JP2014104486A - Die casting apparatus and method for manufacturing cast product using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a die casting apparatus with a simplified configuration for driving a control valve.SOLUTION: Provided is a die casting apparatus 1, in which a vacuum pump 20 is connected through an exhaust passage 17, a molten metal storage chamber 35 is communicated through a molten metal passage 18, and a powder storage container 40 is communicated through a powder passage 43 to a product part 16 where a product is formed on a cavity 11 of a mold 10. A driving means 50 drives an exhaust control valve 21 for opening and closing the exhaust passage 17 and a powder control valve 41 for opening and closing the powder passage 43 integrally. Thus, a number of the driving means for driving the exhaust control valve 21 and the powder control valve 41 can be reduced.

Description

  The present invention relates to a die casting apparatus and a method for producing a cast product using the same.

  Conventionally, there has been known a vacuum die casting apparatus in which a mold release agent is applied to a cavity of a mold, the cavity is evacuated, and then a molten metal such as an aluminum alloy (hereinafter referred to as “molten metal”) is injected and cast. (For example, refer to Patent Document 1).

JP-A-9-277007

In the die casting apparatus described in Patent Document 1, a powder suction passage, a sleeve, and a switching passage communicate with a product portion in which a product is formed in a cavity of a mold. The switching valve that moves in the powder suction passage and controls the opening and closing thereof, the powder control valve that moves in the sleeve, and the switching valve that switches the switching flow path are driven by separate driving devices. . For this reason, the die casting apparatus has a complicated structure for driving control valves such as a powder control valve and a switching valve. Therefore, there is a concern that the size of the die casting apparatus increases and the manufacturing cost increases.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a die casting apparatus with a simplified configuration for driving a control valve, and a method for manufacturing a cast product using the same.

According to claim 1 of the present invention, a die casting apparatus having an exhaust passage communicating with a product portion where a product is formed, a molten metal passage and a powder passage includes an exhaust control valve for opening or closing the exhaust passage and a powder passage. The powder control valve that opens or closes is integrally driven.
As a result, the number of drive means for driving the exhaust control valve and the powder control valve can be reduced. Therefore, by simplifying the structure of the driving means, the physique of the die casting apparatus can be reduced in size and the manufacturing cost can be reduced.

According to claim 9 of the present invention, the method for producing a cast product using a die casting apparatus moves the exhaust control valve and the powder control valve to the third position, and stores the powder release agent stored in the powder storage source. Is filled into the cavity by suction of a vacuum pump. Next, the exhaust control valve and the powder control valve are moved to the second position, and the air in the cavity and the molten metal storage chamber is sucked by the vacuum pump. Subsequently, the exhaust control valve and the powder control valve are moved to the first position, and the plunger injects the molten metal stored in the molten metal storage chamber into the cavity.
Thereby, in the manufacturing method of the cast product using the die casting apparatus, the exhaust control valve and the powder control valve can be integrally driven to manufacture the cast product.

It is principal part sectional drawing of the die-casting apparatus by 1st Embodiment of this invention. It is principal part sectional drawing of the die-casting apparatus by 1st Embodiment of this invention. It is principal part sectional drawing of the die-casting apparatus by 1st Embodiment of this invention. It is principal part sectional drawing of the die-casting apparatus by 1st Embodiment of this invention. It is explanatory drawing of operation | movement of the exhaust control valve and powder control valve by 1st Embodiment of this invention. It is principal part sectional drawing of the die-casting apparatus by 2nd Embodiment of this invention. It is principal part sectional drawing of the die-casting apparatus by 2nd Embodiment of this invention. It is principal part sectional drawing of the die-casting apparatus by 2nd Embodiment of this invention. It is explanatory drawing of operation | movement of the exhaust control valve and powder control valve by 2nd Embodiment of this invention. It is sectional drawing of the die-casting apparatus by 3rd Embodiment of this invention.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
1 to 5 show a die casting apparatus according to a first embodiment of the present invention. The die casting apparatus 1 performs casting by injecting a molten metal such as an aluminum alloy into a cavity 11 of a mold 10. The die casting apparatus includes a mold 10, a vacuum pump 20, an injection sleeve 30, a powder storage source 40, a driving means 50, and the like.
The mold 10 includes a fixed mother mold 12, a movable mother mold 13, and inserts 14 and 15. The insert 14 is fixed to the fixed mother mold 12 attached to the fixed plate 2 of the die casting apparatus main body, and the insert 15 is fixed to the movable mother mold 13 attached to the movable board 3 of the die casting apparatus main body.
The mother dies 12 and 13 and the inserts 14 and 15 have a cavity 11 including a product portion 16 in which a cast product is formed, an exhaust passage 17 communicating with the product portion 16, and a molten metal passage 18.

The vacuum pump 20 is connected to the exhaust passage 17 and sucks air in the cavity of the mold 10.
An exhaust control valve 21 provided in the exhaust passage 17 so as to be able to reciprocate opens or closes the exhaust passage 17. The exhaust control valve 21 has an exhaust valve main body 22 and an exhaust valve rod 23. The exhaust valve body 22 is in sliding contact with the inner wall of the exhaust passage 17 to close the exhaust passage 17, moves from the exhaust passage 17 into the cavity, and opens the exhaust passage 17. The exhaust valve rod 23 connects the exhaust valve main body 22 and the driving means 50.

The injection sleeve 30 includes a sleeve 31, a spool bush 32, and a guide bush 33 that have the same inner diameter and are arranged coaxially. The sleeve 31 and the spool bush 32 are fixed to the fixed mother die 12, and the guide bush 33 is fixed to the movable mother die 13.
A plunger 34 is provided inside the sleeve 31 and the spool bush 32 so as to be able to reciprocate. A powder control valve 41 is provided inside the guide bush 33 and the spool bush 32 so as to be able to reciprocate.
In the present embodiment, the inside of the guide bush 33 and the spool bush 32 in which the powder control valve 41 can reciprocate is referred to as a sliding hole 42.

Inside the injection sleeve 30, a molten metal storage chamber 35 in which the molten metal is stored is formed between the plunger 34 and the powder control valve 41. The molten metal storage chamber 35 is provided below the product portion 16 in the direction of gravity. The outer wall of the sleeve 31 is provided with a pouring hole 36 for supplying the molten metal to the molten metal storage chamber 35.
A delivery hole 37 communicating with the molten metal passage 18 is provided in the outer wall of the spool bush 32. Therefore, the molten metal storage chamber 35 and the sliding hole 42 communicate with the product portion 16 through the delivery hole 37 and the molten metal passage 18.

The powder storage source 40 communicates with a powder passage 43 formed in the powder control valve 41 and stores powder release agents such as wax, talc, and graphite made of powdered solid.
The powder passage 43 is formed inside the powder control valve 41, one end communicating with the powder storage source 40, and the other end opening on the outer wall of the powder control valve 41.
The powder control valve 41 includes a powder valve main body 44 and a powder valve rod 45. The powder valve main body 44 is in sliding contact with the inner wall of the sliding hole 42 to close the opening 431 of the powder passage 43, and moves through the sliding hole 42 so as to move the opening 431 of the powder passage 43 and the delivery hole of the spool bush 32. 37 is communicated. The powder valve rod 45 connects the powder valve main body 44 and the driving means 50.

The driving means 50 is composed of an air cylinder, a hydraulic cylinder, a motor, or the like, and is connected to the powder valve rod 45 of the powder control valve 41 and the exhaust valve rod 23 of the exhaust control valve 21. The driving unit 50 integrally drives the powder control valve 41 and the exhaust control valve 21 to switch to the first position, the second position, and the third position.
As shown in FIG. 5, when the driving means 50 places the exhaust control valve 21 and the powder control valve 41 in the first position, the end surface on the cavity side of the exhaust control valve 21 and the molten metal storage chamber 35 of the powder control valve 41. Both end surfaces are at the position of the broken line A. At this time, in the exhaust control valve 21, the exhaust valve main body 22 is in sliding contact with the inner wall of the exhaust passage 17 to close the exhaust passage 17. On the other hand, the powder control valve 41 is in sliding contact with the inner wall of the sliding hole 42 and closes the opening of the powder passage 43. In FIG. 5, a portion where the exhaust valve main body 22 and the inner wall of the exhaust passage 17 are in sliding contact and a portion where the powder control valve 41 and the inner wall of the sliding hole 42 are in sliding contact are indicated by broken-line ellipses, respectively.

  When the driving means 50 places the powder control valve 41 and the exhaust control valve 21 in the second position, the end face of the powder control valve 41 and the end face of the exhaust control valve 21 are both at the position of the broken line B. At this time, in the exhaust control valve 21, the exhaust valve main body 22 moves from the exhaust passage 17 into the cavity and opens the exhaust passage 17. On the other hand, the powder control valve 41 closes the opening of the powder passage 43 as in the first position.

  When the driving means 50 places the powder control valve 41 and the exhaust control valve 21 in the third position, the end face of the powder control valve 41 and the end face of the exhaust control valve 21 are both at the position of the broken line C. At this time, the exhaust control valve 21 opens the exhaust passage 17 as in the second position. On the other hand, the powder control valve 41 communicates the opening of the powder passage 43 and the delivery hole 37 of the spool bush 32 to open the powder passage 43.

Next, the manufacturing method of the cast product using the die casting apparatus 1 of this embodiment is demonstrated. This manufacturing method includes a mold clamping process, a release agent coating process, a pouring process, a vacuuming process, an injection process, a solidification process, and a product take-out process.
(Clamping process)
In the mold clamping process, as shown in FIG. 1, the movable platen 3 of the die casting apparatus main body is moved to bring the movable mother die 13 and its insert 15 into contact with the fixed mother die 12 and its insert 14. At this time, the driving means 50 brings the powder control valve 41 and the exhaust control valve 21 to the first position.

(Releasing agent application process)
Next, in the release agent application step, as shown in FIG. 2, the plunger 34 is moved to the left side to close the pouring hole 36.
The driving means 50 brings the powder control valve 41 and the exhaust control valve 21 to the third position. Therefore, the exhaust passage 17 communicates with the product portion 16 of the cavity 11, and the powder passage 43 communicates with the product portion 16 of the cavity 11 through the delivery hole 37 and the molten metal passage 18. Here, the vacuum pump 20 is driven to depressurize the cavity 11 to a predetermined degree of vacuum. Then, the powder release agent stored in the powder storage source 40 is sucked into the product portion 16 of the cavity 11 through the powder passage 43, the delivery hole 37, and the molten metal passage 18 due to the decompression of the cavity 11. It is applied to the inner wall of the product part 16.

(Pouring process)
In the pouring step, the plunger 34 is moved to the right from the state shown in FIG. Then, a predetermined amount of molten metal is injected from the molten metal hole 36 into the molten metal storage chamber 35.
(Evacuation process)
In the evacuation step, as shown in FIG. 3, the plunger 34 is moved to the left side to close the pouring hole 36.
The driving means 50 places the powder control valve 41 and the exhaust control valve 21 in the second position. Therefore, the exhaust passage 17 communicates with the product portion 16 of the cavity 11, and the powder passage 43 has its opening 431 closed by the powder control valve 41. Here, the vacuum pump 20 is driven, the air existing above the molten metal in the cavity 11 and the molten metal storage chamber 35 is sucked, and the cavity 11 and the molten metal storage chamber 35 are evacuated. Thereby, in the injection process after this, mixing of the air to a molten metal is prevented and the soundness of a cast product can be maintained. Note that the application thickness of the powder release agent can be made uniform by the vacuuming step.

(Injection process)
In the injection process, as shown in FIG. 4, the driving means 50 brings the powder control valve 41 and the exhaust control valve 21 to the first position. Therefore, the exhaust passage 17 is closed by the exhaust control valve 21 and the opening 431 of the powder passage 43 is closed by the powder control valve 41. Thereafter, the plunger 34 is moved to the left at a high speed, and the molten metal is injected from the molten metal storage chamber 35 through the molten metal passage 18 to the product portion 16 at a stretch.

(Coagulation process)
In the solidification step, the molten metal injected into the cavity 11 is cooled and solidified by keeping the mold clamping state for a certain time.
(Product removal process)
In the product take-out process, the movable platen 3 of the die casting apparatus main body is moved to open the movable mother die 13 and its insert 15 and the fixed mother die 12 and its insert 14. At this time, the product molded in the cavity 11 is in a state of being stuck to the inner wall of the insert 15 of the movable mother die 13, for example. Thereafter, an unillustrated push pin provided on the die casting apparatus main body is driven to remove the product from the inner wall of the insert 15 of the movable mother die 13. Thereafter, unnecessary parts of the taken out product are cut to complete a cast product.

The first embodiment has the following operational effects.
(1) In the first embodiment, the die casting apparatus 1 integrally drives the exhaust control valve 21 and the powder control valve 41 by one driving means 50. Thereby, since the structure of the drive means 50 becomes simple, the physique of the die-cast apparatus 1 can be reduced in size and the manufacturing cost can be reduced.

(2) In the first embodiment, the drive unit 50 switches the exhaust control valve 21 and the powder control valve 41 to the first position, the second position, and the third position. In the first position, both the exhaust passage 17 and the powder passage 43 are closed. In the second position, the exhaust passage 17 is opened and the powder passage 43 is closed. In the third position, both the exhaust passage 17 and the powder passage 43 are opened. In this way, by defining the first position, the second position, and the third position, the driving means 50 can drive the exhaust control valve 21 and the powder control valve 41 integrally.

(3) In the first embodiment, the molten metal storage chamber 35 is located below the product portion 16 in the gravity direction. Further, when the exhaust control valve 21 and the powder control valve 41 are in the first position and the second position, the molten metal storage chamber 35 is opened to the cavity 11 through the molten metal passage 18. Thereby, in the evacuation step, it becomes possible to suck air existing above the molten metal in the cavity 11 and the molten metal storage chamber 35. Therefore, in the injection process, air can be prevented from being mixed into the molten metal, and the soundness of the cast product can be maintained.

(Second Embodiment)
A die casting apparatus according to a second embodiment of the present invention is shown in FIGS. In the following embodiments, substantially the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.
In the second embodiment, the mold 10 is composed of a movable mold 101 and a fixed mold 102 for ease of explanation.

The injection sleeve 30 is connected to the cavity 11 of the mold 10. A plunger 34 is provided inside the injection sleeve 30. The molten metal storage chamber 35 is formed by the space inside the injection sleeve 30 and the space 110 formed coaxially with the injection sleeve 30 in the cavity 11 of the mold 10. The plunger 34 can reciprocate in the molten metal storage chamber 35.
The injection sleeve 30 may be inserted into the space 110 of the cavity 11 formed coaxially with the injection sleeve 30 as in the first embodiment.

The movable mold 101 has a sliding hole 46 that opens into the molten metal passage 18 that allows the molten metal storage chamber 35 and the product portion 16 to communicate with each other. That is, the opening on the side of the molten metal passage of the sliding hole 46 is located above the molten metal storage chamber 35 in the gravity direction.
The powder control valve 41 is provided to be able to reciprocate through the sliding hole 46. The powder control valve 41 is in sliding contact with the inner wall of the sliding hole 46 to close the opening 431 of the powder passage 43 and moves from the sliding hole 46 to the molten metal passage 18 to open the opening 431 of the powder passage 43. . When the powder control valve 41 opens the opening 431 of the powder passage 43, the opening 431 faces the product part side.

The driving means 50 integrally drives the powder control valve 41 and the exhaust control valve 21 to switch to the first position, the second position, and the third position as shown in FIG.
Regarding the first position, the second position, and the third position, the operations of the powder control valve 41 and the exhaust control valve 21 are the same as those in the first embodiment.

Next, the manufacturing method of the cast product using the die-casting apparatus of 2nd Embodiment is demonstrated.
(Clamping process)
In the mold clamping process, as shown in FIG. 6, the movable platen 3 of the die casting apparatus main body is moved to bring the movable mold 101 and the fixed mold 102 into contact with each other. At this time, the driving means 50 brings the powder control valve 41 and the exhaust control valve 21 to the first position.
(Releasing agent application process)
Next, in the release agent application step, as shown in FIG. 7, the plunger 34 is moved to the left side to close the pouring hole 36.
The driving means 50 brings the powder control valve 41 and the exhaust control valve 21 to the third position. Therefore, the exhaust passage 17 and the powder passage 43 communicate with the product portion 16 of the cavity 11. Here, when the vacuum pump 20 is driven and the cavity 11 is depressurized to a predetermined degree of vacuum, the powder release agent is discharged from the powder storage source 40 and applied to the inner wall of the product portion 16.

(Pouring process)
In the pouring step, the plunger 34 is moved to the right from the state shown in FIG. Then, a predetermined amount of molten metal is injected from the molten metal hole 36 into the molten metal storage chamber 35.
(Evacuation process)
In the evacuation step, as shown in FIG. 8, the plunger 34 is moved to the left side to close the pouring hole 36.
The driving means 50 places the powder control valve 41 and the exhaust control valve 21 in the second position. Therefore, the exhaust passage 17 communicates with the product portion 16 of the cavity 11 and the powder passage 43 is closed. Here, the vacuum pump 20 is driven, the air existing above the molten metal in the cavity 11 and the molten metal storage chamber 35 is sucked, and the cavity 11 and the molten metal storage chamber 35 are evacuated.

(Injection process)
In the injection process, the driving means 50 brings the powder control valve 41 and the exhaust control valve 21 to the first position. Therefore, the exhaust passage 17 and the powder passage 43 are closed. Thereafter, the plunger 34 is moved to the left at a high speed, and the molten metal is injected from the molten metal storage chamber 35 through the molten metal passage 18 to the product portion 16 at a stretch.
(Coagulation process, product removal process)
The coagulation process and the product removal process are the same as in the first embodiment.

  In the second embodiment, the sliding hole 46 opens to the molten metal passage 18 that communicates the molten metal storage chamber 35 and the product portion 16, and is provided above the molten metal storage chamber 35 in the gravity direction. Thereby, in the molten metal pouring process, when molten metal is poured into the molten metal storage chamber 35, the molten metal is prevented from entering the sliding hole 46. Further, the powder control valve 41 does not reciprocate in the molten metal storage chamber 35. For this reason, there is no so-called burr where the molten metal has solidified where the powder control valve 41 moves. Accordingly, since the operation of the powder control valve 41 is stabilized, the driving unit 50 can reliably move the powder control valve 41 from the first position to the third position.

(Third embodiment)
A die casting apparatus according to a third embodiment of the present invention is shown in FIG. FIG. 10 shows an extruding pin 61 slidably provided in an extruding passage 60 communicating with the product portion 16 of the mold 10. The extrusion pin 61 is used for extruding a product from the inner wall of the movable mold 101 in a product take-out step in a production process of a cast product using a die casting apparatus. The push pin 61 is operated by a driving device 51 that is inherently provided in the die casting apparatus. In FIG. 10, only the rod of the driving device 51 is shown.

The push pin 61, the powder control valve 41, and the exhaust control valve 21 are connected by a connecting member 52. The connecting member 52 may be a member that can attach and detach the push pin 61, the exhaust control valve 21, and the powder control valve 41, or may be a member that can be fixed. Thereby, the drive device 51 drives the push pin 61, the exhaust control valve 21 and the powder control valve 41 integrally.
When the exhaust control valve 21 and the powder control valve 41 are in the third position, the end surface on the product portion side of the push pin 61 is flush with the inner wall of the product portion 16, and the push pin 61 is stored in the push passage 60.
In the third embodiment, the driving device 51 corresponds to “driving means” recited in the claims.

  In 3rd Embodiment, the extrusion pin 61, the exhaust control valve 21, and the powder control valve 41 are integrally driven by the drive device 51 with which a die-casting apparatus is originally provided. Therefore, it is possible to simplify the configuration of the die casting apparatus without separately attaching driving means for driving the exhaust control valve 21 and the powder control valve 41. Therefore, the size of the die casting apparatus can be reduced, and the manufacturing cost can be reduced.

(Other embodiments)
The present invention is not limited to the above-described embodiment. In addition to combining the above-described plurality of embodiments, the present invention can be implemented in various forms without departing from the spirit of the invention.

DESCRIPTION OF SYMBOLS 1 ... Die casting apparatus 10 ... Mold 20 ... Vacuum pump 21 ... Exhaust control valve 34 ... Plunger 35 ... Molten metal storage chamber 40 ... Powder storage source 41 ... Powder Body control valve 50 ... drive means 51 ... drive device (drive means)

Claims (9)

A mold (10) having a cavity (11) containing a product part (16) in which the product is formed;
A vacuum pump (20) connected through an exhaust passage (17) communicating with the product part;
An exhaust control valve (21) for opening or closing the exhaust passage;
A molten metal storage chamber (35) communicating with the molten metal passage (18) communicating with the product portion and storing the molten metal;
A plunger (34) for injecting the molten metal stored in the molten metal storage chamber to the product part through the molten metal passage;
A powder storage source (40) for storing a powder release agent in communication with the powder passage (43) communicating with the product portion;
A powder control valve (41) for opening or closing the powder passage;
A die casting apparatus (1), comprising: driving means (50, 51) for integrally driving the exhaust control valve and the powder control valve. The drive means switches the exhaust control valve and the powder control valve to a first position, a second position, and a third position,
In the first position, the exhaust control valve closes the exhaust passage, the powder control valve closes the powder passage,
In the second position, the exhaust control valve opens the exhaust passage, the powder control valve closes the powder passage,
2. The die casting apparatus according to claim 1, wherein in the third position, the exhaust control valve opens the exhaust passage, and the powder control valve opens the powder passage. 3. The molten metal storage chamber is provided below the product portion in the direction of gravity,
2. The molten metal storage chamber is opened to a cavity through the molten metal passage when the driving means moves the exhaust control valve and the powder control valve to the first position and the second position, respectively. Or the die-casting apparatus of 2. The exhaust control valve is
An exhaust valve body (44) that slides into contact with the inner wall of the exhaust passage to close the exhaust passage, or moves from the exhaust passage into the cavity to open the exhaust passage;
The die casting apparatus according to any one of claims 1 to 3, further comprising an exhaust valve rod (45) for connecting the exhaust valve body and the driving means. The powder passage is formed in the powder control valve,
The powder control valve is provided in a sliding hole (46) communicating with the molten metal passage, and an opening (431) of the powder passage is closed by an inner wall of the sliding hole, and the molten metal is passed through the sliding hole. It moves to a channel | path and the said opening of the said powder channel | path is open | released, The die-cast apparatus as described in any one of Claims 1-4 characterized by the above-mentioned.   6. The die casting apparatus according to claim 5, wherein the sliding hole is provided between the molten metal storage chamber and the product portion.   The die casting apparatus according to claim 5 or 6, wherein the sliding hole is provided on the upper side in the gravity direction than the molten metal storage chamber. The extrusion passage (60) communicating with the product part is slidably provided, and includes an extrusion pin (61) for extruding the product from the product part,
The die casting apparatus according to any one of claims 1 to 8, wherein the driving means (51) integrally drives the push pin, the exhaust control valve, and the powder control valve. A method for producing a cast product using the die casting apparatus according to any one of claims 2 to 8,
The driving means moves the exhaust control valve and the powder control valve to the third position, and fills the cavity with the powder release agent stored in the powder storage source by suction of the vacuum pump. A release agent coating process;
A evacuation step in which the driving means moves the exhaust control valve and the powder control valve to the second position, and the vacuum pump sucks air in the cavity and the molten metal storage chamber;
The driving means moves the exhaust control valve and the powder control valve to the first position, and the plunger includes an injection step of injecting the molten metal stored in the molten metal storage chamber into the cavity. A method for producing a cast product using a die casting apparatus.

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