JP4091880B2 - Mold temperature controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is synthesized relates mold temperature control machine in the resin molding is used, the heating step and a cooling step molding cycle time (the molded article from the start filled with molten synthetic resin material into the cavity of the mold In addition, the present invention relates to a mold temperature controller that shortens the time until the next material filling preparation is completed, and achieves high thermal efficiency.
[0002]
[Prior art]
A heating process for heating the mold to quickly fill the melted synthetic resin material into the cavity of the mold, and cooling the mold within a short time (to the extent that the molded product does not deteriorate in quality) A mold temperature control method that alternately performs a cooling step of solidifying and taking out a filled synthetic resin material is generally used.
[0003]
As a conventional method for adjusting the temperature of a synthetic resin molding die, a cooling medium is always circulated in the die, and a heating medium is provided in another medium passage provided on the mold surface side only when the synthetic resin material is filled. There is known a temperature control method for circulating the gas (for example, see Patent Document 1).
[0004]
In addition, when a heating medium or a cooling medium is alternately supplied to one medium passage provided in the mold and the heating process and the cooling process are alternately performed, the heating process and the cooling process are switched. A method of using compressed air to discharge the heating medium or cooling medium remaining in the mold to the outside of the apparatus is also known (for example, see Patent Document 2).
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-348041 (pages 3 to 4, FIG. 1)
[Patent Document 2]
Japanese Patent Laid-Open No. 2001-18229 (Claim 19-26, FIG. 8)
[0006]
[Problems to be solved by the invention]
However, since the mold temperature control method of Patent Document 1 performs heating while always cooling the mold, it requires more heating energy than necessary in the heating process, and the thermal efficiency is not necessarily low. I won't.
[0007]
According to the mold temperature adjusting method of Patent Document 2, the heating medium or cooling medium remaining in the mold has thermal energy, and as described in the above publication, this is used as it is. Discharging to the outside is equivalent to wasting heat energy and significantly reducing thermal efficiency.
Also, the compressed compressed air is mixed into the heating medium or cooling medium, which is a liquid, and the heat exchange efficiency in the mold is reduced, so that heating or cooling cannot be performed uniformly in the mold, and the circulation of the medium is prevented. There are also inconveniences such as inhibition.
[0008]
The present invention solves the problems of the above-described conventional mold temperature control method or mold temperature controller, and effectively recycles at least the heat energy of the heating medium without wasting it outside the apparatus. An object of the present invention is to provide a mold temperature controller that can be used and has high thermal efficiency.
In addition, the process cycle time composed of the heating process and the cooling process is shortened, the molding take-out time of the synthetic resin molded product is shortened, and the production efficiency is improved.
[0009]
Further, the mold temperature controller to raise the temperature of the heating medium, when using such as water or ethylene glycol as pressurized heating medium, to raise the boiling point of the heating medium is heated to a temperature without boiling gold It is intended to be used for heat exchange of molds.
[0010]
[Means for Solving the Problems]
To achieve the above object, a mold temperature of regulatory machine according to claim 1 of the present invention, a common medium passage inside a mold for synthetic resin molding through a heating medium or cooling medium is provided, the medium passage the inlet and connect each switching valve to the outlet side, with the switching valve connected to the outlet side of the medium passage is connected to the control panel, the mold temperature control unit and the cooling unit before Symbol switching valve circulation path for circulating the medium between the front Kikin type connected Yes and is formed, converting from the heating medium to the cooling medium at the inlet side of the media path when switching from the heating step to the cooling step or cooling When switching from the process to the heating process, the medium is converted from the cooling medium to the heating medium on the inlet side of the medium passage in the mold, and then the medium flow is delayed on the outlet side of the medium passage by operation of the control panel. The Guide performs cooling step is switched from the mold temperature control unit side to the cooling unit side, the mold temperature control unit comprising to perform the heating process is switched from the cooling unit side to the mold temperature control unit side in the latter,
A heater box is connected between the inlet and the outlet of the medium passage, and a heating medium tank for supplying and returning the heating medium to and from the heater box is provided, and the heating medium can be stored in the heating medium tank. On the other hand, the cooling unit is provided with a cooling medium tank, and is configured to store the cooling medium in the cooling medium tank. The heating medium circulation line including the heating medium tank, The cooling medium circulation line including the cooling medium tank is independent from each other, and has a bypass return path in which the medium does not return to the mold when the heating medium and the cooling medium are switched.
[0011]
As a result, the heating medium remaining inside the mold and the cooling medium heated by exposure to the high temperature of the mold are fed to the mold temperature controller, so that the thermal energy of the medium is transferred to the mold temperature controller. Can be reused and high thermal efficiency can be achieved.
In addition, since the high temperature medium is not supplied to the cooling unit and mixed into the cooling medium in the cooling unit and the temperature of the cooling medium is not raised, the mold can be cooled quickly, and the cooling process time The manufacturing time of the product can be shortened by shortening the time and efficient production is possible.
[0012]
In the present invention, the cooling medium is circulated between the cooling unit and the mold, and when switching from the cooling process to the heating process, the cooling medium is converted from the cooling medium to the heating medium on the inlet side of the medium passage in the mold. the medium flow switching from the cooling unit side to the mold temperature control unit side at the outlet side of the medium passage temporally delayed, the intends line heating step.
[0013]
As a result, the cooling medium remaining inside the mold and the heating medium that has been exposed to the low temperature of the mold and lowered in temperature are fed to the cooling unit, so that in the cooling unit without wasting the thermal energy of the medium. Reusable and can achieve high thermal efficiency.
In addition, since the low temperature medium is not sent to the mold temperature controller and mixed into the heating medium in the mold temperature controller, the temperature of the heating medium is not lowered, so that the mold can be heated quickly. The heating process time can be shortened to shorten the manufacturing time, and efficient production becomes possible.
Furthermore, since the mold can be reliably heated to a predetermined temperature, fluidization of the molten synthetic resin material is promoted, and the quality of the molded product can be improved and the occurrence of defective products can be reduced.
[0014]
In addition , since the high-temperature cooling medium is sent to the mold temperature controller at the initial stage of the cooling process, the medium capacity in the mold temperature controller increases. In order to prevent the increasing medium from being discharged outside the apparatus, this increased amount can be stored in the heating medium tank . Accordingly, it is possible to prevent the heating medium from being unnecessarily lowered in temperature within the mold temperature controller without wasting the medium having thermal energy.
[001 5 ]
In the mold temperature controller according to claim 2 of the present invention, the heating medium tank is formed in a sealed structure, and the heating medium tank is pressurized by pressurized air to raise the boiling point of the medium. the pressure regulating valve for maintaining the internal pressure of the piping between the mold outlet side and the cooling unit is that provided.
[001 6 ]
As a result, since the inside of the heating medium tank is pressurized with pressurized air, the boiling point of the heating medium can be increased (for example, when the medium is water, the boiling point can be set to a value exceeding 100 degrees Celsius). For example, it can be used without boiling at 130 degrees Celsius), and the mold can be heated effectively in a short time.
Further, since the internal pressure of the pipe is kept constant at atmospheric pressure or higher by the pressure regulating valve, the medium can be used without boiling. This configuration exhibits an excellent effect when the medium is water or ethylene glycol.
[00 17 ]
DETAILED DESCRIPTION OF THE INVENTION
Figure 1 is an overall view of a temperature control system of the synthetic resin molding mold used in a mold temperature adjusting apparatus of the present invention. A mold M composed of a fixed mold M1 and a movable mold M2, two mold temperature controllers 1, 1 (one can be used if the heating capacity is high), and one cooling unit 2. And are provided. Hereinafter, only the fixing mold M1 will be taken as the mold, and only the piping of the fixing mold M1, the cooling unit 2, and the mold temperature controller 1 will be described in detail, but the movable mold M2 The same temperature control method is performed by applying the same piping to the above, but the details may be referred to the case of the fixing mold M1.
[00 18 ]
The fixed side mold M1 is provided with a temperature sensor 31, and a temperature adjustment unit 32 is connected to the temperature sensor 31, thereby managing the mold temperature. A medium path (not shown) (not shown in FIG. 4-7) is formed inside the fixed mold M1, and a pipe 33 is connected to the inlet side of the medium path via a flexible hose F1. A pipe 34 is connected to the outlet side of the medium passage via a flexible hose F2.
[00 19 ]
The pipe 33 is connected to the cooling unit 2 via a switching valve V3 including a three-way switching valve, a pipe 22, and a pipe 21. The other connection port of the switching valve V3 is connected to the cooling unit 2 via the pipes 26 and 27 to form a bypass return path.
The piping 27 is provided with a pressure regulating valve Vp so that the internal pressure of the piping 27 is maintained at a constant value.
The pipe 33 is connected to a switching valve V2 including another three-way switching valve. The switching valve V2 is connected to the mold temperature controller 1 through the pipe 11, and the other of the switching valves V2. Is connected to the mold temperature controller 1 through the pipe 16 and the pipe 12 to form a bypass return path.
[002 0 ]
The mold temperature controller 1 is connected to the pipe 34 connected to the outlet side of the medium passage via a switching valve V1 including a three-way switching valve and the pipe 12. The other connection port of the switching valve V <b> 1 is connected to the cooling unit 2 via a pipe 25 and a pipe 27.
The switching valves V1, V2, and V3 including the switching valve can be replaced with a combination of an automatic opening / closing valve and piping.
[002 1 ]
The main flow of the heating medium heated in the mold temperature controller 1 (hot water in this embodiment) is the pipe 11, the switching valve V2, the pipe 33, the flexible hose F1, the fixed side mold M1 (the medium in the mold). Passage), flexible hose F2, piping 34, switching valve V1, and piping 12 in this order are circulated to the mold temperature controller 1.
When the heating medium is not introduced into the fixed mold M1, the heating medium from the mold temperature controller 1 returns to the mold temperature controller 1 via the pipe 11, the switching valve V2, the pipe 16, and the pipe 12. It is circulated through the bypass return route.
[002 2 ]
The main flow of the cooling medium (cold water in the present embodiment) cooled in the cooling unit 2 is as follows: pipe 21, pipe 22, switching valve V3, pipe 33, flexible hose F1, fixed side mold M1, flexible hose. It is circulated to the cooling unit 2 through F2, the pipe 34, the switching valve V1, the pipe 25, and the pipe 27 in this order.
When the cooling medium is not introduced into the fixed mold M1, it is returned to the cooling unit 2 through the pipe 21, the pipe 22, the switching valve V3, the pipe 26, and the pipe 27 and circulated through the bypass return path.
The heating medium and the cooling medium are not simultaneously introduced into the stationary mold M1.
[002 3 ]
FIG. 9 is a cross-sectional explanatory view showing a structural example of the switching valve V1 (V2, V3). For example, the three-way switching valve V1 will be described. One inlet (34a) and two outlets (25a, 16a) are provided in the valve body 38. And the valve body 37 is reciprocated by the solenoid 35 via the piston rod 36 to restrict the outlet of the medium to one of 16a and 25a. The three-way switching valves V2 and V3 have the same structure and operate similarly. The valve body 37 may be driven not only by an electromagnetic type but also by a pneumatic type or other pressure medium type.
[002 4 ]
FIG. 2 is an explanatory diagram of piping showing the internal configuration of the mold temperature controller 1. A heater box 4 for raising the temperature of the heating medium by a heater 44 is provided in the mold temperature controller 1. The heater box 4 has an open relief valve 41, a thermostat 42, a drain plug 43, a cooling pipe 45, and a refrigerant. Pipes 18a, 18b, and 18c, which are pipes that pass through, are attached. The heated heating medium is fed to the mold M via the pipe 15 via the pump 6 and the gate valve V11, the pipe 11 via the switching valve V2,. In FIG. 2, 59 and 60 are regulators.
[002 5 ]
Further, the used heating medium returned from the return port through the switching valve (V1...) Is returned to the heater box 4 via the pipe 12, the gate valve V12, and the pipe 13, and an excessive heating medium is used. It is sent to the heating medium tank 5 described later through the pipe 14.
[002 6 ]
The heater box 4 is connected to a heating medium tank 5 via a pipe 14, and the heating medium L overflowing from the heater box 4 is stored in the heating medium tank 5. The heating medium tank 5 is provided with a float switch 51, a liquid level gauge 52, a pressure gauge 53, and the like.
The heating medium tank 5 is formed in a hermetically sealed structure, and pressurized air is introduced into the internal space via a pipe 19 and is maintained at a pressure exceeding 1 atm. This raises the boiling point of the hot water, which is the heating medium, and allows it to circulate in excess of 100 degrees Celsius. In this embodiment, since the mold temperature is set to 120 degrees Celsius, for example, the hot water temperature is set to 130 degrees Celsius so as not to boil.
[00 27 ]
The heating medium tank 5 is connected to the heater box 4 via the pipe 17 and the pipes 13 and 14, and when the heating medium in the heater box 4 is insufficient, the heating medium tank 5 is replenished from the route through the pipe 13 from the pipe 17. .
As described above, the heating medium tank 5 stores an excess of the heating medium, and as described later, the heating medium is supplemented to the heater box 5 as necessary to avoid a situation where the heating medium becomes insufficient. .
In FIG. 2, 54 and 55 are check valves, 56 is an electromagnetic valve, 57 is a switching valve unit in which switching valves V 1 to V 6 are assembled, and 58 is a control panel connected to the switching valve unit 57. When switching from the heating step to the cooling step, the heating medium is converted to the cooling medium at the inlet side of the medium passage, or when switching from the cooling step to the heating step, the cooling medium is changed from the cooling medium to the heating medium at the inlet side of the medium passage in the mold. Then, by operating the control panel 58, the medium flow at the outlet side of the medium passage is later delayed, and the former is switched from the mold temperature controller 1 side to the cooling unit 2 side to perform the cooling process. In the latter case, the heating process is performed by switching from the cooling unit 2 side to the mold temperature controller 1 side.
FIG. 10 is a side view showing an actual machine of the mold temperature controller 1, and shows a heating medium tank 5 provided above the apparatus.
[00 28 ]
The cooling unit 2 shown in FIG. 1 can savings distillate cooling medium using a general-purpose ones (comprising a coolant tank 28 shown in FIG. 4-7), the cooling medium exchanges heat with cold water, if necessary Use a cooling system that only cools or a system that uses forced cooling with refrigerant gas.
[00 29 ]
Below, the temperature control method of the metal mold | die by the heating and cooling system shown in FIG. 1 is demonstrated. FIG. 3 is a graph showing one cycle of temperature change in the mold cavity of the mold M, that is, the fixed side mold M1. The temperature change of the movable mold 2 is the same. The synthetic resin material filling, holding pressure, cooling solidification, mold opening, and taking-out steps are performed during this one cycle. In addition, in the structure from a temperature surface, it is comprised from one heating process and a cooling process. That is, the heating medium (warm water) is mainly fed from the mold temperature controller 1 to the mold M1 in the heating process, and the cooling medium (cold water) is mainly fed from the cooling unit 2 to the mold M1 in the cooling process.
[003 0 ]
First, in the case of conversion from the heating process (FIG. 4 is the end of the heating process) to the cooling process (FIG. 5 is the initial stage of the cooling process), the switching valves V2 and V3 on the inlet side of the mold M1 are switched at the start of conversion. The heating medium flowing into the mold M1 is converted into a cooling medium (change from FIG. 4 to FIG. 5).
At the time of this conversion, the heating medium remains in the medium passage B of the mold M1, and the temperature of the mold M1 remains high, and the cooling medium is immediately heated and discharged from the mold M1. It will be. Therefore, if the high-temperature cooling medium is returned to the cooling unit as it is, a large amount of heat energy is required to cool the cooling medium.
[003 1 ]
Therefore, at the initial stage of conversion from the heating process to the cooling process, as shown in FIG. 5, the switching valve V1 on the outlet side of the mold M1 is held as it is in the heating process, and the heating medium remaining in the mold and the remarkably The cooled cooling medium is fed to the mold temperature controller 1. At this time, the heating medium is circulated to the mold temperature controller 1 via the bypass return path passing through the pipe 16 and the pipe 12 by the switching valve V2. Therefore, although the heating medium sent to the mold temperature controller 1 increases, this is stored in the heating medium tank 5 provided in the mold temperature controller 1. In addition, since the cooling medium does not return to the cooling medium tank 28 provided in the cooling unit 2, one having a sufficient capacity is employed.
[003 2 ]
When the mold temperature reaches a predetermined temperature, or after a predetermined time has passed by a timer, as shown in FIG. 6, the switching valve V1 provided on the outlet side 34 of the mold M1 is switched, and the cooling medium is pipe 25 , 27 is returned to the cooling unit 2, and the cooling medium circulates between the cooling unit 2 and the mold M1, and cools until the synthetic resin molded product can be solidified and taken out.
[003 3 ]
Further, when converting from the cooling process to the heating process, as shown above, as shown in FIG. 7, first, the switching valve V2. V3 is switched, and the medium introduced into the medium passage B of the mold M1 is changed from the cooling medium to the heating medium. In the initial stage of the heating process, the switching valve V1 of the pipe 34 on the outlet side in the mold M1 is kept in the cooling process, and the cooling medium remaining in the medium passage B and the heating medium remarkably cooled are transferred to the cooling unit 2. This prevents the wasted heat energy from being wasted from heating the medium.
At this time, the cooling medium fed from the cooling unit 2 is circulated to the cooling unit 2 through a bypass return path passing through the piping 26 and the piping 27 from the switching valve V3. Therefore, the storage amount of the cooling medium tank 28 in the cooling unit 2 increases.
[003 4 ]
Then, the temperature of the mold M1 drops to a predetermined temperature or is delayed for a predetermined time by a timer circuit or the like, and the switching valve V1 in the outlet side pipe 34 in the mold M1 is switched, as shown in FIG. The heating medium passing through the medium passage B returns to the mold temperature controller 1 through the switching valve V1 and the pipe 12, and the heating medium circulates between the mold temperature controller 1 and the mold M1.
[003 5 ]
Symbols Z4, Z5, Z6, and Z7 shown in the graph of FIG. 3 correspond to the medium flow paths shown in FIGS. 4, 5, 6, and 7, respectively, and the temperature control of the present invention in the heating and cooling steps. The method is shown.
FIG. 8 is an explanatory diagram showing the switching state of the switching valves V1, V2, and V3. As for the switching delay time in the switching valve V1, the delay time t1 at the time of conversion from the heating process to the cooling process and the delay time t2 at the time of conversion from the cooling process to the heating process can be arbitrarily set. In order to maintain the balance between the heating medium amount and the cooling medium amount in the heating / cooling system, the product of the cooling medium flow rate per unit time and the delay time t1 and the product of the heating medium flow rate per unit time and the delay time t2 are used. It is recommended to set to be equal.
[003 6 ]
In the above embodiment, the delay times t1 and t2 are set within a range from several seconds to several tens of seconds, but these can be changed depending on the type of synthetic resin material to be molded, the size of the mold, and the type. Also, instead of setting the delay time with a timer circuit, the mold temperature is measured by a temperature sensor, and it is detected that the temperature is heated or lowered to a predetermined temperature to set the delay timing. good.
The mold temperature controller 1 and the cooling unit 2 are provided with a medium overflow mechanism so that an abnormal increase in the medium is discharged to the outside of the apparatus and the shortage can be compensated for by the medium supply mechanism. It is preferable.
[00 37 ]
In addition, the mold temperature adjusting method and the mold temperature adjusting machine described above are not only applied to the injection molding method, but also the trasper molding method, blow molding method, gas press method, compression molding method, reaction injection molding method, heat Applicable to molding method.
Furthermore, the injection molding methods include injection compression method, local vibration pressurization method, gas press method, gas assist method, hollow molding method, sandwich molding method, two-color molding method, in-mold molding method, push-pull molding method, high-speed injection method It can be applied to molding methods.
[00 38 ]
【The invention's effect】
According to the first aspect of the present invention, the heat energy of the medium that has been heated is reused in the mold temperature controller without wastefully discharging, so that a molded product can be manufactured with high thermal efficiency. In addition, since the temperature of the cooling medium in the cooling unit is not increased unnecessarily and the cooling efficiency is not lowered, the mold can be cooled quickly, and the production time of the product can be shortened and efficient production can be achieved.
In addition , since the heat energy of the heat medium that has been lowered in temperature is reused in the cooling unit without being released outside the apparatus, high thermal efficiency can be achieved.
Moreover , since the temperature of the heating medium in the mold temperature controller is not unnecessarily lowered, the mold can be quickly heated to shorten the product manufacturing time. Moreover, it is less likely to cause deterioration of product quality due to heating failure or cooling failure, and the generation of defective products can be reduced.
Furthermore, the increased amount of medium sent to the mold temperature controller can be reused without being discarded, and operation with high thermal efficiency is possible. Further, it is possible to reduce the temperature of the heating medium to a minimum and shorten the product manufacturing time.
[00 39 ]
According to the second aspect of the present invention, the boiling point temperature of water, ethylene glycol, or the like can be set high, and can be fed to the mold without boiling at a high temperature, so that efficient mold heating can be performed. In particular, when water is used as the heating medium, the hot water temperature can be circulated at a high temperature such as 130 degrees Celsius.
[Brief description of the drawings]
1 is an overall view of a synthetic resin molding die temperature control system which need use the mold temperature regulating apparatus of the present invention.
Figure 2 is an internal configuration diagram of a mold temperature regulatory machine used in the present invention.
FIG. 3 is a graph showing a change in the mold temperature definitive in this onset Akira.
4 is an explanatory diagram showing a flow path of a heating medium and cooling medium definitive to the onset bright.
5 is an explanatory diagram showing a flow path of the definitive heating medium and the cooling medium to the onset bright.
6 is an explanatory diagram showing a flow path of the definitive heating medium and the cooling medium to the onset bright.
7 is an explanatory diagram showing a flow path of the definitive heating medium and the cooling medium to the onset bright.
8 is an explanatory diagram showing a conversion timing of the onset definitive bright three-way selector valve.
FIG. 9 is an explanatory cross-sectional view showing a structural example of a three-way switching valve.
FIG. 10 is a side explanatory view of a mold temperature controller of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Mold temperature controller 2 Cooling unit 4 Heater box 5 Heating medium tank 6 Pump 11, 12, 13, 14, 15, 16, 17, 21, 22, 25, 26, 27, 33, 34 Piping
28 Cooling medium tank B Medium passage F1, F2 Flexible hose M Mold M1 Fixed mold M2 Movable mold V1, V2, V3, V4, V5, V6 Switching valve Vp Pressure regulating valve

Claims (2)

The common media path through the heating medium or cooling medium to the interior of the mold for synthetic resin molding provided, each connecting the switching valve to the inlet side and the outlet side of the medium passage, and connected to the outlet side of the medium passage with the switching valve is connected to the control panel, Yes circulating path for circulating the medium between the front Symbol switching the mold by connecting mold temperature control unit and the cooling unit in the valve is formed, wherein When switching from the heating process to the cooling process, the heating medium is converted from the cooling medium on the inlet side of the medium path, or when switching from the cooling process to the heating process, the cooling medium is converted from the cooling medium to the heating medium at the inlet side of the medium path in the mold. Then, after the operation of the control panel, the medium flow is switched from the mold temperature controller side to the cooling unit side at the outlet side of the medium passage at a later time, and the cooling step Performed, the mold temperature control unit comprising to perform the heating process is switched from the cooling unit side to the mold temperature control unit side in the latter,
A heater box is connected between the inlet and the outlet of the medium passage, and a heating medium tank for supplying and returning the heating medium to and from the heater box is provided, and the heating medium can be stored in the heating medium tank. On the other hand, the cooling unit is provided with a cooling medium tank, and is configured to store the cooling medium in the cooling medium tank. The heating medium circulation line including the heating medium tank, Mold temperature control characterized by having a bypass return path that is independent of the coolant circulation line including the coolant medium tank and prevents the medium from returning to the mold when the heating medium and the coolant are switched. Machine. The heating medium tank is formed in a sealed structure, and the heating medium tank is pressurized by pressurized air to raise the boiling point of the heating medium, and the internal pressure of the pipe between the outlet side of the mold and the cooling unit. The mold temperature controller according to claim 1, wherein a pressure regulating valve for holding the mold is provided.

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