JPS5931397Y2 - transfer molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer molding machine, and more particularly to a device for shortening the curing time of the cull portion of a molded product.

The prior art will be explained using FIGS. 1 and 2.

First, resin 1 is poured into pot 2 as shown in FIG.

Then, the descending plunger 3 fills the runner 6 and cavity 7 formed by the upper mold 4 and lower mold 5 with the resin 1, resulting in a state as shown in FIG.

Among them, a plunger drive section (not shown) is installed on the upper frame 8.

The upper mold 4 and the lower mold 5 are heated to the resin 1 by a built-in heater 25, thermocouple 26, and external temperature controller (not shown).
The temperature at which it hardens (150 to 200°C as mold temperature)
is held in

Therefore, the resin in the cavity 7 and runner 6 is cured after a certain period of time.

However, since the plunger 3 does not have a heat source, in the elevated state as shown in FIG. 1, the room temperature is 100° C. or more lower than the mold temperature, so it is cooled by the outside air.

In order to pour in the resin 1 and clean the molds 4 and 5, it is usually necessary to take out the plunger 3 into the pot 2 for 1 to 2 minutes as shown in Figure 1, and the temperature of the bottom surface 9 of the plunger is approximately the same as the mold temperature. The temperature has dropped by more than 20℃.

Therefore, when curing the resin in the state shown in Figure 2, the molded product cull 10 is in contact with the low-temperature plunger bottom 9, so curing is poor, and a long curing time is required to fully cure the cull portion 10, resulting in molding. The drawback was that it was less efficient.

Furthermore, since the resin in the cull part is insufficiently cured, there is a drawback that the mold in this part is heavily contaminated by unreacted substances.

In order to solve the above-mentioned problems, the present invention incorporates an electric heater and a heat sensitive element inside the plunger, and provides a temperature regulator connected to the electric heater button and heat sensitive body. The purpose of the present invention is to provide a transfer molding machine that can shorten the molding time (the time from when the plunger is lowered to when the mold opens to take out the product).

The present invention will be explained below with reference to an embodiment shown in FIGS. 3 and 4.

The buttons in each figure with the same numbers as in Figure 1 are the same parts.

As shown in FIG.
2 and a plunger lower part 13, with a heat insulating material 1 in the middle.
9 (for example, asbestos) is inserted, and both parts 12 and 13 are screwed together for strength.

In this way, both 12 and 13 are connected by screw fastening, and the heat conduction area is reduced by the heat insulating material 19. Therefore, the heat from the plunger lower part 13 is connected to the plunger driving device (not shown). This is to minimize conduction to the plunger upper part 12.

As shown in FIG. 4, the lower part 13 of the plunger has a hole 20.2.
A cartridge heater 14 for heating the bottom of the plunger is buried in the hole 20, and a heat sensitive element 15 (for detecting the temperature of the bottom of the plunger) is embedded in the hole 21.
For example, thermocouples and thermistors) are embedded in each.

Conductive wires 22 and 23I/'i connected to the cartridge heater 14 and the heat sensitive body 15 pass through holes 16 and 17 drilled in the sides of the plunger lower part 13, respectively, and are connected to a temperature regulator 18 installed outside. There is.

A plunger bottom plate 24 is attached to the bottom surface of the plunger lower part 13.

Since the configuration is as described above, the heat sensitive body 15 and the temperature regulator 18
By adjusting the power applied to the cartridge heater 14, the temperature of the plunger bottom 2 can be maintained at a desired resin curing temperature.

As shown in FIG. 3, if the thermosetting resin is molded with the plunger bottom 24 at the same temperature as the mold temperature, the resin in the cull part 10 will be absorbed into the product cavity 7 and even if the molding time is shorter than before. The resin of the runner part 6 will not be insufficiently cured.

For example, when molding is performed using an acid anhydride-curing epoxy molding material, the mold temperature is 1.
It took a molding time of 3 ml at 70° C., but with the transfer molding machine according to the present invention, the mold temperature and plunger bottom temperature were both set at 170° C., and the cull portion 10 could be solidly molded in about 1.5 ml.

As explained in detail above, according to the present invention, an electric heater button and a heat sensitive body are built into the plunger, and a temperature regulator is provided connected to the electric heater button and heat sensitive body, so that transfer molding is possible. Curing of the cull part caused by molding becomes faster and molding time can be shortened.

Furthermore, according to the present invention, since the cull portion is sufficiently cured, it is possible to prevent uncured materials from adhering to the bottom of the plunger, and to reduce the possibility that they will fall and contaminate the mold, etc. The plunger and the mold can be easily cleaned, and the number of times the mold must be cleaned can be reduced.

Therefore, the efficiency of transfer molding can be improved by these.

Furthermore, with the transfer molding machine according to the present invention, it is possible to keep the temperature of the bottom of the plunger and the mold surface, which are in direct contact with the resin during curing, at the same temperature, so the temperature is around room temperature and 150 - 150℃.
Even with resins whose curing properties differ significantly depending on the temperature at 200°C, such as epoxy molding materials containing latent curing accelerators, the cull portion can be cured quickly and cured in the same molding cycle.

Furthermore, according to the present invention, since the temperature of the plunger is maintained constant, it is possible to prevent a fitting gap between the plunger and the mold, thereby preventing the occurrence of nozzles between the plunger and the mold. This has the practical effect of preventing wear of the plunger and providing a highly reliable transfer molding machine.

[Brief explanation of the drawing]

Figures 1 and 2 are diagrams showing parts related to resin curing of a conventional transfer molding machine, with Figure 1 showing the state in which the plunger is raised, and Figure 2 showing the state in which the plunger is lowered. 3 is a block diagram showing an embodiment of the transfer molding machine according to the present invention, and FIG. 4 is a sectional view showing details of the lower part of the plunger shown in FIG. 3. Explanation of symbols: 11... Plunger, 14... Cartridge, heater, 15... Heat sensitive element, 18... Temperature regulator.

Claims (1)

[Scope of utility model registration request] An electric heater button and a heat sensitive body are built into the lower part of the plunger inserted into the pot in the transfer molding machine, and the temperature at the bottom of the plunger is connected to the electric heater and the heat sensitive body and sensed by the heat sensitive body. According to the present invention, a temperature controller is provided to adjust the temperature at which the bottom of the plunger is heated by the electric heater, and the lower part of the plunger is integrally connected to the upper part of the plunger connected to the plunger driving device via a heat insulating material. Transfer molding machine.