JP2009045814A - Method of temperature control of molding mold and temperature controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of temperature control of a molding mold which has a rapid heating and cooling control system of a simple construction, needs a limited installation space and is inexpensive in cost, highly productive and stable. <P>SOLUTION: The method comprises rapidly elevating the temperature of the mold 11 before a plasticized resin is injected in the mold cavity 12 and cooling the mold to a solidifying temperature or below after the injection is made. Steam is used for the heating medium at the start of heating. When the mold temperature reaches a predetermined temperature or a predetermined time elapses after the start of heating, the heating medium is switched to high temperature water having a set temperature for the mold 11 in molding or higher. When the mold temperature reaches the set temperature, the feed of the high temperature water is stopped and the high temperature water is replaced with cooling water, which cools the resin to the solidifying temperature or below. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to temperature control of a mold used for an injection molding machine or the like, and in particular, a temperature control method for a heating medium circuit capable of rapid heating and cooling, and a mold capable of using this temperature control method. The present invention relates to a temperature control device.

Mold in a conventional example described in Patent Document 1 includes a steam supply device, and a hot water supply device, a injection mold and a cooling water supply device, to supply water vapor to the first mold Preheating is then performed, the mold is filled with high-temperature water, the mold is heated to a set temperature, and the molten resin is injected and filled into the mold cavity. The heat of the resin filled with injection is transferred to the high-temperature water in the mold, the mold and resin are cooled by the heat of evaporation when the high-temperature water boils, and maintains a temperature commensurate with the pressure set in the pressure control valve, After a certain time, the heating medium in the mold is switched to cooling water and cooled below the solidification temperature of the resin material, and the temperature control cycle ends.

Further, the conventional example shown in Patent Document 2, optionally the hot water set temperature of the water vapor and are two set to a constant temperature by adjusting the temperature of the mold is switched by the control valve, the mold A first temperature stage for maintaining the temperature below the glass transition temperature of the molded resin material, a second temperature stage for increasing the temperature to near the flow stop temperature of the resin material, and again lowering and holding the temperature near the glass transition temperature Forming a molded product such as a high-precision resin lens without sink by passing the third temperature stage and the fourth temperature stage that cools and holds the temperature near the temperature of the first temperature stage. There are a mold temperature control device and a mold temperature control method for the purpose.
JP 62-101365 A (FIG. 1) JP-A-4-345808 (FIGS. 1 and 2)

  In the conventional example of Patent Document 1, the medium is switched from steam to pressurized hot water (high temperature water) having a saturation pressure equal to a predetermined mold temperature when the mold is heated, and the mold is filled. When the molten resin material is injected and filled, the heat from the molten resin material is transferred from the mold to the hot water, and when the hot water saturation temperature is exceeded, the hot water evaporates, and the mold temperature is cooled by the heat of evaporation. The Thus, the adjustment of the mold temperature with saturated hot water is slow, and there is a problem that the time required for the molding process becomes redundant.

  Similarly, in the conventional example of Patent Document 2, since the temperature of hot water when injecting and filling the resin material is set to match a predetermined mold temperature, the adjustment of the mold temperature becomes slow, The molding process time becomes redundant. In both of the above-mentioned conventional examples, steam is supplied from the boiler of the external facility, so a boiler facility is necessary.

  The present invention provides a mold temperature control method having a simple structure of a rapid heating / cooling control system, a small installation space, low cost, high productivity, and high stability in an injection molding apparatus. An object is to provide an apparatus.

With respect to the above problems, the present invention aims to solve the problems by the following means.
(1) The temperature control method of the molding die capable of rapid heating and cooling of the first means rapidly increases the temperature of the mold before injection molding the plasticizing resin into the mold cavity, and after injection, a method of cooling to below the solidification temperature, heating at the start using the water vapor heating medium, the molding at a mold temperature has reached a predetermined temperature, or the heating medium from the start of heating after a predetermined period of time After switching to hot water above the set temperature of the mold and raising the mold temperature to the set temperature, stop supplying hot water and switch to cooling water to cool below the resin solidification temperature To do.

(2) temperature control method of a molding die of the second means, in the mold temperature control method of the above (1), switching from the heating start of water vapor into the hot water, the pre-Me water Measure and calculate the temperature rise condition of the mold from the start of heating with steam to calculate the temperature rise characteristics of the mold, and at the same time, raise the mold with high-temperature water that is higher than the set temperature of the mold required for molding Calculate the temperature rise characteristics by actually measuring the temperature state, and estimate the time for the mold temperature to reach the target temperature from the temperature at the start of heating and the overshoot temperature from the temperature rise characteristics of both, and within the allowable overshoot temperature range as will be, and the time from the start of heating to completion Atsushi Nobori and setting the timing of switching to high-temperature water from the water vapor such that the shortest.

(3) temperature control method of a molding die of the third means, wherein (2) mold measuring the Atsushi Nobori of from the start of heating by pre Me water vapor of the mold temperature control method, and calculation Calculation of the temperature rise characteristics of the mold, calculation of the temperature rise characteristics by actually measuring the temperature rise condition of the mold with high-temperature water higher than the mold set temperature required during molding, Estimate the time for the mold temperature to reach the target temperature from the temperature at the start of heating and the overshoot temperature to be within the allowable overshoot temperature range, and optimize the time from the start of heating to the completion of the temperature rise characterized by automatically calculating the timing of switching to high-temperature water from the water vapor to.

(4) mold temperature control device of the fourth means, installed water vapor generation means, and hot water generating means, a cooling water generating means, a pipe for sending the mold F heat medium from these means For detecting the temperature of the mold, the temperature control circuit for controlling the temperature of the heating medium of each adjustment temperature generating means to be a set value, the timer for setting the switching timing of each switching valve, and the mold temperature A mold comprising: a temperature detecting means; a control device including a temperature medium selecting circuit for controlling the mold to be rapidly heated and cooled by the methods (1) to (3); and a water storage tank for storing heating water. A heating circuit is provided.

(5) mold temperature controller of the fifth means (4) water vapor generation means is, water that is stored in a pressure vessel high temperature steam or a heater by electrical resistance or high frequency current etc. heated to generate water vapor as a heating means, the water vapor sent to the accumulator by accumulating the water vapor by the high-pressure pump, at the start of heating to rapidly increase the temperature of the mold led to the delivery pipe of the accumulator The switching valve is switched to release water vapor into the mold for a short time.

(6) high frequency mold temperature controller of the sixth means, the water vapor generating means (4) comprises a high-pressure pump to suck the heated water from the water storage tank, which is installed in the water vapor supply pipe heating, a small heating means of the heat pump or the like, the check valve and the water vapor accumulator provided in the pipe, a pressure regulating valve for adjusting the vapor pressure in the accumulator, Ru leads from the accumulator to the switching valve water It consists of a steam piping, the heating water delivered by the high pressure pump and heated at the above-mentioned small heating means during the waiting time of the injection molding into a water vapor, and pressure accumulator is sent to the accumulator, the mold at the start of heating, a short time of water vapor by switching the switching valve connected to the delivery pipe of the accumulator, characterized in that it is a means adapted to release the mold.

(7) mold temperature control device of the seventh means, the water vapor generating means (4) is a pump for sucking up the heating water from the water storage tank, check that bind to the outlet pipe of the pump a valve, the high-frequency heating, an accumulator provided with a built-pressure regulating valve a small heating equipment such as heat pumps, consists of a water vapor piping Ru leads to the switching valve from the accumulator, the heating water fed into the accumulator instead of Rimizu steam by the heating means built into the waiting time of the injection molding pressure accumulator, the heating start to rapidly increase the temperature of the mold, by switching the switching valve to release water vapor accumulator to the mold It is characterized by doing so.

(8) The temperature control device for the molding die of the eighth means incorporates a heating means for heating the heating water sent from the high-pressure pump by the high-temperature water generating means of the mold heating circuit of (4), the hot water is hot water generating tank switching valve is installed in the pipe and the pipe to be sent to the mold, also, small water vapor generating means, adapted to take in high-temperature water of the hot water generator directly heating means a accumulator water vapor generating means also serves with a built-in, the upper part of the accumulator is installed switching valve to the pipe and the pipe for feeding the mold f water vapor, prior Kisui steam generating means serves heating water fed into the accumulator is accumulated by converting by the Rimizu steam heating means incorporated in the waiting time of the injection molding, at the start of heating of the mold to release the water vapor into the mold of the mold Raise temperature rapidly, mold temperature is predetermined Upon reaching temperature, characterized in that so as to raise the mold temperature is switched to high-temperature water of the hot water generator tank to the set temperature.

(9) mold temperature controller of the ninth means, in the mold heating circuit (4) to (8), the water vapor into the mold, hot water, to the common supply pipe cooling water connect the air supply pipe having a switching valve, water vapor into the mold, hot water, when switching the cooling water, hot water send air into the mold manifold or cold water to the respective collecting tank It can be collected.

The inventions according to claims 1 to 3 are temperature control methods for the molding dies of the first to third means, and the inventions according to claim 4 and claim 5 are the first to third inventions. It is a temperature control device for the molding dies of the above-mentioned fourth means and fifth means for carrying out the temperature control method of the molding dies of the means, and the water of high temperature and high heat quantity at the start of heating the mold By combining high-speed heating with steam and relatively gentle heating with high-temperature water after switching the heating medium, overshoot can be suppressed in a short time and the mold can be stably heated to the target temperature. .

Invention according to claim 6 and claim 7 is a molding die temperature control system of the sixth means and the seventh means, by combining the accumulator and the small type water steam generator to temperature control mold , it is possible to supply water vapor, does not need a boiler apparatus which is a large-sized equipment, to reduce the installation area, the effect of reducing the equipment cost. Further, by Ka設the small type water steam generator to an existing mold temperature adjusting apparatus, it is possible to perform rapid heating molding die at low cost.

Invention relating to claim 8 is a mold temperature controller of the means of the eighth, by combining the accumulator and hot water generating means having a built-in small type water steam generating means as a heating device directly Piping is simplified, and the installation area can be further reduced and the equipment cost can be reduced.

The invention according to claim 9 is the temperature control device for the molding die of the ninth means, wherein hot water or cold water in the die is supplied to each of the mold by blowing air into the manifold of the die. because be recovered into the recovery tank can reduce the loss of heat it has the effect of facilitating the supply of water vapor in the next heating cycle.

  A temperature control method of a heating control circuit capable of rapidly heating and cooling in a temperature control of a molding die used for an injection molding machine or the like, and a mold heating apparatus capable of using this temperature control method Three forms of the temperature control device provided will be described. In the mold illustrated in this embodiment, illustrations of the resin injection passage, the injection unit, and the like are omitted, and the configuration and operation method of the heating control circuit are illustrated and described.

(First embodiment)
A first embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram of a mold heating control circuit according to the first embodiment of the present invention, and FIG. 2 shows a heat medium selection procedure in a mold temperature control apparatus provided in the mold heating control circuit of FIG. circuit diagram, FIG. 3 is heated characteristic curve showing the mold temperature rise versus time when heating the mold of Figure 1, Figure 4 when the mold of Figure 1 is heated solely water each steam and hot water FIG. 5 is a diagram showing a process of switching the heating medium when the mold of FIG. 1 is heated.

In the mold heating control circuit 10 of FIG. 1, the pair of molds 11 are in a clamped state, and a mold cavity 12 in which a molded product is molded is formed on the mating surface of the mold 11. Means for heating the mold 11, the water steam generator (the water vapor generating means) 13, hot water generator (hot water generator) is 21, means for cooling the mold 11, the cooling device (cooling water Generating means) 26.

Water steam generator 13, the heating water that is stored in the water storage tank 14 sucked up by the high-pressure pump 15 is supplied to the pressure vessel of the body of water the steam generator 13 via a supply pipe 33, heating the heating water it is configured to generate water vapor. The water storage tank 14 is a heating water supply / recovery tank. 31 is a liquid level meter, which opens the switching valve 43 to replenish water when the liquid level drops beyond the set height range.

Water vapor generated in the water vapor generator 13 is sent to an accumulator 18 which surrounds the outer periphery with a heat insulating material 59 by the high pressure pump 16 and accumulates the water vapor, at the start of heating of the mold 11, the delivery pipe 35 of the accumulator 18 short time water vapor by switching the switching valve 45 that is connected, to release the mold 11. 17 check valve, 19 is a pressure regulating valve of the water vapor which also serves as a pressure relief valve, T1, T3 is a temperature sensor of the water vapor. Water steam temperature detected by the temperature sensor T1, at the mold temperature control unit 40, as compared to the memory water vapor set temperature Tt to the control unit 40, the heat medium is connected to the boiler (not shown) pipe The switching valve 44 installed at 28 is turned on and off, and the heating medium is passed through the heater 13a and controlled so as to have the same set temperature Tt (FIG. 4). The temperature is compared with the set temperature Tt. The detection temperature of the detection sensor T3 may be used.

In FIG. 1, the accumulator 18 is provided with a heat insulating material 59 for heat retention. However, instead of the heat insulating material 59, heat may be maintained using a heating element such as an electric heater (not shown). In this case, the temperature detected by the temperature sensor T3 is compared with memory water vapor set temperature Tt to the mold temperature control unit 40, holding the temperature of the water vapor in the accumulator 18 by heat insulating device of the electric heater or the like (not shown) It is preferable to control so as to.

Further, in FIG. 1, it has a heating medium to the temperature control of the water vapor into the mold 11 as a high-pressure steam from the boiler, the present invention by initial is Ru water steam used to heat the mold 11 since the amount of a small amount, the electric resistance heater in the body of water the steam generator 13, the high-frequency current by induction heaters, if small heating means of the heat pump or the like utilizing the adiabatic compression of the inert gas, It is effective in reducing equipment costs and installation space and saving energy.

  The high-temperature water generator 21 sucks up the heating water stored in the water storage tank 14 by the pump 22 through the supply pipe 36 and supplies it into the pressure vessel of the main body of the high-temperature water generator 21, and the high-temperature water at 100 ° C. or higher. In order to meet these needs, a pressure vessel is used as a main body incorporating a heat exchanger, and a pressure regulating valve 24 and a check valve 23 are provided, which also serve as a pressure safety valve. A switching valve 47 and a temperature detection sensor T2 are installed on the outlet side of the hot water pipe 37. The switching valve 46 installed in the heat medium pipe 34 is turned on and off, and the heat medium is controlled to pass through the heat exchanger so that the high-temperature water reaches the set temperature. In FIG. 1, the high-temperature water generator 21 is a heat exchanger using a heat medium, but a heating device such as an electric heater may be used instead of the heat medium heat exchanger.

  The cooling device 26 sucks up the cooling water stored in the cooling water tank 25 by the pump 27 and supplies it to the inside of the main body of the cooling device 26 through the supply pipe 38. The temperature of the cooling water is set to a low temperature such that the temperature of the molded product filled in the mold cavity 12 is equal to or lower than the solidification temperature of the material of the molded product. A switching valve 49 and a temperature detection sensor T4 are installed in the cooling water pipe 39. The switching valve 48 installed in the refrigerant pipe is turned on and off, and the refrigerant is controlled to pass through the heat exchanger so that the cooling water reaches the set temperature. 32 is a liquid level meter and 56 is a switching valve.

The mold temperature control unit 40 switches the water vapor and hot water, a heat medium selection circuit controlled to rapidly heat the mold, a timer 1 for setting the timing of switching of the switching valve, the cooling water A timer 2 for setting the timing for switching to, and a timer 3 for determining the timing for switching the air drainage from the mold are provided.

  The mold temperature control action will be described with reference to the mold temperature adjustment process diagram of FIG. 5 and the mold temperature heating characteristic curve of FIG. FIG. 5 shows that the temperature of the mold 11 before the plasticizing resin is injection molded into the mold cavity 12 is rapidly increased (rapid heating process), and the heating medium is switched when the mold temperature reaches a predetermined temperature. In this process, the heating rate is moderated (slow heating step), and the mold temperature is controlled to the target temperature by suppressing overshoot.

Heating at the start of the heating medium der Ru water vapor through the delivery pipe 35 is supplied to the heat medium flow passage 11a of the mold 11 to heat the mold 11 by opening the switching valve 45, the discharge tube by opening the switching valve 53 41, the temperature of the mold cavity 12 (the temperature of the surface of the mold cavity 12 detected by the temperature detection sensor TM) reaches a predetermined temperature Tx or the time tx of the timer 1 calculated from the actual measurement. At that time, the switching valves 45 and 53 are closed (rapid heating process). In the next slow heating step, the switching valve 47 is opened, the switching valve 52 is opened and discharged from the discharge pipe 41 to the water storage tank 14, and the heating medium is switched to high-temperature water at or above the mold temperature at the time of molding. The temperature is controlled to the set temperature Tm, and the molten resin is injected after the set time of the timer 2 (tb-tx by switching the timer 1 to the timer 2) when it is estimated that the overshoot is corrected.

  Simultaneously with the injection of the molten resin, the switching valves 47 and 52 are closed to stop the supply of high-temperature water. After holding the timer 3 for an appropriate time (tc-tb), the temperature Ta and / or the injection pressure, the switching valve 52 is opened to supply high-temperature water. The water is drained to the water storage tank 14, and the switching valve 49 is opened to switch to cooling water, and cooled to below the solidification temperature of the resin. When replacing the high-temperature water with the cooling water, the switching valve 52 is first opened to return the high-temperature water stored in the heat medium passage 11a to the water storage tank 14, and the temperature of the waste water from the mold is determined by the temperature detection sensor T5. When it is confirmed that the cooling water has fallen to the above, the switching valve 52 is closed, the switching valve 55 is opened, and the cooling water is recovered into the cooling water tank 25 through the discharge pipe 42.

The water vapor in Figure 1 is generated from the heating water of the water storage tank 14 to be shared with the high temperature water is shown in a configuration for collecting the same storage tank 14, but separate supply water tank of water vapor and hot water to have independent, and the mold 11 water vapor throttle valve 58 discharged from, may be discharged to the outside by opening the switching valve 57.

When it is confirmed that the temperature detection sensor TM on the surface of the mold cavity 12 has dropped below the solidification temperature of the resin, the switching valve 49 of the cooling water pipe 39 is closed and the switching valve 51 for supplying air is opened. Nakadachiryuro expel the cooling water in the 11a be empty, to prevent the heat of the water vapor that will be supplied to the heat medium passages 11a in the next step is taken by the cooling water it is effective in energy saving.

The heat medium selection procedure in the mold temperature control device 40 of FIG. Mold temperature control unit 40 to the heat medium selection circuit 40a, you PID control so that the water steam temperature set temperature Tt (Fig. 4) water steam temperature control circuit 40b, setting the hot water temperature temperature Tu (Fig 4 ), A high-temperature water temperature control circuit 40c that performs PID control, a cooling water temperature control circuit 40d that performs PID control so that the cooling water temperature becomes a set temperature, and a switching output circuit 40e to each switching valve are installed. .

Heat transfer selection circuit 40a, selects the temperature and timing of switching from the heating start of water vapor into the hot water, it is a circuit for setting (FIGS. 2, 3, see Figure 4). Measuring the Atsushi Nobori of the mold cavity 12 side of the heating start by pre Me water vapor (set temperature Tt) (detected by the temperature detection sensor TM), and calculated and to create a Atsushi Nobori characteristics Ts of the mold 11 In addition, the temperature rise state of the mold cavity 12 surface (detected by the temperature detection sensor TM) with high-temperature water (set temperature Tu) higher than the mold temperature required at the time of molding is actually measured to create a temperature rise characteristic Tw. From the temperature rise characteristics (Ts, Tw), the time tb for the temperature of the mold cavity 12 surface to reach the target set temperature Tm from the temperature at the start of heating and the overshoot temperature are estimated, and within the allowable overshoot temperature range. made way, and the time tb from the start of heating to completion of the temperature rise is set the timing tx for switching from the water vapor as possible towards the high-temperature water. If the temperature overshoot is large, the accuracy of temperature adjustment with respect to the target temperature becomes poor and lacks stability. If the set temperature Tu of the high-temperature water is lowered, the time tb to reach the target temperature is increased although the overshoot is small.

Furthermore, by automatically calculating the timing tx that water vapor switched to high-temperature water, it is easy to work, it is effective to increase the work efficiency. Although it is installed in Figure 1 the high pressure pump 16 between the accumulator 18 and the water vapor generator 13, a time that even less need accumulated pressure of the accumulator 18 may be omitted high-pressure pump 16.

(Second Embodiment)
The second embodiment will be described with reference to the schematic diagram of the mold heating control circuit of FIG. The second mold heating control circuit 20 of the embodiment is different from the mold heating control circuit 10 of the first embodiment described above, by integrating the water vapor generating means and an accumulator, configured Fewer parts and cost. Since the high temperature water generating means, the cooling device, and the like other than the above are the same as those in the first embodiment and the mold heating control method is also the same, the description thereof is omitted.

Water steam generating means includes a high pressure pump 15 to suck the hot water from the water storage tank 14 is heated water supply and recovery tank, a check valve 17 which binds to the supply pipe 33 of the high-pressure pump 15, an accumulator 50 with a built-in heating equipment 50a When consists delivery pipe 35. is water vapor piping Ru leading from the accumulator 50 via the switching valve 45 to the mold 11. Although the heating equipment 50a built in the accumulator 50 shows the case of a high-temperature steam snake tube, it may be a small-scale heating equipment such as an electric resistance heater, a high-frequency current heater, or a heat pump instead of the steam snake pipe. A pressure regulating valve 19 that also serves as a safety valve is installed in the delivery pipe 35 of the accumulator 50. Further, the switching valve 44 is compared with the set temperature Tt of water vapor detected value is stored in the mold temperature control unit 40 of the temperature detection sensor T1 for detecting the temperature of the water vapor, ON so that the set temperature Tt, OFF-controlled.

The heating water fed into the accumulator 50 during the waiting time of the injection molding, the heating water by heating equipment 50a to built accumulator in place of water vapor, at the start of heating to raise the temperature of the mold 11 rapidly, the switching valve water steam accumulator 50 is discharged into the mold 11 by switching 45, outlet pipe closes the switching valve 52, and adjusting the rate of by Rimizu steam throttle valve 54 by opening the switching valve 53 the mold 11 The cavity surface is heated.

The water vapor in Figure 6 is generated from the heating water of the water storage tank 14 to be shared with the high temperature water is shown in a configuration for collecting the same storage tank 14, but separate supply water tank of water vapor and hot water to have independent, and, may be discharged outside the water vapor discharged from the mold 11 by opening the switching valve 57.

(Third embodiment)
A third embodiment will be described with reference to the schematic diagram of the mold heating control circuit of FIG. The third embodiment of the mold heating control circuit 30 is different from the mold heating control circuit 10 of the first embodiment described above, connected directly to the hot water generator and water steam generating facility built in the accumulator Arrangement reduces the number of components and reduces costs. Since the cooling device etc. which are parts other than the above are the same as those in the first embodiment and the mold heating control method is also the same, description thereof will be omitted.

As shown in FIG. 7, the high-temperature water generating means of the mold heating control circuit 30 sucks up the heating water stored in the water storage tank 14 by the high-pressure pump 15 and heats the supplied heating water, water vapor generating means also serves the accumulator 60 with a built-in small heating facilities 60a adapted to take in high-temperature water direct hot water generators 65, sends the piping is installed in the water vapor piping to the upper portion of the accumulator 60 35 and a switching valve 45 installed in the pipe 35.

  The high temperature water generator 65 has a built-in heating steam serpentine tube 65a and is a pressure vessel assuming the case of high temperature water, and the switching valve 44 detects a temperature sensor T2 that detects the temperature of the high temperature water in the high temperature water generator 65. The value is compared with the set temperature Tu of the high temperature water stored in the control device, and ON / OFF control is performed so that the set temperature Tu is reached.

Accumulator 60 of water vapor generating means also serves captures the hot water of the previous hot water generator 65 directly generates a by Rimizu vapor in a small heating equipment 60a to built.
In FIG. 7, the small heating facility 60a is a high-temperature steam serpentine tube, but a small-scale heating facility such as an electric resistance heater, a high-frequency current heater, or a heat pump may be used, and the delivery pipe of the accumulator 60 is used. 35 is provided with a pressure regulating valve 19 that also serves as a safety valve. Further, the switching valve 62 is compared with the set temperature Tt of water vapor detected value is stored in the mold temperature control unit 40 of the temperature detection sensor T1 for detecting the temperature of the water vapor, ON so that the set temperature Tt, OFF-controlled.

Water steam generator combined hot water sent into the accumulator 60 of the accumulator is converted into by Rimizu steam heating equipment 60a incorporated in the waiting time of the injection molding, the switch valve 45 at the start of the heating of the mold 11 switching the water vapor of the accumulator 60 is discharged into the mold 11, the discharge pipe 41 on the outlet side is closed switching valve 52, the mold and adjusting the rate of by Rimizu steam throttle valve 54 by opening the switching valve 53 11 cavity surface is heated, and when the mold temperature reaches a predetermined temperature Tx, the switching valve 45 is closed, the switching valve 52 and the switching valve 47 are opened, and the high temperature water generator 65 is switched to the high temperature water. The mold 11 is heated so that the mold temperature is raised to a set temperature.

The water vapor in Figure 7 is generated from the heating water of the water storage tank 14 to be shared with the high temperature water is shown in a configuration for collecting the same storage tank 14, but separate supply water tank of water vapor and hot water to have independent, and, may be discharged outside the water vapor discharged from the mold 11 by opening the switching valve 57.

  Since the present invention mainly focuses on temperature control during the injection molding cycle, the configuration of each part of the mold heating control circuits 10, 20, and 30 is not intended to be limited to what has been described above. Allow to be changed. In addition to this, as long as it does not deviate from the intention of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

It is a schematic diagram of the metal mold | die heating control circuit concerning the 1st Embodiment of this invention. It is a circuit diagram which shows the heating-medium selection procedure in the metal mold | die temperature control apparatus with which the metal mold | die heating control circuit of FIG. 1 was equipped. It is a heating characteristic curve which shows the mold temperature rise with respect to time when the metal mold | die of FIG. 1 is heated. The mold of Figure 1 are two heating characteristic curve showing the mold temperature rise versus time when heating alone each with water vapor and hot water. It is a figure which shows the process of switching a heat medium when heating the metal mold | die of FIG. It is a schematic diagram of the metal mold | die heating control circuit concerning the 2nd Embodiment of this invention. It is a schematic diagram of the metal mold | die heating control circuit concerning the 3rd Embodiment of this invention.

Explanation of symbols

10, 20, 30 ... mold heating control circuit,
11 ... Mold,
11a ... Heat medium flow path,
12 ... mold cavity,
13 ... water steam generator,
18 ... Accumulator,
21, 65 ... high temperature water generator,
26 ... cooling device,
40 ... Mold temperature control device 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 55, 56, 57 ... Switching valve,
50, 60 ... Accumulator (with built-in heater),
54, 58 ... throttle valve,
59… Insulation

Claims (9)

  This is a method of rapidly raising the temperature of the mold before injection molding the plasticized resin into the mold cavity and cooling it to below the solidification temperature after injection, using superheated steam as the heating medium at the start of heating. When the mold temperature reaches a predetermined temperature, or after a predetermined time has elapsed from the start of heating, the heating medium is switched to high-temperature water that is equal to or higher than the mold set temperature at the time of molding, and the mold temperature is raised to the set temperature. After that, the temperature control method for the molding die is characterized in that the supply of high-temperature water is stopped, and the cooling water is switched to cooling to a temperature not higher than the solidification temperature of the resin.   In the temperature control method of the molding die according to claim 1, switching from superheated steam at the start of heating to high-temperature water is performed by measuring and calculating a temperature rise state of the mold from the start of heating by superheated steam in advance. Calculate the temperature rise characteristics of the mold, and at the same time, calculate the temperature rise characteristics by actually measuring the temperature rise condition of the mold with high-temperature water that is higher than the set temperature of the mold required during molding. The time required for the mold temperature to reach the target temperature from the temperature at the start of heating and the overshoot temperature are estimated to be within the allowable overshoot temperature range, and the time from the start of heating to the completion of heating is the shortest The temperature control method for the molding die is characterized in that the timing for switching from superheated steam to high-temperature water is set so that   In the temperature control method of the mold for molding according to claim 2, measurement of the temperature rise state of the mold from the start of heating with superheated steam and calculation of the temperature rise characteristic of the mold calculated in advance, at the time of molding Calculate the temperature rise characteristics by actually measuring the temperature rise condition of the mold with high-temperature water above the required mold set temperature, and the mold temperature reaches the target temperature from the temperature at the start of heating based on the temperature rise characteristics of both Estimate the time and overshoot temperature, and automatically calculate the timing to switch from superheated steam to hot water so that the allowable overshoot temperature range is reached and the time from the start of heating to the completion of heating is optimized A method for controlling the temperature of a mold for molding.   Superheated steam generating means, high temperature water generating means, cooling water generating means, a plurality of switching valves installed in pipes for sending the respective heat medium from these means to the mold, and heat medium for each adjusted temperature generating means A temperature control circuit that controls the temperature of the valve to become a set value, a timer that sets the switching timing of each switching valve, temperature detection means for detecting the temperature of the mold, and claims 1 to 3. A molding die comprising a control device having a temperature medium selection circuit for controlling the die to be rapidly heated and cooled by the above method, and a die heating circuit comprising a water storage tank for storing heating water Temperature control device.   5. The molding die temperature control apparatus according to claim 4, wherein the superheated steam generation means of the mold heating circuit is a high temperature steam from the water stored in the pressure vessel, or a heater by electric resistance or high frequency current. A switching valve connected to the accumulator delivery pipe at the start of heating, which generates superheated steam by heating as heating means, sends the superheated steam to an accumulator by a high-pressure pump, accumulates the superheated steam, and rapidly raises the temperature of the mold Is a means for discharging superheated steam to the mold for a short time by switching the temperature of the mold.   5. The temperature control device for a molding die according to claim 4, wherein the superheated steam generating means includes a high pressure pump that sucks up the heating water from the water storage tank, and a small scale such as high frequency heating and heat pump installed in the superheated steam supply pipe. A heating means, a check valve provided in the pipe, a superheated steam accumulator, a pressure adjusting valve for adjusting the vapor pressure in the accumulator, and a superheated steam pipe leading from the accumulator to the switching valve, The heating water sent by the high-pressure pump is heated by the above-mentioned small-scale heating means during the standby time of injection molding, converted into superheated steam, sent to the accumulator and stored, and when the mold starts heating, the accumulator is sent out. For molding, characterized by switching the switching valve connected to the piping to release superheated steam to the mold for a short time Mold temperature control device.   5. The temperature control device for a molding die according to claim 4, wherein the superheated steam generating means includes a pump for sucking up the heating water from the water storage tank, a check valve coupled to an outlet pipe of the pump, high frequency heating, a heat pump An accumulator equipped with a small-scale heating means and a pressure control valve, and a superheated steam pipe that leads from the accumulator to the switching valve, and the heating water sent to the accumulator is supplied during the standby time of the injection molding apparatus. Molding characterized by accumulating pressure instead of superheated steam by the built-in heating means, and switching the switching valve to release the superheated steam from the accumulator to the mold at the start of heating to rapidly increase the mold temperature. Mold temperature control device.   5. The temperature control apparatus for a molding die according to claim 4, wherein the high temperature water generating means includes heating means for heating the heating water sent from the high pressure pump, and the same pipe as the pipe for sending the high temperature water to the mold. The superheated steam generating tank is equipped with a small heating means which directly takes in the high temperature water of the high temperature water generating means. The accumulator is provided with a switching valve in the same pipe as the pipe for sending superheated steam to the mold at the upper part of the accumulator, and the heating water sent to the accumulator also serving as the superheated steam generating means is waiting time for injection molding It is converted into superheated steam by the heating means built in and accumulated, and when the heating of the mold starts, the superheated steam is released to the mold to rapidly increase the mold temperature, and the mold temperature Once at the prescribed temperature, mold temperature control device being characterized in that switching to high-temperature water so as to raise the mold temperature to a set temperature of the hot water generating tank.   In the molding die temperature control apparatus according to claims 4 to 8, an air supply pipe having a switching valve is connected to a common supply pipe of superheated steam, high-temperature water, and cooling water to the mold, and the mold is connected to the mold. When switching between superheated steam, high temperature water, and cooling water, air is sent into the mold manifold so that hot water or cold water can be collected in each recovery tank. Control device.

Images