JP3502585B2 - Powder release agent coating method and mold - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder mold releasing agent coating method and a metal mold for coating a powder mold releasing agent into a mold cavity formed by a fixed mold and a movable mold of an injection molding machine. Regarding the type.

[0002]

2. Description of the Related Art As a conventional injection molding machine, for example, FIG.
There is something like that shown in. Reference numeral 1 is a fixed-side mold having a mold surface corresponding to a product surface on one side. The fixed-side mold 1 is fixedly arranged on a fixed-side mold plate 8 of an injection molding machine. Reference numeral 2 denotes a movable side mold having a concave mold surface corresponding to the product surface on the other side. The movable side mold 2 is a movable side mold plate 9 via a slide base and a movable side mounting plate. It is fixed and arranged.

By contacting the facing surfaces of the fixed-side mold 1 and the movable-side mold 2 with each other, the fixed-side mold 1 and the movable-side mold 2 mold surfaces produce a product. A mold cavity 3 corresponding to the shape is formed. A heating nozzle 4 is provided at the tip of a heating cylinder that holds the molten metal.

A supply passage 31 communicating with the cold plug catcher 30 is formed in the movable side mold 2, and the supply passage 31 is formed.
A powder supply device 22 for supplying a powder release agent is communicated with the powder release agent to introduce the powder release agent into the mold cavity 3. On the other hand, the movable mold 2 has a mold cavity 3
At one end in the longitudinal direction of the cold plug catcher 3
An overflow groove 33 is formed on the side opposite to 0, and a discharge path 32 is formed in communication with the overflow groove 33. The discharge passage 32 is communicated with an exhaust pump 21 which is an exhaust means for exhausting the inside of the mold cavity 3 and a vacuum tank 20, and the powder release agent is supplied from the supply passage 31 immediately before the molten metal injection after the mold clamping. It is introduced, applied in the mold cavity 3, and exhausted and decompressed through the discharge passage 32 arranged at the other end.

The movable mold 2 is provided with opening / closing means which can be cut off and opened by being provided between the supply passage 31 and the cold plug catcher 30 and between the discharge passage 32 and the overflow groove 33. There is. The opening / closing means includes shutoff pins 34 and 35 and hydraulic cylinders 36 and 37. The shut-off pins 34, 35 are arranged in the movable-side mold 2 in the movable direction of the movable-side mold 2. The hydraulic cylinders 36, 37 move the shut-off pins 34, 35 relative to the mold cavity 3. The side mold 2 is slid in the movable direction. When the hydraulic cylinders 36 and 37 receive a signal notifying that the mold cavity 3 is sealed, the hydraulic cylinders 36 and 37 drive the shutoff pins 34 and 35 to open.

With this structure, the powder mold release agent is applied to the inside of the mold cavity 3. The powder release agent is used in the powder supply device 2
2 is introduced into the mold cavity 3 through the supply passage 31 communicated with the cold plug catcher 30 by a fixed amount by the compressed air 2 and the end opposite to the cold plug catcher 30 in the longitudinal direction of the mold cavity 3. The gas is exhausted through an exhaust passage 32 that communicates with an overflow 33 formed in the section. Evacuation of the exhaust passage 32 is performed by the exhaust pump 21 depressurizing the vacuum tank 20.

[0007]

As described above, in the conventional injection molding apparatus, the powder mold releasing agent is introduced into the mold cavity 3 through the supply passage 31 communicating with the cold plug catcher 30. Therefore, the supply path 31 and the exhaust path 32 for the powder release agent are formed in the movable mold 2, and the shutoff pins 34, 35 thereof and the hydraulic cylinders 36, 37 which are the drive sources thereof. Is arranged in the movable direction of the movable side mold 2, there is a problem that the thickness of the entire molds 1 and 2 becomes large. Further, since the supply passage 31 is communicated with the cold plug catcher 30, the position of the supply passage 31 is limited even when a hot nozzle is provided, and the supply passage 31 is arranged in the shape of the mold cavity 3. In some cases, it may be difficult to reliably apply the powder release agent to the inside of the mold cavity 3.

The present invention has been made to solve the above problems and provides a method and a mold for applying a powder release agent capable of supplying the powder release agent from an arbitrary position according to the shape of the product. With the goal.

Another object of the present invention is to provide a method and a mold for applying a powdery mold release agent, which can reduce the size of the mold.

[0010]

In order to solve the above problems, in the invention according to claim 1 of the present invention, a metal mold formed by a fixed mold (1) and a movable mold (2). In a mold release agent application method of applying a powder mold release agent into a mold cavity (3), the mold cavity (3) is provided with a fixed mold and communicates with one end of the mold cavity (3) immediately before injecting molten metal. And
The opening side is connected vertically to the moving direction of the movable mold (2).
As passing the supply passage is bent arranged to powder mold releasing agent from (11), by introducing the powder mold releasing agent, and a mold calibration
Mold (2) on the movable side that communicates with the other end of the duty (3)
The opening so that it communicates with the opening perpendicular to the moving direction of
It is characterized in that the air is exhausted from a bent exhaust passage (12).

According to the second aspect of the present invention, the powder mold release agent is composed of the fixed side mold (1) and the movable side mold (2), and the mold cavity (3) is formed by both molds. A mold mold cavity (3) provided on the stationary mold (1), and a powder mold release agent supply path (11) and discharge path (12) are provided at one end and the other end of the mold cavity (3). ) Is connected and the movable side
The opening is communicated in the direction perpendicular to the moving direction of the mold (2).
The supply path (11) is formed by being bent so that
A powder supplying means for communicating a powder releasing agent is provided to communicate with the discharge path (12) and the mold cavity (3).
Evacuation means for evacuating the inside is provided, and immediately before the molten metal injection after mold clamping, the powder mold release agent is introduced from the supply passage (11) to apply the powder release agent into the mold cavity (3) and the discharge passage. (1
2) It is characterized in that it is more exhausted.

According to a third aspect of the present invention, in the die according to the second aspect, the movable side die 2 is provided with the supply passages 11 and /
Or overflow grooves 13, which respectively communicate with the discharge path 12,
14 are respectively formed, the powder release agent is introduced through the overflow grooves 13 and 14 on the supply path 11 side, and the discharge path 12 is formed.
It is characterized in that it is exhausted through the side overflow grooves 13 and 14.

According to the invention of claim 4, claim 2 or 3
In the mold described above, the supply passage 11 and / or the discharge passage 12 are blocked from the supply passage 11 and / or the discharge passage 12.
It is characterized by comprising an opening / closing means that can be opened.

According to a fifth aspect of the present invention, in the mold according to the fourth aspect, the opening / closing means includes the shut-off pins 15 and 16 and the shut-off pin provided in the fixed-side mold of the movable-side mold. It is characterized by comprising hydraulic cylinders 17 and 18 which are driven in a direction perpendicular to the moving direction .

According to a sixth aspect of the present invention, in the mold according to any of the second to fifth aspects, a suction valve 19 that can be opened and closed is provided on the exhaust port 12 side. The invention according to claim 7 is characterized in that, in the mold according to any one of claims 2 to 6, a hot runner is arranged in the fixed-side mold 1.

According to an eighth aspect of the invention, the dies 1 and 2 according to any of the second to sixth aspects are applied to a metal injection molding machine.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a method for applying a powder release agent in a metal injection molding machine and a metal injection molding machine according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic cross-sectional configuration diagram of an injection molding machine showing an embodiment of the present invention, showing a configuration in which a supply passage and a discharge passage are blocked, and FIG.
FIG. 2 is a configuration diagram showing a state in which a supply path and a discharge path are opened by a shutoff pin in FIG. 1.

Reference numeral 1 denotes a fixed-side mold having a concave mold surface corresponding to the product surface on one side. The fixed-side mold 1 is fixedly arranged on a fixed-side mold plate 8 of an injection molding machine. To be done. Reference numeral 2 denotes a movable-side mold in which a mold surface corresponding to the product surface on the other side is provided in a protruding manner. The movable-side mold 2 is a movable-side mold plate 9 via a slide base and a movable-side mounting plate. It is fixed and arranged.

When the facing surfaces of the fixed-side mold 1 and the movable-side mold 2 come into contact with each other, the mold surface of the fixed-side mold 1 and the mold surface of the movable-side mold 2 allow the product to be manufactured. A mold cavity 3 corresponding to the shape is formed.

A heating nozzle 4 is provided at the tip of a heating cylinder (not shown) for holding the molten metal. The fixed mold 1 includes a sprue portion 5, a manifold portion 6 and a nozzle portion 7.
A hot runner consisting of the hot runner is heated to about 600 ° C.
The metal molding material injected from is always kept in a molten state,
The injection is made from the nozzle portion 7 into the mold cavity 3.

An ejector pin 10 is provided in the movable mold 2 so as to communicate with the mold cavity 3, and a product is taken out by extruding an extruding rod connected to the ejector pin 10.

According to the present invention, the stationary mold 1 is provided with a powder release agent supply passage 11 and a discharge passage 12 at one end and the other end in the longitudinal direction of the die cavity 3 provided therein. A powder supply means for supplying a powder release agent is communicated with the supply path 11, and an exhaust means for exhausting the inside of the mold cavity 3 is communicated with the discharge path 12, so that after the mold is clamped. Immediately before injecting the molten metal, a powder release agent is introduced from the supply passage 11 to be applied in the mold cavity 3, and exhausted from the discharge passage 12 arranged at the other end. By using a powder mold release agent, unlike a water-soluble mold release agent, since the mold is applied in a closed state, the mold release agent is not applied to unnecessary portions, and mist such as water vapor is generated. It does not occur, the surface of the mold is not cooled, and the release agent application time can be shortened. The details will be described below.

The movable mold 2 is provided with concave overflow grooves 13 and 14 which communicate with the mold cavity 3 and the supply passage 11 and the discharge passage 12, respectively. The powder release agent is introduced through the overflow groove 13 on the supply path 11 side,
The gas is exhausted through the overflow groove 14 on the discharge path 12 side.

The fixed mold 1 is arranged between the supply passage 11 and the overflow groove 13 and the discharge passage 12 and the overflow groove 14 to open / close the supply passage 11 and the discharge passage 12, respectively. Is provided. The opening / closing means is arranged in the fixed side mold, and shutoff pins 15 and 16 slidable in the longitudinal direction of the mold cavity 3 and hydraulic cylinders 17 and 18 for driving and controlling the sliding of the shutoff pins 15 and 16. Consists of.

That is, the shutoff pins 15 and 16
1 is moved to the mold cavity 3 side as shown in FIG.
The communication between 1 and the discharge path 12 is cut off. On the other hand, as shown in FIG. 2, when the shutoff pins 15 and 16 are moved in the direction away from the mold cavity 3 side, the communication between the overflow grooves 13 and 14 and the supply passage 11 and the discharge passage 12 is established. It will be released. When applying the powder release agent, the hydraulic cylinders 17 and 18 open the shutoff pins 15 and 16 for a predetermined time when receiving a signal from the limit switch that the mold cavity 3 is sealed. Driven to.

A powder supply device 22 is connected to the supply passage 11 side by a connection hose 23, and the powder release agent stored in the powder supply device 22 is connected by compressed air to the connection hose 23.
It is conveyed to the mold cavity 3 side via.

A valve 19 is provided between the exhaust hose 24 and the vacuum tank 20 to shut off and open the discharge passage 12 by opening and closing the valve. The valve 19 is opened by driving the shutoff pin 16, and at the same time, the valve is opened by an electric signal from the limit sensor. A vacuum tank 20 and an exhaust pump 21 are sequentially connected to the valve 19, and when the valve 19 is opened, the exhaust pump 2
1, the inside of the mold cavity 3 is maintained at a high degree of vacuum through the vacuum tank 20.

The coating operation of the powder release agent will be described below. One cycle of injection molding is roughly divided into a mold clamping and powder release agent application process, an injection process, a cooling and product removal process.

First, in the step of applying the powder mold release agent, the movable side mold plate 9 is brought into contact with the fixed side mold plate 8 and the mold is clamped to fix the fixed mold die 1.
And the movable mold 2 are brought into contact with each other to form a mold cavity 3. When the mold cavity 3 is sealed, the hydraulic cylinder 1
The shut-off pins 15 and 16 are driven by 7 and 18 to move away from the mold cavity 3.

As a result, the supply passage 11 and the discharge passage 12 are opened. On the supply path 11 side, the powder release agent stored in the powder supply device 22 is conveyed by compressed air and introduced into the mold cavity 3 through the connection hose 23, the supply path 11, and the overflow groove 13. To be done. The discharge path 12 side is
At the same time as the shutoff pin 16 is driven, the valve 19 is opened by an electric signal from the limit sensor,
The pressure inside the mold cavity 3 is reduced by driving the exhaust pump 21 which is a pressure reducing device. Therefore, the solid powder release agent supplied from the powder supply device 22 is sucked into the mold cavity 3 through the supply passage 11 and the overflow groove 13, and the inside of the mold cavity 3 is powdered. Filled with release agent. Then, the powder mold release agent in the mold cavity 3 is applied by colliding with the mold surface forming the mold cavity 3. On the other hand, the powder release agent remaining in the mold cavity 3 is sucked and discharged to the pressure reducing device side through the overflow groove 14, the discharge path 12, and the connection hose 24.

After the powder release agent is supplied by the powder supply device 22 for a preset time, the supply passage 11 and the discharge passage 12 are moved to the mold cavity 3 side by the operation of the hydraulic cylinders 17 and 18. Moved and blocked. After this, the hot nozzle is heated, the temperature of the hot nozzle rises from the base temperature and reaches the set temperature, and then the signal is sensed, and the molten metal previously injected from the heating nozzle 4 into the hot runner is applied to the nozzle portion. It is injected into the mold cavity 3 via 7. The injected molding material fills the mold cavity 3 and at the same time flows into the overflow grooves 13 and 14. Since the supply passage 11 is communicated with the mold cavity 3 through the overflow groove 13, the powder mold release agent accumulated excessively does not flow into the mold cavity 3. On the other hand, since the exhaust port 12 side also communicates with the mold cavity 3 through the overflow groove 13,
Excessively deposited powder release agent deposited in the vicinity of the exhaust port 12 will not be caught in the mold cavity 3.

After the completion of injection, when the set heating time has elapsed, the heating body of the hot nozzle is stopped and the temperature is lowered to the base temperature. In parallel with this, when the set cooling time has expired, the molds 1 and 2 are opened, the ejector pin 10 causes the product in the mold cavity 3 to protrude from the mold surface, and the product is taken out and ejected. The pin 10 returns to complete one cycle of injection molding.

[0033]

According to the first and second aspects of the present invention, with this structure, the fixing is performed immediately after the mold clamping and immediately before the molten metal injection.
It is arranged on the side mold and communicates with one end of the mold cavity (3).
And perpendicular to the moving direction of the movable mold (2)
So as to open communication with the direction, the supply passage is bent arranged to powder mold releasing agent from (11), by introducing the powder mold releasing agent, gold
Mold on the movable side that communicates with the other end of the mold cavity (3)
To communicate with the opening in the direction perpendicular to the moving direction of (2)
In addition, since the gas is discharged from the discharge path (12) that is bent and arranged, the powder mold release agent supply path and / or the exhaust port can be provided in accordance with the product shape. The agent can be applied to the mold cavity reliably and efficiently.

According to the third aspect of the invention, the movable side mold is
Overflow grooves that communicate with the supply path and / or the discharge path are formed, and the powder release agent is introduced through the overflow groove on the supply path side and exhausted through the overflow groove on the discharge path side. Since the passage or the exhaust port is communicated with the mold cavity through the overflow groove, the powder mold release agent that has accumulated excessively will not flow into or be caught in the mold cavity. The quality of the product can be improved.

According to a fourth aspect of the present invention, it is arranged between the supply passage and the overflow groove on the supply passage side and / or between the discharge passage and the overflow groove on the discharge passage side to shut off the supply passage and / or the discharge passage. With the configuration including the opening / closing means that can be opened, the molten metal does not enter the supply passage and / or the discharge passage, and the powder release agent can be effectively applied.

In the invention according to claim 5, the hydraulic cylinder is arranged in a direction perpendicular to the moving direction of the movable side mold.
Since it is arranged in the fixed side mold, the thickness of the whole mold does not increase, and the mold can be downsized.

According to the sixth aspect of the invention, since the suction valve that can be opened and closed is disposed on the discharge passage side, even if the sealing performance is not sufficient only by the opening / closing means, the valve can be opened / closed sufficiently. Depressurization can be carried out.

According to the seventh aspect of the present invention, since the hot runner is arranged in the stationary mold, the supply passage or the discharge passage is provided regardless of the position of the nozzle portion of the hot runner. It is particularly preferable because it is possible.

The invention according to claim 8 is applied to a metal injection molding machine, which is particularly preferable.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional configuration diagram of a metal injection molding machine showing an embodiment of the present invention, and is a configuration diagram showing a state in which a supply path and a discharge path are blocked by a shutoff pin.

FIG. 2 is a configuration diagram showing a state in which a supply path and a discharge path are opened by a shutoff pin in FIG.

FIG. 3 is a schematic sectional configuration diagram of a conventional metal injection molding machine.

[Explanation of symbols]

1 Fixed mold 2 Movable mold 3 Mold cavity 4 heating nozzle 11 supply path 12 discharge path 13,14 Overflow groove 15,16 Shut-off pin 17, 18 hydraulic cylinder 19 valves 21 Exhaust pump 20 vacuum tank 22 Powder feeder

Continuation of the front page (56) Reference JP 2001-138025 (JP, A) JP 2001-113352 (JP, A) JP 2001-105112 (JP, A) JP 2000-343194 (JP, A) JP 62-127150 (JP, A) JP 11-293429 (JP, A) JP 9-277007 (JP, A) JP 9-241784 (JP, A) JP 8-215822 ( JP, A) JP 8-90197 (JP, A) JP 7-323360 (JP, A) JP 7-60426 (JP, A) JP 5-31563 (JP, A) JP HEI 3-161155 (JP, A) Patent 3101618 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22D 17/20 B22D 17/22 B22C 9/06 B22C 23/02

Claims (8)

(57) [Claims] 1. A fixed mold (1) and a movable mold (2)
In the mold release agent application method of applying the powder mold release agent into the mold cavity (3) formed by the method described above, the mold cavity (3) is disposed on the stationary mold immediately before the molten metal injection after mold clamping. ), And a supply path (11) for the powder mold releasing agent, which is bent and arranged so as to communicate with one end of the movable mold (2) and to communicate with the opening in a direction perpendicular to the moving direction of the movable mold (2)
Bends so as to introduce the powder mold release agent and communicate with the other end of the mold cavity (3), and to communicate with the opening in the direction perpendicular to the moving direction of the movable mold (2). A method for applying a powdery mold release agent, characterized in that the gas is exhausted from a discharge path (12) provided in such a manner. 2. A fixed mold (1) and a movable mold (2)
A mold cavity (3) formed by both molds and having a powder mold release agent applied thereto, wherein the mold cavity (1) is provided with a mold cavity (3). 3) A powder release agent supply path (11) and a powder release agent discharge path (12) are connected to one end and the other end of (3), and are opened and communicated in a direction perpendicular to the moving direction of the movable mold (2). In the mold cavity (3), a powder supply means is provided, which is bent and formed, communicates with the supply path (11) and supplies a powder release agent, and communicates with the discharge path (12). Evacuation means for evacuating the mold is provided. Immediately before the molten metal injection after mold clamping, the powder mold releasing agent is introduced from the supply channel (11) to apply the powder mold releasing agent into the mold cavity (3), and the discharge channel ( 12) A die characterized by being exhausted more. 3. The movable mold (2) communicates with one end of the mold cavity (3) and a supply path (11), and / or the other end of the mold cavity (3) and a discharge path (12). The mold according to claim 2, further comprising an overflow groove (13, 14) communicating with the mold. 4. The supply path (11) and the supply path (11)
Side overflow groove (13) and / or the discharge channel (12) and the discharge channel (12) side overflow groove (1)
The mold according to claim 2 or 3, further comprising an opening / closing means which is disposed between 4) and is capable of blocking and opening the supply passage (11) and / or the discharge passage (12). 5. The opening / closing means is arranged in a fixed side mold (1), and slides in a direction perpendicular to the moving direction of the movable side mold (2), whereby the supply passage (11) and And / or shut-off pin (1) that can open / close the discharge path (12)
The mold according to claim 4, characterized in that it comprises a hydraulic cylinder (17, 18) for driving the shut-off pin (15, 16). 6. The mold according to claim 2, wherein a valve (19) capable of blocking and opening the discharge passage (12) is arranged on the discharge passage (12) side. . 7. The mold according to any one of claims 2 to 6, wherein a hot runner is arranged on the stationary mold (1). 8. The mold according to claim 2, wherein the mold is applied to a metal injection molding machine.