JP2014104485A - Casting mold device of wheel for two wheeler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting mold device of a wheel for a two wheeler hardly causing a casting defect by preventing a molten metal violent time from continuing long even when using a side gate system.SOLUTION: A casting mold device 3 of a wheel 1 for the two wheeler comprises an upper die 32 and a lower die 31 for forming a spoke part cavity Cand defining an inner peripheral surface of a rim part cavity Cand a horizontal die 33 for defining an outer peripheral surface of the rim part cavity C, and the horizontal die 33 is provided with a dam forming space 331 having a connection part connected from the outer peripheral surface side to the rim part cavity C, and the dam forming space 331 is formed so that the connection lowest part 331L is positioned under the connection lowest part Cof the spoke part cavity.

Description

  It has a rim cavity that extends in a cylindrical shape in the vertical direction to form a rim part for a motorcycle wheel, and a spoke cavity that forms a spoke part for a motorcycle wheel, and the spoke cavity is on the inner peripheral surface of the rim cavity. The present invention relates to a mold device for a two-wheeled vehicle wheel connected to a central portion in the vertical direction.

  2. Description of the Related Art Conventionally, a mold apparatus using a low pressure casting method has been adopted as a mold apparatus for manufacturing a four-wheel vehicle wheel among vehicle wheels. The low-pressure casting method pressurizes the molten metal in the holding furnace and pours it from the weir through the stalk into the cavity, has a better material yield than the gravity casting method, and is widely used for the production of aluminum alloy wheels for automobiles. ing. The low pressure casting method can be divided into a center gate type, a multi gate type, a side gate type, and the like depending on the position where the weir is provided.

  In a mold apparatus for a four-wheel vehicle wheel using a low-pressure casting method, a disk part cavity that forms a disk part is arranged with a design surface down, and a rim part cavity that forms a rim part is an outer peripheral part of the disk part cavity. It extends upward from.

  In the center gate type mold apparatus, a weir is provided in the central portion on the design surface side in the disk portion cavity. In the multi-gate mold device, a plurality of weirs are provided at the lower end portion of the rim cavity in addition to the weir provided at the center portion on the design surface side, or the weir provided at the center portion on the design surface side is omitted. A plurality of weirs are provided only at the lower end portion of the rim cavity. Center gate type and multi-gate type mold apparatuses have a good material yield and can reduce the mold cost. On the other hand, these mold apparatuses are provided with weirs on the lower end portion of the rim cavity and on the design surface side of the disk cavity, and it is difficult to dispose cooling means for cooling the design surface side of the molten metal filled in the disk cavity. As a result, it is difficult to improve the strength and toughness on the design surface side of the disk portion by cooling with the cooling means and increasing the solidification rate of the molten metal.

  Therefore, when emphasizing strength and toughness on the design surface side of the disk portion, a side gate type mold apparatus may be employed. In the side gate type mold apparatus, a dam forming space having a connecting portion connected to the rim portion cavity from the outer peripheral surface side is provided, and a cooling means for cooling the molten metal filled in the disk portion cavity from the design surface side is easily arranged. For this reason, the molten metal is cooled by the cooling means that cools from the design surface side to increase the solidification rate, and the strength and toughness on the design surface side in the disk portion can be improved.

  On the other hand, the two-wheeled vehicle wheel is different from the four-wheeled vehicle wheel among the vehicle wheels.

  An example of a wheel for a motorcycle will be described with reference to FIG. Fig.1 (a) is a figure which shows the plane of the wheel for two-wheeled vehicles. FIG. 1B is a cross-sectional view taken along the line A-A ′ of the motorcycle wheel shown in FIG.

  As shown in FIG. 1A and FIG. 1B, the motorcycle wheel 1 includes a disc portion 11 and a rim portion 12 provided on the outer periphery of the disc portion 11. The disc portion 11 shown in FIG. 1 has a hub portion 111 formed in a substantially disc shape, and a plurality of spoke portions 112 extending from the hub portion 111 toward the rim portion 12 and connected to the rim portion 12. The hub portion 111 is formed with a hub hole 111a penetrating in a central portion thereof in a direction perpendicular to the paper surface in FIG. 1A (vertical direction in FIG. 1B). Hereinafter, the direction through which the hub hole 111a passes is referred to as the width direction of the motorcycle wheel 1. Further, the hub portion 111 is formed with a brake attachment portion 111b for attaching a brake (not shown) on the lower end portion side in FIG. Hereinafter, in the width direction of the motorcycle wheel 1, the side on which the brake mounting portion 111b is formed is referred to as one side, and the opposite side is referred to as the other side.

  The rim portion 12 is formed to extend in a cylindrical shape in the width direction, and each of the plurality of spoke portions 112 is connected to a center portion in the width direction on the inner peripheral surface of the rim portion 12. In the rim portion 12, rim flanges 12a are formed at both ends in the width direction, and humps 12b are formed at portions slightly closer to the center in the width direction than the rim flange 12a.

  As a mold apparatus for manufacturing the two-wheeled vehicle wheel 1, for example, a mold apparatus manufactured by a low pressure casting method described in Patent Document 1 is known. The mold apparatus described in Patent Document 1 is provided with a cavity so that the width direction of the two-wheeled vehicle wheel 1 is in the vertical direction. This mold apparatus is a multi-gate type in which a plurality of weirs are provided at the lower end of the rim cavity. For this reason, it is difficult to arrange a cooling means for cooling the molten metal filled in the disk portion cavity from the lower side, which is one side of the two-wheel vehicle wheel, as in the above-described four-wheel vehicle wheel mold apparatus. Furthermore, it is difficult to provide a cooling means for cooling the molten metal filled in the lower end side portion in the rim cavity. Therefore, if the cooling means for cooling the molten metal filled in the disk portion cavity from the lower side or the cooling means for cooling the molten metal filled in the lower end side portion in the rim portion cavity is provided, the above-described four-wheeled vehicle is used. As with the wheel mold apparatus, a side gate type can be considered.

JP-A-4-327356

  However, as shown in FIG. 1B, the two-wheeled vehicle wheel 1 has a plurality of spoke portions 112 connected to a central portion in the width direction on the inner peripheral surface of the rim portion 12. When the side gate type mold apparatus is used, the molten metal supplied to the cavity from the connecting portion of the dam forming space is first filled in the lower end portion of the rim portion cavity, and then rises in the rim portion cavity. When the lower end portion of the rim cavity is filled with the molten metal, the molten metal starts to be supplied to the spoke cavity. Here, the molten metal newly supplied to the cavity collides with the molten metal rising in the rim cavity. At the connection part where the spoke cavity is connected to the rim cavity, the molten metal continues to be supplied to the spoke cavity, and the newly supplied molten metal and the molten metal that has risen inside the rim cavity will collide for a long time. It will be. That is, until the spoke cavity is filled with the molten metal, the connecting portion is not filled with the molten metal, and the molten metal supplied to the cavity and the molten metal rising in the rim cavity will collide for a long time. Become. For this reason, in the said connection part, the state in which a molten metal violates easily continues for a long time. The longer the rampage time, the easier gas is generated and the air is more likely to be entrained, which may cause casting defects such as water wrinkles and blow holes.

  SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a mold apparatus for a wheel for a motorcycle that can prevent a casting defect from occurring for a long time even if a side gate type is used, and can hardly cause casting defects. .

A mold apparatus for a two-wheeled vehicle wheel of the present invention that solves the above-described object includes a rim cavity that extends in a cylindrical shape in the vertical direction that forms a rim part of a two-wheeled vehicle, and a spoke cavity that forms a spoke part of the two-wheeled vehicle wheel In the mold apparatus for a two-wheeled vehicle wheel, wherein the spoke cavity is connected to the central portion in the vertical direction on the inner peripheral surface of the rim cavity,
An upper mold and a lower mold that form the spoke cavity and define an inner peripheral surface of the rim cavity;
A horizontal mold that defines the outer peripheral surface of the rim cavity,
The horizontal mold is provided with a dam forming space having a connection portion connected to the rim cavity from the outer peripheral surface side,
The dam forming space is characterized in that a lowermost portion of the connection portion is positioned below a lowermost portion of the spoke portion cavity connected to the rim portion cavity.

  According to the two-wheeled vehicle wheel casting mold apparatus of the present invention, the dam forming space is such that the lowermost portion of the connection portion is positioned below the lowermost portion of the spoke portion cavity that is connected to the rim portion cavity. . For this reason, the molten metal rising in the rim cavity and the molten metal newly supplied to the cavity from the weir formation space collide below the portion of the spoke cavity that is connected to the rim cavity, and the rim cavity It becomes difficult to hit the part that leads to. Even if the molten metal supplied to the cavity and the molten metal rising in the rim cavity collide with each other at the lower end of the rim cavity, the thickness of the lower edge of the rim cavity is thin and the molten metal immediately The molten metal will not be violated for a long time. For this reason, it is possible to prevent the molten metal from escaping for a long time and to prevent casting defects.

  In the mold device for a motorcycle wheel according to the present invention, the uppermost portion of the connecting portion is positioned below the uppermost portion of the spoke portion cavity at the portion connected to the rim portion cavity. It is preferable.

  With the above configuration, the molten metal does not collide with the portion of the spoke portion cavity connected to the rim portion cavity, and the molten metal can be prevented from being violated for a long time, thereby making it difficult to cause casting defects.

  Furthermore, in the mold apparatus for a motorcycle wheel according to the present invention, the lower mold may have a cooling means for cooling the molten metal filled in the rim cavity.

  Since the lower mold has the cooling means for cooling the molten metal filled in the rim cavity, the solidification rate of the molten metal filled in the lower end side portion of the rim cavity can be increased, and the strength and toughness can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses a side gate type | mold, the casting_mold | template apparatus of the wheel for two-wheeled vehicles which can prevent that a molten metal violates for a long time and makes it difficult to produce a casting defect can be provided.

(A) is a figure which shows the plane of the wheel for two-wheeled vehicles. (B) is A-A 'sectional drawing of the wheel for two-wheeled vehicles shown to (a). It is sectional drawing which shows the internal structure of the casting_mold | template apparatus which manufactures the wheel for motorcycles shown in FIG. (A) is an expanded sectional view of the internal structure of the mold apparatus of the first modified example, showing an enlarged portion where the dam forming space is connected to the rim cavity, and (b) is the mold of the second modified example. It is an expanded sectional view which expands and shows the part which the dam formation space connects to a rim part cavity of the internal structure in an apparatus.

  Embodiments of the present invention will be described below with reference to the drawings.

  The embodiment of the present invention will be described by taking as an example a mold apparatus for manufacturing the two-wheeled vehicle wheel 1 shown in FIG.

  FIG. 2 is a cross-sectional view showing the internal structure of the mold apparatus 3 for manufacturing the motorcycle wheel 1 shown in FIG.

  The mold apparatus 3 shown in FIG. 2 adopts a side gate type, and includes a lower mold 31, an upper mold 32, and a pair of horizontal molds 33. These molds 31 to 33 are all molds.

  FIG. 2 shows the mold apparatus 3 which is closed. In FIG. 2, the lower die 31, the upper die 32, and the pair of horizontal dies 33 are not shown in FIG. For the sake of clarity, the lower die 31 is hatched downward to the left, the upper die 32 is downwardly hatched, and the pair of horizontal dies 33 are cross-hatched.

  The lower mold 31 shown in FIG. 2 is fixedly disposed on the lower mold platen 34. On the other hand, the upper mold 32 is movable up and down. The upper mold 32 is fixed to an upper mold platen (not shown) and moves up and down as the upper mold platen moves up and down.

  The pair of horizontal dies 33 opens when the molds are separated from each other, and closes the molds by approaching each other until they come into contact with each other.

  The horizontal mold 33 shown in FIG. 2 performs mold closing and mold opening by sliding on a slide guide or the like (not shown) provided on the lower mold platen 34 in a direction perpendicular to the paper surface of FIG. Is called. FIG. 2 shows one horizontal mold 33 of the pair of horizontal molds 33. The one horizontal mold 33 is slid toward the front side of the sheet to close the mold and slide toward the back side of the sheet. That opens the mold.

  In the mold apparatus 3 shown in FIG. 2, the upper mold 32 descends on the fixedly arranged lower mold 31 and closes to each other until the pair of horizontal molds 33 come into contact with each other, so that the cavity C is formed. It is formed. In the motorcycle wheel 1 shown in FIG. 1, a horizontal mold 33 is formed on the outer peripheral surface of the rim portion 12, and the inner peripheral surface on one side of the disk portion 11 (lower side in FIG. 2) and one side of the rim portion 12 is lower. A mold 31 is formed. Further, the upper mold 32 forms an inner peripheral surface on the other side of the disk portion 11 (upper side in FIG. 2) and the other side of the rim portion 12.

  On the other hand, in the mold apparatus 3 that has been closed, the pair of horizontal molds 33 are separated from each other and the upper mold 32 is raised so that the mold is opened.

Cavity C has a rim cavity _{C R,} has a disk portion cavity _{C D,} the disc portion cavity _{C D} includes a spoke portion cavity _{C S,} and a hub portion cavity _{C H.} Rim cavity C _R is a space for forming the rim portion 12 of the motorcycle wheel 1 shown in FIG. 1, are disposed vertically and extends in a cylindrical shape. Further, the rim portion cavity _{C R} has a rim flange forming portion _{C RF} and hump forming portion _{C RH.} The rim flange forming portion _CRF is a space for forming a rim flange 12a included in the rim portion 12 of the motorcycle wheel 1 shown in FIG. Hump formation part _CRH is the space which forms hump 12b with which rim part 12 of wheel 1 for motorcycles shown in Drawing 1 is provided.

Disk portion cavity C _D is a space for forming the disk portion 11 of the motorcycle wheel 1 shown in FIG. Also, spokes cavity C _S of the disk portion the cavity C _D is a space for forming a spoke portion 112 of the motorcycle wheel 1 shown in FIG. Spokes cavity C _S is connected to the middle portion of the vertical direction of the inner peripheral surface of the rim portion cavity C _R. Hereinafter, the spokes cavity C _S, of the portion leading to the rim portion cavity C _R, referred to as the top connecting the top C _SH, referred to as the bottom connecting bottom C _SL. Connecting the top C _SH spokes cavity C _S is the rim cavity C _R, is positioned lower than the upper hump forming portion C _RH. The connecting bottom C _SL spokes cavity C _S is the rim cavity C _R, are located above the hump forming portion C _RH lower. Hub portion cavity C _H of the disk portion the cavity C _D is a space for forming a hub portion 111 of the motorcycle wheel 1 shown in FIG.

  In the mold apparatus 3 shown in FIG. 2, a gate 36 is formed on the upper surface of the lower platen 34. A stalk 37 is connected to the gate 36. The stalk 37 is inserted into a closed holding furnace (not shown), and a molten aluminum is held in the holding furnace, and a pressure of 0.01 MPa or more and 0.1 MPa or less is applied to the molten metal. Thus, the molten metal in the holding furnace reaches the gate 36 through the stalk 37.

The pair of horizontal 33, two weir having a connecting portion connected respectively from the mold-closing state positions 180 ° opposed to the circumferential direction of the cylindrical rim portion cavity C _R of the cavity C at its rim a cavity C _R A formation space 331 is provided. The molten metal that solidifies in the two weir formation spaces 331 becomes the weir. These two dam formation spaces 331 are formed in the split surfaces 33 a of the pair of horizontal molds 33. The right half of FIG. 2 shows a cross section along the split surface 33a of the pair of horizontal molds 33 in the mold apparatus 3, and the left half shows a cross section along a plane different from the split surface 33a. The weir formation space 331 is shown only on the right side of FIG. Note that the gate 36 is also provided at a position opposed to 180 °, but only the gate 36 on the right side is shown in FIG.

Hereinafter, among the weir forming space 331, a top of the connection portion connected to the rim portion cavity C _R, connected called top 331H, the bottom of the connecting portion connected to the rim portion cavity C _R, referred to as a connecting bottom 331L . Connecting top 331H of the dam forming space 331 is connected to the upper side of the hump forming portion _{C RH} moiety. The connection bottom 331L of the dam forming space 331 is connected to the hump forming portion _{C RH} portion of the lower. That is, the connection bottom 331L of the dam forming space 331 is positioned lower than the connecting bottom _{C SL} spokes cavity _{C S.}

  The pair of horizontal molds 33 also has a runner formation space 332 that connects the gate 36 and the weir formation space 331 in a closed state. This runner formation space 332 is also a space formed in the split surface 33a of the pair of horizontal molds 33. At the time of filling molten metal into the cavity C, the molten metal that has reached the gate 36 from a holding furnace (not shown) is filled into the cavity C from the weir forming space 331 through the runner forming space 332. The runner formation space 332 shown in FIG. 2 extends toward the dam formation space 331 by bending about 90 ° after the portion connected to the gate 36 rises. The thickness of the runner formation space 332 in the vicinity of the dam formation space 333 is thicker than the thickness of the runner formation space 332 in the vicinity of the gate 36.

In the central portion of the lower mold 31, a nest 310 is provided for forming a hub hole 111a provided in the hub portion 111 shown in FIG. The nest 310 protrudes toward the upper mold 32 and has a hollow inside, and an air-cooling pipe (not shown) is disposed in the inside. Furthermore, a water cooling pipe 311 for the hub part, a water cooling pipe 312 for the spoke part, and a water cooling pipe 313 for the rim part are arranged in the lower mold 31. Water cooling hub section pipe 311 is disposed below the hub cavity C _H, it is to cool the molten metal filled in the hub portion cavity C _H from below. Water-cooling pipe for spokes 312 is disposed below the spokes cavity C _S, is intended to cool the molten metal filled in the spokes cavity C _S from below. Rim-block water-cooling pipe 313 is disposed inside the rim cavity C _R, of the molten metal filled in the rim cavity C _R, in particular, the molten metal filled in the lower, the rim flange forming portion C _RF it is intended to cool the molten metal filled in the hump forming portion C _RH.

The upper mold 32 is also provided with a nesting 320. The insert 320 of the upper mold 32 is provided so as to close the opening 32b in the central portion of the upper mold 32. Nested 320 of the upper die 32 is to form a riser forming space R connected to the hub portion cavity C _H to form the hub portion 111 shown in FIG.

The upper mold 32 is provided with two types of cooling means, an air cooling pipe 324 and a mist cooling means 325. Cooling pipe 324, the upper die 32 is the tip is inserted into the spoke portion cavity C _S hole 324a formed on the upper surface of a portion forming a one for cooling the upper mold 32 by blowing air from the tip is there. The mist cooling means 325 is cooled by spraying water. Mist cooling means 325 shown in FIG. 2, the upper mold 32, the rim portion cavity C _R, on him the hump forming portion C _RH positioned above was sprayed with water, the molten metal filled in the rim cavity C _R Cool strongly. Cooling pipe 324 shown in FIG. 2 is for cooling the weir front part of the rim portion cavity C _R. On the other hand, the mist cooling unit 325, among the rim cavity C _R, in which the strong cooling 90 ° displaced portions in the circumferential direction of the rim cavity C _R weir front portion led respectively weir forming space 331. That is, the mist cooling means 325 is for strongly cooling the farthest portion from the dam front portion in the circumferential direction of the rim cavity C _R. There is a large difference in cooling capacity between the air cooling pipe 324 and the mist cooling means 325, and the mist cooling means 325 has a higher cooling capacity than the air cooling pipe 324. Thus, the mold apparatus 3 shown in FIG. 2, the rim cavity C _R, dam front portion from 90 ° shifted portion is strongly cooled, it can be most quickly solidify the portion. On the other hand, the front part of the weir remains relatively weakly cooled, and the front part of the weir can be finally solidified. Incidentally, the rim cavity C _R, and a cooling means for cooling the 90 ° shifted portion from the dam front portion, a means for cooling the weir front portion together may be a cooling pipe, or may be together as mist cooling means . When the two cooling means, both air pipes, or if you are both mist cooling means, by adjusting the mist amount and timing such that an air or mist blowing, the rim cavity C _R, weir before What is necessary is just to solidify the part which shifted 90 degrees from the part the earliest, and to solidify the part before a dam last. In other words, the rim portion cavity C _R, means for cooling the cooling means, the weir front portion to cool the 90 ° shifted portion from the dam front portion may be suitably selected and cooling pipe and mist cooling means.

  Then, the manufacturing method of the wheel 1 for motorcycles using the casting_mold | template apparatus 3 shown in FIG. 2 is demonstrated.

  First, foreign substances such as dust are removed from the molds 31 to 33 in a state where the mold is opened, and a strainer is set at the gate 36, and the mold apparatus 3 is closed.

Subsequently, a pouring process is performed in which the molten metal in the holding furnace (not shown in FIG. 2) is applied with a pressure of 0.01 MPa to 0.1 MPa to fill the cavity C of the mold apparatus 3 in which the mold is closed. Melt flows from the dam forming space 331 on the rim portion cavity C _R, comes gradually increased while being filled from the lower end portion of the rim cavity C _R. This increased come molten metal, until it reaches the connection bottom C _SL spokes cavity C _S, there are cases where the molten metal filled in the coming rising molten metal and the cavity C bumped melt rages. However, since the thickness of the lower end of the rim portion cavity C _R is the thin is immediately molten metal filling the molten metal fill level increases, the state in which the molten metal is violent bump into the molten metal at the same portions will not last long. Therefore, the lower end of the rim portion cavity C _R, casting defects due to unstable motion of the molten metal is less likely to occur.

When the molten metal reaches the connecting bottom C _SL spokes cavity C _S, the melt flows into the spokes cavity C _S. Melt after flowing into the spokes cavity C _S, the partial molten metal to the hub portion cavity C _H and spokes cavity C _S is charged, the rate at which the molten metal fill level rises slower. However, connecting the bottom 331L of the dam forming space 331 and are located below the coupling bottom C _SL spokes cavity C _S, among the molten metal supplied from the dam forming space 331, spoke cavity C _S amount is reduced to hitting the surface of the molten metal filled in the portion connected to the rim portion cavity C _R. For this reason, it is difficult for the molten metal to be violated, and it is possible to make it difficult for casting defects due to the violent molten metal to occur.

Continued for an additional supply of molten metal from weirs forming space 331, the hub portion cavity C _H, spokes cavity C _S, and the molten metal in the upper end portion of the rim portion cavity C _R is charged.

Thereafter, the mist cooling means 325 implemented mist cooling step of mist cooling, circumferential direction 90 ° shifted portion of the rim portion cavity C _R weir front portion is strongly cooled. Then, conduct cooling step of cooling by the cooling pipe 324, the rim cavity C _R, dam front portion is weak cooling. In this way, by accelerating the cooling start timing by the mist cooling means 325 from the cooling start timing by the air cooling pipe 324, the molten metal gradually solidifies from a position far from the pair of dam front portions toward the dam front portion. Sexual coagulation is achieved.

  In the lower mold 31, a water cooling process using water cooling pipes 311 to 313 is performed. In this water cooling step, water cooling is performed in the order of the water cooling pipe 311 for the hub part, the water cooling pipe 312 for the spoke part, and the water cooling pipe 313 for the rim part. As a result, the solidification rate of the molten metal filling the lower side of the hub part cavity, the lower side of the spoke part cavity, and the lower side of the rim part cavity is increased. As a result, the strength and toughness of one side of the hub portion 111 and one side of the spoke portion 112 of the motorcycle wheel 1 shown in FIG. 1 can be improved. Moreover, in particular, the strength and toughness of the rim flange 12a on one side and the hump 12b on one side can be improved in the rim portion 12 of the motorcycle wheel 1 shown in FIG.

  When a predetermined cooling time elapses, the mold is opened, and then the cast product is extracted from the mold apparatus 3, and then the feeder part and the weir of the cast product are cut. In addition, after the feeder part and dam of a cast product are cut | disconnected, appropriate heat processings, such as solution treatment, hardening, and aging, are given. Next, a cutting process is performed, and the casting material is formed into the shape of the wheel 1 for a motorcycle shown in FIG. After this cutting process, necessary painting is performed and the production of the wheel 1 for a motorcycle is completed.

Next, two modified examples of the mold apparatus 3 will be described with reference to FIG. These variations with respect to the mold device 3 came far described, the portion dam forming space 331 is connected to the rim cavity C _R are different.

  In the following description, differences from the mold apparatus 3 described so far will be mainly described, and redundant description will be omitted. In addition, the same constituent elements as those described so far may be denoted by the same reference numerals as those used so far, and the description thereof may be omitted.

  FIG. 3A is an enlarged cross-sectional view showing an enlarged portion of the internal structure of the mold apparatus 3 according to the first modification where the dam formation space is connected to the rim cavity. FIG. 3B is an enlarged cross-sectional view showing an enlarged portion of the internal structure of the mold apparatus 3 according to the second modification where the dam forming space is connected to the rim cavity. In FIGS. 3A and 3B, only the cavity C, the weir formation space 331, and the runner formation space 332 are shown without showing the casting mold in order to simplify the drawing.

As shown in FIG. 3 (a), the mold apparatus 3 of the first modification, the connection top 331H of the dam forming space 331, is positioned lower than the connecting top C _SH spokes cavity C _S . Therefore, the molten metal supplied to the cavity C is increased within the rim cavity C _R, even when the state flowing into the spokes cavity C _S was followed, among the molten metal supplied from the dam forming space 331, The molten metal hitting the molten metal surface is further reduced, and the molten metal can be further prevented from being ramped up. As a result, at a portion where the spoke portion cavity C _S is connected to the rim cavity C _R, it can be fewer casting defects due to unstable motion of the molten metal.

As shown in FIG. 3 (b), the mold apparatus 3 of the second modification connects the top 331H of the dam forming space 331 is positioned at substantially the same height as the connecting bottom C _SL spokes cavity C _S ing. Further, a mold apparatus 3 of the second modification connects the bottom 331L of the dam forming space 331, is connected to the rim flange forming portion C _RF portion of the rim cavity C _R. Therefore, even at the lower end portion of the rim cavity C _R, of the molten metal supplied from the dam forming space 331, it reduces the amount hitting the molten metal coming raised rim portion cavity C _R, the lower end of the rim portion cavity C _R The molten metal rampage at the part can be suppressed. Further, prevents the molten metal hits the portion of the rim portion cavity C _R to the spokes cavity C _S is connected, at a portion where the rim portion cavity C _R to the spokes cavity C _S is connected, the occurrence of casting defects due to unstable motion of the molten metal Can be reduced. Incidentally, the connection top 331H of the dam forming space 331 may be provided at a lower position than the connecting bottom _{C SL} spokes cavity _{C S.}

  As described above, according to the mold apparatus for a motorcycle wheel of the present embodiment, it is possible to prevent the molten metal from continuing for a long time and to prevent casting defects.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope described in the claims. For example, in the above embodiment, the position where the connecting bottom 331L of the dam forming space 331 is connected to the rim cavity C _R, has been under hump forming portion C _RH part of the side or rim flange forming portion C _RF portion, it may change the connection position within an amount below the coupling bottom C _SL spokes cavity C _S.

  In addition, even if it is a structural requirement contained only in each description of each modification demonstrated above, you may apply the structural requirement to another modification.

DESCRIPTION OF SYMBOLS 1 Motorcycle wheel 3 Mold apparatus 31 Lower mold 311 Hub water cooling pipe 312 Spoke water cooling pipe 313 Rim water cooling pipe 32 Upper mold 331 Weir formation space 331H Connection top 331L Connection bottom C Cavity CR _R rim cavity C _S spoke part cavity C _SH connection top part C _SL connection bottom part

Claims (3)

A rim cavity that extends in a cylindrical shape in the vertical direction and forms a rim portion of a wheel for a motorcycle, and a spoke cavity that forms a spoke portion of the wheel for a motorcycle, and the spoke cavity is an inner portion of the rim cavity. In the mold device for a motorcycle wheel connected to the central portion in the vertical direction on the circumferential surface,
An upper mold and a lower mold that form the spoke cavity and define an inner peripheral surface of the rim cavity;
A horizontal mold that defines the outer peripheral surface of the rim cavity,
The horizontal mold is provided with a dam forming space having a connection portion connected to the rim cavity from the outer peripheral surface side,
The mold for a two-wheeled vehicle wheel is characterized in that the dam forming space is such that a lowermost part of the connection part is located below a lowermost part of the spoke part cavity and a part connected to the rim part cavity. apparatus.   2. The dam formation space is such that the uppermost portion of the connection portion is located below the uppermost portion of the spoke portion cavity at the portion connected to the rim portion cavity. Molding device for motorcycle wheels.   The said lower mold | type has a cooling means to cool the molten metal with which the said rim | limb part cavity was filled, The casting_mold | template apparatus of the wheel for motorcycles of Claim 1 or 2 characterized by the above-mentioned.

Images