied to keep the aluminum insert-molding material out of contact with the steel plate surface of the steel plate cast fitting.

[0003] In Patent Document 1, with the above dissimilar material joint structure, since the steel plate cast fitting is formed of a high-tensile steel plate with high tensile strength and anchor holes for mechanical joining with the aluminum insert-molding material are formed, the joining strength of the cast joint between the steel plate cast fitting and the aluminum insert-molding material (die-cast material) can be made greater than the welding joining strength between the steel plate and the cast fitting. Therefore, breakage caused by large input such as collision is limited to the welded joint portion that is easily visible from the appearance, enabling visual inspection and improvement in strength reliability. [[Prior Art Documents]] [[Patent Documents]]

[0004] [[Patent Document 1]] Japanese Unexamined Patent Application Publication No. 2011-235334 [[Summary of the Invention]] [[Problem to be Solved by the Invention]]

[0005] Incidentally, for example, in vehicles such as automobiles, aluminum cast members have come to be used in high-strength regions, but aluminum cast members generally have low elongation and are easily cracked by impact or the like.

[0006] Therefore, there are challenges in applying aluminum cast members to components that have energy-absorbing parts where energy absorption is required, such as in vehicle collisions.

[0007] This disclosure has been made in view of these circumstances, and one of its objectives is to provide an aluminum cast member applicable to a component having an energy-absorbing portion in a vehicle where energy absorption is required. [Means for solving the problem]

[0008] The aluminum cast member of this disclosure is an aluminum cast member used in a vehicle, The aluminum cast member comprises a first member cast in aluminum casting material in the energy absorption area. The first member is formed of a material having greater ductility than the aluminum casting material. [Effects of the Invention]

[0009] According to this disclosure, an aluminum cast member is provided that can be applied to a member having an energy-absorbing portion in a vehicle where energy absorption is required. [Brief explanation of the drawing]

[0010] [Figure 1] This is a plan view showing the front portion of a vehicle such as an automobile, as an example of an application of an aluminum cast member according to the embodiment of this disclosure. [Figure 2] This is a diagram illustrating a front side member using an aluminum cast member according to an embodiment of the present disclosure. [Figure 3] This figure shows the protective frame of a battery case using aluminum cast members according to an embodiment of the present disclosure. [Figure 4] This is a schematic diagram illustrating the state of the embodiment described herein when it is struck sideways against the battery case. [Modes for carrying out the invention]

[0011] Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as "embodiments") will be described in detail with reference to the attached drawings. Throughout the description of the embodiments, the same elements are assigned the same numbers or reference numerals.

[0012] Furthermore, the dimensional ratios in the drawings differ from the actual dimensional ratios and are merely for illustrative purposes to make the explanation easier to understand; there is no guarantee that identical parts are depicted with the same dimensions across different drawings.

[0013] Furthermore, for the sake of readability, in drawings, only some of the parts with the same attribute that exist in multiple locations may be assigned reference numerals.

[0014] <<Embodiment>> The aluminum cast members used in the vehicle of the embodiment described herein will be explained with reference to Figures 1 to 4. In the following embodiments, the aluminum cast member of the embodiment of this disclosure will be described in an example in which it is applied to the front side member 10 and the battery case 60. For example, an example of an aluminum cast component is an aluminum die-cast component, in which case the aluminum casting material is the aluminum die-cast material.

[0015] Figure 1 is a plan view showing the front portion of a vehicle such as an automobile, as an example of an application of an aluminum cast member according to the embodiment of this disclosure.

[0016] Figure 1 also includes coordinate axes indicating direction, where the Y direction is the vehicle width direction, the X direction is the vehicle front-to-back direction, and the Z direction is the vehicle height direction. In addition, coordinate axes indicating direction are also shown in other figures besides Figure 1.

[0017] As shown in Figure 1, a pair of front side members 10 extending in the front-to-rear direction of the vehicle are provided on both sides in the vehicle width direction. Furthermore, the front side member 10 uses an aluminum cast member (described later) according to the embodiment of this disclosure. Furthermore, the pair of front side members 10 form part of a vehicle body.

[0018] A crash box 20 is provided at a front end of each front side member 10, and the crash box 20 is fastened to the front side member 10 with a fastener such as a bolt, a nut, or the like.

[0019] Further, a front end of the crash box 20 is fastened to a bumper reinforcement 30 extending in a vehicle width direction with a fastener such as a bolt, a nut, or the like. For example, the bumper reinforcement 30 is formed of a metal plate.

[0020] Furthermore, a side sill 50 is fastened to a rear end of each front side member 10 via a torque box 40.

[0021] For example, the torque box 40 is a member having relatively high strength and rigidity, and is fastened to the rear end of each front side member 10 as well as to a front end of the side sill 50.

[0022] Specifically, the torque box 40 is fastened to the rear end of each front side member 10 with a fastener such as a bolt, a nut, or the like, and is fastened to the front end of the side sill 50 with a fastener such as a bolt, a nut, or the like.

[0023] In a vehicle in which a battery case 60 accommodating a battery B is mounted below a vehicle compartment, the torque box 40 may extend so as to cover a corner portion (a corner portion on a vehicle front side and a vehicle outer side) of the battery case 60 from the vehicle front side.

[0024] The battery case 60 includes a pair of protection frames 61 provided on lateral sides thereof. Specifically, the battery case 60 includes a case main body 62 that accommodates the battery B, and a pair of protection frames 61 integrally formed on lateral sides of the case main body 62 in the vehicle width direction.

[0025] In this embodiment, the protective frame 61 has a width that overlaps the side of the case body 62 with the underside of the side sill 50.

[0026] Although not shown in the diagram, the protective frame 61 is fastened to the side sill 50, for example, by bolts.

[0027] In this embodiment, the protective frame 61 is described as being integrally molded with the case body 62, but it may also be formed from a separate component from the case body 62 and positioned to the side of the case body 62.

[0028] In other words, the protective frame 61 only needs to be provided on the side of the battery case 60, regardless of whether it is integrally molded or not. If the protective frame 61 is provided on the side of the battery case 60 separately from the case body 62, the aluminum cast member of the embodiment may be used only for the protective frame 61.

[0029] Next, the front side member 10 and the battery case 60, which utilize the aluminum cast member of the embodiment, will be described in detail.

[0030] [Front side member 10] Figure 2 is a diagram illustrating a front side member 10 using an aluminum cast member according to an embodiment of the present disclosure, and is a cross-sectional view taken along line AA in Figure 1.

[0031] As shown in Figure 2, the aluminum cast member used in the front side member 10 comprises an aluminum cast material portion 11 formed from aluminum cast material, and a first member 12 provided within the aluminum cast material portion 11 and cast in aluminum cast material.

[0032] Specifically, by placing a first member 12, which has a shape matching the shape of the front side member 10, inside an aluminum casting mold, and then supplying aluminum casting material into the mold, an aluminum casting member is formed in which the first member 12 is encased in the aluminum casting material.

[0033] This first member 12 is provided in the energy absorption area, that is, the part of the front side member 10 that absorbs energy during a collision.

[0034] As shown in Figure 1, in this embodiment, the front side member 10 has a shape that extends in a substantially straight line in the longitudinal direction of the vehicle.

[0035] Furthermore, since the portion of the front side member 10 that needs to absorb collision energy extends along its entire length, the first member 12 is provided along almost the entire length of the front side member 10.

[0036] However, depending on the shape of the front side member 10, there may be cases where only a part of the front side member 10 needs to absorb the energy during a collision. In such cases, the first member 12 may be provided only in the part that needs to absorb the energy during the collision.

[0037] Furthermore, the first member 12 is formed from a material having greater ductility than the aluminum casting material of the aluminum casting material part 11. For example, the first member 12 is formed from iron or an aluminum wrought material.

[0038] Generally, aluminum cast members are hard and brittle, but by having a highly ductile first member 12 within the aluminum cast material part 11, the first member 12 can widely disperse the energy during a collision, thereby suppressing cracking due to impact.

[0039] Therefore, the aluminum cast member of this embodiment can be applied to energy-absorbing parts such as the front side member 10, where energy absorption from vehicle collisions and the like is required.

[0040] [Battery Case 60] Figure 3 is a diagram showing mainly the protective frame 61 of a battery case 60 using an aluminum cast member according to an embodiment of the present disclosure, and is a cross-sectional view taken along line BB in Figure 1.

[0041] As shown in Figure 3, the case body 62 of the battery case 60 forms a housing space S for housing a battery B (not shown) by combining the lower body 62L and the upper body 62U. The upper body 62U is a standard aluminum cast component (for example, made of die-cast aluminum) that does not have the first member 12.

[0042] Furthermore, a protective frame 61 is integrally molded to the side of the lower main body 62L. Specifically, the protective frame 61 is provided on the case body 62 side and comprises a first frame 61A connected to the lower body 62L, and a second frame 61B connected to the portion of the first frame 61A on the opposite side of the case body 62, with the first frame 61A and the second frame 61B integrally molded to the lower body 62L.

[0043] In this embodiment, the first frame 61A of the protective frame 61 comprises an aluminum cast material portion 11 formed from an aluminum cast material, and a first member 12 provided within the aluminum cast material portion 11 and cast in aluminum cast material.

[0044] Furthermore, the second frame 61B of the protective frame 61 comprises an aluminum cast material portion 11 formed from aluminum cast material, and a first member 12 provided within the aluminum cast material portion 11 and cast in aluminum cast material.

[0045] Specifically, by placing the first member 12 of the first frame 61A and the first member 12 of the second frame 61B in an aluminum casting mold that forms the lower body 62L, and then supplying aluminum casting material into the mold, an aluminum casting member (an aluminum casting member in which the lower body 62L and protective frame 61 are integrated) is formed in which the first member 12 is cast in aluminum casting material.

[0046] Furthermore, as explained earlier, the first member 12 of the first frame 61A and the first member 12 of the second frame 61B may be formed from a material having greater ductility than the aluminum casting material of the aluminum casting material portion 11.

[0047] For example, the first member 12 of the first frame 61A and the first member 12 of the second frame 61B may be made of iron, wrought aluminum, or the like.

[0048] Furthermore, the protective frame 61 may consist only of the second frame 61B, and as explained earlier, the protective frame 61 may be separate from the case body 62 (in this example, the lower body 62L).

[0049] In this embodiment, the first member 12 of the first frame 61A is provided with a collar portion WN, and the protective frame 61 is fastened to a nut (not shown) inside the side sill 50 (see Figure 1) by passing a bolt (not shown) through the collar portion WN.

[0050] On the other hand, as shown in Figure 3, the second frame 61B of the protective frame 61 is located on the outermost side in the vehicle width direction of the battery case 60, so it is preferable that it also has high rigidity.

[0051] Therefore, in this embodiment, the first member 12 of the second frame 61B of the protective frame 61 is made of a rectangular hollow material to ensure ductility while increasing rigidity. Furthermore, the shape of the hollow material is not limited to a rectangular shape.

[0052] As shown in Figure 1, in this embodiment, the protective frame 61 has a shape that extends in a nearly straight line in the longitudinal direction of the vehicle.

[0053] Furthermore, since the portion of the protective frame 61 that needs to absorb energy during a collision extends along its entire length, the first member 12 is provided along almost the entire length of the protective frame 61.

[0054] However, depending on the shape of the protective frame 61, there may be cases where only a part of the protective frame 61 needs to absorb the energy during a collision. In such cases, the first member 12 may be provided only in the part that needs to absorb the energy during the collision.

[0055] Figure 4 is a schematic diagram illustrating the state of the embodiment of the present disclosure when it is struck sideways against the battery case 60. Figure 4(A) shows the battery case 60 of the embodiment, and Figure 4(B) shows the battery case 600 of the comparative example.

[0056] The comparative battery case 600 has a protective frame 610 molded integrally with the case body 620 (specifically the lower body), but differs from the battery case 60 of the embodiment in that it is a normal aluminum cast member and does not have the first member 12 inside the protective frame 610. In Figure 4, the magnitude and range of stress when pole P collides with the side are indicated by the size and placement of the arrows.

[0057] As shown in Figure 4, when pole P collides with protective frame 61 and protective frame 610 from the side, the point at which the stress is greatest at the center of contact is the same for both battery case 60 and battery case 600.

[0058] On the other hand, the protective frame 61 of the embodiment has a highly ductile first member 12 inside, which allows for broad stress distribution, and as a result, there are no areas of high stress, thus suppressing the occurrence of cracks.

[0059] Conversely, the comparative example's protective frame 610 is a standard aluminum cast member that does not have the first member 12, and therefore is rigid. As a result, stress is not distributed but concentrated, leading to increased stress and making it prone to cracking.

[0060] Generally, aluminum cast members are hard and brittle, but by having a highly ductile first member 12 within the aluminum cast material part 11 (see Figure 3), the first member 12 widely disperses the energy during impact, thereby suppressing cracking due to impacts and the like.

[0061] Therefore, the aluminum cast member of this embodiment can be applied to energy-absorbing parts such as the protective frame 61 on the side of the battery case 60, where energy absorption from vehicle collisions and the like is required.

[0062] Although the above has been explained based on specific embodiments, this disclosure is not limited to the embodiments described above.

[0063] For example, potential energy absorption points could include fastening points with other components. One specific example would be the mounting points for suspension towers, where the suspension is attached.

[0064] In the case of such fastening parts, the first member 12 may be provided with a structure that includes a through hole through which a fastening threaded portion (for example, a male threaded portion) passes, and the first member 12 may be provided so that it is cast and encased in aluminum casting material within the aluminum casting member. Furthermore, the through-holes provided in the first member 12 may be provided in multiple locations as needed.

[0065] In this way, the first member 12 distributes the stress applied by other parts (for example, the suspension), thereby suppressing the occurrence of cracks and other damage.

[0066] Therefore, aluminum cast members can be applied to components having energy-absorbing parts, such as suspension towers in vehicles, where energy absorption is required.

[0067] Thus, the scope of this disclosure also includes modifications and improvements to the embodiments, which will be apparent to those skilled in the art from the claims. [Explanation of Symbols]

[0068] 10...Front side member, 12...First component, 60...Battery case, 61...Protective frame

Claims

1. Aluminum cast components used in vehicles, The aluminum cast member includes a first member cast in aluminum casting material in the energy absorption area. An aluminum cast member in which the first member is formed of a material having greater ductility than the ductility of the aluminum casting material.

2. The aforementioned aluminum cast member is a front side member, The energy absorption portion is a portion that absorbs the energy of the front side member during a collision. The aluminum cast member according to claim 1, wherein the first member has a shape that matches the shape of the front side member.

3. The aforementioned aluminum cast member is a protective frame on the side of the battery case. The energy absorption portion is a portion that absorbs the energy of the protective frame during a collision. The aluminum cast member according to claim 1, wherein the first member is a hollow material.

4. The energy absorption portion is a fastening portion with other members, The aluminum cast member according to claim 1, wherein the first member has a through hole through which a screw portion for fastening passes.

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