JP2768726B2 - Casting mold and casting method using the casting mold - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting mold and a casting method using the casting mold, and in particular, a plug member capable of closing a runner communicating a hot water supply port and a casting cavity. And a casting method in which a heating member and a cooling member are incorporated in the plug member, and a casting method using the casting mold.

[Prior art and problems to be solved]

Generally, when performing injection molding, compression molding, transfer molding, etc. of a resin molded product having a hollow portion, a molding material such as resin is filled in a state where a core matching the hollow portion is disposed in a molding cavity. After molding a primary molded article containing a core, there is a method of obtaining a molded article having a hollow portion by removing only the core from the primary molded article.

As a core used for this, a low-melting alloy made of a material capable of melting and removing only the core by heating to a predetermined temperature after molding a primary molded article containing the core is known.

Generally, a casting mold used for casting a core made of such a low melting point alloy forms a casting cavity with a pair of contacting / separable casting dies, and a low melting point casting material is formed in the casting cavity. It has a hot water supply port through which the alloy material can be supplied via the runner. When casting using such a casting mold, first, the molten low melting point alloy material is cast from the hot water supply port through the runner through the casting hole. After the filling is completed, the low melting point alloy material in the casting cavity is cooled and solidified, and then the casting mold is opened and taken out, and the runner portion communicating with the casting cavity formed on the surface of the casting is formed. The burr was removed to obtain a low melting point alloy core.

However, in the casting mold as described above, when the bore area of the runner is small, the low melting point alloy material is easily solidified in the runner when the casting cavity is filled with the low melting point alloy material, The filling of the melting point alloy material takes a long time and the production efficiency of the core is poor, and when the bore area of the runner is increased, the filling time of the low melting point alloy material into the casting cavity is shortened. However, when the low-melting alloy core, which is a casting, is removed from the casting mold after casting, the joint area between the runner and the casting cavity is large, and it is difficult to cut the joint to remove the casting. With
The burr, which is the cut portion of the runner formed on the surface of the casting, becomes large, and it takes time to remove the burr,
There was a problem that post-processing became difficult.

Further, it is necessary to provide a runner communicating with the casting cavity in a place where cooling of the casting mold is most difficult, and there is a problem that there is a restriction on a design position of the runner in the casting mold.

The present invention solves the above-mentioned problems of the prior art, and can increase the caliber area of the runner, increase the degree of freedom in its design position, facilitate the work of taking out a casting, and improve the casting performance. An object of the present invention is to provide a casting mold and a casting method using the casting mold, which can easily perform a deburring operation on a surface of an article and can greatly improve casting efficiency.

[Means for solving the problem]

In order to achieve the above object, a casting mold according to the present invention forms a casting cavity with a first casting mold and a second casting mold that are in contact with and separated from each other. A casting mold for filling a low melting point alloy material from a supply port,
In at least one of the casting mold and the second casting mold, a through hole that opens to the runner is formed, and in the through hole,
A plug member containing a heating member and a cooling member is provided so as to be movable, and the runner can be closed by the movement of the plug member. Is heated by a built-in heating member, and in a state where the runner is held at the open position, the low melting point alloy material is filled into the casting cavity from the hot water supply port via the runner. When the cooling of the low melting point alloy material is started, the plug member is moved to a position for closing the runner, and is cooled by a built-in cooling member.

[Action]

The present invention employs the above configuration and means, while filling the low-melting alloy material into the casting cavity, holds the plug member in a position where the runner is opened and heats the plug member so that the low-melting point in the runner is maintained. The solidification of the alloy material is prevented, and after the filling is completed, the plug member is moved to a position where the runner is closed and cooled to promote solidification of the low melting point alloy material in the runner. The cut portion can be formed in advance on the melting point alloy material.

〔Example〕

 Hereinafter, embodiments of the present invention shown in the drawings will be described.

1 and 2 show an embodiment of a casting mold according to the present invention. The casting mold includes a first casting mold 1 and a second casting mold 2 which are separated from each other. A groove 3 is formed on the dividing surface 2a of the second casting mold 2 to open upward, and a hot water supply opening is formed on the upper surface of the casting mold formed by the first casting mold 1. 4 and a runner 5 connected to the casting cavity 3 continuously therefrom.

Further, the second casting mold 2 has a through hole 6 having one end opened to the runner 5 and the other end opened to the opposite side of the first casting mold and penetrating the second casting mold 2. The diameter of the through hole 6 is substantially equal to the diameter of the runner 5.
A plug member 7 having a heating member 9 and a cooling member 10 built therein.
Are movably arranged.

The plug member 7 includes a main body 8 made of a good heat transfer material formed in a column shape substantially matching the through hole 6, and a main body 8.
Cooling member 10 consisting of a cooling pipe buried in the center of the
And a heating member 9 composed of a pair of heaters embedded outside the cooling member 10. The cooling member 10 can be cooled by supplying cooling water from outside, and the heating member 9 is a lead wire. It is connected to a power supply (not shown) via 11 and can be heated.

That is, the plug member 7 is cooled by flowing cooling water through the cooling member 10 by an operation from the outside.
Further, heating by applying a voltage to the heating member 9 via the lead wire 11 can be switched respectively.

Further, the first casting mold 1 is provided with a thermocouple 12 which penetrates the casting mold 1 and reaches the runner 5, so that the temperature inside the runner 5 can be detected.

FIG. 3 shows a state in which the plug member 7 moves in the through hole 6 to open and close the runner 5, and FIG. 4 shows a state in which the plug member 7 is separated from the second casting mold 2. FIG. 2A shows a view from the side where the tip surface 7a of the plug member 7 is filled with the runner 5 of the second casting mold 2 when the low melting point alloy material is filled.
The runner 5 is opened in a state in which the runner 5 coincides with the surface forming the.

After the completion of the filling of the low melting point alloy material, the front end surface 7a of the plug member 7 is in a position where it abuts the dividing surface 1a of the first casting mold 1 and closes the runner 5.

In order to cast a low melting point alloy core using the casting mold configured as described above, first, the first and second casting molds 1 and 2 are brought into contact with each other to close the mold, and the plug member 7 is closed.
Is heated by applying a voltage to the heating member 9 through the lead wire 11, and is held at the position shown in FIG. 2, that is, the position where the runner 5 is opened.

In this state, the low melting point alloy material melted from the hot water supply port 4 is put into the casting cavity 3 via the runner 5.

At this time, the plug member 7 for opening the runner 5 is kept in a heated state until the filling is completed, and the low melting point alloy material passing through the runner 5 is kept in a molten state.

Then, after the filling of the low-melting point alloy material is completed, cooling of the casting cavity 3 of the casting mold is started, and before and after the start of the cooling, the tip end surface 7a of the plug member 7 is moved to the first position. To move until it comes into contact with the dividing surface 1a of the casting mold 1 to close the runner 5 and stop the heating of the heating member 9 incorporated in the plug member 7, and supply cooling water to the cooling member 10 for cooling. Switch to.

After the solidification of the low melting point alloy material in the casting cavity 3 is completed, the first and second casting molds 1 and 2 are opened, and a low melting point alloy core, which is a casting, is extruded with an unillustrated extrusion pin or the like. Is removed from the casting mold, and burrs and the like formed on the surface are removed to obtain a low melting point alloy core.

In each of the above steps, the temperature of the low melting point alloy material in the runner 5 is detected by the thermocouple 12, and the heating / cooling of the plug member 7 is switched accordingly.

In the present invention as described above, when the casting cavity 3 is filled with the low melting point alloy material, the plug member 7 is located at the position for opening the runner 5 and the runner 5 is opened.
The inside is held in a heated state by the plug member 7, and before and after the filling of the casting cavity 3 is completed and solidification starts, the runner 5 is closed and cooled by the plug member 7. The diameter of the casting hole 3 can be greatly reduced, and the filling time of the low melting point alloy material into the casting cavity 3 can be greatly reduced. In addition, the hot water supply port 4 and the runner 5 communicating therewith are provided. Since the position can be provided in a place where the casting mold is easily cooled, the selection range of the mounting position of the runner 5 is increased, the degree of freedom of the design of the casting mold is increased, and further, the low melting point alloy which is the obtained cast product is used. When the child is taken out, the low melting point alloy material has been cut in advance by the plug member 7 closing the runner 5, so that
The work of removing the casting cavity 3 becomes easy, and the post-processing of the work of removing the burrs, which are the cut portions formed on the surface of the casting, is also simplified.

Therefore, it is possible to shorten the filling time of the low-melting-point alloy material, take out the cast product, and perform post-processing such as deburring, greatly shorten the casting process of the low-melting-point alloy core, and enable mass production. .

In the present invention, the plug member 7 is formed in a cylindrical shape, but the shape is not limited to this, and the plug member 7 may be formed in a square rod shape as long as the runner 5 can be closed.

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to increase the caliber area of the runner that fills the casting cavity with the low-melting alloy material, thereby greatly reducing the filling time of the low-melting alloy material into the casting cavity. It is possible to shorten the length of the casting, and the range of choice of the location of the hot water supply port and the runner communicating therewith is increased, so that the degree of freedom in designing the casting mold is increased. When the core is taken out, the low melting point alloy material is cut in advance by a plug member that closes the runner, so that the work of taking out from the casting cavity is facilitated, and the cutting formed on the surface of the casting is facilitated. Post-processing such as the removal of burrs, which is a part, is also simplified, and post-processing such as filling time of the low-melting-point alloy material, removal of castings, and deburring can be shortened. And it has a good effect, such as it is possible to mass production can be shortened to.

[Brief description of the drawings]

FIG. 1 is a perspective view of the casting mold according to the present invention with the mold opened, FIG. 2 is a cross-sectional explanatory view of the casting mold cut along the line II in FIG. 1, and FIG. FIG. 2 is a partially enlarged view of FIG.
FIG. 4 is a view of one of the casting molds provided with the plug members as viewed from a division plane. DESCRIPTION OF SYMBOLS 1 ... 1st casting type | mold 1a ... Dividing surface 2 ... 2nd casting type | mold 2a ... Dividing surface 3 ... Casting space 4 ... Hot water supply port 5 ... Runner 6 ... Through-hole 7 ... Plug member 7a Tip surface 8 Body 9 Heating member Cooling member 11 Lead wire 12 Thermocouple

Claims (3)

(57) [Claims] A casting cavity (3) is formed by a first casting mold (1) and a second casting mold (2) which are in contact with and separated from each other, and a runner (3) is formed in the casting cavity (3). 5) Via hot water supply port (4)
A casting mold filled with a low melting point alloy material from at least one of the first casting mold (1) and the second casting mold (2), and a through hole (6) opened in the runner (5).
A plug member (7) containing a heating member (9) and a cooling member (10) is movably disposed in the through hole (6), and the plug member (7) is moved by moving the plug member (7). A casting mold wherein the runner (5) can be closed. 2. The plug member (7) comprises a main body (8) made of a good heat transfer material, a heating member (9) made of a heater embedded in the main body (8), and a cooling member made of a cooling pipe. 10. The casting mold according to claim 1, comprising: 3. The plug member (7) according to claim 1 is heated by a built-in heating member (9), and the hot water is passed through the runner (5) in a state where the runner (5) is held at an open position. A cavity for casting low melting point alloy material from the supply port (4) (3)
After the filling is completed, the cooling of the low melting point alloy material in the casting cavity (3) is started, and the plug member (7) is
A casting method comprising moving the runner (5) to a position where the runner (5) is closed and cooling the runner (5) by a built-in cooling member (10).