JP3218438B2 - Mold cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a molding die, and more particularly to a cooling water chiller unit having a compressor, a condenser and an evaporator for cooling water by the evaporator, and an inlet and an outlet. A supply pipe and a return pipe for connecting the mold with the chilled water chiller unit to the cold water chiller unit, supplying cold water from the chilled water chiller unit to the inflow section through the supply pipe, and cooling the mold from the outflow section. The present invention relates to a cooling device for a molding die that circulates water after returning to the cold water chiller unit.

[0002]

2. Description of the Related Art Conventional cooling devices for molding dies include, for example,
As shown in FIG. 4, a cooling tank D in which an evaporator C composed of a cooling pipe connected to a condensing unit A having a compressor via a refrigerant pipe B is provided, and a pump E is provided. A supply pipe G for supplying cold water from the cooling tank D to the mold F, and the mold F
And a return pipe H for returning the water after cooling to the cooling tank D, and supplying the cold water cooled in the cooling tank D by the operation of the pump E to the mold F and through the return pipe H. And circulating the water after cooling the mold F back to the cooling tank D, or as shown in FIG.
A chilled water chiller unit J having a compressor, a condenser and an evaporator is used, a chilled water tank K for storing chilled water cooled by the unit J and a pump E are provided, and the chilled water in the chilled water tank K is molded by a mold. F, and a return pipe H for returning the water after cooling the mold F to the cooling tank K. The pump E operates to supply the cold water accumulated in the cold water tank K to the mold K. F
And circulating the water after cooling the mold F through the return pipe H so as to return to the cold water tank K. In each case, the cooling capacity of the compressor is set so as to correspond to the maximum load in the mold F, and the temperature of the chilled water supplied to the mold F by starting and stopping the compressor is set to a set temperature. For example, 10
It is about 15 ° C. 4 and 5, L denotes a bypass pipe having a bypass valve M, and P denotes a cold water circulation path N.
It is a circulation pump interposed in

[0003]

However, in these conventional cooling devices for molding dies, when the load on the dies F decreases and the temperature of the water after cooling the dies F decreases, the dies are cooled. Since the temperature of the cold water supplied to the mold F also decreases, the compressor is stopped, the temperature of the cold water supplied to the mold F is increased, and the temperature of the cold water supplied to the mold F is set to the set temperature. When the load on the mold F is small, the compressor frequently stops and starts and stops frequently. When the start and stop frequency increases, the starting current only flows frequently. And adversely affect the mechanical life. That is, to explain the latter configuration, for example, when a compressor having a cooling capacity of 30,000 kcal / h is used, the capacity of the cold water tank K is 100 liters, and the temperature range of the cold water is 2 ° C. If the load at F is 50%, the operation time and the stop time of the compressor are 48 seconds, and the start and stop are repeated every 48 seconds.
If it is set to ° C., start and stop will be repeated every shorter 24 seconds. For this reason, in the related art, the temperature of the water after cooling the mold F by increasing the capacity of the cooling tank D or the cold water tank K does not easily affect the temperature of the cold water supplied to the mold F. This prevents the compressor from starting and stopping frequently. In such a case, since the capacity of the cooling tank D and the cooling water tank K needs to be increased, there has been a problem that the entire mold cooling apparatus cannot be reduced in size.

As another measure for avoiding frequent starting and stopping of the compressor, for example, an electric heater whose capacity can be controlled is provided in the water suction pipe portion of the pump E in FIG. 4 and the cold water tank K in FIG. In order to reduce the capacity of the cooling tank D or the cold water tank K while reducing the capacity of the cooling tank D or the cold water tank K so that the sum of the calorific value of the electric heater and the load of the mold F is balanced with the cooling capacity of the compressor. It is conceivable to prevent frequent starting and stopping. However, in this case, it is necessary to use an electric heater having a capacity corresponding to the difference between the cooling capacity when the load on the mold F is minimum and the capacity of the electric heater to increase the continuous operation of the compressor. In addition, since the electric heater capable of controlling the capacity is provided, the manufacturing cost increases accordingly, and the electric power for heating the cold water supplied to the mold F in addition to the electric power supplied to the compressor is reduced. There were also issues that needed to be addressed.

In the present invention, when cooling the mold by supplying cold water to the mold, generally, cold water cooled to about 10 to 15 ° C. is used. It was invented with a focus on the fact that the temperature of cold water supplied to the mold can be easily obtained by using well water of about 18 ° C. or industrial water, and replenishing the water can increase the temperature of cold water supplied to the mold. The compressor can be continuously operated without using a cooling tank or a chilled water tank as in the conventional example and without using an electric heater, and the temperature of the chilled water supplied to the mold can be easily controlled. The point is that the amount can be constant and the whole can be downsized.

[0006]

According to the present invention, a chilled water chiller unit 5 having a compressor 1, a condenser 2 and an evaporator 3 for cooling water by the evaporator 3 is provided. Supply pipe 9 and return pipe 10 for connecting a mold 8 having a section 6 and an outflow section 7 to the cold water chiller unit 5
And supplying cold water from the cold water chiller unit 5 to the inflow section 6 through the supply pipe 9,
A cooling device for a molding die, which circulates the water after cooling the die back to the cold water chiller unit 5, wherein a temperature detector 13 for detecting the temperature of the cold water supplied to the die 8 is provided; On the discharge side of the pump 14 interposed in the return pipe 10, a water discharge pipe 16 which interposes a first on-off valve 15 and discharges water from the return pipe 10 when the first on-off valve 15 is opened. Along with the connection, a replenishing water pipe 17 for replenishing the return pipe 10 with water corresponding to the amount of water discharged from the water discharge pipe 16 is connected to the suction side of the pump 14, and the temperature detected by the temperature detector 13 is set to When the temperature is below the set temperature, the first
A controller 18 for opening the on-off valve 15 and adjusting the temperature of the cold water supplied to the mold 8 to a set temperature is provided.

The first on-off valve 15 is preferably constituted by a flow control valve for controlling the flow rate by controlling the opening degree, and an on / off solenoid valve for controlling the flow rate by controlling the opening time by turning on and off. Respectively.

[0008] Further, a water discharge return pipe 22 is provided which branches off from the water discharge pipe 16 and is connected to the downstream side of the makeup water flow of the check valve 21 interposed in the makeup water pipe 17.
It is preferable to interpose a second on-off valve 23 that operates according to the difference between the temperature detected by the temperature detector 13 and the set temperature.

Further, the water discharge pipe 16 is connected to the cooling water inlet pipe 30 of the condenser 2, and the cooling water outlet pipe 3 of the condenser 2 is connected.
It is preferable to connect the makeup water pipes 17 to each other.

The set temperature has a temperature range of about ± 1 ° C., for example.

[0011]

When the load on the mold 8 decreases, the temperature of the water after cooling the mold 8 decreases, and the temperature of the cold water supplied to the inflow portion 6 of the mold 8 decreases to the lower limit of the set temperature. , The temperature detector 13 detects this temperature drop, the first on-off valve 15 is opened by the output of the controller 18, water is discharged from the water discharge pipe 16, and the water discharge pipe is discharged. Since water corresponding to the amount of water discharged from the supply pipe 16 can be supplied from the supply water pipe 17 to the return pipe 10, the temperature of the water supplied from the supply water pipe 17 decreases when the load on the mold 8 decreases. When using well water, for example, at 18 ° C. higher than the temperature of the water after cooling the mold 8, the temperature of the water returning to the inlet 12 of the cold water chiller unit 5 can be increased and supplied to the mold 8. To raise the temperature of the cold water It can be adjusted to a set temperature.

Therefore, when the load on the mold 8 is reduced, the temperature of the water returning to the inlet 12 of the chilled water chiller unit 5 is increased, and the temperature of the chilled water supplied to the mold 8 is increased. Because it can be adjusted to the set temperature,
Temperature control can be performed without using a large chilled water tank, a cooling tank, an electric heater or the like as in the conventional example.
It is possible to reduce the size while continuously operating without frequent starting and stopping.

When a flow control valve for controlling the flow rate by controlling the opening degree is used as the first on-off valve 15, the flow rate of the water discharged from the water discharge pipe 16 is determined by repeating the opening and closing of the first on-off valve 15. Therefore, the temperature rise of the cold water supplied to the mold 8 can be easily and accurately adjusted.

When an on / off solenoid valve for adjusting the flow rate by opening / closing control of the on / off time is used as the first on / off valve 15, the on / off control can be performed at a lower cost than the flow control valve. In this case, the flow rate of the water discharged from the water discharge pipe 16 can be adjusted, and the temperature of the cold water can be effectively controlled.

Further, a water discharge return pipe 22 is provided, which branches off from the water discharge pipe 16 and is connected to the downstream side of the makeup water flow of the check valve 21 interposed in the makeup water pipe 17.
When the second on-off valve 23 that operates according to the difference between the temperature detected by the temperature detector 13 and the set temperature is interposed, when the second on-off valve 23 is operated, the supply water pipe 17 is returned to the return pipe 10.
Since the amount of water to be supplied to the mold 8 can be reduced as compared with the case where only the first opening / closing valve 15 is opened, only the first opening / closing valve 15 operates to increase the temperature of the cold water supplied to the mold 8. Can be slower than in the case. Therefore, the hunting of the temperature control can be reduced accordingly, and the control accuracy can be improved.

When the water discharge pipe 16 is connected to the cooling water inlet pipe 30 of the condenser 2, the first water discharge pipe 16
When the on-off valve 15 is opened, a part of the low-temperature chilled water flowing from the pump 14 to the inlet 12 of the chilled water chiller unit 5 is transferred to the cooling water inlet of the condenser 2 through the water discharge pipe 16. Since the refrigerant gas can flow into the pipe 30, the refrigerant gas can be efficiently condensed in the condenser 2. Accordingly, energy saving can be realized by effectively utilizing the cold heat of the cold water discharged from the water discharge pipe 16. can do.

Further, when the makeup water pipe 17 is connected to the cooling water outlet pipe 31 of the condenser 2, the water having a higher temperature in the condenser 2 is supplied to the cooling water outlet pipe 31 of the condenser 2.
Can be supplied to the return pipe 10 through the supply water pipe 17 and flow into the inlet 12 of the evaporator 3, that is, the cold water supplied to the mold 8 by utilizing the condensed waste heat. The control can be performed by efficiently raising the temperature, and the temperature of the cold water can be controlled even when well water or industrial water cannot be obtained.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first embodiment shown in FIG. 1, a compressor 1, a condenser 2 and an evaporator 3 are connected by a refrigerant pipe 4, and water passing through the evaporator 3 when the compressor 1 is operated. To 10
Using a cold water chiller unit 5 that cools to 15 ° C., a mold 8 having an inflow portion 6 and an outflow portion 7 is connected to the cold water chiller unit 5 via a supply pipe 9 and a return pipe 10. The cold water cooled in step 3 is supplied from the outlet 11 of the cold water chiller unit 5 to the inlet 6 of the mold 8 via the supply pipe 9 and flows out of the outlet 7 after cooling the mold 8. The returning water is returned to the inlet 12 of the cold water chiller unit 5 through the return pipe 10.

Thus, in the mold cooling apparatus constructed as described above, the temperature detector 13 for detecting the temperature of the cold water supplied to the mold 8 is provided, while the pump 14 interposed in the return pipe 10 is provided. A first on-off valve 15 is interposed on the discharge side of the valve, and the return pipe 10 is opened when the first on-off valve 15 is opened.
A water supply pipe 1 for connecting the water discharge pipe 16 for discharging water from the water supply pipe to the return side of the return pipe 10 with water corresponding to the amount of water discharged from the water discharge pipe 16 to the suction side of the pump 14.
7, a controller 18 that opens the first on-off valve 15 when the temperature detected by the temperature detector 13 is equal to or lower than a set temperature, and adjusts the temperature of the cold water supplied to the mold 8 to the set temperature. It was provided.

That is, as shown in FIG. 1, the temperature detector 13 is provided in the supply pipe 9 near the outlet 11 of the chilled water chiller unit 5, and the chilled water flowing from the outlet 11 to the inlet 6 is provided. Is detected, and this temperature is output to the input side of the controller 18.

Further, the pump 14 inserted in the middle of the return pipe 10 receives the inlet 1 of the cold water chiller unit 5.
The water discharge pipe 16 provided with the first opening / closing valve 15 and the variable throttle valve 19 is branched from the middle of the return pipe 10 reaching 2,
The first on-off valve 1 is set by setting the throttle valve 19 to a predetermined throttle amount.
At the time of the opening operation of 5, a predetermined amount, for example, 40 liters / minute of water is discharged from the water discharged from the pump 14.

Also, a header 20 is interposed in the return pipe 10 from the outlet 7 of the mold 8 to the pump 14, and the makeup water pipe 17 with a check valve 21 interposed in the header 20. When connecting and discharging 40 liters / minute of water from the water discharge pipe 16, water corresponding to the amount of water discharged from the water discharge pipe 16, that is, 40 liters / minute of water is supplied from the makeup water pipe 17 to the header 20. Through the return pipe 1
In this case, well water having a temperature of about 18 ° C. throughout the year and a temperature higher than the temperature of water (10 to 15 ° C.) supplied to the mold 8 is supplied. . The temperature of industrial water is 15 ° C in winter.
Since it is used at about 25 ° C. in summer, industrial water may be supplied instead of well water.

Further, in the embodiment shown in FIG. 1, the water discharge return pipe 22 branches off from the middle of the first on-off valve 15 and the throttle valve 19 interposed in the water discharge pipe 16, and the water discharge return pipe 22
In addition, a second opening / closing valve 23 that operates according to the difference between the temperature detected by the temperature detector 13 and the set temperature is interposed with a variable throttle valve 24 and a check valve 25, and the tip thereof is connected to the makeup water pipe. 17 is connected to the downstream side of the makeup water flow of the check valve 21, the throttle valve 24 is set to a predetermined throttle amount, and when the second on-off valve 23 operates, the discharge pipe 16
A predetermined amount of water, for example, 20 liters /
That is, the water is returned to the suction side of the pump 14 through the water return pipe 22.

Reference numeral 26 denotes a bypass valve which is opened when the appropriate flow rate of the chilled water chiller unit 5 is larger than the required flow rate of the mold 8.

The controller 18 includes, for example, a central processing unit (not shown) therein, and has the input side connected to the temperature detector 13 as described above, and the output side connected to the first and second sensors. The on-off valves 15 and 23 are respectively connected to calculate a temperature difference between the temperature detected by the temperature detector 13 and a set temperature, and a first difference is calculated based on the calculation result.
Only the on-off valve 15 is opened, and the first and second
By changing the amount of water supplied from the supply water pipe 17 by opening and closing the on-off valves 15 and 23, the temperature rising speed of the cold water supplied to the mold 8 is changed.

The cooling capacity of the chilled water chiller unit 5 is, for example, 30,000 kcal / h, and the capacity of the pump 14 is such that the flow rate of the chilled water flowing through the supply pipe 9 and the return pipe 10 is, for example, 200 l / min. And the set temperature, which is the control reference for the chilled water cooled by the chilled water chiller unit 5, is set in the range of 10 to 15 ° C., for example, 10 ° C. Is set to a temperature range of ± 1 ° C., that is, 2 ° C. with respect to the set temperature, and when the set temperature is 10 ° C., the opening operation is performed at 9 ° C. and the closing operation is performed at 11 ° C.

Further, in the embodiment shown in FIG.
The on-off valve 15 is an electromagnetic valve that performs an on / off operation, and a variable throttle valve 19 is used for the water discharge pipe 16 together with the first on-off valve 15. In addition, the second opening / closing valve 23 also uses an electromagnetic valve that is turned on and off, and the return amount from the water discharged is adjusted to, for example, 20 liter / minute by the throttle amount of the variable throttle valve 24. .

When only the first opening / closing valve 15 is opened, water is discharged from the water discharge pipe 16 at a rate of 40 liters / minute, and the first and second opening / closing valves 15 and 23 are both opened. At this time, of the 40 liters / minute of water flowing through the water discharge pipe 16, 20 liters / minute of water will merge with the header 20 via the water discharge return pipe 22. The flow rate of water can be changed from 40 l / min to 20 l / min.

Therefore, if the load on the mold 8 is reduced while cooling the mold 8 by supplying cold water to the mold 8, the temperature rise of the water after cooling the mold 8 is small. The temperature of the chilled water supplied from the chilled water chiller unit 5 to the inlet 6 of the mold 8 is reduced. When the temperature of the chilled water drops to 9 ° C., the temperature detector 13 detects this temperature drop, and outputs the first
The on-off valve 15 is opened and water is discharged from the water discharge pipe 16 at a flow rate of 40 liters / minute, and an amount of water corresponding to this flow rate, that is, water at a flow rate of 40 liters / minute, is supplied from the makeup water pipe 17. It is supplied to the return pipe 10,
By using well water having a temperature of 18 ° C. as water to be supplied from the supply water pipe 17, the cold water chiller unit 5 can be used.
The temperature of the water returning to the inlet 12 can be increased, and the temperature of the cold water supplied to the mold 8 can be increased.

As described above, the water discharge from the water discharge pipe 16 at a flow rate of 40 liters / minute and the supply water pipe 17
When the temperature of the chilled water supplied to the mold 8 continues to rise to 11 ° C. by continuing the supply of the well water at a flow rate of 40 liters / minute from the above, the first opening / closing valve 15 is controlled by the controller 18. After closing and cooling the mold 8, the whole amount of water is returned to the inlet 12 of the cold water chiller unit 5, and the temperature of the cold water supplied to the inlet 6 of the mold 8 can be reduced. .

As described above, according to the first embodiment, the temperature of the water after cooling the mold 8 decreases due to the decrease in the load on the mold 8 and the inflow portion 6 of the mold 8 When the temperature of the chilled water supplied to the heater exceeds the set temperature and drops to 9 ° C., the temperature detector 13 detects this temperature drop, and the output of the controller 18 causes the first on-off valve 15 to open to operate. 40 liters / minute of water is discharged from the water discharge pipe 16 and water corresponding to the amount of water discharged from the water discharge pipe 16, that is, 40 liters / minute of water is supplied to the makeup water pipe 1.
7, the temperature of the water returning to the inlet portion 12 of the chilled water chiller unit 5 can be increased, and the temperature of the chilled water supplied to the mold 8 can be set to a set temperature. On the other hand, it can be adjusted within a range of ± 1 ° C.

Further, since the temperature of the chilled water from the chilled water chiller unit 5 can be adjusted to a predetermined temperature range with respect to the set temperature by using make-up water, a large chilled water tank, a cooling tank, an electric Temperature control can be performed without using a heater or the like. Therefore, the compressor 1 can be continuously operated without frequent starting and stopping, and can be reduced in size.
When 40 liter / min of water is discharged from the water discharge pipe 16, 40 liter / min of water is supplied to the makeup water pipe 17
Can be supplied to the return pipe 10, so that the circulation amount can be made constant.

When the first on-off valve 15 is opened and the second on-off valve 23 is opened using the water discharge return pipe 22, the amount of water to be supplied from the make-up water pipe 17 to the return pipe 10. Can be reduced as compared with the case where only the first opening / closing valve 15 is opened. Therefore, the temperature rise of the cold water supplied to the mold 8 is delayed as compared with the case where only the first opening / closing valve 15 is opened. can do. Therefore, hunting in temperature control can be reduced accordingly, and control accuracy can be improved.

The load on the mold 8 varies depending on the mold 8 and its use conditions. However, if the type, size and use conditions of the mold 8 are determined, the load, in other words, the load on the refrigeration capacity, is increased. The rate will also be determined.

The temperature of make-up water supplied from the make-up water pipe 17 can be substantially constant in the case of well water, but changes between winter and summer in the case of industrial water. Therefore, when the load factor is 30% and 60%, and when the temperature of the makeup water changes between 20 ° C. and 30 ° C., the opening / closing control of the first on-off valve 15 and the second on-off valve 23 is performed. When the chilled water temperature is examined, the chilled water temperature change characteristic shown in FIG. 2 is obtained.

In FIG. 2, the horizontal axis represents time (seconds), and the vertical axis represents chilled water temperature (° C.). The solid line A and the dotted line B indicate that the load factor is 30% of the refrigeration capacity of the chilled water chiller unit 5. The one-dot chain line C and the two-dot chain line D show the temperature change of the chilled water when the load factor is 60%. In addition, in each of these temperature change characteristics, the opening and closing of the first and second on-off valves 15 and 23 are controlled as shown in Table 1.

[0037]

[Table 1]

That is, the solid line A indicates the case where only the first on-off valve 15 is opened when the cold water temperature drops to 9 ° C., and water at 20 ° C. is supplied from the replenishing water pipe 17 at a flow rate of 40 liter / min. It shows a temperature change. Also, the dotted line B
Opens the first and second on-off valves 15 and 23 when the temperature of the cold water drops to 9 ° C., and discharges 20 liters / water of 30 ° C.
It shows a temperature change when replenishing water from the replenishing water pipe 17 at a minute flow rate.

The dashed line C indicates that when the temperature of the cold water drops to 9 ° C., only the first opening / closing valve 15 is opened, that is, the water at 20 ° C. is supplied at a flow rate of 40 liters / min. 17, the temperature of the cold water dropped to 9 ° C. is raised, and when the temperature of the cold water rises from 9 ° C. to 11 ° C., the first and second on-off valves 15, 2
3 shows an opening operation, that is, a temperature change when the temperature of the chilled water that has risen to 11 ° C. is lowered while replenishing water at 20 ° C. from the makeup water pipe 17 at a flow rate of 20 liters / minute. The two-dot chain line D indicates that the first and second on-off valves 15 and 23 are opened when the cold water temperature drops to 9 ° C., that is, the water at 30 ° C. is supplied at a flow rate of 20 liter / min. The temperature of the chilled water dropped to 9 ° C. by the replenishment from the water pipe 17 was raised, and
When the temperature rises from 11 ° C. to 11 ° C., the first and second on-off valves 15 and 23 are closed, that is, without replenishing from the make-up water pipe 17 and without controlling the temperature of the cold water rising to 11 ° C. It shows a temperature change when the temperature is lowered by cooling by the chiller unit 5.

However, as is apparent from the above-described change in the cold water temperature, when the load factor is 30% and the make-up water temperature is 20 ° C., even if the water discharge return pipe 22 is closed, that is, Even if the water volume is 40 liters / minute, the temperature rise is slow. However, when the temperature of the makeup water reaches 30 ° C., the temperature rise of the cold water, although not shown, is rapid. By opening the on-off valve 23 and adjusting the amount of water discharged and the amount of makeup water to 20 liters / minute, the temperature rise of the cold water can be made slower than in the case where it is not returned.

When the load factor is changed from 30% to 60%, the temperature of the chilled water decreases more slowly than when the load factor is 30%. Chain line D
If the second opening / closing valve 23 is not opened, the temperature rises further (not shown). Therefore, when the load factor is high, it is better to open the second on-off valve 23 for the first and second on-off valves 1.
It turns out that the frequency of opening and closing of 5, 23 decreases.

In the dashed line C, the replenishment water temperature is 20
° C, the temperature of the replenishing water is 30 ° C even when the second on-off valve 23 is closed, and the temperature rise is somewhat slower than the two-dot chain line D in which the second on-off valve 23 is opened. Therefore, when the temperature of the chilled water is controlled to rise, the temperature can be controlled to be slow by opening only the first on-off valve 23 and opening the second on-off valve 23 after the chilled water temperature reaches the upper limit of 11 ° C.

Therefore, the first
When controlling the opening and closing of the second on-off valves 15 and 23, it is preferable that a load factor and a make-up water temperature known in advance are input to the controller 18 so that the opening and closing control can be performed based on the load factor and the make-up water temperature. In the first embodiment, the throttle valve 19 interposed in the water discharge pipe 16 is set to a predetermined throttle amount, and when the first on-off valve 15 is opened, the water discharge pipe 1
The flow rate of water discharged from 6 was set to 40 l / min,
Instead of an electromagnetic valve, a flow rate control valve for adjusting the flow rate by opening control may be used, or the flow rate may be adjusted by opening time control by pulse control.

In any case, the water discharge amount and the makeup water amount can be controlled according to the cold water temperature from the temperature detector 13.
It is possible to precisely control the temperature of the cold water.

When adjusting the flow rate, it is not necessary to provide a temperature range for the set temperature, so that the chilled water temperature can be controlled to the set temperature.

In the case where the flow rate is adjusted by controlling the opening time of the first on-off valve 15 as a solenoid valve by pulse control using a flow control valve, the cost is lower than using a flow control valve. When a flow control valve that can linearly adjust the degree of opening is used, the flow rate of the water discharged from the water discharge pipe 16 can be adjusted without repeating the opening and closing of the on-off valve 15. There is no problem, and the temperature rise of the cold water supplied to the mold 8 can be adjusted with higher precision.

In the first embodiment described above, the water discharged from the water discharge pipe 16 is drained without using it. However, as in the second embodiment shown in FIG. May be used, or the waste heat of condensation of the condenser 2 may be used.

In the second embodiment shown in FIG. 3, the cooling water inlet pipe 30 is connected to the condenser 2 connected to the discharge side of the compressor 1.
And the cooling water outlet pipe 31, and the water discharge pipe 16 to the cooling water inlet pipe 30.
During the opening operation, the water can be discharged to the cooling water inlet pipe 30. When the water supply pipe 17 is connected to the cooling water outlet pipe 31 of the condenser 2 and water is discharged from the water discharge pipe 16, the cooling water outlet pipe 3 is connected via the water supply pipe 17.
Water can be supplied to the return pipe 10 from 1.

In the second embodiment constructed as described above, the load on the mold 8 is reduced, the temperature of the chilled water supplied to the inlet 6 of the mold 8 is reduced, and the output of the controller 18 When the first on-off valve 15 interposed in the water discharge pipe 16 is opened, the low-temperature water discharged from the water discharge pipe 16 flows into the cooling water inlet pipe 30 of the condenser 2. In addition, high-temperature water discharged from the cooling water outlet pipe 31 is supplied via the header 20, and the temperature of the cold water supplied to the inflow portion 6 of the mold 8 may be increased by the supplied water. You can.

Therefore, when the first on-off valve 15 interposed in the water discharge pipe 16 is opened, a part of the low-temperature cold water flowing from the pump 14 into the inlet 12 of the cold water chiller unit 5 is removed. The condenser 2 is connected via a water discharge pipe 16.
, The refrigerant gas can be efficiently condensed in the condenser 2, so that the cold heat of the cold water discharged from the water discharge pipe 16 can be effectively used. Energy can be realized, and water whose temperature has increased in the condenser 2 can be transferred from the cooling water outlet pipe 31 of the condenser 2 to the return pipe 10 via the makeup water pipe 17.
Can be supplied to the inlet 12 of the evaporator 3, that is, the temperature of the cold water supplied to the mold 8 can be efficiently increased by utilizing the condensed waste heat, and the temperature control can be performed. Therefore, even when well water or industrial water cannot be obtained, the temperature of the cold water can be easily controlled.

In the second embodiment, the cooling water inlet pipe 3
0, and the make-up water pipe 17 is connected to the cooling water outlet pipe 31 at the same time. However, while the water discharge pipe 16 is connected to the cooling water inlet pipe 30, the cooling water outlet pipe The supply water pipe 17 may not be connected to the cooling water outlet pipe 31, and the water discharge pipe 16 may be connected to the cooling water inlet pipe 30 while the makeup water pipe 17 is connected to the cooling water outlet pipe 31. You do not need to connect. Further, similarly to the first embodiment, a water discharge return pipe having a second on-off valve may be provided.

Further, as described in the first embodiment, the first on-off valve 15 interposed in the water discharge pipe 16 is provided with a flow control valve for controlling the flow rate by controlling the opening degree, and an open time control by ON / OFF. Alternatively, an on / off solenoid valve for adjusting the flow rate may be used.

Further, a cooling tower 32 may be connected to the cooling water inlet pipe 30 and the cooling water outlet pipe 31 of the condenser 2, but a structure in which well water or tap water flows through the cooling water inlet pipe 30. It is preferable to use the method described above because it is possible to prevent intrusion of dust and the like from the atmosphere.

[0054]

As described above, according to the present invention, a cold water chiller unit 5 having a compressor 1, a condenser 2 and an evaporator 3 for cooling water by the evaporator 3, an inflow section 6 and an outflow section 7 and a supply pipe 9 and a return pipe 10 for connecting the mold 8 with the cold water chiller unit 5 to the cold water chiller unit 5. Cold water from the cold water chiller unit 5 is supplied to the inflow section 6 through the supply pipe 9. A cooling device for a molding die that supplies and circulates water after cooling the die from the outflow portion 7 back to the cold water chiller unit 5, wherein a temperature for detecting the temperature of the cold water supplied to the die 8. While a detector 13 is provided, a first on-off valve 1 is provided on the discharge side of a pump 14 interposed in the return pipe 10.
5, and a water discharge pipe 16 for discharging water from the return pipe 10 when the first opening / closing valve 15 is opened, and discharging water from the water discharge pipe 16 to the suction side of the pump 14. A replenishing water pipe 17 for supplying water corresponding to the amount of water discharged to the return pipe 10 is connected, and when the temperature detected by the temperature detector 13 is equal to or lower than a set temperature, the first on-off valve 15 is opened, and the mold is opened. Since the controller 18 for adjusting the temperature of the chilled water supplied to the mold 8 to the set temperature is provided, the temperature of the water after cooling the mold 8 decreases due to a decrease in the load of the mold 8, and When the temperature of the chilled water supplied to the inflow section 6 decreases to the lower limit of the set temperature, the temperature detector 1
3 detects this temperature drop, the first on-off valve 15 is opened by the output of the controller 18, the water is discharged from the water discharge pipe 16, and the amount corresponds to the amount of water discharged from the water discharge pipe 16. Can be replenished from the replenishing water pipe 17 to the return pipe 10, so that the temperature of the water replenished from the replenishing water pipe 17 decreases after the mold 8 cools when the load on the mold 8 decreases. Higher than the temperature of the water eg 1
When using well water at 8 ° C., the cold water chiller unit 5
The temperature of the water returning to the inlet portion 12 can be increased, and the temperature of the cold water supplied to the mold 8 can be increased to adjust to the set temperature.

Therefore, when the load on the mold 8 decreases, the temperature of the water returning to the inlet 12 of the chilled water chiller unit 5 is increased, and the temperature of the chilled water supplied to the mold 8 is increased to a predetermined value. Because it can be adjusted to the set temperature,
Temperature control can be performed without using a large chilled water tank, a cooling tank, an electric heater, and the like as in the conventional example. Therefore, the compressor 1 can be downsized while continuous operation can be performed without frequent starting and stopping. is there. Further, when water is discharged from the water discharge pipe 16, water corresponding to the amount of water discharged from the water discharge pipe 16 can be supplied from the supply water pipe 17 to the return pipe 10, so that the circulation amount can be kept constant. When a flow control valve that adjusts the flow rate by controlling the opening degree is used as the first on-off valve 15, the flow rate of water discharged from the water discharge pipe 16 is adjusted without repeating opening and closing of the first on-off valve 15. The temperature rise of the cold water supplied to the mold 8 can be easily and accurately adjusted.

When an ON / OFF solenoid valve for adjusting the flow rate by ON / OFF control of the opening time is used as the first opening / closing valve 15, the opening / closing control is simply performed while reducing the cost as compared with the flow regulating valve. The drain pipe 1 compared to the case
The flow rate of the water discharged from 6 can be adjusted, and the temperature control of the cold water can be effectively performed.

Further, a water discharge return pipe 22 branched from the water discharge pipe 16 and connected to the downstream side of the makeup water flow of the check valve 21 interposed in the makeup water pipe 17 is provided.
When the second on-off valve 23 that operates according to the difference between the temperature detected by the temperature detector 13 and the set temperature is interposed, when the second on-off valve 23 is operated, the supply water pipe 17 is returned to the return pipe 10.
Since the amount of water to be supplied to the mold 8 can be reduced as compared with the case where only the first opening / closing valve 15 is opened, only the first opening / closing valve 15 operates to increase the temperature of the cold water supplied to the mold 8. Can be slower than in the case. Therefore, the hunting of the temperature control can be reduced accordingly, and the control accuracy can be improved.

When the water discharge pipe 16 is connected to the cooling water inlet pipe 30 of the condenser 2, the first water discharge pipe 16
When the on-off valve 15 is opened, a part of the cold water having a low temperature flowing from the pump 14 to the inlet 12 of the cold water chiller unit 5 is supplied to the cooling water inlet of the condenser 2 through the water discharge pipe 16. Since the refrigerant gas can flow into the pipe 30, the refrigerant gas can be efficiently condensed in the condenser 2. Accordingly, energy saving can be realized by effectively utilizing the cold heat of the cold water discharged from the water discharge pipe 16. can do.

Further, when the makeup water pipe 17 is connected to the cooling water outlet pipe 31 of the condenser 2, the water whose temperature has become high in the condenser 2 is supplied from the cooling water outlet pipe 31 of the condenser 2. Replenish to the return pipe 10 via the water pipe 17,
Since it can flow into the inlet 12 of the evaporator 3, that is, it is possible to efficiently raise the temperature of the cold water supplied to the mold 8 by using the condensed waste heat and perform the temperature control. Even when industrial water cannot be obtained, the temperature of the cold water can be easily controlled.

[Brief description of the drawings]

FIG. 1 is a piping diagram of a cooling device for a molding die to which the present invention is applied.

FIG. 2 is a graph showing an opening / closing operation of first and second on-off valves and a change characteristic of chilled water temperature.

FIG. 3 is a piping diagram showing a second embodiment.

FIG. 4 is a piping system diagram showing a conventional example.

FIG. 5 is a piping diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Evaporator 5 Cold water chiller unit 6 Inflow part 7 Outflow part 8 Die 9 Supply pipe 10 Return pipe 13 Temperature detector 14 Pump 15 First on-off valve 16 Water discharge pipe 17 Supply water pipe 18 Controller 22 Water discharge return Pipe 23 second on-off valve 30 cooling water inlet pipe 31 cooling water outlet pipe

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-99311 (JP, A) JP-A-59-57714 (JP, A) JP-A-5-329853 (JP, A) JP-A-62 240150 (JP, A) JP-A 1-125609 (JP, U) JP 3-35091 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 33/04

Claims (6)

(57) [Claims] 1. A cold water chiller unit 5 having a compressor 1, a condenser 2 and an evaporator 3 for cooling water by the evaporator 3, a mold 8 having an inflow portion 6 and an outflow portion 7, and Supply pipe 9 and return pipe 10 for connecting to cold water chiller unit 5
And supplying cold water from the cold water chiller unit 5 to the inflow section 6 through the supply pipe 9,
A cooling device for a molding die, which circulates the water after cooling the die back to the cold water chiller unit 5, wherein a temperature detector 13 for detecting the temperature of the cold water supplied to the die 8 is provided; On the discharge side of the pump 14 interposed in the return pipe 10, a water discharge pipe 16 which interposes a first on-off valve 15 and discharges water from the return pipe 10 when the first on-off valve 15 is opened. Along with the connection, a replenishing water pipe 17 for replenishing the return pipe 10 with water corresponding to the amount of water discharged from the water discharge pipe 16 is connected to the suction side of the pump 14, and the temperature detected by the temperature detector 13 is set to When the temperature is below the set temperature, the first
A cooling device for a molding die, comprising a controller 18 for opening the on-off valve 15 and adjusting the temperature of cold water supplied to the die 8 to a set temperature. 2. The cooling device for a molding die according to claim 1, wherein the first on-off valve comprises a flow rate control valve for controlling a flow rate by controlling the opening degree. 3. The cooling device for a molding die according to claim 1, wherein the first opening / closing valve 15 is an on / off solenoid valve for adjusting a flow rate by opening / closing time control by on / off. 4. A water discharge return pipe 22 branched from the water discharge pipe 16 and connected to a downstream side of a makeup water flow of a check valve 21 interposed in the makeup water pipe 17 is provided. The cooling device for a molding die according to claim 1, further comprising a second on-off valve (23) that operates according to a difference between the temperature detected by the detector (13) and the set temperature. 5. A water discharge pipe 1 is connected to a cooling water inlet pipe 30 of the condenser 2.
6. The cooling device for a molding die according to claim 1, wherein said cooling device is connected to said cooling device. 6. The cooling device for a molding die according to claim 1, wherein the supply water pipe 17 is connected to the cooling water outlet pipe 31 of the condenser 2.