JPH07304041A - Heating or cooling device for mold - Google Patents

Abstract

PURPOSE:To shorten a molding cycle, eliminate occurrence of variation in temperature, and provide a breathing hole in an arbitrary position. CONSTITUTION:Heat exchanging chambers 6, 7 are formed in molds 1, 2. The heat exchanging chambers 6, 7 are connected to a molding part 13 with a plurality of pores. A heating fluid supply tube 3 and a cooling fluid supply tube 4 are connected to the heat exchanging chambers 6, 7 through headers 8, 9. A suction means 5 is connected to the lower parts of the heat exchanging chambers 6, 7 through a pipe 19 and a steam trap 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold device for heating and cooling. Usually, when molding a thermoplastic synthetic resin in a mold, heating or cooling the mold is performed as needed during a cycle from injection of raw materials into the mold to molding and release. .

[0002]

2. Description of the Related Art As a conventional mold heating / cooling device, a device as shown in FIG. 2 has been used. In FIG. 2, the central portion of the left and right dies 50 and 51 is used as a molding portion 61, and
A large number of pipe-shaped passages 52, 53 are continuously provided inside, and by connecting the separately arranged high temperature oil tank 54 and low temperature oil tank 55 through circulation pumps 56, 57, high temperature oil tank 54 is used for heating. The molds 50 and 51 are heated by supplying high temperature oil from the oil tank 54 to the pipe-shaped passages 52 and 53, and at the same time, the low temperature oil is supplied from the low temperature oil tank 55 to the pipe-shaped passages 52 and 53. By doing so, the molds 50 and 51 are cooled. In addition, a plurality of communication passages 58, 5 communicating the molding portion 61 and the outside inside the mold.
9, 60 are provided to exclude the gas generated during molding to the outside.

[0003]

In the conventional mold heating / cooling apparatus described above, since oil is used as the heating / cooling medium, it takes a long time for the mold to reach the desired temperature. There is a problem that the cycle becomes long and the production efficiency becomes low. Usually, the mold is thick in order to hold a high-pressure raw material, and its heat capacity is large, so it takes time to reach a desired temperature.

Further, in the above-mentioned conventional mold heating / cooling device,
There is a problem in that the temperature distribution on the mold surface on the molding part side varies and the quality of the molded product deteriorates. This is because the sensible heat of the oil is used only because the oil is used as a heating / cooling medium, and the heating and cooling heat amounts are not sufficient.

Further, in the above-mentioned conventional mold heating / cooling apparatus,
The pipe-shaped passage 5 is formed by connecting the communication passages 58, 59, 60 for gas removal.
Since it has to be provided away from 2, 53, there is a problem that the installation positions of the communication passages 58, 59, 60 are limited and the processing thereof becomes difficult and the die cost becomes high.

Therefore, the technical problem of the present invention is that the gas exclusion hole can be installed easily and can be provided at an arbitrary position.
The object is to obtain a mold heating or cooling device that can secure a sufficient amount of heat and that the temperature of the mold surface does not fluctuate, and that shortens the molding cycle and improves production efficiency.

[0007]

The structure of the mold heating or cooling device of the present invention is as follows. A mold having a heat exchange chamber for heating or cooling and a molding part, a fluid pipeline for supplying a heating fluid and a cooling fluid to the heat exchange chamber, and a passage for the fluid provided in the fluid pipeline. A valve means for controlling, wherein a suction means for sucking the fluid in the chamber is connected to the heat exchange chamber, and the molding portion and the heat exchange chamber are communicated with each other through a plurality of pores.

[0008]

The mold can be steam-heated by supplying a heating fluid such as steam from the heating fluid conduit to the heat exchange chamber. Since steam has latent heat and sensible heat and has a large heat capacity, the die can be heated quickly and sufficiently.

Since the heat exchange chamber is connected to the suction means, the condensed water of the steam generated by heating is condensed by the suction means and discharged to the outside of the system. When the suction force of the suction means is further increased, the heat exchange chamber can be changed from a pressure state of about atmospheric pressure to a so-called vacuum pressure state of less than atmospheric pressure. When using steam obtained by evaporating ordinary water as steam, the mold can be heated at a steam temperature of 100 ° C. by setting the pressure in the heat exchange chamber to atmospheric pressure, and by setting the pressure to atmospheric pressure or higher. It can be heated at a temperature of 100 ° C. or higher. Further, the mold can be heated at a vapor temperature of 100 ° C. or lower by setting the vacuum pressure state to be atmospheric pressure or lower.

On the other hand, a cooling fluid such as cooling water is supplied from the cooling fluid conduit to the heat exchange chamber, and the suction chamber is used to reduce the pressure of the heat exchange chamber to a pressure equal to or lower than the saturation pressure. The mold can be vaporized and cooled by removing heat and vaporizing. Compared with cooling only by sensible heat of oil, vaporization cooling by water is accompanied by latent heat of vaporization, so that the heat capacity becomes large and the mold can be cooled quickly and sufficiently.

By connecting the molding section and the heat exchange chamber with a plurality of pores and connecting the heat exchange chamber to the suction means, the gas generated in the molding section is sucked by the suction means through the pores and eliminated. To be done. Since the pipe-like passage through which oil passes is no longer required as in the conventional device, the plurality of pores can be provided at any position of the molding part.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrated embodiment will be described in detail. A pair of left and right molds 1, 2, a heating fluid conduit 3 and a cooling fluid conduit 4,
Also, the suction means 5 constitutes a heating or cooling device for the mold.

The molds 1 and 2 have hollow portions 6 and 7 formed therein, and these hollow portions 6 and 7 are used as heat exchange chambers. A molding part 13 is provided at the center of the molds 1 and 2, and a molding raw material (not shown) is injected into the molding part 13. A plurality of pores 30 are provided so as to penetrate between the molding part 13 and the heat exchange chambers 6, 7. Pore 3
As for the diameter of 0, the heat exchange chambers 6 and 7 are connected to the suction means 5 as described later.
Since it is sucked in, a small one may be used, and for example, it can be about 0.05 mm to 0.1 mm. The heating / cooling chambers 6 and 7 are connected to the heating fluid conduit 3 and the cooling fluid conduit 4 via headers 8 and 9. The fluid supplied from the fluid conduits 3 and 4 is supplied from the headers 8 and 9 to the heating / cooling chambers 6 and 7. A pressure control valve 10 for controlling the supply steam pressure and an opening / closing valve 11 are attached to the heating fluid pipeline 3, and an opening / closing valve 12 is also attached to the cooling fluid pipeline 4.

The suction means 5 is connected to the lower portions of the headers 8 and 9. The suction means 5 is composed of an ejector 14, a tank 15 and a circulation pump 16. The ejector 14 is composed of a suction unit 17 having a nozzle built therein and a diffuser 18. The suction portion 17 and the headers 8 and 9 are connected by the conduit 19 and the steam trap 23. The diffuser 18 is connected to the tank 15, the lower portion of the tank 15 is connected to the suction port of the circulation pump 16, and the discharge port is connected to the suction portion 17 of the ejector 14. The ejector 14 circulates the fluid in the tank 15 by the circulation pump 16 and passes the fluid to the suction unit 17, thereby generating a suction force at the built-in nozzle unit. Although not shown, the tank 15 has a liquid level sensor for detecting an internal liquid level and a temperature sensor 21 for detecting a liquid temperature.
The cooling fluid supply pipe 20 branched from the cooling fluid pipe 4 is connected to the upper portion of the tank 15 via the control valve 22, and the temperature sensor 21 and the control valve 22 connect the tank 15
Maintain the fluid temperature within the desired value.

Next, the operation will be described. When heating the molds 1 and 2, the set pressure value of the pressure control valve 10 is set to a predetermined value and the opening / closing valve 11 is opened, and heating steam is supplied from the heating fluid conduit 3 to the headers 8, 9 Is supplied to the heat exchange chambers 6 and 7. The molds 1 and 2 are heated by the steam having a predetermined pressure, and the steam is condensed to be condensed water. Condensate is sucked by the suction unit 17 of the suction unit 5.
Is sucked in through the conduit 19 and the steam trap 23,
When it reaches the tank 15 and the liquid level in the tank 15 becomes high, it is discharged outside the system at any time.

The heating temperature can be appropriately set by adjusting the set pressure of the pressure control valve 10 and the temperature of the liquid passing the suction force of the suction section 17. For example, the heating temperature is 100
If a relatively high temperature of C or higher is desired, the pressure control valve 10
This can be achieved by setting the set pressure of above to a pressure equal to or higher than the atmospheric pressure and making the suction force of the suction means 5 slightly lower than that pressure. When the molds 1 and 2 are heated at a relatively low temperature of 100 ° C. or lower, the set pressure of the pressure control valve 10 is set to a vacuum pressure of atmospheric pressure or lower, and the suction force of the suction means 5 is applied to the tank 15 as a cooling fluid. This can be done by replenishing the cooling fluid from the replenishment pipe 20 to raise the temperature of the fluid by lowering it, and slightly lowering it than the set pressure of the pressure control valve 10.

When cooling, instead of supplying steam, cooling water is supplied from the cooling fluid pipe 4 to the heat exchange chambers 6 and 7, and the suction means 5 is driven to move the inside of the heat exchange chambers 6 and 7. When the pressure is reduced, the supplied cooling water absorbs heat from the molds 1 and 2 and is vaporized to be cooled. The vaporized vapor and a part of the cooling water that remains without being vaporized are sucked by the suction portion 17 of the suction means 5 and discharged to the outside of the system. As for the cooling temperature, the temperature of the fluid passing through the suction force of the suction unit 17 is measured by a temperature sensor.
It can be adjusted and appropriately set by detecting by 21 and controlling the opening / closing of the control valve 22.

The gas generated in the molding part 13 can be appropriately removed by sucking it with the suction means 5 from the pores 30 installed at an arbitrary position.

In this embodiment, an example in which the ejector 14, the tank 15 and the circulation pump 16 are combined as the suction means 5 is shown, but a conventionally known water-sealed vacuum pump or the like can also be used.

[0020]

According to the present invention, the mold can be heated or cooled by the large latent heats of the vapor and the vaporized cooling fluid, and the mold can be heated and cooled quickly and sufficiently to complete the molding cycle. It can be shortened, the quality of the molded product can be prevented from deteriorating without causing the mold surface temperature to fluctuate, and the gas exclusion hole can be easily installed at an arbitrary position.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a mold heating or cooling device of the present invention.

FIG. 2 is a configuration diagram showing a conventional mold heating / cooling device.

[Explanation of symbols]

 1, 2 Mold 3 Heating fluid pipeline 4 Cooling fluid pipeline 5 Suction means 6, 7 Heat exchange chamber 10 Pressure control valve 14 Ejector 15 Tank 16 Circulation pump 17 Suction part 30 Pore

Claims (1)

[Claims] 1. A mold having a heat exchange chamber for heating or cooling and a molding section, a fluid pipeline for supplying a heating fluid and a cooling fluid to the heat exchange chamber, and a fluid pipeline provided in the fluid pipeline. A valve means for controlling passage of the fluid, a suction means for sucking the fluid in the chamber is connected to the heat exchange chamber, and the molding portion and the heat exchange chamber are communicated with each other through a plurality of pores. A mold heating or cooling device.