JPH06190886A - Apparatus for gradual cooling of cavity unit - Google Patents

Abstract

(57) [Summary] [Object] The present invention relates to a gradual cooling device for a cavity unit, and to produce a molding system and a molding method for performing multi-product mixed production using a plurality of cavity units by efficiently performing gradual cooling. The purpose is to improve sex and quality. [Structure] A plurality of cavity units 1 each having a pair of molds so that a cavity is formed therein, a predetermined heating station 2, a filling / relaxation station 3,
In the molding system in which the slow cooling station 4 and the molded product take-out station 5 are carried in this order to mold a resin molded product having a shape corresponding to the cavity, the slow cooling station 4 is provided with the cavity unit 1. A slow cooling stage 11 for cooling and a cooling stage 12 for slow cooling at a cooling rate different from that of the slow cooling stage 11 while making the temperature distribution in the cavity uniform are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slow cooling device for a cavity unit and a slow cooling method for the same, and more particularly to a slow cooling device for a cavity unit which is effective when provided in a molding system for injection molding precision molded products such as plastic lenses. And its slow cooling method.

[0002]

2. Description of the Related Art In recent years, due to higher precision of plastic molding, various injection moldings have been carried out by utilizing its advantages, for example, precision moldings such as plastic lenses (optical elements). In such molding, in order to improve the shape transfer accuracy by the molding die, it is necessary to continue to apply an appropriate pressure immediately before the resin is completely filled in the cavity until the filled resin is solidified.

On the other hand, as an excellent method for realizing this,
A molding method called a gate seal molding method has been proposed. In this molding method, for example, in order to eliminate the occurrence of non-uniformity of resin pressure and resin temperature due to the orientation and pressure distribution of the resin, the mold temperature is raised to a predetermined temperature by heating the mold, and injection filling is performed. The gate is sealed to stop the flow of the resin, and then the mold is kept at a temperature not lower than the glass transition point to relax the resin to make the pressure and temperature of the resin in the cavity uniform, and then Slowly slowly cool to below the heat distortion temperature and take out the molded product when the resin pressure has dropped sufficiently. By this method, it is possible to accurately mold even an uneven thickness optical element having a thick portion and a thin portion, let alone a molded article having a uniform thickness. Moreover, since a plurality of cavity units each having the cavity formed therein can be used, various cavity units can be used on the same line, and mixed production for molding molded articles of various shapes (so-called, Mixed production of various kinds) can be efficiently performed. This molding method is characterized in that the molten resin is injected and filled at a high pressure into the cavity of the cavity unit that is uniformly heated to the glass transition temperature of the resin to be injected and filled into the cavity, and then the resin is injected into the cavity. It is to cool slowly to the heat distortion temperature or lower.

As a method of gradually cooling the cavity unit in this molding method, for example, a method of gradually cooling by blowing air, that is, an air cooling method can be considered, and a method of bringing a cooling block into close contact with the cavity unit can be considered.

[0005]

However, in the slow cooling method in which slow cooling is performed by air cooling as described above, when it is desired to perform multi-step slow cooling (for example, rapid cooling below the glass transition temperature of the resin is desired. It is difficult to respond to the case) instantly. In addition, if the number of cavity units is large or the cavity units are large due to the shape of the molded product, it may not be possible to gradually cool to the heat deformation temperature within a predetermined time. Therefore, it is difficult to improve productivity by performing multi-product mixed production using cavity units of different products. Therefore, a method of gradually cooling to below the thermal deformation temperature and then bringing a cooling block into close contact with the cavity unit to rapidly cool it may be considered. However, in such a slow cooling method, when the shape of the molded product to be molded has a thick wall, uneven thickness, or irregular shape (for example, a prism or a long lens), or a cavity having a plurality of cavities is formed. When performing multi-product mixed production using a unit, since slow cooling control for each part of the cavity unit is not sufficient, a temperature distribution is generated and a high quality molded product cannot be stably molded.

Therefore, the present invention has been made in view of such a conventional problem, and the slow cooling which takes the longest time in the above-mentioned injection molding is efficiently performed while making the temperature distribution in the cavity unit uniform. By doing so, it is possible to enable multi-product mixed production using a plurality of cavity units and to improve the productivity and quality of injection molding.

[0007]

In order to achieve the above object, the invention according to claim 1 is provided with a plurality of cavity units each having a pair of molds so that a cavity is formed therein, a predetermined heating station and a filling unit. In a molding system in which a relaxation unit, a slow cooling station, and a molded product take-out station are carried in this order to mold a resin molded product having a shape corresponding to the cavity, the slow cooling station is provided with the cavity unit. The gradual cooling stage for cooling and a cooling stage for gradual cooling at a cooling rate different from that of the gradual cooling stage while making the temperature distribution in the cavity uniform are provided. In the invention of claim 1, the molding system gate-seals the cavity unit in which the cavity is filled with resin. It is characterized in that it is Lumpur molding system.

The invention according to claim 3 is characterized in that a plurality of the slow cooling stages are provided, and the invention according to claim 4 is such that the cooling stage can be brought into close contact with the cavity unit. The invention according to claim 5 is characterized in that a temperature adjusting mechanism is provided in the cooling block, and the invention according to claim 6 is characterized in that The temperature control mechanism uses water as a medium, and the temperature control mechanism is characterized in that
The invention described above is characterized in that the temperature adjusting mechanism uses oil as a medium.

The invention according to claim 8 is characterized in that the cooling block is provided with a distribution adjusting means for making the temperature distribution in the cavity uniform. The invention according to claim 9 is characterized in that the cooling block is formed of a metal, and the invention according to claim 10 is characterized in that the cooling block is formed of a heat insulating material. The invention according to claim 11 is characterized in that a heat insulating material is detachably attached to the cooling block formed of the metal.

The invention according to claim 12 is characterized in that the slow cooling stage is for gradually cooling the cavity by blowing air, and the invention according to claim 13 is the slow cooling stage. 15. The invention according to claim 14 is characterized in that a wind force control means for controlling the wind force of the air blow is provided, wherein the wind force control means sucks the suction air around the transfer line of the cavity unit. It is characterized by having a suction duct with adjustable force,
A fifteenth aspect of the present invention is characterized in that the air flow control means has a fan capable of adjusting the air flow rate around the transfer line of the cavity unit.

Further, the invention according to claim 16 is characterized in that a carrying speed control means for controlling a carrying speed of the cavity unit on the slow cooling stage and / or the cooling stage is provided. The invention described in 17 is
The cooling block moves in the carrying direction of the cavity unit while being in close contact with the cavity unit.

According to the eighteenth aspect of the present invention, a plurality of cavity units each having a pair of molds so that a cavity is formed therein is used, the cavity units are heated to a predetermined temperature, and the molten resin is filled in the cavities. In an injection molding method of injection-filling, and then gradually cooling to a temperature not higher than the thermal deformation temperature of the resin to mold a resin molded product having a shape corresponding to the cavity, when slowly cooling the cavity unit, At least 2 from the predetermined temperature to the heat deformation temperature while making the temperature distribution in the cavity unit uniform.
It is characterized by gradually cooling at different cooling rates of at least one kind.

[0013]

According to the present invention, the plurality of cavity units are gradually cooled by the slow cooling stage and the cooling stage having a different cooling rate from the slow cooling stage. Therefore, the cooling rate can be controlled efficiently. And the productivity of the molding system is increased. Further, in the cooling stage, the temperature distribution in the cavity is made uniform while being gradually cooled, so that a high quality molded product can be stably produced.

According to the fifth aspect of the present invention, by using the temperature adjusting mechanism in the cooling stage, rapid cooling is possible, and the cooling block heated by the heat from the cavity unit is quickly returned to the initial state. Can be made. According to the invention described in claim 8, by providing the distribution adjusting means on the cooling stage, it becomes possible to gradually cool at a cooling rate suitable for the shape of the molded product and the molding material while making the inside of the cavity uniform.

In the inventions according to claims 9 to 11, by using a cooling block made of a metal having good thermal conductivity at the time of rapid cooling in the cooling stage, and by using a cooling block made of a heat insulating material at the time of super slow cooling, Efficient gradual cooling suitable for the required cooling rate becomes possible. In the inventions of claims 12 to 15, by performing gradual cooling by blowing air in the gradual cooling stage, each part of the cavity unit can be gradually cooled at a uniform cooling rate, and finer control is provided by the blowing force control. Control becomes possible.

In the sixteenth aspect of the present invention, by controlling the conveying speed, it becomes possible to easily cool the target temperature in a predetermined time in combination with the combined use of the slow cooling stage and the cooling stage. According to the invention of claim 17, by increasing the cooling rate in the cooling stage, more efficient gradual cooling becomes possible.

According to the eighteenth aspect of the present invention, since the temperature distribution in the cavity unit is made uniform and the cooling is gradually performed at at least two or more different cooling rates, the cooling rate can be efficiently controlled, and the injection molding production can be performed. Sex and quality are enhanced.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 are views showing an example of a slow cooling device for a cavity unit for carrying out the slow cooling method for a cavity unit according to the present invention. An example in which the present invention is applied to a slow cooling device for a gate seal molding system. Is shown.

First, the structure will be described. Figure 1
In FIG. 7, 1 is a plurality of cavity units.
Although these cavity units 1 are not shown in detail,
Each is composed of a pair of upper and lower molds so as to form a cavity of a predetermined shape inside. The plurality of cavity units 1 are conveyed by a well-known conveying means 6 using a chain or the like, heated in a predetermined heating station 2, and then sent to a filling / relaxation station 3 where the filling / relaxation station 3 is operated. The molten resin is injected and filled in the cavity, the gate is sealed, the temperature and pressure are relaxed, and then it is transferred to the slow cooling station 4 and slowly cooled to a temperature not higher than the heat deformation temperature, and the molded product is taken out at the molded product take-out station 5. Molded for. The work and transfer work of these stations are controlled by a control panel (not shown).

The heating station 2 is a place for heating the cavity unit 1 and is provided with a plurality of mold heating devices 21, 22, 23 as its heating means. Mold heating device 21 ~
Each of the 23 includes, for example, a pair of L-shaped heater blocks made of a copper material having good thermal conductivity, a plurality of rod-shaped heaters and thermocouples embedded in each heater block, and a lower heater block. It has a general clamp type tightening means that is vertically fixed on the substrate and a heater block retainer connected to the upper heater block by a plurality of bolts. Then, the cavity unit 1 inserted into the space between the heater blocks is clamped by the tightening means, or the clamped state is released. A heater controller cooperates with the thermocouple to manage the heat generation amount of the rod-shaped heater.

In the heating method of this embodiment, for example, the mold heating device 21, which is the first heating stage, is set to a temperature slightly higher than the target temperature (injection temperature), and then the second and third heatings are performed. A step heating system is adopted in which the mold units 22 and 23, which are stages, are used to uniformly heat the cavity unit 1. The shape of the heater block does not necessarily have to be L-shaped and may be heated from each of the four directions (four-side heating), and the material of the heater block may be, for example, aluminum having good heat conductivity instead of the above-mentioned copper material. Materials can be used. Further, the tightening method of the tightening means can also obtain a sufficient tightening force by some power such as hydraulic pressure and pneumatic pressure.

In the filling / relaxation station 3, resin is injected and filled into the cavity of the cavity unit 1 at a high pressure to alleviate uneven distribution of resin temperature and pressure after filling. When the injection is completed, the valve body (gate seal means) arranged in the resin supply passage (not shown) in the cavity unit 1 is pressure-adhered to the valve-seat-shaped gate by the differential pressure across the cavity (high pressure on the cavity side). The seal is made. In addition, the injection / filling work is performed, for example, by a known injection molding machine 7 (injection filling means) in 10
It is designed to be performed at a high pressure of 00 kgf / cm2 or more. A heat retaining heater is embedded in the die plate of the injection molding machine 7, and a mold positioning jig for positioning the cavity unit 1 at a predetermined position is attached.

In the filling / relaxation station 3 of this embodiment, the cavity unit 1 is tightened in the direction orthogonal to the mold clamping direction by the pressing mechanism composed of the hydraulic cylinder and the abutting member. The cavity unit 1 having a relatively low rigidity is prevented from being deformed so as to open in the orthogonal direction at the time of injection filling. On the other hand, the cavity unit 1 is provided with a self-holding mechanism (not shown), and the self-holding mechanism can hold a predetermined mold clamping force. Specifically, the self-holding mechanism has a plurality of self-holding bolts that connect the upper and lower molds of the cavity unit 1 by tightening them in the mold clamping direction in the vicinity of the cavity. Is threadedly connected to the lower mold. By adopting this self-holding mechanism, after the filling / relaxation by the injection molding machine 7, the injection molding machine 7 is opened with the gate of the cavity unit 1 sealed by the moving valve body, and the cavity unit 1 is gradually cooled independently. It is possible to maintain a predetermined pressure holding state that does not depend on the injection molding machine 7.

The slow cooling station 4 is for gradually cooling the cavity unit 1 taken out of the injection molding machine 7 by opening it at a desired cooling rate to a temperature not higher than the heat deformation temperature (solidification temperature). As conceptually shown in FIG. 1, it comprises a plurality of slow cooling stages 11 and a plurality of cooling stages 12. As shown in FIG. 3, the plurality of slow cooling stages 11 correspond to the plurality of forced exhaust ducts 43 (suction ducts with adjustable suction force) of the air type slow cooling device 41 on the mold transfer unit 42. Is provided. The die transfer section 42 (transfer speed control means)
A part of the conveying means 6 is configured, and for example, it advances at a constant speed for a set count number or stops for a set stop time. Further, it is set such that the time of one molding cycle = the moving time of the cavity unit 1 + the stop time. The forced exhaust duct 43 is provided for the purpose of causing a flow of air inside the cover to gradually cool the cavity unit 1 at a desired slow cooling rate, and a shield plate 44 ( The wind force control means) changes the inclination, so that the air recovery port 43 of each exhaust duct 43
It serves as an opening / closing means for independently opening / closing a, and has a function of independently adjusting the intake air volume (suction force) of the exhaust duct 43 by this opening / closing means. In addition, the die transfer section
A plurality of fans 45 (air supply control means) capable of adjusting air flow (air supply) are provided above and below 42 and between the air recovery ports 43a of each exhaust duct 43. The fans 45 may be provided on the left and right sides of the die transfer section 42.

As shown in FIGS. 4 to 7, the cooling stage 12 has four (plural) cooling blocks 14 which closely contact the upper, lower, left and right surfaces of the cavity unit 1 to remove heat. It has a hydraulic device (not shown) in close contact with the unit 1, and a moving means for moving the cooling block 14, the cavity unit 1 and the like integrally.
Here, the cooling block 14 is configured to cool the cavity unit 1 from four directions of up, down, left and right as shown in FIG. 5, and this cooling block 14 is made of, for example, a metal having good thermal conductivity (eg, copper or aluminum). Are formed from. Further, a temperature adjusting mechanism (hereinafter simply referred to as a temperature adjusting mechanism) 15 having a cooling pipe for passing a cooling medium inside the cooling block 14
A heater embedded plate 20 including a heater 21a is provided, and the heater embedded plate 20 is sandwiched by the metal provided with the temperature control mechanism 15 so as to face the outer surface of the cavity unit 1.

The cooling block 14 cools the cavity unit 1 by selecting water or oil as a medium to be used in accordance with the target cooling condition of the temperature control mechanism 15, and also the heater embedded plate 20.
The heater 21a heats each part of the cavity unit 1 so that a temperature difference is not generated in the cavity of the cavity unit 1 and the temperature distribution is made uniform. That is, the heater embedding plate 20 constitutes distribution adjusting means. As shown in FIG. 6, the heater-embedded plate 20 is provided with a plurality of heater cartridges 21 in each of which a large number of heaters 21a are arranged. The heater cartridge 21 efficiently heats each part of the cavity unit 1 in accordance with the shape of the cavity, and The temperature distribution is made uniform. This heater embedding plate 20 efficiently replaces the heater 21a of the heater cartridge 21 with the heater cartridge 21 arranged in conformity with the shape of the cavity, and efficiently and uniformly corresponds to the shape of the cavity to make the temperature distribution uniform. be able to.

A thermocouple 16 is provided in each of the cooling blocks 14.
Is embedded, and the control panel selects the refrigerant to be passed through the cooling pipe of the temperature control mechanism 15 based on the temperature detection information of the thermocouple 16 and controls the energization of the heater 21a of the heater embedding plate 20 easily. Various cooling rates can be used, and cooling conditions suitable for the cavity shape and the resin (multi-stage cooling including the slow cooling stage 11) can be achieved. Furthermore, as shown in FIG. 7, these cooling blocks 14 have a structure (boss shape or groove shape) in which the heat insulating material 17 is detachably attached to the surface closely contacting the cavity unit 1.
Has become. Therefore, the cooling block 14 is a heat insulating material.
When 17 is not used (installed), the cavity unit 1 can be cooled (quenched) or cooled under a predetermined cooling condition at a cooling rate higher than that of the slow cooling stage 11 while making the temperature distribution in the cavity uniform. When the heat insulating material 17 is used, super slow cooling can be performed at a cooling rate considerably lower than that of the slow cooling stage 11. The temperature control mechanism 15
By controlling the temperature of the refrigerant, the cooling rate can be controlled more efficiently and easily.

The moving means moves the cooling block 14 along, for example, a predetermined loop-shaped orbit, and the cooling block 14 that has reached a predetermined position while being in close contact with the cavity unit 1 is moved by the hydraulic device. After being separated, it is moved by this moving means to make a U-turn and return to a position in which it closely contacts the cavity unit 1.
At the same time, it also serves as a transfer speed control means for controlling the transfer speed of the cavity unit 1.

In FIG. 2, reference numeral 18 denotes an identification mark. The identification mark 18 is attached to each of the predetermined positions of the cavity unit 1, and is read by an identification device (not shown) before being carried into the heating station 2. This identification mark 18
Is formed, for example, as a plurality of irregularities, and this sign 18
Is mechanically detected and an identification signal composed of a plurality of bits of 0N / OFF signals is used to enable identification of each mold. Then, each station controls each molding condition based on the identification mark 18.

The molded product take-out station 5 uses a well-known nut runner for the cavity unit 1 which has been slowly cooled to the taken-out temperature of the molded product in the slow cooling station 4.
After loosening the self-holding bolts of the self-holding mechanism,
The upper and lower molds are opened by a mold opening / closing device. The mold opening / closing device is formed on a peripheral portion of the cavity unit 1 by being attached to an elevating plate which is attached to a plurality of guide posts so as to be able to ascend and descend, a fixed plate fixed below the elevating plate, and an elevating plate. It is provided with an automatic clamp type (for example, an automatic type using a pneumatic cylinder) mold clamp that engages with the groove portion, a mold clamp attached to a fixed plate, and a lifting drive source (not shown). Further, since the cavity unit 1 does not have an eject mechanism, the molded product is taken out by a so-called take-out type take-out device (not shown). The cavity unit 1 from which the molded product is taken out is tightened with the self-holding bolt so that the mold is closed and clamped again by the nut runner.

Next, the operation will be described. First, the self-holding bolts of the cavity unit 1 are tightened by the mold opening / closing device of the molded product take-out station 5, and the cavity unit 1 is clamped and conveyed to the heating station 2. At this time, the identification mark 18 is read by the identification device to identify the type of the cavity unit 1.

Next, the cavity unit 1 transferred to the heating station 2 is uniformly heated to a predetermined temperature based on the identification information, and then transferred to the filling / relaxation station 3 and set (clamped) on the injection molding machine 7. ), And receives the mold clamping force from the injection molding machine 7. In addition to this mold clamping, the cavity unit 1 is also clamped by the pressing mechanism in the direction orthogonal to the mold clamping direction.
A predetermined amount of molten resin is injected and filled at a predetermined pressure by the injection molding machine 7 into the cavity in the cavity unit 1 based on the identification information, and when the injection is completed, the cavity unit and the sprue side resin have a differential pressure, which results in the cavity unit. The valve element in 1 is pressure-bonded to the gate to seal the gate. Next, the cavity unit 1 by the injection molding machine 7
The mold clamping is released, the cavity unit 1 is taken out of the injection molding machine 7 by opening the injection molding machine 7 and unclamping the pressing mechanism, and the cavity unit 1 is sent to the slow cooling station 4.

Next, the cavity unit 1 sent to the slow cooling station 4 is controlled by the slow cooling stage 11 at a slow cooling rate at which the air type slow cooling device 41 opens and closes the shielding plate 44 and finely controls the air volume of the fan 45. Each part of the cavity unit 1 is uniformly air-cooled and gradually cooled to a predetermined temperature under a predetermined cooling condition. Then, in the cooling stage 12, while the temperature is adjusted to the glass transition temperature of the resin by the heater embedding plate 20 of the cooling block 14 so that the temperature distribution in the cavity of the cavity unit 1 becomes uniform, the identification information is obtained by the temperature adjustment function 15. Based on the above, it is slowly cooled slowly under high precision cooling conditions.
Next, after reaching the glass transition temperature and further decreasing to some extent, the heater 21a of the heater embedding plate 20 is de-energized, the refrigerant is forcibly passed through the temperature adjusting mechanism 15 and rapidly cooled, and the cavity unit 1 The cooling block 14 whose temperature has been raised by the heat from is quickly returned to the initial state.

In summary, in this cooling station 4,
Since the plurality of cavity units 1 are gradually cooled by the slow cooling stage 11 and the cooling stage 12 having a different cooling rate from the slow cooling stage, the cooling rate is controlled more efficiently, for example, shown by the solid line and the broken line in FIG. As described above, various multi-step gradual cooling, such as slow gradual cooling to the glass transition temperature and then rapid cooling until the molded product is taken out, is efficiently performed. In addition, by controlling the transfer speed of the mold transfer unit 42, the combined use of the slow cooling stage 11 and the cooling stage 12 facilitates slow cooling to the target temperature in a predetermined time.
Further, the cooling block 14 made of a metal having good thermal conductivity is used as it is to increase the cooling speed in the cooling stage 12, or the heat insulating material 17 is attached to the cooling block 14 to reduce the cooling speed of the abutting portion to achieve ultra-low speed. By cooling or the like, optimum conditions suitable for the type of the cavity unit 1 are efficiently performed.

Next, the resin in the cavity unit 1 is solidified (cooled to the heat deformation temperature) by slow cooling of the cavity unit 1, the cavity unit 1 is conveyed to the molded product take-out station 5, and the self-holding bolt is loosened by the nut runner. Then, the mold of the cavity unit 1 is opened. The solidified molded product is the cavity unit 1.
Is taken out by the take-out type take-out device. Hereinafter, continuous molding is performed with the above series of steps as one cycle.

As described above, in the present embodiment, the plurality of cavity units 1 are made uniform by the gradual cooling stage 11 and the cooling stage 12 having a different cooling rate from the gradual cooling stage so that no temperature distribution is generated in the cavities. Since slow cooling is performed, efficient and highly accurate slow cooling can be performed even if a plurality of types of cavity units 1 having different shapes of molded products are used, and a large number of high quality molded products can be produced on the same line. It can be seeded. Further, it is possible to improve the productivity of the molding system in which a plurality of types are mixed.

Also, since the molding system is a gate seal molding system, it is possible to perform high-precision precision molding that takes advantage of the above-described slow cooling effect. Since a plurality of slow cooling stages 11 are provided, the number of cavity units 1 can be increased. Also, the plurality of cavity units 1 can be uniformly and gradually cooled. Further, since the cooling block 14 is brought into close contact with the cavity unit 1, efficient slow cooling including rapid cooling can be performed. By using the temperature adjusting mechanism 15, the cooling block 14 that has been heated by the heat from the cavity unit 1 can be promptly cooled. The initial state can be restored. Further, water can be used as a medium of the temperature adjusting mechanism 15 to obtain a temperature adjusting mechanism having a large cooling effect at low cost, or a mechanism for bringing the cooling block 14 into close contact with the cavity unit 1 can be used as a hydraulic mechanism. It can be used as a medium of the temperature adjusting mechanism 15, and can prevent rust and the like from occurring in the temperature adjusting mechanism 15.

Further, since the heater embedding plate 20 is provided in the cooling block 14, the temperature distribution of the cavity can be made uniform, and the cooling can be gradually performed at a more accurate cooling rate. It is also possible to control the temperature itself. Furthermore, the heater 21a arrangement of the heater cartridge 21 can be changed and the temperature distribution can be efficiently controlled according to the shape of the cavity.

Further, as the material of the cooling block 14, rapid cooling can be performed by using a metal having good thermal conductivity, or by using a heat insulating material, slow gradual cooling can be performed. In addition, the heat insulating material 17 is a cooling block.
It can be attached to and detached from 14 to easily change the cooling rate. Further, by performing the slow cooling using the plurality of suction ducts 43 in the slow cooling device 41, each part of the cavity unit 1 can be gradually cooled at a uniform cooling rate, and the wind force thereof is shielded.
The slow cooling rate can be finely controlled by controlling with 44. Further, a plurality of slow cooling stages 11 can be easily formed by using the suction duct 43 with adjustable suction force, and a slow cooling speed in the slow cooling stage 11 can be obtained by using the fan 45 with adjustable air volume. Can be easily varied to provide fine and efficient slow cooling.

Further, the slow cooling stage 11 and the cooling stage
In addition to the effect of using 12 together, cavity unit 1
The slow cooling time to the target temperature can be easily set by controlling the transport speed of. Further, by moving the cooling block 14 in the carrying direction in a state of being in close contact with the cavity unit 1, the cooling speed in the cooling stage 11 can be increased, and more efficient slow cooling can be performed. Further, by reading the identification mark 18 attached to the cavity unit 1 to identify the type of the cavity unit 1, optimal slow cooling can be performed for each.

In this embodiment, the heat insulating material 17 is removably attached to the cooling block 14, but a cooling block made of a heat insulating material may be provided to enable super slow cooling.

[0042]

According to the first aspect of the present invention, the plurality of cavity units are gradually cooled by the slow cooling stage and the cooling stage having a different cooling speed from the slow cooling stage. Can be controlled efficiently, and the productivity of the molding system can be increased. Further, since the cooling stage makes the temperature distribution in the cavity uniform and gradually cools, a high quality molded product can be stably produced.

According to the second aspect of the invention, since the molding system is the gate seal molding system, it is possible to carry out high precision precision molding by utilizing the effect of the slow cooling. According to the third aspect of the invention, since the plurality of slow cooling stages are provided, even if the number of cavity units is increased, the plurality of cavity units can be uniformly cooled.

According to the fourth aspect of the invention, since the cooling block is closely attached to the cavity unit, rapid cooling can be performed and efficient slow cooling can be performed. According to the fifth aspect of the invention, by using the temperature adjusting mechanism, rapid cooling is possible, and moreover, the cooling block heated by the heat from the cavity unit can be quickly returned to the initial state.

According to the sixth aspect of the invention, since water is used as the medium of the temperature adjusting mechanism, it is possible to obtain a temperature adjusting mechanism having a large cooling effect at low cost. According to the invention described in claim 7, for example, a mechanism for bringing the cooling block into close contact with the cavity unit can be made into a hydraulic mechanism, and the oil can be used as a medium of the temperature adjusting mechanism, and furthermore, the occurrence of rust and the like in the temperature adjusting mechanism Can be prevented.

According to the eighth aspect of the present invention, since the cooling stage is provided with the distribution adjusting means, the inside of the cavity is made uniform, and the cooling is performed at a highly accurate cooling rate that is close to the shape of the molded product and the molding material. Therefore, it is possible to stably produce high-quality molded products. According to the invention described in claim 9, by using the cooling block made of metal having good thermal conductivity, rapid cooling can be performed and efficient slow cooling can be performed.

According to the tenth aspect of the present invention, the use of the cooling block made of a heat insulating material enables slow gradual cooling. According to the invention of claim 11, the heat insulating material can be attached to and detached from the cooling block to easily change the cooling rate. According to the twelfth aspect of the present invention, by performing gradual cooling by blowing air, each part of the cavity unit can be gradually cooled at a uniform cooling rate.

According to the thirteenth aspect of the invention, the slow cooling rate in the slow cooling stage can be finely controlled by the air flow control means. According to the invention of claim 14,
By using the suction duct whose suction force can be adjusted, a plurality of slow cooling stages can be easily formed, and more uniform slow cooling can be performed. According to the fifteenth aspect of the present invention, since the air flow rate is controlled by using the fan capable of adjusting the air flow rate, the slow cooling rate in the slow cooling stage can be easily changed to perform fine and efficient slow cooling.

According to the sixteenth aspect of the invention, in addition to the effect of using the slow cooling stage and the cooling stage together,
The slow cooling time to the target temperature can be easily set by controlling the transport speed of the cavity unit. According to the seventeenth aspect of the present invention, the cooling speed is increased in the cooling stage by moving the cooling block in close contact with the cavity unit, and more efficient slow cooling can be performed.

According to the eighteenth aspect of the present invention, since the temperature distribution in the cavity unit is made uniform and the cooling is gradually performed at at least two or more different cooling rates, the cooling rate can be efficiently controlled and the injection molding can be performed. The productivity and quality of can be increased.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a molding system showing an embodiment of a slow cooling device for a cavity unit according to the present invention.

FIG. 2 is a diagram conceptually showing the structure of a slow cooling station according to an embodiment.

FIG. 3 is a schematic configuration diagram of an air type slow cooling device having the slow cooling stage.

FIG. 4 is a perspective view showing a mounting state of a cooling block on the cooling stage.

FIG. 5 is a front view showing the configuration of the cooling block.

FIG. 6 is a plan view showing a configuration of distribution adjusting means of the cooling block.

FIG. 7 is a side view of the cooling block when a heat insulating material is attached.

FIG. 8 is a graph showing an example of multi-step slow cooling according to an example.

[Explanation of symbols]

 1 Cavity Unit 2 Heating Station 3 Filling / Mitigation Station 4 Slow Cooling Station 5 Molded Product Removal Station 6 Conveying Means 7 Injection Molding Machine 11 Slow Cooling Stage 12 Cooling Stage 14 Cooling Block 15 Temperature Control Mechanism 16 Thermocouple 17 Insulation 18 Identification Marker 20 Heater embedding plate (distribution adjusting means) 21 Heater cartridge 41 Pneumatic slow cooling device (cooling means) 42 Mold transfer section (transfer line, transfer speed control means) 43 Exhaust duct (suction duct) 44 Shielding plate (sending plate) Wind power control means) 45 Fan (wind force control means)

Claims (18)

[Claims] 1. A plurality of cavity units, each having a pair of molds so that a cavity is formed therein, are conveyed in order of a predetermined heating station, a filling / relaxation station, a slow cooling station, and a molded product unloading station. A molding system configured to mold a resin molded product having a shape corresponding to a cavity, wherein a slow cooling stage for slowly cooling the cavity unit in the slow cooling station, and a uniform temperature distribution in the cavity. A slow cooling device for a cavity unit, comprising: a slow cooling stage that cools slowly at a cooling rate different from that of the slow cooling stage. 2. The slow cooling device for a cavity unit according to claim 1, wherein the molding system is a gate seal molding system for sealing the cavity unit in which the cavity is filled with resin with a gate. 3. The slow cooling device for a cavity unit according to claim 1, wherein a plurality of slow cooling stages are provided. 4. The slow cooling device for a cavity unit according to claim 3, wherein the cooling stage has a cooling block that can be brought into close contact with the cavity unit. 5. The slow cooling device for a cavity unit according to claim 4, wherein a temperature adjusting mechanism is provided in the cooling block. 6. The slow cooling device for a cavity unit according to claim 5, wherein the temperature adjusting mechanism uses water as a medium. 7. The slow cooling device for a cavity unit according to claim 5, wherein the temperature adjusting mechanism uses oil as a medium. 8. The slow cooling device for a cavity unit according to claim 4, wherein a distribution adjusting means for uniformizing a temperature distribution in the cavity is provided in the cooling block. 9. The slow cooling device for a cavity unit according to claim 4, wherein the cooling block is made of metal. 10. The slow cooling device for a cavity unit according to claim 4, wherein the cooling block is formed of a heat insulating material. 11. A heat insulating material is detachably attached to the cooling block made of the metal.
A slow cooling device for the cavity unit described. 12. The slow cooling device for a cavity unit according to claim 3, wherein the slow cooling stage slows the cavity by blowing air. 13. The slow cooling device for a cavity unit according to claim 12, further comprising wind force control means for controlling the wind force of the wind blown by the slow cooling stage. 14. The slow cooling device for a cavity unit according to claim 13, wherein the air flow control means has a suction duct having a suction force adjustable around a transportation line of the cavity unit. 15. The slow cooling device for a cavity unit according to claim 13, wherein the air flow control means has a fan whose air flow rate can be adjusted around the transfer line of the cavity unit. 16. The slow cooling device for a cavity unit according to claim 3, further comprising a transport speed control means for controlling a transport speed of the cavity unit on the slow cooling stage and / or the cooling stage. 17. The slow cooling device for a cavity unit according to claim 4, wherein the cooling block moves in the transport direction of the cavity unit while being in close contact with the cavity unit. 18. A plurality of cavity units each having a pair of molds so that a cavity is formed therein, the cavity units are heated to a predetermined temperature, a molten resin is injected and filled into the cavities, and then, An injection molding method for gradually cooling to below the heat distortion temperature of the resin to mold a resin molded product having a shape corresponding to the cavity, wherein the temperature distribution in the cavity unit is uniform when the cavity unit is gradually cooled. The method for gradually cooling a cavity unit is characterized by gradually cooling from the predetermined temperature to the heat distortion temperature at at least two different cooling rates.