JP2532215Y2 - Pressure pin cooling device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pressure casting apparatus such as a die casting machine, which cools a pressure pin inserted into a molten metal in a mold cavity so as not to be overheated. Related to a cooling device.

[0002]

2. Description of the Related Art In a vertical die-casting machine, for example, a molten metal is injected into cavities of upper and lower dies which have been clamped, and the molten metal is cooled and solidified to obtain a product. Injecting the molten metal, the molten metal does not spread to all corners of the cavity, so a dense product may not be obtained, and shrinkage cavities may be formed due to solidification shrinkage of the molten metal, resulting in lower product quality Therefore, this type of injection device is generally provided with a pressurizing pin, and pressurizes the molten metal by injecting the pressurized pin into the cavity immediately before or immediately after the injection of the molten metal into the cavity is completed. A so-called feeder that removes only the volume of the pin is performed.

[0003] As a pressing pin device of this kind, for example, one disclosed in Japanese Patent Publication No. 2-40415 filed by the present applicant has disclosed a driving device in a rod hole passing through the center of a movable mold. A pressure pin which moves forward and backward is provided to allow the pressure to enter the molten metal in the cavity, and the one disclosed by Japanese Patent Application No. 2-17265 filed by the present applicant is disclosed in A pressurizing cylinder and a pressurizing pin which moves forward and backward by the pressurizing cylinder are provided in a rod hole penetrating through the center of the plunger which enters from below, and this penetrates into the molten metal in the cavity.

In this type of pressure pin device, the pressure pin is inserted into a high-temperature molten metal,
Since the molten metal is seized on the sliding surface and the surface is deteriorated or damaged, a water-cooled cooling device is attached to the pressing pin. Conventionally, this cooling device is a device in which a hollow water pipe is passed through a water hole provided through the center of a pressurizing pin. After returning from the other end of the pipe, it returns to the water supply side through a gap between the peripheral surface of the water pipe and the water hole, and the pressure pin is cooled by this reciprocation. As an alternative to this method, two chambers are separated by a flat plate so that a forward path having a semicircular cross section and a return path having a semicircular cross section are formed in the water flow hole, and cooling is performed from one end of the forward path. It is also conceivable to cool the water by making a U-turn at the other end of the outward path and returning to the water supply side via the return path.

[0005]

However, in such a conventional cooling device for a pressure pin, if the cross-sectional area of the gap through which the cooling water passes is not sufficiently large, the passage is blocked and the water does not circulate. However, it is necessary to increase the cross-sectional area of the passage, and as a result, there is a problem that the diameter of the pressure pin becomes large and the size of the apparatus cannot be reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a cooling device for a pressing pin which can obtain a sufficient cooling effect even if the pressing pin has a small diameter.

[0007]

According to the present invention, in order to achieve the above object, the driving device is driven forward and backward by a driving device such that a tip end is inserted into and pulled out of a molten metal in a mold cavity supported by a mold. that the pressure pin, provided a heat pipe for cooling is transmitted through the shaft core portion of the pressure pin on the tip portion of the low temperature by extending the cooling to the tip portion from the cooling portion of the pressure pin, the pressure Place the cooling part of the pin in the longitudinal direction of the heat pipe.
The heat pipe that extends to the bottom and supports the base end of the heat pipe
The Ip press serves as a partition and the inside is divided in the radial direction.
And the heat pipe retainer has one of the cooling sections.
The communication hole that connects the space and the other space
A plurality is formed at intervals in the longitudinal direction, and
And a drain in the other space.
Communicated.

[0008]

[Operation] Immediately before or immediately after the injection of the molten metal into the cavity is completed, the tip of the pressure pin is caused to enter the molten metal filled in the cavity. Hot water is done. At this time, when cooling water is passed through the pressure pin, the low temperature due to cooling is transmitted to the tip of the pressure pin by a heat pipe having a good thermal conductivity, so that the pressure pin entering the molten metal is cooled. The tip is cooled and does not overheat.

[0009]

1 to 3 show an embodiment of a cooling device for a pressing pin according to the present invention, and FIG. 1 shows a cross section of a part of a mold of a vertical die casting machine and a pressing pin according to the present invention. FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a sectional view taken along the line III-III of FIG. 2. In this embodiment, a pressure pin is mounted on a side of a stationary mold for casting an engine block. An example is shown. In the figure, a cavity 2 is formed at a joint between a fixed mold 1 and a movable mold (not shown) above the fixed mold which is on the near side of FIG. 1, and an injection (not shown) is formed in the cavity 2. The molten metal 3 is injected and filled by the cylinder.

A sleeve 4 with a flange formed in a cylindrical shape is fitted in a sleeve hole 1a provided on a side portion of the fixed mold 1, and a water pool 4a as an inner hole of the sleeve 4 is formed. The cavity 3 is filled with the molten metal 3. And
The pool 4a is tapered so that the diameter gradually decreases from the opening end on the cavity 2 side toward the bottom of the hole. Reference numeral 5 denotes a core which becomes a hollow part in a cast product.

The sleeve 4 is provided with a pin hole 4b continuous with the pool 4a, and the pin hole 4b is provided with a pressure pin 7 provided in a pressure pin device indicated by reference numeral 6 as a whole.
The small-diameter portion 7a is fitted by being driven forward and backward by a fluid pressure cylinder as a driving device (not shown) so that the distal end portion is inserted into and removed from the molten metal 3 in the pool 4a. The pressure pin 7 has a small-diameter portion 7 having a cylindrical shape with a bottom and a concave end surface.
a and a large-diameter portion 7b which is also formed in a cylindrical shape with a bottom and whose bottom is connected to a drainage portion by a hose (not shown ). The inside of the large diameter portion 7b is related to the present invention.
The pressure pin 7 forms a cooling unit. In the large diameter portion 7b of the pressure pin 7, a hollow pipe 8 having one end fixed to the bottom of the large diameter portion 7b and connected to a cold water source (not shown) by a hose is provided. It extends to the central part of and is stored. At the distal end of the hollow pipe 8, a heat pipe retainer 9 is formed to be slightly slidable on a base 9a and supported . The heat pipe retainer 9 has the base 9
a, and are formed at an interval in the axial direction of the large diameter portion 7b.
It is integrally formed with the pipe pressing portion 9c with several water passing holes 9b which are formed at the base of the pipe holding portion 9c
Slidably fits into the inner hole of the small diameter portion 7a of the pressure pin 7.
The base end of the combined heat pipe 10 is fitted.
The water holes 9b constitute the communication holes according to the present invention.
Further, the heat pipe retainer 9 is arranged so that the axis of the large diameter portion 7b is
Extending in the longitudinal direction of the heat pipe 10,
As shown in FIG. 3, the inside of the large diameter portion 7b is divided in the radial direction.
It is configured to be a partition. Heat pipe retainer
9, one of the spaces in the large diameter portion 7b divided by
A space communicates with the hollow pipe 8 and the other space is
It communicates with the water department. Heat pipe retainer 9 like this
With such a configuration, the inside of the large diameter portion 7b of the pressure pin 7
The longitudinal direction of the heat pipe 10 by the heat pipe retainer 9
A cold water passage extending to This cold water passage is
Since the structure is such that cold water flows through the plurality of water holes 9b,
Heat pipe 1 without stagnation in the large diameter portion 7b.
Contact the base part of 0 over a wide area in the longitudinal direction
You .

The tip of the heat pipe 10 is positioned at the bottom of the inner hole of the small diameter portion 7a by the resilience of a compression coil spring 11 interposed between one end of the hollow pipe 8 and the base 9a of the heat pipe retainer 9. It is urged to be pressed. The heat pipe 10 is a conventionally well-known product that is commercially available, and generally has a hollow bar-shaped depressurized and sealed container in which a wick for liquid reflux is housed. Have.

The operation of the pressure pin device configured as described above will be described. When the plunger tip of the injection cylinder (not shown) advances, the molten metal 3 in the injection sleeve is pushed and injected into the cavity 2. Immediately before or immediately after the end of injection filling of the molten metal 3, a fluid pressure cylinder (not shown) is operated to advance the pressure pin 7 connected to the piston rod via a coupling, and the tip end thereof is indicated by a chain line in the figure. As shown, since the molten metal 3 enters the molten metal 3 filled in the cavity 2 and the pool 4a, the molten metal 3 is removed by an amount corresponding to the entering volume of the pressure pin 7, and the hot water is fed.

At this time, a pump as a cold water source is operated to supply cold water to the hollow pipe 8 via a hose, advance the inside of the hollow pipe 8, and then press down the pipe holding portion 9 c of the heat pipe holding 9 and the pressure pin 7. Of the large diameter portion 7b. Then, the cold water flows between the heat pipe 10 and the inner periphery of the large diameter portion 7b of the pressure pin 7 through the water hole 9b and the space above the heat pipe retainer 9 while cooling the latter half of the heat pipe 10. After that, the water is discharged from the drain hole at the bottom of the large diameter portion 7b and discharged to the drain portion by a hose. The low temperature of the rear half of the heat pipe 9 cooled by the cooling water as described above is transmitted to the front end of the heat pipe 9 by the heat pipe 9 having extremely good heat conduction, and is transmitted to the front end of the pressure pin 7. The entrance to the pool 4a is cooled. Therefore, even if the heat of the molten metal 3 is transmitted to the distal end of the pressure pin 7, it does not overheat. In addition, the pressurizing pin 7 has a cooling part housed in the large-diameter part 7b, but the heat pipe 10 as the cooling part is housed in the small-diameter part 7a. Absent.

In this embodiment, the inner peripheral surface of the pool 4a is tapered so as to expand toward the opening end, so that the mold release agent is easily attached and the heat retention is good. The adhesion of the solidified layer to the inner peripheral surface of the metal is reduced. Further, by forming the tip end surface of the pressing pin 7 in a concave shape,
The solidified layer adhering to the inner peripheral surface of the pool 4a is
Since the cutting is performed at the circular edge portion at the tip, the solidified layer is not pushed into the cavity, and no crack is generated at a portion following the open end of the sleeve 4.

In this embodiment, an example is shown in which the pressure pin device is mounted on the side of the mold, but it may be provided at the center of the movable mold, the injection plunger, or the like.

[0017]

As is apparent from the above description, according to the present invention, in the cooling device for the pressing pin, the tip is driven to be inserted into and pulled out of the molten metal in the mold cavity supported on the mold side. A pressure pin driven forward and backward by the device, and a heat pipe that penetrates the shaft of the pressure pin, extends from the cooling part of the pressure pin to the tip, and transmits the low temperature by cooling to the tip to cool. With this arrangement, the tip cooling portion of the pressure pin can be made smaller in diameter, so that the size of the mold can be reduced, and the cooling portion using cooling water can be stored in the larger diameter portion of the pressure pin. In addition, the cross-sectional area of the gap through which the cooling water passes can be made sufficiently large, so that the passage is not blocked and the water does not circulate, and the function of the pressure pin is improved. Also support the base end of the heat pipe.
The cooling part of the pressure pin is divided in the radial direction
The heat pipe retainer has one space in the cooling section.
The communication hole that communicates with the other space
At intervals in the direction.
Connect the cold water source to the space and the drain to the other space
The heat pipe inside the cooling section of the pressure pin.
Therefore, a cold water passage extending in the longitudinal direction of the heat pipe is formed.
Is done. In this cold water passage, cold water flows through a plurality of communication holes.
Chilled water may stay in the cooling section.
A wide area in the longitudinal direction at the base end of the heat pipe
Contact over Therefore, the base end of the heat pipe
The side part can be efficiently cooled.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a part of a mold and a pressing pin of a vertical die casting machine embodying the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed mold 2 Cavity 3 Melt 4 Sleeve 6 Pressure pin device 7 Pressure pin 7a Small diameter part 7b Large diameter part 10 Heat pipe

Claims (1)

(57) [Scope of request for utility model registration] A pressure pin supported on a mold side and driven forward and backward by a driving device so that a tip portion is inserted into and pulled out of a molten metal in a mold cavity; it provided a heat pipe for cooling is transmitted from the cooling section of the pressurizing pin at the tip of the cold by extending cooling the tip
In addition, the cooling part of the pressure pin
The heat pipe that extends to the bottom and supports the base end of the heat pipe
The Ip press serves as a partition and the inside is divided in the radial direction.
And the heat pipe retainer has one of the cooling sections.
The communication hole that connects the space and the other space
A plurality is formed at intervals in the longitudinal direction, and
And a drain in the other space.
Cooling system pressure pin, characterized in that communicated.