JPS626311A - Isothermal temperature controller - Google Patents

Abstract

PURPOSE:To improve the precooling efficiency of a refrigerant by providing a heat accumulating tank at the secondary side of a cooling unit of the refrigerant and connecting the 2nd solenoid valve to the output side of a load supply pump to bypass the load. CONSTITUTION:The refrigerant circuit of a working machine 9 is provided with a cooling unit 1 containing a compressor 2, a condenser 3, a decompressor 4 and an evaporator 5, a heat accumulating tank 6, a pipeline 7 and a pump 8. Then, the refrigerant circuit uses water as the refrigerant and cools a heat generating part 10 of the machine 9 through the 1st solenoid valve 11. Here, the 2nd solenoid valve 13 is set between the output side of the pump 8 and the exit side of a check valve 12. Thus, a bypass circuit of the machine 9 is formed. Then, a compressor 2 is driven with application of an operation switch and at the same time both solenoid valves 11 and 13 are opened. While the water of the tank 6 is circulated by the pump 8 through the bypass circuit and the machine 9. Then, the valve 13 is closed to cool the part 10 when the operation of the machine 9 is ready.

Description

[Detailed description of the invention] (a) Industrial application field The present invention is used for constant temperature control of processing machines such as electrolytic machine tools, high frequency heating devices, and resin molding machines that require circulating brine to maintain a constant temperature. In particular, it concerns the precooling of this brine.

(b) Conventional technology In general, as a conventional constant temperature control device, Japanese Patent Application Laid-Open No. 57-342
There was something like the one described in Publication No. 12. This publication describes a method in which a constant temperature bath is provided, the brine in the constant temperature bath is circulated between a water chiller, the brine is cooled, and the brine is further circulated between the constant temperature bath and the load to cool the load. Met. By keeping the temperature of the brine in this constant temperature oven constant, the temperature of the load was also kept constant.

(c) Problems to be Solved by the Invention In the conventional technology configured as described above, the first pump circulates brine between the heat storage tank and the water chiller, and the brine is circulated between the heat storage tank and the load. Is it necessary to have a second pump for circulation?

Further, since the first and second pumps form circuits through which brine flows, the circuits through which brine flows may be short-circuited within the heat storage tank.

In view of these problems, the present invention provides a constant temperature control device that uses a single pump and does not cause short circuits in the circuit through which brine flows.

(2) Means for Solving Problems The constant temperature control device of the present invention includes a cooling unit that cools a circulating refrigerant, a heat storage tank connected to the secondary side of this cooling unit, and a first A pump that supplies the load via a solenoid valve and a second solenoid valve that is installed on the discharge side of this pump and bypasses the load are connected in a ring with piping, and the brine in the heat storage tank is pre-cooled at the start of operation. It is equipped with a section.

(E) Function The constant temperature control device configured as described above can pre-cool the heat storage tank during the load preparation time. Therefore, cooling operation can be performed in accordance with the start-up of the load.

(F) Embodiments Below, embodiments of the present invention will be described based on the drawings. FIG. 1 is a refrigerant circuit diagram when a processing machine is used as the load, and water is used as the brine.

In the figure, (1) is a cooling unit, for example a compressor (2).
, a condenser (3), a pressure reducing device (4), and an evaporator (5) constitute a refrigeration cycle, and the evaporator (5) cools water. (6) is a heat storage tank, and the piping (7
) is connected to the cooling unit +11. (8) is a pump that circulates water, and supplies water stored in the heat storage tank (6) to the processing machine (9). This processing machine (9) is equipped with a heat generating part QOI, and in order to cool this heat generating part (1G), water flows through the first electromagnetic valve αD. (121 is a check valve, and the processing machine ( C3 is a second electromagnetic valve, which is installed between the discharge side of the pump (8) and the outlet side of the check valve α2, and prevents water from flowing back into the processing machine (9). This constitutes a bypass circuit for the water cooling unit (a) (return piping to II).

Figure 2 is an electric circuit diagram (control section) used in the water circuit shown in Figure 1. Identical components are given the same reference numerals, but in reality they operate via electromagnetic relays. In the figure, α, αe, and αD are the operation switch for the pump (8), the cooling unit) (IJ operation switch, and the operation switch for the processing machine (9), respectively).

The operating switch α9 is connected in series between the power supply buses (1,) and (12) via a pump (8), and a normally open contact piece u8 is provided in parallel with the operating switch α9. C9: Water temperature or outside air temperature is below the specified level (approximately 4 degrees)
This is an antifreeze thermostat that closes the contacts when It is connected to the. The operation switch (161 is a cold water thermostat that opens the contact piece when the water temperature is above a predetermined level) C211, the normally open contact piece that closes when the pump (8) is operating, and the power supply bus (2) in series through the compressor (2). 1,), (star,) are connected between. Solenoid valve 0 is connected in series between power supply buses (1,) and (l,) via normally closed contacts θ, (c). Operation switch (lη is the normally closed terminal of the switching contact (goods) and solenoid valve α
It is connected in series between the power supply buses (l,) and (l,) via υ. The normally open contact of this switching piece is directly connected to the power supply bus (11). ■ is the controller of the processing machine (9), which includes the operation switch η and the power bus (l).
, ). The wire is an electromagnetic relay,
It is installed between the operation switch (171) and the power supply bus [12] in series via a normally open contact piece.The opening and closing of this normally open contact piece @ is controlled by the controller ω, and the processing machine (9) The contact plate is closed when the motor is ready to be driven.

When operating the constant temperature control device configured as described above, the operation switches α9, (161, and (171) may be turned on in sequence. When the operation switch a9 is turned on first, the pump (8) starts driving. At the same time, close the normally open contact ■.Next, turn on the operation switch αQ, and turn on the cold water thermostat (2).
If the contact piece 1 is closed, the compressor (2) is driven. This causes the cooling unit (1) to start cooling the water. Next, when the operation switch C17) is turned on, the control unit ω and the solenoid valve (ID) are energized.This opens the solenoid valve αD.At this time, the normally closed contactor ■ is closed, so the solenoid valve Q31 is turned on. It is energized and becomes open.Therefore, the heat storage tank (
The water stored in 6) is circulated by the pump (8) through the bypass circuit and the processing machine (9). At this time, the water mainly flows into the bypass circuit with lower resistance than the processing machine (9) with higher resistance. By circulating the water in this way, the water cooled in the cooling unit (11) is stored in the heat storage tank (6).

After that, when the processing machine (9) is ready for operation, the normally open contact piece θ
closes and the relay fins are energized. By energizing this relay □□□, the normally closed contact (b) becomes open, and the solenoid valve αJ
energization is stopped. That is, the electromagnetic valve αJ is closed, and the water discharged from the pump (8) flows only to the processing machine (9) to cool the heat generating part aα.

In this way, while the processing machine (9) is preparing to start up, the heat storage tank (6) can be pre-cooled.

In addition, if the water temperature or outside air temperature falls below a predetermined value while the operation switches (151, (161, 0n) are open, that is, the device is in a stopped state, the antifreeze thermostat σ
Contact piece 9 closes and relay ■ is energized. As a result, the normally open contact piece Q81 closes, the pump (8) is driven, and the normally closed contact piece (Q81) is driven.
c) opens and solenoid valve a3 is energized and closed.

Furthermore, the switching switch is switched and the solenoid valve aυ is energized and becomes open. This allows the water discharged from the pump (8) to circulate through the processing machine (9), thereby preventing this water from freezing.

Although water was used as the brine in the above embodiments, the brine is not limited to this. Further, although the control circuit is constructed using a relay and a relay contact piece, it is not limited to this, and may be constructed using a microprocessor.

(g) Effects of the Invention The constant temperature control device of the present invention includes a cooling unit that cools circulating brine, a heat storage tank connected to the secondary side of this cooling unit, and a heat storage tank that controls the brine in the heat storage tank through a first electromagnetic valve. A pump that supplies the load to the load and a second electromagnetic valve that is provided on the discharge side of the pump and bypasses the load are connected in a ring through piping, and the control unit cools the brine in the thermal storage tank in advance at the start of operation. Therefore, the brine circulation circuit can be integrated into one, and in this brine flowing circuit, it is possible to prevent short circuits in the flow through the constant temperature bath as in the conventional case. Furthermore, the brine can be precooled efficiently using a bypass circuit.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an apparatus showing an embodiment of the present invention. FIG. 2 is a control circuit diagram used in FIG. 1. (1; ... cooling unit, (6) ... heat storage tank,
(8)...Pump, (9)...Processing machine, αD
...first solenoid valve, αJ...wII2 solenoid valve.

Claims (1)

[Claims] (1) A cooling unit that cools circulating brine, a heat storage tank connected to the secondary side of this cooling unit, a pump that supplies the brine in this heat storage tank to a load via a first electromagnetic valve, and this pump a second solenoid valve provided on the discharge side of the storage tank for bypassing the load, and a control unit that is connected in an annular manner with piping to cool the brine in the thermal storage tank in advance when the load starts operating. Device.