JP2011178149A - Mold unit for molding resin and temperature control method of mold for molding resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold unit for molding resin and a temperature control method of mold for molding resin wherein a precise resin molding can be obtained, and initial cost and running cost can be reduced by surely preventing occurrence of welding lines or transfer failure, by controlling the temperature only around a molding cavity. <P>SOLUTION: The molding cavity 5 is formed in a pair of molds 2A, 2B for molding resin of the mold unit 1 for molding resin by a pair of inserts 3A, 3B heat-insulated by a heat insulating space 7. A heated medium or a cooled medium is fed to medium passages 6A, 6B from a heating/circulating means 8 and a cooling/circulating means 9, and a so-called heat cycle is formed by repeated heating and cooling of only the inserts 3A, 3B, thus surely preventing the molding failure such as welding lines or transfer failure, and saving energy. Heating and cooling are switched by a control means 12 by receiving signals from an inexpensive thermocouple 10 high in the response speed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin molding die unit having a resin molding die for molding a resin molded product such as an injection molding die and a temperature control mechanism thereof, and a temperature control method for the resin molding die. It is about.

In injection molding using a synthetic resin as a molding material, various molding defects may occur depending on molding conditions and the shape of a resin molded product. For example, in a resin molded product having a through hole or a resin molded product having an angular step, a weld line may be formed by the flow of the molten resin divided in the through hole joining behind the through hole. The weld line may also be formed by filling the melted resin in the remaining corners after filling the melted resin leaving the corners of the steps.
In addition, when molding thin resin molded products or using synthetic resins with high melting points such as engineering plastics as molding materials, molding defects such as short shots and improper transfer occur, resulting in precise resin molding. There was also a problem that goods could not be obtained.

In Patent Document 1, such a weld line formation, short shot, transfer failure, and the like are prevented, and the occurrence of burrs from the parting surface of the mold is suppressed, and the appearance is good and a precise resin molded product. To fill the cavity with molten resin, the mold temperature is kept high and the so-called heat cycle molding method of cooling the mold upon completion of filling is performed, and only the parting surface of the mold is The present invention discloses a mold apparatus and a molding method that are always cooled.
However, in the technique disclosed in Patent Document 1, the timing for switching the mold from heating to cooling is after the molten resin is filled in the cavity and the pressure holding is started. However, the molding cycle becomes longer and the pressure holding start signal needs to be taken out from the injection molding machine, so that there is a problem that the surroundings of the apparatus become complicated due to the wiring for that purpose.

Therefore, in order to solve such a problem, in Patent Document 2, an infrared temperature sensor for measuring the temperature of the resin in the cavity is provided in the mold, and the temperature of the resin in the cavity is monitored in real time. The invention discloses an invention of an injection molding method and a mold temperature control device characterized by switching between heating and cooling of a mold when the temperature of the resin reaches a predetermined temperature set in advance.
This makes it possible to accurately measure the resin temperature, accurately determine the timing of filling completion, and advance the cooling start timing, thereby shortening the cooling time and improving productivity. Since it is not necessary to take out a signal line from the control panel, the surroundings of the apparatus are not complicated, and it can be easily applied to injection molding machines of different manufacturers.

JP 2005-297386 A JP 2009-137075 A

  However, in the technique described in Patent Document 2, since an infrared temperature sensor is used as a means for accurately measuring the temperature of the resin in the cavity in real time in order to determine the cooling timing, the equipment cost is high. Become. In addition, since the mold temperature control flow path for heating and cooling the mold by flowing the heating medium and the cooling medium is provided over the entire movable mold, not only the necessary cavity periphery but also the movable mold As a result, it is necessary to heat and cool the entire structure, which wastes heat energy. As a result, there is a problem that both initial cost and running cost increase.

  Therefore, the present invention has been made to solve such a problem. By controlling the mold temperature only around the cavity, which is necessary to reduce the equipment cost, it is possible to surely generate weld lines and transfer defects. It is an object of the present invention to provide a resin molding die unit and a temperature control method for the resin molding die that can prevent a precise resin molded product and reduce both initial cost and running cost.

  A mold unit for resin molding according to claim 1 is a resin molding for forming a molding cavity for molding a resin molded product made of a synthetic resin with a molten synthetic resin (hereinafter also referred to as “molten resin”). A mold unit for resin molding having a mold, wherein a nest for forming the molding cavity provided in the mold for resin molding and a temperature control medium provided in the nest are passed through 1 or Two or more medium passages, heat insulating means for insulating between the insert and the resin molding die excluding the insert, heating / circulation means for heating and circulating the temperature control medium, Cooling / circulation means for cooling and circulating the temperature control medium, heating medium piping connecting the medium passage and the heating / circulation means, and cooling connecting the medium passage and the cooling / circulation means Medium piping and before nesting A cavity temperature measuring means provided in the vicinity of the molding cavity for measuring the temperature in the molding cavity; and when the temperature in the molding cavity measured by the cavity temperature measuring means falls below a predetermined lower limit temperature, the cooling and The flow of the cooled medium from the circulation means is interrupted, the medium heated from the heating / circulation means is caused to flow into the medium passage, and the temperature in the molding cavity measured by the cavity temperature measurement means is a predetermined upper limit. When the temperature exceeds the temperature, the heating / circulation means and the cooling / circulation are stopped so as to interrupt the flow of the heated medium from the heating / circulation means and allow the medium cooled by the cooling / circulation means to flow through the medium passage. Control means for controlling the means.

Here, “synthetic resins” are roughly classified into thermoplastic resins and thermosetting resins, and thermoplastic resins can be further classified into general-purpose plastics, engineering plastics (hereinafter also referred to as “engineer plastics”), and super engineering plastics. . In the present specification and claims, so-called fiber reinforced plastic (FRP) is also included in the “synthetic resin”.
General-purpose plastics include polyethylene (PE: high density, medium density, low density), polypropylene (PP), polyvinyl chloride (PVC), polyvinylidene chloride, polystyrene, polyvinyl acetate, ABS (acrylonitrile, butadiene, styrene copolymer) ) Resin, AS (acrylonitrile, styrene) resin, acrylic resin, fluorine resin such as PFA, FEP, and the like.

Engineering plastics include polyamide (nylon, etc.), polyacetal, polycarbonate, modified polyphenylene ether, polyethylene terephthalate (PET), polybutylene terephthalate, glass fiber reinforced polyethylene terephthalate (GF-PET), which is a kind of FRP, and cyclic polyolefin. is there.
Furthermore, super engineering plastics include polyphenylene sulfide, polytetrafluoroethylene (PTFE), polyether ether ketone (PEEK), polysulfone, polyether sulfone, amorphous polyarylate, liquid crystal polymer, thermoplastic polyimide, polyamideimide, and the like. .
On the other hand, examples of the thermosetting resin include phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, and thermosetting polyimide.

  “Resin molding molds” include injection molding molds, transfer molding molds, blow molding (hollow molding) molds, compression molding molds, and the like. Although it is configured by a pair of molds (a fixed mold and a movable mold), the resin molding mold may be configured by three or more molds.

Furthermore, “cavity” of “molding cavity” here is a term for injection molding technology. “In English, Cavity means a hole (concave), and Core means a core or nest (convex). In general, the cavity is often used as the fixed side and the core as the movable side. (Kyoyo Arikata, “Measures against defects in injection molding”, pages 15-17, published by Nikkan Kogyo Shimbun, November 30, 2003), but in the present specification and claims, As illustrated on page 17 of the above book, the term “cavity” is used to mean “the mold space itself into which the molten resin enters”.
Note that only one molding cavity may be formed in the resin molding die, or a plurality of molding cavities may be formed.

Furthermore, the term “Ireko” is used in various meanings depending on the technical field, but in this specification and claims, “Molding method (new edition)” (Rokuya Takagi) As described in page 55 of the book, published on June 30, 1980, published by Nikkan Kogyo Shimbun), it means an important part of a mold that forms a mold carved portion (molding cavity).
In general, a pair of nests is provided to form one molding cavity, but a nest divided into three or more can be used to form one molding cavity. In addition, a combination of nestings forming one molding cavity (a pair of nestings or nestings divided into three or more) is formed when a plurality of molding cavities are formed in a resin molding die. The same number of cavities will be provided.

  In addition, the “heat insulating means” is formed between the insert and the resin molding die excluding the insert, or between the insert and the resin mold except the insert. There are spaces such as gaps and grooves. Furthermore, as the heat insulating material, fiber heat insulating materials such as glass wool, rock wool, wool heat insulating material and cellulose heat insulating material, foamed heat insulating materials such as urethane foam, phenol foam and polystyrene foam, extruded polystyrene (XPS), vacuum heat insulating material. There are materials.

The “medium passage” may be provided in all the inserts when there are a plurality (one or more pairs) of inserts forming one molding cavity. The medium passage may be provided as a through hole so as not to communicate with the molding cavity inside the insert, or may be provided in a pipe shape surrounding the periphery of the insert.
Further, the medium passage through which the heated medium flows and the medium passage through which the cooled medium flows may be provided separately from each other, and the medium to be heated and the medium to be cooled are made of the same substance. If there is no problem even if both media are mixed, a common media path may be used.

Examples of the “temperature control medium” include water, liquid nitrogen, organic solvent, oil (for example, dibenzyltoluene), water vapor, air, nitrogen gas, and the like.
Furthermore, “heating / circulation means” includes a structure in which a metal pipe such as a copper pipe is surrounded by a heater and a circulation pump such as a diaphragm pump or a hose pump. As the means, there is a combination of a structure in which a metal pipe such as a copper pipe is wrapped around a chiller (a refrigerator using a chlorofluorocarbon refrigerant) and a circulation pump such as a diaphragm pump or a hose pump.

As the “heating medium piping” and “cooling medium piping”, metal piping such as copper pipes, engineering plastic or super engineering plastic pipes that can withstand heating and cooling, and the like can be used.
Furthermore, as the “cavity temperature measuring means”, a thermocouple, a resistance temperature detector, or the like that is less expensive than an infrared temperature sensor can be used.

The “control means” includes an input port to which an electrical signal output from the cavity temperature measurement means is input, an A / D converter that converts an electrical signal that is an analog signal into a digital signal, and a central processing unit (CPU). ) And a computing unit having a memory device, a D / A converter that converts a digital signal indicating a computation result in the computing unit into an electrical signal that is an analog signal, and an output port that outputs the electrical signal, etc. Can be used.
Furthermore, since the operation of flowing the cooled medium from the cooling / circulation unit has not yet been performed at the start of operation of the resin molding die unit, the temperature in the molding cavity measured by the cavity temperature measuring unit is a predetermined lower limit. When the temperature falls below, initially, only the operation of flowing the heated medium from the heating / circulation means into the medium passage is performed.

A mold unit for resin molding according to a second aspect is the structure of the first aspect, wherein the cavity temperature measuring means is a thermocouple or a resistance temperature detector.
Here, “thermocouple” means “an element that uses thermoelectromotive force to measure heat and temperature. It consists of a set of two alloys or pure metals. Since it is a temperature difference that can be measured with a thermocouple, the temperature can be measured if the temperature of one contact is kept constant. … ”(Saburo Nagakura et al., Edited by“ Iwanami Dictionary of Physical and Chemical Dictionary (5th edition) ”, page 1018, published on February 20, 1998 by Iwanami Shoten).
The “resistance temperature detector” is a temperature sensor that utilizes the change in metal resistance depending on the temperature. Among them, platinum (Pt) has a linear relationship between temperature and metal resistance compared to other metals. Also, the temperature coefficient is large and excellent for temperature measurement.

  The resin molding die unit according to claim 3 is a resin molding die unit having a resin molding die for forming a molding cavity for molding a resin molded product made of the synthetic resin with a molten synthetic resin. An insert for forming the molding cavity provided in the resin molding die, one or more medium passages for passing a temperature control medium provided only in the insert, and the insert And heat insulation means for insulating between the resin mold except for the insert, heating / circulation means for heating and circulating the temperature control medium, and cooling the temperature control medium. Cooling / circulation means for circulation, heating medium pipe connecting the medium passage and the heating / circulation means, cooling medium pipe connecting the medium passage and the cooling / circulation means, and the resin molding die Is detected to open A mold opening detecting means for outputting an opening signal, a cavity filling detecting means for detecting that the molding cavity is filled with the molten resin and outputting a cavity filling signal, and a mold opening signal from the mold opening detecting means. When this is done, the flow of the cooled medium from the cooling / circulation means is interrupted, and the medium heated by the heating / circulation means is caused to flow through the medium passage, and a cavity filling signal is output from the cavity filling detection means. The heating / circulation means and the cooling / circulation means so that the flow of the heated medium from the heating / circulation means is interrupted and the medium cooled from the cooling / circulation means is caused to flow through the medium passage. And control means for controlling.

Here, as the “mold opening detection means”, a known contact sensor, proximity sensor, or the like can be used. In the case where the resin molding die is formed of a pair of fixed side mold and movable side mold, a pair of contact sensors and a pair of proximity are provided for each of the fixed side mold and the movable side mold. Sensors can be attached, but if the resin mold is a combination of three or more molds, the mold opening detection means detects that the insert forming the molding cavity has opened. It needs to be installed as possible.
In addition, when the mold unit for resin molding is started, the operation of flowing the cooled medium from the cooling / circulation means has not been carried out yet, so when the mold opening signal is output, the heating / circulation is initially performed in the medium passage. Only the flow of the heated medium from the means is carried out.
Furthermore, as the “cavity filling detection means”, for example, a pressure sensor may be installed at the end portion of the molding cavity (the portion farthest from the gate of the molding cavity), or in the vicinity of the end portion of the molding cavity. As in the invention according to claim 1, cavity temperature measuring means may be installed in the nest.

  According to a fourth aspect of the present invention, there is provided a mold unit for resin molding according to any one of the first to third aspects, wherein the medium is heated by the heating / circulating means and the medium is cooled by the cooling / circulating means. Is a medium made of the same substance, and switching means for flowing the medium passing through the medium passage and out of the insert into either the heating / circulation means or the cooling / circulation means, and the medium passage Medium temperature measuring means for measuring the temperature of the medium passing through the insert and passing through the insert, and if the temperature of the medium measured by the medium temperature measuring means is equal to or higher than a predetermined temperature, the medium is heated and Switching control means for controlling the switching means so as to flow the medium to the cooling / circulating means if the temperature of the medium measured by the temperature measuring means is less than a predetermined temperature. It is intended.

Here, the “medium made of the same substance” means the same organic solvent if the medium is liquid in the heated state or the cooled state, and the same oil if the medium is in the heated state. In the case of a gas, it means that it is made of the same H ₂ O substance such as water vapor and water.
As the “switching means”, a three-way valve, a three-way solenoid valve, or the like can be used.

Furthermore, as the “medium temperature measuring means”, a thermocouple or a resistance temperature detector is placed in contact with the pipe in the vicinity of the nest of the heating medium pipe and the cooling medium pipe connected to the outlet side of the medium passage. Alternatively, means such as directly measuring the medium temperature by inserting a thermocouple or a resistance temperature detector into the pipe can be used.
The “switching control means” includes an input port to which an electric signal output from the medium temperature measuring means is input, an A / D converter that converts an electric signal that is an analog signal into a digital signal, and a central processing unit ( CPU) and a computing unit having a memory device, a D / A converter that converts a digital signal indicating a computation result in the computing unit into an electrical signal that is an analog signal, and an output port that outputs the electrical signal Etc. can be used.

The mold unit for resin molding according to claim 5 is the structure of claim 4, wherein the predetermined temperature is a softening temperature or a glass transition temperature of the synthetic resin.
Here, the “softening temperature” is “a softening temperature indicates how many times the polymer becomes soft, and is an important characteristic in practical use. A frequently used test method is the deflection temperature under load (DTUL). A test piece having a predetermined shape is placed horizontally, a predetermined load is applied to the center, the temperature of the test piece is increased at a constant speed, and the temperature at which the deflection reaches a predetermined value is defined as DTUL. …… ”(The Chemical Society of Japan, edited by“ Chemical Handbook Applied Chemistry (6th edition) ”, page 809, published by Maruzen Co., Ltd. on January 30, 2003).

  A resin molding die unit according to a sixth aspect is the structure according to any one of the first to fifth aspects, wherein the resin molding die has a gate cavity for guiding the molten resin to the molding cavity. A cylinder portion provided in the resin mold and provided in a portion of the molding cavity away from the gate cavity, a piston portion slidably fitted in the cylinder portion, and a piston portion formed integrally with the cylinder portion And a gas vent comprising a closing member having a tip portion constituting a part of the molding cavity, the cylinder portion communicates with the outside of the resin molding die, and the gas vent When the resin tip passes through the gate cavity, it is open, and the tip of the closing member is pressed by the pressure of the molten resin. Serial closure member is intended to be closed by sliding.

Here, the “gate cavity” means, for example, in an injection mold, a sprue that is a runway through which molten resin enters from a nozzle of an injection molding machine, a gate that is a gate (inlet) of a molding cavity, and It is a concept that includes all runners that run from the sprue to the gate.
“Gas vent” is a mechanism for releasing the gas generated from the air or molten resin in the molding cavity to the outside. The gas vent can be mechanically closed by the pressure of the molten resin flowing into the molding cavity. If it is. It should be noted that where the gas vent is disposed in the resin mold and the insert and where the gas vent is disposed away from the gate cavity is arbitrarily selected depending on the mold configuration. is there.

The temperature control method for a resin molding die according to claim 7 is a temperature control method for a resin molding die for forming a molding cavity for molding a resin molded product made of the synthetic resin with a molten synthetic resin. The resin molding die is provided with an insert for forming the molding cavity, and only one or more media passages for passing a temperature control medium are provided only in the insert. Insulate the resin molding die excluding the child and indirectly measure the temperature in the molding cavity, and when the temperature in the molding cavity falls below a predetermined lower limit temperature, the medium passage is cooled at a low temperature. The medium flow is interrupted and a high temperature heating medium is supplied to the medium passage. When the temperature in the molding cavity exceeds a predetermined upper limit temperature, the supply of the high temperature heating medium to the medium passage is interrupted and the medium is stopped. Low temperature coolant in the passage The flowing, in which flow the heating medium of the low temperature and the high temperature of the heating medium alternately to the medium passage.
Here, at the start of the operation of the resin molding die, since the operation of flowing a low-temperature cooling medium through the medium passage has not yet been performed, when the temperature inside the molding cavity falls below a predetermined lower limit temperature, the medium passage is initially Only the operation of flowing a high-temperature heating medium is performed.

The temperature control method for a resin molding die according to claim 8 is a temperature control method for a resin molding die for forming a molding cavity for molding a resin molded product made of the synthetic resin with a molten synthetic resin. The resin molding die is provided with an insert for forming the molding cavity, and only one or more media passages for passing a temperature control medium are provided only in the insert. Heat insulation with the resin mold except for the child, and when the resin mold is opened, the flow of the low-temperature cooling medium to the medium passage is interrupted and the high-temperature heating medium is caused to flow to the medium path. When the molten resin is filled in the molding cavity, the high temperature heating medium and the low temperature heating medium are stopped by interrupting the flow of the high temperature heating medium through the medium passage and the low temperature cooling medium through the medium passage. Alternately in the medium path It is.
Here, at the start of the operation of the resin molding die, the operation of flowing a low-temperature cooling medium through the medium passage has not yet been carried out. Therefore, when the resin molding die is opened, a high-temperature heating medium is initially placed in the medium passage. Only the operation of flowing is performed.

  According to a ninth aspect of the present invention, there is provided the resin molding die temperature control method according to the seventh or eighth aspect, wherein the heating medium and the cooling medium are made of the same material, and the resin molding die. A heating means for heating the medium connected to the medium passage and a cooling means for cooling the medium are disposed outside the medium, and the temperature of the medium passing through the medium passage and coming out of the nest When the temperature is equal to or higher than a predetermined temperature, the medium is flowed to the heating means, and when the temperature is lower than the predetermined temperature, the medium is flowed to the cooling means.

  According to a tenth aspect of the temperature control method for a resin molding die according to the ninth aspect, the predetermined temperature is a softening temperature or a glass transition temperature of the synthetic resin.

  The temperature control method for a resin molding die according to claim 11 is the structure according to any one of claims 7 to 10, wherein the resin molding die is a gate cavity for guiding the molten resin to the molding cavity. And a gas vent provided in a portion of the molding cavity away from the gate cavity, the gas vent communicates with the outside of the resin molding die, and the gas vent is a tip of the molten resin. Is opened at the time of passing through the gate cavity, and is closed by the pressure of the molten resin.

  The resin molding die unit according to claim 1 is a resin molding die unit having a resin molding die for forming a molding cavity for molding a resin molded product made of synthetic resin with molten synthetic resin. An insert for forming a molding cavity provided in the resin mold, one or more medium passages for passing a temperature control medium provided in the insert, and a resin excluding the insert and the insert. Heat insulation means for insulating between the molds, heating / circulation means for heating and circulating the temperature control medium, cooling / circulation means for cooling and circulating the temperature control medium, and medium passage Heating medium piping connecting the heating and circulation means, cooling medium piping connecting the medium passage and the cooling / circulation means, and a cavity for measuring the temperature in the molding cavity provided in the vicinity of the molding cavity of the insert Temperature measuring means and When the temperature in the molding cavity measured by the cavity temperature measuring means falls below a predetermined lower limit temperature, the flow of the cooled medium from the cooling / circulation means is interrupted, and the medium heated from the heating / circulation means to the medium passage When the temperature in the molding cavity measured by the cavity temperature measuring means exceeds a predetermined upper limit temperature, the flow of the heated medium from the heating / circulation means is interrupted, and the cooling / circulation means is cooled to the medium passage. And a control means for controlling the heating / circulation means and the cooling / circulation means so as to cause the medium to flow.

In this way, a medium passage for passing the temperature control medium is provided only in the nest that is insulated from the surroundings, and the medium heated by the heating / circulation means flows through the medium passage through the heating medium pipe. Only the child is heated, and the medium cooled by the cooling / circulation means flows through this medium passage through the cooling medium pipe, so that only the insert is cooled. The inside can be heated and cooled quickly.
Accordingly, it is possible to contribute to energy saving, shorten the molding cycle, and reduce the running cost.

In addition, since a cavity temperature measuring means is provided in the vicinity of the molding cavity of the insert, the temperature in the molding cavity and the temperature of the molten resin filled in the molding cavity are indirectly measured. There is no need to use it, and a relatively inexpensive thermocouple, resistance thermometer, etc. can be used, and the initial cost can be reduced.
When the temperature in the molding cavity measured by the cavity temperature measuring means falls below a predetermined lower limit temperature, the insert is heated, and the temperature in the molding cavity measured by the cavity temperature measuring means exceeds the predetermined upper limit temperature. Since the nest is cooled at the time, heating and cooling can be switched at the most appropriate timing.

  In this way, by controlling the mold temperature only around the required cavity while reducing equipment costs, it is possible to reliably prevent the occurrence of weld lines and transfer defects, and to obtain a precise resin molded product, The mold unit for resin molding can reduce the initial cost and the running cost.

  In the mold unit for resin molding according to claim 2, since the cavity temperature measuring means is a thermocouple or a resistance temperature detector, in addition to the effect of the invention according to claim 1, in recent years, it is equivalent to an infrared temperature sensor. Since a thermocouple and a resistance temperature detector having a level temperature measurement speed (100 msec unit) can be obtained at a lower price than an infrared temperature sensor, the initial cost can be more reliably reduced.

  According to a third aspect of the present invention, there is provided a mold unit for resin molding comprising one or two or more inserts for forming a mold cavity provided in the resin mold and a temperature control medium provided only in the insert. Heat insulation means for insulating between the medium passage and the mold for resin molding excluding the insert, heating / circulation means for heating and circulating the temperature control medium, and cooling the temperature control medium The cooling / circulation means for circulation, the heating medium pipe for connecting the medium passage and the heating / circulation means, the cooling medium pipe for connecting the medium passage and the cooling / circulation means, and the resin mold are opened. A mold opening detecting means for detecting this and outputting a mold opening signal; a cavity filling detecting means for detecting that the molding cavity is filled with molten resin and outputting a cavity filling signal; and a mold opening detecting means from the mold opening detecting means. Cooling when signal is output The flow of the cooled medium from the ring means is interrupted, the heated medium is flowed from the heating / circulation means to the medium passage, and when the cavity filling signal is output from the cavity filling detection means, the heating / circulation means is heated. The heating / circulation means and the control means for controlling the cooling / circulation means so as to interrupt the flow of the medium and flow the cooled medium from the cooling / circulation means to the medium passage.

In this way, a medium passage for passing the temperature control medium is provided only in the nest that is insulated from the surroundings, and the medium heated by the heating / circulation means is passed through the medium passage via the heating medium pipe. Since only the child is heated and the medium cooled by the cooling / circulation means is passed through the medium passage through the cooling medium pipe and only the nest is cooled, the heat energy is used extremely efficiently, and the molding cavity The inside can be heated and cooled quickly.
Accordingly, it is possible to contribute to energy saving, shorten the molding cycle, and reduce the running cost.

In addition, a mold opening detecting means for detecting that the mold for resin molding has been opened and a cavity filling detecting means for detecting that the molding cavity has been filled with molten resin are provided, and a mold opening signal from the mold opening detecting means is provided. Is output, and the insert is cooled when a cavity filling signal is output from the cavity filling detection means. Therefore, heating and cooling can be switched at the most appropriate timing.
A contact sensor or proximity sensor can be used as the mold opening detection means, and a pressure sensor, a thermocouple, a resistance temperature detector, or the like can be used as the cavity filling detection means. Since it is inexpensive, the initial cost can be reduced.

  In this way, by controlling the mold temperature only around the required cavity while reducing equipment costs, it is possible to reliably prevent the occurrence of weld lines and transfer defects, and to obtain a precise resin molded product, The mold unit for resin molding can reduce the initial cost and the running cost.

  In the resin molding die unit according to claim 4, the medium heated by the heating / circulation means and the medium cooled by the cooling / circulation means are made of the same substance and enter through the medium passage. Switching means for flowing the medium coming out of the child to either heating / circulation means or cooling / circulation means, and medium temperature measurement for measuring the temperature of the medium passing through the medium passage and coming out of the child If the temperature of the medium measured by the means and the medium temperature measuring means is equal to or higher than the predetermined temperature, the medium is passed through the heating / circulating means, and if the temperature of the medium measured by the temperature measuring means is lower than the predetermined temperature, the medium is cooled. A switching control means for controlling the switching means so as to flow to the circulation means.

  Therefore, since the medium having a temperature equal to or higher than the predetermined temperature is flowed to the heating / circulation means, and the medium having a temperature lower than the predetermined temperature is flowed to the cooling / circulation means, in addition to the effects of the inventions according to claims 1 to 3, Both the energy required for heating in the circulation means and the energy required for cooling in the cooling / circulation means can be saved, and further energy saving can be achieved. Cost can be reduced.

In the mold unit for resin molding according to claim 5, since the predetermined temperature is the softening temperature or glass transition temperature of the synthetic resin, in addition to the effect of the invention according to claim 4, the resin mold enters through the medium passage. The medium coming out of the child can be more appropriately distributed to the heating / circulation means and the cooling / circulation means, and further energy saving can be achieved.
Some synthetic resins have a softening temperature that is not clearly defined. In this case, the glass transition temperature is set to a predetermined temperature instead of the softening temperature.

  In the mold unit for resin molding according to claim 6, the mold for resin molding has a gate cavity for guiding the molten resin to the molding cavity, and is provided in a portion away from the gate cavity of the molding cavity. A gas vent comprising a cylinder part provided in a mold, a piston part slidably fitted in the cylinder part, and a closing member formed integrally with the piston part and constituting a part of a molding cavity. The cylinder portion communicates with the outside of the mold for resin molding, and the gas vent is opened when the tip of the molten resin passes through the gate cavity. Is closed by sliding the closing member.

  As a result, this gas vent is closed by sliding the closing member by pressing the distal end portion of the closing member with the pressure of the molten resin, so that no control device or drive mechanism is required to close the gas vent, It can be configured simply and at low cost. In addition, since the front end portion of the closing member is pressed and closed by the pressure at the front end portion of the molten resin, the molten resin does not enter between the closing member and the cylinder portion, and the inside of the molding cavity After the air and the gas generated from the molten resin are sufficiently vented, the gas vent is closed.

  Therefore, in addition to the effects of the inventions according to the first to fifth aspects, so-called high-speed molding is possible in which the molten resin is fed into the molding cavity at a higher speed, and the occurrence of molding defects such as weld lines is more reliably generated. This can be prevented and the molding cycle can be further shortened, and the running cost can be further reduced.

  According to a seventh aspect of the present invention, there is provided a method for controlling a temperature of a resin molding die, wherein the resin molding die is provided with a nest for forming a molding cavity, and the medium for temperature control is passed only through the nest. A passage is provided to insulate between the insert and the resin mold except for the insert, and when the temperature in the molding cavity is indirectly measured and the temperature in the molding cavity falls below a predetermined lower limit temperature, the medium Stop the flow of the low-temperature cooling medium through the passage, flow the high-temperature heating medium through the medium passage, and stop the flow of the high-temperature heating medium through the medium passage when the temperature in the molding cavity exceeds a predetermined upper limit temperature. A low-temperature cooling medium is caused to flow through the medium passage, and a high-temperature heating medium and a low-temperature heating medium are alternately caused to flow through the medium passage.

In this way, a medium passage for passing a temperature control medium is provided only in the nest that is insulated from the surroundings, and a high-temperature heating medium is flowed through the medium path to heat only the nest, and the medium passage is cooled to a low temperature. Therefore, only the insert is cooled, so that the heat energy can be used very efficiently, and the inside of the molding cavity can be heated and cooled quickly.
Accordingly, it is possible to contribute to energy saving, shorten the molding cycle, and reduce the running cost.

In addition, the temperature inside the molding cavity and the temperature of the molten resin filled in the molding cavity are indirectly measured, so there is no need to use an expensive infrared sensor, and relatively inexpensive thermocouples and resistance thermometers are used. A body or the like can be used, and the initial cost can be reduced.
The insert is heated when the temperature inside the molding cavity falls below a predetermined lower limit temperature, and the insert is cooled when the temperature inside the molding cavity exceeds a predetermined upper limit temperature. And cooling can be switched.

  In this way, by controlling the mold temperature only around the required cavity while reducing equipment costs, it is possible to reliably prevent the occurrence of weld lines and transfer defects, and to obtain a precise resin molded product, This is a temperature control method for a resin molding die that can reduce both initial cost and running cost.

  The method for controlling the temperature of a resin molding die according to claim 8 is characterized in that the resin molding die is provided with a nest that forms a molding cavity, and the temperature controlling medium is passed only through the nest. A passage is provided to insulate between the mold and the resin mold except the insert, and when the resin mold is opened, the flow of a low-temperature cooling medium to the medium path is interrupted and the medium path is heated. When the molding cavity is filled with molten resin, the flow of the high-temperature heating medium is interrupted and the low-temperature cooling medium is supplied to the medium path, so that the high-temperature heating medium and the low-temperature heating medium are mixed. It is made to flow alternately in the medium passage.

In this way, a medium passage for passing a temperature control medium is provided only in the nest that is insulated from the surroundings, and a high-temperature heating medium is flowed through the medium path to heat only the nest, and the medium passage is cooled to a low temperature. Therefore, only the insert is cooled, so that the heat energy can be used very efficiently, and the inside of the molding cavity can be heated and cooled quickly.
Accordingly, it is possible to contribute to energy saving, shorten the molding cycle, and reduce the running cost.

Further, since the insert is heated when the resin molding die is opened and the insert cavity is cooled when the molding cavity is filled with the molten resin, heating and cooling can be switched at the most appropriate timing.
A contact sensor, a proximity sensor, or the like can be used as means for detecting that the resin molding die has been opened, and a pressure sensor or thermocouple can be used as means for detecting that the molding cavity is filled with molten resin. Since a resistance temperature detector or the like can be used, the initial cost can be reduced because it is less expensive than an infrared temperature sensor.

  In this way, by controlling the mold temperature only around the required cavity while reducing equipment costs, it is possible to reliably prevent the occurrence of weld lines and transfer defects, and to obtain a precise resin molded product, This is a temperature control method for a resin molding die that can reduce both initial cost and running cost.

  In the temperature control method for a resin molding die according to claim 9, the heating medium and the cooling medium are media made of the same material, and the medium connected to the medium passage outside the resin molding die is heated. The heating means and the cooling means for cooling the medium are arranged, the temperature of the medium passing through the medium passage and coming out of the insert is measured, and if the temperature is equal to or higher than a predetermined temperature, the medium is flowed to the heating means, If the temperature is lower than the predetermined temperature, the medium is passed through the cooling means.

  Therefore, the medium having a predetermined temperature or higher is caused to flow through the heating means, and the medium having a temperature lower than the predetermined temperature is caused to flow into the cooling means. Both the energy for heating and the energy for cooling required in the cooling means can be saved, energy can be further saved, and the running cost can be reduced.

In the method for controlling the temperature of the resin molding die according to claim 10, since the predetermined temperature is the softening temperature or glass transition temperature of the synthetic resin, in addition to the effect of the invention according to claim 9, it passes through the medium passage. Thus, the medium coming out of the insert can be more appropriately distributed to the heating means and the cooling means, and energy saving can be further achieved.
Some synthetic resins have a softening temperature that is not clearly defined. In this case, the glass transition temperature is set to a predetermined temperature instead of the softening temperature.

  In the temperature control method for a resin molding die according to claim 11, the resin molding die includes a gate cavity for guiding the molten resin to the molding cavity, and a gas vent provided in a portion of the molding cavity away from the gate cavity. The gas vent communicates with the outside of the resin molding die, and the gas vent is opened when the tip of the molten resin passes through the gate cavity and is closed by the pressure of the molten resin.

  As a result, since the gas vent is closed by the pressure of the molten resin, no controller or drive mechanism is required to close the gas vent, and the gas vent can be configured simply and at low cost. In addition, since it is pressed and closed by the pressure at the tip of the molten resin, the molten resin does not enter, and the air in the molding cavity and the gas generated from the molten resin are sufficiently vented. After being broken, the gas vent is closed.

  Therefore, in addition to the effects of the inventions according to claims 7 to 10, so-called high-speed molding is possible in which the molten resin is fed into the molding cavity at a higher speed, and the occurrence of molding defects such as weld lines is more reliably generated. This can be prevented and the molding cycle can be further shortened, and the running cost can be further reduced.

FIG. 1 is a schematic diagram showing the overall configuration of a resin molding die unit according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing the overall configuration of the control means of the resin molding die unit according to the first embodiment of the present invention. FIG. 3 is a flowchart of a control program executed by the control means of the resin molding die unit according to the first embodiment of the present invention. 4A is a perspective view showing a resin molded product (injection molded body) molded by the resin molding die unit according to Embodiment 1 of the present invention, FIG. 4B is a plan view, and FIG. 4C is a side view. It is. FIG. 5 is a longitudinal sectional view showing a longitudinal section in a state where the upper mold and the lower mold are closed in the resin molding mold of the resin molding mold unit according to the first embodiment of the present invention. FIG. 6 is a perspective perspective view showing shapes of the insert and the medium passage in the resin molding die of the resin molding die unit according to the first embodiment of the present invention. FIG. 7 is a perspective view showing a state in which the four inserts of FIG. 6 are combined. FIG. 8 is a partially enlarged longitudinal sectional view showing a state immediately after the injection molding is started in the molding cavity of the resin molding die unit according to the first embodiment of the present invention. FIG. 9 is a partially enlarged longitudinal sectional view showing a state at the time when injection molding is completed in the molding cavity of the resin molding die unit according to Embodiment 1 of the present invention. FIG. 10A is a partially enlarged longitudinal sectional view showing a gas vent portion immediately after the start of injection molding in the mold unit for resin molding according to Embodiment 1 of the present invention, and FIG. 10B is a time point when injection molding is completed. It is a partial expansion longitudinal cross-sectional view which shows the gas vent part. FIG. 11 is a schematic diagram showing an overall configuration of a resin molding die unit according to Embodiment 2 of the present invention. FIG. 12 is a flowchart of a control program executed in the switching control means of the resin molding die unit according to the second embodiment of the present invention. FIG. 13 is a schematic diagram showing the overall configuration of a resin molding die unit according to Embodiment 3 of the present invention. FIG. 14 is a flowchart of a control program executed by the control means of the resin molding die unit according to the third embodiment of the present invention.

The temperature control method of the resin molding die unit and the resin molding die according to the present invention is any resin molding method that obtains a resin molded product by allowing molten resin to flow into a molding cavity and solidify. It can be applied to various resin molding methods.
Examples of such resin molding methods include injection molding, transfer molding, blow molding (hollow molding), and compression molding. In particular, the application to the injection molding method is more preferable because the effect of reducing the initial cost and running cost appears clearly.
As described above, the synthetic resin includes so-called FRP (fiber reinforced plastic) in the present specification and claims, as described above. However, the ceramic particles and the synthetic resin are kneaded to perform injection molding or compression. Also for the method of molding the ceramic / synthetic resin mixed molded body by the molding method, the temperature control method of the resin molding die unit and the resin molding die according to the present invention can be applied.

  In order to carry out the temperature control method for the resin molding die unit and the resin molding die according to the present invention, the resin molding die is provided with an insert for forming a molding cavity, and the insert is It is necessary to insulate from.

  Generally, carbon steel for mechanical structures (S45C, S50C, S55C, etc.), chromium molybdenum steel (SCM4, etc.), carbon tool steel (SK7, etc.), etc. are used as the material for resin molding dies. Since more preciseness, friction resistance and the like are required as the material, it is more preferable to use die steel (SKD4, SKD5, SKD6, SKD61, etc.), high speed steel (SKH2, etc.).

  Further, as a means for insulating the nest from the surroundings, there is a method of providing a heat insulating material or a space. As the heat insulating material, fiber heat insulating materials such as glass wool, rock wool, wool heat insulating material and cellulose heat insulating material, foam heat insulating materials such as urethane foam, phenol foam, polystyrene foam, extruded polystyrene (XPS), vacuum heat insulating material, etc. There is.

  Furthermore, it is necessary to provide a medium passage for heating and cooling only the insert. The medium passage can be provided as a through hole so as not to communicate with the molding cavity inside the insert, and surrounds the outer periphery of the insert. Although it can be provided in the form of a pipe, it is preferably provided as a through hole inside the insert because the structure is simple and the efficiency of heating and cooling is good.

Here, in order to further improve the efficiency of heating and cooling, it is preferable to make the through-hole complicatedly meander in the nest so that the flow area volume of the medium passage is as large as possible.
As a method for forming such a complicated medium passage, for example, the lower half of the meandering passage is engraved on one side of a flat plate-shaped steel material, and the upper half of the meandering passage on one side of another flat plate-like steel material. There is a method of forming a medium passage as a through-hole meandering these steel plates together.
It is more preferable to develop this further and provide a through-hole in the vertical direction of the steel plate to form a three-dimensional meandering medium passage. For this purpose, it is necessary to form a nesting by superposing four or more steel plates.

  In order to carry out the present invention, a thermocouple or a resistance thermometer as a “cavity temperature measuring means” or “cavity filling detecting means” which is less expensive than an infrared temperature sensor and has the same response speed. Etc. are required. As such a thermocouple having a high response speed and a low price, PT-100 / 550UN manufactured by MYSEC Co., Ltd., T36S sheathed thermocouple manufactured by Nippon Denso Co., Ltd., and sheathed thermocouple manufactured by Yamazato Sangyo Co., Ltd. ( THERMIC) and Cerathermo Thermocouple, Seikei Keiki Co., Ltd. molding machine thermocouple SMT-13S, Tool House Co., Ltd. sheath thermocouple TCS series, Ambe SMT Co., Ltd. ultrafine thermocouple KFG series, etc. Can be used.

  In addition, as a resistance temperature detector having a high response speed and a low price, a sheath type resistance temperature detector Pt100Ω (JIS-C1606-1989), a platinum resistance temperature detector mica type, ceramic type, and capillary type made by Aoi Electric Heat Co., Ltd. Resistance thermometer (JIS-C1604-1997), sheathed resistance thermometer (RESIMIC) manufactured by Yamazato Sangyo Co., Ltd. and capillary tube resistance thermometer (RESISSIM), for chemical temperature measurement made by RTD A resistance temperature detector or the like can be used.

[Example 1]
Hereinafter, a temperature control method for a resin molding die unit and a resin molding die according to a first embodiment of the present invention will be described with reference to FIGS.

First, the overall configuration of the resin molding die unit according to the first embodiment of the present invention will be described with reference to the schematic diagram of FIG.
As shown in FIG. 1, in the resin molding die unit 1 according to the first embodiment, an injection molding die 2A as a pair of upper and lower resin molding dies made of carbon steel for machine structure (S45C). (Upper die), 2B (lower die) are provided with a pair of upper and lower inserts 3A, 3B made of die steel (SKD1), and a pair of upper and lower inserts 3A, 3B are closed to form a cavity. 5 is formed.

The insert 3A is provided with a medium passage 6A, and the insert 3B is provided with a medium passage 6B. These medium passages 6A and 6B are heated and heated via a heating medium pipe 8a and a cooling medium pipe 9a. It is connected to the circulation means 8 and the cooling / circulation means 9.
Here, each of the insert 3A and the insert 3B has only one medium passage 6A, 6B, and the heating medium pipe 8a and the cooling medium pipe 9a are joined together, and the heated medium and the cooled medium are combined. Are configured to flow through a common passage.
In Example 1, dibenzyltoluene (methylbis (phenylmethyl) benzene), also called Neo-SK Oil 1400, was used as a temperature control medium.

The heating / circulation means 8 includes a heater as a heating mechanism and a tank for storing a heated medium, a temperature control device for measuring the temperature of the heated medium to turn on and off the heater, and a heating stored in the tank as a circulation mechanism. It comprises a diaphragm pump that pumps the applied medium to the heating medium pipe 8a.
The cooling / circulation means 9 includes a chiller as a cooling mechanism and a tank for storing the cooled medium, a temperature control device for measuring the temperature of the cooled medium to turn on and off the chiller, and a cooling stored in the tank as the circulation mechanism. It is comprised from the diaphragm pump which pressure-feeds the made medium to the cooling medium piping 9a.

In the first embodiment, the lower mold 2B and the insert 3B are provided with the gas vent 11 and the exhaust hole 13 connected from the gas vent 11 to the outside of the lower mold 2B.
Further, in the first embodiment, a plurality of spaces 7 are provided as heat insulating means for insulating between the inserts 3A and 3B and the resin molding dies 2A and 2B excluding the inserts 3A and 3B. . Specifically, a plurality of grooves 7 are provided on the outer surfaces of the inserts 3A and 3B in contact with the inner surfaces of the resin molds 2A and 2B.

  FIG. 1 is a schematic diagram, and in FIG. 1, the molten resin MR is drawn from the right side surface of the injection molds 2A and 2B through the gate cavity 4, but actually, in FIG. As will be described, the injection molds 2A and 2B are multi-cavity molds having a plurality of molding cavities 5, and the injection nozzle of the injection molding machine is in contact with the upper surface of the upper mold 2A and the upper surface of the upper mold 2A. Molten resin MR flows in.

Further, a cavity temperature measuring means 10 is provided in the vicinity of the molding cavity 5. In the first embodiment, as the cavity temperature measuring means 10, a thermocouple (K type) having a high response speed (extra fine thermocouple KFG series manufactured by Ambe SMT Co., Ltd.) is used as shown in FIG. It installed in the vicinity of the shaping | molding cavity 5 of the child 3B.
Further, in the resin molding die unit 1 according to the first embodiment, the heating / circulation unit 8 and the cooling / circulation unit 9 are controlled according to the temperature in the molding cavity 5 measured by the cavity temperature measuring unit 10. Control means 12 is provided.

  As shown in the block diagram of FIG. 2, the control means 12 includes an input port 51 to which electrical signals output from the cavity temperature measurement means 10, the heating / circulation means 8, and the cooling / circulation means 9 are input, and an analog signal. An A / D converter 52 that converts a certain electrical signal into a digital signal, a central processing unit (CPU) 54, a calculation unit 53 that includes a microprocessor having a memory device, and a digital signal that is converted into an electrical signal that is an analog signal. The computer system includes a D / A converter 58 and an output port 59 that outputs an electrical signal.

The calculation unit 53 including a microprocessor includes a CPU 54 that performs calculation and control, a RAM 55 that is used as a working memory when the CPU 54 performs various calculation processes, a ROM 56 that stores a control program, a timer 57, and the like. As the RAM 55 and ROM 56, a semiconductor memory, a magnetic core, or the like is used. As the CPU 54 that performs calculation and control, a CPU having a calculation function such as an MPU can be used.
Various programs are stored in the ROM 56, and various data are stored in the RAM 55. When the ROM 56 is an EEPROM, programs and data are read from an external storage device and written to the ROM 56. Is possible.

The analog signal of the temperature measured by the thermocouple as the cavity temperature measuring means 10 is input to the input port 51 of the control means 12 by electric wiring, converted into a digital signal by the A / D converter 52, and the arithmetic unit 53. Are compared with predetermined lower limit temperature and upper limit temperature according to the control program stored in the ROM 56, and a digital signal indicating the calculation result is converted into an analog signal by the D / A converter 58 and output from the output port 59. The heating / circulation means 8 and the cooling / circulation means 9 are controlled.
In addition, from the heating / circulation means 8 and the cooling / circulation means 9, an operation signal is input to the input port 51 of the control means 12 when the respective heating mechanism and cooling mechanism are operating.

  In the resin molding die unit 1 according to the first embodiment having such a configuration, the temperature control method of the resin molding dies 2A and 2B executed in accordance with the control program stored in the ROM 56 will be described with reference to FIGS. This will be described with reference to the flowcharts of FIGS.

First, when the injection molding is started, the injection molding machine is turned on, and the heating mechanism and cooling mechanism operating switches of the heating / circulation means 8 and the cooling / circulation means 9 are turned on (the injection molding is completed). In some cases, the heating and cooling mechanisms are switched off). As a result, the resin molding die unit 1 is operated, and control is started in step S1 of the flowchart of FIG. 3. In step S2, whether or not injection molding is in progress, that is, the heating mechanism and cooling It is determined whether or not the cooling mechanism of the circulation means 9 is operating.
Specifically, it is determined whether or not an operation signal is input to the control means 12 from the heating / circulation means 8 and the cooling / circulation means 9. If not during injection molding, the heating / circulation means 8 and the cooling / circulation means 9 are completely stopped in step S7, and the control is terminated in step S8.
As a method of determining whether or not the injection molding is in progress, a method of determining whether or not the power of the injection molding machine is turned on is also conceivable, but there is a drawback that the wiring must be taken out from the injection molding machine.

On the other hand, if injection molding is in progress, it is determined in step S3 whether or not the temperature in the molding cavity 5 is below a predetermined lower limit temperature. That is, when the upper mold 2 </ b> A and the lower mold 2 </ b> B are closed and the inside of the molding cavity 5 is empty, an electric signal of the measured temperature is output from the thermocouple as the cavity temperature measuring unit 10 and input to the control unit 12.
At this time, since the temperature in the molding cavity 5 is below the predetermined lower limit temperature (100 ° C.), the process proceeds from step S3 to step S4, and the control unit 12 operates the circulation mechanism of the heating / circulation unit 8. The dibenzyltoluene as a medium heated to 280 ° C. is caused to flow from the heating / circulation means 8 to the medium passages 6A and 6B through the heating medium pipe 8a.

Then, it is determined whether or not injection molding is being performed again in step S2, and if injection molding is being performed, it is determined again whether or not the temperature in the molding cavity 5 is below a predetermined lower limit temperature in step S3. If dibenzyltoluene heated to 280 ° C. is caused to flow through the medium passages 6A and 6B, and the temperature in the molding cavity 5 reaches a predetermined lower limit temperature of 100 ° C. or more, the process proceeds from step S3 to step S5, and molding is performed. It is determined whether or not the measured temperature in the cavity 5 exceeds a predetermined upper limit temperature (300 ° C.).
Until the injection molding is performed, the measured temperature in the molding cavity 5 does not exceed the predetermined upper limit temperature of 300 ° C., so the process returns from step S5 to step S2 to heat the upper mold 2A and the lower mold 2B. Will continue.

On the other hand, in parallel with this, the upper die 2A and the lower die 2B are closed to form a molding cavity 5, and polyether ether ketone (hereinafter referred to as a molten resin MR) heated and melted to 400 ° C. from an unillustrated injection molding machine. , Also referred to as “PEEK”) (melting point 334 ° C.) flows into the molding cavity 5 through the gate cavity 4 and is filled.
As a result, the measured temperature in the molding cavity 5 output from the thermocouple serving as the cavity temperature measuring means 10 exceeds a predetermined upper limit temperature of 300 ° C., so that the process proceeds from step S5 to step S6. A signal for stopping the circulation mechanism of the circulation means 8 and operating the circulation mechanism of the cooling / circulation means 9 is output, the flow of dibenzyltoluene heated to 280 ° C. is stopped, and the cooling / circulation means 9 through the cooling medium pipe 9a, dibenzyltoluene as a medium cooled to 50 ° C. is caused to flow into the medium passages 6A and 6B.

  Then, when the molten resin MR filled in the molding cavity 5 is solidified by dibenzyltoluene as a medium cooled to 50 ° C. and falls below a predetermined lower limit temperature of 100 ° C., steps S3 to S3 are performed. Proceeding to S4, the control means 12 outputs a signal for stopping the circulation mechanism of the cooling / circulation means 9 and operating the circulation mechanism of the heating / circulation means 8, and the dibenzyltoluene cooled to 50 ° C. While the flow is stopped, dibenzyltoluene as a medium heated to 280 ° C. is caused to flow from the heating / circulation means 8 to the medium passages 6A and 6B through the heating medium pipe 8a.

The resin molded body in which the molten resin MR filled in the molding cavity 5 is solidified is opened from the molding cavity 5 by opening the upper mold 2A and the lower mold 2B during the cooling process or at the end of the cooling process. It is taken out. When the resin molded body is taken out in the middle of the cooling process in which the resin molded body is cooled to 100 ° C. or lower, the molding cavity 5 is empty at that time and rapidly cooled to 100 ° C. or lower. Therefore, since the process proceeds from step S3 to step S4, the molding cycle is shortened as the resin molded body is taken out earlier.
Further, since the resin molding dies 2A and 2B according to the first embodiment are provided with the gas vent 11, it is possible to perform high-speed molding in which the molten resin MR is filled at high speed, thereby further reducing the molding cycle. Is done.

  In these series of steps, after the injection molding is completed, the heating mechanism of the heating / circulation means 8 and the cooling mechanism of the cooling / circulation means 9 stop operating, and the process proceeds from step S2 to step S7. Then, the cooling / circulation unit 9 is completely stopped, and the process is repeated until the control is finished in step S8.

Thus, by repeating these steps according to the flowchart shown in FIG. 3, in the temperature control method of the resin molding die unit 1 and the resin molding dies 2A and 2B according to the first embodiment, In this way, heating / cooling of only the inserts 3A and 3B is repeated, so-called heat cycle molding is carried out, and even if PEEK, which is a super engineering plastic, is used as a synthetic resin, the occurrence of weld lines, transfer defects, etc. Precise prevention and precise resin molding can be obtained.
Moreover, since only the inserts 3A and 3B are heated and cooled, energy saving can be achieved, and furthermore, a cheap thermocouple is used as a means for determining the timing for switching between heating and cooling. , Equipment costs can be reduced.

Next, a resin molded product molded by the resin molding dies 2A and 2B of the resin molding die unit 1 according to the first embodiment will be described with reference to FIG. As shown in FIG. 4A, the resin molded product W1 molded by the resin molding dies 2A and 2B according to the first embodiment is made of a resin that is held by a human hand when opening and closing the automobile door. Is the handle.
The thickness of the thinnest portion W1c of the resin molded product W1 shown in FIG. 4C is 2 mm, which can be said to be a thin resin molded product. In addition, as described above, in Example 1, the resin molded product W1 is injection-molded with polyether ether ketone (PEEK), which is a synthetic resin having a high melting point, and in order not to cause molding defects, as described above. It is necessary to carry out heat cycle molding.

  In the resin molding molds 2A and 2B of the resin molding mold unit 1 according to the first embodiment, a plurality of handles W1 as such resin molded products are molded at a time, and As shown in FIGS. 4B and 4C, the gate is provided on the attachment side W1a of the handle W1 and molded. Therefore, a gas vent is provided at the other end W1b of the handle W1 that is farthest from the gate W1a.

Next, the overall configuration of the resin molding dies 2A and 2B in the resin molding die unit 1 according to the first embodiment will be described with reference to the longitudinal sectional view of FIG. In FIG. 5, the medium passage is not shown in order to make the drawing easier to see.
As shown in FIG. 5, the molds 2A and 2B for resin molding according to the first embodiment are configured by an upper mold 2A and a lower mold 2B as a pair of molds, and the upper mold 2A is injection molded. The lower mold 2B is a movable mold that is fixed to the raising / lowering portion of the injection molding machine. By closing the upper mold 2A and the lower mold 2B, a plurality of pairs of molding cavities 5A and 5B corresponding to the shape of the resin molded product W1 are formed between them in the vertical direction of the drawing.

  That is, the resin molding molds 2A and 2B of the resin molding mold unit 1 according to the first embodiment produce an even number of resin molded products W1 simultaneously by one injection molding (multiple molding) resin molding. It is a metal mold. By closing the upper mold 2A and the lower mold 2B, at the same time, in the state where the lower end of the injection molding machine (the tip of the resin injection nozzle) is in close contact with the upper end 18 of the sprue bushing 19, the molten resin injected from the resin injection nozzle 2 A gate cavity 4 is also formed to lead to the two molding cavities 5A and 5B.

  Nests 3AA and 3AB provided with a part of these gate cavities 4 and wall surfaces on the upper surfaces of the molding cavities 5A and 5B are fixed to the upper mold 2A, and these gate cavities are fixed to the lower mold 2B. The inserts 3BA and 3BB provided with a part of 4 and a wall surface on the lower surface side of the molding cavities 5A and 5B are fixed. Further, the lower mold 2B is provided with a bottom plate 2Ba, and a total of seven ejector pins 20 are fixed to the bottom plate 2Ba so as to be movable up and down integrally with the bottom plate 2Ba.

  The nests 3BA and 3BB are provided with gas vents 11A and 11B in contact with the wall surfaces on the lower surface side of the molding cavities 5A and 5B, and these gas vents 11A and 11B are provided through the exhaust holes 13A and 13B. , It communicates with the outside of the lower mold 2B. Due to these gas vents 11A and 11B, the gas generated from the air and molten resin in the molding cavities 5A and 5B is surely vented during injection molding, and a molding defect such as a short shot or a weld line may occur. Surely prevented.

Next, FIG. 6 shows the structures of the inserts 3AB and 3BB located on the right side in FIG. 5 and the medium passages in the resin molding dies 2A and 2B of the resin molding die unit 1 according to the first embodiment. The description will be given with reference. FIG. 6 is a perspective perspective view in which the inserts 3AB and 3BB are taken out, the outlines of the inserts 3AB and 3BB are indicated by two-dot chain lines, and the medium passage is indicated by a solid line. The configurations of the inserts 3AA and 3BA and the medium passage located on the left side in FIG. 5 are the same.
As shown in FIG. 6, the upper insert 3AB is unitary (provided that the four steel plates are stacked), but the lower insert 3BB further includes the insert 3BBa and the insert 3BBb. And it is divided into three of the telescopic base 3BBc.

  As shown in FIG. 6, medium paths 6AB, 6BBa, and 6BBb that are much more complicated than the medium paths 6A and 6B schematically shown in FIG. 1 are formed in the inserts 3AB, 3BBa, and 3BBb. Has been. These medium passages 6AB, 6BBa, 6BBb meander finely, the medium passage 6AB has a two-stage structure, and the medium passages 6BBa, 6BBb have a three-stage structure.

In other words, the medium path 6AB is formed by superposing four steel plates in which the upper half or the lower half of the medium path 6AB is engraved on one side or both sides, and the medium paths 6BBa, 6BBb are formed on one side or both sides of the medium paths 6BBa, 6BBb. It is formed by superposing six steel plates engraved with the upper half or the lower half.
Note that cooling water always flows through the thick linear passage 6BBc provided in the telescopic base 3BBc.

Then, as shown in FIG. 7, the lower nesting 3BB is formed by fitting the symmetric nesting 3BBa and the nesting 3BBb into the nesting base 3BBc, and the lower nesting 3BB is located on the upper side. The molding cavity 5B is formed by overlapping the inserts 3AB. The molding cavity 5A shown on the left side of FIG. 5 is formed in exactly the same manner.
Further, as shown in FIG. 7, a plurality of grooves 7 for forming a heat insulation space as a heat insulation means are provided on the outer peripheral surfaces of the upper insert 3AB and the lower insert 3BB. .

  In the resin molding die unit 1 according to the first embodiment having such a configuration, the resin injection nozzle melts from the resin injection nozzle in a state where the tip of the resin injection nozzle (not shown) is in close contact with the upper end 18 of the sprue bush 19 shown in FIG. When the resin is injected, as shown in FIG. 9, the resin sprue P1 in which the resin is filled in the sprue bush 19, the resin runner P2 in which the gate cavity 4 is filled with resin, and the molding cavity 5A are filled with resin. The formed resin molded product W1 is integrally formed of synthetic resin.

  As shown in FIGS. 8 and 9, the lower mold 2B of the resin molding die unit 1 according to the first embodiment is in contact with the end opposite to the resin runner P2 of the resin molded product W1. A gas vent 11A is provided. As described above, the resin molding die unit 1 is a resin molding die unit for producing an even number of resin molded products W1 at the same time by a single injection molding (multi-piece), and the lower mold 2B. A plurality of pairs of mold cavities 5A and 5B (5C, 5D,...) Are provided.

  Next, the detailed structure of the resin molding die unit 1 according to the first embodiment and the operation of each part during injection molding will be described with reference to FIGS. In the resin molding dies 2A and 2B according to the first embodiment, as shown in FIG. 8, which is a partial longitudinal sectional view showing a state immediately after PEEK as a synthetic resin is injection-molded, the tip portion of the molten resin Since the gas vent 11A is open until P3 flows in while forming the resin sprue P1 and the resin runner P2 and reaches the front surface of the closing member 14A, the gas generated from the air in the molding cavity 5A and the molten resin Is extruded from the gas vent 11A to the outside of the resin molding die 2B through the exhaust hole 13A.

  Thereafter, as shown in FIG. 9, when the front surface of the closing member 14A is pressed by the tip portion P3 of the molten resin, the closing member 14A slides and comes into close contact with the cylinder portion 15A. By sliding the closing member 14A against the urging force of the spring member 16A in this manner, as shown in FIG. 9, the gas vent 11A is securely closed before the front end portion P3 of the molten resin material arrives. Thus, the resin molded product W1 is manufactured.

  Next, the dimensions of each part constituting the gas vent 11A in the resin molding die unit 1 according to the first embodiment will be described with reference to FIG.

  8 and 9, for convenience of explanation, the interval between the closing member 14A of the gas vent 11A and the cylinder portion 15A at the time of injection molding is greatly exaggerated, but in practice, it is shown in FIG. 10 (a). As shown in the figure, the distance between the tip portion 14Ab of the closing member 14A and the cylinder portion 15A is only 0.15 mm, and before the tip portion P3 of the molten resin arrives, from the gap of 0.15 mm inside the molding cavity 5A. The gas generated from the air and the molten resin is discharged as shown by the arrows and degassed.

  When the front surface of the distal end portion 14Ab of the closing member 14A is pressed by the distal end portion P3 of the molten resin, the closing member 14A slides 0.3 mm against the biasing force of the spring member 16A, and FIG. As shown in FIG. 4, the tip portion 14Ab is in close contact with the cylinder portion 15A. Thereby, before the front end portion P3 of the molten resin material reaches, the gas vent 11A is securely closed, and the resin molded product W1 is injection-molded.

  Here, as shown in FIG. 10B, the front end portion 14Ab of the closing member 14A protrudes downward at an angle of 30 degrees, and as shown in FIG. 10A, the front end portion P3 of the molten resin. Flows from above, a gap having an interval of 0.15 mm is formed on the back side of the tip portion P3 of the molten resin. Therefore, the gas vent 11A can be reliably closed before the front end portion P3 of the molten resin enters and enters the 0.15 mm gap.

  Thus, as an effect unique to the first embodiment, in the resin molding die unit 1 according to the first embodiment, the front end portion P3 of the molten resin flows into the gas venting gap of the gas vent 11A. Since it is provided in the back side of the coming side, the effect that the gas vent 11A can be reliably closed before the front end portion P3 of the molten resin enters the gap of the gas vent 11A is obtained.

  As described above, in the resin molding die unit 1 and the resin molding die temperature control method according to the first embodiment, the molding cavity 5 (5A, 5B,...) Medium passages 6A and 6B are provided in the nested upper mold 3A (3AA, 3AB,...) And the nested lower mold 3B (3BA, 3BB,...) To insulate the nested upper mold 3A and the nested lower mold 3B. By controlling the mold temperature only around the required molding cavity 5 by insulating from the surroundings in the space 7, it is possible to reliably prevent the occurrence of weld lines and transfer defects, and to obtain a precise resin molded product. Running costs can also be reduced.

  Further, as the cavity temperature measuring means 10, a thermoelectric device that is cheaper and has a faster response speed than an infrared temperature sensor (for example, Futaba Electronics Co., Ltd. resin temperature sensor EPSSSZL series: 134,400 yen to 165,900 yen). Since the ultra-fine thermocouple KFG series (3000 yen to 13,600 yen) manufactured by Ambe SMT Co., Ltd. is used as the pair (K type), the equipment cost can be reduced.

When the temperature in the molding cavity 5 measured by the thermocouple falls below a predetermined lower limit temperature of 100 ° C., dibenzyl toluene as a medium heated to 280 ° C. is caused to flow through the medium passages 6A and 6B, and the measurement is performed. When the temperature inside the molded cavity 5 exceeds 300 ° C., which is a predetermined upper limit temperature, the flow of dibenzyltoluene as a medium heated to 280 ° C. is interrupted, and the medium cooled to 50 ° C. Of dibenzyltoluene and so-called heat cycle molding.
As a result, even if PEEK, which is a super engineering plastic, is used as a synthetic resin, it is possible to reliably prevent the occurrence of weld lines, transfer defects, and the like and obtain a precise resin molded product.

In the first embodiment, the predetermined lower limit temperature is set to 100 ° C. and the predetermined upper limit temperature is set to 300 ° C. Usually, PEEK (melting point: 334 ° C.) raises the temperature of the injection nozzle of the injection molding machine to about 400 ° C. When the molding cavity 5 takes a long time to heat and cool in the molding cavity 5 because it is raised and injection molded, the predetermined lower limit temperature is set to about 100 ° C. to 150 ° C., and the predetermined upper limit temperature is set to 310 ° C. It is good also as about -350 degreeC.
Since PEEK is solidified to such an extent that the resin temperature can be sufficiently removed when the resin temperature is lowered to about 200 ° C., there is no problem even if the predetermined lower limit temperature is about 100 ° C. to 150 ° C., and further about 150 ° C. to 200 ° C.

  In this way, in the resin molding die unit 1 and the resin molding die temperature control method according to the first embodiment, the equipment cost is controlled and the mold temperature only around the cavity is required. As a result, it is possible to reliably prevent the occurrence of weld lines and transfer defects and to obtain a precise resin molded product, and to reduce the initial cost and the running cost.

[Example 2]
Next, the entire structure of the resin molding die unit and the temperature control method of the resin molding die according to the second embodiment of the present invention will be described with reference to the schematic diagram of FIG. 11 and the flowchart of FIG.

  As shown in FIG. 11, in the resin molding die unit 21 according to the second embodiment, a pair of upper and lower resin molding dies made of carbon steel for mechanical structure (S45C), as in the first embodiment. A pair of upper and lower inserts 3A and 3B made of die steel (SKD1) are provided inside injection molds 2A (upper mold) and 2B (lower mold) as molds, and a pair of upper and lower inserts 3A and 3A, The molding cavity 5 is formed by closing 3B.

The insert 3A is provided with a medium passage 6A, and the insert 3B is provided with a medium passage 6B. These medium passages 6A and 6B are heated and heated via a heating medium pipe 28a and a cooling medium pipe 29a. It is connected to the circulation means 28 and the cooling / circulation means 29.
Here, each of the insert 3A and the insert 3B has only one medium passage 6A, 6B, and the heating medium pipe 28a and the cooling medium pipe 29a are joined together, and the heated medium and the cooled medium are combined. Are configured to flow through a common passage.
Also in Example 2, dibenzyltoluene was used as a temperature control medium.

Also in the second embodiment, the lower mold 2B and the insert 3B are provided with the gas vent 11 and the exhaust hole 13 connected from the gas vent 11 to the outside of the lower mold 2B.
Furthermore, also in the second embodiment, a plurality of spaces 7 are provided as heat insulating means for insulating between the inserts 3A and 3B and the resin molding dies 2A and 2B excluding the inserts 3A and 3B. . Specifically, a plurality of grooves 7 are provided on the outer surfaces of the inserts 3A and 3B in contact with the inner surfaces of the resin molds 2A and 2B.

Further, a cavity temperature measuring means 10 is provided in the vicinity of the molding cavity 5. Also in the second embodiment, as the cavity temperature measuring means 10, a thermocouple (K type) having a high response speed (extrafine thermocouple KFG series manufactured by Ambe SMT Co., Ltd.) is used as shown in FIG. It installed in the vicinity of the shaping | molding cavity 5 of the child 3B.
Further, in the resin molding die unit 21 according to the second embodiment, the heating / circulation means 28 and the cooling / circulation means 29 are controlled according to the temperature in the molding cavity 5 measured by the cavity temperature measurement means 10. Control means 12 is provided.

The heating / circulation means 28 includes a heater as a heating mechanism and a tank for storing a heated medium, a temperature control device for measuring the temperature of the heated medium to turn on and off the heater, and heating stored in the tank as a circulation mechanism. The diaphragm is configured to be a diaphragm pump that pumps the medium to the heating medium pipe 28a.
The cooling / circulation means 29 includes a chiller as a cooling mechanism, a tank for storing a cooled medium, a temperature control device for measuring the temperature of the cooled medium to turn on and off the chiller, and a cooling stored in the tank as a circulation mechanism. The diaphragm is configured to be a diaphragm pump that pumps the medium to the cooling medium pipe 29a.

  FIG. 11 is a schematic diagram. In FIG. 11, the molten resin MR is drawn from the right side surface of the injection molds 2A and 2B through the gate cavity 4, but in reality, the injection mold is used. The molds 2A and 2B are multi-cavity molds having a plurality of molding cavities 5. The injection nozzle of the injection molding machine is in contact with the upper surface of the upper mold 2A, and the molten resin MR flows from the upper surface of the upper mold 2A.

The resin molding die unit 21 according to the second embodiment is different from the resin molding die unit 1 according to the first embodiment in that the medium returning through the medium passage 6A and the medium passage 6B is switched. The three-way solenoid valve 23 as a means is three-way from the point where it flows to either the heating / circulation means 28 or the cooling / circulation means 29 and the position where the medium returning through the medium passage 6A and the medium passage 6B joins. The medium temperature measuring means 22 is provided in the medium pipe on the electromagnetic valve 23 side.
As the medium temperature measuring means 22, in Example 2, the sheath thermocouple TCS series manufactured by Tool House Co., Ltd. was used, and the temperature of the medium was directly measured by being inserted into the medium pipe.

Furthermore, switching control means 24 is provided for receiving a measurement signal from the medium temperature measuring means 22 and controlling a three-way electromagnetic valve 23 as switching means.
Similarly to the control unit 12, the switching control unit 24 also has an input port for receiving an electrical signal output from the medium temperature measurement unit 22, an A / D converter that converts the electrical signal into a digital signal, and a central processing unit ( (CPU) and a computing unit having a memory device, a D / A converter that converts a digital signal into an analog signal, and an output port that outputs an analog signal.
The heating / circulation means 28 and the cooling / circulation means 29 input operation signals to the input ports of the control means 12 and the switching control means 24 when the respective heating mechanisms and cooling mechanisms are operating. .

A temperature control method in the resin molding die unit 21 according to the second embodiment having such a configuration will be described with reference to the flowcharts of FIGS. 11 and 12.
The mold temperature control method is the same as that in the flowchart of FIG. However, unlike Example 1, as a synthetic resin, polycarbonate (melting point: 220 ° C. to 230 ° C.) is used, and a polycarbonate as a molten resin MR melted at 300 ° C. is flowed from an injection molding machine (not shown) and heated. From the circulation means 28, dibenzyltoluene as a medium heated to 200 ° C. flows through the medium passages 6A and 6B through the heating medium pipe 28a. The predetermined lower limit temperature is set to 100 ° C., and the predetermined upper limit temperature is set to 210 ° C.

Furthermore, the difference from the first embodiment is that the medium temperature measured by the sheath thermocouple as the medium temperature measuring means 22 is parallel to the heating and cooling of the inserts 3A and 3B by the dibenzyltoluene as the medium. The three-way electromagnetic valve 23 as the switching means is controlled depending on whether or not the electric signal is input to the switching control means 24 and the glass transition temperature of polycarbonate as a predetermined temperature is 150 ° C. or higher.
Since the softening temperature of polycarbonate is not clearly defined, the glass transition temperature is used as the predetermined temperature.

That is, as shown in the flowchart of FIG. 12, the resin molding die unit 21 starts operating, and the switching control by the switching control means 24 is started in step S11. First, in step S12, whether or not injection molding is in progress. That is, it is determined whether the heating mechanism of the heating / circulation means 28 and the cooling mechanism of the cooling / circulation means 29 are operating. If injection molding has not been performed, the process proceeds to step S16, and the switching control ends.
If injection molding is in progress, the process proceeds to step S13, where it is determined whether the medium temperature measured by the sheath thermocouple 22 is equal to or higher than a predetermined temperature of 150 ° C. When the medium temperature measured by the sheath thermocouple 22 is 150 ° C. or higher, the process proceeds to step S14, where the three-way solenoid valve 23 is switched to flow the medium to the heating / circulation means 28, and the medium temperature is a predetermined temperature. If the temperature is lower than 150 ° C., the process proceeds to step S 15, and the three-way solenoid valve 23 is switched to flow the medium to the cooling / circulation means 29.

As a result, when dibenzyltoluene as a medium is hot, it is returned to the heating / circulation means 28, and when it is cold, it is returned to the cooling / circulation means 29. Therefore, the heating / circulation means 28 and the cooling / circulation means 29 are heated. -The heat energy consumed for cooling is saved, and further energy saving can be achieved.
Such switching control is repeated until it is determined in step S12 that the injection molding is not being performed, and the process proceeds to step S16 to complete the switching control.

  Thus, in the resin molding die unit 21 and the resin molding die temperature control method according to the second embodiment, the equipment cost is suppressed and the mold temperature only around the cavity is required. As a result, it is possible to reliably prevent the occurrence of weld lines and transfer defects and to obtain a precise resin molded product, and to reduce the initial cost and the running cost.

[Example 3]
Next, the overall structure of the resin molding die unit and the temperature control method of the resin molding die according to Example 3 of the present invention will be described with reference to the schematic diagram of FIG. 13 and the flowchart of FIG.

  As shown in FIG. 13, in the resin molding die unit 31 according to the third embodiment, an injection molding die 32A as a pair of upper and lower resin molding dies made of carbon steel for machine structure (S45C). (Upper mold) and 32B (lower mold) are provided with a pair of upper and lower inserts 33A and 33B made of die steel (SKD1), and a pair of upper and lower inserts 33A and 33B are closed to form a cavity. 35 is formed.

The heating / circulation means 38 includes a heater as a heating mechanism and a tank for storing the heated medium, a temperature control device for measuring the temperature of the heated medium to turn on and off the heater, and a heating stored in the tank as the circulation mechanism. The diaphragm is configured to be a diaphragm pump that pumps the medium to the heating medium pipe 38a.
The cooling / circulation means 39 includes a chiller as a cooling mechanism and a tank for storing the cooled medium, a temperature control device for measuring the temperature of the cooled medium to turn the chiller on and off, and a cooling stored in the tank as the circulation mechanism. The diaphragm is configured to be a diaphragm pump that pumps the medium to the cooling medium pipe 39a.

  Here, the difference from the resin molding die units 1 and 21 according to the first and second embodiments is that the medium passage is completely separated and independent from the passage through which the heated medium flows and the passage through which the cooled medium flows. It is a point provided.

That is, the insert 33A is provided with two medium passages 36Aa and 36Ab, and the insert 33B is provided with two medium passages 36Ba and 36Bb. These medium passages 36Aa, 36Ab, 36Ba and 36Bb are The heating / circulation means 38 and the cooling / circulation means 39 are connected to each other through independent heating medium piping 38a and cooling medium piping 39a.
Therefore, a medium made of different substances can be selected as the heating medium and the cooling medium. In Example 3, dibenzyltoluene was used as the heating medium, and water was used as the cooling medium.

Further, as a difference from the first and second embodiments, a pair of contact sensors as the mold opening detecting means 40 is provided on the portion corresponding to the boundary surface (partition surface) between the upper mold 32A and the lower mold 32B. Provided respectively on the lower surface and the upper surface of the lower mold 32B, when the mold is closed and the lower surface of the upper mold 32A contacts the upper surface of the lower mold 32B, a contact signal is output, the mold is opened and the upper mold 32A is opened. When the lower surface of the mold is separated from the upper surface of the lower mold 32B, a mold opening signal is output.
A cavity filling detection means 41 is provided in the vicinity of the molding cavity 35. In the third embodiment, as the cavity filling detecting means 41, the thermocouple (K type) having a high response speed used as the cavity temperature measuring means in the first and second embodiments is used in the vicinity of the molding cavity 35 of the insert 33B. Installed.

Also in the third embodiment, the lower mold 32B and the insert 33B are provided with the gas vent 43 and the exhaust hole 44 connected from the gas vent 43 to the outside of the lower mold 32B.
Further, in the third embodiment, rock wool 37 as a heat insulating material is provided as a heat insulating means for heat insulating between the inserts 33A and 33B and the resin molding dies 32A and 32B excluding the inserts 33A and 33B. ing.

Further, a control means 42 is provided for receiving the output signals from the mold opening detection means 40 and the cavity filling detection means 41 and controlling the heating / circulation means 38 and the cooling / circulation means 39. Similarly to the control means 12, the control means 42 also has an input port for receiving electrical signals output from the mold opening detection means 40 and the cavity filling detection means 41, and an A / D converter that converts the electrical signals into digital signals. The computer system includes an arithmetic unit having a central processing unit (CPU) and a memory device, a D / A converter that converts a digital signal into an analog signal, and an output port that outputs the analog signal.
In addition, from the heating / circulation means 38 and the cooling / circulation means 39, operation signals are input to the input ports of the control means 42 when the respective heating mechanisms and cooling mechanisms are operating.

  13 is a schematic diagram. In FIG. 13, the molten resin MR is drawn through the gate cavity 34 from the right side surface of the injection molds 32A and 32B. The molds 32A and 32B are multi-cavity molds having a plurality of molding cavities 35. The injection nozzle of the injection molding machine is in contact with the upper surface of the upper mold 32A, and the molten resin MR flows from the upper surface of the upper mold 32A.

A temperature control method in the resin molding die unit 31 according to the third embodiment having such a configuration will be described with reference to the flowcharts of FIGS. 13 and 14.
First, when the injection molding is started, the injection molding machine is turned on, and the heating and cooling mechanism operation switches of the heating / circulation means 8 and the cooling / circulation means 9 are turned on. As a result, the resin molding die unit 31 is operated, and control is started in step S21. In step S22, whether or not injection molding is in progress is controlled by operating signals from the heating / circulation means 38 and the cooling / circulation means 39. The determination is made based on whether or not the signal is input to the input port of the means 42. If the injection molding is not in progress, the heating / circulation means 38 and the cooling / circulation means 39 are completely stopped in step S28, and the control is terminated in step S29.

On the other hand, if injection molding is in progress, it is determined in step S23 whether or not a mold opening signal has been input, and when the upper mold 32A and the lower mold 32B are opened, 1 as the mold opening detecting means 40 is detected. Since the mold opening signal is output from the pair of contact sensors and is input to the control means 42, the process proceeds to step S24, and the control means 42 outputs a signal for operating the circulation means of the heating / circulation means 38, and the heating. -Dibenzyltoluene as a medium heated to 250 ° C. is caused to flow from the circulation means 38 to the medium passages 36Aa and 36Ba through the heating medium pipe 38a. Then, the process returns to step S22.
If the mold opening signal has not been input, the process proceeds to step S25 to determine whether or not a cavity filling signal has been input.

While step S24 is being performed, the upper mold 32A and the lower mold 32B are closed to form the inside of the molding cavity 35, and polyethylene terephthalate as a molten resin MR heated and melted to 300 ° C. from an injection molding machine (not shown). (Hereinafter also referred to as “PET”) (softening point of about 260 ° C.) flows into the molding cavity 35 via the gate cavity 34 and is filled. As a result, the thermocouple serving as the cavity filling detecting means 41 detects that the molding cavity 35 is indirectly filled when the temperature inside the molding cavity 35 exceeds a predetermined temperature, and the cavity filling signal is controlled. Input to means 42.
In response to this, the process proceeds from step S25 to step S26, and the control means 42 outputs a signal for stopping the circulation mechanism of the heating / circulation means 38 and operating the circulation mechanism of the cooling / circulation means 39, The flow of dibenzyltoluene heated to 250 ° C. stops, and water as a medium cooled to 20 ° C. flows from the cooling / circulation means 39 to the medium passages 36Ab and 36Bb through the cooling medium piping 39a. Then, the process returns to step S22.

When the upper mold 32A and the lower mold 32B are opened again after a predetermined time has passed, a mold opening signal is output from a pair of contact sensors as the mold opening detecting means 40, and in response to this, a step opening signal is received from step S23 to step S24. The control means 42 outputs a signal for stopping the circulation mechanism of the cooling / circulation means 39 and operating the circulation mechanism of the heating / circulation means 38, and the flow of water cooled to 20 ° C. is stopped. Dibenzyltoluene as a medium heated to 250 ° C. flows from the heating / circulation means 38 to the medium passages 36Aa and 36Ba through the heating medium pipe 38a.
This control is determined not to be in the injection molding at step S22, the heating / circulation means 38 and the cooling / circulation means 39 are completely stopped at step S27, and are repeated until the control is finished at step S28.

In this way, by repeating heating / cooling of only the inserts 33A and 33B, so-called heat cycle molding is carried out, so that even if PET, which is an engineering plastic, is used as a synthetic resin, occurrence of weld lines, transfer defects, etc. Precise prevention and precise resin molding can be obtained.
Moreover, since only the inserts 33A and 33B are heated and cooled, energy saving can be achieved, and inexpensive contact sensors and thermocouples are used as means for determining the timing for switching between heating and cooling. Therefore, the equipment cost can be reduced.

  Thus, in the resin molding die unit 31 and the resin molding die temperature control method according to the third embodiment, the equipment cost is suppressed and the mold temperature only around the cavity is required. As a result, it is possible to reliably prevent the occurrence of weld lines and transfer defects and to obtain a precise resin molded product, and to reduce the initial cost and the running cost.

  In each of the above embodiments, the case of a pair of resin molding dies including the upper molds 2A and 32A and the lower molds 2B and 32B has been described as the resin molding molds constituting the resin molding mold unit. The pair of resin molding dies is not limited to such a vertical type, but may be a horizontal type. Further, the present invention is not necessarily limited to a pair of resin molding dies, and can also be applied to resin molding dies formed by combining three or more dies.

  In each of the above-described embodiments, the case where the resin handle of the automobile door is molded as the resin molded product molded by the resin molding die unit has been described. However, the resin molded product is not limited thereto. Instead, the mold unit for resin molding according to the present invention can be applied to molding any shape of resin molded product.

  Further, in each of the above-described embodiments, the description has been given only of the case where the gas venting gaps of the gas vents 11 and 43 are provided on the back side on the side into which the tip portion P3 of the molten resin MR flows. The clearance may be provided in any part.

In each of the above embodiments, the case where PEEK (polyether ether ketone), polycarbonate, and PET (polyethylene terephthalate) are used as the synthetic resin for molding a resin molded product has been described. In addition, other general-purpose plastics such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, ABS resin, AS resin, acrylic resin, fluororesins such as PFA, FEP, etc., polyamide as engineering plastic Super engineering plastics such as polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, glass fiber reinforced polyethylene terephthalate (GF-PET), which is a kind of FRP, cyclic polyolefin, etc. Te polyphenylene sulfide, polytetrafluoroethylene, polysulfone, polyether sulfone, acrylate polymer, it is possible to use a liquid crystal polymer, thermoplastic polyimide, polyamideimide and the like.
As the thermosetting resin, phenol resin, epoxy resin, melamine resin, urea resin, unsaturated polyester resin, alkyd resin, polyurethane, thermosetting polyimide, or the like can be used.

  In practicing the present invention, the configuration, structure, shape, material, quantity, size, connection relationship, etc. of other parts of the resin molding die unit, and other methods for controlling the temperature of the resin molding die This process is not limited to the above embodiments. In addition, since the numerical value quoted in the embodiment of the present invention does not indicate a critical value but indicates an appropriate value suitable for implementation, even if the numerical value is slightly changed, the implementation is not denied. Absent.

1,21,31 Resin molding mold unit 2A, 2B, 32A, 32B Resin molding mold 3A, 3B, 3AA, 3AB, 3BA, 3BB, 33A, 33B Nest 5,5A, 5B, 35 Mold cavity 6A , 6B, 36Aa, 36Ab, 36Ba, 36Bb Medium passage 7, 37 Heat insulation means 8, 28, 38 Heating / circulation means 8a, 28a, 38a Heating medium piping 9, 29, 39 Cooling / circulation means 9a, 29a, 39a Cooling medium Pipe 10 Cavity temperature measuring means 11, 11A, 11B, 43 Gas vent 12, 42 Control means 14A Closing member 14Aa Piston part 14Ab Tip part 15A Cylinder part 16A Spring member 20 Ejector pin 22 Medium temperature measuring means 23 Switching means 24 Switching control means 40 Mold opening detection means 41 Cavity filling detection means MR Molten tree Fat W1 resin molded product

Claims (11)

A resin molding die unit having a resin molding die for forming a molding cavity for molding a resin molded product made of the synthetic resin with a molten synthetic resin (hereinafter also referred to as “molten resin”). ,
A nest that forms the molding cavity provided in the resin molding die;
One or more medium passages for passing a temperature control medium provided in the nest;
Heat insulating means for insulating heat between the insert and the mold for resin molding excluding the insert;
Heating / circulating means for heating and circulating the temperature control medium;
Cooling and circulation means for cooling and circulating the temperature control medium;
A heating medium pipe connecting the medium passage and the heating / circulation means;
A cooling medium pipe connecting the medium passage and the cooling / circulation means;
A cavity temperature measuring means that is provided in the vicinity of the molding cavity of the insert and measures the temperature in the molding cavity;
When the temperature in the molding cavity measured by the cavity temperature measuring means falls below a predetermined lower limit temperature, the cooling / circulating means stops the flow of the cooled medium, and the heating / circulating means is passed through the medium passage. When the temperature inside the molding cavity measured by the cavity temperature measuring means exceeds a predetermined upper limit temperature, the flow of the heated medium from the heating / circulating means is interrupted to stop the flow of the heated medium. A resin molding die unit comprising: the heating / circulation means and a control means for controlling the cooling / circulation means so that the medium cooled from the cooling / circulation means flows through the medium passage.   The mold unit for resin molding according to claim 1, wherein the cavity temperature measuring means is a thermocouple or a resistance temperature detector. A resin molding die unit having a resin molding die for forming a molding cavity for molding a resin molded product made of the synthetic resin with a molten synthetic resin (hereinafter also referred to as “molten resin”). ,
A nest that forms the molding cavity provided in the resin molding die;
One or more medium passages for passing a temperature control medium provided only in the nest;
Heat insulating means for insulating heat between the insert and the mold for resin molding excluding the insert;
Heating / circulating means for heating and circulating the temperature control medium;
Cooling and circulation means for cooling and circulating the temperature control medium;
A heating medium pipe connecting the medium passage and the heating / circulation means;
A cooling medium pipe connecting the medium passage and the cooling / circulation means;
Mold opening detecting means for detecting that the resin molding mold is opened and outputting a mold opening signal;
Cavity filling detection means for detecting that the molding cavity is filled with the molten resin and outputting a cavity filling signal;
Interrupting the flow of the cooled medium from the cooling / circulation means when a mold opening signal is output from the mold opening detection means, and flowing the heated medium from the heating / circulation means to the medium passage; When a cavity filling signal is output from the cavity filling detection means, the flow of the heated medium from the heating / circulation means is interrupted, and the medium cooled by the cooling / circulation means is caused to flow in the medium passage. A mold unit for resin molding, comprising: a control unit that controls the heating / circulation unit and the cooling / circulation unit. The medium heated by the heating / circulation means and the medium cooled by the cooling / circulation means are the same substance,
Switching means for flowing the medium passing through the medium passage and out of the insert to either the heating / circulation means or the cooling / circulation means;
Medium temperature measuring means for measuring the temperature of the medium passing through the medium passage and coming out of the nest;
If the temperature of the medium measured by the medium temperature measuring means is equal to or higher than a predetermined temperature, the medium is passed through the heating / circulating means, and if the temperature of the medium measured by the temperature measuring means is lower than the predetermined temperature, the medium 4. A resin molding die unit according to claim 1, further comprising switching control means for controlling the switching means so as to flow through the cooling / circulation means. 5. .   The mold unit for resin molding according to claim 4, wherein the predetermined temperature is a softening temperature or a glass transition temperature of the synthetic resin. The resin molding die has a gate cavity for guiding the molten resin to the molding cavity,
Provided in a portion of the molding cavity away from the gate cavity and formed integrally with a cylinder portion provided in the resin molding die, a piston portion slidably fitted in the cylinder portion, and the piston portion. A gas vent comprising a closing member having a tip portion constituting a part of the molding cavity;
The cylinder portion communicates with the outside of the resin molding die, and the gas vent is opened when the end of the molten resin passes through the gate cavity, and the pressure of the molten resin The mold unit for resin molding according to any one of claims 1 to 5, wherein the closing member is closed by pressing the front end portion of the closing member and sliding the closing member. A temperature control method for a resin molding die for forming a molding cavity for molding a resin molded product made of a synthetic resin with a molten synthetic resin (hereinafter also referred to as “molten resin”),
The resin mold is provided with a nest that forms the molding cavity,
Providing one or more medium passages for passing a temperature control medium only in the nest;
Insulate between the insert and the resin molding mold excluding the insert,
When the temperature in the molding cavity is indirectly measured and the temperature in the molding cavity falls below a predetermined lower limit temperature, the flow of a low-temperature cooling medium to the medium path is interrupted, and the high-temperature heating medium in the medium path Shed
When the temperature in the molding cavity exceeds a predetermined upper limit temperature, the flow of the high-temperature heating medium to the medium passage is interrupted, and the low-temperature cooling medium is caused to flow to the medium passage,
A temperature control method for a resin molding die, wherein the high-temperature heating medium and the low-temperature heating medium are alternately passed through the medium passage. A temperature control method for a resin molding die for forming a molding cavity for molding a resin molded product made of a synthetic resin with a molten synthetic resin (hereinafter also referred to as “molten resin”),
The resin mold is provided with a nest that forms the molding cavity,
Providing one or more medium passages for passing a temperature control medium only in the nest;
Insulate between the insert and the resin molding mold excluding the insert,
When the resin molding die is opened, the flow of the low-temperature cooling medium to the medium passage is interrupted, and the high-temperature heating medium is caused to flow to the medium passage,
When the molten resin is filled in the molding cavity, the flow of a high-temperature heating medium to the medium passage is interrupted and a low-temperature cooling medium is caused to flow to the medium passage,
A temperature control method for a resin molding die, wherein the high-temperature heating medium and the low-temperature heating medium are alternately passed through the medium passage. The heating medium and the cooling medium are media made of the same material,
A heating means for heating the medium connected to the medium passage and a cooling means for cooling the medium are arranged outside the resin molding die,
The temperature of the medium passing through the medium passage and coming out of the insert is measured. If the temperature is equal to or higher than a predetermined temperature, the medium is flowed to the heating means. The method for controlling the temperature of the resin molding die according to claim 7 or 8, wherein the temperature of the resin molding die is passed through the cooling means.   The temperature control method for a resin molding die according to claim 9, wherein the predetermined temperature is a softening temperature or a glass transition temperature of the synthetic resin. The mold for resin molding includes a gate cavity for guiding the molten resin to the molding cavity, and a gas vent provided in a part of the molding cavity away from the gate cavity,
The gas vent communicates with the outside of the resin molding die, and the gas vent is opened when the tip of the molten resin passes through the gate cavity and is closed by the pressure of the molten resin. The temperature control method for a resin molding die according to any one of claims 7 to 10, characterized in that:

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