JPH04221615A - Cast molding device for resin - Google Patents

Abstract

PURPOSE:To manufacture an epoxy cast material where productivity is improved and a quality is stabilized, by a method wherein the title device is a device of vacuum-casting an epoxy casting material which uses high voltage and the epoxy casting resin is cast into a casting mold without necessitating a skill by performing defoaming swiftly. CONSTITUTION:An exhaust port 20 of a mold and exhaust port opening and closing mechanism 19 opening and closing the exhaust port 20 are provided in casting molds 12a, 12b which are held within a casting tank 13 and piping 14 casting epoxy casting resin from a resin tank 9 is connected with the casting molds 12a, 12b. In the case where exhaust is performed, the casting molds 12a, 12b and casting tank 13 are exhausted at the same time by opening the exhaust port 20 of the mold, the predefoamed epoxy casting resin is cast into the casting molds 12a, 12b and in the case where the cast epoxy casting resin is pressurized, the exhaust port 20 of the mold is closed and pressurized air is supplied through the piping 14.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin casting apparatus for producing cast products such as resin molded coils used at high voltages and large currents, such as propulsion coils for superconducting magnetic levitation railways.

0003

2. Description of the Related Art Electrical equipment used at high voltages and large currents, such as propulsion coils for superconducting magnetic levitation trains and main components of gas circuit breakers, are usually manufactured by epoxy resin casting. Epoxy resin cast products (hereinafter referred to as cast products) generally have excellent electrical and mechanical properties. It is important to prevent partial discharges from occurring during the test. If minute voids exist in the epoxy resin part of the cast product, the electric field will concentrate on the void parts, making it easy to cause partial discharge. For this reason, vacuum casting is used to cast epoxy resin into electrical equipment used at high voltages, such as propulsion coils for superconducting magnetic levitation trains and the main components of gas circuit breakers. This vacuum casting method is performed using, for example, an apparatus as shown in FIG. That is, the casting hardware 2a, 2b holding the cast object 1, such as a coil wound with a conducting wire, in a predetermined position is stored in the casting tank 3, and the resin outlet 4 and the casting hardware 2a, 2b are placed in a casting tank 3. A gutter 5 is placed between the openings provided at the top of the . In this state, vacuum valve 6
The inside of the casting tank 3 is evacuated by the vacuum pump 7. After the inside of the casting tank 3 has reached a sufficient degree of vacuum, the resin valve 8 is opened and the epoxy casting mold (not shown) housed inside the resin tank 9 is opened. A resin (hereinafter referred to as resin) is injected into the casting molds 1a and 1b through the gutter 5. After that, the leak valve 10 is opened to once release the inside of the casting tank 3 to atmospheric pressure, and then the leak valve 10 is closed and the pressurizing valve 11 is opened to supply pressurized air to pressurize the inside of the casting tank 3. . Air bubbles remaining in the resin in the resin tank 9 are removed by foaming in a vacuum when flowing through the gutter 5, and are removed from the casting molds 2a,
By pressurizing the inside of 2b, it is possible to crush vacuum voids remaining inside the cast product and obtain a cast product in which no voids are formed and partial discharge is less likely to occur. however,
In this method, the resin is degassed while flowing over the gutter 5, so the resin needs to be poured over the gutter 5 little by little, which requires skill and time, and ensures stable quality of the cast product. is difficult to obtain or is not suitable for mass production. Also, casting tank 3
However, the structure needed to withstand both vacuum and pressure, making the structure complicated and expensive.

0004

[Problems to be Solved by the Invention] As mentioned above, vacuum casting is used to cast products that are used at high voltage, but conventional vacuum casting requires skill and time. However, there are disadvantages in that it is difficult to obtain products of stable quality and it is not suitable for mass production, and it also requires expensive equipment.

[0005] The purpose of the present invention is to make it possible to obtain products of stable quality in a short time without requiring any skill in the vacuum casting of cast products used at high voltage, and to enable mass production. An object of the present invention is to provide a resin casting device that can be an inexpensive device. [Structure of the invention]

[0006]

[Means for Solving the Problems] The present invention as set forth in claim 1 provides a casting mold, a casting tank that accommodates the casting mold and is capable of evacuating the casting mold, and a casting tank disposed above the casting tank. The casting mold is equipped with a resin tank that stores resin, and the casting mold is connected to an openable and closable exhaust port and a resin flow path that communicates with the resin tank. It is constructed so that fluid can flow therethrough.

[0007]

[Operation] Open the exhaust port of the casting mold that houses and holds the object to be poured, and exhaust the casting mold at the same time as the casting tank. Thereafter, the resin that has been degassed in advance from the resin tank is injected into the casting mold via the resin flow path. After this, the exhaust port of the casting mold is closed, and pressurized fluid is supplied to the casting mold through the resin channel to pressurize the injected resin and crush vacuum voids.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing one embodiment of the present invention. In the figure, 1 is an object to be cast, 12a and 12b are casting molds that hold the object 1 in a predetermined position, 3 is a housing for housing the casting dies 12a and 12b, and a vacuum valve 6, This is a casting tank in which a leak valve 10 is provided and a pipe 14 is introduced from the outside to connect one end to casting molds 12a and 12b and inject resin. Further, a sealable lid 15 is attached to the resin tank 9 to which the other end of the piping 14 is connected.
This lid 15 is provided with a vacuum valve 16 and a leak valve 17, and the vacuum valve 16 is connected to the casting tank 1 through a pipe 18.
Connect to the vacuum valve 6 of 3. On the other hand, the casting mold 12a,
An exhaust port opening/closing mechanism 19 is provided at the upper part of 12b. This exhaust port opening/closing mechanism 19 is for opening and closing a mold exhaust port 20 provided in the casting mold 12a, and has a solenoid valve (or air cylinder) 21 attached to the casting mold 12a as a main component. , a solenoid valve (or air cylinder) is installed in the casting mold 12a.
A valve seat 12c is formed on which the valve body 21a provided in the movable part of the casting mold 12b moves. (or valve). Next, the operation of the resin casting apparatus configured as above will be explained. first,
Casting mold 12a, 1 holding object 1 to be cast in a predetermined position
2b is set in the casting tank 13, and the piping 14 is connected to the casting mold 12b. Further, the mold exhaust port 20 of the casting mold 12a is left open. In this state, the vacuum valve 6 is opened and the inside of the casting tank 13 is evacuated to a predetermined degree of vacuum. At about the same time, the vacuum valve 16 containing the resin (not shown) is opened to evacuate the inside of the resin tank 9 and degas the resin. When the resin has been defoamed, close the vacuum valve 16 and open the leak valve 17.
, and return the inside of the resin tank 9 to atmospheric pressure. Next, by opening the resin valve 8, the resin is poured into the casting mold 12a.
, 12b due to the potential energy and the pressure difference between the vacuum and the atmosphere. The mold exhaust port 20 is closed by the exhaust port opening/closing mechanism 19 when a certain amount of resin has flowed. Even after the mold exhaust port 20 is closed, the insides of the casting molds 12a, 12b, which do not contain resin, are kept in a vacuum, so that the insides of the casting molds 12a, 12b are filled with resin. Thereafter, the resin valve 8 is closed and the pressure valve 11 is opened to pressurize the insides of the casting molds 12a and 12b, thereby crushing vacuum voids remaining inside the casting.

As described above, according to this embodiment, the resin is poured into the casting molds 12a and 12b at high speed, and the quality is stabilized using an inexpensive device in which the pressure of pressurized air does not act on the casting tank 13. It is possible to easily produce cast products in large quantities.

0010

Effects of the Invention As explained above, according to the present invention, a casting mold housed in a casting tank is provided with an exhaust port communicating with the casting tank and a mechanism for opening and closing this exhaust port. and the casting mold at the same time, and the previously defoamed resin was injected into the casting mold from a position higher than the casting mold, and then pressurized air was supplied and injected through the resin flow path. Since the resin is pressurized, it is possible to easily produce a large quantity of cast products with improved productivity and stable quality, and it is possible to provide a resin casting apparatus that is inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention.

FIG. 2 is a sectional view showing the configuration of a conventional resin casting device.

[Explanation of symbols]

1... Casting object, 7... Vacuum pump, 9... Resin tank, 12
a, 12b...Casting mold, 13...Casting tank, 14...Piping, 19...Exhaust port opening/closing mechanism, 20...Exhaust port.

Claims (1)

[Claims] 1. A casting mold, a casting tank that accommodates the casting mold and is capable of being evacuated, and a resin tank disposed above the casting tank and containing an epoxy casting resin; The casting mold is connected to an openable and closable exhaust port and a resin flow path communicating with the resin tank, and the pressurized fluid of the epoxy casting resin injected into the casting mold can flow through the resin flow path. A resin casting device characterized in that it is configured as follows.