JP5798380B2 - Mold for vehicle wheel manufacturing - Google Patents

Description

  The present invention relates to a mold for manufacturing a vehicle wheel.

  When manufacturing a vehicle wheel, the low pressure casting method is widely used. The low pressure casting method pressurizes the interface of the molten metal held in the holding furnace (chamber), pushes the molten metal up in the hot water supply pipe (Stoke), flows into the mold cavity, and cools the molten metal in the cavity. It is a method to solidify. At this time, the molten metal is cooled by radiating heat from the wall surface of the mold cavity.

  Generally, a vehicle wheel has a different thickness (wall thickness) for each part such as a rim, a hub, or a spoke. Here, as described above, since the molten metal is cooled by heat radiation from the wall surface of the cavity, the cavity having a distance to the wall surface is formed at a portion where the thick portion (thick portion) of the vehicle wheel is formed. It takes time to cool down to the center. When the solidification rate of the molten metal is thus slowed, shrinkage cavities and the like are likely to occur.

  Therefore, a mold for manufacturing a vehicle wheel assembled from members having different thermal conductivities has been devised. In the mold that has been devised, the wall surface of the cavity is formed of a member having high thermal conductivity at a location where the thick portion of the vehicle wheel is formed in the cavity. Due to the action of the wall surface with high thermal conductivity, the molten metal is easily cooled locally, and the solidification rate of the molten metal is increased (for example, Patent Documents 1 and 2). As a result, the time difference until the molten metal solidifies between the thick part and the thin part (thin part) of the vehicle wheel is reduced, and the occurrence of casting defects such as shrinkage cavities is suppressed. Can do.

Japanese Unexamined Patent Publication No. 4-197550 JP 2001-71095 A

  However, when a mold is assembled from members having different thermal conductivities such as the above-described mold for manufacturing a vehicle wheel, the wall surface of the cavity is localized due to reaction of any of these members with the molten metal. Cause melting, chipping, corrosion, etc. As a result, it is difficult to repeat casting.

  In view of the above problems, an object of the present invention is to provide a mold for manufacturing a vehicle wheel that can locally increase the solidification rate of a molten metal and can be used repeatedly.

  The object described above can be achieved according to the present invention. Specifically, it is a mold for manufacturing a vehicle wheel described below.

[1] A disk molding portion that includes a cavity for filling a molten metal and a molten metal flow path for injecting the molten metal into the cavity, and the cavity expands radially outward from the center of the cavity. And a rim molding part extending from the outer peripheral edge of the disk molding part, and the member that forms a part of the wall surface of the cavity has a higher thermal conductivity than the member that forms the other part of the wall surface of the cavity. The heat radiating member includes a high material, and the heat radiating member is movably provided toward the inside of the cavity. The disk molding portion includes a hub molding portion in a central portion and the hub molding. A plurality of spoke molded portions that radiate from the portion and extend toward the outer peripheral edge of the disk molded portion, and the heat dissipation member is positioned in a direction in which the spoke molded portion extends. And a mold for manufacturing a vehicle wheel , wherein a part of the wall surface of the cavity is formed at a portion where the outer peripheral edge of the disk forming portion and the rim forming portion intersect .

[2] have a fixing means for fixing the position of the heat radiating member, said fixing means comprises a movable connecting portion toward said inside cavity together with the heat radiating member while connected to the heat radiating member, the connecting portion And a support part that connects and displaces the connection part in a direction toward the inside of the cavity, and the connection part and the support part are provided with either a screw member or a screw hole. converting mechanism linked together by screwing, the displacement and positioning in the direction towards the cavity inside the connecting portion, according to the said to have been made by a screw mechanism by the screw member and the screw holes [1] Mold for vehicle wheel manufacturing.

  The mold for manufacturing a vehicle wheel according to the present invention can locally increase the solidification rate of the molten metal and can be used repeatedly.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a vehicle wheel manufacturing mold according to an embodiment of the present invention and a low-pressure casting apparatus including the same. It is a top view of the wheel for vehicles, and is a figure for demonstrating the positional relationship of the wheel for vehicles and a heat radiating member. It is an enlarged view in the frame A in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the following embodiments, and changes, modifications, and improvements can be added without departing from the scope of the present invention.

  A vehicle wheel manufacturing mold of the present invention (hereinafter referred to as “mold of the present invention”) includes a cavity for filling a molten metal and a molten metal flow path for injecting the molten metal into the cavity. . This cavity has a disk molding part and a rim molding part. The disk molding portion extends from the center of the cavity toward the outside in the radial direction. When the molten metal filled in the disk forming portion is solidified, the disk portion of the vehicle wheel is formed. The rim molding part extends from the outer peripheral edge of the disk molding part. When the molten metal filled in the rim forming portion is solidified, a rim portion of the vehicle wheel is formed.

  Furthermore, in the mold of the present invention, the member that forms part of the wall surface of the cavity is a heat radiating member that includes a material having a higher thermal conductivity than the member that forms the other part of the wall surface of the cavity. Since the wall surface of the cavity formed by the heat radiating member has high thermal conductivity, it is easy to radiate the heat of the molten metal. That is, the molten metal in contact with the wall surface of the cavity formed by the heat radiating member is more easily cooled than the molten metal in other portions in the cavity, and as a result, the solidification rate is increased.

  The vehicle wheel usually has a different thickness for each part, and it takes time for the thick part to complete solidification of the molten metal. Here, when the wall surface of the cavity is formed by the heat radiating member at the location where the thick part of the vehicle wheel is formed, the molten metal can be quickly cooled locally at this location. The coagulation rate can be increased. As a result, the molten metal can be easily solidified uniformly, and the occurrence of casting defects such as shrinkage cavities in the resulting vehicle wheel can be suppressed.

  In the mold of the present invention, the heat dissipating member contains any one of copper, copper nickel alloy and the like as a main component, and the member forming the cavity other than the heat dissipating member is copper, copper nickel alloy, etc. Cast iron, mold alloys (SKD, SCM, etc.), general steel materials, etc. with lower thermal conductivity are desirable.

  Moreover, in the casting_mold | template of this invention, the heat radiating member is provided so that the movement toward the inside of a cavity is possible. Thus, when the heat radiating member can move inside the cavity, even if the wall surface of the cavity formed by the heat radiating member is melted, it can be easily repaired. That is, the heat radiating member is moved toward the inside of the cavity to protrude into the cavity, and the protruded portion can be cut to process the wall surface to the original shape. Since the cavity wall surface can be easily repaired in this way, the mold of the present invention can be used repeatedly without much trouble.

  For example, in the mold of the present invention, when the heat dissipating member is made of copper and the molten metal is made of aluminum, the wall surface of the cavity formed from the heat dissipating member is melted by the reaction between copper and aluminum. End up. Thus, even if the wall surface of the cavity is melted or the like, it can be restored to a normal mold by performing the above-described processing on the heat radiating member.

  In the mold of the present invention, when the disk molding part has a hub molding part in the center part and a plurality of spoke molding parts that radially diverge from the hub molding part and extend toward the outer peripheral edge of the disk molding part. Preferably, the heat dissipating member forms a part of the wall surface of the cavity at a portion where the outer peripheral edge of the disk forming portion and the rim forming portion intersect with each other, located in the direction in which the spoke forming portion extends. The portion where the outer periphery of the disk forming portion and the rim forming portion intersect, particularly the portion located in the direction in which the spoke forming portion extends, has a larger cavity width (also referred to as “thickness” of the cavity) than the other portions. Therefore, the molten metal is difficult to be cooled and eventually solidified. When a part of the wall surface of the cavity in this part is formed from a heat radiating member, cooling of the molten metal can be promoted and the solidification rate can be increased by the principle as described above.

  Further, the mold of the present invention preferably has a fixing means for fixing the position of the heat radiating member from the viewpoint that the shape of the cavity can be satisfactorily maintained.

  Further, the fixing means used in the mold of the present invention includes a connection portion that is movable toward the inside of the cavity together with the heat dissipation member while being connected to the heat dissipation member, and is connected to the connection portion in a direction toward the inside of the cavity with respect to the connection portion. It is preferable to have a support part that performs the displacement and positioning of these. Thus, when the displacement and positioning of the heat radiating member toward the inside of the cavity are controlled by the fixing means, the heat radiating member can be positioned more accurately. Further, by providing the fixing means with a mechanism for positioning the heat radiating member, the heat radiating member can be easily formed into a shape suitable for heat radiating, and as a result, the solidification rate of the molten metal can be more reliably increased by the heat radiating member. .

  In the case where the fixing means used in the mold of the present invention has the connecting portion and the supporting portion as described above, from the viewpoint that the moving amount of the heat dissipation member can be appropriately adjusted, the connecting portion and the supporting portion are: Either one of the screw member and the screw hole is provided and screwed together to be connected to each other, and the displacement and positioning in the direction toward the inside of the cavity of the connecting portion are performed by a screw mechanism by the screw member and the screw hole. Preferably it is.

  Hereinafter, the content will be described in detail with reference to a specific embodiment of a mold for manufacturing a vehicle wheel of the present invention.

  FIG. 1 is a cross-sectional view of a mold for manufacturing a vehicle wheel according to an embodiment of the present invention and a low-pressure casting apparatus including the same. As shown in the figure, the low pressure casting apparatus D includes a mold set S and a base 10 on which the mold set S is placed.

  The main members of the mold set S are three types of molds: a lower mold 20, an upper mold 40, and a pair of horizontal molds 30. When these molds are combined to form a mold set S, a cavity 50 is formed inside. The cavity 50 is a cavity having substantially the same shape as the vehicle wheel. In this mold set S, the cavity 50 is composed of a disk molding part 51 and a rim molding part 53. Further, in the present mold set S, the disk forming portion 51 has a hub forming portion 55 at the center and a spoke forming portion 57 that branches radially from the hub forming portion 55. From the disk forming portion 51, the rim forming portion 53, the hub forming portion 55, and the spoke forming portion 57, portions corresponding to the disc, rim, hub, and spoke in the vehicle wheel can be formed. By filling the molten metal in the cavity 50 of the mold set S and solidifying it, a casting for a vehicle wheel can be formed.

  FIG. 2 is a front view of a specific example of a vehicle wheel that can be manufactured using the mold set S. FIG. The vehicle wheel 80 includes a disk 81 and a rim 82. Further, the disk 81 has a hub 83 in the center portion and a plurality of spokes 84 extending radially from the hub. When the vehicle wheel 80 is manufactured using the mold set S, a cavity having substantially the same shape as the vehicle wheel 80 is formed as the cavity 50 inside the mold set S.

  Further, in the present mold set S, a recess is formed on the lower mold 20, and the insert 21 is fitted in the recess. The disk portion of the vehicle wheel can be formed into a desired uneven shape.

  In the present mold set S, the pair of horizontal molds 30 are separated on a surface including a portion corresponding to the central axis of the vehicle wheel. Each of the mating surfaces of the two horizontal molds 30 has a recess, and when the mating surfaces of the two horizontal molds 30 are mated, a runner 31 is formed. There are one runner 31 on each side of the mold set S, that is, a pair. These runners 31 are substantially L-shaped, and one end of the runner 31 is opened as a side end opening 311 in the rim forming part 53 of the cavity 50, and the other end of the runner 31 is The lower end opening 312 is opened on the lower surface of the horizontal mold 30. Thereby, the molten metal can be caused to flow into the runner 31 from the lower end opening 312, and the molten metal that has flowed into the runner 31 can be injected into the cavity 50 from the side end opening 311. Further, a weir is formed in the side end opening 311 so that the flow path is narrowed.

  Further, in the mold set S, the heat radiating member 41 is inserted through the horizontal mold 30. FIG. 3 is an enlarged view in the frame A in FIG. In this enlarged view, the vicinity of the rim forming portion 53 and the intersecting portion 12 is depicted. In the present specification, the intersecting portion 12 refers to a portion of the outer peripheral edge 17 of the disc forming portion 51 that is located in the extending direction of the spoke forming portion 57 and intersects with the rim forming portion 53. As shown in the figure, in the mold set S, the heat radiation member 41 is inserted and pushed toward the intersection 12. Accordingly, the cavity 50 in the intersecting portion 12 is formed by being surrounded by the wall surface 19 a of the horizontal mold 30, the wall surface 19 b of the upper mold 40, the wall surface 19 c of the lower mold 20, and the wall surface 45 of the heat radiating member 41.

  The intersecting portion 12 has a large volume of the cavity 50, so that more molten metal is accumulated than the other portions. In the present mold set S, a part of the molten metal accumulated in the intersecting portion 12 comes into contact with the wall surface 45 formed by the heat radiating member 41 and is actively radiated from the wall surface 45. That is, in the present mold set S, the molten metal collected at the intersection 12 is easily cooled. Therefore, the solidification speed of the molten metal stored in the intersection 17 can be increased. Thus, the time required for the solidification of the molten metal at the intersecting portion 17 has a small difference from the time required for the solidification of the melt in another thin portion [for example, the central portion of the rim forming portion 53 (the portion where the rim bottom portion is formed)]. Become. Thus, since the difference in solidification time of the solidification of the molten metal becomes small for each part, the obtained vehicle wheel has fewer casting defects such as shrinkage nests.

As shown in FIG. 3, a sheath 65 is joined to the outer peripheral surface 33 of the horizontal mold 30. The sheath portion 65 is provided with a screw hole 67. The screw hole 67 extends _{in the} direction _in which the heat dissipation member 41 is inserted through the horizontal mold 30 (shown as the Xin direction in FIG. 3). The screw part 61 of the stopper 60 is inserted into the screw hole 67. Thus, the screw hole 67 of the sheath portion 65 and the screw portion 61 of the stopper 60 are screwed together, and the position of the stopper 60 is fixed. Furthermore, a head 63 is joined to the stopper 60 at the base of the screw portion 61, and the head 63 is fitted in the recess 43 of the heat radiating member 41. As a result, the position of the heat radiation member 41 is fixed by the stopper 60.

The stopper 60 can move forward and backward along the direction ( _Xin direction) _in which the heat radiating member 41 is inserted into the horizontal mold 30 by operating a screw mechanism including the screw member 61 and the screw hole 67. is there. Further, since the stopper 60 is moved by a screw mechanism, the position of the stopper 60 can be finely adjusted. At this time, the stopper 60 is so advanced also retreats along with the heat radiating member 41 (X _in direction), can also be fine-adjusted for the position of the heat radiating member 41.

For example, after repeated casting, when the wall surface 45 of the heat radiation member 41 is melting and the like, a cavity the front end of the heat radiation member 41 is moved forward the heat dissipation member 41 in the X _in the direction by operating a screw mechanism described above The wall surface 45 of the heat radiating member 41 can be repaired by projecting it into 50 and then separating the horizontal mold 30 and cutting the melted portion of the tip of the heat radiating member 41 into a predetermined shape. At this time, since the forward movement of the heat radiating member 41 can be finely adjusted by the screw mechanism, the protrusion of the tip of the heat radiating member 41 can be suppressed to the minimum. The amount of shaving of the member 41 can be reduced.

  Moreover, according to this mold set S, even when the shape of the wall surface 45 of the heat radiation member 41 is changed due to a slight design change of the vehicle wheel, the wall surface 45 of the heat radiation member 41 can be changed by the above-described method. By changing the shape, it can be dealt with easily.

  In the present mold set S, the heat radiation member 41 includes an insertion portion 47 inserted into the horizontal mold 30 and an exposed portion 49 exposed to the outside. The exposed portion 49 is wider than the insertion portion 47, and the surface area is increased accordingly. By increasing the surface area of the exposed portion 49 in this manner, the heat radiating member 41 can easily dissipate heat, and as a result, the cooling effect of the molten metal is enhanced.

  Although not shown here, when it is desired to cool the molten metal more effectively, it is preferable to provide fins or the like in the exposed portion 49 to increase the surface area and further enhance the heat dissipation effect.

  In the present mold set S, the mechanism for positioning the heat radiating member 41 is not provided only in the heat radiating member 41 but is also shared by the stopper 60 and the sheath portion 65, and thus the shape of the heat radiating member 41 itself is limited. Less. Therefore, in this mold set S, it becomes easy to adopt the shape of the heat radiation member 41 that can enhance the heat radiation effect (particularly, the exposed portion 49 has a shape suitable for heat radiation).

  FIG. 2 is a view for explaining the positional relationship between the vehicle wheel produced using the mold set S and the heat radiating member. As illustrated, the vehicle wheel 80 has six spokes 84 extending radially from the hub 83 toward the outer peripheral edge of the disk 81. A portion where the outer peripheral edge of the disk 81 and the rim 82 intersect with each other is located in a direction in which the spoke 84 extends, and is a thick portion. Therefore, when casting this thick part, the molten metal is difficult to solidify. When casting the vehicle wheel 80 using the mold set S, the wall surface 45 of the heat radiating member 41 is applied to a portion where the outer periphery of the disk 81 and the rim 82 intersect with each other while the spoke 84 is located in the extending direction. Yes. If it carries out like this, it will become possible to accelerate the solidification rate of a molten metal locally in a thick part.

  In FIG. 2, the heat radiating member 41 is applied to four spokes 84 out of the six spokes 84. The reason why the heat radiating member 41 is not applied to the remaining two spokes 84 is that the runner 31 is formed at a position where these spokes 84 extend, and therefore the heat radiating member 41 cannot be applied.

  2 shows a form in which the heat dissipation member 41 is applied in the direction from the outer peripheral side of the vehicle wheel 80 toward the center, but the heat dissipation member 41 is changed depending on the location where the solidification rate of the molten metal is to be increased. You may apply in the direction which goes to the outer peripheral side from the center of this vehicle wheel 80, or may apply in the direction which goes from the surface of this vehicle wheel 80 to a back surface.

  In the low pressure casting apparatus D, a mold set S is placed on the base 10. An intermediate stalk 70 passes through the base 10. The intermediate stalk 70 can be arranged in a state extending in a direction inclined with respect to the vertical direction. The upper end of the intermediate stalk 70 is connected to the lower end opening 312 of the runner 31. Thereby, the molten metal that has flowed into the intermediate stalk 70 can be fed into the runway 31.

  Under the base 10, a molten metal holding furnace 60 is disposed. The molten metal M is accommodated in the molten metal holding furnace 60. A holding furnace stalk 75 is attached to the molten metal holding furnace 60. The holding furnace stalk 75 extends in a substantially vertical direction. The upper end of the holding furnace stalk 75 is connected to the lower end of the intermediate stalk 70, and the lower end of the holding furnace stalk 75 is inserted into the molten metal M accommodated in the molten metal holding furnace 60. In the low pressure casting apparatus D, a filter R is provided between the runway 31 and the intermediate stalk 70 so that foreign matters mixed in the molten metal can be removed.

  In this low pressure casting apparatus D, the molten metal M is fed into the cavity 50 through the stalk (intermediate stalk 70 and holding furnace stalk 75) by supplying gas into the molten metal holding furnace 60 and pressurizing the molten metal M. Can do. After the molten metal M is filled in the cavity 50 and the runner 31 in this way, the molten metal is solidified in the cavity 50 and the runner 31, and then each mold is released to obtain a cast product for a vehicle wheel. obtain. The cast product for the vehicle wheel may be ground to obtain a final shape vehicle wheel by grinding each part to a desired thickness.

  The present invention can be used as a mold for manufacturing a vehicle wheel.

10: Base, 12: Intersection, 17: Outer peripheral edge (of disc forming part), 19a: (Horizontal) wall, 19b: (Upper) wall, 19c: (Lower) wall, 20: Bottom Mold: 21: Nesting, 30: Horizontal type, 31: Runway, 33: (Horizontal type) outer peripheral surface, 40: Upper mold, 41: Heat radiation member, 43: Recessed part (of heat radiation member), 45: (Heat radiation member) Wall: 47: insertion part, 49: exposed part, 50: cavity, 51: disk molding part, 53: rim molding part, 55: hub molding part, 57: spoke molding part, 60: stopper, 61: screw part, 63: head, 65: sheath, 67: screw hole, 70: intermediate stalk, 80: vehicle wheel, 81: disc, 82: rim, 83: hub, 84: spoke, 311: (runner side) End opening, 312: Lower end opening (of runner), D: Low pressure casting apparatus for vehicle wheel M: molten metal, R: filter, S: template set.

Claims (2)

A cavity for filling the molten metal, and a molten metal flow path for injecting the molten metal into the cavity,
The cavity has a disk molding part that expands radially outward from the center of the cavity, and a rim molding part that extends from the outer periphery of the disk molding part,
The member that forms a part of the wall surface of the cavity is a heat dissipation member that includes a material having a higher thermal conductivity than the member that forms the other part of the wall surface of the cavity.
The heat dissipation member is provided to be movable toward the inside of the cavity ,
The disk molding portion includes a hub forming portion in the center, and a plurality of spokes forming portion extending toward branches radially from the hub forming portion in the outer periphery of the disc shaped portion, the heat dissipation The member is located in a direction in which the spoke forming portion extends and forms a part of the wall surface of the cavity at a portion where the outer peripheral edge of the disc forming portion and the rim forming portion intersect . Mold. Have a fixing means for fixing the position of the heat radiating member,
The fixing means is connected to the heat radiating member and connected to the heat radiating member together with the heat radiating member and movable toward the inside of the cavity. And a support part for positioning,
The connection portion and the support portion are connected to each other by being screwed together with any one of a screw member and a screw hole,
The mold for manufacturing a vehicle wheel according to claim 1 , wherein displacement and positioning of the connecting portion in a direction toward the inside of the cavity are performed by a screw mechanism including the screw member and the screw hole .

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