JP2000271719A - Casting apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a casting apparatus usable over for long term while improving maintainability of a gas venting mechanism for venting unnecessary air and gas for formation of a casting generated in the case of pouring molten metal into a cavity while maching to the mass-production. SOLUTION: Relating to the casting apparatus 1 constituted of metallic molds 10, 20, 30 for casting, plural holes 13, 14, 23 formed in the metallic mold for venting the air or the gas in the cavity 2 at casting time and ejector devices 45, 50 for separating the casting 3 in the metallic mold with ejector pins 43, 44, 53 inserted so as to be slidable into the holes while linking with the opening of the metallic mold and form fine spaces on the outer periphery, a part of the ejector pin 44 among the ejector pins disposes an expanding/shrinking means 45 at the connecting part with the ejecting device 40.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting apparatus having a degassing mechanism for releasing air and gas unnecessary for forming a casting generated when a molten metal is injected into a cavity formed by a casting mold. .

[0002]

2. Description of the Related Art Conventionally, in casting, when a molten metal is poured into a cavity formed by a plurality of divided molds,
Gas generated by a chemical reaction from the mold (core) itself cannot be released due to the air or the heat of the molten metal existing before the pouring into the cavity. The air and gas are factors that cause defects such as shrinkage cavities in the casting, and a gas release mechanism is required in the casting apparatus.

[0003] Japanese Patent Application Laid-Open No.
The one shown in Japanese Patent No. 66963 is known. In this, a piece provided with a slit opened in a mold communicating with a gas vent groove is provided. However, this device has poor maintainability for a device that performs continuous mass production due to clogging of the slits of pieces with fine foreign matter and the like peeled off from the cast product, and causes an increase in manufacturing cost. .

[0004] In some casting apparatuses, an extruder that operates to release the casting from the die at the same time or at a fixed interval when the die is opened after the casting has solidified in the cavity is operated. . The extrusion device operates the extrusion pin inserted through the hole formed in the mold in association with the opening of the mold so as to protrude from the surface forming the cavity. Therefore, a casting apparatus in which a function of a degassing mechanism is added to an extruding apparatus is used, paying attention to a hole through which an extruding pin is inserted. This casting apparatus has a mechanism in which a minute space is annularly or intermittently formed between a hole through which the push pin is inserted and the push pin, and air or gas is released from the minute space to an external space.
In this casting apparatus, even if minute foreign matter separated from the casting enters the minute space, the foreign matter is removed from the minute space by the movement of the push pin in the hole.

[0005]

However, the above-mentioned push-out pins are appropriately set at locations where air or gas accumulates in the mold, depending on the shape of the casting and the pouring position of the mold. Therefore, in some cases, the diameter of the push pin cannot be sufficiently secured, and there is a place where a relatively small diameter push pin is installed. Since the extrusion pin extrudes the casting, the extrusion pin having a small diameter also extrudes the casting. Therefore, depending on the degree of solidification, even when pressed with the same pressure, the extruded pin having a small diameter has a higher surface pressure, so that a depression or the like is formed, which may cause a problem in the product shape. In addition, a large pressure is often required to release the cast product from the mold, and the pressing force causes buckling of the small-diameter extrusion pin, and the casting device cannot operate normally continuously. It will be.

[0006] Therefore, the present invention can be used for a long period of time while improving maintainability so as to be suitable for mass production of a gas release mechanism for releasing air and gas unnecessary for forming a casting generated when a molten metal is injected into a cavity. It is an object of the present invention to provide a possible casting apparatus.

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention according to claim 1 is formed in a mold for casting and a mold for removing air or gas from the cavity during casting. In a casting apparatus comprising: a plurality of holes; and an extrusion device configured to release a casting in the mold by a plurality of extrusion pins slidably inserted into the holes in conjunction with opening of the mold. At least one or more extrusion pins of the pins form a minute space on the outer periphery between the holes,
In addition, since the expansion / contraction means is arranged at the connection part with the extrusion device, when the extrusion device is operated, the expansion / contraction device expands / contracts, and the pressing force transmitted to the casting of some of the extrusion pins is compared with other extrusion pins. To be greatly reduced
There is no occurrence of dents or the like that may cause problems in the product shape. Further, the casting apparatus can be used for a long period of time with normal operation without buckling of some of the push pins.

According to the second aspect of the present invention, since the expansion and contraction means is a piston device, it is possible to freely expand and contract a part of the push pins, so that the load on the push pins can be controlled by the applied pressure. .

According to the third aspect of the present invention, since the elastic member is used as the expansion / contraction means, the load on the push pins can be reduced by the pressure applied to some of the push pins with a simple structure.

[0010]

Embodiments of the present invention will be described with reference to the drawings. 1 is a sectional view of a casting apparatus according to the present invention, FIG. 2 is an enlarged view of a main part A of FIG. 1, and FIG. 3 is an enlarged view of a main part of another embodiment of the casting apparatus according to the present invention.

First, the configuration of the casting apparatus according to the present invention will be described.

As shown in FIG. 1, a casting apparatus 1 includes an upper die 10, a lower die 20 combined with the upper die 10, and a desired casting 3 by being combined with the upper die 10 and the lower die 20. And a core mold 30 forming the cavity 2 having the same shape.

The upper die 10 is composed of an upper die main body 11 and an upper die base 12, and is provided with an upper extruding device 40 that enables the upper die 10 to be moved up and down separately from the up and down movement. The upper extruding device 40 is provided with the upper die base 12.
And is composed of an upper extruding plate 41, a lower extruding plate 42, an extruding pin 43, and an extruding pin 44 having a small diameter. The pushing pin 43 is fixed to the pushing device 40 by sandwiching the large-diameter portion 431 formed at the upper end between the pushing upper plate 41 and the pushing lower plate 42. At the lower end of the push-out pin 43, a lower end surface 432 is inserted through a hole 13 formed in the upper die body 11 so as to form a part of the cavity 2 at the time of pouring. The diameter of the hole 13 is slightly larger than the outer diameter of the push-out pin 43, and there is a minute space communicating with the outer space. The extrusion pin 43 is disposed at an appropriate position in consideration of the air release position, the balance of the pressing force at the time of release, the shape of the upper die body 11, and the like so that the casting 3 can be released from the upper die body 11. You.

FIG. 2 is an enlarged view of a connecting portion between the push-out pin 44 and the push-out upper plate 41 and the push-out lower plate 42. FIG. 2A shows a state before the push-out device 40 operates. 2 (b) shows a state when the pushing device 40 is operating. A large-diameter space 46 is formed between the upper extruded plate 41 and the lower extruded plate 42, and a small-diameter hole 47 is continuously formed below the large-diameter space 46. In the large-diameter space 46, a large-diameter portion 44 having a diameter larger than the small-diameter hole 47 formed at the upper end of the push pin 44.
The small-diameter portion 440 is slidably inserted into the small-diameter hole 47. The ceiling surface of the large-diameter space 46 and the large-diameter portion 44
1, a heat-resistant spring 45 is arranged between
The push pin 44 is constantly urged downward. FIG.
As shown in (a), the lower end surface of the large-diameter portion 441 of the pushing pin 44 contacts the bottom surface of the large-diameter space 46 by the urging force of the spring 45 before the operation of the pushing device 40. At this time, the lower end of the push-out pin 44 is inserted into the small-diameter hole 14 formed in the upper die body 11 so that the lower end surface 442 forms a part of the cavity 2 at the time of pouring. The diameter of the small-diameter hole 14 is slightly larger than the outer diameter of the small-diameter portion 440 of the push-out pin 44, so that a small space communicating with the external space exists. Here, the pushing pin 44 means a pin having a smaller diameter than the other pushing pins 43. In particular, when the casting 3 is extruded by being directly connected to the pushing device 40, (1) casting It refers to a product that causes a depression on the ground surface of the product 3 that causes a problem in the product shape, or (2) a product that causes buckling due to a pressing force. Also, the push pin 44
When pouring into the cavity 2 and the molten metal is filled,
It is arranged at a position where air accumulates and where a sufficient hole diameter cannot be obtained.

The lower die 20 comprises a lower die body 21 and a lower die base 22, and is provided with a lower extruding device 50 that enables the lower die 20 to be moved up and down independently of the up and down movement. The lower extruder 50 is provided with the lower die base 22.
And is composed of an extruding lower plate 51, an extruding upper plate 52, and an extruding pin 53. Push pin 53
Pushes out the large-diameter portion 531 formed at the lower end of the upper plate 52.
And the extruding device 5
0 fixed. The upper end surface 532 of the push pin 53 is inserted into a hole 23 formed in the lower
Are arranged so as to form a part of the cavity 2 at the time of pouring. The diameter of the hole 23 is substantially the same as the outer diameter of the push pin 53 so that the push pin 53 can slide. The extrusion pin 53 is arranged at an appropriate position in consideration of the balance of the pressing force at the time of release, the shape of the lower die body 21, and the like so that the casting 3 can be released from the lower die body 21.

Between the upper die body 11 and the lower die body 21,
A runner 15 is formed, and molten metal injected into a sprue cup formed at one end of the runner 15 (not shown) is poured into the cavity 2 through the runner 15.

The core mold 30 includes a core mold body 31 and a communication passage 32 having a vent 33 for venting air or gas in the cavity 2 installed at one end. In addition, core type 30
Is movably connected to a moving rail 34 fixed to the lower die main body 21 and moves movably into and out of a space formed by the upper die 10 and the lower die 20. That is, the cavity 2
The core mold body 31 is formed by inserting the core mold body 31 into a space formed by combining the upper mold body 11 and the lower mold body 21. In addition, the core mold 30 may use a collapsible core mold made of sand or the like.

Next, the operation of the casting apparatus will be described.

First, as shown in FIG. 1, the upper mold 10, the lower mold 20, and the core mold 30 are combined to form the cavity 2, and the material forming the casting 3 is molten metal. Poured into a cup. The molten metal flows into the cavity 2 from the sprue cup via the runner path 15 and gradually fills the space in the cavity 2. At this time, the air existing in the cavity 2 before the injection is moved out of the minute spaces formed by the push-out pin 43 and the hole 13 and the push-out pin 44 and the small-diameter hole 14 due to the pressure increase accompanying the inflow of the molten metal. Released. Air and gas generated from the inside of the casting 3 are discharged from the vent 33 to the outside through the communication passage 32. The injection of the molten metal is stopped at the same time when the cavity 2 is completely filled, and this state is maintained until it solidifies.

When the molten metal solidifies, the core mold 30 is retracted by the rails 34 and the core mold body 31 is removed from the inside of the casting 3.
Release the mold. Subsequently, at the same time when the upper mold 10 and the lower mold 20 are opened, the lower pushing device 50 operates to move the pushing pin 53 upward relative to the downward movement of the lower mold 20. The upper end surface 532 of the push-out pin 53 presses the casting 3 upward to release it from the lower die body 21 and raise it together with the upper die 10. Then, push pin 53
Is separated from the casting 3 so that the upper die body 11 has the casting 3 attached thereto.

Subsequently, a carry-out device (not shown) is provided below the upper die 10, and the upper push device 40 moves the push pin 43 downward relative to the upward movement of the upper die body 11. Activate The lower end surface 432 of the push-out pin 43 presses the casting 3 downward to press the upper die body 1.
It is released from 1 and dropped downward. The casting 3
It is received by the unloading device and is unloaded from the casting device 1.

The push pin 44 is in a state as shown in FIG. 2A from the time of injection of the molten metal to the time when the casting 3 is released from the lower die body 21. That is, the lower end surface of the large-diameter portion 441 of the push-out pin 44 comes into contact with the bottom surface of the large-diameter space 46 by the biasing force of the spring 45. The biasing force of the spring 45 is appropriately set so that the push-out pin 44 does not move up and down due to the pressure of the molten metal. When the casting 3 is released from the upper die body 11, the pushing pin 44 tends to move in the same manner as the pushing pin 43 moved downward by the pushing device 40. But,
When the lower end surface 442 pushes the casting 3, the pushing pin 44 elastically deforms the spring 45 disposed in the large-diameter space 46, and moves downwardly of the pushing device 40 as shown in FIG. Is moved upward relative to the movement of.

In this embodiment, a spring is used as the elastic member, but heat-resistant rubber or the like may be used.

Lastly, another embodiment of the casting apparatus according to the present invention will be described.

The construction and operation of the casting apparatus are the same as those of the above-described embodiment except for the parts described later, and therefore description thereof will be omitted. I have.

FIG. 3 is an enlarged view of a connecting portion between the small-diameter push-out pin 64 and the push-out upper plate 41 and the push-out lower plate 42. FIG. 3A shows a state before the push-out device 40 operates. FIG. 3B shows a state when the pushing device 40 is operating. A large-diameter space 46 is formed between the upper extruded plate 41 and the lower extruded plate 42, and a small-diameter hole 47 is continuously formed below the large-diameter space 46. In the large-diameter space 46, an extrusion pin 64 is provided.
Piston portion 6 having the same diameter as the large-diameter space 46 formed at the upper end of the piston 6
The small diameter portion 640 is slidably inserted through the small diameter hole 47. Above and below the large diameter space 46,
Communication passages 48 and 49 connected to a pump (not shown) are formed, and fluid flows in and out.

As shown in FIG. 3A, before the operation of the pushing device 40, the pushing pin 64 is
Fluid flows in from 8 and the lower end surface of the piston portion 641 comes into contact with the bottom surface of the large-diameter space 46. At this time, the lower end of the push-out pin 64 is inserted into the small-diameter hole 14 formed in the upper die body 11 so that the lower end surface 442 forms a part of the cavity 2 at the time of pouring. The pressure of the fluid flowing from the communication passage 48 is appropriately set so that the pushing pin 64 does not move up and down due to the pressure of the molten metal.
As shown in FIG. 3 (b), when the casting 3 is released from the upper die body 11, the pushing pin 64 tries to move in the same manner as the pushing pin 43 moved downward by the pushing device 40. . However, push pin 6
Before the lower end face presses the casting 3, the fluid pressure 4 is released from the fluid pressure flowing through the communication passage 48, and thus the fluid 4 is moved upward relative to the downward movement of the pushing device 40. When the casting 3 is conveyed by a conveying device (not shown), the push pins 64 move into the communication paths 48 in the large-diameter space 46.
The fluid is made to flow further, and the state returns to the state of FIG.
Further, the fluid pressure applied from the communication passage 48 when the extruding device 40 is operated is not completely released, and (1) a depression which does not cause a problem in the shape of the product on the ground surface of the casting 3 or (2) Control may be appropriately performed to such an extent that buckling is not caused by the pressing force.

Although the communication passage 49 is formed so that the piston portion 641 can forcibly operate in order to improve maintainability, the communication passage 48 may be constituted only. In addition, air, machine oil, or the like is used as the fluid.

Although the fluid pressure flowing from the communication passage 48 is released, a pressure release valve (not shown) may be arranged between the communication passage 48 and the pump. In this case, when the pressure applied to the push pin 64 increases, the pressure release valve opens to reduce the pressure applied to the push pin 64. With this simple configuration, the push pin 64 can push the casting 3 with a certain degree of pressure, and can release the load when a load that hinders the long-term operation of the push pin 64 is applied. .

[0030]

As described above, in the casting apparatus according to the present invention, the expansion and contraction means expands and contracts when the extruder operates.
Since the pressing force transmitted to the casting of some of the extrusion pins is significantly reduced as compared with the other extrusion pins, there is no occurrence of dents or the like which may cause problems in the product shape. Further, the casting apparatus can be used for a long period of time with normal operation without buckling of some of the push pins.

Further, since the expansion and contraction means is a piston device, it is possible to freely expand and contract a part of the push pins, so that the load on the push pins can be controlled by the applied pressure.

Further, since the expansion and contraction means is an elastic member, the load on the push pins can be reduced by the pressure applied to some of the push pins with a simple structure.

[Brief description of the drawings]

FIG. 1 is a sectional view of a casting apparatus according to the present invention.

FIG. 2 is an enlarged view of a main part A of FIG.

FIG. 3 is an enlarged view of a main part of another embodiment of the casting apparatus according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casting apparatus 2 Cavity 3 Casting product 10 Upper die 20 Lower die 40, 50 Extruder 43, 53 Extruder pin 44, 64 Extruder pin (small diameter) 45 Spring 641 Piston part

Claims (3)

[Claims] 1. A casting mold, a plurality of holes formed in the mold for removing air or gas from the cavity during casting, and sliding into the holes in conjunction with opening of the mold. An extruding device configured to release the casting in the mold by a plurality of movably inserted extruding pins, wherein at least one of the extruding pins is provided with the hole. A casting device, wherein a minute space is formed in an outer periphery between the extruding devices, and expansion / contraction means is arranged at a connection portion with the extrusion device. 2. The casting apparatus according to claim 1, wherein said expansion and contraction means is a piston device. 3. The casting apparatus according to claim 1, wherein said expansion and contraction means is an elastic member.