JP4391491B2 - Pressing device for tunnel core punching pin and casting method using tunnel core punching pin pressurizing device - Google Patents

Description

  The present invention relates to a pressurizing cylinder for a tunnel core punching pin, and more particularly, to a tunnel core punching pin provided with a cored pin that also serves as a pressure pin for preventing the occurrence of a molten metal in a cavity in a casting process. The present invention relates to a pressurizing cylinder.

  2. Description of the Related Art Conventionally, a press device for a tunnel core casting pin in which a cast pin is provided so as to be movable to a molten metal injection position, a pressurization position, and a retracted position is known by the applicants as disclosed in Patent Document 1. Yes. Patent Document 1 discloses a pressurizing device having a configuration in which a stop position of a tunnel core can be controlled in three stages of a molten metal injection position, a pressurizing position, and a retracted position by a single pressurizing cylinder.

Moreover, as shown in Patent Document 2, a mold apparatus provided with a bush for holding a tunnel core casting pin is disclosed. In this apparatus, the bush is arranged in the mold so that the front end surface of the bush is flush with the cavity surface of the mold.
JP-A-8-90199 Japanese Patent Laid-Open No. 10-43851

  However, in the pressurization apparatus shown in Patent Document 1, since the pressurization cylinder has a three-chamber structure of the first chamber to the third chamber, the control is complicated, and the pressurization cylinder is a custom-made product having a complicated structure. It was. Further, as shown in Patent Document 2, by attaching the bush to the mold, the cast pin can be easily held, but if the casting is repeated, the tip of the bush is deformed by thermal expansion or molten metal pressure. The surface may recede from the cavity surface. When the front end surface of the bush retreats from the cavity surface, the molten metal was inserted and solidified, which could hinder product removal.

  Therefore, the present invention is capable of controlling the stop position of the tunnel core in three stages, that is, a molten metal injection position, a pressurizing position, and a retracted position with a simple configuration, and that suppresses the occurrence of troubles in die casting of the cast product. An object of the present invention is to provide a pressing device for a core pin and a casting method using the same.

  In order to solve the above problems, the present invention provides a cylinder, a tunnel core casting pin 8 that is driven by the cylinder to pressurize the molten metal in the mold cavity 20a, and is driven by the cylinder. And a bushing 11 arranged around the core core pin 8 and slidably holding the core core pin 8 slidably. The first core 4 capable of moving the core casting pin 8 and the bush 11 between the molten metal injection position and the retracted position, and the tunnel core casting with the bush 11 disposed at the molten metal injection position. The pin 8 has a second cylinder 6 which can move between the molten metal injection position and the pressurizing position, and the end of the bush 11 projects into the mold cavity 20a at the molten metal injection position. Providing pressure device 1 of the tunnel core core pin are.

  Moreover, in order to solve the said subject, the casting method which casts using the pressurization apparatus 1 of the said tunnel core casting pin is provided.

  According to the press device for a tunnel core pin according to claim 1, since the cylinder for driving the tunnel core pin is constituted by the first cylinder and the second cylinder, two commercially available chambers are provided. A cylinder having a structure can be used as the first cylinder and the second cylinder. Therefore, since it is sufficient to control the first cylinder and the second cylinder individually in order to drive the tunnel core casting pin, it is possible to easily perform the control related to the driving of the tunnel core casting pin.

  When the molten metal is injected, the bush holding the tunnel core casting pin is moved to the molten metal injection position in the cavity by the first cylinder, and the tip portion protrudes from the cavity surface. Thereby, it is suppressed that a molten metal inserts between the cavity surface of a metal mold | die and the front-end | tip surface of a bush, and is solidified, Therefore, die cutting of a product can be performed easily.

  According to the casting method using the tunnel core casting pin pressurizing device according to claim 2, since the casting is performed using the tunnel core casting pin pressurizing device, the control of the tunnel core casting pin is performed. Is easy, and even when the mold is released, the molten metal can be prevented from being solidified by being inserted between the cavity surface of the mold and the front end surface of the bush. It is possible to stably cast cast products.

  A casting method using a tunnel core casting pin pressurizing device and a tunnel core casting pin pressurizing device according to an embodiment of the present invention will be described with reference to FIGS. A pressurizing apparatus 1 shown in FIG. 1 is installed in a casting mold 20. The casting mold 20 includes a holder 21 and a die 22. A cavity 20a is defined inside the die 22 on the right side of the die 22 on the paper surface of FIG. 1, and a cavity surface 22A is defined on the inner surface of the die 22 defining the cavity 20a. The holder 21 is formed with a hole 21a into which a later-described pressure bush coupling holder 9 can be inserted, and the die 22 has a diameter substantially the same as the outer diameter of the later-described pressure bush 11, and the hole 21a A hole 22a located on the same axis is formed.

  The pressurizing device 1 is mainly composed of a flange 2, a support column 3, a core extracting cylinder 4, a pressurizing cylinder 7, a pressurizing pin 8, and a pressurizing bush 11. A pair of support columns 3 are provided, supported by a holder 21 on one end side by screws 3A, and a flange 2 is provided on the other end side. A core extraction cylinder 4 as a first cylinder is fixed to the flange 2 by a bolt 4A.

  The core extraction cylinder 4 includes a piston (not shown) inside. This piston (not shown) can reciprocate in the direction from the flange 2 toward the holder 21. Further, in the core extraction cylinder 4, the extraction core joint 5 is connected to a rod of a piston (not shown) at a position on the holder 21 side with the flange 2 interposed therebetween.

  Between the flange 2 and the holder 21 and between the pair of support columns 3 and 3, a pressurizing holder 6 in which a pressurizing cylinder 7 which is a second cylinder is fixed with a bolt 7A is arranged. The pressure holder 6 is connected to the drawing core joint 5. Therefore, the pressure holder 6 and the pressure cylinder 7 can be reciprocated in the direction from the flange 2 toward the holder 21 by the core extraction cylinder 4 via the extraction core joint 5. The core extraction cylinder 4 and the pressure cylinder 7 are both commercially available pressure cylinders, and the core extraction cylinder 4 and the pressure cylinder 7 constitute the cylinder of the present invention.

  At the holder 21 side position of the pressure holder 6, a pressure bush connection holder 9 extending toward the holder 21 side is fixed by a plate 6 </ b> A constituting the pressure holder 6. A pressure pin 8 that is a tunnel core punching pin is disposed inside the pressure bush connection holder 9. The pressure pin 8 is connected to a rod of a piston (not shown) of the pressure cylinder 7. Yes. Since the piston (not shown) of the pressure cylinder 7 can reciprocate in the direction from the flange 2 toward the holder 21, the pressure pin 8 can reciprocate in the direction from the flange 2 toward the holder 21 with respect to the pressure holder 6. It has become. Further, the pressure pin 8 has a step portion 8A on the base end side thereof, and when the pressure pin 8 moves to the holder 21 side, the step portion 8A and the pressure bush connection holder 9 are brought into contact with each other. The amount of movement of the pressure pin 8 is regulated.

  As shown in FIG. 2, a pressure bush 11 is fixed to the tip of the pressure bush connection holder 9 by pressure bush connection nuts 10A and 10B. The pressure bush 11 is formed in a cylindrical shape, and the tip end portion of the pressure pin 8 is disposed inside. The inner diameter of the cylindrical portion of the pressure bush 11 and the tip portion is configured to be approximately the same as the outer diameter of the pressure pin 8. Therefore, the pressure pin 8 is slidably held in the pressure bush 11.

  Further, since the pressure bush 11 is connected to the pressure bush connection holder 9 by the pressure bush connection nuts 10A and 10B, when the pressure bush 11 deteriorates due to use, the pressure bush connection nuts 10A and 10B. It is possible to easily replace the pressure bush 11 by removing. Further, the pressure bush connecting holder 9 can be easily replaced by removing the plate 6A.

  The operation of the pressure device 1 having the above-described configuration and the casting method using the pressure device 1 will be described. FIG. 1 shows an initial state of casting, and shows a state of the pressurizing device 1 when a molten metal such as an aluminum alloy supplied into a sleeve (not shown) is injected (a molten metal injection position). At the molten metal injection position, the core drawing cylinder 4 moves a piston (not shown) to the holder 21 side, and moves the drawing core joint 5 and the pressure holder 6 connected to the drawing core joint 5 to the holder 21 side. To do. In this state, the tip end portion of the pressure bush 11 connected to the pressure holder 6 protrudes into the cavity 20a from the cavity surface 22A.

  Further, the pressure cylinder 8 is disposed at a position where the tip of the pressure pin 8 slightly protrudes from the pressure bush 11 and the step portion 8 </ b> A is separated from the pressure bush connection holder 9.

  This state is maintained, the molten metal is injected by a plunger tip (not shown), and the molten metal is filled into the cavity 20a. As described above, since the tip of the pressure bush 11 protrudes into the cavity 20a from the cavity surface 22A, the molten metal is inserted between the cavity surface 22A of the casting mold 20 and the tip surface of the pressure bush 11 and solidifies. It is suppressed.

  The pressurizing device 1 shifts to a pressurizing operation when the filled molten metal starts to solidify. As shown in FIG. 3, the pressure pin 8 is moved by the pressure cylinder 7 and moved to a position (pressure position) where the tip portion of the pressure pin 8 further protrudes from the tip of the pressure bush 11. At this time, the core drawing cylinder 4 is not particularly driven, and at least the pressure holder 6 may be held at the same position as the molten metal injection position.

  The tip of the pressurizing pin 8 driven by the pressurizing cylinder 7 in accordance with this pressurizing operation pressurizes the molten metal that has started to solidify, and replenishes the melted part with the molten metal, thereby preventing the generation of the shrinkage nest. The pressurization is performed until the stepped portion 8A of the pressurizing pin 8 contacts the pressurizing bush connection holder 9.

  After the pressurizing operation is finished, as shown in FIG. 4, the pressurizing pin 8 is from the pressurizing position to the position where the stepped portion 8 </ b> A is separated from the pressurizing bush connection holder 9 and the same position as the molten metal injection position. Moving.

  Then, as shown in FIG. 5, the pressurizing holder 6 is moved to the flange side position (retreat position) by the core extracting cylinder 4. As the pressure holder 6 moves to the retracted position, the tip end portion of the pressure bush 11 moves from the position protruding from the cavity surface 22A into the hole 22a. Thereafter, the casting mold 20 is opened, and the product is die-cut. In this case, since the generation of the molten metal solidified between the cavity surface 22A of the casting mold 20 and the front end surface of the pressure bush 11 is suppressed, it is possible to easily perform die cutting.

  The cylinder for driving the pressure pin 8 is composed of a core extraction cylinder 4 and a pressure cylinder 7. The core extraction cylinder 4 and the pressure cylinder 7 can be individually controlled. Therefore, the control related to the driving of the pressure pin 8 can be easily performed.

  Therefore, by using the pressurizing apparatus 1, it is possible to stably cast a cast product with reduced shrinkage by suitably applying pressure.

  The tunnel core casting pin pressure device and the casting method using the tunnel core casting pin pressure device according to the present invention are not limited to the above-described embodiments, but within the scope described in the claims. Various modifications and improvements are possible. For example, in this embodiment, the tip of the pressure pin 8 slightly protrudes from the tip of the pressurizing bush 11 at the molten metal injection position. As long as the tip of the bush 11 protrudes from the cavity surface 22 </ b> A into the cavity 20 a, the tip of the pressure pin 8 may not protrude from the tip of the pressure bush 11.

  The tunnel core casting pin pressurizing device and the tunnel core casting pin pressurizing device of the present invention are useful in the field of casting such as die casting.

Sectional drawing in the molten metal injection position of the pressurization apparatus which concerns on embodiment of this invention. The fragmentary sectional view which shows the bush periphery in the molten metal injection position of the pressurization apparatus which concerns on embodiment of this invention. Sectional drawing in the pressurization position of the pressurization apparatus which concerns on embodiment of this invention. Sectional drawing after the pressurization operation | movement of the pressurization apparatus which concerns on embodiment of this invention. Sectional drawing in the retracted position of the pressurization apparatus which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressurization apparatus 2 Flange 3 Support | pillar 3A Screw 4 Cylinder extraction cylinder 4A Bolt 5 Extraction core joint 6 Pressure holder 6A Plate 7 Pressure cylinder 7A Bolt 8 Pressure pin 9 Pressure bush connection holder 10A, B Pressure Bushing nut 11 Pressure bush 20 Casting die 20a Cavity 21 Holder 21a Hole 22 Die 22A Cavity surface 22a Hole

Claims (2)

A cylinder,
A tunnel core punching pin driven by the cylinder to pressurize the molten metal in the mold cavity;
A press device for a tunnel core punching pin comprising: a bush driven by the cylinder and disposed around the tunnel core punching pin and slidably holding the tunnel core punching pin. ,
The cylinder includes a tunnel cylinder core pin and a first cylinder capable of moving the bush between a molten metal injection position and a retracted position, and the tunnel core in a state where the bush is disposed at the molten metal injection position. A second cylinder capable of moving the cast pin between the molten metal injection position and the pressurizing position;
A pressurizing device for a tunnel core die pin, wherein an end of the bush protrudes into the mold cavity at the molten metal injection position.   A casting method, wherein the casting is performed using the pressurizing device for a tunnel core casting pin according to claim 1.

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