JP2007190599A - Die, die for casting aluminum wheel, and method for producing cast aluminum wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the strength of a joined surface where molten metals flow in different flow passages and join together in a cavity. <P>SOLUTION: In a die, at the vicinity of the joining part 9 where the molten metals join, flow rate resistance parts 12a-12d for changing the flow rates of the molten metals are arranged. The flow rates of the molten metal passing through the flow rate resistance parts 12a-12d are slower than those passing through areas where the flow rate resistance parts 12a-12d are not arranged. The flow rate resistance parts 12a, 12b are arranged at the positions where the flow rates of the molten metals flowing in the flow passages of one side before the joining are reduced, and the flow rate resistance parts 12c, 12d are arranged at the positions where the flow rates of the molten metals flowing in the flow passage of the other side before joining are reduced. The flow rate resistance parts 12a, 12b and the flow rate resistance parts 12c, 12d are arranged at different areas in the width direction A respectively. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a mold, and more particularly, to a mold used for casting an aluminum wheel and the like and a technique for manufacturing a cast aluminum wheel using the mold.

In recent years, aluminum alloy wheels for the purpose of improving design have become widespread. The aluminum wheel includes an annular rim, a hub formed at the center of the rim, and spokes that connect the rim and the hub. A mold is used for casting the aluminum wheel, and a cast aluminum wheel is manufactured by injecting molten metal into a cavity formed by the inner wall of the mold, performing heat treatment, and cutting to fit the tire. For example, Patent Document 1 discloses a structure in which a recess for spraying a cooling medium is provided at an intersection between a spoke portion and a rim portion of an aluminum wheel casting mold.
JP 7-284901 A

  In the aluminum wheel casting process, molten metal is injected into the cavity from an injection port (gate portion) provided in the center. The injected molten metal is divided into a plurality of spoke parts and flows through the cavity, and fills the rim part. At this time, the molten metal that has flowed through the adjacent spoke portions merges and joins at the rim portion.

  When molten metal that has flowed through different spoke portions in the cavity joins, a hot water boundary is likely to occur at the joint, and when a hot water boundary occurs, the strength of the molded product at that portion decreases. Since the flow velocity of the molten metal flowing from each spoke portion to the rim portion is substantially the same in the width direction of the rim portion, the joining surface at the joining portion is flat (linear when viewed from the outer surface of the molded product). The hot water boundary portion having a flat joint surface has a problem that the strength against a force in the shear direction is particularly weak.

  This invention is made | formed in view of such a subject, The objective is to provide the technique which improves the intensity | strength in the hot water boundary part of an aluminum wheel. It is another object of the present invention to provide a technique for improving the strength at the joining portion of the molding material when producing a molded product obtained by molding a resin material or the like as well as a cast product such as an aluminum wheel.

  In order to solve the above-described problem, an aspect of the present invention provides a mold in which, when molten metal is injected from an injection port, molten metal that has flowed through different flow paths merges to form a hot water boundary. In the mold according to the aspect, the flow velocity resistance portion that changes the flow velocity of the molten metal is provided in the vicinity of the merge portion where the molten metal merges.

  According to this aspect, by providing the flow velocity resistance portion in the vicinity of the joining portion of the molten metal, the joining surface of the molten metal that has passed through different flow paths can be formed in a non-flat shape. Thereby, the junction area of a junction part can be increased and the intensity | strength of a junction part can be raised. In addition, the molten metal from which the melt from the flow path different from the vicinity of the merged part is integrated and the flow velocity is changed by the flow velocity resistance unit is different from the molten metal whose flow velocity is not changed. ) Includes a position where the influence of the flow velocity change can be maintained.

  The flow velocity of the molten metal that passes through the flow velocity resistance portion may be slower than the flow velocity of the molten metal that passes through a region where the flow velocity resistance portion is not provided. By forming the flow velocity resistance portion as a structure that decelerates the flow velocity of the molten metal, the flow velocity change of the molten metal may be easily realized. The flow velocity resistance part may be an uneven part formed on the inner wall of the mold. It is preferable to set the concavo-convex portion in a direction or position where the undercut does not occur in consideration of the dividing direction. For example, undercuts can be avoided by forming irregularities parallel to the horizontal punching direction on the inner wall of a horizontal mold (horizontal mold). At this time, by increasing the number of horizontal molds constituting the cavity, it is possible to align the direction perpendicular to the flow velocity and the horizontal mold drawing direction.

  The flow velocity resistance portion may be provided in a partial region in the width direction of the cavity orthogonal to the traveling direction of the molten metal. The partial region in the width direction means a band-shaped region that is determined by the distance from one end of the cavity width and extends in the traveling direction. By providing the flow velocity resistance portion in a partial region in the cavity width direction, the flow velocity in that region can be changed. The flow velocity resistance portion is preferably provided in different regions in the width direction of the cavity. By providing a plurality of flow velocity resistance portions in different regions, the flow velocity in each region can be changed.

  The plurality of flow velocity resistance portions may be provided at intervals in the width direction of the cavity at a position where the flow velocity of the molten metal flowing through one flow path is lowered before the molten metals merge. By arranging the flow velocity resistance portion on the one flow path before the joining surface of the molten metal, that is, before the joining surface, the molten metal speed in the flow path can be reduced. Furthermore, by disposing the gaps in the cavity width direction, it is possible to realize a flow velocity distribution in which the flow velocity is different between the region where the flow velocity resistance portion is provided and the region where the flow velocity resistance portion is not provided.

  The plurality of flow velocity resistance portions are provided at a position where the flow velocity of the molten metal flowing through one flow path is reduced before the molten metal merges, and at a position where the flow velocity of the molten metal flowing through the other flow path is reduced, and provided on one flow path side. The region in the cavity width direction of the flow velocity resistance portion provided may not overlap the region in the cavity width direction of the flow velocity resistance portion provided on the other flow path side. In each of the two flow paths, by arranging the flow velocity resistance portion in front of the melt joining surface, that is, the joining surface, the melt speed on the respective flow paths can be reduced. Furthermore, the area | region of the cavity width direction which provides a flow-velocity resistance part is shifted mutually, The area | region where the molten metal speed in one flow path decelerates and the molten metal speed in the other flow path does not decelerate can be created.

  The flow velocity resistance part may be arranged in the width direction of the cavity so that the hot water boundary part has a wavefront shape. Thereby, the joining area in a hot water boundary part can be increased, and intensity | strength can be increased.

  Another aspect of the present invention is an aluminum wheel casting mold. The aluminum wheel casting mold of this aspect has a cavity having a plurality of spoke portions and a rim portion corresponding to the shape of the aluminum wheel, and when molten metal is injected from the injection port, the molten metal that has flowed through the spoke portion enters the rim portion. And a flow velocity resistance portion that changes the flow velocity of the molten metal is provided in the vicinity of the merge portion where the molten metal merges.

  According to this aspect, by providing the flow velocity resistance portion in the vicinity of the melt joining portion in the rim portion, the joining surface of the melt that has passed through the different spoke portions can be formed in a non-flat shape. Thereby, the junction area of a junction part can be increased and the intensity | strength of a junction part can be raised. When a cast aluminum wheel is manufactured using the aluminum wheel casting mold of this aspect, a cast aluminum wheel with improved joint strength can be manufactured.

  Yet another embodiment of the present invention is a mold. This mold is a mold in which liquid material that flows through different flow paths in the cavity merges when liquid material is injected from the injection port, and the flow rate of the liquid material changes near the junction where the liquid material merges A flow velocity resistance unit is provided.

  According to this aspect, by providing the flow velocity resistance portion in the vicinity of the merging portion of the liquid material, the joining surface of the liquid material that has passed through the different flow paths can be formed in a non-flat shape. Thereby, the junction area of a junction part can be increased and the intensity | strength of a junction part can be raised. The liquid material may be a molding material such as a melted metal or a synthetic resin material.

  ADVANTAGE OF THE INVENTION According to this invention, the technique which a molding material can join suitably in the junction part in a cavity can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows a mold according to an embodiment of the present invention. The mold 1 according to the present embodiment includes a lower mold 2, a horizontal mold 3 and an upper mold 4 to form a cavity 10. The lower die 2 is a fixed die having a vertical molten metal passage at the center, the upper die 4 is a movable die that is vertically moved with respect to the lower die 2, and the horizontal die 3 is an upper die 4. The slide core is slidably mounted in the horizontal direction. Although not shown, the injection sleeve is attached to the injection port 7 with the distal end inserted, and a molten metal such as an aluminum alloy is pushed up the injection sleeve 7 through the injection sleeve by the injection plunger.

  The cavity 10 is formed with a spoke portion 5 corresponding to the spoke of the aluminum wheel and a rim portion 6 corresponding to the rim. The spoke portion 5 is provided so as to connect the central portion 8 into which the molten metal is injected and the annular rim portion 6. A plurality of spoke portions 5 extend from the central portion 8 toward the rim portion 6.

  The molten metal injected into the central portion 8 branches and flows into the plurality of spoke portions 5. When the molten metal reaches the annular rim part 6 from the spoke part 5, the molten metal also branches and advances along the annular shape of the rim part 6, and merges with the molten metal that has flowed through the different spoke parts 5.

  FIG. 2 schematically shows the traveling direction of the molten metal in the cavity 10. In the figure, the arrow represents the molten metal flow direction (traveling direction). Although the four spoke portions 5a, 5b, 5c, and 5d are formed in the cavity 10, the number of the spoke portions 5 is not intended to be limited to four, and may be other numbers. The molten metal injected into the central portion 8 flows equally to the spoke portions 5a, 5b, 5c, and 5d. When the molten metal flowing through each spoke part 5 reaches the rim part 6, it branches in two directions according to the circumferential shape of the rim part 6. Thereby, in the rim | limb part 6, the molten metal which flows from the spoke part 5 which adjoins merges, and is integrated. Since the cavity 10 of the present embodiment forms four spoke portions 5a, 5b, 5c, and 5d, the molten metal merges at the four junction portions 9a, 9b, 9d, and 9d. Hereinafter, the merging portions 9a, 9b, 9d, and 9d are collectively referred to as “merging portion 9”.

  FIG. 3 shows a conventional example of a joint surface in a cast aluminum wheel generated at the junction. The joint surface 11a is generated when a casting process is performed using a conventional mold, and is formed flat as illustrated. This is because the flow velocities until reaching the junction 9 through each spoke are equal in the width direction of the cavity. As a result, the joint surface 11a constitutes a hot water boundary portion in the cast aluminum wheel. However, the hot water boundary portion formed in a flat shape has a problem that strength against a force in a shearing direction is particularly weak.

  Therefore, in the mold 1 of the present embodiment, the joining surface generated in the joining portion 9 is not made flat, but, for example, a wavy surface is formed to increase the joining area and increase the strength at the joining surface.

  FIG. 4 shows an example of a joint surface in a cast aluminum wheel according to an embodiment of the present invention. The joint surface 11b is formed in a waved wave surface by performing a casting process using the mold 1 of the present embodiment. The joining surface 11b may constitute a hot water boundary portion, but the hot water boundary portion formed in a wave front shape has a larger bonding area than the hot water boundary portion formed in a flat shape. Therefore, higher strength than that of the joint surface 11a shown in FIG.

  The joining surface 11 a shown in FIG. 4 is formed by changing the flow rate of the molten metal flowing through the rim portion 6 in the width direction A of the cavity 10. In addition, the width direction A of the cavity 10 is a direction orthogonal to the progress (molten metal flow) direction B of the molten metal, and the molten metal travels in the width direction A. Specifically, the width direction A is the rim width direction, and the traveling direction B is the circumferential direction of the rim portion 6. In FIG. 4, a long thick arrow indicates that the flow velocity is relatively fast, and a short thick arrow indicates that the flow velocity is relatively slow. Note that the bonding area may be further increased by changing the flow velocity in the thickness direction C of the cavity 10.

  In the cavity 10 of the present embodiment, a flow velocity resistance portion that changes the flow velocity of the molten metal is provided in the vicinity of the merge portion 9. The flow velocity resistance portion acts as a resistance against the flowing molten metal, and thus has a function of decelerating the molten metal. As shown below, the flow velocity resistance portion is formed, for example, as a concavo-convex structure, and this concavo-convex structure is molded in the vicinity of the junction 9 of the cast aluminum wheel. However, in FIG. .

  FIG. 5 shows an example of the flow velocity resistance portion provided in the cavity 10. The flow velocity resistance portion 12 is configured to have a protruding portion protruding into the flow path, and has a structure of an uneven portion as a whole. The rim portion 6 is defined by the inner walls of the horizontal die 3 and the upper die 4, but the flow velocity resistance portion 12 may be provided on either the horizontal die 3 or the upper die 4, or may be provided on both. The structure of the flow velocity resistance unit 12 is not limited to the concavo-convex structure, and may take other structures. Further, the flow velocity resistance unit 12 may change the viscosity by changing the molten metal temperature to change the flow velocity, and may have a function of changing the flow velocity even when any structure is adopted. .

  FIG. 6 shows an example of the arrangement of the flow velocity resistance portions 12 formed on the upper mold 4. In this example, two flow velocity resistance portions 12 a and 12 b are formed on the upper mold 4. The flow velocity resistance parts 12a and 12b are provided in a partial region in the width direction A in the flow path to the joint surface 11b. The region in the flow path is a band-shaped region that is specified by a distance from one end of the width of the cavity 10 and extends in the traveling direction.

  The flow velocity of the molten metal that passes through the flow velocity resistance portions 12a and 12b is slower than the flow velocity of the molten metal that passes through the region where the flow velocity resistance portions 12a and 12b are not provided. Therefore, the molten metal flowing in the flow path from the left side toward the joint surface 11b in the drawing has a flow velocity distribution in which the molten metal flow speed changes in the width direction A. This is because the flow velocity resistance parts 12a and 12b are arranged only in a part of the width direction A in the flow path. Further, the plurality of flow velocity resistance portions 12a and 12b are arranged in different regions in the width direction A. Thereby, the molten metal can be decelerated in a plurality of regions in the width direction A. On the other hand, the molten metal flowing toward the joint surface 11b from the right side in the drawing does not have the flow velocity resistance portion 12 in the flow path, so the flow velocity distribution in the width direction A is substantially constant and does not change.

  In the example of FIG. 6, the plurality of flow velocity resistance portions 12 a and 12 b are spaced apart from each other in the width direction A at a position where the flow velocity of the molten metal flowing through the flow path from the left side to the joint surface 11 b is decreased before the molten metal merges. Opened. As a result, the flow velocity in the plurality of regions, that is, the regions where the flow velocity resistance portions 12a and 12b are provided can be reduced, and therefore the wavefront joint surface 11b can be formed. The wavefront joining surface 11b has an advantage that the strength against the shearing force is high because the joining area is larger than that of the flat joining surface 11a. Thereby, even if it is a case where the joint surface 11b becomes a hot water boundary part, high intensity | strength can be shown.

  FIG. 7 shows another example of the arrangement of the flow velocity resistance portions 12 formed in the upper mold 4. In this example, four flow velocity resistance portions 12a, 12b, 12c and 12d are formed in the upper mold 4. The flow velocity resistance portions 12a and 12b are provided at positions where the flow velocity of the molten metal flowing through the flow path from the left side in the drawing to the joint surface 11b is lowered before the molten metal merges. Further, the flow velocity resistance portions 12c and 12d are provided at positions where the flow velocity of the molten metal flowing through the flow path from the right side in the drawing to the joint surface 11b is lowered before the molten metal merges.

  In the flow path from the left side toward the joint surface 11b in the drawing, the flow rate of the molten metal that passes through the flow velocity resistance parts 12a and 12b is slower than the flow rate of the molten metal that passes through the region where the flow velocity resistance parts 12a and 12b are not provided. Therefore, the molten metal flowing through the left channel has a flow velocity distribution in which the molten metal flow speed changes in the width direction A. Similarly, in the flow path from the right side to the joint surface 11b in the drawing, the flow rate of the molten metal that passes through the flow velocity resistance parts 12c and 12d is higher than the flow rate of the molten metal that passes through the region where the flow velocity resistance parts 12c and 12d are not provided. Become slow. Therefore, the molten metal flowing through the right channel has a flow velocity distribution in which the molten metal flow speed changes in the width direction A.

  Further, the flow velocity resistance portions 12a and 12b provided in the left flow channel and the flow velocity resistance portions 12c and 12d provided in the right flow channel are shifted so as not to overlap each other in the width direction A. Thereby, the flow path for decelerating the flow velocity is alternately arranged in the width direction A, and the amplitude of the wavefront can be made larger than that of the joint surface 11b shown in FIG. Therefore, the bonding area can be further increased, and the strength against the shearing force can be further increased.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  For example, in the embodiment, the mold 1 for casting an aluminum wheel has been described. However, the cast product is not limited to an aluminum wheel, and the present invention can be used for a mold of another cast product. Moreover, although the Example demonstrated the metal mold | die 1 for casting using the molten metal which melted the metal, not only a cast product but the metal mold | die for molded products shape | molded with resin materials etc. can utilize this invention. Can do.

It is a figure which shows the metal mold | die concerning the Example of this invention. The advancing direction of the molten metal in a cavity is shown typically. It is a figure which shows the prior art example of the joint surface in a cast aluminum wheel. It is a figure which shows an example of the joint surface in the cast aluminum wheel concerning the Example of this invention. It is a figure which shows an example of the flow-velocity resistance part provided in a cavity. It is a figure which shows an example of arrangement | positioning of the flow velocity resistance part formed in the upper mold | type. It is a figure which shows another example of arrangement | positioning of the flow velocity resistance part formed in the upper mold | type.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mold, 2 ... Lower mold, 3 ... Horizontal type, 4 ... Upper mold, 5 ... Spoke part, 6 ... Rim part, 7 ... Injection port, 8 .. Central part, 9 ... Merging part, 10 ... Cavity, 11 ... Joint surface, 12 ... Velocity resistance part.

Claims (11)

When the molten metal is injected from the inlet, the molten metal that flows through different flow paths in the cavity merges to form a hot water boundary,
A mold characterized in that a flow velocity resistance portion for changing the flow velocity of the molten metal is provided in the vicinity of the merge portion where the molten metal merges.   The mold according to claim 1, wherein the flow velocity of the molten metal that passes through the flow velocity resistance portion is slower than the flow velocity of the molten metal that passes through a region where the flow velocity resistance portion is not provided.   The mold according to claim 1 or 2, wherein the flow velocity resistance portion is provided in a partial region in the width direction of the cavity orthogonal to the traveling direction of the molten metal.   The mold according to any one of claims 1 to 3, wherein the flow velocity resistance portion is provided in different regions in the width direction of the cavity.   The flow velocity resistance portion is provided at a position where the flow velocity of the molten metal flowing through one flow path is lowered before the molten metal merges, and is spaced from each other in the width direction of the cavity. Mold as described in Crab.   The flow velocity resistance portion is provided at a position where the flow velocity of the molten metal flowing through one flow path is reduced before the molten metal merges and a position where the flow velocity of the molten metal flowing through the other flow path is reduced, and is provided on one flow path side. 5. The gold according to claim 1, wherein a region in the cavity width direction of the flow velocity resistance portion and a region in the cavity width direction of the flow velocity resistance portion provided on the other flow path side do not overlap each other. Type.   The mold according to any one of claims 1 to 6, wherein the flow velocity resistance portion is arranged in the width direction of the cavity so that the hot water boundary portion has a wavefront shape.   The mold according to any one of claims 1 to 7, wherein the flow velocity resistance part is an uneven part formed on an inner wall of the mold. This is an aluminum wheel casting mold that has a cavity with a plurality of spoke parts and rim parts corresponding to the shape of the aluminum wheel, and when molten metal is injected from the inlet, the molten metal that flows through the spoke parts merges at the rim part. And
A mold for casting an aluminum wheel, characterized in that a flow velocity resistance portion for changing a flow velocity of the molten metal is provided in the vicinity of a merge portion where the molten metal merges.   A method for producing a cast aluminum wheel using the mold for casting an aluminum wheel according to claim 9. When the liquid material is injected from the injection port, the liquid material that has flowed through different flow paths in the cavity merges,
A mold characterized in that a flow velocity resistance portion for changing the flow velocity of the liquid material is provided in the vicinity of the merge portion where the liquid material merges.

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