JPH07115151B2 - Low pressure casting method and low pressure casting apparatus - Google Patents

Description

TECHNICAL FIELD The present invention relates to a die casting method and a casting apparatus using a turntable.

(Prior Art) In a casting method using a mold, generally, a cavity formed in the mold is filled with a molten metal, cooled and solidified, and then released.

As a casting method or casting apparatus using such a die, those disclosed in Japanese Examined Patent Publication No. 56-8703 and Japanese Utility Model Publication No. 61-82746 are known.

The casting apparatus disclosed in Japanese Examined Patent Publication No. 56-8703 is one in which a plurality of molds are provided on a turntable, and pouring of metal into the cavity of the mold and release of the casting are performed simultaneously. Japanese Utility Model Application Laid-Open No. 61-82746 discloses a method of directional solidification by applying a temperature gradient to a mold.

(Problems to be Solved by the Invention) In the one disclosed in Japanese Patent Publication No. Sho 56-8703, it is shown that the casting work and the mold release work are performed at separate work stations. When casting using, when cleaning the mold and applying the mold release agent, and further when pressurizing the molten metal in the cavity, this pressurizing work should be done at the same station as other work. However, the cycle time becomes long and it cannot be expected to improve work efficiency.

In addition, since the mold has a much higher thermal conductivity than the shell and sand molds, the solidification shrinkage of the casting becomes partially uneven, and a part of the casting is restrained by the mold, causing hot cracking and deformation of the mold.・ Causes wear. This cannot be sufficiently prevented by directional coagulation alone.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a turntable on which a maximum of four dies are placed at 90 ° intervals, and at 90 ° intervals along the rotation direction of the turntable. A first station for cleaning the placed mold and applying a release agent, a second station for low-pressure casting of the melt into the mold cavity, and a third station for pressurizing the melt in the cavity, A low-pressure casting device is constructed from the fourth station for releasing the casting.

(Function) The mold on the turntable is exposed to the first station to clean the mold and apply the release agent, and then the turntable is rotated 90 ° to expose the mold to the second station. , Low-pressure casting was performed there, and a turntable was installed.
Rotate 90 ° to expose the die to the third station, pressurize the molten metal in the cavity there, then rotate the turntable 90 ° to expose the die to the fourth station, and take out the casting there. .

(Example) Below, the Example of this invention is described based on an accompanying drawing.
In addition, casting of a knuckle arm of an automobile is shown as an example.

1 is a plan view of a casting apparatus according to the present invention, and FIG. 2 is a first view.
3 is a sectional view of the second station, FIG. 4 is a sectional view of the third station, and FIG. 5 is a sectional view of the fourth station.

The casting apparatus rotatably supports the turntable 1 on the base 3 via the shaft 2 in a horizontal plane, and the turntable 1 moves on the base 3 via the rollers 4 in response to a signal from the control device.
° It is designed to rotate intermittently.

Further, stations S1 to S4 for work are arranged at intervals of 90 ° along the rotation direction of the turntable 1. Here, S1 is the first station for cleaning the mold and applying the release agent, S2 is the second station for low-pressure casting of the molten metal, S3 is the third station for pressurizing the molten metal in the cavity, and S4 is the casting. This is the fourth station for releasing the mold.

Further, four molds 5 are provided on the turntable 1 at intervals of 90 °. The mold 5 is composed of a fixed mold 5a and a movable mold 5b which moves along a guide rod.
A cavity surface 6 is formed on the opposing surface of b, and a mold release plate that is moved forward and backward by a cylinder unit or the like outside the molds 5a and 5b.
7, 7 are arranged, and pay-out pins 8 ... Which extend through the molds 5a, 5b and extend into the cavity 6 are fixed to these release plates 7, 7.

Further, a concave portion 9 is formed in a portion of the upper surface of the turntable 1 on which the movable die 5b slides, and a slide plate 11 that moves forward and backward by a cylinder unit 10 is provided in the concave portion 9.
The cavity 6 is advanced to this slide plate 11.
The molten metal supply hole 6a and the runner 12 formed in the turntable 1 are communicated with each other, and as shown in FIG. 4, a hole 13 is provided to block the communication between the molten metal supply hole 6a and the runner 12 in a retracted state. ing.

Next, the devices arranged in the first to fourth stations S1 to S4 will be described. First, the first station S1 is provided with a cleaning / releasing agent coating device 14 that can move up and down facing between the fixed mold 5a and the movable mold 5b in the mold open state, and the second station S2 is located below the turntable 1. Pouring furnace 15 and melting furnace on the side of this
16 is provided, and the molten metal M is placed in the cavity 6 in the furnace lid 17 of the pouring furnace 15.
A stalk 18 for supplying the molten metal M is provided vertically, a molten metal supply pipe 19 is provided between the pouring furnace 15 and the melting furnace 16, and the molten metal M filled in the cavity 6 is provided at the third station S3. A pressure device 20 for applying pressure is provided. Instead of the pressurizing device 20, the molten metal M may be pressurized by a feeder. Further, in the fourth station S4, the chucking device 22 for picking up the casting 21 from the mold 5 in the mold open state and the hole of the slide plate 11
A thrusting device (25) for dropping the metal block (23) solidified in (13) into a bucket (24) below is provided.

A die casting method performed by using the above casting apparatus will be described below. In the present invention, the work is performed in the first to fourth stations S1 to S4 at the same time, but for the sake of clarity, the explanation will be given using the mold 15 at the position of the first station S1 as a starting point.

First, at the first station S1, as shown in FIG.
The mold fixed mold 5a and movable mold 5b are opened to clean the surface of the cabty 6 by the cleaning / release agent applying device 14 and apply the release agent. Then, the turntable 1 is rotated 90 °, and the fixed mold 5a and the movable mold 5b are clamped as shown in FIG. 3, and then the molten metal M in the pouring furnace 15 is filled into the cavity 6 through the stalk 18. . Here, as the molten metal, cast iron components,
Use a steel component or Al alloy component. Specifically, a molten metal having the components shown in the following [Table] is prepared.

Then, after the molten metal M is filled in the cavity 6, the turntable 1 is rotated again by 90 ° and the upper opening of the cavity 6 is closed by the pressurizing device 20 of the third station S3 as shown in FIG. Further, the slide plate 11 is retracted to close the molten metal supply hole 6a of the cavity 6 and pressurize the molten metal in the cavity 6. Here, when the pressurizing circuit and the cooling circuit are incorporated in the mold itself, the molten metal in the portion of the molten metal supply hole 6a is rapidly cooled and solidified by using the cooling circuit so that the molten metal supply hole 6a is closed. You may

Next, the turntable 1 is rotated by 90 ° again, the mold 5 is positioned at the fourth station S4, and the casting 21 is released from the cavity 6 by the pin 8 and the casting 21 by the chucking device 22 as shown in FIG. Take up.

Here, the mold release timing is performed when the surface temperature of the casting is between the eutectic line (about 1150 ° C.) and 350 ° C. directly below when the molten metal of the cast iron component is used. This is because when the surface temperature of the casting falls below 800 ° C, the casting adheres to the die due to solidification shrinkage of the casting, causing deformation and wear of the die, and also causing hot cracking of the casting. .

For the same reason, the mold release timing when using the melt of the steel component is performed between the solidus line (about 1250 ° C) and 250 ° C immediately below it, and when the melt of the Al alloy component is used. It is carried out between the eutectic line (about 850 ° C) and 230 ° C directly below.

(Effects of the Invention) As described above, the present invention has a turntable on which a maximum of four dies are placed at 90 ° intervals, and dies arranged at 90 ° intervals along the rotation direction of the turntable. A first station for cleaning and applying a release agent, and a second station for low-pressure casting the molten metal into the cavity of the mold,
A low-pressure casting apparatus is composed of a third station for pressurizing the molten metal in the cavity and a fourth station for releasing the casting, and in particular, low-pressure casting is performed at the second station and pressurization is performed at the next third station. The cycle time can be shortened compared to the conventional technology in which low pressure casting and pressurization are performed in the same station.
Greatly improved work efficiency can be expected.

[Brief description of drawings]

1 is a plan view of a die casting apparatus according to the present invention, FIG. 2 is a sectional view of a first station, FIG. 3 is a sectional view of a second station, FIG. 4 is a sectional view of a third station, FIG. 5 is a sectional view of the fourth station. In the drawing, 1 turntable, 5 is a mold, 6 is a cavity, 6a is a molten metal supply hole, 11 is a slide plate, 15 is a pouring furnace, 20 is a pressurizing device, 21 is a casting, S1 is the first station,
S2 is the second station, S3 is the third station, and S4 is the fourth station.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B22D 17/32 Z 18/04 M

Claims (2)

[Claims] 1. A first method for cleaning a mold and applying a release agent.
A station, a second station for low-pressure casting of the molten metal into the mold cavity, a third station for pressurizing the molten metal in the cavity, and a fourth station for releasing the casting in the turntable rotation direction. Along the 90 ° intervals, the mold on the turntable is exposed to the first station to clean the mold and apply the release agent, and then the turntable is rotated by 90 °. The mold is exposed to the second station, low-pressure casting is performed there, and the turntable is rotated by 90 ° to expose the mold to the third station, where the molten metal in the cavity is pressurized. A low-pressure casting method characterized in that a turntable is rotated by 90 ° so that the die faces the fourth station and the casting is taken out therefrom. 2. A turntable on which a maximum of four dies are placed at 90 ° intervals and along the direction of rotation of the turntable.
The first station for cleaning the molds arranged at 90 ° intervals and applying the release agent, the second station for low-pressure casting of the melt into the mold cavity, and the pressurization of the melt in the cavity A low-pressure casting machine consisting of three stations and a fourth station for releasing the casting.