JP5706969B2 - Mold temperature control system - Google Patents

Description

  The present invention relates to a temperature adjustment system for controlling a synthetic resin molding die to a desired set temperature. In particular, the present invention relates to a temperature control system for a molding die that can use a desired mold temperature over a wider temperature range than before by utilizing waste heat of the mold and cold heat from a cooler. Is.

Conventionally, in plastic molding, a molten resin injected from a molding machine into a mold is cooled and solidified in the mold, and after sufficiently cooled, taken out of the mold to produce a plastic molded product.
As a means for cooling the mold, a method of circulating the coolant cooled by the cooling device to the mold is employed. Temperature control is generally performed so that the mold temperature matches the molding temperature by providing a circulation flow path through which the coolant flows inside the mold and maintaining the coolant at a constant temperature. The mold temperature is generally controlled within a range of 10 ° C. to 30 ° C. (hereinafter also referred to as “low temperature region”) according to the heat deformation temperature of the resin to be molded.
However, in the case of a resin having a high heat distortion temperature, the mold temperature is to be maintained at a room temperature or higher, for example, 40 ° C. to 60 ° C. (hereinafter also referred to as “medium temperature range”) like EVA resin or ABS resin. There is. In such a case, a cooling system using only the coolant circulation circuit as described above cannot cope.

  Therefore, the present applicant has proposed a temperature control system for a molding die as shown in Patent Document 1. According to the present invention, by utilizing the waste heat of the mold and the cold heat from the cooler, the desired mold temperature can be used efficiently and efficiently from the low temperature range of 10 ° C. to the middle temperature range of around 60 ° C. become able to.

Japanese Patent No. 4775577

However, there are cases where it is desired to maintain the mold temperature in a high temperature range of about 90 ° C. like polycarbonate resin. In that case, it was difficult to maintain the coolant at 90 ° C. only by using the waste heat of the mold as described above.
Therefore, the present invention makes it possible to use a desired mold temperature from a low temperature range to an intermediate temperature range by utilizing waste heat of the mold and cold heat from a cooler, and further to a higher temperature range (that is, 10 ° C. to 90 ° C.). The main object of the present invention is to provide a temperature control system for a molding die that can be used stably over a temperature range of [° C.] with a simple configuration.

  Further, when the cooler is used, power is consumed, but the power charge is set to be cheaper at night when the power usage is lower than during the day when the power usage peaks. Therefore, it is possible to store the cold heat by generating ice by operating the cooler at night when the electricity rate is cheap, and it is possible to control the temperature while melting the ice at the peak of daytime power usage and saving power A temperature control system is desired, but in the conventional temperature control system, the usage state of the device is changed to a mode that efficiently generates ice, or a mode that efficiently uses the generated ice to save power There has been no contrivance that can be easily changed. An object of the present invention is to provide a temperature control system that can easily and efficiently perform ice temperature generation and actively melt ice while performing temperature control operation. .

In order to achieve the above object, in the temperature control system for a molding die according to the present invention, a cooling device including an evaporator capable of cooling the cooling liquid and generating ice by cooling the cooling liquid. And an upstream cooling space and a downstream liquid feeding space are provided so as to communicate with each other, and the evaporator of the cooling device is disposed in the cooling space and stores the cooling liquid cooled by the evaporator A tank, a regulating tank that stores the coolant fed from the liquid feeding space of the cooling tank, a coolant circulation channel that returns from the regulation tank to the regulation tank through a mold, and the coolant circulation channel A branch flow path branched from the middle of the cooling tank to the cooling space of the cooling tank , a control valve provided in the middle of the branch flow path, and the temperature of the coolant in the adjustment tank or the coolant circulation path The first temperature sensor for detecting When provided in the adjusting tank or the cooling fluid circulation passage, with a ON / OFF operation control function by comparing the detected temperature with a preset heating start set temperature of the first temperature sensor consists of a heater, the heater the temperature detected by the first temperature sensor is turned oN and becomes equal to or less than the heating start temperature setting, becomes more than the heating start temperature setting is formed to OFF operation, the first When the detected temperature of the temperature sensor becomes equal to or higher than a preset cooling start set temperature, the control valve is opened so that a part of the high-temperature coolant in the coolant circulation passage is returned to the cooling space of the cooling tank. It is formed on the low-temperature cooling liquid to the adjusting tank from the liquid feed space of only the amount of liquid returned to the cooling space of the cooling chamber the cooling bath is formed so as to flow, the said cooling tank tone And a second temperature sensor for detecting a temperature of the cooling liquid in the cooling tank in the vicinity of a boundary between the cooling space and the liquid feeding space of the cooling tank. Provided to control the cooling device according to the temperature detected by the second temperature sensor to control the temperature of the cooling liquid in the cooling tank and to control ice generation in the cooling space. It was set as the structure.

Since the present invention is configured as described above, the mold is cooled by the circulation of the cooling liquid in the adjustment tank separated from the cooling tank, and the circulating cooling liquid is set to a predetermined cooling start temperature or higher by the mold temperature. As a result, a part of the high-temperature coolant in the coolant circulation flow path is returned to the cooling tank, and the low-temperature coolant flows from the cooling tank into the adjustment tank by the amount of the returned liquid. The circulating coolant of the mold can be automatically adjusted to the set temperature, so that the temperature of the mold coolant can be reduced to a low temperature range of about 10 ° C by effectively using the waste heat of the mold and cooling by the cooling device. Can be obtained with energy saving up to about 60 ° C in the middle temperature range.
Furthermore, when resin molding is required at a temperature higher than 60 ° C., specifically about 90 ° C., such as a polycarbonate resin, a heater added to the system is used. Thereby, the temperature of the mold coolant in the adjustment tank can be raised to a high temperature of, for example, 90 ° C., and can be used even when resin molding is performed in a high temperature region such as a polycarbonate resin. Since the heater only needs to be attached in the middle of the adjustment tank or the circulation flow path, the structure is simple and the cost can be reduced.

In the present invention, the cooling reservoir and the adjustment reservoir are formed integrally structure that is divided by partition walls.
With this two-tank integrated structure, the entire tank can be made compact and the installation space can be reduced .
An evaporator of a cooling device that cools the cooling liquid is disposed inside the cooling tank, and ice is generated in the cooling space of the cooling tank by the evaporator.
Thereby, the evaporator is hidden and the appearance image becomes smart, and a large amount of cold energy can be stored by the ice generated in the cooling space of the cooling tank, so that the thermal efficiency can be increased.

And the 2nd temperature sensor which detects the temperature of the cooling fluid in the said cooling tank is provided in the boundary vicinity of the said cooling space and the said liquid feeding space of the said cooling tank, The detection temperature of the said 2nd temperature sensor Thus, the cooling device is controlled to control the temperature of the cooling liquid in the cooling tank and to control ice generation in the cooling space.
Accordingly, the mold can be constantly cooled by keeping the temperature of the coolant in the cooling tank constant by the second temperature sensor.
In addition, by providing the second temperature sensor in the vicinity of the boundary between the cooling space and the liquid feeding space, even if ice is generated on the surface of the screw tube of the evaporator, the periphery of the sensor temperature sensing unit maintains the aqueous phase. During this time, the second temperature sensor generally detects and displays the freezing point temperature (0 ° C.), so that ice generation can be continued. Further, when the ice which has grown and increased in thickness comes into contact with the sensor temperature sensing part, a low temperature below the freezing point is detected. Therefore, the generation of ice in the cooling space and the degree of growth can be monitored by the display temperature of the second temperature sensor.

In the above invention, the end portion of the branch flow path is branched into at least two to form a plurality of cooling tank connection flow paths, and one of the cooling tank connection flow paths is provided in the cooling space. One of the cooling tank connection channels is connected to an ice generating connection port provided in the liquid feeding space or a cooling space near the liquid feeding space, and the cooling fluid circulation flow is connected to the branch channel. You may provide the flow-path switching mechanism which switches the cooling tank connection flow path which sends the high temperature coolant from a path.
According to the present invention, ice is generated in the cooling space in which the evaporator of the cooling tank is arranged, or the generated ice is melted, but the position where the high-temperature coolant from the branch flow path is introduced into the cooling tank. A flow path switching mechanism is provided so that it can be changed between ice generation and ice melting.
That is, when ice is melted, in order to easily melt the ice generated in the cooling space, a high-temperature coolant is introduced toward the ice generated from the connection port (ice melting connection port) provided in the cooling space itself. .
In addition, when ice is generated, a connection port (ice generation connection) is provided in the liquid feeding space or in the cooling space near the liquid feeding space so that the cooling liquid as low as possible is placed near the evaporator in the cooling space to promote cooling. Coolant is introduced from the mouth .

In the above invention, the control valve may be provided on a flow path after the branch flow path is branched into each cooling tank connection flow path, and the control valve may also function as the flow path switching mechanism.
In addition, the control valve is provided on the upstream side of the branch flow path branching to each cooling tank connection flow path, and separately from the control valve, the flow switching for switching the flow path on each cooling tank connection flow path A mechanism may be provided.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which shows 1st Example of the metal mold | die temperature control system which concerns on this invention. The block diagram of 1st Example shown in FIG. Explanatory drawing which shows 2nd Example of the metal mold | die temperature control system which concerns on this invention. Explanatory drawing which shows 3rd Example of the metal mold | die temperature control system which concerns on this invention. Explanatory drawing which shows 4th Example of the metal mold | die temperature control system which concerns on this invention. Explanatory drawing which shows 5th Example of the metal mold | die temperature control system which concerns on this invention.

(Embodiment 1)
Below, the temperature control system of the metal mold | die for molding which concerns on this invention is demonstrated based on the Example shown on drawing.
FIG. 1 is an explanatory view showing a first embodiment of a temperature control system for a molding die according to the present invention, and FIG. 2 is a block diagram thereof. This temperature adjustment system includes a cooling tank 1 for storing a cooling liquid and an adjusting tank 2 for storing a cooling liquid from the cooling tank 1. The cooling tank 1 includes an upstream cooling space 1a and a downstream liquid feeding space 1b. The upstream side of the cooling space 1a is closed by a wall, and an evaporator 8 of the cooling device 5 described later is disposed in the space. The liquid feeding space 1b communicates with the downstream side of the cooling space 1a, and the cooling liquid cooled in the cooling space 1a is sent to the adjustment tank 2 through the liquid feeding space 1b.
The cooling tank 1 and the adjustment tank 2 are formed in a two-tank integrated structure separated by a partition wall 3, and are arranged so that the liquid level of the liquid feeding space 1 b of the cooling tank 1 is higher than the liquid level of the adjustment tank 2. The upper edge of the partition wall 3 of the cooling tank 1 is cut away to form an overflow port 4, and the overflow from the overflow port 4 is provided to flow into the adjustment tank 2.

Furthermore, in the temperature adjustment system of this invention, the cooling device 5 which cools a cooling fluid is provided. The cooling device 5 includes a compressor 6 that compresses a refrigerant such as chlorofluorocarbon, a condenser 7 that condenses the compressed refrigerant from the compressor 6, a screw-type evaporator (heat exchanger) 8, and a refrigerant circulation circuit 9 that connects these devices. The evaporator 8 is arranged inside the cooling space 1a of the cooling tank 1, and is configured to directly cool the cooling liquid in the cooling tank 1 by heat exchange.
The cooling device 5 is a heat pump type cooling device using the heat of evaporation of the refrigerant. This is configured not only to generate cold / hot water in the periphery of the screw tube of the evaporator 8 in the cooling tank 1 but also to set the temperature at which ice can be generated.
Accordingly, it is possible to store a large amount of cold using the latent heat (melting heat) of ice, that is, to store ice. As a result, the coolant temperature in the cooling bath 1 can be stably maintained at approximately 0 ° C., and the thermal efficiency can be increased. The cooling liquid in the cooling tank 1 is formed so as to maintain the cooling liquid temperature in the cooling tank 1 constant by controlling the cooling device 5 based on the temperature detected by the second temperature sensor 18 provided in the cooling tank 1. Has been.
The second temperature sensor 18 mounted on the cooling tank 1 is preferably installed at a position close to the screw tube surface of the evaporator 8 so that the temperature sensing part does not contact the screw tube. Specifically, the temperature sensing part of the second temperature sensor 18 may be installed at a position that is 1 cm to 10 cm, preferably 3 cm away from the screw tube surface of the evaporator 8 and that does not contact the tank wall surface. Further, the attachment position of the second temperature sensor 18 in the cooling space 1 a, preferably provided in the vicinity of the boundary between the cooling space 1a and feeding space 1b. By securing such an attachment position, even if ice is generated on the surface of the screw tube of the evaporator 8 , the second temperature sensor 18 is generally at the freezing point temperature ( since displaying 0 ° C.) detect and can continue the ice formation. When ice grows and increases its thickness and comes into contact with the sensor temperature sensing part, a low temperature below the freezing point is detected. As a result, ice formation and growth can be monitored from the display temperature of the second temperature sensor 18 .

  Further, the coolant circulation path 11 returns from the adjustment tank 2 to the adjustment tank 2 through the pump P and the mold 10 of the plastic molding machine, and is branched from the middle of the flow path to the mold 10 of the circulation path 11. A branch flow path 12 that reaches the cooling tank 1 and a first temperature sensor 15 that detects the temperature of the coolant in the adjustment tank 2 are provided. Further, a bypass channel 14 is provided that branches from the middle of the circulation channel 11 from the pump P to the mold 10 and returns to the adjustment tank 2, and a valve 16 is provided in the middle of the bypass channel 14.

The control valve 13 provided in the branch flow path 12 is normally closed. When the detected temperature of the coolant in the adjustment tank 2 by the first temperature sensor 15 is equal to or higher than a preset desired cooling start set temperature, the control valve 13 is opened and the flow reaching the cooling tank 1 of the branch flow path 12 When the passage is opened, a part of the cooling liquid in the circulation flow path 11 is returned to the cooling tank 1 via the branch flow path 12, and when the detected temperature becomes equal to or lower than the cooling start set temperature, the control valve 13 is closed to the cooling tank 1. The branch flow path 12 is set to be closed. The means for controlling such settings can be easily performed by a computer incorporating a control program. It can also be implemented by a combination of electronic control units.
The bypass flow path 14 is used for returning the coolant in the circulation flow path 11 to the adjustment tank 2 when a trouble occurs in the flow path in the mold 10 for some reason. The flow rate inside is appropriately adjusted by the valve 16, and the valve 16 is closed when the bypass flow path 14 is not required. Further, the bypass channel 14 can be omitted from the present system.

  In addition, the adjustment tank 2 is provided with a heater 17 that heats the cooling liquid in the adjustment tank 2 and the coolant circulation passage 11 when used in a high temperature range. The heater 17 is operated when the mold 10 needs to be cooled with a coolant in a high temperature range of 50 ° C. to 90 ° C. The temperature detected by the first temperature sensor 15 is set in advance. The temperature is set to be ON when the temperature is lower than a desired heating start set temperature, and OFF when the temperature is higher than the set temperature.

  Furthermore, in order to adjust the water level in the adjustment tank 2 to a constant level, the coolant supply channel 19 from the cold water tower 23 provided outside is communicated via the float valve 20, and the water level drops from the set value. The float 20a is moved downward to open the float valve 20, and the coolant from the cold water tower 23 is supplied to maintain the water level at a constant value.

  In addition, for the maintenance of the system and the cleaning of the cooling tank 1 and the adjustment tank 2, a reduction flow path 21 for returning the coolant in the system to the cold water tower 23 communicates with the cold water tower 23 from the middle of the branch flow path 12. A valve 22 for opening and closing the reduction channel 21 is provided in the middle of the reduction channel 21.

  As the coolant used in this system, water is usually used. However, it is possible to use an antifreeze obtained by mixing an antifreeze such as ethylene glycol in the water or a liquid having equivalent physical properties.

  In the above configuration, when the detection set temperature (cooling start set temperature) of the coolant circulating through the mold 10 is set to, for example, 40 ° C. and driven, the coolant in the adjustment tank 2 is passed through the circulation flow path 11 by the pump P. Circulate and cool the mold 10. At this stage, the cooling liquid in the cooling tank 1 does not flow into the adjustment tank 2. The heater 17 in the adjustment tank 2 is turned off.

When the coolant in the adjustment tank 2 recirculated from the circulation channel 11 absorbs the heat of the mold 10 and exceeds 40 ° C. (cooling start set temperature), the temperature is detected by the first temperature sensor 15 and the control valve. 13 opens, the branch flow path 12 leading to the cooling tank 1 is opened, and a part of the coolant having a high temperature in the circulation flow path 11 is returned to the cooling tank 1. The liquid amount in the cooling tank 1 is increased by the returned liquid amount, the liquid level rises, overflows from the overflow port 4 and flows into the adjustment tank 2, and the liquid temperature in the adjustment tank 2 decreases. When the coolant in the adjustment tank 2 becomes 40 ° C. or less, the first temperature sensor 15 detects and the branch flow path 12 reaching the cooling tank 1 is closed by the control valve 13. By repeating this operation, the temperature of the coolant flowing through the mold 10 can always be automatically adjusted to the set temperature (cooling start set temperature) of 40 ° C.
Further, by suppressing the inflow of the high-temperature reflux liquid from the mold 10 into the cooling tank 1 by the control valve 13, it is possible to suppress an increase in the cooling liquid temperature in the adjustment tank 2, and in the cooling tank 1. The ice can be continuously formed and melted. Further, since the second temperature sensor 18 is provided at a position away from the screw tube surface of the evaporator 8 and not in contact with the tank wall surface, as described above, the area around the temperature sensing portion of the second temperature sensor 18 maintains the water phase. During the operation, the temperature does not fall below the freezing point, and the cooling water temperature in the cooling tank 1 can be accurately detected.

It should be noted that for the continuous generation of ice in the cooling tank 1, it is important to attach the temperature sensing portion of the second temperature sensor 18 and to control the flow rate of the coolant flowing into the cooling tank 1 from the branch flow path 12. Become an element.
According to the inventor's experiment, the control valve 13 is not completely closed even when the cooling liquid in the adjustment tank 2 becomes 40 ° C. or lower. The temperature sensor 18 is installed at a position about 3 cm away from the surface of the screw tube of the evaporator 8 and is set to be turned on when the cooling water temperature is about 10 ° C. or higher, preferably 5 ° C. or higher. The generation of ice on the tube surface could be continued and the cooling water temperature inside the cooling bath 1 could be stably maintained at the set temperature.

Next, a case where the mold 10 is cooled with a coolant in a high temperature region of, for example, 85 ° C. like a polycarbonate resin will be described.
First, the power of the heater 17 is turned on, the temperature at which the heater 17 is turned on (heating start set temperature) is set to 85 ° C., and the control valve 13 of the branch flow path 12 connected to the cooling tank 1 is opened. The temperature of the coolant (cooling start set temperature) is set to 85 ° C. or higher, for example, 90 ° C.
Thereby, the coolant in the adjustment tank 2 recirculated from the circulation flow path 11 is warmed to 90 ° C. by the heater 17, and when the temperature exceeds 90 ° C., the temperature is detected by the first temperature sensor 15 and the heater 17 is Switching to OFF, the coolant is maintained at approximately 90 ° C. If the coolant exceeds the abnormally elevated by 90 ° C. to absorb heat from the mold 10 (cooling start temperature setting), the flow path is opened by the control valve 13 reaches the cooling tank 1 is opened, A part of the coolant having a high temperature in the circulation channel 11 is returned to the cooling tank 1. The liquid amount in the cooling tank 1 is increased by the returned liquid amount, the liquid level rises, overflows from the overflow port 4 and flows into the adjustment tank 2, and the liquid temperature in the adjustment tank 2 decreases. When the temperature of the cooling liquid in the adjustment tank 2 decreases, the first temperature sensor 15 detects and the branch flow path 12 reaching the cooling tank 1 is closed by the control valve 13. Thereby, it is possible to reliably prevent the temperature of the coolant passing through the mold 10 from deviating from the set temperature range.

  As described above, in the present invention, the temperature of the mold coolant is changed from a low temperature range of about 10 ° C. to a middle temperature range of about 50 ° C. to 60 ° C. by effective use of waste heat of the mold 10 and cooling by the cooling device 5. You can get up to energy saving. In addition, by using the heater 17 added to the system, the temperature of the mold coolant can be raised to a high temperature of 90 ° C., for example, and resin molding in a high temperature range such as polycarbonate resin is possible. Become. Thereby, the mold cooling temperature can be covered in a wide range from a low temperature range to a high temperature range, and various demands can be dealt with. In addition, since the heater 17 only needs to be attached in the middle of the adjusting tank 2 or the circulation flow path 11, the configuration is simple and the cost can be reduced.

  Further, in the present embodiment, the screw-type evaporator 8 of the cooling device 5 is disposed inside the cooling space 1a of the cooling tank 1 so as to cool the coolant directly, so that the evaporator 8 is hidden and the appearance image is smart. Compared with the case where the evaporator 8 is installed outside the cooling tank 1, the pipeline and the pump for circulating the coolant between the evaporator 8 and the cooling tank 1 can be omitted, and the configuration can be simplified. It becomes. Moreover, a large amount of cold energy can be stored by generating ice in the evaporator 8 in the cooling tank 1, and the thermal efficiency can be increased. Furthermore, by providing a timer function for cooling the cooling device 5 at the reserved time, ice can be generated in the middle of the night when the electricity bill is inexpensive.

  FIG. 3 is an explanatory view showing a second embodiment of a temperature control system for a molding die according to the present invention. In the second embodiment, the heater 17 is provided in the middle of the coolant circulation channel 11 from the mold 10 to the adjustment tank 2. In this case, since the heater 17 is outside the adjustment tank 2, maintenance of the heater 17 is facilitated.

(Experiment 1)
Table 1 below shows the cooling efficiency test results of the product of the present invention, the comparative product 1, the comparative product 2, and the comparative product 3.
Comparative product 1 is a commercial mold cooling device that cools the mold cooling water only with a refrigerator, comparative product 2 is a mold cooling device having the mechanism of Patent Document 1, and comparative product 3 is a freezer. This is a mold cooling apparatus that includes a machine and a heater and generates cold / hot water in a temperature range of 5 ° C. to 90 ° C. in a circulation path of only one cooling tank.
The number in the table indicates the COP simple value measured in accordance with the cooling capacity test method of JIS B 8613 “Water Chilling Unit” Appendix 1, and the COP value is obtained by the following calculation formula.
COP value = cooling capacity (kcal) ÷ power consumption (kWh)
In the test, in terms of 1 kWh = 860 kcal, the mold cooling apparatus was operated for about 1 hour, and the electric power required to generate cooling water at a predetermined set temperature was measured and calculated according to the above formula. The larger the COP value, the higher the power-to-heat conversion efficiency. From this test, as shown in Table 1 below, it can be seen that the product of the present invention is superior in conversion efficiency to any of the comparative products.

(Embodiment 2)
Next, a temperature control system according to another embodiment of the present invention will be described. In the second embodiment described here, it is possible to easily switch between an “ice generation mode” in which ice is actively generated and an “ice melting mode” in which ice is actively melted to save power. For example, by creating a large amount of ice in the “Ice Generation Mode” in the cooling tank at a time when the electricity charge is cheap, and melting the ice in the “Ice Melting Mode” at a time when the power usage is at its peak. It is possible to easily reduce the amount of power used in the time zone, so that the ice heat storage can be used more efficiently than in the first embodiment.

  FIG. 4 is an explanatory view showing a third embodiment of a temperature control system for a molding die according to the present invention. In addition, about the same component of the temperature control system shown in FIG. 1, the same code | symbol is attached | subjected and some description is abbreviate | omitted.

In this embodiment, the branch flow path 12 that branches from the middle of the flow path to the mold 10 of the coolant circulation flow path 11 and reaches the cooling tank 1 is further connected to the first cooling tank at the end side of the branch flow path 12. The flow path 31 and the second cooling tank connection flow path 32 are branched. The first cooling tank connection channel 31 is connected to an ice melting connection port 33 provided in the cooling space 1 a of the cooling tank 1. The ice melting connection port 33 is preferably provided on the upstream side of the cooling space 1a as much as possible. The second cooling tank connection channel 32 is connected to an ice generating connection port 34 provided in the cooling space 1a (or the liquid feeding space 1b) in the vicinity of the liquid feeding space 1b. In this way, the ice melting connection port 33 is provided upstream of the ice generation connection port 34.
A first control valve 35 that performs open / close control is provided in the middle of the first cooling tank connection flow path 31 after branching from the branch flow path 12. Similarly, the second cooling after branching from the branch flow path 12 is provided. A second control valve 36 that performs opening / closing control is also provided in the middle of the tank connection flow path 32.

A first temperature sensor 15 that detects the temperature of the coolant is provided in the adjustment tank 2.
The first control valve 35 and the second control valve 36 provided in the branch flow path 12 are normally closed. When the detected temperature of the coolant in the adjustment tank 2 by the first temperature sensor 15 becomes equal to or higher than a preset cooling start set temperature, the first control valve 35 or the second control valve 36 (or both) may be used. Is opened, the flow path from the branch flow path 12 to the cooling tank 1 (via the first cooling tank connection flow path 31 or the second cooling tank connection flow path 32) is opened, and a part of the cooling liquid in the circulation flow path 11 is opened. Is returned to the cooling tank 1 through the branch flow path 12. When the detected temperature of the first temperature sensor 15 is equal to or lower than the cooling start set temperature, the opened first control valve 35 or the second control valve 36 is closed so that the branch flow path 12 to the cooling tank 1 is closed. It is. The means for controlling such settings can be easily performed by a computer incorporating a control program. It can also be implemented by a combination of electronic control units.

  In the cooling space 1a of the cooling tank 1, the evaporator 8 is disposed inside the cooling tank 1, and is configured to directly cool the cooling liquid in the cooling tank 1 by heat exchange, and is maintained at a temperature at which ice can be generated. Also configured to be able to.

Furthermore, in this embodiment, it is possible to easily switch between a state in which ice is generated in the cooling tank 1 to promote ice heat storage (ice generation mode) and a state in which the accumulated ice is melted (ice melting mode). In order to make it possible, the flow path for returning the high-temperature cooling liquid from the circulation flow path 11 to the cooling tank 1 from the branch flow path 12 is branched into a plurality, and the introduction position of the cooling liquid to the cooling tank 1 can be switched. It is like that.
Specifically, the “ice generation mode” is selected by input from an input device (not shown) attached to a control means such as a computer or an electronic control unit incorporating the above-described control program, or simply manually. By the operation, the second control valve 36 is controlled to open and close to function as a control valve (the control valve 13 in FIG. 1) (the first control valve 35 is closed), and the “ice melting mode” is selected by selecting the “ice melting mode”. The first control valve 35 is controlled to open and close to function as a control valve (the second control valve 36 is closed). That is, a function as a flow path switching mechanism that switches between the first cooling tank connection flow path 31 and the second cooling tank connection flow path 32 and a function as a control valve by the first control valve 35 and the second control valve 36. Is also used.

Next, the operation in each mode will be described. In the state where the “ice generation mode” is selected, when the temperature detected by the first temperature sensor 15 of the coolant in the adjustment tank 2 is equal to or higher than the preset cooling start temperature, the second control valve 36 is The flow path from the second cooling tank connection flow path 32 to the cooling tank 1 is opened, and a part of the cooling liquid in the circulation flow path 11 is returned to the cooling tank 1 from the ice generation connection port 34. When the detected temperature is equal to or lower than the cooling start set temperature, the second control valve 36 is closed and the branch flow path 12 to the cooling tank 1 is closed.
In this case, the high-temperature cooling liquid that has entered the cooling tank 1 through the ice generating connection port 34 touches only the vicinity of the downstream side of the cooling space 1a, exchanges heat, and is sent to the liquid sending space 1b. Then, the second control valve 36 is controlled to open and close so that the cooling liquid in the liquid feeding space 1b flows into the adjustment tank 2 and the temperature of the cooling liquid in the adjustment tank 2 becomes the cooling start set temperature. At that time, a large amount of the cooling liquid existing in the cooling space 1a is hardly affected by the high-temperature cooling liquid entering from the ice generating connection port 34, and is continuously cooled by the evaporator 8 in a stagnant state. Ice is produced upon cooling to below 0 ° C. At this time, the electric power consumed by the cooling device 5 becomes latent heat of ice and is stored as cold energy.

In the state where the “ice melting mode” is selected, when the temperature detected by the first temperature sensor 15 of the coolant in the adjustment tank 2 is equal to or higher than the preset cooling start temperature, the first control valve 35 is The flow path from the first cooling tank connection flow path 31 to the cooling tank 1 is opened and a part of the cooling liquid in the circulation flow path 11 is returned to the cooling tank 1 from the ice melting connection port 33. When the detected temperature is equal to or lower than the cooling start set temperature, the first control valve 35 is closed and the branch flow path 12 to the cooling tank 1 is closed.
In this case, the high-temperature coolant that has entered the cooling tank 1 is heat-exchanged while melting the ice accumulated in the cooling space 1a (assuming that the ice is already stored in the cooling space 1a). Since it can cool using the latent heat (melting heat) when ice melts, it is not necessary to cool by the cooling device 5, and power consumption can be suppressed. Then, since the cooling liquid in the liquid feeding space 1b flows into the adjustment tank 2, the first control valve 35 is controlled to open and close so that the temperature of the cooling liquid in the adjustment tank 2 becomes the cooling start set temperature. Then, the coolant can be sent to the adjustment tank 2 while saving power until the accumulated ice melts.
Therefore, by generating ice in the “Ice Generation Mode” at a time when the electricity bill is cheap at night, and cooling while saving electricity in the “Ice Melting Mode” during peak hours of daytime power consumption, the power cost is reduced. This can reduce power consumption at the peak of power consumption.

Next, a modified example will be described. FIG. 5 is an explanatory view showing a fourth embodiment. In addition, about the same component of the temperature control system shown in FIG. 4, description is abbreviate | omitted by attaching | subjecting the same code | symbol.
In this embodiment, the branch flow path 12 that branches from the middle of the flow path to the mold 10 of the coolant circulation flow path 11 and reaches the cooling tank 1 is connected to the first cooling tank connection flow at the end side of the branch flow path 12. The path 41 and the second cooling tank connection channel 42 are branched. As in the embodiment of FIG. 4, the first cooling tank connection channel 41 is connected to an ice melting connection port 43 provided on the upstream side of the cooling space 1 a of the cooling tank 1. The second cooling tank connection channel 42 is connected to an ice generation connection port 44 provided on the downstream side of the cooling space 1a.
A control valve 13 is provided in the middle of the branch flow path 12, and branches into a first cooling tank connection flow path 41 and a second cooling tank connection flow path 42 on the downstream side of the control valve 13. A first switching valve 45 for switching the flow path is provided in the middle of the first cooling tank connection flow path 41, and a first switching valve 45 for switching the flow path also in the middle of the second cooling tank connection flow path 42. Two control valves 46 are respectively provided. That is, in the present embodiment, a first switching valve 45 and a second switching valve 46 which are flow path switching mechanisms are provided separately after the control valve 13.

  When the “ice generation mode” is selected, the second switching valve 46 is opened and the first switching valve 45 is closed. When the “ice melting mode” is selected, the first switching valve 45 is opened and the second switching valve 46 is closed.

  Next, the operation in each mode will be described. In the state in which the “ice generation mode” is selected (the second switching valve 46 is in the open state), the detection temperature of the coolant in the adjustment tank 2 detected by the first temperature sensor 15 is set to the desired cooling start set in advance. When the temperature is higher than the set temperature, the control valve 13 is opened, the flow path from the second cooling tank connection flow path 42 to the cooling tank 1 is opened, and a part of the cooling liquid in the circulation flow path 11 passes through the ice generation connection port 44. Returned to the cooling bath 1. When the detected temperature is equal to or lower than the cooling start set temperature, the control valve 13 is closed and the branch flow path 12 to the cooling tank 1 is closed.

In a state where the “ice melting mode” is selected (the first switching valve 45 is in an open state), the detected temperature of the coolant in the adjustment tank 2 by the first temperature sensor 15 is a preset cooling start set temperature. When the above is reached, the control valve 13 is opened and the flow path from the first cooling tank connection flow path 41 to the cooling tank 1 is opened, and a part of the coolant in the circulation flow path 11 is cooled from the ice melting connection port 43 to the cooling tank. Returned to 1. When the detected temperature is equal to or lower than the cooling start set temperature, the control valve 13 is closed and the branch flow path 12 to the cooling tank 1 is closed.
In this way, the same control can be realized even if the control valve 13 and the flow path switching mechanism (the first switching valve 45 and the second switching valve 46) are provided separately.

  In the embodiment described above, the flow path returning to the cooling tank 1 is set to one of the first cooling tank connection flow path 41 and the second cooling tank connection flow path 42 by the “ice generation mode” and the “ice melting mode”. However, instead of this, the first cooling tank connection flow path 41 and the second cooling tank connection flow path 42 are alternately switched to open and close, and the high-temperature coolant returned to the two flow paths The ratio may be changed. For example, in the “ice generation mode”, the flow rate ratio between the first cooling tank connection channel 41 and the second cooling tank connection channel 42 may be set to 9: 1, and in the “ice melting mode”, 1: 9 may be set. .

  Moreover, in each said embodiment, although the branch flow path branched into two cooling tank connection flow paths, it branches into three or more, for example, connects the three places of the upstream, downstream, and center of the cooling space 1a. A mouth may be provided. Thereby, it becomes possible to easily adjust the amount of ice generated by ice heat storage.

(Experiment 2)
Next, the verification experiment of the ice heat storage in the temperature control system of Embodiment 2 was conducted. That is, ice generation (ice heat storage) is carried out concurrently while circulating cold temperature controlled water set to a predetermined temperature to the mold, and then the cooling device 5 is stopped and the mold temperature is adjusted using ice heat storage. It was adjusted. Experiments and experimental results at that time will be described.

FIG. 6 is an explanatory view showing a fifth embodiment of the mold temperature control system according to the present invention used in Experiment 2. In FIG. The same functional parts as those shown in FIGS. 4 and 5 are denoted by the same reference numerals, and a part of the description is omitted.
In 5th Example, the control valve 13 is provided in the middle of the branch flow path 12 to the cooling tank 1, and the terminal side of the branch flow path 12 is the 1st cooling tank connection flow path 51, the 2nd cooling tank connection flow. The passage 52, the third cooling tank connection flow path 53, and the fourth cooling tank connection flow path 54 are branched into four flow paths, each of which includes a first switching valve 55, a second switching valve 56, a third switching valve 57, and a first switching valve. A four-switching valve 58 is provided.
The first cooling tank connection flow path 51 is connected to an ice generation connection port 51 a provided on the downstream side of the cooling space 1 a of the cooling tank 1. The fourth cooling tank connection channel 54 is connected to an ice melting connection port 54 a provided on the upstream side in the cooling space 1 a of the cooling tank 1. Furthermore, the second cooling bath connection channel 52 and the third cooling tank connection channel 53, the intermediate connection mouth 52a provided near the center of the cooling space 1a, is connected to 53a. Depending on whether the intermediate connection ports 52a and 53a are used during ice generation or during ice melting, the intermediate connection ports 52a and 53a are used as both ice generation connection ports and ice melting connection ports.

  As described above, the four switching valves of the first switching valve 55, the second switching valve 56, the third switching valve 57, and the fourth switching valve 58 are provided so that the flow rate in the cooling space 1a of the cooling tank 1 can be adjusted. I made it. In addition, although each connection port 51a-54a can be attached to the arbitrary parts of the side surface or bottom face of the cooling tank 1, it is made to attach to a side surface from the ease of a maintenance and attachment work.

In this experiment 2, ice heat storage is performed in the cooling tank 1 while supplying a predetermined cold temperature controlled water to the mold 10 according to the set temperature of the adjustment tank 2, and then the ice generated in the cooling tank 1 is melted. By taking out the cold heat, the preferred conditions for realizing mold temperature adjustment with predetermined cold temperature adjustment water while the cooling device 5 was stopped were confirmed.
In the ice generation and ice melting step, the selection condition of the connection port for returning the cooling water warmed to the cooling bath 1 is important. Therefore, in this experiment 2, a suitable method of use as a practical mold temperature control system by adjusting the switching valve was examined.

In this experiment 2, defines a coolant temperature to be sent at a set temperature of the first temperature sensor 15 installed in the control vessel 2 into the mold 10, the second temperature sensor 18 installed in the cooling tank 1 The refrigeration cycle of the cooling device 5 was operated.
In "Ice generating operation" for ice-thermal storage while driving as a normal mold temperature adjusting system, since the branch flow path 12, the first switching valve 5 5 to open, the other switching valve 5 6-5 8 Closed.
And melting the ice taken out cold in "thawing operation", and the switching valve 5 6-5 8 to open the reverse was the switching valve 5 5 closed. In some comparative experimental examples (Experiment No. 3), the switching valves 5 5 and 5 8 were opened.

In addition, a flow meter was installed in the mold channel (coolant circulation channel 11 ) for grasping the operation status and monitoring each part of the system. Moreover, the liquid temperature of the cooling liquid inlet to the metal mold | die 10 and the liquid return port from the metal mold | die to the adjustment tank 2 side was measured with the thermocouple. By monitoring the liquid temperature at the liquid inlet and return port to the mold 10 described above, it is possible to determine whether the mold temperature adjustment is realized under a predetermined condition or is not controllable. there were. Table 2 below collectively shows the monitoring results in Experiment 2.

In Table 2, Experiment No. Under condition 2, ice storage was realized under normal operation for over 1 hour (67 minutes), and the mold temperature was adjusted normally even if the cooling device was stopped for 51 minutes. Thereby, it was confirmed that the ice heat storage in the mold temperature control system of this example is effective.
Experiment No. Even under the condition 1, ice heat storage could be realized under a normal operation of 180 minutes, and the mold temperature was adjusted normally even if the cooling device was stopped for 49 minutes.

On the other hand, Experiment No. as a comparative experiment. In 3, the cold energy stored in ice could not be taken out sufficiently. No. Was not melted all ice 3, thawing process, but determines that the cause (it has a first switching valve 5 5 opens when de-ice) flow path selection of the cooling liquid is unsuitable .

As described above, the representative embodiments of the present invention have been described. However, the present invention is not necessarily limited to the above-described embodiment structures, and can be appropriately modified within the scope of achieving the object and without departing from the scope of the claims. It is possible to change. The cooling device 5 shown in the explanatory diagram of each embodiment shows the connection with the external chilled water tower 23 , but instead of the chiller using the external chilled water tower, a chiller having an air-cooled heat exchange unit is arranged. May be. As the cooler, not only a cold water tower but also an air-cooled heat exchange unit is suitable.

Moreover, in each Example, although the liquid flow in this space is controlled by selection of the flow path connected to the cooling space 1a in the cooling tank 1, as a means of liquid flow control, for example, the bottom face of the adjustment tank 2 It is also effective to make a small hole and let it pass through the cooling tank 1 . In particular, it is convenient to allow both tanks to have a communication structure during water supply and drainage when performing maintenance of cooling water for the daily mold temperature control system.

Further, the adjustment tank 2 may be configured such that the partition wall 3 with the cooling tank 1 is divided into a partition plate and a bottom plate, and the position of the partition plate can be moved and adjusted with respect to the bottom plate. This makes it possible to arbitrarily change the volume ratio between the adjustment tank 2 and the cooling tank 1 and the area of the partition wall 3 adjacent to both tanks.

  INDUSTRIAL APPLICABILITY The present invention can be applied as a temperature adjustment system for a molding die in a plastic injection molding machine, and can be used as a temperature adjusting water for air conditioning, for example, as a device for generating temperature-controlled water for air conditioning.

DESCRIPTION OF SYMBOLS 1 Cooling tank 2 Adjustment tank 3 Bulkhead 4 Overflow port 5 Cooling device 8 Evaporator 10 Mold 11 Coolant circulation flow path 12 Branch flow path 13 Control valve 14 Bypass flow path 15 Temperature sensor 17 Heater 18 2nd temperature sensor 31 1st Cooling tank connection flow path 32 Second cooling tank connection flow path 33 Ice melting connection port 34 Ice generation connection port 35 First control valve 36 Second control valve P Pump

Claims (5)

A cooling device including an evaporator capable of cooling the cooling liquid and generating ice by cooling the cooling liquid ;
A cooling tank that is provided so that an upstream cooling space and a downstream liquid feeding space communicate with each other, the evaporator of the cooling device is disposed in the cooling space, and stores the cooling liquid cooled by the evaporator ; ,
An adjustment tank for storing the coolant fed from the liquid feeding space of the cooling tank;
A coolant circulation passage returning from the adjustment tank to the adjustment tank via the mold,
A branch channel branched from the middle of the coolant circulation channel to reach the cooling space of the cooling tank;
A control valve provided in the middle of the branch flow path;
A first temperature sensor for detecting a temperature of the coolant in the adjustment tank or the coolant circulation path;
The adjusting tank or provided in the coolant circulation flow path, a heater provided with a ON / OFF operation control function by comparing the detected temperature with a preset heating start set temperature of the first temperature sensor And consist of
The heater is turned ON when the detected temperature of the first temperature sensor falls below the heating start setting temperature becomes equal to or larger than the heating start temperature setting is formed to OFF operation, the temperature detected by the first temperature sensor is becomes equal to or larger than a preset cooling start set temperature, is formed such that a portion of the high temperature of the coolant of the coolant circulation flow path wherein the control valve is opened is returned to the cooling space of the cooling bath, the cooling is formed from the said liquid feed space of only cooling the liquid volume returned to the space the cooling bath tank as low-temperature cooling liquid flows into the adjustment tank,
The cooling tank and the adjustment tank are formed in an integral structure divided by a partition wall,
A second temperature sensor for detecting the temperature of the cooling liquid in the cooling tank is provided in the vicinity of the boundary between the cooling space and the liquid feeding space of the cooling tank, and the temperature detected by the second temperature sensor A temperature control system for a molding die formed so as to control a cooling device to control the temperature of the cooling liquid in the cooling tank and to control ice generation in the cooling space . Before Stories second temperature sensor away 1cm~10cm from threaded tube surface of the evaporator is arranged at a position not in contact with the vessel wall, mold temperature control system according to claim 1. Terminal portion of said branch channel is at least two to be branched plurality of cooling tank connection flow path is formed, one of the cooling bath connecting channel is connected to the ice melting connection port provided in the cooling space One of the cooling tank connection flow paths is connected to an ice generation connection port provided in the liquid feeding space or a cooling space near the liquid feeding space,
3. The molding metal according to claim 1, wherein the branch channel is provided with a channel switching mechanism that switches a cooling tank connection channel that sends a high-temperature coolant from the coolant circulation channel. Mold temperature control system. The said control valve is each provided on the flow path after the said branch flow path has branched to each cooling tank connection flow path, The said control valve serves as the function of the said flow-path switching mechanism, The metal mold | die of Claim 3 Mold temperature control system. The control valve is provided on the upstream side of the branch flow path branching to each cooling tank connection flow path, and has a flow path switching mechanism that switches the flow path on each cooling tank connection flow path separately from the control valve. mold temperature adjustment system according to claim 3 provided.

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