WO2013031967A1 - Casting mold device, casting method, and cast article - Google Patents

Abstract

A casting mold device has an enclosed space (21) between a sprue sleeve (7) and a sprue holder (6). The enclosed space (21) encloses the outer peripheral surface of the sprue sleeve (7). When the sprue sleeve (7) is positioned in a lower position (D), a molten metal with which a cavity (2) is filled enters the encircling space (21) and encloses the outer peripheral surface of the sprue sleeve (7). The enclosing continues while the sprue sleeve (7) rises to an upper position (U). An excellent cast product having no flaws or shape defects is thereby obtained.

Description

Mold apparatus for casting, casting method and casting

The present invention relates to a casting mold apparatus, a casting method, and a casting.

Conventionally, in gravity casting, a technique is known in which pouring is performed while adjusting the cross-sectional area of the pouring channel using a pouring sleeve in order to improve the rectification of the molten metal in the pouring channel and the effect of the pouring. (For example, refer to Patent Document 1).

In this technology, the molten metal is supplied to the pouring channel after the pouring sleeve is lowered to approach the boss molding projection to reduce the cross-sectional area of the channel from the lower part of the pouring channel to the cavity. As a result, the residence time of the molten metal in the pouring channel is extended to raise the impurities, and the clean molten metal flows into the cavity.

Also, immediately after the pouring into the cavity is completed, the pouring sleeve is raised to increase the cross-sectional area of the flow path from the lower part of the pouring channel to the cavity, so that the molten metal filled in the pouring channel functions as a hot water. Is trying to demonstrate.

JP 63-063550 A

However, according to the above-described prior art, since the sliding portion between the gate sleeve and the upper mold is provided in the vicinity of the cavity, there is a possibility that the molten metal adheres to and adheres to the sliding portion, and the sliding surface may be galling. . Moreover, the diameter of the cavity side end part of the gate sleeve increases due to thermal expansion due to the heat of the molten metal, and the surface pressure of the sliding surface increases.

When such sliding surface galling or high surface pressure occurs, it becomes difficult to move the gate sleeve. If the gate sleeve cannot move, defects or shape defects occur due to the turbulent flow of the molten metal or the lack of the hot metal effect, and a good cast product cannot be obtained.

An object of the present invention is to provide a casting mold apparatus, a casting method, and a casting capable of obtaining a good cast product free from defects and shape defects in view of the problems of the prior art.

A casting mold apparatus according to the present invention includes a mold that forms a cavity, a gate sleeve that functions as a gate and a feeder for the cavity, and a gate that is formed at a predetermined upper position and a lower position with respect to the cavity. An elevating part that moves up and down between the positions, and when the pouring sleeve is located at the lower position, the tip is located at a position corresponding to the inside of the cast product, and the mold is formed on the pouring sleeve. There is an opposing surface facing the outer peripheral surface, and there is an enclosed space between the outer peripheral surface and the opposing surface, the lower end being adjacent to the cavity and extending upward from the lower end. In the existence range of the direction, the outer peripheral surface is surrounded over the entire circumference, and the molten metal filled in the cavity enters the surrounding space when the gate sleeve is positioned at the lower position. The corresponding portion of the Kigaishu surface surrounds the entire periphery, the siege, characterized in that 該湯 port sleeve is also continued during the rise to the upper position.

In this configuration, filling of the molten metal into the cavity formed by the mold is performed in a state where the gate sleeve is lowered to the lower position by the elevating part. At this time, the front end portion of the gate sleeve is located at a position corresponding to the inside of the casting in the cavity. If the position of the tip portion is close to a predetermined inner wall surface in the cavity, the flow of the molten metal flowing into the cavity from the tip of the gate sleeve can be made into a laminar flow state.

In this state, the molten metal is filled into the cavity through the gate sleeve, and when the molten metal for the hot water is filled into the gate sleeve, the molten metal enters the surrounding space around the gate sleeve. As a result, the end portion of the gate sleeve is covered with the molten metal as a whole, and is thus sufficiently heated by the molten metal.

However, as the molten metal that has entered the enclosed space rises in the enclosed space, the temperature decreases and solidification progresses, and the rise stops when it rises to some extent. For this reason, even when there is a sliding portion between the gate sleeve and the mold above the enclosed space, a solidified product of the molten metal is caught in the sliding portion or galling occurs, which causes the gate gate to rise. There will be no hindrance.

In addition, since the outer periphery of the front end portion of the gate gate is an enclosed space, even if the diameter of the front end portion of the gate gate is somewhat enlarged by heating, the surface pressure of the sliding portion increases as in the conventional case, and the gate sleeve is increased. There is no fear that the rise will be hindered.

After this, when the gate sleeve rises, the tip portion of the gate sleeve is sufficiently heated, and the surrounding portion of the tip portion by the molten metal is continued, combined with the effect of the hot water in the gate gate. The molten metal around the tip portion flows without trouble and sequentially flows into the space generated by the rise of the gate sleeve. Moreover, the molten metal which flowed in and the molten metal of the vicinity fuse | melt without hindrance.

Thereafter, even after the gate sleeve reaches the upper position, the molten metal exists in the enclosed space, and the tip of the gate sleeve is kept warm, so that the molten metal that has flowed into the space generated by the rise of the gate sleeve and the space before the inflow Fusion with the molten metal that existed in the vicinity of is reliably performed. Moreover, a good hot water supply effect can be obtained by the hot water in the gate sleeve.

As described above, according to the present invention, the smooth movement of the gate gate is ensured, and the top end of the gate sleeve is heated and kept warm, so that the molten metal flows and fuses when the gate sleeve is raised and thereafter. Is surely done. Therefore, it is possible to obtain a good cast product free from defects and shape defects.

In the present invention, the mold includes a gate holder that holds the gate sleeve so as to be slidable in the ascending / descending direction, and an opposing surface facing the outer peripheral surface of the gate gate is configured by an inner peripheral surface of the gate holder. The enclosed space may be formed by a tapered surface included in one or both of an outer peripheral surface of the gate gate and an inner peripheral surface of the gate holder, and may be wider toward the cavity side. .

According to this, it is possible to accelerate the time when the molten metal rising in the enclosed space is solidified. Further, the amount of heat given to the gate sleeve by the molten metal in the enclosed space can be made larger on the cavity side. Therefore, a more optimized casting can be formed by appropriately setting the taper angle of the taper surface.

In the present invention, the upper part of the enclosed space on the outer peripheral surface of the gate gate and the inner peripheral surface of the gate holder is a sliding surface that slides relative to each other when the gate sleeve is raised and lowered. A vent for venting gas in the cavity may be provided on the moving surface. According to this, the gas in the cavity is discharged through the vent and is not taken into the molten metal. Therefore, it is possible to prevent the occurrence of defects such as oxidation of the material and hot water boundary due to the entrainment of air into the molten metal.

In the present invention, the mold may be a mold for molding a wheel for a wheel, for example. According to this, by configuring the casting mold device so that the axis of the wheel to be cast coincides with the axis of the gate sleeve, as described above, the wheel for a wheel having no defect or defective shape is cast. be able to.

At that time, when the gate sleeve is located at the lower position, the molten metal is supplied into the cavity in a laminar flow state if the tip of the gate sleeve is in a state close to the surface of the core forming the inner surface of the wheel hub. Can do. Therefore, a better wheel for a wheel can be cast.

The casting method of the present invention includes a lowering step of lowering a pouring sleeve provided on a mold constituting the cavity to a predetermined lower position, and after the lowering step, the molten metal is injected into the cavity via the pouring sleeve. And a rising step for raising the gate sleeve to a predetermined upper position after the filling step, and the lower position is such that the lower end of the gate sleeve is located inside the product to be cast. The position is such that the molten metal filled in the cavity flows into the cavity as a laminar flow from the gate sleeve. The front end portion of the gate sleeve is performed in a state surrounded by the molten metal supplied for filling the molten metal into the cavity.

According to this, the molten metal filled in the cavity can be caused to flow into the cavity in a laminar flow state from the gate sleeve. Further, as in the case of the above-described casting mold apparatus invention, the top end portion of the gate sleeve is sufficiently heated and kept warm by the molten metal, so that when the gate sleeve is raised, the space generated by the rise of the gate sleeve is hindered. Even after the molten metal flows and fuses and the spout sleeve reaches the upper position, the fusion of the molten metal is promoted, and a good hot-water supply effect can be obtained. Therefore, it is possible to obtain a good cast product free from defects and shape defects.

The casting of the present invention is cast using the following casting mold apparatus. The casting mold apparatus includes a mold that forms a cavity, a gate for filling the cavity with a molten metal, and a gate that functions as a feeder part, and the mold is an outer peripheral surface of the gate sleeve. Between the outer peripheral surface and the opposing surface, a lower end is adjacent to the cavity, and there is an enclosed space extending upward from the lower end. In the existence range, the outer peripheral surface is surrounded over the entire circumference. The casting has a surrounding space corresponding portion formed by the molten metal filled in the cavity entering the surrounding space and surrounding the corresponding portion of the outer peripheral surface over the entire circumference.

According to this, at the time of molding of the casting, as described above, the molten metal enters the surrounding space to form the cylindrical surrounding space corresponding portion. For this reason, even in the obtained casting, there is a flow of molten metal toward the enclosed space corresponding part. For this reason, in the vicinity of the surrounding space corresponding part, a clean molten metal free from gas entrainment or impurities is solidified smoothly. As a result, the structure in the vicinity of the surrounding space corresponding portion is refined and increased in strength.

The product of the present invention is obtained by cutting the above-described casting of the present invention. According to this, a good product free from defects and shape defects can be obtained.

The wheel for a wheel according to the present invention is characterized in that it is obtained by cutting a part including the part corresponding to the enclosed space and the part corresponding to the gate in the above casting to form a hub part. Thereby, the wheel for wheels without a defect and a shape defect can be obtained.

It is sectional drawing of the casting die apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows the vicinity part of the gate sleeve in the apparatus of FIG. FIG. 6 is another cross-sectional view showing the vicinity of the gate sleeve in the apparatus of FIG. 1. It is sectional drawing of the sleeve side sliding part and holder side sliding part of the apparatus of FIG. It is sectional drawing of the hub part of the casting obtained by the apparatus of FIG. It is sectional drawing which shows the principal part of the die apparatus for casting which concerns on the modification of the apparatus of FIG. It is sectional drawing which shows embodiment of the casting of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a casting mold apparatus according to an embodiment of the present invention. The casting mold apparatus 1 is for casting an aluminum wheel for a motorcycle.

As shown in FIG. 1, a casting mold apparatus 1 includes an upper mold 3, a lower mold 4, and a core 5 that form a cavity 2, a gate holder 6 fixed on the upper mold 3, and a gate holder 6. And a pouring sleeve 7 that moves up and down between a predetermined upper position U and a lower position D, a pouring cup 8 for pouring the pouring sleeve 7, and an elevating plate 9 that moves up and down integrally with the pouring sleeve 7. The core 5 is supported on the lower mold 4. The lower mold 4 is supported by the lower base B1.

The gate sleeve 7 functions as a gate and a feeder for filling the cavity 2 with molten metal. The gate sleeve 7 is connected to the lifting plate 9 via the joint plate 10 and the joint rod 11. The gate cup 8 moves up and down together with the gate sleeve 7. The elevating plate 9 is guided in the vertical direction by a support member 13 having a lower end fixed to the upper mold 3 and is moved up and down by a hydraulic cylinder 16.

The upper ends of the support member 13 and the hydraulic cylinder 16 are fixed to the upper base B2. The upper mold 3 is moved in the vertical direction together with the gate sleeve 7 and the like by the vertical movement of the upper base B2, and is thereby opened and closed with respect to the lower mold 4.

The gate holder 6 is fixed on the upper mold 3 via a holder fixing member 17. The holder fixing member 17 is provided with a stop member 18 for limiting the raising and lowering range of the gate sleeve 7. At the lower end of the joint rod 11, when the gate sleeve 7 is located at the upper position U, the upward first surface 19 that contacts the lower surface of the stop member 18, and when located at the lower position D, the stop member 18 A downward second surface 20 that contacts the top surface is provided.

The hydraulic cylinder 16, the stop member 18, etc. constitute an elevating part that raises and lowers the gate sleeve 7 between the upper position U and the lower position D with respect to the cavity 2.

That is, the hydraulic cylinder 16 moves the gate sleeve 7 up and down via the lift plate 9, the joint rod 11 and the joint plate 10. At that time, the hydraulic cylinder 16 moves the gate sleeve 7 to the lower position D by lowering the gate sleeve 7 until the second surface 20 contacts the stop member 18. Further, the gate sleeve 7 is moved to the upper position U by raising the gate sleeve 7 until the first surface 19 contacts the stop member 18.

2 and 3 are cross-sectional views showing the vicinity of the gate gate 7. FIG. 2 shows a state where the gate sleeve 7 is located at the lower position D, and FIG. 3 shows a state where the gate sleeve 7 is located at the upper position U. 2 and 3, the gate sleeve 7 includes a sleeve side tapered portion 7a, a sleeve side sliding portion 7b, and a coupling portion 7c, and is configured in this order from the distal end side (cavity 2 side).

The outer surface of the sleeve-side tapered portion 7a is a tapered surface (outer conical surface) whose diameter decreases toward the tip. The outer surface of the sleeve side sliding portion 7b is a cylindrical sliding surface. The upper end portion of the gate gate 7 is coupled to the lower end portion of the gate cup 8 through the coupling portion 7c.

The gate holder 6 includes a holder-side tapered portion 6a on the distal end side and a holder-side sliding portion 6b on the proximal end side adjacent thereto. The inner peripheral surface of the gate holder 6 corresponds to a facing surface that faces the outer peripheral surface of the gate gate 7. The inner surface of the holder-side tapered portion 6a is a tapered surface (inner conical surface) whose diameter increases toward the cavity 2 side. The holder side taper portion 6a has a length substantially equal to the sleeve side taper portion 7a.

The sleeve-side sliding portion 7b is vertically moved with respect to the holder-side sliding portion 6b while being supported by the holder-side sliding portion 6b in the horizontal direction when the gate sleeve 7 moves up and down between the upper position U and the lower position D. To slide. Throughout this raising / lowering period, a lower end is adjacent to the cavity 2 between the outer peripheral surface of the gate sleeve 7 and the inner peripheral surface of the gate holder 6 facing the gate sleeve 7, and an enclosed space 21 extending upward from the lower end is formed. Exists.

In the state of FIG. 2 in which the gate sleeve 7 is located at the lower position D, the enclosed space 21 includes a taper surface of the holder side taper portion 6a, a taper surface of the sleeve side taper portion 7a and a sleeve side sliding portion 7b opposed thereto. And the outer peripheral surface. In the state of FIG. 3 in which the gate sleeve 7 is located at the upper position U, the enclosed space 21 is configured as a space between the taper surface of the sleeve side taper portion 7a and the taper surface of the holder side taper portion 6a. Accordingly, the enclosed space 21 is widened toward the cavity 2 side.

FIG. 4 is a cross-sectional view of a portion where the sleeve side sliding portion 7b and the holder side sliding portion 6b are in contact with each other. As shown in FIG. 4, a groove-shaped vent 22 is provided on the inner surface of the holder-side sliding portion 6b. The vent 22 is formed in a range from the upper end of the holder side sliding portion 6b to a slightly lower end of the lower end, and communicates the enclosed space 21 with the outside of the upper mold 3. The gas in the cavity 2 is exhausted through the vent 22. In addition, you may provide the vent 22 in the sleeve side sliding part 7b.

In this configuration, when casting the aluminum wheel, the upper die 3, the lower die 4, and the core 5 are arranged and clamped to form the cavity 2 as shown in FIG. A hub portion 27a (see FIG. 5) is formed by a portion 2a around the core 5 in the cavity 2. Next, the gate sleeve 7 is lowered to the lower position D by the hydraulic cylinder 16.

Thereby, as shown in FIG. 2, the lower end of the gate sleeve 7 is close to the surface of the core 5 corresponding to the inner surface perpendicular to the axis of the hub portion 27a (see FIG. 5) of the aluminum wheel to be cast, A uniform gap 23 is formed between the surface. At this time, an enclosed space 21 exists between the holder-side taper portion 6a and the sleeve-side taper portion 7a and the sleeve-side sliding portion 7b facing the holder-side taper portion 6a.

Next, a molten aluminum alloy serving as a material for the cast aluminum wheel is supplied to the spout cup 8. The supplied molten metal flows from the lower end of the gate sleeve 7 through the gap 23 into the cavity 2 and is filled. At this time, since the molten metal passes through the uniform gap 23, it is rectified and flows into the cavity 2 as a laminar flow.

The molten metal is filled to a level sufficiently above the top of the core 5, for example, the level of the line 24, also in the gate sleeve 7 so as to obtain a good hot-water effect. At this time, the molten metal also enters the enclosed space 21. Thereby, since the front-end | tip part of the gate sleeve 7 will be in the state covered with the molten metal as a whole, it is fully heated by the molten metal.

However, as the molten metal that has entered the enclosed space 21 rises in the enclosed space 21, the temperature decreases and solidification progresses, and the rise stops when the temperature rises to some extent. For this reason, the molten metal coagulates between the sleeve-side sliding portion 7b and the holder-side sliding portion 6b above the enclosed space 21, or galling occurs, which hinders the rise of the gate sleeve 7. Absent.

Further, since the outer periphery on the front end side of the spout sleeve 7 is an enclosed space 21, even if the diameter on the front end side of the spout sleeve 7 is somewhat enlarged by heating, the surface pressure of the sliding portion increases as in the conventional case. The rise of the gate sleeve 7 is not hindered.

Next, the gate sleeve 7 is raised to the upper position U shown in FIG. During this time, the tip of the gate sleeve 7 is sufficiently heated, so that the molten metal around the gate sleeve 7 is ensured to have fluidity. Therefore, the molten metal around the gate sleeve 7 flows without hindrance and flows into the space that is sequentially generated by the rise of the gate sleeve 7. In addition, the molten metal flowing in and the molten metal in the vicinity of the molten metal are fused without hindrance.

Thereafter, even after the pouring sleeve 7 reaches the upper position U, the molten metal exists in the enclosed space 21 and the tip of the pouring sleeve 7 is kept warm, so that the molten metal that has flowed into the space generated by the rise of the pouring sleeve 7 Fusion with the molten metal existing around the space before inflow surely proceeds. In addition, a good hot water supply effect by the molten metal in the gate sleeve 7 is exhibited.

FIG. 5 is a cross-sectional view of a hub portion of a casting as an intermediate molded product obtained in this manner. As shown in FIG. 5, the casting 25 is formed by the product portion 27 having a shape that follows the shape of the cavity 2 and the molten metal in the gate sleeve 7 when the gate sleeve 7 is located at the upper position U. And the cylindrical surrounding space corresponding portion 29 formed by the molten metal that has entered the surrounding space 21 when the pouring sleeve 7 is located at the upper position U.

The casting 25 is subjected to cutting to remove a portion other than the portion surrounded by the thick line L1, and an aluminum wheel as a product is obtained. The part shown by FIG. 5 among the product parts 27 comprises the hub part 27a of an aluminum wheel.

In this aluminum wheel, since the cylindrical surrounding space corresponding portion 29 is formed in the casting 25, a flow of molten metal toward the surrounding space corresponding portion 29 is generated. In addition, since the pouring sleeve 7 is arranged inside the cavity 2 for pouring, the capacity of the molten metal to be poured is small at the beginning of pouring. For this reason, in the part which comprises the hub part 27a, the entrainment of gas and the clean molten metal without an impurity solidify smoothly, the structure | tissue is refined | miniaturized and the strength is increased.

A two-dot chain line L2 in FIG. 5 is a portion where the gate holder 6 is present at the time of casting, and a two-dot chain line L3 is a tip portion of the gate sleeve 7 when the gate sleeve 7 is located at the lower position D. The two-dot chain line L4 is a portion where the tip of the gate sleeve 7 was present when the gate sleeve 7 was positioned at the upper position U thereafter.

As shown in FIG. 5, the rise of the molten metal in the surrounding space 21 stops in the middle of the surrounding space 21. Moreover, the part where the front-end | tip part of the gate sleeve 7 existed in the downward position D is filled with the molten metal well, and becomes a part of aluminum wheel.

As described above, according to the present embodiment, the enclosed space 21 whose lower end is adjacent to the cavity 2 exists between the gate sleeve 7 and the gate holder 6, and the sleeve side sliding portion 7 b and the holder side sliding are present. Since the portion 6b is separated from the cavity 2, a solidified substance is caught between the sleeve side sliding portion 7b and the holder side sliding portion 6b, or galling occurs between the sleeve side sliding portion 7b and the holder side sliding portion 6b. Can be prevented.

Further, since the surrounding space 21 exists on the outer periphery of the gate sleeve 7, even if the diameter of the tip of the gate sleeve 7 is slightly enlarged by heating, the rise of the gate sleeve 7 is not hindered. Accordingly, it is possible to raise the gate sleeve 7 after filling the cavity 2 with no trouble.

Moreover, since the front-end | tip part of the gate sleeve 7 is fully heated by the molten metal which penetrate | invades in the surrounding space 21, the inflow and fusion of the molten metal to the space which arise after the gate sleeve 7 raises can be accelerated | stimulated without trouble. .

In addition, even after the gate sleeve 7 has been raised to the upper position U, the molten metal is present in the enclosed space 21 and the tip of the gate sleeve 7 is kept warm, so that it flows into the space generated during the rise of the gate sleeve 7. The fusion of the molten metal can be surely promoted, and a good hot water feeding effect by the hot water in the gate sleeve 7 can be obtained.

In addition, since the surrounding space 21 is configured by the sleeve side taper portion 7a and the holder side taper portion 6a so that the width becomes wider toward the cavity 2, the time when the molten metal rising in the surrounding space 21 solidifies is accelerated. In addition, the amount of heat given to the gate sleeve 7 by the molten metal in the enclosed space 21 can be increased on the cavity 2 side. Therefore, by appropriately setting the range and the taper angle of the sleeve side taper portion 7a and the holder side taper portion 6a, it is possible to perform the optimized molding without any defects or shape defects.

Further, since the vent 22 for venting the gas in the cavity 2 is provided in the holder-side sliding portion 6b, it is possible to prevent the occurrence of defects such as oxidation of the material and hot water boundary due to the entrainment of air into the molten metal. Can do.

FIG. 7 is a cross-sectional view of an embodiment of the casting of the present invention. In the casting mold apparatus used for casting the casting 30, a gate holder 31 and a gate sleeve 32 that are fixed in place until the molten metal is solidified are used instead of the gate holder 6 and the gate sleeve 7 described above. It is done.

That is, as shown by two-dot chain lines L6 and L7 in FIG. 7, the lower ends of the gate holder 31 and the gate sleeve 32 are positioned slightly higher than the upper end of the hub portion 27a of the aluminum wheel as a product until the molten metal is solidified. To position.

Also in this case, at the time of molding, an enclosed space is formed between the outer peripheral surface of the gate gate 32 and the inner peripheral surface of the gate gate 31 and the lower end is adjacent to the cavity and extends upward from the lower end. However, since the gate sleeve 32 and the gate holder 31 are not moved up and down until the molten metal is solidified, the enclosed space does not move.

Further, in order to mold the inner surface of the hub portion 27a, a core 33 having an umbrella-like portion at the upper end is used. The periphery of the umbrella-shaped portion and the gate sleeve 32 have a distance suitable for supplying molten metal. Other configurations are the same as those of the apparatus of FIG.

Also when the casting 30 is formed, the molten metal filled in the cavity enters the enclosed space between the gate gate 32 and the gate holder 31 and surrounds the outer peripheral surface of the gate sleeve 32 over the entire circumference to the height at which it has entered. Thereby, the cylindrical surrounding space corresponding | compatible part 34 is formed. For this reason, also in the casting 30, there is a flow of molten metal toward the enclosed space corresponding part 34.

In addition, since the space between the umbrella-shaped portion of the core 33 and the gate sleeve 32 has an appropriate space, the capacity of the molten metal to be poured is small at the beginning of pouring. Accordingly, in this case as well, a clean molten metal free from gas entrainment and impurities is smoothly solidified, so that the structure of the portion constituting the hub portion 27a is refined and the strength is increased.

Note that the present invention is not limited to the above-described embodiment. For example, in the above description, the case of casting an aluminum wheel for a motorcycle has been described. However, the present invention is not limited to this, and the present invention is not limited to this. For example, the casting of an aluminum wheel for a four-wheeled vehicle or a disk-shaped product is possible. It can also be applied to.

In the above description, the surrounding space 21 is configured as a space sandwiched between the tapered surfaces of both the sleeve-side tapered portion 7a and the holder-side tapered portion 6a. Instead, the tapered surface is provided only on one side. The space may be sandwiched between the cylindrical surface and the tapered surface.

Further, in the above description, the upper side of the enclosed space 21 is the sleeve side sliding portion 7b and the holder side sliding portion 6b, but if the horizontal position of the gate sleeve 7 is guided without any trouble, Such a sliding part may not exist.

Further, in the above description, the gate gate 7 is supported by the upper die 3 via the gate holder 6, but the gate sleeve 7 may be directly supported by the upper die 3 instead. In this case, an enclosed space and a sliding portion are formed between the upper mold 3 and the gate sleeve 7.

Further, instead of providing such a sliding portion and the gate holder 6, as shown in FIG. 6, a cavity is formed between the outer wall of the gate sleeve 7 and the upper mold 3 and the fixing member 17 facing the outer wall. A cylindrical space 26 communicating from 2 to the outside may be formed. In this case, the lower side of the space 26 functions as an enclosed space. However, the joint plate 10 and the joint rod 11 are appropriately guided on the basis of the upper mold 3 so that the gate sleeve 7 does not shake in the horizontal direction when the gate sleeve 7 is moved up and down.

The present invention is used for casting aluminum wheels and the like for motorcycles and automobiles. At that time, casting without defects and shape defects can be performed.

2 ... Cavity, 3 ... Upper mold, 4 ... Lower mold, 5 ... Core, 6 ... Sprue holder, 6a ... Holder side taper part, 6b ... Holder side sliding part, 7 ... Spout sleeve, 7a ... Sleeve side taper part 7b ... sleeve side sliding portion, 16 ... hydraulic cylinder, 18 ... stop member, 21 ... enclosure space, 22 ... vent, D ... lower position, U ... upper position.

Claims (8)

A mold for forming a cavity;
A gate for functioning as a gate and a feeder for filling the cavity with molten metal,
An elevating part that elevates and lowers the gate sleeve between a predetermined upper position and a lower position with respect to the cavity;
When the gate sleeve is located at the lower position, the tip is located at a position corresponding to the inside of the cast product,
The mold has a facing surface facing the outer peripheral surface of the gate sleeve;
Between the outer peripheral surface and the opposing surface, there is an enclosed space whose lower end is adjacent to the cavity and extends upward from the lower end, and the enclosed space has the outer circumferential surface in the range of the vertical direction. Siege all around,
The molten metal filled in the cavity when the gate sleeve is located at the lower position enters the enclosed space and surrounds the corresponding portion of the outer peripheral surface over the entire circumference, and the gate sleeve rises to the upper position. A mold apparatus for casting, characterized in that the siege is continued during the operation. The mold includes a gate holder that holds the gate sleeve so as to be slidable in the up-and-down direction,
The facing surface facing the outer peripheral surface of the gate gate is configured by the inner peripheral surface of the gate holder,
The enclosed space is formed by a tapered surface included in one or both of the outer peripheral surface of the gate gate and the inner peripheral surface of the gate holder, and has a width that increases toward the cavity. The casting mold apparatus according to claim 1. The upper portion of the enclosed space on the outer peripheral surface of the gate gate and the inner peripheral surface of the gate holder is a sliding surface that slides with each other when the gate sleeve is raised and lowered. The casting mold apparatus according to claim 2, wherein a vent for venting gas in the cavity is provided. The casting mold apparatus according to claim 1, wherein the mold is a mold for forming a wheel for a wheel. A lowering step of lowering the gate sleeve provided in the mold constituting the cavity to a predetermined lower position;
After the descending step, a filling step of filling the cavity with the molten metal through the gate sleeve,
A raising step of raising the gate sleeve to a predetermined upper position after the filling step;
The lower position is a position such that the lower end portion of the gate sleeve is disposed at a position corresponding to the inside of a product to be cast, and the molten metal filled in the cavity is laminar from the gate sleeve. It is a position to flow into the cavity,
The ascending step is performed in a state in which a lower end portion of the gate sleeve is surrounded by a molten metal supplied for filling the cavity with the molten metal. A mold that forms a cavity, and a gate for filling the cavity with a molten metal and a gate that functions as a feeder, and the mold has a facing surface that faces the outer peripheral surface of the gate sleeve. The space between the outer peripheral surface and the opposing surface has a lower end adjacent to the cavity and extending upward from the lower end, and the surrounding space completely covers the outer peripheral surface in the vertical range. A casting that is cast using a casting mold device that surrounds the circumference,
A casting having an enclosed space corresponding part formed by the molten metal filled in the cavity entering the enclosed space and surrounding the corresponding part of the outer peripheral surface over the entire circumference. A product obtained by cutting the casting of claim 6. A wheel for a wheel obtained by cutting a portion including an enclosure space corresponding portion and a gate corresponding portion of a casting according to claim 6 to form a hub portion.

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