JPH0216848Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a suction casting device, and more particularly to a suction casting device that suction-fills molten metal into a product cavity by reducing the pressure inside the product cavity through a mold.

[Conventional technology]

A so-called suction casting method is known in which the pressure of a product cavity in a mold is reduced, molten metal is sucked into the product cavity through a sprue of the mold, and the molten metal is solidified within the product cavity while maintaining the reduced pressure state. According to such a suction casting method, the molten metal is gently introduced into the product cavity by the pressure difference between the pressure acting on the liquid surface of the molten metal and the pressure inside the product cavity, and the reduced pressure state is maintained during solidification. .
Therefore, it is possible to produce a casting free from casting defects such as poor water flow and slag inclusion.

By the way, in this suction casting method, the mold is transported to the upper part of the melting furnace, the mold is lowered until the sprue of the mold is immersed in the molten metal, and then the mold is raised after the suction casting, and then the mold is moved to the post-processing position. It is necessary to transport it. At this time, green sand molds, shell sand molds, ceramic shell molds, plaster molds, etc. that are commonly used as molds have low strength, so the molds may be damaged if they are moved in a complicated manner as described above. Moreover,
Since the mold is mechanically strained, there is a natural limit to shortening the casting cycle time, that is, shortening the transportation time other than the casting time.

In addition, in the conventional suction casting method, the negative pressure necessary to suck up the molten metal by suction into the product cavity of the mold must be created in the product cavity of the mold, so the pressure difference between the inside and outside of the mold is generated. The stress causes the mold to float, which may cause the mold to break, or create a gap between the sprue (stoke) and the container body for reducing the pressure in the product cavity of the mold, making it impossible to suck the molten metal.

In order to solve this problem, the following measures have been taken to fix the mold and prevent it from floating.

(a) A method of fixing the mold by filling the space between the mold and the inner wall of the container (decompression chamber) with an insulating material such as ceramic fiber.

(b) A method of fixing a mold by shaping at least a portion of the inner wall of the container into a shape that follows the outer shape of the mold.

(c) A method of fixing the mold by pressing the top of the mold using the repulsive force of a spring installed at the upper end of the inner wall of the container.

[Problem that the invention attempts to solve]

However, method (a) has the problem of extremely low productivity, and method (b) lacks versatility because it cannot be used when the mold shape, especially the mold height, changes. In method (c), if the spring strength is too strong, the mold may be damaged; conversely, if the spring strength is weak,
If the stress generated by the pressure difference between the inside and outside of the mold is strong, problems such as the mold floating will occur, and although this method is not as bad as method (b), it is still lacking in versatility. Furthermore, the spring itself gradually wears out due to repeated casting operations, and especially when exposed to high temperatures, the deterioration is further accelerated, necessitating replacement after long-term use.

[Means for solving problems]

The above problem is solved by the suction casting device of the present invention which will be described below.

That is, the suction casting device of the present invention accommodates a mold,
It has a container body and a lid member that support and form a substantially sealed space, and the container body is provided with a hole through which the sprue of the mold can pass, and either the container body or the lid member has a hole that allows the sprue of the mold to pass through. is a suction casting device equipped with a port for decompression, and the lid member includes a mold holding member that can be raised and lowered toward the top of the mold, and a first mold holding member that prevents the mold holding member from falling off. A stopper is attached,
In addition, a second stopper is provided that penetrates the lid member and fixes the mold holding member in a predetermined position.

[Effect]

According to the suction casting apparatus of the present invention, a mold is first housed in a container body, and the sprue portion (stalk) of the mold is made to protrude from a hole provided at the bottom of the container body. At the next step, cover the container body with the lid member. At this time, the mold holding member comes into contact with the top of the mold. In this state, the mold is supported in a predetermined position by bringing the second stopper into contact with the mold holding member.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

(First Example) A first example of the present invention will be described based on FIG.

Here, FIG. 1 is a sectional view of a suction casting apparatus according to a first embodiment of the present invention.

In the figure, 1 is a sealable container (decompression chamber) used in the suction casting method, and is composed of a container body 2 in the shape of a box or a cylindrical body with a bottom, and a lid member 3 that covers the opening of the container body 2. Become. A hole 4 is provided approximately at the center of the bottom of the container body 2, and is integrated with a mold 5 made of mold material such as foundry sand or plaster.
Alternatively, a stalk 6 corresponding to a sprue portion of a separately formed mold 5 is inserted. A flange portion 2a is provided at the upper end of the container body 2, and corresponds to the peripheral portion of the lid member 3, thereby forming a substantially sealed space. An O-ring 7 as a sealing material is interposed between the flange portion 2a and the peripheral portion of the lid member 3.

The lid member 3 consists of a central protrusion 3a and a surrounding flat plate part 3b. A support member 9 that supports the mold holding member 8 is attached to the space within the protrusion 3a downward from the upper wall surface of the protrusion 3a. A first stopper 10 is provided at the tip of the support member 9 to prevent the mold holding member 8 from falling. The mold holding member 8 is slidably inserted into the support member 9, and the tip portion 8a that directly presses the mold 5 is formed of ceramic fiber or the like so as not to damage the mold 5.

Further, a hole 11 is provided on the side of the protrusion 3a, and a second stopper 1 is provided toward the mold holding member 8.
2 is attached so that it can move forward and backward. An O-ring 13 as a sealing material is interposed between the second stopper 12 and the side of the protrusion 3a.
This second stopper 12 is driven by an appropriate means such as a cylinder or a screw. Note that a taper is provided at the contact portion of the mold holding member 8 with the second stopper 12, and the shape of the tip of the second stopper 12 is made into a shape corresponding to the taper.

Further, a port 14 is formed in the flat plate portion 3b of the lid member 3 for connection to a pressure reducing means such as a vacuum pump (not shown).

Next, using the suction casting device according to this example,
The procedure for carrying out the suction casting method will be explained.

First, open the container (vacuum chamber) 1 and mold 5.
is placed in this container 1 with the stalk 6 protruding from the hole 4. Next, the lid member 3 is placed on the container body 2, and the container 1 is sealed. At this time, the mold holding member 8 supported by the first stopper 10 at the lower end of the support member 9 hits the upper end of the mold 5 on the way as the lid member 3 is lowered and does not move any further. However, the lid member 3 further descends until it becomes integral with the container body 2. During this time, the support member 9 integrated with the lid member 3 also descends together with the lid member 3.

When the container body 2 and the lid member 3 are integrated, the second stopper 12 is advanced toward the mold holding member 8 and pressed to fix the mold holding member 8. Next, the entire container 1 is moved, and the tip of the stalk 6 of the mold 5 is immersed in the molten metal stored in a molten metal storage container (not shown). Subsequently, the pressure reducing means is activated to remove the container 1 through the port 14 of the container 1.
The internal pressure is reduced, thereby reducing the pressure in the product cavity 15 of the mold 5 to about -400 to -600 mmHg through the mold 5, and the molten metal is sucked and injected into the product cavity 15. In this case, in order to improve the efficiency of the casting operation, the pressure reduction in the container 1 by the pressure reduction means may be started before the tip of the stalk 6 is immersed below the surface of the molten metal. Next, the hot water introduced into the product cavity 15 is solidified while maintaining the reduced pressure inside the container 1. When the pressure reduction is stopped after the molten metal in the product cavity 15 has solidified, the unsolidified molten metal sucked up into the stalk 6 of the mold 5 falls from the lower end of the stalk 6 into a molten metal storage container (not shown). After the molten metal in the product cavity 15 has completely solidified, the container 1 is opened and the cast mold 5 is taken out. Then, the mold is broken down to obtain a product.

During the above casting operation, the container 1 is transported to a predetermined position by a clamp device (not shown) having a claw portion that engages with the flange portion 2a of the container body 2.

According to the suction casting apparatus of this embodiment, the mold 5 is fixed while being lightly pressed by the mold pressing member 8, so that floating of the mold can be prevented without damaging the mold 5.

In addition, the work of fixing the mold is as simple as placing the lid member 3 on the container body 2 and then moving the second stopper 12 to fix the mold holding member 8, which improves work efficiency and improves productivity. Improves sex.

(Second Embodiment) Next, a second embodiment of the present invention will be described based on FIG. 2.

Here, FIG. 2 is a sectional view of a suction casting apparatus according to a second embodiment of the present invention.

The suction casting apparatus of the second embodiment differs from the first embodiment in that a through hole 16 is provided in a protrusion 3a provided at the center of the lid member 3;
6, a mold holding member 8 having a tip 8a made of a cushioning material at one end to prevent damage to the mold and a first stopper 10 to prevent falling at the other end is slidably inserted. An O-ring 17 as a sealing material is interposed between the protrusion 3a and the mold holding member 8. The rest is substantially the same as the first embodiment.

Note that since the functions and effects are substantially the same as those of the first embodiment, their explanations will be omitted.

Although a specific embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and includes various embodiments within the scope of the claims for utility model registration. It is.

[Effect of idea]

As described above, according to the suction casting apparatus of the present invention, it is possible to prevent the mold from floating in a simple manner without damaging the mold, and productivity is greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a suction casting apparatus according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a suction casting apparatus according to a second embodiment of the present invention. 1... Container (decompression chamber), 2... Container body,
2a...flange part, 3...lid member, 3a...protrusion part, 3b...flat plate part, 4, 11...hole, 5...
Mold, 6...Stoke (gate part), 7, 13, 1
7... O-ring, 8... Mold holding member, 9...
Support member, 10...first stopper, 12...second stopper, 14...port, 15...product cavity, 16...through hole.

Claims (1)

[Claims for Utility Model Registration] It has a container body and a lid member that accommodate and support a mold and form a substantially sealed space, and the container body is provided with a hole through which the sprue of the mold can pass. Further, the suction casting device is provided with a depressurizing port on either the container body or the lid member, and the lid member includes a mold holding member that can be raised and lowered toward the top of the mold; Suction casting characterized in that a first stopper is attached to prevent the mold holding member from falling off, and a second stopper is provided that penetrates the lid member and fixes the mold holding member in a predetermined position. Device.