JP2006272344A - Metallic mold for casting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metallic mold for casting with which a thick part of a hub of a vehicle wheel excellent in strength can be obtained in casting of the vehicle wheel. <P>SOLUTION: The metallic mold for use in casting the vehicle wheel is provided with two or more of partial metallic molds and a core and is formed with a cavity inside, wherein the cavity has a gap part for forming the thick part of a shape corresponding to the thick part of the hub of the vehicle wheel. The metallic mold is further provided with a member for cooling the thick part, the member having thermal conductivity higher than that of the partial metallic mold and being arranged inside the partial metallic mold so that a part of the surface of the member (an exposed surface for cooling) is exposed to the gap part for forming the thick part in the cavity and constitutes a part of the inner surface of the partial metallic mold. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a casting mold, and more particularly to a casting mold that can prevent a thick portion of a hub from becoming brittle when a vehicle wheel is cast.

  Conventionally, when casting a vehicle wheel having a hollow hub and spokes extending radially from the hub, for example, a motorcycle wheel (hereinafter, simply referred to as “wheel”), a gravity casting method, a low pressure Using a mold such as a casting method, semi-melt molding method, semi-solid molding method, die casting method, etc., melting in a cavity formed by placing a core corresponding to the desired hollow shape inside the casting mold A metal filling method is used. Specifically, molten metal is poured from the runner of the cavity, the molten metal is poured into the cavity along the outer surface of the core, and the filled molten metal is solidified to obtain a wheel. Can do.

  A disc brake plate is mounted on one surface (disc brake plate mounting surface) of the obtained wheel hub, and when the tire of a motorcycle is rotated, the disc brake plate is sandwiched between disc brake pads. Tire rotation is inhibited or stopped. When the disc brake plate is mounted on the disc brake plate mounting surface, the disc brake plate is fixed by, for example, bolting a screw hole formed in the disc brake plate mounting surface. The screw hole is normally formed in a thick portion (thick portion) provided in the hub. In this case, when the brake is applied, the rotation of the wheel is stopped (or suppressed) at the portion (thick portion) where the screw hole is formed on the disc brake plate mounting surface to which the disc brake plate is fixed. Therefore, it is necessary that the thick portion has a strength that can withstand this force.

  Conventionally, when the molten metal filled in the cavity is cooled and solidified, a casting mold filled with the molten metal is left as it is and naturally cooled (for example, see Patent Document 1).

Japanese Patent No. 3279886

  However, in this method, the thin part is cooled at an appropriate speed and is excellent in strength, but the part formed to be thick like the thick part is fragile because the cooling rate is slow. There was a problem of becoming. Further, in the wheel for a motorcycle, since the hub is at the center, the relationship between the rim width B and the hub width A is (1/3) <(A / B) <2, so it takes time to cool the hub. There has been a problem that the hub is prone to casting defects. Here, the rim width and the hub width are lengths of the rim and the hub in a direction perpendicular to the diameter of the wheel.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to make the thick part of the hub excellent in strength when casting a vehicle wheel. An object of the present invention is to provide a casting mold that can be used.

  In order to achieve the above object, the following casting mold is provided by the present invention.

[1] comprising two or more partial molds and a core that is disposed inside the matched partial molds and defines a cavity by the inner surface and the outer surface of the partial molds A casting mold used for casting a vehicle wheel having a hollow hub and spokes extending radially from the hub by filling the cavity with molten metal and then cooling, A thick part having a shape corresponding to the thick part of the hub so that the cavity has a thick part for forming a screw hole in a part of the wall of the hub after casting. And a part of the surface (exposed surface for cooling) is exposed to the thick part forming cavity of the cavity, and is formed on the inner surface of the partial mold. Said partial mold to constitute the part When the cooling is performed after the molten metal is further filled with the molten metal which is disposed inside, and further has a thick part cooling member having the same thermal conductivity as the partial mold or larger than the partial mold. By making the temperature of the thick part cooling member lower than the temperature of the partial mold, the thick part of the hub with which the exposed surface for cooling comes into contact is substantially the same as the other part of the vehicle wheel. Casting mold that can cool at speed or faster.

[2] The cavity has a hub-forming gap having a shape corresponding to the hub such that the hub after casting has a surface perpendicular to the central axis thereof, and The thick portion forming gap constitutes a part of the hub forming gap, and one surface for forming the screw hole of the thick portion after casting is the cast portion of the hub. The casting mold according to [1], wherein the casting mold has a shape corresponding to the thick portion of the hub so as to constitute a part of the one surface perpendicular to the central axis.

[3] The thick part cooling member includes a tubular refrigerant flow pipe capable of flowing a refrigerant, and the refrigerant flow pipe disposed in the refrigerant flow pipe when the refrigerant flows through the refrigerant flow pipe. A casting mold as set forth in [1] or [2], comprising a thick-walled part cooling rod cooled through the wall.

[4] The material for the thick part cooling member is mainly composed of at least one selected from the group consisting of copper, copper alloy, tungsten alloy, aluminum, aluminum alloy, iron and iron alloy [1]. ] The casting mold according to any one of [3] to [3].

  Thus, according to the casting mold of the present invention, when cooling after filling the cavity with molten metal, the wall thickness cooling member is cooled to a temperature lower than that of the partial mold. Since the thick part of the hub that the exposed surface for cooling of the member contacts is cooled at approximately the same speed or faster than the other parts of the vehicle wheel, a vehicle wheel with excellent strength of the thick part of the hub can be obtained. Obtainable.

  Next, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and is within the scope of the present invention. Based on this knowledge, it should be understood that design changes, improvements, etc. can be made as appropriate.

  FIG. 1 is a sectional view showing an embodiment of a casting mold of the present invention. In FIG. 1, a cavity 11 corresponding to one of the spokes is cut by a plane including an axis corresponding to the central axis (rotary axis) of a motorcycle wheel cast by the casting mold 100 of the present embodiment. As shown, a cross section of the casting mold 100 is shown. 2 (a), FIG. 2 (b), and FIG. 2 (c) show the thick part cooling member disposed in one embodiment of the casting mold of the present invention. ) Is a plan view, FIG. 2B is a front view, and FIG. 2C is a cross-sectional view. FIG. 3 is a plan view showing a two-wheeled vehicle wheel manufactured using an embodiment of the casting mold of the present invention. In the present embodiment, a casting mold for casting a wheel for a motorcycle is described. However, the casting mold of the present invention is not limited to casting a wheel for a motorcycle. It can be used for casting of all vehicle wheels such as wheels for wheels.

  As shown in FIG. 1, a casting mold 100 according to the present embodiment includes two or more partial molds 1 including an upper mold 2, a lower mold 3, and a horizontal mold 4, and a matched partial mold 1. An inner surface 6 of the partial mold 1 and a core 5 that divides the cavity 11 by an outer surface (outer surface of the core) 7 are provided, and the cavity 11 is filled with molten metal. Then, by cooling, a two-wheeled vehicle wheel 31 (see FIG. 3) having a hollow hub 32 (see FIG. 3) and spokes 33 (see FIG. 3) extending radially from the hub 32 (see FIG. 3) is cast. This is a casting mold 100 used for the purpose. In the casting mold 100 of the present embodiment, the cavity 11 has a hub 32 (see FIG. 3) after casting, and a screw hole in a part of the wall (hub wall) 35 (see FIG. 3). 37 (see FIG. 3) corresponds to the thick portion 36 (see FIG. 3) of the hub 32 (see FIG. 3) so as to have a thick portion 36 (see FIG. 3) for forming. The thick portion forming gap 12 has a shape, and part of the surface (exposed surface for cooling) 24 is exposed to the thick portion forming gap 12 of the cavity 11. Thick part cooling member disposed inside the partial mold 1 so as to constitute a part of the inner surface 6 of the mold and having a thermal conductivity equal to or greater than that of the partial mold 1 21, and when cooling after filling the cavity 11 with molten metal, By making the degree lower than the temperature of the partial mold 1, the thick portion 36 (see FIG. 3) of the hub 32 (see FIG. 3) with which the cooling exposed surface 24 comes into contact with the wheel 31 for motorcycle (see FIG. 3). It is possible to cool at about the same rate or faster than the other parts. Here, the cooling rate refers to the magnitude of the temperature that decreases per unit time, and the greater the temperature decrease per unit time, the faster the cooling rate. In addition, when cooling at substantially the same speed, the cooling rate of the thick part is so high that the thick part after casting does not become brittle, in addition to the case where the temperature changes (cools) at exactly the same speed. The case where the cooling rate is slower than other parts is also included.

  As described above, according to the casting mold 100 of the present embodiment, when the cavity 11 is cooled after being filled with the molten metal, the thick part cooling member 21 is cooled to a temperature lower than that of the partial mold 1 to increase the thickness. The thick portion 36 (see FIG. 3) of the hub 32 (see FIG. 3) with which the cooling exposed surface 24 of the member cooling member 21 contacts is substantially the same speed as the other parts of the two-wheeled vehicle wheel 31 (see FIG. 3). Therefore, it is possible to manufacture the two-wheeled vehicle wheel 31 (see FIG. 3) excellent in strength of the thick portion 36 (see FIG. 3) of the hub 32 (see FIG. 3).

  The casting mold 100 of the present embodiment is arranged so that two partial molds 1 of an upper mold 2 and a lower mold 3 are opposed to each other with a core 5 interposed therebetween, and each of the upper mold 2 and the lower mold 3. The inner surface of each of the cavities 11 forms a spoke-forming gap portion 11a corresponding to the spoke. The inner surface of each of the upper mold 2 and the lower mold 3 and the outer surface of the core 5 form a hub of the cavity 11. A hub forming gap 11b, which is a portion corresponding to the above, is formed. A ring-shaped horizontal mold 4 is disposed on the outer periphery (corresponding to the outer periphery of the two-wheeled vehicle wheel) of the spoke-forming gap 11a, and the inner surface of each of the upper mold 2, the lower mold 3 and the horizontal mold 4 defines the cavity 11 Among them, a rim forming gap portion 11c which is a portion corresponding to the rim constituting the outer periphery of the motorcycle wheel is formed.

  The hub forming gap portion 11b is configured such that the hub 32 (see FIG. 3) after casting has a hollow shape surrounded by a wall portion (wall portion of the hub) 35 (see FIG. 3). Since the disc brake plate is attached by bolting (see FIG. 3), as shown in FIG. 3, the hub 32 (hub wall portion 35) is perpendicular to the central axis (rotary axis) of the motorcycle wheel 31. It is formed to have a single surface (disc brake plate mounting surface) 38. After casting, a screw hole 37 is formed on this surface, and the disc brake plate is fixed by bolting. Usually, in order to form the screw hole 37 in the disc brake plate mounting surface 38 in this way, a part of the wall portion 35 of the hub is thickened to form the thickened portion 36. The surface constitutes a part of the disc brake plate mounting surface 38, and after casting, a screw hole 37 is formed in the one surface of the thick portion 36.

  In order to form the thick portion 36 (see FIG. 3) as described above, the hub forming gap 11b of the cavity 11 shown in FIG. 1 is formed so that the hub 32 (see FIG. 3) after casting is perpendicular to the central axis. It has a shape corresponding to the hub 32 (see FIG. 3) so as to have one surface. Further, the thick part forming gap 12 having a shape corresponding to the thick part 36 (see FIG. 3) constitutes a part of the hub forming gap 11b, and the thick part 36 after casting (see FIG. 3). The thick portion 36 of the hub 32 (see FIG. 3) is configured so that one surface forms a part of one surface perpendicular to the central axis of the hub 32 (see FIG. 3) after casting. (See FIG. 3). In the casting mold 100 of the present embodiment, as shown in FIG. 3, the thick part forming gap 12 has a thick part 36 after casting at a position equidistant from the central axis of the two-wheeled vehicle wheel 31. It is formed so as to be arranged at five places on the wall portion 35 of the hub so as to be equally spaced from each other.

  In the casting mold 100 of the present embodiment shown in FIG. 1, a thick part cooling member 21 is disposed near the center of the lower mold 3. As shown in FIGS. 2 (a), 2 (b) and 2 (c), the thick part cooling member 21 includes a tubular refrigerant flow tube 22 through which the refrigerant F can flow, and a refrigerant flow tube. And a thick portion cooling rod 23 that is cooled through the refrigerant flow tube 22 when the refrigerant F flows through the refrigerant flow tube 22. Here, FIG. 2A is a plan view of the thick part cooling member 21 as viewed from the thick part cooling rod 23 side, and FIG. 2B is a thick part cooling of the thick part cooling member 21. It is the front view seen from the direction perpendicular | vertical to the stick | rod 23, FIG.2 (c) is AA sectional drawing of the member 21 for thick part cooling shown in FIG.2 (b). FIG. 2C is an example showing a state in which the thick part cooling rod 23 is joined to the refrigerant flow pipe 22.

  As shown in FIG. 2A, the refrigerant flow pipe 22 is a metal pipe formed in a ring shape, and the refrigerant F flows through the internal space of the pipe. The shape of the cross section cut along a plane perpendicular to the axial direction of the refrigerant flow tube 22 may be circular, but may be a polygon such as a quadrangle or a pentagon, an ellipse, or any other irregular shape. Five thick portion cooling rods 23 are arranged at equal intervals along the circumference of the ring in the ring-shaped portion of the refrigerant flow pipe 22. When the refrigerant flow tube 22 is cooled by the refrigerant F, the thick portion cooling rod 23 is cooled by removing heat from the refrigerant flow tube 22. Moreover, as shown in FIG.2 (c), the thick part cooling rod 23 is inserted in the hole formed in the refrigerant | coolant flow pipe 22, and is being fixed by welding a junction part. Thus, when joining the thick part cooling rod 23 to the refrigerant | coolant flow pipe 22, it is preferable to set it as the state which inserts the thick part cooling stick | rod 23 to the inside of the pipe | tube of the refrigerant | coolant flow pipe 22. FIG. By inserting the thick portion cooling rod 23 into the refrigerant flow tube 22 in this way, the thick portion cooling rod 23 comes into direct contact with the refrigerant flowing inside the refrigerant flow tube 22, so that the thick portion cooling rod 23 can be efficiently cooled.

  In the present embodiment, the thick part cooling rod 23 has a solid rod shape, but a flow path through which the refrigerant F can flow is also formed inside the thick part cooling rod 23. Good. Further, the shape of the thick part cooling rod 23 may be a columnar shape as in the present embodiment, but is a columnar shape such as a rectangular column, an elliptical columnar shape, or a columnar shape having an irregular shape. Also good. The material of the thick part cooling member 21 is mainly composed of at least one selected from the group consisting of copper, copper alloy, tungsten alloy, aluminum, aluminum alloy, iron and iron alloy having good thermal conductivity. It is more preferable that copper or a copper alloy is the main component. Brass is preferred as the copper alloy. And it is preferable that the thermal conductivity of this thick part cooling member 21 is the same as the thermal conductivity of the partial mold 1 (see FIG. 1) or larger than the thermal conductivity of the partial mold 1. More preferably, it is larger than the thermal conductivity. This is because the cooling by the refrigerant F is performed efficiently.

  Further, the five thick portion cooling rods 23 have substantially the same length, but this can be appropriately determined depending on the shape of the partial mold and the like, and may not be the same length. In the present embodiment, five thick portion cooling rods 23 are disposed in the refrigerant flow pipe 22 in correspondence with the five thick portions of the cast spokes for the motorcycle. When the thick part is other than five places, it is preferable to arrange the number of thick part cooling rods 23 corresponding to the number. Further, it is not necessary to have one thick portion cooling rod 23 for cooling one thick portion, and a plurality of thick portions are formed for one portion of the thick portion forming gap 12 shown in FIG. A thick part cooling rod 23 may be arranged. That is, for example, when five thick portions are formed, two thick portion cooling rods 23 are arranged for each thick portion, and a total of ten thick portion cooling rods 23 are cooled. It may be arranged in the flow tube 22. A different number of thick part cooling rods 23 may be arranged for each thick part.

  As shown in FIG. 2 (a), the refrigerant flow tube 22 is formed in a ring shape (circular shape). However, the refrigerant flow tube 22 does not have to be in a ring shape. Any shape may be used, and when the thick part cooling member 21 is disposed in the partial mold 1, the thick part cooling rod 23 (particularly the cooling exposed surface 24) disposed in the refrigerant flow pipe 22 is desired. What is necessary is just to form so that it may be arrange | positioned in this position.

  As the refrigerant F flowing through the refrigerant flow pipe 22, water, air, mist in which air and mist water are mixed can be used. Further, the flow rate and temperature of the refrigerant can be appropriately determined depending on the size and material of the wheel for a motorcycle, the temperature to be controlled (the amount of heat to be removed), the type of the refrigerant, etc. The flow rate is preferably 5 to 15 L / min, and the temperature is preferably 30 ° C. or less.

  The diameter of the refrigerant flow tube 22 and the diameter of the ring shape of the refrigerant flow tube 22 formed in a ring shape can be determined as appropriate depending on the size of the two-wheeled vehicle wheel to be cast.

  The length of the thick part cooling rod 23 and the diameter of the rod can be appropriately determined according to the size of the two-wheeled vehicle wheel to be cast, but when casting a motorcycle wheel having a normal size, the thick part cooling rod 23 is cooled. The length of the rod 23 is preferably 70 mm or less. The diameter of the cross section when cut along a plane perpendicular to the length direction is preferably 10 to 20 mm.

  In the thick part cooling member 21 formed as described above, as shown in FIG. 1, the cooling exposed surface 24 that is the end face of the thick part cooling rod 23 is exposed to the thick part forming gap 12. In addition, the exposed surface 24 for cooling is disposed inside the lower die 3 so as to constitute a part of the inner surface of the lower die 3 constituting the partial mold 1. The refrigerant flow tube 22 is embedded so that the surface formed by the ring shape is along the outer surface of the lower mold 3. In this way, the cooling exposed surface 24 is disposed so as to be exposed in the thick portion forming gap portion 12, and the coolant is allowed to flow through the thick portion cooling member 21, thereby making the cooling exposed surface 24 a partial metal. Since the temperature of the inner surface of the mold 1 can be lowered, when manufacturing a wheel for a motorcycle, the molten metal (in the thick portion forming gap 12) of the thick portion of the hub of the motorcycle wheel is cooled. When solidifying, the temperature of the molten metal in the thick part (solid metal after cooling) with which the cooling exposed surface 24 contacts is equal to the temperature of the molten metal in the other part of the hub (solid metal after cooling). Or it can be at a lower temperature. That is, the thick part of the hub can be cooled at substantially the same speed or faster than the other parts of the wheel for a motorcycle. Thereby, the thick part of the wheel for a motorcycle is not made fragile, but is formed densely as much as or more than the other part, and becomes a thick part with excellent strength suitable for forming a screw hole.

The strength of the thick portion of the motorcycle wheel manufactured using the casting mold of the present embodiment differs depending on the size and material of the motorcycle wheel. Is about 26-30 (N / mm ² ). This is because the strength (tensile strength) of the thick portion of the aluminum motorcycle wheel manufactured by the conventional method is 23-26 (N / mm ² ). Compared to the degree, it is greatly improved. In addition, the strength (tensile strength) of the portion other than the thick portion of the wheel for a motorcycle is usually about 24 to 28 (N / mm ² ) in the case of aluminum, and the casting mold according to the present embodiment. It is equivalent to or slightly inferior to the thick part of the wheel for a motorcycle manufactured using Here, the tensile strength is a value measured by a method based on JIS Z2241. Also, in terms of elongation, assuming that the elongation rate of the thick portion of the aluminum motorcycle wheel manufactured by the conventional method is B, and the elongation rate of the thick portion of the aluminum motorcycle wheel in the present embodiment is A. The value of “A / B × 100-100” is about 15 to 25, and the elongation ratio of the thick portion of the aluminum motorcycle wheel in the present embodiment is an aluminum motorcycle manufactured by a conventional method. It is about 15 to 25% higher than the elongation of the thick part of the wheel. Here, the elongation is a value measured by a method based on JIS Z2241.

  Although the cooling rate of the part other than the thick part of the wheel for motorcycles varies depending on the size and material of the wheel for motorcycles, when it is made of aluminum, the “DAS II value” is usually about 40 to 60. In the thick part, the “DAS II value” is about 60 to 80, and a cast hole is easily generated. Here, the “DAS II value” is a value measured by the method described in “Method for Measuring Dendritic Arm Spacing of Aluminum and Cooling Rate (1988) (Edited by the Japan Institute of Light Metals)”. A larger “DAS II value” indicates a slower cooling rate. On the other hand, when the thick part is cooled when the aluminum motorcycle wheel is manufactured with the casting mold of the present embodiment, the “DAS II value” is about 30 to 40. Thereby, the thick part of the wheel for a motorcycle is not made fragile, but is formed densely as much as or more than the other part, and becomes a thick part with excellent strength suitable for forming a screw hole. Similarly, when the material of the wheel for a motorcycle is other than aluminum, the cooling rate condition may be set so that the thick portion does not become brittle.

  When manufacturing a two-wheeled vehicle wheel using the casting mold 100 of the present embodiment shown in FIG. 1, for example, at 700 ° C. in the cavity 11 of the casting mold 100 adjusted to 400 to 500 ° C. Fill with molten aluminum. Thereafter, the casting mold 100 (partial mold 1 and core 5) other than the thick part cooling member 21 is naturally cooled, and the thick part cooling member 21 is forcibly cooled with cold water at 30 ° C. . Accordingly, only the portion corresponding to the thick portion of the hub of the motorcycle wheel is forcibly cooled by the cooling exposed surface 24. And when it cools to predetermined temperature, the cold water which flowed to the thick part cooling member 21 is stopped, the whole casting die 100 is naturally cooled, and when it becomes 400 degreeC, it is for motorcycles cast Remove the wheel. After the motorcycle wheel is taken out of the casting mold 100, the core 5 is pulverized and removed by vibrating the motorcycle wheel with an air hammer or the like.

  As the partial mold and the core constituting the casting mold of the present embodiment, the conventional partial mold and the core for manufacturing a wheel for a motorcycle are used except for the portion where the thick part cooling member is disposed. can do. And the part which arrange | positions the member for thick part cooling should just be formed by giving the cutting process etc. to the conventional partial metal mold | die. Further, the thick part cooling member can be produced by deforming a predetermined pipe into a predetermined shape such as a ring and connecting a predetermined number of thick part cooling rods by welding or the like.

  Although the method for disposing the thick part cooling member in the partial mold is not particularly limited, for example, it is preferable to dispose the thick portion cooling member by a method as shown in FIG. FIG. 4 is a partial cross-sectional view schematically showing a state in which the refrigerant flow tube 22 of the thick part cooling member is fixed to the partial mold 1 by the fixing member 41. When the thick part cooling member is disposed in the partial mold 1, the thick part cooling member is disposed at a predetermined position of the partial mold 1 (see, for example, FIG. 1). As shown in FIG. 4, it is preferable that a fixing member 41 is put on the refrigerant flow tube 22 and is fixed by a screw 43. The fixing member 41 is formed by forming a metal plate in a band shape, and is formed so as to bend along the outer periphery of the refrigerant flow tube 22 by curving the central portion thereof. Then, screw holes 42 and 42 are provided at both ends of the fixing member 41, and are fixed to the partial mold 1 by screws 43.

  As a method of disposing the thick part cooling member in the partial mold, a method as shown in FIG. 5 may be used. FIG. 5 is a partial cross-sectional view schematically showing a state in which the refrigerant flow tube 22 of the thick part cooling member is fixed to the partial mold 1 by the fixing member 41. When the thick part cooling member is disposed in the partial mold 1, the thick part cooling member is disposed at a predetermined position of the partial mold 1 (see, for example, FIG. 1). As shown in FIG. 5, it is preferable that a fixing member 41 is wound around the refrigerant flow tube 22 and fixed by screws 43. The fixing member 41 is formed of a metal plate in a strip shape, and screw holes 42 and 42 are formed at both ends thereof. When the thick member cooling member is fixed to the partial mold 1 by the fixing member 41, the fixing member 41 is wound around the outer periphery of the refrigerant flow tube 22, and the both end portions thereof are overlapped so that the screw holes 42 and 42 overlap each other. The screw 43 is passed through the screw holes 42 and 42, and the fixing member 41 is fixed to the partial mold 1 by the screw 43. Accordingly, the thick part cooling member around which the fixing member 41 is wound is fixed to the partial mold 1.

  When the thick member cooling member is fixed by the fixing member, the fixing member may be arranged in any number of places, for example, about 1 to 8 places so that a good fixing state can be obtained in the refrigerant flow pipe. It is possible to fix the thick part cooling member.

  The material of the fixing member is not particularly limited as long as the thick part cooling member can be fixed to the partial mold. For example, iron, aluminum, copper, brass, or the like can be used.

  INDUSTRIAL APPLICABILITY The present invention can be used for casting a wheel for a vehicle, and in particular, can be used for casting a wheel for a motorcycle while preventing a thick portion of the hub from becoming brittle.

It is sectional drawing which shows one Embodiment of the metal mold | die for casting of this invention. The thick part cooling member arrange | positioned in one Embodiment of the casting die of this invention is shown, FIG. 2 (a) is a top view, FIG.2 (b) is a front view, FIG.2 (c) Is a cross-sectional view. It is a top view which shows the wheel for two-wheeled vehicles manufactured using one Embodiment of the metal mold | die for casting of this invention. It is the fragmentary sectional view which showed typically the refrigerant | coolant flow pipe | tube and fixing member of the thick part cooling member arrange | positioned in one embodiment of the casting die of this invention. It is the fragmentary sectional view which showed typically the refrigerant | coolant flow pipe | tube and fixing member of the thick part cooling member arrange | positioned in one embodiment of the casting die of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Partial mold, 2 ... Upper mold, 3 ... Lower mold, 4 ... Horizontal mold, 5 ... Core, 6 ... Inner surface of partial mold, 7 ... Outer surface of core, 11 ... Cavity, 11a ... Spoke formation 11b... Hub forming cavity, 11c. Rim forming cavity, 12. Thick part forming cavity, 21. Thick part cooling member, 22. Refrigerant flow pipe, 23. Cooling rod, 24 ... exposed surface for cooling, 31 ... wheel for motorcycle, 32 ... hub, 33 ... spoke, 34 ... rim, 35 ... wall portion of hub, 36 ... thick part, 37 ... screw hole, 38 ... disc brake Plate mounting surface, 41 ... fixing member, 42 ... screw hole, 43 ... screw, 100 ... mold for casting.

Claims (4)

Two or more partial molds, and a core disposed inside the matched partial molds and defining a cavity by an inner surface and an outer surface of the partial molds, A casting mold used to cast a vehicle wheel having a hollow hub and spokes extending radially from the hub by filling the cavity with molten metal and then cooling,
The cavity has a thickness corresponding to the thick part of the hub so that the hub after casting has a thick part for forming a screw hole in a part of the wall part. While having a gap for part formation,
The partial mold so that a part of the surface (exposed surface for cooling) is exposed to the thick part forming gap of the cavity and constitutes a part of the inner surface of the partial mold. Further comprising a member for cooling the thick portion, the thermal conductivity being the same as that of the partial mold or greater than that of the partial mold.
When cooling after filling the cavity with the molten metal, the thickness of the thick part cooling member is made lower than the temperature of the partial mold, thereby allowing the exposed surface of the hub to contact the meat. A casting mold capable of cooling the thick portion at substantially the same speed or faster than other portions of the vehicle wheel.   The cavity has a hub-forming gap having a shape corresponding to the hub such that the hub after casting has one surface perpendicular to the central axis thereof, and the thick portion The forming gap portion constitutes a part of the hub forming gap portion, and one surface for forming the screw hole of the thick portion after casting is formed on the central axis of the hub after casting. The casting mold according to claim 1, wherein the casting mold has a shape corresponding to the thick portion of the hub so as to constitute a part of the vertical one surface.   The thick part cooling member is cooled through the refrigerant flow pipe when the refrigerant flows through the tubular refrigerant flow pipe capable of flowing the refrigerant and the refrigerant flow pipe disposed in the refrigerant flow pipe. The casting mold according to claim 1, further comprising a thick-walled part cooling rod.   The material of the thick part cooling member is mainly composed of at least one selected from the group consisting of copper, copper alloy, tungsten alloy, aluminum, aluminum alloy, iron and iron alloy. A casting mold according to any one of the above.

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