JPH0511525B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a mold temperature control device for controlling the temperature of a mold for molding synthetic resin or the like within a predetermined range. If it is possible, the cooling water of the refrigerator can be used directly as a refrigerant for the mold without using the refrigerator.

BACKGROUND ART In order to control the temperature of a mold for molding synthetic resin or the like within a predetermined range, a mold temperature control device is required to cool the mold.

Figure 4 shows the system of a conventional mold temperature control device.
The main flow is that the refrigerant goes from the storage tank 1 to the mold 11 via the piping 3 by the pump 2, and the refrigerant whose temperature has increased by cooling the mold returns to the storage tank 1 through the return piping 22. A part of the refrigerant enters the bypass pipe 26 from 3, is cooled by the evaporator 5 of the refrigerator, passes through the flow control valve 7, and joins the return pipe 22. The refrigerator includes a compressor 23, a condenser 24,
expansion valve 25, cooling water inlet pipe 15, valve 16,
It has an outlet pipe 29 and the like. A portion of the refrigerant flowing from the evaporator 5 into the return pipe 22 flows into the bypass pipe 8 before the flow rate control valve 7, and passes through the flow rate control valve 9.
It is connected to the suction port of the pump 2 through the . The flow rate adjustment valve 9 corrects minute fluctuations in refrigerant temperature that the flow rate adjustment valve 7 could not handle. The valve 14 of the flow path 12 that bypasses the mold is normally closed, and the valves 10 and 13 are open. When the device starts operating, the valve 14 is opened until the set temperature is reached, and the valves 10 and 13 are closed during operation (the tank 1 is usually provided with heating means, although not shown). When the valve 14,1 is activated,
0, 13, etc. are not necessary.

Generally, the refrigerant of the mold temperature control device is used in a wide range of temperatures from low to high temperatures depending on the type of synthetic resin to be molded. In the case of a low-temperature refrigerant that is lower than the cooling water temperature, it is necessary to control the refrigerant temperature using a refrigerator, but if the required refrigerant temperature is higher than the cooling water temperature of the refrigerator, it is uneconomical to operate the refrigerator. Therefore, it is better to use the cooling water as it is as a refrigerant for controlling the mold temperature.

Means for Solving Problems In this invention, in order to solve the conventional drawbacks, the cooling water piping to the condenser is branched, one is connected to the condenser, and the other is connected to the return piping from the mold. If the temperature of the refrigerant used to cool the mold can be high, the operation of the refrigerator is stopped, and the cooling water is not led to the condenser, but directly fed into the refrigerant circuit of the mold and used as a refrigerant.

Embodiment FIG. 1 shows a first embodiment of the present invention, the main parts of which are the same as those of FIG. 4, and the same reference numerals as in FIG. 4 represent the same parts. In this invention, the cooling water inlet pipe 15 is branched, one enters the condenser 24 via the valve 16 as in the conventional case, and the other enters the cooling water bypass pipe 1.
7 and merges with the refrigerant bypass pipe 6 via the valve 18. Further, a refrigerant bypass pipe 26 from the discharge pipe 3 from the pump 2 is provided with a valve 4 upstream of the evaporator. Further, the cooling water discharge pipe 29 and the discharge pipe 3 are connected via the valve 19 by the bypass pipe 20. This valve 19 is controlled by a limit switch 27 that controls the water level of the tank 1, and is for preventing overflow of the tank. Broken lines indicate signal lines.

Figure 1 shows the state of the system when the refrigerator is operating in the same way as Figure 4, with valves 18 and 1 painted in black.
9 is closed. (As mentioned above, the valve 14 is normally closed.) Also, the valves 4 and 16 are kept open.
The refrigerator will then operate normally, with cooling water entering the condenser from the inlet pipe 15 via the valve 16 and exiting through the outlet pipe 29. The operation of the refrigerant for cooling the mold is also as explained in FIG.

Next, if the refrigerant temperature is high and the cooling water is used directly as a refrigerant, as shown in FIG. 2, valves 18 and 19 are opened and valves 4 and 16 are closed.
Refrigerator operation will stop. In this way, the cooling water will not go to the condenser from pipe 15, and cooling water bypass pipe 1
It enters the bypass pipe 6 from 7, goes to the tank 1, enters the mold 11 from the discharge pipe 3 by the pump 2, returns to the tank 1 via the return pipe 22 after cooling the mold. Also, a bypass pipe 20 branched from the discharge pipe 3
The cooling water is then discharged via the valve 19 to the outlet pipe 29. The tank 1 is provided with a level switch 27 that detects the upper and lower limits of the water level in the tank and opens and closes the valve 19 to prevent the tank 1 from overflowing.

If the refrigerant does not need to be at a high temperature as described above, the temperature can be controlled by mixing the cooling water of the condenser into the refrigerant path.

Fig. 3 is basically the same as Fig. 2, but in order to prevent overflow of the tank 1, an outflow pipe 21 and a valve 28 are provided on the side of the upper limit water level ▽W in the tank 1. This is an example, and it is clear that the level switch 27, valve 19, and bypass pipe 20 are omitted compared to FIG. 2.

Effects This invention has such a configuration, and the cooling water of the condenser of the refrigerator can be used as a refrigerant for cooling the mold, so when the refrigerant temperature is high, the cooling water can be used directly and the cooling This is an extremely economical device since there is no need to operate the machine.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the cooling system of the apparatus of the present invention, and shows the case where the refrigerator is in operation;
The figure shows a case in which the refrigerator is actually stopped, Figure 3 shows another embodiment in which an overflow valve is provided in the tank, and Figure 4 shows a conventional cooling system. . Explanation of symbols, 1...Tank, 2...Pump, 3
...Discharge piping, 4...Valve, 5...Evaporator, 6...
Refrigerant bypass, 7... Valve, 8... Refrigerant bypass,
9... Valve, 10... Valve, 11... Mold, 12...
Bypass piping, 13... valve, 14... valve, 15...
... Cooling water inlet pipe, 16 ... Valve, 17 ... Cooling water bypass, 18 ... Valve, 19 ... Valve, 20 ... Cooling water return pipe, 21 ... Outflow pipe, 22 ... Return pipe, 23 ... ...Compressor, 24...Condenser, 25...
Expansion valve, 26... Refrigerant bypass, 27... Limit switch, 28... Valve, 29... Cooling water outlet pipe.

Claims (1)

[Scope of Claims] 1. A pump for pumping refrigerant provided on the upstream side of a mold used for molding synthetic resin, etc., a refrigerant storage tank provided on the suction side of the pump, and cooling piping branched from the discharge side of the pump. The compressor, condenser,
A mold temperature adjustment device that includes a refrigerator configured with an expansion valve, an evaporator, etc., and adjusts the refrigerant temperature by mixing the refrigerant cooled by the refrigerator with the refrigerant heat exchanged in the mold, A mold temperature control device, characterized in that the mold temperature control device is configured such that a refrigerant for cooling a condenser attached to the refrigerator can be mixed into the refrigerant heat exchanged in the mold. 2 Branch the cooling water inlet pipe of the condenser,
2. The mold temperature control device according to claim 1, wherein one end is connected to a condenser inlet, and the other end is connected to a return pipe to a tank and/or a pump suction side. 3. The above-mentioned patent claim, characterized in that a valve is provided immediately before the cooling water inlet for cooling the condenser, immediately before the mold refrigerant inlet of the evaporator, and in a pipe branched from the cooling water inlet pipe of the condenser. 2. The mold temperature control device according to item 2.