KR100558400B1 - Temperature control system of mold and method thereof - Google Patents

Abstract

The present invention relates to a temperature control system of a mold and a method thereof, wherein, in a temperature control system of a mold for supplying cold water and hot water to a mold and maintaining the set temperature, a cold water inlet line having an inlet check valve is provided with a pressure switch. It is connected to the water tank, the supply line of the make-up water tank is connected to the pump connected to the other supply line of the heater tank, the outlet line of the pump is connected to the mold by the temperature sensor is installed, while the return line of the mold Is connected to the heater tank and the drain line having a drain solenoid valve is connected to the branch, and the return line and the drain line of the mold is connected to the replenishment tank while the pressure discharge line having a pressure discharge valve is connected to the branch. do.

According to the present invention, high temperature molding and productivity can be improved by accurate temperature control, and can also have a freeze protection function during the mold replacement or winter time, and can be stabilized by the automatic pressure discharge operation.

Mold, Temperature Control, Pressure Discharge, Direct Cooling, Residual Water Removal, Safety Device

Description

Temperature control system of mold and method thereof

1 is a schematic diagram of a mold temperature control system according to an embodiment of the present invention;

2 is a circuit block diagram of a mold temperature control system according to an embodiment of the present invention;

3 is an operation flowchart of a mold temperature control system according to the present invention.

   Explanation of symbols on the main parts of the drawings

3: inlet line 7: replenishment tank

9: pressure switch 15: heater tank

17 pump 19 outlet line

21: mold 25: temperature sensor

27: return line 29: drainage solenoid valve

31: drain line 33: pressure discharge valve

35: pressure discharge line 37: drain solenoid valve

102: power switch 104: mode key

110: control unit 152: pressure discharge lamp

154: cold water lamp

The present invention relates to a mold for molding a synthetic resin injection molding, and more particularly, to a temperature control system and a method of a mold having various safety devices for preventing failure while improving the quality of the injection molded article with more accurate temperature control during the injection molding operation. It is about.

In general, molds can be divided into injection molds for producing plastic (synthetic resin) products, press molds for making products using iron plates, and die casting molds for melting metals to make them together with plastics.

Among them, the injection molding mold of synthetic resin fills the material melted at a high temperature between the molds using high pressure to produce a product according to the internal shape of the mold. At this time, a defect is produced by using a high temperature material. It is designed to precisely control the temperature of the mold to improve the quality of the product to be molded. This allows injection molding without controlling the temperature of the mold. However, the precise temperature control of the mold provides the appearance, electrical characteristics, Since it significantly affects shrinkage or dimensions, the mold temperature is appropriately adjusted according to the injection molded product.

Conventionally, in order to control the mold temperature, the hole for installing the temperature sensor in the mold must be processed, and the hole processing of the mold is brought about a considerable difficulty, which is heat-treated in the already manufactured mold, while the discharge processing When the hole is processed, a lot of processing cost is consumed per mold, and even if the position of the hole is installed correctly, the temperature sensor is located in the correct position due to the complicated structure (for example, the pin, the coolant passage, etc.) in the mold. There was a difficulty in mounting it.

In addition, in the system for controlling the temperature management of the mold by the fluid, there is a problem that the temperature deviation and the electrical energy loss are increased even when the sensor is mounted in the mold.

In order to solve this problem, a system for controlling the temperature of the mold during injection molding is proposed in the patent application No. 2000-21443, which is applied by the present applicant. Although it has the advantage of having a considerable effect on the removal of residual water, etc., the pipe layout (lay-out) is increased due to the number of valves of the pipe has a problem that the manufacturing cost increases.

Therefore, the present invention has been made to solve the conventional problems as described above, the object of the present invention is to precisely control the temperature of the mold during the injection molding of the synthetic resin to improve the appearance of the product while improving the quality of the mold during the winter exchange The present invention provides a temperature control system and a method of a mold having a freeze protection function.

It is another object of the present invention to provide a temperature control system and a method of a mold having a temperature control function of a mold and performing an automatic pressure discharge operation to stabilize the system while being convenient to use.

It is still another object of the present invention to provide a temperature control system and a method of a mold for improving cooling efficiency by a direct cooling method of maintaining a mold temperature at a set temperature.                         

In order to achieve the above object, a temperature control system of a mold according to the present invention is a temperature control system of a mold for supplying cold water and hot water to a mold to maintain a set temperature, wherein a cold water inlet line having an inlet check valve is provided with a pressure switch. It is connected to the replenishment tank equipped, the supply line of the replenishment tank is connected to the pump is connected to the other supply line of the heater tank, the outlet line of the pump is installed on the mold while the temperature sensor is connected to the mold The return line is connected to the heater tank and the drain line having a drain solenoid valve is connected to the branch, and the return line and the drain line of the mold are connected to the make-up water tank while the pressure discharge line having a pressure discharge valve is connected to the branch. It features.

And, the temperature control method of the mold according to the present invention, in the temperature control method of the mold to supply the cold water and hot water to the mold to maintain the set temperature, when the power switch is operated by operating the drainage solenoid valve for cold water inlet line Introducing cold water into the replenishment tank through; Determining whether or not the low water level by detecting the pressure of the cold water flowing into the make-up water tank in the pressure switch; Supplying cold water to a mold through a supply line and a pump of the make-up water tank by operating a pump if it is determined that the water level is not low in the step; Sensing a fluid temperature of the cold water supplied to the mold and operating a heater when the temperature is lower than a predetermined temperature to heat the cold water introduced into the heater tank through a return line of the mold; Supplying hot water from the heater tank to a mold through a supply line and a pump of the heater tank to raise the mold temperature to a set temperature; Detecting the mold temperature rising according to the operation of the heater and if the temperature is above the set temperature, by operating the drainage solenoid valve for a predetermined time while supplying cold water to the mold by lowering the mold temperature to the set temperature ; And detecting a mold temperature which is lowered according to the operation of the drain solenoid valve and comparing the temperature with a set temperature, thereby controlling the operation of the heater and the drain solenoid valve according to the comparison result to maintain the mold temperature at the set temperature. Characterized in that made.

In addition, the present invention is characterized in that when the pressure of the cold water flowing into the replenishment water tank is determined to be a low water level, and stops the operation of all the valves while alarming the low water level, the initial operation of the power switch of the drain solenoid valve At the same time as operating the pressure discharge valve for a predetermined time characterized in that it further comprises the step of automatically discharging pressure.

In addition, the present invention comprises the steps of sensing the pressure rises as the mold temperature rises during the operation of the heater in the pressure switch to determine whether the normal pressure range; And operating the pressure discharge valve for a predetermined time when the pressure is equal to or greater than the normal pressure range, and automatically discharging the pressure during operation of the system.

In addition, the present invention comprises the steps of determining whether the mode key is selected when the power switch is off; And operating the drain solenoid valve for a predetermined time when the mode key is selected, and discharging the residual water through the drain line and the drain line.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is an overall system diagram of a mold temperature control system according to an embodiment of the present invention, Figure 2 is a circuit block diagram of a mold temperature control system according to an embodiment of the present invention.

Referring to FIG. 1, the compressed air line 5 is connected to the cold water inlet line 3 having the inlet check valve 1, and is connected to the make-up water tank 7 having the pressure switch 9. The supply line 7a of the tank 7 is connected in parallel with the other supply line 15a of the heater tank 15 to the pump 17, and the outlet line 19 of the pump 17 is a mold 21. On the other hand, a semi-mould (23) equipped with a temperature sensor (25) is installed in the outlet line (19) of the pump (17).

On the other hand, the pressure switch 9 installed in the refill water tank 7 is integrally formed with a low pressure switch 11 for detecting the water level of the refill water tank 7 and a high pressure switch 13 for detecting the pressure. .

The return line 27 of the mold 21 is connected to the heater tank 15 having the heater 16 and the drain line 31 having the drain solenoid valve 29 is branched, and the mold 21 Residual / pressure squeeze line 35 (hereinafter referred to as pressure relief valve) having a solenoid valve (33; hereinafter referred to as a pressure relief valve) for residual water removal and discharge of pressure in the system in the return line 27 and the drain line 31 of Is connected to the make-up water tank (7), and the drain line (39) having a drain solenoid valve (37) is connected to the heater tank (15).

A circuit diagram for controlling the system diagram of the mold temperature control system according to the present invention configured as described above will be described with reference to FIG.

As shown in FIG. 2, the temperature control system of the mold according to the present invention includes a signal input unit 100 including a power switch 102 and a mode key 104; A pressure switch 9 composed of a low pressure switch 11 and a high pressure switch 13; A temperature sensor 25 for sensing a fluid temperature passing through the outlet line 19 of the pump 17; A controller (110) for receiving data from the signal input unit (100), the pressure switch (9) and the temperature sensor (25) to control the overall operation of the system; A pump driver 120 operated according to a control signal from the controller 110; A heater driver 130 operated according to a control signal from the controller 110; A valve driver 140 driving and controlling the inlet check valve (1), the drain solenoid valve (29), the pressure discharge valve (33), and the drain solenoid valve (37) according to a control signal from the controller (110); A display unit 150 for driving and controlling the pressure discharge lamp 152 and the cold water lamp 154 which display the operating states of the valves 1, 29, 33 and 37 according to the control signal from the controller 110; And it is configured to include an alarm generating unit 160 for generating a low water level alarm.

Hereinafter, the temperature control adjustment operation of the mold using the temperature control system of the mold configured as described above is as follows.

3 is an operation flowchart of a mold temperature control system according to the present invention, in which S denotes a step.

First, when the main power switch 102 is turned on (S1), power is supplied to the system so that the drainage solenoid valve 29 is operated (opened), and at this time, the time for opening the drainage solenoid valve 29 is controlled. Set to dt mode (open function of power switch solenoid valve for initial drain) and select from 0 to 60 seconds. If 0 is selected, it is not opened and the cold water lamp 154 blinks while it is open. The initial setting value is set to 10 seconds (S2).

Meanwhile, in the embodiment of the present invention, the operating time of the solenoid valve 29 for drainage in the dt mode is set to 60 seconds or less, but the present invention is not limited thereto and may be set to 60 seconds or more according to the structure and design specifications of the system. Of course.

At the beginning of the operation of the power switch 102, at the same time as the operation of the drain solenoid valve 29, the pressure relief valve 33 is also operated (opened) in the mold temperature control system of the present invention, wherein the pressure relief valve 33 Open time is set in the control unit 110 in the rt mode (power switch operation initial pressure release valve opening function) and select from 0 to 60 seconds. If 0 is selected, it is not opened, and yellow pressure discharge lamp 152 blinks while it is open. The initial setting value is set to 7 seconds (S3).

Meanwhile, in the embodiment of the present invention, the operating time of the pressure relief valve 33 is set within 60 seconds in the rt mode, but the present invention is not limited thereto and may be set to 60 seconds or more according to the structure and design specifications of the system. Of course.

On the other hand, the control unit 110 is designed to set the rp mode for controlling the start and stop of the pump 17 during the opening time of the pressure discharge valve 33 in the initial operation of the power switch 102.

When the drain solenoid valve 29 and the pressure discharge valve 33 are operated (opened), the cold water obtained through the inlet line 3 flows into the supplemental water tank 7 through the inlet check valve 1. The pressure of the cold water flowing into the make-up water tank 7 is detected by the pressure switch 9 (low pressure switch) installed in the make-up water tank 7 and output to the control unit 110. (S4)

Therefore, the controller 110 compares whether the water inlet pressure detected by the pressure switch 9 is 1 kg / cm 2 or less, and determines that the water level is 1 kg / cm 2 or less, and determines the (YES) alarm generation unit 160. While the low water level is alerted through the operation of the drain solenoid valve 29 and the pressure discharge valve 33 to stop (close) (S41).

On the other hand, if the water inlet pressure sensed by the pressure switch 9 is 1kg / ㎠ or more, it is determined that the water level is not low, the pump driving unit (NO) during operation of the drain solenoid valve 29 and the pressure discharge valve 33 ( The pump 17 is operated by controlling the control to 120. (S5)

When the pump 17 is operated according to the opening set time of the drain solenoid valve 29, the cold water introduced into the make-up water tank 7 passes through the supply line 7a of the make-up water tank 7 and the pump 17 ) And flows to the outlet line 19 of the pump 17.

Therefore, the fluid flow of cold water is obtained from the inlet line 3 → the replenishment tank 7 → the supply line 7a → the pump 17 → the outlet line 19 → the mold 21 → the return line 27 → the drain line. At the same time as the cold water is supplied to the mold 21, the pressure relief valve 33 performs the automatic pressure releasing operation at the beginning of the operation of the power switch 102.

Here, the water check valve 1, the drain solenoid valve 29 and the pressure discharge valve 33 are operated (opened), and the drain solenoid valve 37 is stopped (closed).

As described above, when the cold water is supplied to the mold 21, the cold water fluid passing through the outlet line 19 in the temperature sensor 25 of the semi-mould 23 installed in the outlet line 19 of the pump 17 The temperature is detected and output to the controller 110.

Accordingly, the controller 110 compares whether the cold water fluid temperature sensed by the temperature sensor 25 is less than or equal to the set temperature (the temperature range set by the user can be set in units of 1 ° C. from 0 to 254 ° C.). If (S6) is below the set temperature (YES), the heater driver 130 is controlled to start the heater 16. (S7)

When the heater 16 is operated, the cold water supplied to the mold 21 flows into the heater tank 15 through the return line 27 of the mold 21 and is heated to heat the hot water of the heater tank 15. In order to supply the mold 21 to the heater tank 15 → supply line 15a → pump 17 → outlet line 19 → mold 21 → return line 27 → hot water along the heater tank 15 Is supplied to raise the mold 21 temperature to the set temperature.

Here, the drain solenoid valve 29, the drain solenoid valve 37, and the pressure discharge valve 33 are all stopped (closed).

When the heater 21 is operated, the pressure is also increased as the temperature of the mold 21 rises. In the normal pressure range (2 kg / cm 2 to 6 kg / cm 2) (YES), the pressure is normally operated. ㎏ / ㎠ or more) (N0) in accordance with the control signal of the control unit 110, the pressure relief valve 33 (residual solenoid valve) is operated to automatically extract the pressure (air) to the normal pressure range (2㎏ / ㎠ 6 kg / cm 2) (S8)

During operation of the system, the application range of the pressure relief valve 33 is 0.01 to 2.00 seconds, the initial setting value is 0.20 seconds, and the opening time of the pressure relief valve 33 is determined by the controller 110 in accordance with the pressure rise. It is designed to be adjustable and can be set to 2.00 seconds or more according to the structure and design specification of the system. (S9)

When the temperature of the mold 21 increases as the heater 16 operates, the temperature of the mold 21 of the semi-mould 23 installed in the outlet line 19 of the pump 17 passes through the outlet line 19. The fluid temperature is detected and output to the controller 110.

Accordingly, the controller 110 compares whether the fluid temperature sensed by the temperature sensor 25 is equal to or greater than the set temperature (S10) and when the temperature is equal to or greater than the set temperature (YES), the heater driver 130 is controlled to control the heater 16. In order to stop the operation and lower the mold 21 temperature to a predetermined set temperature, the drain solenoid valve 29 is operated (opened) for 0.2 seconds. (S11, S12)

As the drain solenoid valve 29 is operated. Cold water is obtained through the inlet line (3) is introduced into the replenishment tank (7), the cold water introduced into the replenishment tank (7) is directly supplied to the mold 21 via the supply line and the pump (17) By the direct cooling method, it is possible to quickly lower the mold 21 temperature to the set temperature.

However, if the temperature does not decrease for 30 seconds after the cold water is introduced, the drain solenoid valve 29 is restarted (opened) for 0.2 seconds to lower the mold 21 temperature to the set temperature.

While controlling the heater 16 and the drain solenoid valve 29 to maintain the mold 21 temperature at a predetermined temperature, the pressure discharge valve 33 is operated at a predetermined time (application range: 0 to 60 minutes). For example, it is operated for 0.20 seconds (application range: 0.01 to 2.00 seconds) to allow automatic pressure (air) discharge operation during system operation.

On the other hand, in the embodiment of the present invention, but the operating time of the pressure relief valve 33 is set within 2.00 seconds every predetermined time, the present invention is not limited to this can be set to 2.00 seconds or more according to the structure and design specifications of the system Of course.

When the temperature of the mold 21 decreases to the cold water operating temperature deviation (0.0 to 5 ° C.) in accordance with the stop of the heater 16 and the operation (opening) of the solenoid valve 29 for drainage, the heater 16 is restarted. Since the hot water of the heater tank 15 is supplied to the mold 21, the temperature of the mold 21 rises again.

By repeating the above operations (temperature rise, temperature maintenance, temperature drop), it is possible to ensure high-quality molding and productivity improvement by precise temperature control in which heat exchange of the mold 21 proceeds.

In addition, the residual water removal to remove the cold water and hot water fluid for winter freeze protection or system maintenance and inspection is performed by using the mode key 104 as the residual water discharge key when the power is turned off. When the residual water is operated, the solenoid valve 29 for drainage is opened and the solenoid valve 29 for drainage is closed when stopped.

When the power switch 102 is turned off, the mode key 104 is toggled so that the drain solenoid valve 29 is operated (opened). At this time, the controller 110 controls the time at which the drain solenoid valve 29 is opened. Set to mode (residue removal time) and select from 0 to 120 seconds. If you select 0, it does not open, and the initial setting value is set to 30 seconds (S21, S22).

Meanwhile, in the embodiment of the present invention, the operating time of the solenoid valve 29 for drainage in the jt mode is set to 120 seconds or less, but the present invention is not limited thereto and may be set to 120 seconds or more according to the structure and design specifications of the system. Of course.

According to the operation of the drain solenoid valve 29, the compressed air line (5) → supplemental water tank (7) → supply lines (7a, 15a) → heater tank (15) → drain line (39); Compressed air line (5) → make-up water tank (7) → supply line (7a) → pump (17) → outlet line (19) → mold (21) → return line (27) → drainage along the drain line (31) It is supposed to discharge.

In this case, when the mold 21 is cooled during the winter operation, when cold water of low temperature is introduced into the replenishment water tank 7 and immediately flows into the mold 21, a sudden cooling action is generated and becomes uncontrollable.

Therefore, in the present invention, when the temperature of the mold 21 rises above the set value, the solenoid valve 29 for drainage is operated (opened) so that the cold water is supplied to the replenishment water tank 7, and the cold water is supplied to the pump 17. Cold water and hot water are simultaneously sucked and discharged through the supply lines with suction force to cool the mold 21. That is, since the cold water and the hot water are simultaneously sucked, mixed and discharged, it is possible to prevent the temperature of the mold 21 from dropping rapidly even when the temperature of the cooling water is low in winter.

In addition, the temperature control system of the mold according to the present invention reveals that the fluid can be applied to any fluid having good preheating and cooling effects as well as water.

What has been described above is just one embodiment for implementing the temperature control system and method of the mold according to the present invention, the present invention is not limited to the above-described embodiment, the technical spirit of the present invention Of course, various modifications are possible by those skilled in the art.

As described above, according to the temperature control system and method of the mold according to the present invention, by precisely controlling the temperature of the mold during the injection molding of the synthetic resin to improve the appearance quality of the product while improving the quality of the mold during freezing or winter exchange The effect is that it can also serve as a prevention function.

In addition, the present invention is easy to use and stabilize the system by performing the automatic pressure discharge operation while having a temperature control function of the mold, it is possible to increase the cooling efficiency by the direct cooling method to maintain the temperature of the mold at the set temperature It works.

Claims (6)

In the temperature control system of the mold to supply cold water and hot water to the mold to maintain the set temperature, A cold water inlet line with an inlet check valve is connected to a make-up tank with a pressure switch, and the supply line of the make-up tank is connected to another pump line of the heater tank and connected to the pump, and a temperature sensor at the outlet line of the pump. Is installed and connected to the mold, while the return line of the mold is connected to a heater tank, and a drain line having a drain solenoid valve is branched, and a pressure discharge line having a pressure discharge valve is provided at the return line and the drain line of the mold. The temperature control system of the mold, characterized in that the basin is connected to the make-up tank. In the temperature control method of the mold for supplying cold water and hot water to the mold to maintain the set temperature, Operating a drain solenoid valve when the power switch is operated to introduce cold water into the supplemental water tank through a cold water inlet line; Determining whether or not the low water level by detecting the pressure of the cold water flowing into the make-up water tank in the pressure switch; Supplying cold water to a mold through a supply line and a pump of the make-up water tank by operating a pump if it is determined that the water level is not low in the step; Sensing a fluid temperature of the cold water supplied to the mold and operating a heater when the temperature is lower than a predetermined temperature to heat the cold water introduced into the heater tank through a return line of the mold; Supplying hot water from the heater tank to a mold through a supply line and a pump of the heater tank to raise the mold temperature to a set temperature; Detecting the mold temperature rising according to the operation of the heater and if the temperature is above the set temperature, by operating the drainage solenoid valve for a predetermined time while supplying cold water to the mold by lowering the mold temperature to the set temperature ; And Detecting the mold temperature lowered according to the operation of the drain solenoid valve and comparing it with the set temperature, and controlling the operation of the heater and the drain solenoid valve according to the comparison result to maintain the mold temperature at the set temperature; Temperature control method of the mold, characterized in that made. The method of claim 2, If the pressure of the cold water flowing into the make-up water tank is determined to be a low water level temperature control method of the mold, characterized in that to stop the operation of all the valves while alarming the low water level. The method of claim 2, And automatically discharging the pressure by operating the pressure discharge valve for a predetermined time simultaneously with the operation of the drain solenoid valve in the initial operation of the power switch. The method of claim 2, Determining whether the pressure rises as the mold temperature increases during operation of the heater by a pressure switch to determine whether it is in a normal pressure range; And The step of controlling the temperature of the mold, characterized in that further comprising the step of operating the pressure discharge valve for a predetermined time when the step is above the normal pressure range to automatically discharge the pressure during operation of the system. The method of claim 2, Determining whether a mode key is selected when the power switch is turned off; And And operating the drainage solenoid valve for a predetermined time when the mode key is selected to discharge residual water through the drainage line and the drain line.

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