JP6971884B2 - Die-cast product - Google Patents

Description

The present invention relates to a die-cast product, and more particularly to the shape of a thin-walled portion forming at least a part of the die-cast product.

For example, aluminum die-cast products having at least a thin wall portion are used for various components of automobiles such as casings for engines and power transmission mechanisms. While this type of die-cast product is required to be further thinned due to the weight reduction of the vehicle body, it is important to secure the strength and rigidity required for the die-cast product.

Here, Patent Document 1 describes a thin-walled die-cast product as an automobile door panel, in which ribs for reinforcement are provided on one of the front and back sides of the die-cast product using the same material as the die-cast product body (aluminum molten metal having the same composition). The one integrally molded with the main body is disclosed.

Japanese Unexamined Patent Publication No. 2003-285150

In this way, if the ribs are integrally molded on one of the front and back sides of the die-cast product, the strength and rigidity of the die-cast product can be improved, but the weight of the die-cast product increases by the amount of the ribs, and the thickness of the die-cast product is thin. There is a problem that the effect of weight reduction due to the weight reduction is diminished.

In view of the above circumstances, in the present invention, it is a technical problem to be solved to provide a die-cast product capable of weight reduction while ensuring the required rigidity.

The solution to the above problems is achieved by the die-cast product according to the present invention. That is, this die-cast product is a die-cast product having a thin-walled portion at least in a part thereof, and the thin-walled portion has a convex portion protruding on one side of the front and back and a concave portion protruding in the opposite direction to the convex portion. A plurality of protrusions are provided so that a vertical wall portion extending in the vertical direction of the convex portion and a vertical wall portion extending in the vertical direction of the concave portion appear on an arbitrary virtual cross section that cuts the thin-walled portion in the front and back directions. It is characterized by the fact that the portions and the plurality of recesses are arranged in a predetermined pattern. The vertical wall portion of the convex portion referred to here is a convex portion appearing on a virtual cross section that cuts the thin-walled portion in the front-back direction, and is the front-back direction of the front-back direction of the thin-walled portion and the direction orthogonal to the front-back direction. It means a wall part that extends in a direction close to. Similarly, the vertical wall portion of the concave portion is a concave portion that appears on a virtual cross section that cuts the thin-walled portion in the front-back direction. It shall refer to the extending wall part.

As described above, in the present invention, in the field of die casting, attention is paid to the uneven shape of the thin-walled portion, which has not been conceived from the problem of formability (hot water flowability, etc.), and the thin-walled portion is cut in the front and back directions. A plurality of convex portions and a plurality of concave portions are arranged in a predetermined pattern on the thin-walled portion of the die-cast product so that the vertical wall portion of the convex portion and the vertical wall portion of the concave portion appear together on the virtual cross section. .. By arranging the plurality of convex portions and concave portions in the thin-walled portion in a predetermined pattern in this way, the thin-walled portion itself has a three-dimensional shape of unevenness having excellent rigidity. Therefore, the rigidity of the thin-walled portion can be improved without providing a reinforcing portion such as a rib, which makes it possible to improve the rigidity per unit weight (also referred to as rigidity efficiency). Further, by setting the arrangement pattern of the convex portion and the concave portion so that the vertical wall portion of the convex portion and the vertical wall portion of the concave portion appear on an arbitrary virtual cross section, the anisotropy related to the rigidity is eliminated or alleviated. Therefore, it is possible to increase the overall rigidity of the die-cast product.

Further, in the die-cast product according to the present invention, the convex portion may be a convex cross-sectional hat portion having a cross-sectional hat shape, and the concave portion may be a concave cross-sectional hat portion having a cross-sectional hat shape.

When the present inventors verified the thin-walled portion, particularly the flexural rigidity, by analysis or the like, a cross-sectional shape in which the convex portion was composed of a pair of vertical wall portions and a horizontal wall portion connecting the pair of vertical wall portions. That is, it was found that when the cross-sectional hat shape is formed, the performance (flexural rigidity) is extremely excellent. Therefore, it is possible to further improve the rigidity of the thin-walled portion by forming both the plurality of convex portions and concave portions to be arranged in the thin-walled portion into a hat shape in cross section.

Further, when both the convex portion and the concave portion have a cross-sectional hat shape, in the die-cast product according to the present invention, the vertical wall portion of the convex cross-sectional hat portion may also serve as the vertical wall portion of the concave cross-sectional hat portion.

In this way, by arranging both cross-section hat portions so that the vertical wall portion of the convex cross-section hat portion also serves as the vertical wall portion of the concave cross-section hat portion, for example, the convex cross-section hat portion and the concave cross-section hat portion can be obtained. Both cross-sectional hat portions can be continuously arranged without interposing a side wall portion for connection between the two. Therefore, for example, from the viewpoint of flexural rigidity, the cross-sectional area of the wall portion of the convex cross-sectional hat portion and the wall portion of the concave cross-sectional hat portion separated from the neutral axis (horizontal wall portion) occupies a large proportion. As a result, the section modulus can be efficiently increased. Therefore, it is possible to further improve the rigidity (particularly bending rigidity) of the thin-walled portion provided with these cross-sectional hat portions.

Further, when the convex portion and the concave portion each have a cross-sectional hat shape, in the die-cast product according to the present invention, the thickness dimension of at least a part of the vertical wall portion may be larger than that of the horizontal wall portion connected to the vertical wall portion.

As described above, by forming at least a part of the vertical wall portion thicker than the horizontal wall portion connected to the vertical wall portion, it is possible to further increase the rigidity against loads from various directions. Further, since only the vertical wall portion is formed to be thick, there is no concern that the weight reduction of the die-cast product as a whole will be hindered. From the above, according to this configuration, the rigidity efficiency of the thin-walled portion can be further improved. Furthermore, in the case of a die-cast product as in the present invention, it is relatively easy to partially change the wall thickness as described above depending on the shape setting of the mold (cavity), and the flow direction of the molten metal is different. By thickening the changing vertical wall portion, it is possible to effectively improve the flowability of the molten metal during casting. Therefore, it is possible to ensure the casting quality of the die-cast product while reducing the thickness of the die-cast product as a whole.

Further, when the convex portion and the concave portion each have a cross-sectional hat shape, in the die-cast product according to the present invention, the thickness dimension of the corner portion between at least a part of the vertical wall portion and the horizontal wall portion connected to the vertical wall portion is set. , May be larger than the side wall.

As described above, by forming at least a corner portion between the vertical wall portion and the horizontal wall portion to be thicker than the horizontal wall portion, it is possible to further increase the rigidity against loads from various directions. Further, since only a part of the wall portion (corner portion) is formed to be thick, there is no concern that the weight reduction of the die-cast product as a whole is hindered. From the above, according to this configuration, the rigidity efficiency of the thin-walled portion can be further improved. Further, in the case of a die-cast product, it is relatively easy to partially change the wall thickness as described above depending on the shape setting of the mold, and the flow direction of the molten metal changes between the vertical wall portion and the horizontal wall portion. By making the corners thicker, it is possible to improve the flowability of hot water during casting. Therefore, it is possible to ensure the casting quality of the die-cast product while reducing the thickness of the die-cast product as a whole.

Further, when the convex portion and the concave portion each have a cross-sectional hat shape, in the die-cast product according to the present invention, one convex cross-sectional hat portion and one concave hat portion are arranged in parallel in each of the regions obtained by dividing the square region into two. With the arranged uneven pattern as the minimum unit, four types of uneven patterns formed by rotating the uneven pattern by 90 ° around the front-back direction axis are arranged one by one in each of the regions divided into four square regions. The high-rigidity pattern may be aligned and arranged on the thin-walled portion.

As described above, in this configuration, the concave-convex pattern in which the convex cross-section hat portion and the concave cross-section hat portion are arranged in parallel one by one is set as the minimum pattern, and the concave-convex pattern is formed in each of the four divided square regions. High-rigidity patterns in which four types of uneven patterns having different orientations (longitudinal orientation and relative positional relationship of each cross-sectional hat portion) are arranged one by one are aligned and arranged on the thin-walled portion. In this way, a square region is composed of one of each of the four types of uneven patterns in which the directions of the uneven patterns are different from each other by 90 °, with the uneven pattern consisting of a pair of convex cross-section hats and concave cross-section hats as the minimum unit. It was found that when a pattern (high rigidity pattern) was formed, it showed extremely excellent rigidity against various loads. Therefore, by aligning and arranging the high-rigidity patterns having the above configuration on the thin-walled portion, it is possible to further improve the rigidity of the thin-walled portion.

Further, when the high-rigidity patterns having the above configuration are aligned and arranged on the thin-walled portion, in the die-cast product according to the present invention, one high-rigidity pattern is provided in the same posture in each of the quarterly divided regions. The same posture pattern arranged one by one may be aligned and arranged on the thin wall portion.

Alternatively, a high-rigidity pattern and three types of high-rigidity patterns in which the high-rigidity pattern is rotated by 90 ° around the front-back direction axis are arranged one by one in each of the regions divided into four square regions. The rotation pattern may be aligned and arranged on the thin wall portion.

Alternatively, each of the square regions divided into four has a high-rigidity pattern and three types of high-rigidity patterns, which are the upside-down, up-down, left-right, and up-down and left-right inversion of the high-rigidity pattern. The arranged inversion patterns may be aligned and arranged on the thin wall portion.

In this way, patterns that are arranged by arranging four high-rigidity patterns in the same orientation (posture), patterns that are arranged by rotating them by 90 °, or patterns that are arranged by inverting them vertically or horizontally are arranged. By arranging them, it is possible to increase the overall rigidity of the thin-walled portion against various loads.

Further, the solution of the above-mentioned problems is also achieved by the method for producing a die-cast product according to the present invention. That is, this manufacturing method has a thin-walled portion at least in a part thereof, and the thin-walled portion is provided with a convex portion protruding on one side of the front and back sides and a concave portion protruding in the opposite direction to the convex portion. A plurality of convex portions and a plurality of convex portions so that a vertical wall portion extending in the vertical direction of the convex portion and a vertical wall portion extending in the vertical direction of the concave portion appear on an arbitrary virtual cross section for cutting the thin portion in the front and back directions. It is a method of manufacturing a die-cast product in which the recesses are arranged in a predetermined pattern, and the mold clamping direction of the molding die provided with the cavity for molding the die-cast product is set to the thin wall of the die-cast product molded by the molding die. It is characterized by the point that the molten metal is injected into the cavity in the state of being set in the front and back directions of the portion.

As described above, also in the method for manufacturing the die-cast product according to the present invention, similarly to the die-cast product according to the present invention, the vertical wall portion of the convex portion and the vertical portion of the concave portion are formed on the virtual cross section for cutting the thin-walled portion in the front and back directions. A plurality of convex portions and a plurality of concave portions are arranged in a predetermined pattern on the thin-walled portion of the die-cast product so that the wall portion and the wall portion appear together. By arranging the plurality of convex portions and concave portions in the thin-walled portion in a predetermined pattern in this way, the rigidity of the thin-walled portion can be improved without providing a reinforcing portion such as a rib. Therefore, it is possible to improve the rigidity (rigidity efficiency) per unit weight. Further, by setting the arrangement pattern of the convex portion and the concave portion so that the vertical wall portion of the convex portion and the vertical wall portion of the concave portion appear on an arbitrary virtual cross section, the anisotropy related to the rigidity is eliminated or alleviated. Therefore, it is possible to increase the overall rigidity of the die-cast product.

Further, by injecting molten metal into the cavity in a state where the mold clamping direction of the molding die provided with the cavity for molding the die-cast product is set to the front and back directions of the thin-walled portion of the die-cast product molded by the molding die. , A thin-walled portion can be formed by using a movable mold and a fixed mold of a molding die that forms a cavity. Therefore, it is possible to stably manufacture a high-quality die-cast product by preventing an undercut portion from being generated in the region where the above-mentioned convex portion and concave portion are provided in the thin-walled portion.

Further, in the method for manufacturing a die-cast product according to the present invention, when a die-cast product having a disk-shaped thin-walled portion is injection-molded, an injection gate for injecting molten metal into the cavity is provided in a region corresponding to the thin-walled portion of the cavity. It may be opened toward the center side in the radial direction of.

In this way, when a die-cast product in which the thin-walled portion has a disk shape is injection-molded, the injection gate is attached to the molding die so as to open in the radial center side of the region corresponding to the thin-walled portion of the cavity. good. By installing the injection gate at the above-mentioned position, the injected molten metal spreads over the entire cavity as compared with the case where the injection gate opens at the radial outer end of the region corresponding to the thin portion of the cavity, for example. The required travel distance can be shortened (see, for example, FIG. 9 below). Therefore, even if the surface area of the thin-walled portion is increased by providing the convex portion and the concave portion in the thin-walled portion as described above, the moving distance of the molten metal from the injection gate is made uniform and the longest moving distance is shortened. can do. Alternatively, even if the heat capacity of the molten metal to be injected becomes smaller due to the thinning of the overall die-cast product, the moving distance after injection becomes shorter than before, so that the molten metal moving in the cavity can be used. It is possible to suppress the temperature decrease and prevent the quality deterioration due to poor hot water circulation and the like. From the above, according to this configuration, it is possible to stably obtain a die-cast product with excellent casting quality by improving the flowability of the molten metal while achieving both weight reduction and high rigidity of the die-cast product. It becomes.

As described above, according to the die-cast product according to the present invention, it is possible to provide a die-cast product capable of weight reduction while ensuring the required rigidity. Further, according to the method for manufacturing a die-cast product according to the present invention, it is possible to stably provide a die-cast product having excellent casting quality while achieving both weight reduction and high rigidity of the die-cast product.

It is a perspective view which shows the whole structure of the die-cast product which concerns on 1st Embodiment of this invention. It is a figure which looked at the thin-walled part of the die-cast product shown in FIG. 1 in a plan view. It is a top view of the convex part and the concave part provided in the thin-walled part shown in FIG. FIG. 3 is a cross-sectional view taken along the line AA of the convex portion and the concave portion shown in FIG. FIG. 3 is a plan view of a high-rigidity pattern in which a plurality of uneven patterns are arranged in a predetermined manner with the uneven pattern composed of the convex portion and the concave portion shown in FIG. 3 as the minimum unit. FIG. 5 is a plan view of an inverted pattern in which a plurality of high-rigidity patterns shown in FIG. 5 are arranged in a predetermined manner. FIG. 5 is a plan view of the same posture pattern in which a plurality of high-rigidity patterns shown in FIG. 5 are arranged in a predetermined manner. FIG. 5 is a plan view of a rotation pattern in which a plurality of high-rigidity patterns shown in FIG. 5 are arranged in a predetermined manner. It is sectional drawing of the main part of the casting apparatus used for casting molding of the die-cast product which concerns on 1st Embodiment of this invention. FIG. 3 is an enlarged cross-sectional view of a main part of a thin-walled portion of a die-cast product according to a second embodiment of the present invention, and is a cross-sectional view of a convex portion and a concave portion provided in the thin-walled portion. FIG. 3 is an enlarged cross-sectional view of a main part of a thin-walled portion of a die-cast product according to a third embodiment of the present invention, and is a cross-sectional view of a convex portion and a concave portion provided in the thin-walled portion. FIG. 3 is an enlarged cross-sectional view of a main part of a thin-walled portion of a die-cast product according to a fourth embodiment of the present invention, and is a cross-sectional view of a convex portion and a concave portion provided in the thin-walled portion.

Hereinafter, the contents of the die-cast product and the manufacturing method thereof according to the first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing the overall shape of the die-cast product 1 according to the present embodiment, and FIG. 2 is a plan view of the thin-walled portion 2 of the die-cast product 1. As shown in FIGS. 1 and 2, the die-cast product 1 has a disk-shaped thin-walled portion 2, a tubular portion 3 connected to the thin-walled portion 2 on the radial outer side thereof, and a flange portion 4 connected to the tubular portion 3. And have one. The flange portion 4 is formed to be thicker than the thin wall portion 2. Hereinafter, the shape of the thin-walled portion 2 will be mainly described.

The thin-walled portion 2 is provided with a convex portion 5 projecting on one side in the front-back direction (direction orthogonal to the paper surface in FIG. 2) and a concave portion 6 projecting in the opposite direction to the convex portion 5 in the front-back direction. Has been done. Here, the shape of the convex portion 5 is arbitrary, and in the present embodiment, as shown in FIGS. 3 and 4, the convex portion 5 extends linearly along a predetermined direction (vertical direction in FIG. 3), and is paired. It has a cross-sectional hat shape including a vertical wall portion 7 and 7 and a horizontal wall portion 8 connecting the pair of vertical wall portions 7 and 7 to each other. The shape of the concave portion 6 is also arbitrary, and in the present embodiment, as shown in FIGS. 3 and 4, the concave portion 6 extends linearly along a predetermined direction, and the pair of vertical wall portions 9, 9 And a horizontal wall portion 10 connecting the pair of vertical wall portions 9, 9 to each other, forming a cross-sectional hat shape. Further, in the present embodiment, the vertical wall portion 7 of the convex portion 5 also serves as the vertical wall portion 9 of the concave portion 6. In other words, the convex portion 5 and the concave portion 6 share one vertical wall portion 7 (9). As a result, the convex portion 5 and the concave portion 6 are in the closest contact state in the lateral direction (left-right direction in FIG. 3).

As shown in FIG. 3, for example, the convex portion 5 and the concave portion 6 having the above configuration form a concavo-convex pattern 11 in which the square region S1 is divided into two regions (divided regions S11 and S12) and arranged in parallel with each other. do. In this case, the longitudinal dimension L1 of the convex portion 5 and the longitudinal dimension L2 of the concave portion 6 are the same. Further, the lateral dimension D1 of the convex portion 5 and the lateral dimension D2 of the concave portion 6 are the same.

Further, as shown in FIG. 4, the distance y1 from the neutral axis X to the side wall portion 8 of the convex portion 5 and the distance y2 from the neutral axis X to the side wall portion 10 of the concave portion 6 in the cross section of the concave-convex pattern 11 are arbitrary. However, it is desirable that they are equal from the viewpoint of the section modulus. Regarding the relationship between the thickness dimension t1 (t2) of the side wall portion 8 (10) and the distance y1 (y2), the distance y1 (y2) is also a ratio to the thickness dimension t1 (t2) from the viewpoint of the section modulus. Is set to 2.0 or higher, preferably 3.0 or higher, and more preferably 4.0 or higher. In this case, the thickness dimension t1 (t2) of the side wall portion 8 (10) is set to 2.0 mm or less, preferably 1.5 mm or less, and more preferably 1.0 mm from the viewpoint of weight reduction. It is set to the following. Of course, the above numerical range is only an example, and for example, the distance y1 (y2) may be set to less than 2.0 in ratio to the thickness dimension t1 (t2), and the thickness dimension of the side wall portion 8 (10) may be set. t1 (t2) may be set to be larger than 2.0 mm.

Further, as shown in FIG. 4, the gradient of the vertical wall portion 7 (9) (here, the angle θ formed by the vertical wall portion 7 (9) with respect to the direction orthogonal to the neutral axis X) is the maximum section coefficient. It is preferable to set the temperature to 0 °, but on the other hand, the smaller the gradient of the vertical wall portion 7 (9), the more the mold release resistance tends to increase. From the above viewpoint, the gradient of the vertical wall portion 7 (9) is preferably 10 ° or more and 20 ° or less, and more preferably 12 ° or more and 18 ° or less.

In the uneven pattern 11 having the above configuration, one or more vertical wall portions 7 of the convex portions 5 and vertical wall portions 9 of the concave portions 6 appear on an arbitrary virtual cross section for cutting the thin portion 2 in the front and back directions. As described above, they are arranged on the thin-walled portion 2 in a predetermined pattern. Hereinafter, an example of the arrangement pattern will be described.

FIG. 5 shows a plan view of a high-rigidity pattern 12 in which a plurality of uneven patterns 11 shown in FIG. 3 are arranged in a predetermined manner. In this high-rigidity pattern 12, the concave-convex pattern 11 is formed in each of the regions (divided regions S21 to S24) in which the square region S2, which is four times larger than the square region S1 described above, is divided into four, in the front-back direction (the paper surface in FIG. 3). Four types of unevenness patterns 11a to 11d, which are orthogonal to each other and are rotated by 90 ° around the axis (up and down direction in FIG. 4), are arranged one by one. In the present embodiment, the convex portion 5 constituting one unevenness pattern 11 (for example, the upper left unevenness pattern 11a) and another unevenness pattern adjacent to the unevenness pattern 11a (for example, the lower left unevenness pattern 11c) are configured. The convex portion 5 is a continuous form in which the horizontal wall portions 8 and 8 are continuous without passing through the vertical wall portion 7. Similarly, with respect to the concave portion 6, the concave portion 6 constituting one unevenness pattern (for example, the unevenness pattern 11a on the upper left) and the concave portion constituting another unevenness pattern (for example, the unevenness pattern 11b on the upper right) adjacent to the unevenness pattern 11a. 6 means that the horizontal wall portions 10 and 10 are continuous with each other without the vertical wall portion 9 being interposed.

The high-rigidity pattern 12 having the above configuration constitutes an inversion pattern 13 arranged in the manner shown in FIG. 6, for example. The inversion pattern 13 includes the high-rigidity pattern 12 (12a) in the posture shown in FIG. 5 in each of the regions (divided regions S31 to S34) in which the square region S3, which is four times larger than the square region S2 described above, is divided into four. Three types of high-rigidity patterns 12b to 12d, in which the high-rigidity pattern 12a is inverted left and right, inverted up and down, and inverted left and right and up and down, are arranged one by one. Also in this arrangement pattern, in the present embodiment, the convex portion 5 constituting one high-rigidity pattern 12 (for example, the high-rigidity pattern 12a on the upper left) and another high-rigidity pattern adjacent to the high-rigidity pattern 12a. The convex portions 5 constituting (for example, the high-rigidity pattern 12b on the upper right) are continuous with the horizontal wall portions 8 and 8 without interposing the vertical wall portions 7. Similarly, for the recess 6, the recess 6 constituting one high-rigidity pattern 12 (for example, the high-rigidity pattern 12a on the upper left) and the concave portion 6 constituting the high-rigidity pattern 12 (for example, the high-rigidity pattern 12c on the lower left). Is continuous with the horizontal wall portions 10 and 10 without passing through the vertical wall portion 9.

As shown in FIGS. 1 and 2, the plurality of inverted patterns 13 having the above configuration are aligned and arranged on the thin-walled portion 2 of the die-cast product 1. As a result, the thin-walled portion 2 is formed so that the vertical wall portion 7 of the convex portion 5 and the vertical wall portion 9 of the concave portion 6 appear on an arbitrary virtual cross section for cutting the thin-walled portion 2 in the front and back directions. 2 itself forms a concave-convex shape of a predetermined pattern. In this case, the arrangement pattern of the convex portion 5 and the concave portion 6 appearing on one of the front and back surfaces of the thin-walled portion 2 and the arrangement pattern of the convex portion 5 and the concave portion 6 appearing on the other front and back surfaces of the thin-walled portion 2 are inverted. It will be the same in the state.

As described above, in the die-cast product 1 according to the present invention, the vertical wall portion 7 of the convex portion 5 and the vertical wall portion of the concave portion 6 are formed on a virtual cross section for cutting at least a part of the thin-walled portion 2 in the front and back directions. The plurality of convex portions 5 and the plurality of concave portions 6 are arranged in the thin-walled portion 2 in a predetermined pattern so that one or more of the 9's appear together. According to this configuration, since the thin-walled portion 2 itself has a three-dimensional uneven shape having excellent rigidity, the rigidity of the thin-walled portion 2 can be improved without providing a reinforcing portion such as a rib. Therefore, it is possible to improve the rigidity of the thin portion 2 per unit weight. Further, by setting the arrangement pattern of the convex portion 5 and the concave portion 6 so that one or more of the vertical wall portion 7 of the convex portion 5 and the vertical wall portion 9 of the concave portion 6 appear on an arbitrary virtual cross section. It is possible to eliminate or alleviate the anisotropy related to rigidity and increase the overall rigidity of the die-cast product 1.

Further, in the present embodiment, the convex portion 5 is a convex cross-sectional hat portion having a cross-sectional hat shape, and the concave portion 6 is a concave cross-sectional hat portion having the same cross-sectional hat shape (see FIG. 4). This makes it possible to further improve the rigidity of the thin-walled portion 2. Further, when both the convex portion 5 and the concave portion 6 have a cross-sectional hat shape, the convex portion 5 and the concave portion 6 are arranged adjacent to each other so that the vertical wall portion 7 of the convex portion 5 also serves as the vertical wall portion 9 of the concave portion 6. Therefore, the cross-sectional coefficient of the uneven pattern 11 including each of the convex portion 5 and the concave portion 6 can be efficiently increased. Therefore, it is possible to further improve the rigidity (particularly bending rigidity) of the thin-walled portion 2 formed by arranging these uneven patterns 11 in a predetermined manner. Specifically, by arranging the high-rigidity patterns 12 shown in FIG. 5 in an aligned manner in the manner shown in FIG. 6, it is possible to improve the overall rigidity including the bending rigidity of the thin-walled portion 2.

In this embodiment, as an arrangement pattern of the convex portion 5 and the concave portion 6 arranged on the thin-walled portion 2, a high-rigidity pattern 12 arranged in an aligned manner (inversion pattern 13) is exemplified. Of course, it is also possible to take other arrangement modes. FIG. 7 shows an example thereof, and the same posture pattern 14, which is an arrangement pattern of the convex portion 5 and the concave portion 6 shown in the figure, is each of the above-mentioned square regions S3 divided into four regions (divided regions S31 to S34). In addition, all four high-rigidity patterns 12 are arranged one by one in the same posture. Therefore, by arranging the same number of posture patterns 14 having the same configuration on the thin-walled portion 2, it is possible to reduce the weight of the die-cast product 1 while ensuring the rigidity of the thin-walled portion 2.

Alternatively, the high-rigidity pattern 12 can be aligned and arranged in the manner shown in FIG. The rotation pattern 15, which is an arrangement pattern of the convex portions 5 and the concave portions 6 shown in the figure, has a high-rigidity pattern 12 and a high-rigidity pattern in each of the above-mentioned square regions S3 divided into four regions (divided regions S31 to S34). Three types of high-rigidity patterns 12 (12e to 12g) formed by rotating 12 around its front-back direction axis by 90 ° are arranged one by one. Therefore, by arranging the plurality of rotation patterns 15 having the above configuration in an aligned manner on the thin-walled portion 2, it is possible to reduce the weight of the die-cast product 1 while ensuring the rigidity of the thin-walled portion 2.

The die-cast product 1 according to the above description can be manufactured by using, for example, the casting apparatus shown in FIG. Hereinafter, the configuration of the casting apparatus 50 will be described, and then an example of the manufacturing process of the die-cast product 1 using the casting apparatus 50 will be described.

The casting apparatus 50 shown in FIG. 9 includes a fixed platen 51, a movable platen 52, an intermediate mold 53 fixed to the fixed platen 51, a fixed mold 54 (fixed insert) attached to the intermediate mold 53, and a movable platen. A movable mold 55 (movable insert) attached to 52, a cavity 56 formed between the fixed mold 54 and the movable mold 55 by mold clamping, and an intermediate mold 53 are provided. An injection gate 57 that opens at a predetermined position in the cavity 56, and an injection sleeve 58 that is connected to the injection gate 57 and is attached to the fixed platen 51 so as to penetrate the fixed platen 51 along the mold clamping direction. It mainly includes an injection sleeve 58 and a plunger 59 that fits slidably.

Here, the region 56a of the cavity 56 corresponding to the thin-walled portion 2 of the die-cast product 1 is partitioned only by the fixed mold 54 and the movable mold 55, and the fixed mold 54 and the movable mold 55 are formed. The mold clamping direction is aligned with the front and back directions (left-right direction in FIG. 9) of the thin-walled portion 2 of the die-cast product 1 formed by the fixed mold 54 and the movable mold 55. As a result, interference between the die-cast product 1 and the movable mold 55 can be avoided due to the mold opening operation after casting. Of course, as long as interference with the thin-walled portion 2 (of which the above-mentioned region where the arrangement pattern of the convex portion 5 and the concave portion 6 is provided) is avoided, the illustration is omitted, but the fixed mold 54 and the movable mold 55 One or both of them may be provided with a structure such as a slide core that can move in a direction different from the mold clamping direction between the fixed mold 54 and the movable mold 55.

Further, in the present embodiment, the injection gate 57 is located on the radial center side of the thin-walled portion 2 of the die-cast product 1 in the cavity 56 (if the die-cast product 1 is in the form shown in FIG. 1, for example, the radius of the thin-walled portion 2). An injection gate 57 is attached to the intermediate mold 53 and the fixed mold 54 so as to open around the hole provided in the center of the direction).

Casting and molding of the die-cast product 1 using the casting apparatus 50 having the above configuration is performed, for example, as follows. First, molten metal such as aluminum is poured into the injection sleeve 58 through an opening (not shown) provided above the injection sleeve 58, and the molten metal in the poured state is injected by pressing the plunger 59. By sending out to the cavity 56 through the gate 57, the molten metal is injected into the cavity 56. At this time, since the injection gate 57 is open on the radial center side of the region 56a corresponding to the thin wall portion 2 of the cavity 56, the molten metal injected into the cavity 56 through the injection gate 57 is the cavity 56. Moves from the center side in the radial direction to the outside in the radial direction (direction indicated by the broken line arrow in FIG. 9). As a result, the entire area of the cavity 56 including the region 56a corresponding to the thin-walled portion 2 is filled without leakage, and the die-cast product 1 having a shape corresponding to the cavity 56 is formed by cooling.

In this way, the region 56a of the cavity 56 corresponding to the thin-walled portion 2 of the die-cast product 1 is partitioned only by the fixed mold 54 and the movable mold 55, and the fixed mold 54 and the movable mold 55 are clamped. By injecting the molten metal into the cavity 56 with the direction set to the front and back directions of the thin-walled portion 2 (corresponding region 56a), the region of the thin-walled portion 2 where the above-mentioned convex portion 5 and concave portion 6 are provided. It is possible to stably manufacture a high-quality die-cast product 1 by preventing a situation in which an undercut portion is generated.

Further, when the die-cast product 1 in which the thin-walled portion 2 has a disk shape is injection-molded as in the present embodiment, the injection gate 57 is placed on the radial center side of the region 56a corresponding to the thin-walled portion 2 of the cavity 56. By attaching to the intermediate mold 53 so as to open to, for example, although not shown, the injected molten metal is compared with the case where the injection gate 57 is provided at the radial outer end of the region 56a corresponding to the thin wall portion 2. Can reduce the travel distance required to reach the entire cavity 56 (see FIG. 9). Therefore, even if the surface area of the thin-walled portion 2 is increased by the amount of the convex portion 5 and the concave portion 6 provided in the thin-walled portion 2 as described above, the moving distance of the molten metal from the injection gate 57 is made uniform. The maximum travel distance can be shortened. Alternatively, even if the heat capacity of the molten metal to be injected is reduced due to the overall thinning of the die-cast product 1 (particularly the thinning of the thin portion 2), the moving distance after injection is shorter than before. Therefore, it is possible to suppress a decrease in the temperature of the molten metal moving in the cavity 56 and prevent a deterioration in quality due to poor rotation of the molten metal or the like. Therefore, according to the casting apparatus 50 according to the present embodiment, the die-cast product 1 has excellent casting quality by improving the flowability of the molten metal while achieving both weight reduction and high rigidity of the die-cast product 1. It is possible to obtain it stably.

Although one embodiment (first embodiment) of the present invention has been described above, the die-cast product and the manufacturing method thereof according to the present invention may adopt a configuration other than the above as long as the purpose is not deviated. ..

For example, in the above embodiment, when the thickness dimensions t1 to t4 of the wall portions (here, the vertical wall portions 7, 9 and the horizontal wall portions 8, 10) constituting the convex portion 5 and the concave portion 6 having a cross-sectional hat shape are constant. (See FIG. 4), but if necessary, a part of the wall portion constituting the convex portion 5 or the concave portion 6 may be formed to be thicker than the remaining wall portion. FIG. 10 shows an enlarged cross-sectional view of a main part of the thin-walled portion 2 of the die-cast product 1 according to an example thereof (second embodiment of the present invention). As shown in the figure, in the die-cast product 1 according to the present embodiment, at least a part of the vertical wall portion 7 of the convex portion 5 and the vertical wall portion 9 of the concave portion 6 provided in the thin wall portion 2 The thickness dimensions t3 and t4 of 7 and 9 are larger than the thickness dimensions t1 and t2 of the horizontal wall portions 8 and 10 connected to the vertical wall portions 7 and 9. Specifically, the thickness dimensions t3 and t4 of the vertical wall portions 7 and 9 are set to 1.5 or more, preferably 2.0, in comparison with the thickness dimensions t1 and t2 of the horizontal wall portions 8 and 10, respectively. It is set to the above. The region where the vertical wall portions 7 and 9 are set to be thicker than the horizontal wall portions 8 and 10 may be a part of the vertical wall portions 7 and 9, for example, the uneven pattern 11 of the convex portion 5 and the concave portion 6 may be formed. When the high-rigidity pattern 12 shown in FIG. 5 is formed, the central region B of the high-rigidity pattern 12 whose rigidity tends to be relatively low (in other words, the longitudinal end of the convex portion 5 or the concave portion 6 of each uneven pattern 11a to 11d). Only the vertical wall portions 7 and 9 constituting (the portion where the portions intersect from all sides) may be formed to be thicker than the horizontal wall portions 8 and 10.

By forming a part of the vertical wall portions 7 and 9 thicker than the horizontal wall portions 8 and 10 in this way, it is possible to further increase the rigidity of the thin wall portion 2 with respect to loads from various directions. Further, when only a part of the vertical wall portions 7 and 9 is formed to be thick, there is no concern that the weight reduction of the die-cast product 1 as a whole is hindered. From the above, according to this configuration, the rigidity efficiency of the thin wall portion 2 can be further improved. Furthermore, in the case of the die-cast product 1, it is relatively easy to partially change the wall thickness as described above depending on the shape setting of the cavity 56 (fixed mold 54 and movable mold 55), and the molten metal is melted. By thickening the vertical wall portions 7 and 9 whose flow direction changes, it is possible to effectively improve the flowability of the hot water during casting. Therefore, it is possible to secure the casting quality of the die-cast product 1 while trying to reduce the thickness of the die-cast product 1 as a whole.

Further, in the above embodiment, the thickness dimensions t5 and t6 of the corner portions 16 and 17 between the vertical wall portions 7 and 9 and the horizontal wall portions 8 and 10 of the convex portion 5 having a cross-sectional hat shape and the concave portion 6 are the vertical walls. An example is shown in which the thickness dimensions t3 and t4 of the portions 7 and 9 and the thickness dimensions t1 and t2 of the side wall portions 8 and 10 are equal (see FIG. 4), but the thickness dimensions t5 of the corner portions 16 and 17 are required. , T6 may be positively larger than the thickness dimensions t1 and t2 of the side wall portions 8 and 10. FIG. 11 shows an enlarged cross-sectional view of a main part of the thin-walled portion 2 of the die-cast product 1 according to an example thereof (third embodiment of the present invention). As shown in the figure, in the die-cast product 1 according to the present embodiment, the thickness dimensions t5 and t6 of at least some of the corner portions 16 and 17 are larger than the thickness dimensions t1 and t2 of the side wall portions 8 and 10. Specifically, the thickness dimensions t5 and t6 of the corner portions 16 and 17 are set to 1.5 or more, preferably 2.0 or more, in comparison with the thickness dimensions t1 and t2 of the side wall portions 8 and 10, respectively. Set. In FIG. 11, in the corner portion 16 of the convex portion 5, the radius of curvature of the inner R surface thereof is made the same as or larger than the radius of curvature of the outer R surface, and in the corner portion 17 of the concave portion 6, the inner R surface thereof is formed. The radius of curvature of the surface is made the same as or larger than the radius of curvature of the outer R surface.

As described above, by forming the corner portions 16 and 17 between at least a part of the vertical wall portions 7 and 9 and the horizontal wall portions 8 and 10 thicker than the horizontal wall portions 8 and 10, the corner portions 16 and 17 can be formed from various directions. It is possible to further increase the rigidity of the thin-walled portion 2 with respect to a load. Further, since only a part of the wall portion (corner portions 16 and 17) is formed to be thick, there is no concern that the weight reduction of the die-cast product 1 as a whole is hindered. From the above, the die-cast product 1 according to the present embodiment can further improve the rigidity efficiency. Further, in the case of the die-cast product 1, it is relatively easy to partially change the wall thickness as described above depending on the shape setting of the cavity 56, and the vertical wall portions 7 and 9 and the horizontal wall portions where the flow direction of the molten metal changes. By making the corners 16 and 17 between 8 and 10 thick, it is possible to improve the flowability of hot water during casting. Therefore, it is possible to secure the casting quality of the die-cast product 1 while trying to reduce the thickness of the die-cast product 1 as a whole.

In the above embodiment, when only the vertical wall portions 7 and 9 are formed thicker than the horizontal wall portions 8 and 10 (see FIG. 10), only the corner portions 16 and 17 are formed thicker than the horizontal wall portions 8 and 10. Although the case of forming the wall thickness is illustrated, of course, both the vertical wall portions 7 and 9 and the corner portions 16 and 17 may be formed to be thicker than the horizontal wall portions 8 and 10. FIG. 12 shows an enlarged cross-sectional view of a main part of the thin-walled portion 2 of the die-cast product 1 according to an example thereof (fourth embodiment of the present invention). As shown in the figure, in the die-cast product 1 according to the present embodiment, the thickness dimensions t3 and t4 of at least a part of the vertical wall portions 7 and 9 are larger than the thickness dimensions t1 and t2 of the horizontal wall portions 8 and 10. Also. The thickness dimensions t5 and t6 of at least some of the corner portions 16 and 17 are larger than the thickness dimensions t1 and t2 of the side wall portions 8 and 10. In this case, for example, the thickness dimensions t3 and t4 of the vertical wall portions 7 and 9 and the thickness dimensions t5 and t6 of the corner portions 16 and 17 can be set to the same size.

Further, in the above description, the high rigidity pattern 12 is set as the minimum unit of the uneven pattern 11 in which the convex portion 5 and the concave portion 6 are arranged in parallel in each of the regions S11 and S12 obtained by dividing the square region S1 into two. Alternatively, the inverted pattern 13, the same posture pattern 14, or the rotation pattern 15 having the high rigidity pattern 12 as a constituent unit has been exemplified, but the present invention is not limited to this, of course. A plurality of protrusions so that one or more of the vertical wall portions 7 and 9 of the convex portion 5 and the horizontal wall portions 8 and 10 of the concave portion 6 appear on an arbitrary virtual cross section for cutting the thin portion 2 in the front and back directions. As long as the portion 5 and the plurality of recesses 6 are arranged in a predetermined pattern, the concave-convex pattern 11 can take any form, that is, a form other than that shown in FIG.

Further, in the above description, the case where the convex portion 5 and the concave portion 6 are arranged in a predetermined pattern on the thin-walled portion 2 having a flat plate shape and a disk shape is illustrated, but of course, the form of the thin-walled portion 2 is not applicable to this. Not limited. For example, although not shown, the uneven shape according to the present invention may be applied to the thin wall portion having a curved surface shape and a disk shape, or the unevenness according to the present invention may be applied to the thin wall portion having a flat plate shape and a rectangular shape. Shapes may be applied.

1 Die-cast product 2 Thin-walled part 3 Cylindrical part 4 Flange part 5 Convex part 6 Concave part 7, 9 Vertical wall part 8, 10 Horizontal wall part 11, 11a to 11d Concavo-convex pattern 12, 12a to 12g High rigidity pattern 13 Inversion pattern 14 Same posture Pattern 15 Rotation pattern 16, 17 Square 50 Casting device 51 Fixed platen 52 Movable platen 53 Intermediate mold 54 Fixed mold 55 Movable mold 56 Cavity 57 Injection gate 58 Injection sleeve 59 Plunger S1, S2, S3 Square area S11 , S12, S21 to S24, S31 to S34 Divided area t1 to t6 Thickness dimension X Neutral axis

Claims (3)

It is a die-cast product that has at least a thin part.
The thin-walled portion is provided with a convex portion protruding on one side of the front and back and a concave portion protruding in the opposite direction to the convex portion.
A plurality of the convex portions so that a vertical wall portion extending in the vertical direction of the convex portion and a vertical wall portion extending in the vertical direction of the concave portion appear on an arbitrary virtual cross section for cutting the thin wall portion in the front and back directions. The portions and the plurality of recesses are arranged in a predetermined pattern , and
A die-cast product characterized in that the thickness dimension of at least a part of the vertical wall portion is larger than the thickness dimension of the horizontal wall portion connected to the vertical wall portion. The die-cast product according to claim 1, wherein the convex portion is a convex cross-section hat portion having a cross-section hat shape, and the concave portion is a concave cross-section hat portion having a cross-section hat shape. Thickness of the corner portions between the horizontal wall portion and at least a portion of the vertical wall portion, the die cast product according to claim 1 greater than the thickness of the lateral wall portion.

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