mold

Abstract

Improves adhesion of mold release agents to recessed areas of a mold. [Solution] A mold (200) composed of a male mold (20) and a female mold (30) is used to manufacture vehicle body structural members including wheel arches, and fine irregularities are provided in the recessed inner portion (31A) of the inner surface of the female mold (30).

Description

[Technical Field]

[0001] The present disclosure relates to the structure of a mold used in manufacturing vehicle body structural members, including wheel arches. [Background technology]

[0002] In recent years, vehicle body structural members have been manufactured by casting. Patent Document 1 discloses a mold for manufacturing a suspension tower, which is a vehicle body structural member. The mold described in Patent Document 1 is composed of a fixed concave mold and a movable convex mold. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-202442 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, large vehicle body structural members have been manufactured by casting. When manufacturing vehicle body structural members by casting, a release agent is sprayed onto the surface of the mold to ensure smooth release of the product from the mold. However, since the molds used to manufacture large vehicle body structural members are deep, the release agent is sprayed using a long spray nozzle to ensure that the release agent is sufficiently adhered to the recessed parts of the mold.

[0005] However, long spray nozzles require complicated handling to avoid interference with the mold, which can result in longer casting cycle times.

[0006] Therefore, an object of the present disclosure is to improve the adhesion of a release agent to recessed areas of a mold. [Means for solving the problem]

[0007] The mold disclosed herein is a mold composed of a male mold and a female mold, and is used to manufacture vehicle body structural members including wheel arches, and is characterized in that fine irregularities are provided in a recessed portion of the inner surface of the female mold. [Effects of the Invention]

[0008] The present disclosure can improve the adhesion of a release agent to recessed areas of a mold. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a vehicle including a rear frame. [Figure 2] 2 is a perspective view showing a mold for manufacturing the rear frame shown in FIG. 1, showing a state in which a male mold and a female mold are combined in the up-down direction. FIG. [Figure 3] 3 is a side cross-sectional view of the mold in a state where the mold is set upright in a casting machine, taken along the line AA shown in FIG. 2. FIG. [Figure 4] 3 is a plan cross-sectional view of the mold in a state where the mold is set upright in a casting device, taken along the line BB shown in FIG. 2. [Figure 5] FIG. 4 is a detailed view of part C shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the mold 200 of the embodiment (see Figs. 2-5) will be described with reference to the drawings. First, with reference to Fig. 1, a vehicle 100 equipped with a rear frame 10 manufactured using the mold 200 will be described. Note that the symbols FR, UP, and LH in Fig. 1 indicate the front, upper, and left sides of the vehicle 100.

[0011] The rear frame 10 is a body structural member that constitutes the lower rear portion of the vehicle 100, and includes left and right wheel arches 11, a rear cross 12, and a rear floor 13. The rear frame 10 is an aluminum casting product, and the left and right wheel arches 11, the rear cross 12, and the rear floor 13 are integrally formed. The left and right wheel arches 11 are arch-shaped portions that house rear wheels therein. The rear cross 12 is a groove-shaped cross-section portion that connects the left and right wheel arches 11 in the vehicle width direction. The rear floor 13 is a plate-shaped portion that constitutes the floor behind the rear seats of the vehicle 100.

[0012] As shown in FIG. 2, the mold 200 for casting the rear frame 10 is composed of a male mold 20 and a female mold 30. When the male mold 20 and the female mold 30 are combined as shown in FIG. 2, a cavity 10A is formed into which molten metal flows. The cavity 10A includes a wheel arch portion cavity 11A for forming the wheel arch 11, a rear cross cavity 12A for forming the rear cross 12, and a rear floor cavity 13A for forming the rear floor 13. As shown in FIG. 2, the side of the female mold 30 is the front of the mold 200 (hereinafter referred to as the mold front), the side of the male mold 20 is the rear of the mold 200 (hereinafter referred to as the mold rear), and the vehicle front side of the rear frame 10 is above the mold 200 (hereinafter referred to as the mold top). Furthermore, the left side when facing the front of the mold 200 is the mold left.

[0013] As shown in Fig. 3, the mold 200 is erected by a crane (not shown) so that the mold top is facing upward in the direction of gravity, and is set in a casting machine (not shown). Fig. 3 is a side cross-sectional view of the mold 200 in an erected state and set in the casting machine, and is taken along the line AA shown in Fig. 2.

[0014] The female mold 30 in front of the mold is attached to a fixed plate of the casting machine. The male mold 20 in the rear of the mold is attached to a movable plate of the casting machine. The male mold 20 and the female mold 30 can be closed and opened by moving the movable plate of the casting machine in the front and rear directions. The solid line in Figure 3 indicates the state in which the male mold 20 is moved in the rear direction to open the male mold 20 and the female mold 30. The dashed line in Figure 3 indicates the state in which the male mold 20 is moved in the front direction to close the male mold 20 and the female mold 30. Figure 4 is a plan cross-sectional view of the mold 200 when it is set upright in the casting machine, and is the cross section BB shown in Figure 2. The solid line in Figure 4 indicates the state in which the male mold 20 and the female mold 30 are open, and the dashed line indicates the state in which the male mold 20 and the female mold 30 are closed.

[0015] 3 and 4, the male mold 20 has a semicircular convex portion 21, flat portions 22 and 25, and top, bottom, left, and right mating surfaces 23, 24, 26, and 27. The female mold 30 has a semicircular groove portion 31, flat recesses 32 and 35, and top, bottom, left, and right mating surfaces 33, 34, 36, and 37.

[0016] As shown by the dashed lines in Figures 3 and 4, when the male mold 20 is moved toward the front of the mold so that mating surfaces 23, 24, 26, and 27 of the male mold 20 align with mating surfaces 33, 34, 36, and 37 of the female mold 30, the protrusions 21 and grooves 31 form the wheel arch cavity 11A. The flat surface 22 and recessed portion 32 form the rear floor cavity 13A. The flat surface 25 and recessed portion 35 form the rear cross cavity 12A.

[0017] The casting device is equipped with a spray device 50 including a spray nozzle 52 that sprays the release agent onto the surface of the female mold 30 and a robot arm 51 that adjusts the position of the spray nozzle 52. When casting, as shown in Figures 3 and 4, the robot arm 51 inserts the spray nozzle 52 between the male mold 20 and the female mold 30 and sprays the release agent onto the inner surface of the groove 31.

[0018] As shown in FIG. 5, minute irregularities 38 are formed on the inner surface of the innermost portion 31A, which is the recessed portion of the groove portion 31 of the female mold 30. As shown in FIG. 5, the irregularities 38 may be formed by arranging grooves 31B in a linear, wavy, cross-hatched, or lattice pattern. In this case, the depth H of the grooves 31B may be 100 μm to 50 μm, the width W of the grooves 31B may be the same as the depth H, and the pitch P of the grooves 31B may be approximately twice the depth H. For example, if the depth H of the grooves 31B is 100 μm, the pitch P may be 200 μm, and if the depth H of the grooves 31B is 50 μm, the pitch P may be 100 μm.

[0019] Alternatively, the irregularities 38 may be roughened by, for example, a blasting process in which metal particles or sand grains are sprayed onto the surface. In this case, the inner surface of the groove 31 may be covered with a masking material or the like so that only the inner portion 31A of the groove 31 is roughened.

[0020] Furthermore, the irregularities 38 may be formed by surface processing using a laser to form the grooves 31B described above.

[0021] In the mold 200 of the embodiment, the innermost part 31A of the groove 31 of the female die 30 has fine irregularities 38, which increase the adhesion of the release agent to the inner surface. Therefore, even when the release agent is sprayed using a spray nozzle 52 of normal length, a sufficient amount of the release agent can be adhered to the inner surface of the innermost part 31A. This simplifies the handling of the spray nozzle 52, and shortens the cycle time of the casting process.

[0022] In the above explanation, it has been described that the irregularities 38 are provided in the innermost portion 31A of the groove portion 31 of the female mold 30, but this is not limited to this, and for example, the irregularities 38 may also be provided on the inner surface of the groove portion 31.

[0023] The spray nozzle 52 may have a narrower spray angle and a longer spray distance than a normal spray nozzle. [Explanation of symbols]

[0024] 10 rear frame, 10A cavity, 11 wheel arch, 11A wheel arch cavity, 12 rear cross, 12A rear cross cavity, 13 rear floor, 13A rear floor cavity, 20 male mold, 21 convex portion, 22, 25 flat portion, 23, 24, 33, 34 mating surface, 30 female mold, 31 groove portion, 31A back portion, 31B groove, 32, 35 concave portion, 38 unevenness, 50 spray device, 51 robot arm, 52 spray nozzle, 100 vehicle, 200 mold.

Claims

[Claim 1] A mold used to manufacture a vehicle body structural member including a wheel arch, the mold comprising a male mold and a female mold, The female mold has minute irregularities formed in a recessed portion of its inner surface. A mold characterized by:

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