CN216370099U

CN216370099U - Casting fitting

Info

Publication number: CN216370099U
Application number: CN202090000368.7U
Authority: CN
Inventors: 三轮一雅
Original assignee: Nippo Ltd
Current assignee: Nippo Ltd
Priority date: 2019-03-26
Filing date: 2020-03-23
Publication date: 2022-04-26
Anticipated expiration: 2030-03-23
Also published as: JP3222510U; WO2020196371A1

Abstract

A casting metal fitting (10) such as a casting mold or a hole forming pin has a heat insulating material (61) at a portion surrounded by a mold (50). The heat insulating material (61) is embedded in the surface except for the portion facing the cavity (80). The heat insulating material (61) is made of vespel polyimide resin having a higher heat resistance temperature than the temperature of the mold (50) during casting.

Description

Casting fitting

Technical Field

The present invention relates to a casting accessory to be mounted on a mold.

Background

In die casting, when a casting product having a complicated shape is manufactured, a casting mold may be used in a part of a mold. When a cast product having a cast hole is manufactured, a hole forming pin protruding toward a cavity is fixed in a mold. In order to prevent void defects (vacuum voids) in the cast product, the pin is used as a pressurizing pin that slides in the mold and can protrude into the cavity. Further, a quick-pull pin for thinning formation of an undercut (undercut) portion, a knock pin for demolding a molded article, or the like is used. For example, a hole forming pin is disclosed in Japanese patent laid-open No. 2004-268061. The pressurizing pin is disclosed in japanese patent application laid-open No. 7-214280. Further, the mold is used as a general term including a nest constituting a cavity.

In the case of aluminum die casting, the mold is heated to about 140 to 450 ℃ during casting. On the other hand, casting molds, hole forming pins, press pins, quick-release pins, knock pins, and the like (hereinafter, collectively referred to as casting metal fittings) are desired to be maintained at about 140 to 240 ℃ for ensuring durability or retaining a mold release agent, and a cooling structure for circulating cooling water may be provided inside.

SUMMERY OF THE UTILITY MODEL

Problem to be solved by utility model

However, the casting metal fitting is fixed in contact with the mold. Therefore, the cast metal fitting is heated by the heat of fusion from the material such as aluminum to be molded and the heat transfer from the mold receiving the heat of fusion. As a result, the durability of the cast component heated to a high temperature is reduced. The mold is cooled by the casting kit, particularly in the case where the casting kit has a cooling structure. Therefore, the preheating heat of the mold is taken away by the casting fitting, and additional preheating heat of the mold is required.

Thus, there is a need for improved casting fittings.

Means for solving the problems

A first aspect of the present disclosure is a casting component such as a casting mold or a hole forming pin, which is attached in a state of being surrounded by a mold to form a cavity together with the mold, and which has a heat insulating material that suppresses heat transfer between the mold and the casting component at a portion surrounded by the mold, the heat insulating material being embedded in a surface other than a portion facing the cavity, the heat insulating material being made of a resin having a heat resistant temperature higher than a temperature of the mold at the time of casting.

In the present disclosure, including the first aspect, with the nest in the mold, the mold is referred to as including the nest.

According to the first aspect, the portion surrounded by the mold of the cast metal fitting is surrounded by the heat insulating material. Therefore, heat transfer between the mold and the casting fitting is suppressed. As a result, the cast metal fitting is heated by the mold to a high temperature, and the durability of the cast metal fitting is prevented from being lowered. In the mold, the preheating heat energy can be inhibited from being taken away by the casting part, and the additional preheating heat energy is needed. Further, the heat insulating material is not provided in a portion facing the cavity. Therefore, the heat insulating material does not contact the melt forming the cast product in the cavity, and thermal degradation of the heat insulating material due to high heat of the melt can be suppressed. Further, the heat-resistant temperature of the heat-insulating material is set to be higher than the temperature of the mold during casting. Therefore, the heat insulating material can be inhibited from deteriorating in use.

A second aspect of the present disclosure is a casting component such as a press pin, including a cylindrical bush attached so as to be surrounded by a mold, and a rod-shaped pin protruding from both ends of the cylindrical bush while freely sliding along a cylindrical inner wall of the bush, the casting component forming a cavity together with the mold, including a heat insulating material that spreads along a sliding surface of the bush or a sliding surface of the bush at a portion where the bush and the pin slide, or an outer peripheral surface of the bush corresponding to the sliding surface, the heat insulating material being embedded in a surface of the bush or the pin other than a portion facing the cavity, the heat insulating material being made of a resin having a higher heat resistance temperature than a temperature of the mold at the time of casting.

According to the second aspect, the portion of the cast metal fitting surrounded by the mold has a heat insulating material along the sliding surface of the bushing and the pin or the outer peripheral surface of the bushing corresponding to the sliding surface. Therefore, heat transfer between the mold and the pin of the casting accessory is suppressed. As a result, the pins of the cast metal fitting are heated by heat from the mold to be heated to a high temperature, and the durability of the cast metal fitting is prevented from being lowered. In the mold, it is possible to suppress the heat energy of preheating from being taken away by the pins of the cast component and requiring additional preheating energy. The heat insulating material is not provided in a portion facing the cavity. Therefore, the heat insulating material does not come into contact with the melt forming the cast product in the cavity, and deterioration of the heat insulating material due to high heat of the melt can be suppressed. Further, the heat-resistant temperature of the heat-insulating material is set to be higher than the temperature of the mold during casting. Therefore, the heat insulating material can be inhibited from being deteriorated during casting.

A third aspect of the present disclosure is a casting component such as a knock pin, in which an elongated pin is attached to be slidable in an axial direction while being surrounded by a mold, a tip end portion of the pin forms a cavity together with the mold, and a heat insulating material is provided along an outer peripheral surface of the pin at a portion of the mold surrounding the pin and separated from the tip end portion facing the cavity, the heat insulating material being made of a resin having a higher heat resistance temperature than a temperature of the mold at the time of casting.

According to a third aspect, a portion of the pin has a thermally insulating material between the pin and the mold. Therefore, heat transfer between the mold and the pin of the casting accessory is suppressed. As a result, the pins of the cast metal fitting are heated by heat from the mold to be heated to a high temperature, and the durability of the cast metal fitting is prevented from being lowered. In the mold, it is possible to suppress the heat energy of preheating from being taken away by the pins of the cast component and requiring additional preheating energy. The heat-resistant temperature of the heat-insulating material is set to be higher than the temperature of the mold during casting. Therefore, the heat insulating material can be inhibited from being deteriorated during casting. Further, the outer peripheral surface of the portion separated from the tip end portion of the pin is slidably supported by the heat insulating material. Therefore, when the pin slides with respect to the mold, the tip end portion of the pin is supported by the mold, and a portion separated from the tip end portion is supported by the heat insulating material. Therefore, the pin is supported by the point 2 spaced apart in the sliding direction, and the sliding is smoothly performed.

A fourth aspect of the present disclosure is the first or second aspect, wherein a cooling structure is provided in a region surrounded by the mold.

According to the fourth aspect, the region surrounded by the mold in the casting fitting has a cooling structure. Therefore, the cast metal fitting is maintained at an appropriate temperature, and the mold can be prevented from being cooled to a low temperature by the heat insulating material.

A fifth aspect of the present disclosure is the heat insulating material according to any one of the first to third aspects, wherein the heat insulating material is made of a material having a linear expansion coefficient larger than that of the mold.

According to the fifth aspect, the thermal insulation material has a linear expansion coefficient larger than that of the mold. Therefore, the heat insulating material expands between the mold and the casting metal fitting or between the bush and the pin of the casting metal fitting at the time of casting, and the sealing property of the cavity can be improved. In other words, at low temperatures, the heat insulating material shrinks, and therefore, the insertion of the cast metal fitting into the mold or the insertion of the pin of the cast metal fitting into the bush can be facilitated.

A sixth aspect of the present disclosure provides any one of the first to third aspects, wherein the heat insulating material is made of a material having a lower compressive modulus of elasticity than the mold.

According to the sixth aspect, since the thermal insulator has a smaller compression modulus of elasticity than the mold, it is easily elastically deformed, and even if the casting metal fitting itself or the pin of the casting metal fitting vibrates by receiving the flow pressure of the melt forming the cast product in a state where the thermal insulator is in contact with both the mold and the casting metal fitting or between the bush and the pin of the casting metal fitting, it is possible to suppress damage in which the portion of the casting metal fitting itself or the pin of the casting metal fitting exposed to the cavity is broken by fatigue.

Drawings

Fig. 1 is a sectional view of a hole forming pin of a first embodiment of the present disclosure.

Fig. 2 is an enlarged sectional view of the front end portion of the hole forming pin.

Fig. 3 is an enlarged perspective view of the heat insulating material according to the first embodiment.

Fig. 4 is an enlarged perspective view of the heat insulating material according to the first embodiment.

Fig. 5 is an enlarged perspective view of a heat insulating material corresponding to fig. 3 according to a second embodiment of the present disclosure.

Fig. 6 is an enlarged perspective view of a heat insulating material corresponding to fig. 3 according to a third embodiment of the present disclosure.

Fig. 7 is a sectional view of a casting mold according to a fourth embodiment of the present disclosure.

Fig. 8 is a perspective view of a casting mold according to a fourth embodiment.

Fig. 9 is a perspective view of a casting mold corresponding to fig. 8 of a fifth embodiment of the present disclosure.

Fig. 10 is a perspective view of a casting mold corresponding to fig. 8 of a sixth embodiment of the present disclosure.

Fig. 11 is a sectional view of a pressing pin of a seventh embodiment of the present disclosure.

Fig. 12 is a sectional view of an ejector pin of an eighth embodiment of the present disclosure.

Detailed Description

< Structure of the first embodiment >

An embodiment of the present disclosure is explained with reference to the drawings. Fig. 1 shows a state in which a hole forming pin 10 (cast component) of a first embodiment of the cast component of the present disclosure is fixed to a mold 50. It is well known that the mold 50 also exists in the context of including nests. In this case, the mold 50 represents an example for casting of an aluminum product. The mold 50 may be used for casting other metal products, resin products, and the like.

The hole forming pin 10 is formed in a long shape, and is inserted into and fixed to the insertion hole 51 of the die 50. The holding hole 52 of the insertion hole 51 on the side closer to the cavity 80 has a diameter to be fitted into the holding portion 12 of the hole forming pin 10. Therefore, the holding hole 52 holds the holding portion 12 of the hole forming pin 10, and fixes the hole forming pin 10 in the mold 50. The portion of the insertion hole 51 other than the holding hole 52 has a larger diameter than the holding hole 52 and a slight gap from the pin body 11 (main body) of the hole forming pin 10. The diameter of the tip portion 13 of the hole forming pin 10 is smaller than the pin body 11 and the holding portion 12, and the tip portion 13 of the hole forming pin 10 is formed to protrude into the cavity 80. The proximal end portion 14 of the hole forming pin 10 has a larger diameter than the pin body 11 and an outer diameter larger than the inner diameter of the insertion hole 51. Therefore, when the hole forming pin 10 is inserted into the insertion hole 51, the base end portion 14 abuts on an end surface of the mold 50 forming the insertion hole 51, and insertion of the hole forming pin 10 is restricted at a predetermined position.

As shown in fig. 1 and 2, a cooling passage 15 (cooling structure) is formed from the base end portion 14 to the tip end portion 13 in the pin body 11 including the holding portion 12 and the tip end portion 13. A tubular cooling pipe 16 (cooling structure) is provided along the cooling passage 15 in the cooling passage 15. The cooling passage 15 and the cooling pipe 16 constitute a cooling structure of the present disclosure. Although not shown, cooling water flows through the cooling pipe 16 from the base end portion 14 side toward the tip end portion 13 side as indicated by arrows. The cooling water is discharged from the tip of the cooling pipe 16 to the cooling passage 15, and flows in the cooling passage 15 from the tip 13 side toward the base 14 side as indicated by arrows. The pin body 11 including the holding portion 12 and the distal end portion 13 is cooled by the flow of the cooling water.

As shown in fig. 1, a groove 12a is formed along the outer peripheral surface of the holding portion 12 of the hole forming pin 10 at 2. A heat insulating material 61 made of resin is fitted into each groove 12 a. That is, the heat insulating material 61 is embedded in the surface of the holding portion 12. Fig. 3 shows a pair of heat insulating materials 61 fitted into the respective grooves 12 a. The outer peripheral surface of the heat insulator 61 is disposed in contact with the inner peripheral surface of the holding hole 52. The heat insulating material 61 is disposed apart from the surface forming the cavity 80 so as not to be exposed to the surface forming the cavity 80. The heat insulating material 61a may be inserted into an end of the insertion hole 51 apart from the holding hole 52. As shown in fig. 4, the heat insulating material 61a has a circular ring shape. A candidate material for the

heat insulating materials

61 and 61a is vespel (registered trademark) SP-21 obtained by adding 15% by weight of graphite to a polyimide resin.

< action and Effect of the first embodiment >

vespel polyimide resin has heat resistance of about 500 degrees celsius, and when the mold 50 is used for casting aluminum, the mold temperature is about 400 degrees celsius, and therefore, has sufficient heat resistance. The vespel polyimide resin has a thermal conductivity (W/mK) of about 0.46 at around room temperature, which is smaller than that of 83 of iron. Therefore, the heat transfer between the mold 50 and the hole forming pin 10 is suppressed by the heat insulating function of the

heat insulating materials

61, 61 a. As a result, the temperature of the hole forming pin 10 can be prevented from being increased by heating the mold 50, and the durability thereof can be prevented from being lowered. In the mold 50, the thermal energy capable of suppressing the preheating from being taken away by the hole forming pin 10 and requiring additional preheating energy.

As described above, the heat insulating material 61 is provided apart from the portion facing the cavity 80. Therefore, the heat insulator 61 does not come into contact with the molten aluminum 70 (also referred to as a melt) in the cavity 80, and thermal degradation of the heat insulator 61 due to high heat of the molten aluminum 70 (approximately 600 degrees celsius) can be suppressed. The heat-resistant temperature of the heat-insulating

materials

61 and 61a is set higher than the temperature of the mold 50 during casting. Therefore, the

heat insulating materials

61 and 61a can be prevented from being deteriorated in use.

The vespel polyimide resin as the

heat insulating materials

61, 61a has a larger linear expansion coefficient than the mold 50. Namely, the linear expansion coefficient (10) of the tool steel constituting the die 50^-6/° c) was 12, and vespel polyimide resin was 41. Therefore, the

heat insulating materials

61 and 61a expand between the mold 50 and the hole forming pin 10 during casting, and the sealing property of the cavity 80 can be improved. That is, the

heat insulating materials

61 and 61a function as a sealing material. In other words, at low temperatures, since the

heat insulating materials

61, 61a shrink, it is possible to easily insert the hole forming pin 10 into the insertion hole 51 and the holding hole 52 of the mold 50.

In this way, the

heat insulating materials

61 and 61a function as a sealing material when the mold 50 is used. Therefore, the release agent (not shown) applied to the surface of the mold 50 forming the cavity 80 can be prevented from being vaporized by the high temperature of the melt and leaking out of the mold 50 through the insertion hole 51. The air existing outside the insertion hole 51 and the mold 50 and the leaked cooling water can be prevented from flowing into the cavity 80.

The vespel polyimide resin as the

heat insulators

61 and 61a has a smaller compressive elastic modulus than the mold 50 and a larger deformation amount per unit pressure. That is, the tool steel has a compressive modulus of elasticity (generally, about 300 ℃ C.) of "191000 MPa", and the vespel polyimide resin is "3200 to 3700 MPa". Therefore, even if the hole forming pin 10 vibrates by receiving the flow pressure of the molten aluminum 70 in a state where the

heat insulating materials

61 and 61a are in contact with the mold 50 and the hole forming pin 10, the

heat insulating materials

61 and 61a elastically deform to absorb the vibration. This can suppress damage that the portion of the hole forming pin 10 exposed to the cavity 80 is broken by fatigue.

< second embodiment >

Fig. 5 illustrates a second embodiment of the present disclosure. The second embodiment is characterized by changing the heat insulating material 61 to the heat insulating material 62 as compared with the first embodiment. The other structures are the same as those of the first embodiment, and the description of the same parts will be omitted.

As shown in fig. 5, the heat insulating material 62 has a shape in which a part of the pipe is cut off, and the pipe is opened within the range of elastic deformation so as to be fitted into the groove 12a of the holding portion 12 of the hole forming pin 10. Therefore, the groove 12a has a shape into which the heat insulating material 62 can be fitted. The heat insulating material 62 is different in shape from the heat insulating material 61 of the first embodiment, and has the same function.

< third embodiment >

Fig. 6 shows a third embodiment of the present disclosure. The third embodiment is characterized in that the heat insulating material 61 is changed to the heat insulating material 63, as compared with the first embodiment. The other structures are the same as those of the first embodiment, and the description of the same parts will be omitted.

As shown in fig. 6, the heat insulator 63 can be integrated by engaging the facing heat insulators 63 with each other. In the integrated state, the heat insulating material 63 has a tubular shape. The heat insulating materials 63 are engaged with each other by engaging the engaging convex portions 63a and the engaging concave portions 63b facing each other. In this case, the groove 12a is formed so as to surround the outer peripheral surface of the holding portion 12 once, and the heat insulating material 63 is fitted into the groove 12 a. As a result, the groove 12a is covered with the heat insulating material 63. The heat insulating material 63 is different from the heat insulating material 61 of the first embodiment only in shape, and has the same function.

< Structure of the fourth embodiment >

Fig. 7 and 8 show a fourth embodiment of the present disclosure. The fourth embodiment is characterized in that the cast metal fitting is changed from the hole forming pin 10 to the casting mold 20 (cast metal fitting) as compared with the first embodiment. The other structures are the same as those of the first embodiment, and the description of the same parts will be omitted.

As shown in fig. 7, the casting mold 20 has a 6-sided body shape of the mold body 21 as a whole and a protrusion 22 protrudingly formed on the upper surface of the mold body 21. The casting mold 20 is sandwiched between the molds 50 in the gap 53, and forms a cavity 80 together with the molds 50. Inside the casting mold 20, a cooling passage 23 (cooling structure) is formed in a range from the mold main body 21 to the protrusion 22. A cooling pipe 24 (cooling structure) is provided in the cooling passage 23. The cooling passage 23 and the cooling pipe 24 constitute a cooling structure of the present disclosure. This cooling structure functions in the same manner as the cooling structure of the first embodiment, and cools the casting mold 20.

Grooves 21a are formed in the respective side surfaces of the mold body 21 that contact the mold 50, and a square plate-shaped heat insulating material 64 is fitted into the grooves 21 a. The heat insulating material 64 is fitted into the groove 21a with lubricant oil as an adhesive. Fig. 8 shows a state before the heat insulating material 64 is fitted into the groove 21 a. The heat insulating material 64 is formed smaller than the side surface of the mold body 21 so as not to be exposed from the surface forming the cavity 80, and is disposed apart from the surface forming the cavity 80. The heat insulating material 64 is formed of vespel polyimide resin, as in the heat insulating material 61 of the first embodiment.

< action and Effect of the fourth embodiment >

According to the fourth embodiment, the function of the heat insulator 64 can suppress the temperature of the casting mold 20 from being increased by heating the mold 50, and the durability thereof from being lowered. In the mold 50, the preheating heat energy can be suppressed from being taken away by the casting mold 20 and additional preheating energy can be required.

The heat insulating material 64 is disposed away from the portion facing the cavity 80. Therefore, the heat insulating material 64 does not contact the molten aluminum 70 in the cavity 80, and therefore, thermal degradation of the heat insulating material 64 due to high heat of the molten aluminum 70 can be suppressed. The heat-resistant temperature of the heat insulating material 64 is set higher than the temperature of the mold 50 at the time of casting. Therefore, the heat insulating material 64 can be inhibited from being deteriorated in use.

During casting, the heat insulating material 64 expands between the mold 50 and the casting mold 20, and the sealing property of the cavity 80 can be improved.

In a state where the heat insulating material 64 is in contact with both the mold 50 and the casting mold 20, even if the casting mold 20, particularly the projection 22, receives the flow pressure of the molten aluminum 70 and vibrates, the heat insulating material 64 absorbs the vibration by elastic deformation. This can suppress damage to the projecting portion 22 of the casting mold 20 exposed to the cavity 80 due to fatigue fracture.

< fifth embodiment >

Fig. 9 shows a fifth embodiment of the present disclosure. The fifth embodiment is characterized in that the model body 21 is changed to the model body 25 and the heat insulator 64 is changed to the heat insulator 64a, as compared with the fourth embodiment (see fig. 7 and 8). The other structures are the same as those of the first embodiment, and the description of the same parts will be omitted.

As shown in fig. 9, the heat insulator 64a is attached so as to surround the periphery of the mold body 25 of the casting mold 20. Therefore, the groove 25a for inserting the heat insulating material 64a is formed around the circumference of the mold body 25. 4 (only 2 shown in fig. 9) heat insulators 64a are adhered to each other and fitted in the groove 25 a. The heat insulating material 64a is different from the heat insulating material 64 of the fourth embodiment only in shape, and has the same function.

< sixth embodiment >

Fig. 10 shows a sixth embodiment of the present disclosure. The sixth embodiment is characterized in that the model body 21 is changed to the model body 27 and the heat insulating material 64 is changed to the heat insulating material 64b, as compared with the fourth embodiment (see fig. 7 and 8). The other structures are the same as those of the first embodiment, and the description of the same parts will be omitted.

As shown in fig. 10, the model body 27 has a deformed cylindrical shape, and a groove 27a is formed around the circumference. A ring-shaped heat insulator 64b having a shape capable of fitting into the groove 27a is fitted around the groove 27 a. The heat insulating material 64b has a shape in which a part of the ring is cut off, and can be fitted into the groove 27a by opening the ring within the range of elastic deformation. The mold main body 27 and the heat insulating material 64b are different in shape from the mold main body 21 and the heat insulating material 64 of the fourth embodiment, and have the same function.

< Structure of the seventh embodiment >

Fig. 11 shows a seventh embodiment of the present disclosure. The seventh embodiment is characterized in that the cast metal fitting is changed from the hole forming pin 10 to the pressing pin 30 (cast metal fitting) as compared with the first embodiment. The other structures are the same as those of the first embodiment, and the description of the same parts will be omitted.

As shown in fig. 11, the pressing pin 30 has a substantially cylindrical bush 31 and a rod-shaped pin 32 that slides freely along the inner wall of the bush 31. The bush 31 has a shape in which the diameter of the bush is small on the tip side close to the cavity 80 and the diameter of the bush is large on the base side opposite to the tip side. The bush 31 is inserted into the insertion holes 54, 55 of the mold 50. The insertion holes 54, 55 are formed to correspond to the outer shape of the bush 31. The insertion hole 55 on the distal end side of the receiving bush 31 has a small inner diameter, and the insertion hole 54 on the proximal end side has a large inner diameter. The holding portion 31a on the tip end side of the bush 31 is fitted into and held by the holding hole 56 of the mold 50 having a diameter to be fitted into the holding portion 31 a. The proximal end 31b on the proximal end side is fitted into an insertion hole 54 of the mold 50 having a diameter to be fitted into the proximal end 31 b. A region between the holding portion 31a and the proximal end portion 31b of the bush 31 is inserted with a gap with respect to the insertion hole 55.

The length of the pin 32 is set so that the tip portion 35 and the flange portion 33 at the base end portion protrude from the bush 31. The pin 32 has a uniform thickness as a whole. The inner diameters of the

insertion holes

32a, 32b of the bush 31 which slidably receives the pin 32 are set to be larger at a portion corresponding to the base end portion 31b of the bush 31. The flange portion 33 is formed in a shape expanding like a flange with respect to the pin 32, and a compression spring 34 is interposed between the flange portion 33 and the base end portion 31 b. Therefore, when the flange portion 33 is pressed by an external force against the spring force of the compression spring 34, the tip portion 35 of the pin 32 protrudes into the cavity 80 as shown by the imaginary line. This operation crushes the pores in the melt 70. The operation of the pin 32 can be performed not only by a pressing operation but also by a driving mechanism (not shown) capable of performing a pulling operation. In this case, the output of the drive mechanism is coupled to the flange portion 33, so that the compression spring 34 is not required.

A heat insulator 65 is provided along a sliding surface with the insertion hole 32b on the outer peripheral side of the pin 32 corresponding to the holding portion 31a of the bush 31. The heat insulating material 65 is fitted into and embedded in the groove 31c formed in the outer peripheral surface of the pin 32. The heat insulating material 65 is disposed apart from the surface forming the cavity 80, and is not exposed to the surface forming the cavity 80 even when the distal end portion 35 of the pin 32 protrudes into the cavity 80. The heat insulator 65 is vespel polyimide resin as in the heat insulator 61 of the first embodiment, and has the same shape as the heat insulator 61.

As shown by the imaginary line in fig. 11, the heat insulator 65 may be formed on the outer peripheral surface of the holding portion 31 a. In this case, the heat insulator 65 is fitted into the groove 31c formed in the outer peripheral surface of the holding portion 31a and is brought into contact with the holding hole 56 of the mold 50.

On the inner diameter side of the base end side of the bush 31, a heat insulating material 66 is provided along a sliding surface with the pin 32. The heat insulating material 66 is fitted into a groove 31d formed in the inner wall surface of the base end portion 31 b. The heat insulating material 66 is vespel polyimide resin as in the heat insulating material 61a of the first embodiment, and has the same shape as the heat insulating material 61 a.

< action and Effect of the seventh embodiment >

According to the seventh embodiment, the pins 32 of the pressing pins 30 are prevented from being heated by the mold 50 to increase in temperature and from being reduced in durability by the function of the

heat insulating materials

65 and 66. In the mold 50, it is possible to suppress the heat energy for preheating from being taken away by the pin 32 and additional preheating energy is required. The pin 32 may be provided with the same cooling structure as the pin body 11 of the first embodiment.

The heat insulating material 65 is provided so as to be separated from the portion of the bush 31 or the pin 32 facing the cavity 80. Therefore, the heat insulating material 65 does not contact the molten aluminum 70 in the cavity 80, and thermal degradation of the heat insulating material 65 due to high heat of the molten aluminum 70 can be suppressed. The heat-resistant temperature of the heat-insulating material 65 is set to be higher than the temperature of the mold 50 at the time of casting. Therefore, the heat insulating material 65 can be inhibited from being deteriorated in use.

During casting, the

heat insulating materials

65 and 66 expand between the mold 50 and the pressurizing pin 30, and the sealing property of the cavity 80 can be improved.

The heat insulating material 65 is disposed between the mold 50 and the pin 32, and even if the pin 32 receives the flow pressure of the molten aluminum 70 and vibrates in a state of being in contact with both the mold 50 and the pin 32, the heat insulating material 65 can absorb the vibration by elastic deformation. Therefore, damage due to breakage of the pin 32 exposed in the cavity 80 due to fatigue can be suppressed.

The

heat insulating materials

65, 66 are in contact with the pin 32 from the tip side and the base side thereof, respectively. vespel polyimide resin has a low coefficient of friction when used as a bearing. As a result, the pin 32 is not in a cantilever-supported state, but is supported by the

heat insulating materials

65 and 66 as bearings in a double-supported manner. Therefore, the pin 32 can slide stably without being pried with respect to the bush 31.

< Structure of the eighth embodiment >

Fig. 12 shows an eighth embodiment of the present disclosure. The eighth embodiment is characterized in that the cast metal fitting is changed from the hole forming pin 10 to the knock pin 40 (cast metal fitting) as compared with the first embodiment. The other structures are the same as those of the first embodiment, and the description of the same parts will be omitted.

The pin body 41 of the knock pin 40 is formed long and inserted into the insertion hole 57 of the mold 50, and the tip portion 42 is held together with the mold 50 at a position where the cavity 80 is formed. The pin body 41 is pushed by an ejector mechanism (not shown) provided on a base end side away from the cavity 80, and slides in the axial direction, thereby functioning to push out a cast product formed in the cavity 80. That is, the tip portion 42 of the pin body 41 protrudes into the cavity 80, and the cast product is pushed out of the cavity 80.

The portion of the insertion hole 57 other than the slide hole 58 has a larger diameter than the slide hole 58, and a slight gap is provided between the portion and the pin body 41.

An annular heat insulator 67 is provided between the end of the insertion hole 57 of the mold 50 corresponding to the base end side of the pin body 41 and the outer peripheral surface of the pin body 41. The heat insulating material 67 is fitted into a groove 57a formed in an inner wall surface of an end portion of the insertion hole 57. The heat insulating material 67 is formed of vespel polyimide resin, as in the heat insulating material 61 of the first embodiment.

Action and Effect of the eighth embodiment

According to the eighth embodiment, the heat insulating material 67 slidably supports the pin body 41 at a position away from the distal end portion 42 of the pin body 41 toward the proximal end side. Vespel polyimide resin constituting the heat insulating material 67 has high heat insulating properties. Therefore, the pin body 41 can be prevented from being heated by the mold 50 to a high temperature, and the durability thereof can be prevented from being lowered. In the mold 50, it is possible to suppress the removal of the preheated heat energy by the pin body 41 and the need for additional preheated heat energy.

The pin main body 41 is not supported by the slide hole 58 in a cantilever bearing manner, but is supported in a double bearing manner in cooperation with the support of the heat insulating material 67. Further, vespel polyimide resin constituting the heat insulating material 67 has a low friction coefficient when used as a bearing. Therefore, the slide hole 58 of the die 50 is not pried and can be slid stably.

< other embodiments >

In the above description, specific embodiments have been described, but the present disclosure is not limited to these embodiments and can be implemented in various forms. For example, in the above embodiment, vespel polyimide resin is used as the heat insulating material, but any other resin can be used as long as it has the same performance. For example, a material containing carbon or other sliding fibers in the following resin can be used. As the resin, polyimide, polybenzimidazole, polyamide 46, polyether ether ketone, polyarylate, polyetherimide, or the like can be used. The temperature of the mold varies depending on the type of the cast product. Therefore, it is preferable to select a resin to be a heat insulating material according to the temperature.

The various embodiments described in detail above with reference to the drawings are representative examples of the present invention and do not limit the present invention. The detailed description is presented to enable one of ordinary skill in the art to make, use and/or practice the teachings and is not intended to limit the scope of the utility model. Further, each of the additional features and teachings described above may be applied and/or used alone or in combination with other features and teachings in order to provide improved cast fittings and/or methods of making and using the same.

Claims

1. A casting metal fitting which is attached in a state of being surrounded by a mold and forms a cavity together with the mold, characterized in that,

and a heat insulating material that suppresses heat transfer between the mold and the casting metal in a portion surrounded by the mold, the heat insulating material being made of a resin having a heat resistant temperature higher than a temperature of the mold during casting.

2. The casting fitting according to claim 1,

the heat insulating material is embedded in the surface of the main body of the casting metal fitting except for the portion facing the cavity.

3. The casting fitting according to claim 1,

a bushing having a cylindrical shape and a rod-like pin, the bushing being attached so as to be surrounded by the mold, the pin being slidable along a cylindrical inner wall of the bushing and protruding from both ends of the cylindrical shape,

the heat insulating material is expanded along a sliding surface of the pin or the sliding surface of the bush at a portion where the bush slides on the pin or an outer peripheral surface of the bush corresponding to the sliding surface,

the heat insulating material is embedded in a surface of the bushing or the pin except for a portion facing the cavity.

4. The casting fitting according to claim 1,

a pin having an elongated shape, the pin being attached so as to be slidable in an axial direction while being surrounded by the mold, a tip portion of the pin forming a cavity together with the mold,

the heat insulating material is provided along an outer peripheral surface of the pin at a portion of the mold surrounding the pin and spaced apart from the tip portion facing the cavity.

5. The casting fitting according to any one of claims 1 to 3,

a cooling structure is provided in the area surrounded by the mold.

6. The casting fitting according to any one of claims 1 to 4,

the heat insulating material is made of a material having a linear expansion coefficient larger than that of the mold.

7. The casting fitting according to any one of claims 1 to 4,

the heat insulating material is made of a material having a lower modulus of elasticity in compression than the mold.