JPH11277539A - Method and apparatus for heating/cooling mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of molding by heating a cavity and a core in a short time and keeping a mold surface temperature high during injection. SOLUTION: With a cavity 3 separated from a fixed board side main mold 1 and a core 4 separated from a movable platen side main mold 2, only the cavity 3 and the core having low heat capacities are heated. In this way, a heating time can be reduced and the quality of molding can be improved. After the completion of injection, with mold clamping kept, by cooling both the cavity 3 and the core 4, a cooling time can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for heating and cooling a mold and a method for heating and cooling the same.

[0002]

2. Description of the Related Art In an apparatus for injection molding a resin such as plastic, in order to maintain good quality of a molded article,
It is important to control the temperature of the mold. Particularly, the molding surface of the mold before injection molding is heated in advance, and the mold is cooled immediately after molding. Conventionally, (1) as a device for directly heating or directly cooling a mold cavity surface or a core surface,
The technique described in JP-A-9-104048 is known. This one sandwiches the cavity insert separated from the mold body by the moving mechanism with a pair of external heating means,
The mold, the cavity surface and its back surface are directly heated before molding, and after heating, the cavity insert is assembled to the mold body,
Close the mold and inject the resin. Then, at the time of injection, cooling water is caused to flow through the cooling holes of the mold body to cool the back surface of the mold cavity surface. (2) Also, in Japanese Patent Publication No. 60-56604,
By interposing a heating source (an inductor in a high-frequency oscillator) between the cavity and the core, the cavity surface and the core surface are simultaneously heated, and water is passed through the mold with the mold closed, so that the cavity surface is heated. And a core surface are simultaneously cooled.

[0003]

However, in the technique (1), since the core surface cannot be heated, the temperature difference between the heated cavity surface and the core surface becomes large, and the molded product cannot be heated. There have been problems such as warpage and sink marks, and poor molding phenomena such as poor transfer.
In addition, to use a heating source processed into the shape of the molded product,
When the molded article is complicated, the heat source also needs to be processed into a complicated shape, and the processing is troublesome and causes an increase in cost. Further, it is practically difficult to accurately arrange a heating source having a complicated shape close to the cavity surface (a separation distance of about 0.2 mm), and there is a concern that the cavity surface may be damaged. In the technique (2), the cavity surface and the core surface can be heated and cooled at the same time. However, since the entire mold is heated and cooled, the heat capacity is increased, and the heating and cooling time is prolonged. In addition, the shape of the heating source must be formed and processed in accordance with the cavity surface, and the same disadvantages as in the technique (1) occur.

Accordingly, it is an object of the present invention to efficiently heat and cool both the cavity portion and the core portion in a short time, and to eliminate various molding defects caused by defective filling and defective transfer. Another object of the present invention is to provide a heating and cooling device for a mold and a heating and cooling method therefor, which can improve molding quality.

[0005]

In order to achieve the above object, a mold heating apparatus according to the first aspect of the present invention comprises:
A mold heating device for heating a mold comprising a core and a core that can be opened and closed to form a resin molding space in a mold-clamped state, and a pressing movable body that presses the core and presses against the cavity during mold clamping. A fixed pressure receiving body that receives a pressing force acting on the cavity by contacting the core with which the core is pressed, a core separating unit that separates the core from the pressing movable body when the mold is opened, and a Cavity separation means for separating the cavity from the fixed pressure receiving body, and a heating means for simultaneously heating both the core separated from the pressing movable body and the cavity separated from the fixed pressure receiving body when the mold is opened. It is characterized by having. In this means, the core is heated in a state where there is no heat transfer between the pressing movable body and the pressing movable body, and the heat transfer between the fixed pressure receiving body and the fixed pressure receiving body is separated. Since the cavity is heated in a state where there is no heat, both the core and the cavity having a small heat capacity are heated, the amount of heat required for heating is reduced, and the core and the cavity can be heated to the target temperature in a short time.

In the mold heating means, the heating means heats both the cavity and the core by irradiation of light, a steam heater, or radiant heat generated by itself. ), When the heat is transmitted using a fluid as a medium, such as a hot air blowing device (Claim 3), the core surface of the core and the cavity surface of the cavity can be directly heated, and the temperature increases. Time can be further reduced. Further, there is no fear of damaging the core surface and the cavity surface during heating. The heating means according to the second and third aspects is inserted between the cavity and the core when the mold is opened, and directly heats both the cavity surface and the core surface in contact with the molding resin, thereby shortening the heating time. In addition, by simultaneously heating the cavity surface and the core surface, both can be easily heated to substantially the same temperature. Further, the heating of the cavity surface and the core surface may be performed by the same heating means, but may be performed by different heating means. According to a fourth aspect of the present invention, in the mold heating apparatus of the first aspect, the heating means is a heater embedded in the cavity and the core. It is preferable to arrange the heater near the cavity surface and the core surface in order to shorten the heating time.

According to a fifth aspect of the present invention, there is provided a mold cooling apparatus for cooling a mold including a core and a core which can be opened and closed to form a resin molding space in a closed state. A pressing movable body that presses the core and presses against the cavity, a fixed pressure receiving body that receives a pressing force acting on the cavity when the core comes into contact with the pressed cavity, and the pressing movable body that opens when the mold is opened. Core separation means for separating the core from the body, cavity separation means for separating the cavity from the fixed pressure receiving body at the time of mold opening, and cooling means provided in each of the pressing movable body and the fixed pressure receiving body, With the mold closed,
Heat conduction is performed from the core to the pressing movable body in which the contact state with the core is maintained, and heat conduction is performed from the cavity to the fixed pressure receiving body in which the contact state with the cavity is maintained. , And the core and the cavity are each cooled by the cooling means. This means relates to a technique of cooling the core and the cavity in a mold-clamped state, and cooling and solidifying the molded resin after being injected into the mold, from the back side facing the core surface of the core that comes into contact with the molded resin. The core surface is cooled by heat conduction to the pressing movable body abutted thereon, and the cavity is cooled by heat conduction from the cavity surface of the cavity in contact with the molding resin to the fixed pressure receiving body abutted thereon. Heat conduction from the core and the cavity to the pressing movable body and the fixed pressure receiving body is started at the same time as the mold clamping, and almost simultaneously with the completion of the resin molding in the mold, the temperature of the core surface and the cavity surface starts decreasing. The core surface and the cavity surface are more preferably located near the pressing movable body and the fixed pressure receiving body, so that the core surface and the cavity surface can be cooled more efficiently. Both water flow to the core and water flow to the pressing movable body can be used in combination, and water flow to the cavity and water flow to the fixed pressure receiving body can be used in combination. When the mold is opened from the clamped state, the pressing movable body and the core are separated by the core separating member, and the fixed pressure receiving body and the cavity are separated by the cavity separating member. can do.

According to a sixth aspect of the present invention, there is provided a mold cooling apparatus for cooling a mold comprising a cavity and a core which can be opened and closed to form a resin molding space in a closed state. A pressing movable body that presses the core and presses against the cavity, a fixed pressure receiving body that receives a pressing force acting on the cavity by contacting the cavity where the core presses, and the core when the mold is opened. A core separating means for separating the pressing movable body, a cavity separating means for separating the fixed pressure receiving body from the cavity when the mold is opened, and a through-hole provided in at least one of the core or the pressing movable body and at least one of the cavity or the fixed pressure receiving body. Cooling means by water, and in a mold clamped state, water is passed through the core or the pressing movable body in a contact state with the core to thereby cool the core. It was cooled, and is characterized by cooling the cavity to the cavity or the cavity by passing water to the fixed pressure receiving body contact state. When water is directly passed through the core and the cavity, the core and the cavity can be cooled in a short time. When water passes through the pressing movable body and the fixed pressure receiving body, the core,
Cool the cavity indirectly. When the mold is opened from the clamped state, the pressing movable body and the core are separated by the core separating member, and the fixed pressure receiving body and the cavity are separated by the cavity separating member. can do.

[0009] In a method of heating a mold according to a seventh aspect of the present invention, in the method of heating a mold comprising a core and an openable cavity forming a resin molding space in a clamped state and a core, the method includes the steps of: Along with separating the cavity and the core, a pressing movable body for pressing the core against the cavity and pressing the core is separated from the core,
And, after separating the fixed pressure receiving body which receives the pressing force acting on the cavity when the core is pressed against the cavity from the cavity, both the cavity and the core are heated by heating means. And In this means, the core is heated in a state where the core is separated from the pressing movable body and there is no heat transfer between the pressing movable body and the core is separated from the fixed pressure receiving body, and the heat between the core and the fixed pressure receiving body is heated. Since the cavity is heated without any movement,
In both cases, the core and the cavity having small heat capacities are heated, so that the amount of heat required for heating is reduced, and the core and the cavity can be heated to the target temperature in a short time.

In the method for cooling a mold according to the present invention, when the mold is opened, the mold is separated from the fixed pressure receiving body and the pressing movable body. In a mold cooling method for cooling a mold comprising an openable and closable cavity and a core which are in contact with each other to form a resin molding space, after the completion of resin molding,
Cooling means provided to the pressing movable body through heat conduction from the core to the pressing movable body that contacts the core and presses the cavity while maintaining the mold-clamped state of the cavity and the core. Cooling, and cooling the cavity by cooling means provided in the fixed pressure receiving body via heat conduction from the cavity to a fixed pressure receiving body that abuts on the cavity and receives a pressing force from the core. Features. In this cooling method, at the same time as the mold clamping, cooling of the core and the cavity is started by heat conduction to the pressing movable body abutting on the core and heat conduction to the fixed pressure receiving body abutting on the cavity, Almost simultaneously with the completion of the resin molding in the mold, the cooling of the core surface and the cavity surface is started.

According to a ninth aspect of the present invention, in the method for cooling a mold, the mold is separated from the fixed pressure receiving body and the pressing movable body when the mold is opened, and is brought into contact with the fixed pressure receiving body and the pressing movable body when the mold is closed. In a mold cooling method for cooling a mold comprising an openable and closable cavity and a core which are in contact with each other to form a resin molding space, after the completion of resin molding,
The mold and the cavity are maintained in a clamped state, and the core and the cavity are cooled by direct water flow. In this cooling method, the cooling method described in claim 8 can be used in combination, whereby the core and the cavity can be cooled in a shorter time.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings, embodied in an injection mold. In FIG. 1, reference numeral 1 denotes a fixed platen-side main die, 2 denotes a movable platen-side main die, 3 denotes a cavity, and 4 denotes a core. These components mainly constitute an injection mold. Fixed type 1
Functions as a fixed pressure receiving member that receives a pressing force acting on the cavity 3 at the time of mold clamping, and is fixed to a fixed plate of the injection molding machine by a bolt or the like via the flange 1a. The movable platen-side main die 2 functions as a pressing movable body that presses the core 4 and presses against the cavity 3 at the time of mold clamping, and is fixed to the movable plate of the injection molding machine by bolts or the like via the flange 2a. , Is provided opposite to the fixed platen-side main mold 1. By a moving mechanism not shown,
When the movable platen is moved and the movable platen-side main mold 2 moves linearly toward the fixed platen-side main mold 1, the core 4 is pressed and pressed against the cavity 3 supported on the fixed platen side (the right side in FIG. 1). Then, a molding space is formed between the cavity 3 and the core 4. Conversely, when the movable platen-side main die 2 retreats with respect to the fixed platen-side main die 2, the core 4 is separated from the cavity 3. The mold is opened.

The cavity 3 is provided with a molding recess 3 a forming a molding space on the front side facing the core 4, and has an annular heat insulating plate 5 having a rear surface fixed to the center of the cavity support plate 5.
a, and is fixed to the cavity support plate 5 with bolts or the like. The cavity support plate 5 is fixed by a plurality of guide pins 6 (only one is shown in FIG. 1 and others are omitted) protruding from the fixed platen-side main die 1 to the movable platen-side main die 2. It is supported so as to be able to move forward and backward with respect to the board-side main mold 1 and at a variable distance from the fixed board-side main mold 1. A spring 7 externally fitted to the guide pin 6 is interposed between the fixed platen-side main mold 1 and the cavity support plate 5, and when the mold is opened as shown in FIG. The plate 5 is moved away from the fixed platen-side main mold 1, and the front surface of the cavity support plate 5 comes into contact with a head 6a provided at the free end of the guide pin 6, so that the movement is stopped. . A hole 5b is formed in the center of the cavity support plate 5. At the time of mold clamping, a projection 1e provided at the center of the fixed platen main mold 1 is inserted into the hole 5b, and the cavity 3b is formed. And the protrusion 1e are in contact with each other, and an injection hole 3c formed in the center of the cavity 3 so as to penetrate the molding recess 3a; 1b communicates with each other, and molding resin is injected from the sprue 1c into the molding space formed by the cavity 3 and the core 4 through the runner 1b and the injection hole 3c.

On the other hand, on the side of the core 4 facing the cavity 3, a core portion 4b is formed, which is fitted into the molding recess 3a of the cavity 3 and has a core surface 4a constituting one surface of the molding space. The surface opposite to the cavity 3 is brought into contact with an annular heat insulating plate 8a fixed to the center of the core supporting plate 8,
It is fixed to the core support plate 8 by bolts or the like. The core support plate 8 is movable by a plurality of guide pins 9 (only one is shown in FIG. 1 and the others are omitted) protruding from the movable platen-side main die 2 to the fixed platen-side main die 1. It is supported so as to be able to move forward and backward with respect to the board-side main mold 2 and at a variable distance from the movable board-side main mold 2. Further, a spring 10 externally fitted to the guide pin 9 is interposed between the movable platen-side main mold 2 and the core support plate 8, and when the mold shown in FIG. The plate 8 is moved away from the movable platen-side main die 2, and the core support plate 8 comes into contact with the head 9a on the free end side of the guide pin 9, so that the movement is stopped.

A hole 8b is formed in the center of the core support plate 8, and a projection is formed in the hole 8b at the center of the movable platen-side main mold 2 toward the cavity 3 when the mold is clamped. 2b is inserted so that the surface of the protrusion 2b facing the core 4 and the surface of the core 4 facing the protrusion 2b come into contact with each other. In FIG. 1, reference numeral 11 denotes an ejector pin fixed to the pressing plate 11a, which is inserted into a pin hole provided in the movable platen-side main die 2 and the core 4, moves forward and backward toward the cavity 3, and By protruding from the surface 4a, the molded product is protruded. Further, the movable platen side main die 2 has a plurality of guide pins 12 protruding toward the cavity support plate 5 penetrating the core support plate 8 at a plurality of positions (only one is shown in FIG. 1) on the outer side thereof. The guide pins 12 are inserted into guide pin holes 13a and 13b formed at a plurality of positions (only one is shown in FIG. 1) on the outer side of the fixed platen main mold 1 and the cavity support plate 5 at the time of mold clamping. The cavity support plate 5 is guided by being fitted so that the core 4 and the cavity 3 are not displaced from each other in a direction orthogonal to the mold clamping direction. Further, a cooling water hole 1d is provided in the fixed platen-side main mold 1, and a cooling water hole
c are formed, and after completion of molding, cooling water is circulated.

A heating means 14 for directly heating the cavity surface 3b and the core surface 4a of the mold is connected to a rod 15a of an actuator (moving / retracting means) 15 such as a hydraulic cylinder. In the middle position between the mold and the core 4, it is provided so as to move forward and backward between a position facing the cavity surface 3 b and the core surface 4 a and a retracted position separated upward or to the side of the mold. The heating means 14
Heating both the cavity and the core by radiant heat generated by itself, such as irradiation of heating light, a steam heater, or a ceramic heater, a heater that generates heat by electric resistance or high-frequency induction, or the like, or A device that transfers heat using a fluid as a medium, such as an air blowing device, is used. In both cases, the flat heating surfaces are parallel to the opposing surfaces of the cavity 3 and the core 4 and are the molding surfaces of the cavity 3. Both the cavity surface 3b and the core surface 4a which is the molding surface of the core 4 are directly heated simultaneously. As a heating means by irradiation of the heating light, for example,
A halogen lamp 14a (see FIG. 2), an infrared lamp, or the like is employed. The reciprocating means 15 is installed on a base or other parts of the injection molding machine by a support member (not shown),
Alternatively, it is attached to a column or the like installed on the floor near the injection molding machine. The advance / retreat means 15 may be constituted by a manipulator, an industrial robot, or the like installed near the injection molding machine.

Next, a method for heating a mold and a method for cooling a mold according to the present invention, which are carried out using the above-described apparatus, will be described with reference to the operation flowchart of FIG. In order to perform injection molding of a resin such as plastic using the injection mold, first, the mold is opened (step 21), and a heating source (heating means 14) is inserted between the cavity 3 and the core 4 (step 21). 22),
Heating is performed (step 23). The heating is performed while confirming the temperature rise (step 24), and is completed when it is confirmed that the temperature has been raised to the target temperature (step 25). Thereby, the cavity surface 3 of the cavity 3 is formed before the injection molding.
b, the core surface 4a of the core 4 is heated to a target temperature.

In the above, when the movable platen-side main die 2 moves away from the fixed platen-side main die 1 to open the mold,
The cavity support plate 5 is moved away from the fixed platen-side main die 1 and the core support plate 8 is moved away from the movable platen-side main die 2 by the urging forces of the springs 7 and 10 compressed when the mold is closed. Move along the guide pins 6 and 9, respectively, the cavity 3 and the core 4, which have been in contact with the fixed platen main mold 1 and the movable platen main mold 2 via the protrusions 1e and 2b, respectively, make the contact. After being cut off, cavity 3 and core 4
Are released from each other, and a predetermined space is formed between them. At this time, as shown in FIG. 1, heating by the heating means 14 is performed by the biasing force of the springs 7 and 10, whereby the movable platen-side main mold 2 is separated from the core 4 and the fixed plate-side main mold 1 is separated from the cavity 3. Is performed in a separated state. Moreover, the cavity 3 and the core 4 are attached to the cavity supporting plate 5 and the core supporting plate 8 via the heat insulating plates 5a and 8a, and are not in direct contact with them. Accordingly, heat transfer to the cavity support plate 5 and the core support plate 8 is suppressed as much as possible. Thus, the heating means 14 heats only the cavity 3 and the core 4 having a small heat capacity, and does not heat the main dies 1 and 2 on the fixed plate side and the movable platen side. It can be heated quickly in a short time. Also,
Since both the cavity surface 3b and the core surface 4a are heated at the same time, both can be heated substantially evenly, and inconveniences such as warpage, sink mark, transfer failure, etc., which occur in a molded product due to a difference in temperature can be prevented, and the molding quality can be improved. The effect that it can improve is acquired. At this time, the spring 7 functions as cavity separating means, and the spring 10 functions as core separating means.

As shown in FIG. 5, when heating of the cavity surface 3b and the core surface 4a is completed, a heating source (heating means 14)
Is pulled out from the cavity 3 and the core 4 by the reciprocating means 15 and retracted (step 26), the mold is closed and the mold is closed, and the resin is injected (steps 27 and 2).
8).

The mold closing and closing operations of the injection molding die will be described in detail with reference to FIGS. 1 and 3. First, the movable platen-side main die 2 is advanced toward the fixed platen-side main die 1. When the core 4 comes into contact with the cavity 3 and presses it, the cavity 3 is moved by the spring 7 through the cavity support plate 5.
Is moved together with the cavity support plate 5 in the direction of the fixed platen main die 1 while pressing, and the fixed platen main die 1 is moved into the cavity through the protrusion 1e fitted into the hole 5b formed in the cavity support plate 5. When it comes into contact with the back surface of the cavity 3, the movement of the cavity 3 stops. At the same time as the above operation, the same operation is performed on the movable platen side, and the core 4 abutting on the cavity 2 compresses the spring 10 via the core supporting portion 8 to relatively move the core 10 on the movable platen side. While approaching the mold 2, it moves closer to the fixed platen main die 1 together with the movable platen main die 2, and in the process, the holes 8b formed in the core support plate 8 are formed.
, The protruding portion 2b of the movable platen-side main die 2 is inserted, and the end face thereof is pressed against the back surface of the core 4, and finally, the cavity is formed between the fixed-side main die 1 and the movable platen-side main die 2. The core 3 and the core 4 are sandwiched and brought into a state of being securely pressed, and the mold clamping is completed. Therefore, after the heating means 14 is retracted to the outside position of the mold by the advancing / retracting means 15 and then the mold is clamped, the fixed plate side main mold 1 comes into contact with the cavity 3 and the core 4
The movable platen-side main mold 2 is brought into contact with the mold, and the transition from heating of the cavity surface 3b and the core surface 4a to mold clamping is smoothly performed in a short time, so that the high temperature of the cavity surface 3b and the core surface 4a is maintained. The process can be shifted to the injection step, and inconveniences such as defective filling of the molding resin and defective transfer can be reliably prevented.

Returning to FIG. 5, the description will be continued. In step 28, the cooling water holes 1d, 2c
Cooling water is passed through (see FIG. 1) to cool the fixed platen-side main die 1 and the movable platen-side main die 2. The fixed platen-side main die 1 and the movable platen-side main die 2 are both formed of a material such as steel having excellent heat conductivity.
, The cavity 3 is cooled by heat conduction from the fixed platen-side main mold 1, and the movable platen-side main mold 2 is cooled.
The core 4 is cooled by the heat conduction from the core 4. Cooling water hole 1
The water flow to d and 2c is started simultaneously with mold clamping because the cavity 3 and the core 4 are indirectly cooled via the fixed platen main mold 1 and the movable platen main mold 2, respectively. At the same time as the completion, the temperatures of the cavity surface 3b and the core surface 4a are lowered.

When the cooling of the cavity 3 and the core 4 is completed, the molded product is taken out of the mold (step 29). That is, as shown in FIG. 4, the movable platen-side main die 2 is moved in a direction away from the fixed platen-side main die 1 to open the mold, and the pressing plate 1 is moved by ejector driving means (not shown).
1a in the direction of the fixed platen main mold 1, and ejector pin 1
1 is operated, and the molded product 16 attached to the core 4 of the opened mold is ejected by the ejector pin 11. When the molding cycle is completed (step 30), the operation of the entire apparatus shifts to a state where it can be stopped, and when the next molding is to be performed, the process returns to step 22, and thereafter steps 23 to 30 are executed. At the same time as the mold is opened in step 29, the cavities 3 are separated from the fixed platen-side main die 1 by the springs 7 and 10 and the core 4 is separated from the movable platen-side main die 2, so that the process proceeds from step 30 to step 22 Is a heating source (heating means 1) between the cavity 3 and the core 4.
4) It only needs to be inserted, and is performed quickly.

Further, in this injection molding die, as a method of heating the cavity surface 3b and the core surface 4a, a planar heating plate (heating means) composed of a heating source for heating the object to be heated by radiant heat generated by the heat generated by itself. May be sandwiched between the cavity 3 and the core 4 so as to be brought into direct contact therewith. This heating method will be described with reference to the operation flowchart of the injection mold shown in FIG. First, the mold is opened (step 31), and the cavity 3 and the core 4 are opened.
(Step 3)
2) After that, the mold is closed until the cavity 3 and the core 4 come into contact with the heating plate (step 33). Next, the cavity surface 3b and the core 4a are heated by the heating plate (step 34). When it is confirmed that the temperature has been raised to the target temperature (step 35), the heating is terminated (step 36), and the mold is heated. Open until it leaves the board (step 37),
The heating plate is pulled out from between the cavity 3 and the core 4 (step 38).

Next, the cavity 3 and the core 4 are closed.
After the mold is clamped (step 39), the molding resin is injected into the mold, and then cooling water is flowed through the fixed platen-side main die 1 and the movable platen-side main die 2 to inject and cool the molded product (step 40). When the cooling is completed, the molded product is taken out (step 41).
In the cooling in step 40, since the fixed platen side and the movable platen side main molds 1 and 2 are cooled by the flow of water to the cooling water holes 1d and 2c, heat conduction from the cavity 3 to the fixed platen side main mold 1 is performed. Heat transfer from the core 4 to the movable platen-side main mold 2 cools the cavity 3 and the core 4 that are in contact with the fixed platen-side, movable platen-side main molds 1 and 2 when the mold is closed. The water flow to the cooling water holes 1d and 2c starts at the same time as the mold clamping, and at the same time as the injection of the molding resin is completed, the cavity surface 3b and the core surface 4b.
The temperature of a is lowered. When the removal of the molded article is completed, it is selected whether or not to end the cycle (step 42).
Then, steps 33 to 42 are executed.

Next, a second embodiment of a mold heating / cooling apparatus according to the present invention, which is embodied in an injection molding mold, will be described with reference to FIG. As shown in FIG. 7, the cavity 51 applied to the injection molding die is placed close to the cavity surface 51b which constitutes one surface of the molding recess 51a, and the heating wire or the like extends over the cash machine of the cavity surface 51b. A heater (heating means) 52 is formed by meandering the cooling water, and a cooling water hole 53 for circulating cooling water over substantially the entire area of the cavity 5 is formed. Similarly, a heater 55 as a heating means is also provided in the core 54 in the vicinity of the core portion 54b so that the cooling water hole 5 is provided.
6 are provided over substantially the entire area of the core 54. The other parts of the injection mold are configured in the same manner as in the first embodiment, and therefore, are denoted by the same reference numerals as those in the first embodiment, and description thereof is omitted.

Next, a method for heating the mold and a method for cooling the mold, which are performed by using the apparatus according to the second embodiment of the present invention, will be described with reference to the operation flowchart of FIG. In order to obtain a molded product using this injection mold, first, after opening the mold (step 61), the heaters 52 and 55 are turned on to start heating the cavity 51 and the core 54, and the target temperature is confirmed. (Steps 62, 63, 6)
4). At this time, as shown in FIG. 7, the cavity 51 is separated from the fixed platen-side main die 1 by the spring 7, and the core 54 is also separated from the movable platen-side main die 2 by the spring 10, so that the heater 52 has a small heat capacity. Cavity 5
1. The core 54 is heated, and this heating is efficiently performed in a short time. Moreover, the heater 52 is brought close to the cavity surface 51b which is the molding surface of the cavity 51,
Since the heater 55 is close to the core surface 54a which is the molding surface of the core 54, the cavity surface 51b, the core surface 54
a is rapidly heated in a short time.

When the temperature rise is completed, the heating is terminated, the heaters 52 and 55 are turned off (step 65), the mold is closed and the mold is closed, and the molding resin is injected (steps 66 and 6).
7). At this time, only by clamping the mold, the fixed platen-side main die 1 abuts against the cavity 51, and the movable platen-side main die 2 abuts against the core 54, so that the heating of the cavity surface 51b and the core surface 54a from the clamping to the mold clamping is performed. Since the transition is performed smoothly in a short time, it is possible to proceed to the injection step while maintaining the high temperature of the cavity surface 51b and the core surface 54a, and it is possible to reliably prevent inconveniences such as molding resin filling failure and transfer failure.

When the injection is started, water is passed through the cooling water holes 1d and 2c to start cooling the fixed platen-side and movable platen-side main dies 1 and 2,
When the injection is completed or near completion, the cooling water hole 5
3, 56, and the cavity 51 and the core 54
Is cooled (steps 68 and 69). Thus, not only the fixed platen-side and movable platen-side main dies 1 and 2 but also the cavity 51 is formed.
The core 54 and the core 54 are also cooled by direct water flow, so that the cavity surface 51b and the core surface 54a are cooled in a shorter time than the injection molding die of the first embodiment.
When the cooling at the target temperature at which the injection resin is solidified is completed, the mold is opened and the molded product is taken out (steps 70 and 71). Then, it is selected whether or not to end the cycle (step 72). If the cycle is to be continued, the process returns to step 62, and thereafter, steps 63 to 72 are executed to perform the next molding. At the same time as the mold is opened in step 70, the cavities 51 are separated from the fixed platen-side main die 1 by the springs 7 and 10, and the core 54 is separated from the movable platen-side main die 2. Is only required to turn on the heaters 52 and 55, and the operation is quickly performed.

As described in each of the above embodiments,
In the heating device and the heating method according to the present invention, the cavities 3, 51, and the cores 2, 54 having a small heat capacity are heated by the heating means in a state where the cavities 3, 51 and the cores 2, 54 are separated from the fixed platen side and the movable platen side main dies 1, 2. Cavity surfaces 3b, 51b, core surfaces 4a, 54
a can be efficiently raised to the target temperature in a short time. Moreover, the cavity surfaces 3b, 51b, the core surface 4
a, 54a can be easily heated uniformly, and the molding quality can be improved. Further, the amount of heat required for heating can be reduced, and the cost can be reduced.

FIG. 9 shows the results of comparison of the temperature rise of the mold when the injection mold is heated in a state where it is separated into the main mold, the cavity and the core, and when it is heated without being separated. . In FIG. 9, a solid line (mold separation) is a temperature rise curve of the cavity by the heating method according to the present invention, and a broken line (mold contact) is a temperature rise curve of the cavity by the heating method without separating from the fixed platen main die. In each heating method, the mold is opened and heating is performed using heating means having six 1.2 kW heaters inserted between the cavity and the core. The cavity has a size of 300mm x 400m
It is a steel plate of mx 45 mm. As shown in FIG. 9, it can be seen that the heating method according to the present invention can rapidly raise the temperature of the cavity in a short time.

FIG. 10 shows a temperature rise curve of a steel sheet heated by a halogen lamp. The halogen lamp is 500W,
The steel plate size is 90 mm × 90 mm × 1.2 mm, and the distance between the halogen lamp and the steel plate is 10 mm. This FIG.
As can be seen from this halogen lamp, in 31 seconds,
The temperature of the steel sheet can be raised to 100 ° C., and the cavity and core made of steel or the like can be similarly heated in a short time.

Table 1 shows combinations of methods for heating and cooling the cavity and the core. In Table 1, "heater heating" refers to heating by a heater built in the cavity and the core, whereas "external heating" refers to heating outside the cavity and the core by the heating means 14 or the like shown in FIG. Refers to heating by various heating means arranged. Further, “water cooling” refers to cooling by water flowing into cooling water holes formed in the cavity and the core, and “indirect cooling” refers to cooling by heat conduction to the main mold in contact with the cavity and the core. As shown in Table 1, a plurality of combinations of the heating method and the cooling method can be considered, and any of them can be adopted.

[0033]

[Table 1]

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the pressing movable body that presses the cores 4 and 54 and the fixed pressure receiving body that receives the pressure of the cavities 3 and 51 are not limited to the structure of the movable platen-side main die 2 or the fixed platen-side main die 1. Can be adopted. Separation means for separating the cavity from the fixed pressure receiver,
The separating means for separating the core from the pressing movable body is not limited to a spring, and various configurations such as those utilizing magnetic repulsion can be adopted.

[0035]

As described above, according to the present invention,
Since the cavity and core are heated while the core is separated from the pressing movable body and the cavity is separated from the fixed pressure receiving body, the cavity and the core having a small heat capacity are heated. Heating can be performed efficiently. In addition, since the cavity and the core are heated at the same time, a decrease in molding quality due to a difference in temperature can be prevented, and a high molding quality can be stably obtained. In addition, since the cavity and the core can be cooled simultaneously in a short time, both the cavity and the core can be simultaneously cooled, so that high molding quality can be stably obtained, and the molding time can be reduced. It has an excellent effect that the production efficiency of the product can be improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a mold heating device according to a first embodiment of the present invention.

FIG. 2 is a front view showing a halogen lamp as a heating unit applied to FIG.

FIG. 3 is a front view showing a closed state of the injection mold of FIG. 1;

FIG. 4 is a front view showing removal of a molded product from the injection mold of FIG. 1;

FIG. 5 is a flowchart showing a molding operation of the injection mold of FIG. 1;

6 is a flowchart showing a molding operation in a case where a heating means is interposed between a cavity and a core of the injection mold of FIG. 1 to heat the cavity and the core.

FIG. 7 is a front view showing an injection mold according to a second embodiment of the present invention.

FIG. 8 is a flowchart showing a molding operation of the injection mold of FIG. 7;

FIG. 9 is a graph showing an effect of the present invention, and is a graph showing a comparison of a heating time of a mold with a conventional example.

FIG. 10 is a graph showing a temperature rise curve when a steel sheet is heated by a halogen lamp.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixed pressure receiving body (fixed board side main type), 2 ... Press movable body (movable board side main type), 3 ... Cavity, 4 ... Core, 7 ... Cavity separation means (spring), 10 ... Core separation means (Spring) ), 14 ... heating means, 14a ... heating means (halogen lamp), 53 ... heating means (heater).

Claims (9)

[Claims] 1. A mold heating apparatus for heating a mold comprising a core and a core which can be freely opened and closed to form a resin molding space in a mold clamped state, wherein the mold is pressed against the cavity when the mold is clamped. A pressing movable body to be pressed, a fixed pressure receiving body that receives a pressing force acting on the cavity by abutting the core against which the core is pressed, and a core separating unit that separates the core from the pressing movable body when the mold is opened. A cavity separating means for separating the cavity from the fixed pressure receiving body when the mold is opened, and simultaneously heating both the core separated from the pressing movable body and the cavity separated from the fixed pressure receiving body when the mold is opened. And a heating means for heating the mold. 2. The heating device according to claim 1, wherein the heating unit heats both the cavity and the core by radiating heat generated by irradiation of a heating light, a steam heater, or heat generated by the heating unit. Mold heating equipment. 3. The mold heating apparatus according to claim 1, wherein said heating means transmits heat using a fluid as a medium, such as a hot air blowing apparatus. 4. The mold heating apparatus according to claim 1, wherein said heating means is a heater embedded in each of said cavity and said core. 5. A mold cooling device for cooling a mold comprising an openable and closable cavity and a core forming a resin molding space in a mold clamped state, wherein the mold is pressed against the cavity by pressing the core during mold clamping. A pressing movable body to be pressed, a fixed pressure receiving body that receives a pressing force acting on the cavity by abutting the core against which the core is pressed, and a core separating unit that separates the core from the pressing movable body when the mold is opened. And a cavity separating means for separating the cavity from the fixed pressure receiving body when the mold is opened, and cooling means provided on each of the pressing movable body and the fixed pressure receiving body. Heat conduction to the pressing movable body maintained in contact with the core, and transfer from the cavity to the fixed pressure receiving body maintained in contact with the cavity. Conduction is performed, the mold core and cavity, characterized in that is adapted to be cooled, respectively by said cooling means cooling device. 6. A mold cooling device for cooling a mold comprising an openable and closable cavity and a core forming a resin molding space in a mold clamped state, wherein the mold is pressed against the cavity by pressing the core during mold clamping. A pressing movable body to be pressed, a fixed pressure receiving body that receives a pressing force acting on the cavity by contacting the core against which the core is pressed, and a core separating unit that separates the pressing movable body from the core when the mold is opened. And a cavity separating means for separating the fixed pressure receiving body from the cavity when the mold is opened, and cooling means for supplying water to at least one of the core or the pressing movable body and at least one of the cavity or the fixed pressure receiving body. In this state, the core is cooled by passing water through the core or a pressing movable body in contact with the core, and Or mold cooling apparatus characterized by cooling the cavity to the cavity by passing water to the fixed pressure receiving body contact state. 7. A mold heating method for heating a mold comprising an openable and closable cavity and a core forming a resin molding space in a mold-clamped state, wherein the cavity and the core are separated as the mold is opened. A fixed pressure receiving body that separates a pressing movable body for pressing the core against the cavity and pressing the core from the core, and that receives a pressing force acting on the cavity when the core is pressed against the cavity. A method for heating a mold, comprising heating both the cavity and the core by a heating unit after separating from the cavity. 8. The fixed pressure receiving body and the pressing movable body are separated from each other when the mold is opened, and when the mold is clamped, the fixed pressure receiving body and the pressing movable body are respectively brought into contact with each other. A method of cooling a mold comprising a mold having an openable / closable cavity and a core, wherein the mold and the cavity are maintained in a closed state after completion of resin molding. The core is cooled by cooling means provided on the pressing movable body through heat conduction to the pressing movable body which comes into contact with and presses against the cavity, and the pressing force from the core is received from the cavity by contacting the cavity with the cavity. And cooling the cavity by cooling means provided on the fixed pressure receiving body through heat conduction to the fixed pressure receiving body. 9. The fixed pressure receiving body and the pressing movable body are separated from each other when the mold is opened, and when the mold is clamped, the fixed pressure receiving body and the pressing movable body are respectively brought into contact with each other. In a mold cooling method for cooling a mold comprising an openable and closable cavity and a core to be formed, after completion of resin molding, the mold and the cavity are maintained in a closed state, and the core and the cavity are directly passed through. A mold cooling method characterized by cooling with water.