JPH0628792B2 - High pressure casting equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high-pressure casting apparatus used for so-called loose metal forging, and particularly prevents an initial set layer formed on the inner surface of an injection sleeve from entering the mold cavity. The present invention relates to a high-pressure casting device equipped with a gate core.

(Prior Art) Recently, a high-pressure casting apparatus is generally used to produce a high-quality cast product such as an A1 alloy without casting defects. This high-pressure casting apparatus forms a cavity between an upper die and a lower die. ,
The molten metal in the injection sleeve disposed below the lower mold is pressurized and supplied into the cavity by a plunger, and is pressurized at a high pressure of about 1000 kg / cm ^{2 for} casting.

When the molten metal is supplied into the injection sleeve or the molten metal in the injection sleeve is pushed up by the plunger during the high-pressure casting, the molten metal contacting the inner surface of the sleeve having a relatively low temperature is cooled and the material has a fragile thickness. When an initial solidified layer of several tens of μm is formed and the molten metal in the injection sleeve is pressurized and supplied into the cavity at a low speed, the initial solidified layer peels off and enters the cavity, which affects the quality of the cast product. It is considered to have an adverse effect.

Therefore, the applicant of the present application has filed a previous application (Actual Development Sho 60-1131).
No. 55), a pair of gate cores that advance from both sides and narrow the gate part to a slightly smaller diameter are provided at the gate part of the boundary between the molding cavity and the injection sleeve side, and the molten metal in the injection sleeve is supplied under pressure into the cavity. At the same time, a molten metal forging die apparatus was proposed in which the gate core prevents the initial solidified layer from entering the cavity.

By the way, in order to form a heat insulating layer that generally suppresses the formation of the initial solidification layer, even when the mold device is used or not, an aqueous solution containing graphite particles is mixed on the inner surface of the mold and the inner surface of the injection sleeve. Spray application is performed.

(Problems to be Solved by the Invention) In the high-pressure casting apparatus equipped with the gate core, if the mold release agent is applied to the inner surface of the mold after the cast product is taken out, the mold and the injection sleeve are heated to a considerably high temperature. As a result, moisture evaporates and a heat insulating layer of graphite particles is formed on the inner surface of the mold and the inner surface of the injection sleeve.

However, the mold release agent that has flowed down from the inner surface of the mold to the surface of the gate core enters the sliding gap of the gate core and remains liquid, and the water contained in the liquid mold release agent evaporates during casting. When expanded into the mold cavity, it may cause a casting defect such as a blister.

(Means for Solving Problems) A high-pressure casting apparatus according to the present invention has a gate core for preventing an initial solidified layer generated in an injection sleeve from entering the cavity at a gate for introducing a molten metal into a mold cavity. A high-pressure casting apparatus provided so as to be retractable is provided with an air blower for blowing pressurized air to the gate core or the gate core sliding hole in a state where a mold release material is applied to the inner surface of the mold cavity.

(Operation) In the high-pressure casting apparatus according to the present invention, since the pressurized air is blown to the gate core or the gate core sliding hole by the dead blow device in the state where the mold releasing agent is applied to the inner surface of the mold cavity as described above, The release agent adhering to the surface of or the release agent attached to the gate core sliding hole does not scatter, and the release agent does not remain in the liquid state in the gate core sliding hole.

(Effect of the Invention) According to the high-pressure casting apparatus according to the present invention, as described above, the air blower blows air into the gate core or the gate core sliding hole to cause the mold release agent to enter or remain in the gate core sliding hole. Therefore, it is possible to surely prevent the casting defect from occurring in the cast product due to the release agent in the gate core sliding hole.

(Example) Hereinafter, the Example of this invention is described based on drawing.

Since a high-pressure casting apparatus for high-pressure casting (molten metal forging) of a cast product such as an A1 alloy under a high-pressure condition is a well-known apparatus, the detailed description of the entire structure will be omitted, and the main part related to the present invention will be described with reference to the first section. This will be described with reference to FIG. 2 and FIG.

As shown in FIG. 1, the lower molding die 1 is fitted and fixed in the central tapered hole of the lower fixed die 1A supported by a frame (not shown), and hydraulic pressure is applied to the upper surfaces of the lower molding die 1 and the fixed lower die 1A. The upper mold 2 that is driven up and down by the cylinder is pressed and fixed in a close contact, and a casting cavity 3 is formed inside the molding lower mold 1 and the upper mold 2.

A mold sleeve 6 is disposed below the molding plate mold 1 with a gate core guide 5 for mounting the gate core 4 interposed therebetween, and a mold sleeve 6 is provided at a central portion between the gate core guide 5 and the mold sleeve 6. Has a vertical injection hole 7 communicating with the lower end of the casting cavity 3, and an injection sleeve 8 having the same inner diameter as the injection hole 7 and a predetermined length is disposed below the mold sleeve 6. The upper end portion of the injection sleeve 8 can be engaged with the engagement portion 6 a of the mold sleeve 6.

A plunger 9 is slidably mounted in the injection sleeve 8, and the injection sleeve 8 is vertically driven by a hydraulic cylinder to an injection position shown by a solid line in FIG. 1 and a lowered position shown by a virtual line. The plunger 9 is also driven up and down by a hydraulic cylinder.

Then, the injection sleeve 8 is swayed between a pouring position which is inclined about 30 degrees laterally by a hydraulic cylinder and a vertical position which is vertically raised with a pivotal support portion on the lower end side as a center of rotation in a state where the injection sleeve 8 is lowered to the lower position. It is free to move.

Here, the basic operation during casting is as follows.

The plunger 9 is kept at a position lower than the upper end of the injection sleeve 8 by a predetermined height, the injection sleeve 8 is tilted to the pouring position with the injection sleeve 8 in the lowered position, and the molten metal is poured into the injection sleeve 8 by the water heater. After pouring the molten metal, and then returning the injection sleeve 8 to the vertical position, the injection sleeve 8 is raised to the injection position and engaged with the mold sleeve 6, and in this state, the plunger 9 is raised at a low speed to release the injection sleeve 8 The molten metal inside is injected and supplied from the injection hole 7 into the casting cavity 3, and is pressurized by the plunger 9 to about 1000 kg / cm ^{2 for} casting.

By the way, when the molten metal comes into contact with the inner surfaces of the injection sleeve 8 and the die sleeve 6 at a relatively low temperature, the molten metal is rapidly cooled to form an initial solidified layer having a weak metal structure and a thickness of several tens of μm.

To prevent the initial solidified layer from entering the casting cavity 3 when pouring the molten metal into the casting cavity 3,
A pair of right and left plate-shaped gate cores 4 are slidably mounted in the gate core sliding holes 10 of the gate core guide 5, and each gate core 4 is moved by a hydraulic cylinder 11 in an imaginary line in an advanced position and in a solid line in a retracted position. The position can be switched to the on position.

The pair of gate cores 4 relatively come close to the injection hole 7 from both left and right sides at the advanced position to close the outer peripheral portion of the injection hole 7, and at the retracted position to the left and right from the outer periphery of the injection hole 7. It is supposed to retreat.

Here, after removing the cast product from the casting cavity 3, a mold releasing agent in which graphite particles are mixed in water is spray-coated on the inner surface of the casting cavity 3, and the mold releasing agent is applied to the gate core sliding hole 10. Easy to enter, this gate core sliding hole 1
In order to remove the release agent adhering to the inner surface of No. 0 by air blow, the following air blow device is provided.

That is, as shown in FIGS. 1 and 2, when the pair of left and right gate cores 4 is switched to the retracted position, each gate core 4 is
3 each on the left and right with appropriate spacing in the front-back direction corresponding to the vicinity of the inner end of the
At the position of the position, the gate core guide 5 and the mold sleeve 6 are vertically provided with six air supply holes 12 in total, and these air supply holes 12 are provided with a pressurized air supply source 14 via a pipe line 13. The solenoid valve of the solenoid valve 15 is connected to the control box 16.

Then, in order to change the direction of the pressurized air supplied from the pressurized air supply source 14 to the air supply hole 12 through the pipe line 13 toward the ejection hole 7, the gate core 4 facing the upper end opening of the air supply hole 12 is changed. An air guide recess 1 is provided on the lower surface side near the inner end.
7 is recessed from the lower surface side.

Next, the operation of casting with the above high-pressure casting apparatus will be described.

After the upper mold 2 is moved upward and the gate core 4 is switched to the retracted position and then the cast product is taken out, the mold release agent is spray-coated on the inner surfaces of the cavities of the upper mold 2 and the molding lower mold 1.
At this time, since spray coating is applied to the lower casting mold 1 from above, the release agent also adheres to the inner surface of the gate core sliding hole 10.

When the opening / closing valve 15 is opened immediately after the spray application is completed, the pressurized air is supplied from the air supply hole 12 to the gate core sliding hole 1
The main flow of the air blow flows along the lower surface of the sliding hole 10 and the sub-flow of the air blow flows along the upper surface of the sliding hole 10, so that the air blows out The release agent attached to the inner surface of the hole 10 is scattered by the air blow.

After removing the release agent in the sliding hole 10 in this way, the gate core 4 is switched to the advanced position, and high-pressure casting is performed by the procedure already described.

During this casting, when the molten metal is poured into the casting cavity 3 by the plunger 9, the initial solidified layer formed on the inner surface of the injection sleeve 8 and the inner surface of the injection hole 7 of the mold sleeve 6 is moved upward by the plunger 9. Although it is pushed up slowly, since the gate core 4 is in the advanced position and protrudes above the outer peripheral portion of the injection hole 7, the initial solidified layer collides with the gate core 4 and is crushed, and the direction of the cavity 3 is changed.
It becomes difficult to intrude into the inside, and even if it intrudes, it will be dispersed in a wide range and finely, so that the quality of the cast product will not be adversely affected.

Since the mold release agent does not remain in the gate core sliding hole 10 during the casting, the water in the mold release agent does not evaporate,
High quality castings can be manufactured.

As a modified example of the above-described embodiment, as shown in FIGS. 3 and 4, when the mold release agent is applied after the gate core 4 is switched to the advanced position, the inner end of the gate core 4 is applied from above. In order to prevent the mold release agent from entering the gate core sliding hole 10 by scattering the mold release agent flowing down by air blow, for example, four sets of air nozzles 18 are provided below the mold sleeve 6 at the inner end of the gate core 4. After spraying the release agent, air blow is performed before the injection sleeve 8 is raised to the injection position.

As described above, by air-blowing the gate core sliding hole 10 or the gate core 4 after applying the release agent,
Prevent the release agent from remaining in the gate core sliding hole 10,
It is possible to reliably prevent the occurrence of casting defects such as blisters due to the evaporation of the release agent moisture remaining in the gate core sliding hole 10.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a main part of a high-pressure casting apparatus, FIG. 2 is a sectional view taken along line II-II of FIG.
FIG. 3 is a view equivalent to FIG. 1 of the modified example, and FIG. 4 is FIG.
It is a line sectional view. 1.1A lower mold, 2 upper mold, 3 casting cavity, 4 gate core, 5 gate core guide, 6
… Mold sleeve, 7 …… Injection hole, 8 …… Injection sleeve,
9 ... Plunger, 10 ... Gate core sliding hole, 11 ...
... hydraulic cylinder, 12 ... air supply hole, 13 ... pipeline,
14 ... Pressurized air supply source, 15 ... Open / close valve, 16 ... Control box, 17 ... Air guide recess, 18 ...
… Air nozzle.

Continuation of the front page (72) Inventor, Tetsuhiro Tanaguchi, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) Reference JP 62-203658 (JP, A)

Claims (1)

[Claims] 1. A high-pressure casting apparatus in which a gate core for introducing molten metal into a mold cavity is provided with a gate core for preventing an initial solidified layer generated in an injection sleeve from entering the cavity, the mold cavity being provided in the mold cavity. A high-pressure casting apparatus comprising an air blow device for blowing pressurized air to the gate core or the gate core sliding hole in a state where a release agent is applied to the inner surface.