JPH09104048A - Apparatus and method for heating and heating/cooling mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heating efficiency by specially separating the rear surface of a core from a mold main body at a time of mold opening and heating the molding surface of the core by an external heating means in an almost thermally insulated state. SOLUTION: At a time of mold opening, a predetermined space is formed between the rear surface of a cavity core 26 and a fixed back surface 23 by a cavity core means 24. A first external heating means 31 is allowed to advance to the position coming into contact with the rear surface of the cavity core 26 by a first moving mechanism 41 and a cavity surface is heated through the rear surface by the heat conductivity from a hot plate. A second external heating means 32 is allowed to advance to the position approaching and opposed to the cavity surface at a predetermined interval by a second moving mechanism 42 and the cavity surface is heated by the heat radiation from a hot plate. At a time of mold clamping, the rear surface of the cavity core 26 is brought into contact with the fixed back plate 23 having a cooling means to cool the cavity surface through the rear surface. First and second external heating means 31, 32 are allowed to retreat to a position interfering the cavity core 26 by the first and second moving mechanisms 41, 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold heating device, a heating / cooling device and a method therefor, and more particularly, to preheating a molding surface of a mold before injection molding to improve the quality of an injection molded product. The present invention relates to an apparatus and a method capable of improving and the like.

[0002]

2. Description of the Related Art It is generally known that when a resin is injected with the cavity surface of a resin molding die being heated, the appearance quality and optical characteristics of the molded product are improved. As a conventional heating device for this type of mold, Japanese Patent Publication No. 60-56604 and Japanese Patent Laid-Open No. 62-17991.
No. 2, JP-A-62-111832, JP-A-6-6
3-15707, JP-A-62-208918, JP-A-58-12714, or JP-A-58.
The technology disclosed in Japanese Patent Publication No. 211405 can be mentioned. For example, the technology of Japanese Patent Publication No. 60-56604 is
Resin is injected with the cavity surface temperature raised in advance by high-frequency induction heating. Incidentally, JP-A-62-111
No. 832 and Japanese Patent Laid-Open No. 63-15707 disclose similar techniques. Also, JP-A-62-1799
In the technique disclosed in Japanese Patent No. 12, a heating medium such as hot water or hot oil and a cooling medium are alternately passed through a flow path in the mold to raise or lower the cavity temperature. Incidentally, JP-A-62-208918, JP-A-58-12714 and JP-A-58-208
Japanese Patent No. 211405 discloses a similar technique. Other techniques of this kind include active heating of the cavity surface of the die by Joule heating, a heater built into the die, or SSI (spotless surface injection) molding. There is a method of passively heating the cavity surface by injection molten resin.

[0003]

[Problems to be solved by the invention]
Since the technique of Japanese Patent No. 56604 utilizes high-frequency induction heating, a high-frequency generator such as a high-frequency oscillator is required, which increases equipment costs. Further, in general, it is necessary to raise the cavity surface temperature above the heat deformation temperature of the resin which is the molding material, but the technique of Japanese Patent Laid-Open No. 62-179912 discloses that the temperature of the heating medium is low and the heating performance is low. May be inadequate. That is, special heating methods such as high-frequency induction heating, Joule heating, and SSI molding have high heating performance, but have the drawbacks of increasing equipment costs and lowering maintainability. On the other hand, a general heating method such as heating with a heater built in the mold, or heating with hot water or hot oil flowing inside the mold can reduce the equipment cost as compared with the above special heating method. While good maintainability can be achieved, there is room for improvement in heating performance.

Therefore, a first object of the present invention is to provide a mold heating apparatus and method which have good heating performance, can reduce equipment costs, and can improve maintainability. It is a thing.

Further, the present invention provides a heating and cooling apparatus for a mold and a method thereof, which has a good heating and cooling performance, and which can reduce equipment cost and improve maintainability.
Is the subject of.

[0006]

According to a first aspect of the present invention, there is provided a die heating apparatus, wherein when the die is clamped by the nest moving means,
The back surface of the insert is brought into contact with the mold body, and when the mold is opened, the back surface of the insert is separated from the mold body to form a predetermined space between the back surface of the insert and the mold body. On the other hand, when the mold is closed, the external heating means is retracted to a position where it does not interfere with the insert, and when the mold is opened, it is advanced to a position facing either the molding surface or the back surface of the insert to transfer the molding surface by heat transfer. Heating is performed directly or indirectly via the back surface.

In the mold heating / cooling device according to the second aspect of the present invention, the back of the insert is brought into contact with the mold main body when the mold is clamped by the insert moving means, and the back of the insert is opened when the mold is opened. Is separated from the mold body to form a predetermined space between the back surface of the insert and the mold body. On the other hand, when the mold is closed, the external heating means is retracted to a position where it does not interfere with the insert, and when the mold is opened, it is advanced to a position facing either the molding surface or the back surface of the insert to transfer the molding surface by heat transfer. Directly or
Indirect heating is performed via the back surface. Further, the cooling means provided in the mold body is brought into contact with the back surface of the insert during mold clamping, and the molding surface is cooled via the back surface.

In the mold heating / cooling device according to the third aspect of the present invention, the cavity insert moving means causes the back face of the cavity insert to contact the mold body when the mold is clamped, and the cavity insert is opened when the mold is opened. The back surface of the mold is separated from the mold body to form a predetermined space between the back surface and the mold body. Also, the external heating means is retracted to a position where it does not interfere with the cavity insert during mold closing, and advances to a position where it abuts the back surface of the cavity insert during mold opening, and the cavity surface is transferred through the back surface by heat conduction. To heat. Further, the cooling means provided on the mold body is brought into contact with the back surface of the cavity insert during mold clamping, and the cavity surface is cooled via the back surface.

In the mold heating device according to the invention of claim 4, the cavity insert moving means causes the back face of the cavity insert to contact the mold body when the mold is clamped, and when the mold is opened, the cavity insert moves. The back surface is separated from the mold body to form a predetermined space between the back surface and the mold body. Also, the first external heating means is retracted to a position where it does not interfere with the cavity insert during mold closing, and advances to a position where it abuts against the back surface of the cavity insert during mold opening and heat conduction through the back surface through the back surface. The cavity surface is heated. On the other hand, the second external heating means is retracted to a position where it does not interfere with the cavity insert when the mold is clamped, and when the mold is opened, it is advanced to a position where the cavity face of the cavity insert is close to and opposed to the cavity face with a predetermined gap. The cavity surface is heated by radiation. Further, the cooling means provided on the mold body is brought into contact with the back surface of the cavity insert during mold clamping, and the cavity surface is cooled via the back surface.

According to a fifth aspect of the present invention, there is provided a die heating device according to the fourth aspect, wherein the second external heating means is
It is configured by an electric discharge machining electrode in which the cavity surface of the cavity insert is machined.

According to a sixth aspect of the present invention, there is provided a die heating device according to the fourth aspect, wherein the second external heating means is
When the mold is opened, a first heating surface that closely faces and faces the cavity surface of the cavity insert and a first heating surface that extends and contacts the parting surface of the cavity insert when the mold opens The second heating surface heats the cavity surface via the parting surface by conduction.

According to a seventh aspect of the present invention, in a die heating device according to any one of the first to fourth aspects, the thickness of at least a portion of the insert corresponding to the cavity surface is 0.5 mm. The range is from 15 mm to 15 mm.

In the die heating method according to the invention of claim 8, the back surface of the insert is separated from the die body to form a predetermined space between the back surface and the die body when the die is opened. Next, advance the external heating means as a heat source into the space,
The molding surface is heated via the rear surface by being arranged opposite to the rear surface of the insert.

According to a ninth aspect of the present invention, there is provided a method for heating and cooling a die, wherein the back side of the insert is separated from the die body with the opening of the die to form a predetermined space between the back side and the die body. . Next, advance the external heating means as a heat source into the space,
The molding surface is heated via the rear surface by being arranged opposite to the rear surface of the insert. After that, as the mold is clamped, the external heating means is retracted from the space, the cooling means is brought into contact with the back surface of the insert, and the molding surface is cooled through the back surface.

[0015]

Embodiments of the present invention will be described below.

FIG. 1 is an explanatory view showing the cooling of the mold by the mold heating / cooling device according to the first embodiment of the present invention. FIG. 2 is an explanatory view showing the time of heating the mold by the mold heating / cooling device according to the first embodiment of the present invention. FIG. 3 is a sectional view showing a heating state by the heating means of the mold heating / cooling apparatus according to the first embodiment of the present invention. FIG. 4 is an enlarged sectional view of an essential part showing the heating means of the mold heating / cooling apparatus according to the first embodiment of the present invention. FIG. 5 is a cross-sectional view showing a cooling state by the cooling means of the mold heating / cooling apparatus according to the first embodiment of the present invention.

Since the heating / cooling device of this embodiment is embodied in an injection molding die, first, an outline of the structure of the injection molding die will be described.

In FIGS. 1 and 2, the injection molding die of this embodiment has a movable die plate 11 and a movable mounting plate 1.
The movable main mold 14 is attached via the spacer 2 and the spacer block 13. On the right side surface of the movable main mold 14, there is formed a core surface 14a having a convex cross section protruding rightward.
A part of the molding space S (inner side surface portion) is constituted by a. In addition, an extrusion pin 16 is fixed to the space inside the spacer block 13 via an extrusion plate 15 so as to protrude rightward. At the mold clamping position shown in FIG. 1, the extruding pin 16 has its tip end surface flush with the core surface 14a of the movable main mold 14. Further, at the mold opening position shown in FIG. 2, the pushing plate 17 is moved to the right by the drive shaft 17 of the driving mechanism, and the pushing pin 1 is moved.
The tip end surface of 6 projects rightward from the core surface 14a of the movable main mold 14 to facilitate removal of the molded product after cooling and solidification. On the other hand, a fixed back plate 23 is fixed to the fixed side die plate 21 via a fixed side mounting plate 22. An introduction recess 23a for introducing the injection nozzle 24 is formed in the center of the right side surface of the fixed back plate 23, and the fixed side mounting plate 2
Introducing holes 22a, 21a communicating with the introducing recess 23a are formed in the central portions of the stationary die plate 21 and the stationary die plate 21, respectively. In addition, the introduction recess 2 of the fixed back plate 23
A sprue 23b and a runner 23c are formed in the center of 3a, and both the introduction holes 21a and 22a and the introduction recess 2 are formed.
3a through the sprue 23b to the tip of the injection nozzle 24.
It is designed to be attached to. Since the above-mentioned structure is the same as that of a general injection mold, detailed description of the related parts will be omitted.

The fixed back plate 23 has a cooling section 23d having a convex cross-section protruding leftward at the center of the left side surface. On the right side of the cooling portion 23d of the fixed back plate 23, a plurality of cooling holes 23e are extended in the front-back direction (direction orthogonal to the paper surface in FIGS. 1 and 2), and a cooling fluid such as cooling water is supplied to the cooling holes 23e. By circulating, the temperature of the cooling unit 23d is lowered. A fixed main mold 24 is attached to the left side surface of the fixed back plate 23 so as to be movable left and right, and by a fixed main mold moving mechanism (not shown), the mold clamping position shown in FIG.
It reciprocates between the mold opening position shown in FIG. A cavity insert 26 is fitted and fixed to the central portion of the fixed main mold 24 via a heat insulating plate 25.

As shown in FIG. 3, the cavity insert 26
Has a cavity surface 26a forming another portion (outer surface portion) of the molding space S and a back surface 26b located on the opposite side of the cavity surface 26a. The cavity nest 2
The left side surface 26d of 6 and the left side surface 24a of the fixed main mold 24 and the left side surface 25a of the heat insulating plate 25 are flush with each other to form a parting surface or a parting line PL. Further, the right side surface 24b of the fixed main mold 24 and the right side surface 25b of the heat insulating plate 25 are flush with each other, and the cooling hole 23d of the fixed back plate 23 is closely fitted in the center of the heat insulating plate 25. 25c is provided to form a stepped recess between the right side surface 25b of the heat insulating plate 25 and the back surface 26b of the cavity insert 26. Then, as shown in FIG. 5, in the mold clamped state, the cooling part 23d is tightly fitted in the accommodation hole 25c, the cooling part 23d is in close contact with the back surface 26b of the cavity insert 26, and the right side of the fixed main mold 24. Surface 24b is fixed back plate 23
The left side surface 23f is closely contacted. Further, in the mold clamped state, the left side surfaces 24a, 25a, 26d of the fixed main mold 24, the heat insulating plate 25 and the cavity insert 26 are flush with the right side surface of the movable main mold 14, and the cavity insert 26
A molding space S having a substantially U-shaped cross section is formed between the cavity surface 26a of the above and the core surface 14a of the movable main mold 14. A gate 26c, which is aligned with and communicates with the runner 23c of the fixed back plate 23, is formed at the center of the cavity insert 26.

The fixed main mold 24, the heat insulating plate 25, and the fixed main mold moving mechanism (not shown) constitute a cavity insert moving means for reciprocating the cavity insert 26 in the left-right direction. Back 26b of child 26
Is contacted with the left side surface 23f of the fixed back plate 23 as the mold body, and when the mold is opened, the back surface 2 of the cavity insert 26 is
6b is detached from the left side surface 23f of the fixed back plate 23 to form a space with a predetermined distance between the back surface 26b and the fixed back plate 23. In addition, by the cooling portion 23d and the cooling hole 23e provided on the fixed back plate 23 as the mold body, it abuts on the back surface 26b of the cavity inserter 26 during mold clamping, and the cavity surface 26 via the back surface 26b.
The cooling means which cools a is comprised. The fixed main mold 24 is supported by the fixed back plate 23 via the guide pins 27 as well as the general injection mold, and the fixed main mold 24 is
The movable main mold 14 is guided to the left and right through the guide pins 27 so that the movable main mold 14 is aligned with the accurate mold clamping position.

Next, the external heating means of this embodiment will be described.

As shown in FIG. 3, the present embodiment is provided with first and second external heating means 31 and 32 having a substantially rectangular block shape corresponding to the cavity surface 26a as external heating means. The first external heating means 31 is retracted by the first moving mechanism 41 to the retracted position (the position shown in FIG. 1) that does not interfere with the cavity insert 26 during mold clamping, and the cavity insert 26 during mold opening. The cavity surface 26a is heated via the back surface 26b by advancing to a heating position (position in FIG. 2) that is in close contact with the back surface 26b. The width and height of the first external heating means 31 (front-back dimension and vertical dimension in the figure) are set to be smaller than the width and height of the accommodation hole 25c of the heat insulating plate 25 by a predetermined value, respectively. The front and rear and upper and lower side surfaces of the heating means 31 abut on the heat insulating plate 25 to prevent the heat insulating plate 25 from being directly heated. The size of the first external heating means 31 is set so that at least the substantially entire back surface 26b portion corresponding to the cavity surface 26a can be heated, and the size of the accommodation hole 25c of the heat insulating plate 25 is also set correspondingly.

Here, the cavity insert 26 has a wall thickness of at least a portion corresponding to the cavity surface 26a of 15 in order to improve heat conduction from the back surface 26b side.
It is preferable that the distance be set to mm or less. In particular, it is more preferable to set the wall thickness of the cavity insert 26 at the portion in contact with the first external heating means 31 to such a range. If the wall thickness is set to a value exceeding 15 mm, the heat conduction efficiency may decrease, and the heat transfer time from the back surface 26b side of the cavity insert 26 to the cavity surface 26a side may become long. On the other hand, the wall thickness is preferably 0.5 mm or more when the cavity insert 26 is processed by cutting. If the wall thickness is less than 0.5 mm, the cavity insert 26 may be difficult to cut or the workability may be reduced. If the cavity insert 26 can be made thinner by a processing method other than cutting, the lower limit thereof may be set to, for example, about 0.2 mm. However, if the lower limit value is less than 0.2 mm, the cavity insert 26 may be thermally deformed during heating or may be damaged by the injection pressure of the resin.

The second external heating means 32 is moved by the second moving mechanism 42 when the mold is clamped.
The retreat position (the position shown in FIG. 1) that does not interfere with the heating position, and the heating position (the position shown in FIG. 2) which faces the cavity surface 26a of the cavity inserter 26 with predetermined gaps d1, d2 and d3 when the mold is opened. The cavity surface 26a is heated by radiating heat to the cavity surface 26a. The width and height of the second external heating means 32 (front-back dimension and vertical dimension in the figure) are set to be smaller than the width and height of the cavity surface 26a of the cavity insert 26 by a predetermined value, respectively. The front and rear and upper and lower side surfaces of the heating means 32 abut on the cavity insert 26 to prevent the cavity insert 26 from being directly heated. Gaps d1, d2, d3 between the second external heating means 32 and the cavity surface 26a.
Is preferably as small as possible in order to increase the heat radiation efficiency, and is preferably about 0.2 mm. If the gap is less than 0.2 mm, it may be difficult to secure a constant gap between the second external heating means 32 and the cavity surface 26a, and the second external heating means 32 may be difficult.
May contact the cavity surface 26a and cause scratches.

Next, the first and second external heating means 31,
The details of the configuration of 32 will be described. Since the first external heating means also has the same configuration as the second external heating means, the corresponding parts are designated by the corresponding reference numerals and the duplicated description will be omitted.

First and second external heating means 31, 32
Is, as shown in FIG. 4, flat support plates 31a, 32a.
It also has a rectangular block shape with a three-layer structure in which flat plate-shaped heat plates 31c and 32c are also mounted on the plate-shaped heat sources 31b and 32b. The support plates 31a and 32a are the first
Or, it is located on the side of the second moving mechanism 41, 42,
Alternatively, it is preferably formed of a heat insulating material in order to prevent the influence of heat transfer to the second moving mechanisms 41 and 42. In addition, the heat sources 31b and 32b are the heat plates 31c and 3b.
It suffices that 2c can be heated to a desired temperature corresponding to the melting temperature of the injection resin, for example, around 350 ° C. within a fixed time, and a known electric heater is built in a metal having good thermal conductivity, or A heating fluid such as hot oil may be circulated. Further, the heating plates 31c and 32c are copper plates, etc.
It is made of a metal having a good thermal conductivity. In this embodiment,
As the heat plate 32c of the second external heating means 32, an electric discharge machining electrode in which the cavity surface 26a of the cavity insert 26 is machined is used, and the gaps d1, d2, d3 between the heat plate 32c and the cavity surface 26a are easily formed. I try to maintain a constant value. Incidentally, the first and second moving mechanisms 41, 42
As the above, various known two-dimensional to three-dimensional moving mechanisms such as a two-dimensional to three-dimensional combination of hydraulic cylinders can be adopted.

Next, the injection molding operation using the mold heating / cooling method by the mold heating / cooling apparatus of the present embodiment configured as described above will be explained. The injection molding operation is performed in accordance with a control program stored in advance in the ROM by using a control unit including a CPU, a ROM, a RAM and the like. FIG. 6 is a process diagram showing a method for heating and cooling a mold according to the first embodiment of the present invention.

First, in a mold opening process as a space forming process, a mold clamping device (not shown) of an injection molding machine is driven to
The movable main mold 14 is moved to the left through the movable die plate 11, the movable mounting plate 12, and the spacer block 13,
As the mold opening position in FIG. 2, the fixed main mold 24 and the fixed back plate 2 are provided.
A sufficient space is provided between the two and 3. Along with this, the fixed main mold 24 is moved to the left by the fixed main mold moving mechanism, the back surface 26b of the cavity insert 26 is separated from the fixed back plate 23, and between the movable main mold 14 and the fixed back plate 23. It is placed in the approximate middle position. As a result, as shown in FIG.
3 and the back surface 26b of the cavity insert 26, and between the cavity surface 26a of the cavity insert 26 and the movable main mold 14.
A space with a predetermined interval is formed between the space and the space.

Next, in the hot plate approaching step, the first moving mechanism 41 is driven to move the first external heating means 31 having the heat source 31b into the space between the fixed back plate 23 and the fixed main mold 24. To the rear surface 2 of the cavity insert 26.
It is arranged so as to face 6b. At the same time, the second moving mechanism 4
2 is driven to advance the second external heating means 32 having the heat source 32b into the space between the fixed main mold 24 and the movable main mold 14, and the hot plate 32c is moved to the cavity surface 2 of the cavity insert 26.
It is arranged so as to face 6a.

Then, as shown in FIGS. 2 and 3, in the heating step, the heating plate 31c of the first external heating means 31 is moved to the rear surface of the cavity insert 26 by the first and second moving mechanisms 41 and 42. While closely contacting 26b, the heat plate 32c of the second external heating means 32 is disposed close to the cavity surface 26a with predetermined gaps d1, d2, d3. Then, the heat plate 31c of the first external heating means 31 heats the back surface 26b of the cavity insert 26 by heat conduction, and indirectly heats the cavity surface 26a as the molding surface from the back surface 26b side. At the same time, the hot plate 32 c of the second external heating means 32 is connected to the cavity surface 26 a of the cavity insert 26.
Is heated directly by heat radiation. The heating time in this heating step is the thickness of the portion corresponding to the cavity surface 26a of the cavity insert 26 to be heated, the target heating value of the cavity surface 26a according to the type of injection resin, the heating plates 31c, 3
The temperature is appropriately changed depending on the heating temperature of 2c and the like. For example, A
BS resin is injected, and the thickness of the portion of the cavity insert 26 corresponding to the cavity surface 26a is set to 10 mm.
When the target temperature of a is 130 ° C., the heating plate 31
When the heating temperature of c and 32c is about 350 ° C., the heating time is about 30 to 40 seconds. Further, if the thickness of the portion corresponding to the cavity surface 26a of the cavity insert 26 is changed to 5 mm under such conditions, the cavity surface 26a can be brought to a temperature equivalent to the above temperature in a heating time of 20 seconds or less,
Further, in this case, if the heating time is 1 minute, the temperature of the cavity surface 26a can be set to about 200 ° C. At this time, the heat insulating plate 25 prevents the cavity insert 26 from releasing heat. Further, since the hot plate 32c of the second external heating means 32 is constituted by the electric discharge machining electrode, the gap between the cavity surface 26a and the cavity surface 26a can be made extremely small and uniform, that is, 0.2 mm, and the heat radiation can be reduced. This can be performed efficiently, and scratches due to contact can be prevented. Further, since the cavity insert 26 is made as thin as possible, heat can be efficiently conducted from the back surface 26b side. It should be noted that the temperature of the cavity surface 26a itself is determined according to the type of resin, the heating deformation temperature, etc., as in the ordinary mold temperature adjusting technique.

Then, in the hot plate separating step, the hot plate 31 of the first external heating means 31 is moved by the first moving mechanism 41.
c is separated from the position where it abuts the back surface 26b of the cavity insert 26, and is retracted from the space between the cavity insert 26 and the fixed back plate 24 to the retracted position of FIG. At the same time, the heating plate 32 of the second external heating means 32 is moved by the second moving mechanism 42.
c is separated from the position approaching the cavity surface 26a of the cavity insert 26, and is retracted from the space between the cavity insert 26 and the movable main mold 14 to the retracted position of FIG.

Thereafter, in the mold clamping step, the fixed main mold moving mechanism is driven to clamp the fixed main mold 24 to the fixed back plate 23, and the mold clamping device is driven to move the movable side die plate 11, Movable side mounting plate 12 and spacer block 13
The movable main mold 14 through the fixed main mold 24 and the fixed back plate 2
Tighten the mold for 3. Then, the movable main mold 14 and the cavity insert 26 are clamped at the parting surface, a molding space S having the same shape as the molded product is formed between the core surface 14a and the cavity surface 26a, and the fixed back plate. The sprue 23b and the runner 23c of 23 are the cavity insert 2
6 to the gate 26c. At the same time, the cooling portion 23d of the fixed back plate 23 comes into close contact with the back surface 26b of the cavity insert 26. In this state, sprue 23 the tip of the injection nozzle 24
By being pressed against b, the molten resin can be injected from the injection nozzle 24 into the molding space S through the sprue 23b, the runner 23c and the gate 26c.

In the injection process of the injection cooling process, the sprue 2 is ejected from the injection device (not shown) through the injection nozzle 24.
The molten resin is injected and injected into 3b, and the molten resin is filled into the molding space S formed between the cavity surface 26a and the core surface 14a from the gate 26c via the runner 23c. At this time, since the cavity surface 26a is heated to a desired temperature, the molten resin in contact with the cavity surface 26a reliably maintains the heat distortion temperature (for example, 160 ° C. to 170 ° C. in the case of ABS resin), and the flow mark, It is possible to reliably prevent the generation of silver streaks (silver streak).
Further, at the time of injection, since the cooling portion 23d of the fixed back plate 23 is in close contact with the back surface 26b of the cavity insert 26, a large amount of cooling water or other cooling fluid is supplied and distributed in the cooling holes 23e of the fixed back plate 23. By doing so, the back surface 26b of the cavity insert 26 can be instantaneously cooled by the cooling portion 23d as the cooling means, and the cavity surface 26a can be rapidly cooled by heat conduction, and the cooling and solidification of the molten resin is sufficiently promoted. be able to. At this time, since the cavity insert 26 is made as thin as possible, the cooling efficiency can be improved. As a result, the temperature of the injection resin becomes equal to or lower than the heating deformation temperature, the material is rapidly cooled and solidified, and a molded product having a predetermined shape corresponding to the molding space S is quickly molded. The temperature gradient of the cavity surface 26a from the injection of the molten resin to the cooling and solidification can be appropriately adjusted by the initial heating temperature of the cavity surface 26a and the cooling temperature of the cooling unit 23d.

Thereafter, in the mold opening step shown in FIG. 3, the mold clamping device is driven to separate the movable main mold 14 from the fixed main mold 24 and open the mold. As a result, the core surface 14a and the cavity surface 26a are opened, and the molded product becomes the cavity surface 2
It is released from 6a and remains on the core surface 14a. After that, in the product taking-out step, the extrusion driving means (not shown) is driven to cause the extrusion pin 16 to project from the core surface 14a so that the molded product is made into the core surface 1
The product is taken out by extruding from 4a and separating.

After that, the series of steps described above is repeated, and a resin molded product having a desired shape can be continuously obtained.

As described above, in the mold heating / cooling apparatus of the above-described embodiment, the cavity surface 2 forming a part of the molding space S is formed.
6a and a cavity backing 26 having a back surface 26b located on the side opposite to the cavity surface 26a. When the mold is clamped, the back surface 26b of the cavity backing 26 is brought into contact with the fixed back plate 23 as the mold body. , A fixed main mold as a cavity nest moving means 24 for separating the back surface 26b of the cavity insert 26 from the fixed back plate 23 to form a predetermined space between the back surface 26b and the fixed back plate 23 when the mold is opened. 24, the heat insulating plate 25, the fixed main mold moving mechanism, and the first moving mechanism 41, the cavity insert 2 at the time of mold clamping.
6 retreat to a position where it does not interfere with 6 and advances to a position where it abuts the back surface 26b of the cavity insert 26 when the mold is opened, and the back surface 26b is transferred by heat conduction from the hot plate 31c.
By the first external heating means 31 for heating the cavity surface 26a via the second moving mechanism 42 and the second moving mechanism 42, the cavity is retracted to a position where it does not interfere with the cavity insert 26 during mold clamping, and the cavity is opened during mold opening. A second external heating means 32 having a hot plate 32c for advancing to a position close to and facing the cavity surface 26a of the insert 26 and heating the cavity surface 26 by heat radiation from the hot plate 32c. Is provided on the fixed back plate 23 and abuts on the back surface 26b of the cavity insert 26 when the mold is clamped.
A cooling unit 23d and a cooling hole 23e as cooling means for cooling the cavity surface 26a via b are provided.

Therefore, in the above embodiment, the cooling portion 23d is separated from the cavity insert 26 and does not cool the cavity insert 26 when the die is heated, so that the first and second external heating means 31 are provided. , 32 can heat the cavity insert 26 efficiently and quickly. Further, when the mold is cooled, the first and second external heating means 31, 32 are not retracted from the cavity insert 26 and the cavity insert 26 is not heated.
Cooling of the cavity insert 26 by 3d can be performed efficiently and quickly, and the cooling and solidification rate of the resin can be increased. As a result, the heating performance and the cooling performance can be improved respectively, and the molding cycle from the resin injection after heating the mold to the solidification and removal of the resin accompanying the cooling of the mold can be greatly shortened. Further, the first and second external heating means 31, 32 and the cooling unit 23d are
Since they operate independently in a thermally separated form, the optimum thermal gradient of the temperature of the cavity surface 26a can be easily and quickly obtained according to the type of the injection resin, and the product quality can be improved. That is, in the case of heating by a heater built in a mold or a heating source such as hot water or hot oil as in the conventional case, it is difficult to lower the temperature of the heating source itself and it cannot be said that the thermal response at the time of cooling is sufficient. In the present embodiment, since the first and second external heating means 31 and 32 as the heating source are retracted to the position spatially separated from the mold, the thermal response in the case where the mold to be heated is entangled or otherwise. The sex can be increased. By increasing the mold temperature at the start of the resin material emphasis, the appearance of the molded product is improved, and the mold temperature is lowered by the heat removal effect of the cooling unit 23d which starts immediately after the mold is clamped. It is possible to shorten the molding cycle required until the product is taken out. In other words, the apparatus of the present embodiment enables a large change in the mold temperature, so that a high-quality molded product can be produced in a high molding cycle.

The heating means is not a mold built-in type, but the first and second external heating means 31, 32.
While a type arranged outside the mold is used, as the heat sources 31b and 32b themselves, a well-known heat source having a relatively simple structure such as an electric heater can be used, and therefore high frequency induction heating or SSI molding is possible. As compared with the case of using such an expensive or complicated configuration as described above, the facility cost can be significantly reduced, the maintenance thereof can be easily performed, and the maintainability can be improved. Furthermore, since the second external heating means 32 does not directly contact the cavity surface 26a that determines the surface quality of the molded product, it is possible to prevent the scratches and quality deterioration such as metal burning due to thermal oxidation.
Good quality of the product itself can be maintained.

The thickness of the cavity insert 26 is about 0.5 mm to 15 at least at the portion corresponding to the cavity surface 26a.
By setting the thickness in the range of mm, the heating of the cavity surface 26a from the back surface 26b side of the cavity insert 26 can be performed more efficiently and quickly, and the temperature rise of the cavity surface 26a can be further increased. Then, by reducing the gaps d1, d2, d3 between the heat plate 32c of the second external heating means 32 and the cavity surface 26a to about 0.2 mm, the heating efficiency by the heat radiation from the second external heating means 32 is increased. Can be increased. As a result, the cavity surface 26
It is possible to further shorten the heating time of a and further shorten the entire molding cycle. Furthermore, since the hot plate 31c of the first external heating means 31 is in close contact with the back surface 26b of the cavity insert 26 that does not affect the quality of the molded product, the quality of the molded product is maintained well, while the cavity surface is kept. The heating of 26a can be performed more efficiently.

Since the cavity insert 26 is attached to the fixed main mold 24 via the heat insulating plate 25, the heat insulating plate 25 can prevent the heat stored in the cavity insert 26 from being dissipated. Furthermore, the first and second external heating means 31, 32
By configuring the support plates 31a and 32a of the above with a heat insulating material, it is possible to effectively prevent the heat dissipation from the first and second external heating means 31 and 32, and at the same time, to move the first and second moving mechanisms. It is possible to prevent the influence of heat conduction on 41 and 42.

Next, a second embodiment according to the present invention will be described below. In the present embodiment, only the differences from the first embodiment will be described, and the same components as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted.

FIG. 7 is a sectional view showing a heating state by the heating means of the mold heating / cooling apparatus according to the second embodiment of the present invention.

In this embodiment, the shape of the hot plate corresponding portion of the second external heating means 51 is different from that of the first embodiment, and other configurations are the same as those of the first embodiment.
That is, at least the portion corresponding to the hot plate of the second external heating means 51 has the first heating surface 51a that closely faces and faces the cavity surface 26a of the cavity insert 26 at the time of mold opening, and the first heating surface 51a. Second heating which extends on the heating surface 51a and contacts the parting surface consisting of the left side surface 26d of the cavity insert 26 when the mold is opened to heat the cavity surface 26a through the parting surface by heat conduction. It has a surface 51b. Similar to the heat plate 32c of the second external heating means 32 of the first embodiment, the first heating surface 51a has a predetermined small gap between it and the cavity surface 26a, and the cavity surface 26a is exposed by heat radiation. To heat.

In addition to the same operation and effect as in the first embodiment, the present embodiment further efficiently heats the cavity surface 26a from the cavity surface 26a side by the second external heating means 51 in a short time. There is an effect that it can be performed.

By the way, each of the above-described embodiments has been described by embodying the mold heating and cooling apparatus and the method thereof, but in the case of practicing the present invention, at least the cavity nest moving means and the first or second means. External heating means 31, 32, 51
It may be embodied in a mold heating device consisting of. Further, as the mold, other than the injection mold, the mold may be embodied as a mold in which preheating of the cavity surface is considered effective.

Further, as in each of the above-mentioned embodiments, the first or second external heating means 31, 32 are connected to the support plates 31a, 32.
Instead of the three-layer structure of a, the heat sources 31b and 32b, and the heat plates 31c and 32c, a single-layer structure including a heat source may be used, and other configurations may be adopted. In this case, in the second external heating means 51 of the second embodiment, at least the hot plate portion is composed of the first and second heating surfaces 51a and 51b.

In each of the above-mentioned embodiments, the predetermined gaps d1, d2, d3 are provided between the second external heating means 32, 51 and the cavity surface 26a, but the heat plate 32c is made of a copper plate or the like.
If the cavity insert 26 is made of a material having a hardness lower than that of the cavity insert 26, the second external heating means 32, 51 are provided on the cavity face 26
It is also possible to make contact with a and heat directly by heat conduction. However, in the case of a mold of the type in which the cavity surface 26a is provided with a texture pattern, the second external heating means 32, 5 is also used.
It is necessary to provide a predetermined gap between the cavity 1 and the cavity surface 26a.

Further, in this apparatus and method, at least one of the core surface 14a and the cavity surface 26a forming the molding space S is thermally separated from the cooling means before being injected by the external heating means. It may be preheated, and for example, the core surface may be provided in the core insert and at least one of the core surface and the back surface of the core insert may be heated by the external heating means instead of the cavity face. In this case, the shape of the hot plate of the external heating means is made to correspond to the core surface shape and the back surface shape of the core insert. In contrast to the above embodiments, the core surface may be provided on the fixed main mold side instead of the movable main mold side, and the cavity surface may be provided on the movable main mold side. Further, the cooling means is not limited to that of the above embodiment, and other cooling means can be adopted.

In the present specification, "mold body"
Is adjacent to the cavity insert 26 or the core insert,
Refers to the mold part that contacts these, in the above embodiment,
The fixed back plate 23. When the core surface is provided on the core insert and the core insert is heated, the movable back plate adjacent to the core insert becomes the mold body.

[0051]

As described above, in the mold heating apparatus according to the first aspect of the invention, the back surface of the insert is externally separated from the mold body in a spatially separated state and substantially thermally insulated. Since the molding surface of the insert can be heated by the heating means, the heating efficiency is improved. As a result, the mold temperature can be changed significantly, and high-quality molded products can be produced in a short molding cycle.

According to a second aspect of the present invention, there is provided an apparatus for heating a die, wherein the back surface of the insert is spatially separated from the die body provided with the cooling means and is substantially thermally insulated. As a result, the molding surface of the insert can be heated, so that the heating efficiency is improved. Further, since the molding surface is heated from the back surface side, it is possible to prevent the molding surface from being scratched and the possibility of metal burning due to thermal oxidation. Further, when the insert is cooled, the molding surface of the insert can be cooled in a state where the external heating means is spatially separated from the mold body and is substantially thermally insulated, so that the cooling efficiency is improved. . As a result, the mold temperature can be changed significantly, and high-quality molded products can be produced in a short molding cycle.

In the mold heating / cooling device according to the third aspect of the present invention, the back surface of the cavity insert is spatially separated from the mold body provided with the cooling means, and is substantially thermally insulated.
Since the molding surface of the cavity insert can be heated by the external heating means, the heating efficiency is improved. Further, since the molding surface is heated from the back surface side, it is possible to prevent the molding surface from being scratched and the possibility of metal burning due to thermal oxidation. Further, when the cavity insert is cooled, the molding surface of the cavity insert can be cooled while the external heating means is spatially separated from the mold body and is substantially thermally insulated, so that the cooling efficiency is improved. improves. As a result, the mold temperature can be changed significantly, and high-quality molded products can be produced in a short molding cycle.

According to a fourth aspect of the present invention, there is provided a mold heating / cooling device in which the back surface of the cavity insert is spatially separated from the mold body provided with the cooling means and is substantially thermally insulated.
Since the molding surface of the cavity insert can be heated by the first and second external heating means, the heating efficiency is improved. Further, since the first external heating means directly contacts the back surface of the cavity inserter to indirectly heat the molding surface by heat conduction, it is possible to prevent the molding surface from being scratched, the metal burning due to thermal oxidation, and the like. Moreover, the heating efficiency can be further improved. On the other hand, since the second external heating means directly heats the cavity surface by heat radiation, it is possible to prevent damage to the molding surface, metal burning due to thermal oxidation, and the like, and further improve heating efficiency. Further, when the cavity insert is cooled, the molding surface of the cavity insert can be cooled while the first and second external heating means are spatially separated from the mold body and are substantially thermally insulated. Therefore, the cooling efficiency is improved. As a result, the mold temperature can be changed significantly, and high-quality molded products can be produced in a short molding cycle.

In addition to the invention of claim 4, the mold heating / cooling device according to the invention of claim 5 does not require special processing which is usually performed to adapt the second external heating means to the shape of the cavity surface. The cost of parts can be reduced, and the predetermined gap between the second external heating means and the cavity surface can be provided easily and accurately.

In the mold heating / cooling device according to the invention of claim 6, in addition to the invention of claim 4, the second heating surface of the second external heating means directly contacts the parting surface of the cavity insert. In contact with each other, the cavity surface located in the immediate vicinity is efficiently heated by heat conduction. In addition, the first heating surface efficiently heats the cavity surface by heat radiation. As a result, the molding cycle can be further shortened.

According to a seventh aspect of the present invention, in addition to the invention according to any one of the first to fourth aspects, the mold heating / cooling device has a cavity insert having a sufficiently small wall thickness, so that the first external The heat conduction heating from the back side of the cavity insert by the heating means can be performed more efficiently.

According to the eighth aspect of the present invention, there is provided a method of heating a mold by the external heating means in a state where the back surface of the mold is spatially separated from the mold body and is substantially thermally insulated. Since the molding surface can be heated, the heating efficiency is improved. As a result, the mold temperature can be changed significantly,
High quality molded products can be produced in a short molding cycle.

According to a ninth aspect of the present invention, there is provided a method for heating and cooling a die, wherein the back surface of the insert is spatially separated from the die body provided with the cooling means and is externally heated while being substantially thermally insulated. Since the molding surface of the insert can be heated by the means,
The heating efficiency is improved. Further, since the molding surface is heated from the back surface side, it is possible to prevent the molding surface from being scratched and the possibility of metal burning due to thermal oxidation. Further, when cooling the insert, the molding surface of the insert can be cooled in a state where the external heating means is spatially separated from the mold body and is substantially thermally insulated, so that the cooling efficiency is improved. To do. As a result, the mold temperature can be changed significantly, and high-quality molded products can be produced in a short molding cycle.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a mold being cooled by a mold heating / cooling device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a mold heating time by the mold heating / cooling device according to the first embodiment of the present invention.

FIG. 3 is a sectional view showing a heating state by the heating means of the mold heating / cooling apparatus according to the first embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of essential parts showing a heating means of the mold heating / cooling apparatus according to the first embodiment of the present invention.

FIG. 5 is a sectional view showing a cooling state by the cooling means of the mold heating / cooling apparatus according to the first embodiment of the present invention.

FIG. 6 is a process diagram showing a method for heating and cooling a mold according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a heating state by the heating means of the mold heating / cooling apparatus according to the second embodiment of the present invention.

[Explanation of symbols]

14a Core surface (molding surface) 23 Fixed back plate (die body) 23d Cooling part (cooling means) 23e Cooling hole (cooling means) 24 Fixed main mold (nesting moving means, cavity inserting moving means) 25 Insulating plate ( Nest moving means, cavity nest moving means) 26 Cavity nest (nesting) 26a Cavity surface (molding surface) 31 First external heating means (external heating means) 32 Second external heating means (external heating means) 51 Second External Heating Means (External Heating Means) 51a First Heating Surface 51b Second Heating Surface S Forming Space

Claims (9)

[Claims] 1. A mold which is connected to a nest having a molding surface forming a molding space and a back surface located on the opposite side of the molding surface, and the mold back is brought into contact with the mold body when the mold is clamped. When moving, the back side of the insert is separated from the mold body to form a predetermined space between the back side and the mold body, and retracted to a position where it does not interfere with the insert when the mold is clamped. In addition, when the mold is opened, it advances to a position facing either the molding surface or the back surface of the insert and directly heats the molding surface by heat transfer, or indirectly heats through the back surface. And a heating device for a mold. 2. A mold is connected to a nest having a molding surface forming a molding space and a back surface located on the opposite side of the molding surface, and the back surface of the nest is brought into contact with a mold body during mold clamping, When moving, the back side of the insert is separated from the mold body to form a predetermined space between the back side and the mold body, and retracted to a position where it does not interfere with the insert when the mold is clamped. In addition, when the mold is opened, the external heating means that advances to a position facing the back surface of the insert and heats the molding surface through the back surface by heat transfer, is provided in the mold body, A heating / cooling device for a die, comprising: a cooling unit that is in contact with the back surface of the writing tool and cools the molding surface via the back surface. 3. A cavity insert having a cavity surface forming a part of a molding space and a back surface located on the opposite side of the cavity surface, the back surface of the cavity insert being connected to a mold body during mold clamping. Cavity insert moving means that abuts and separates the back surface of the cavity insert from the mold body when the mold is opened to form a predetermined space between the back surface and the mold body; An external heating means for retreating to a position where it does not interfere with the insert and advancing to a position where it comes into contact with the back surface of the cavity insert when the mold is opened, and heating the cavity surface via the back surface by heat conduction; Heating and cooling of a mold, comprising: a cooling unit, which is provided in the main body, contacts the back surface of the cavity inserter when the mold is clamped, and cools the cavity surface through the back surface. Location. 4. A cavity insert having a cavity surface forming a part of a molding space and a back surface located on the opposite side of the cavity surface is connected, and the back surface of the cavity insert is attached to a mold body during mold clamping. Cavity insert moving means that abuts and separates the back surface of the cavity insert from the mold body when the mold is opened to form a predetermined space between the back surface and the mold body; A first external heating means that retreats to a position where it does not interfere with the insert, advances to a position where it abuts the back surface of the cavity insert when the mold is opened, and heats the cavity surface through the back surface by heat conduction, When the mold is clamped, it retreats to a position where it does not interfere with the cavity inserter, and when the mold is opened, it advances to a position close to and facing the cavity surface of the cavity inserter to a position facing and opposing heat radiation. Second external heating means for heating the cavity surface by means of: cooling means provided on the mold body for contacting the back surface of the cavity insert during mold clamping and cooling the cavity surface via the back surface. A heating / cooling device for a mold, comprising: 5. The mold heating / cooling device according to claim 4, wherein the second external heating means is constituted by an electric discharge machining electrode having a cavity surface of the cavity insert machined. 6. The second external heating means is provided to extend to the first heating surface and a first heating surface that closely opposes the cavity surface of the cavity insert with a predetermined gap when the mold is opened. 5. The gold according to claim 4, further comprising a second heating surface that contacts the parting surface of the cavity inserter when the mold is opened and heats the cavity surface via the parting surface by heat conduction. Mold heating and cooling device. 7. The mold according to claim 1, wherein the thickness of at least a portion of the insert corresponding to the cavity surface is in the range of 0.5 mm to 15 mm. Heating and cooling device. 8. A method of heating a mold having a molding surface forming a molding space and a back surface located on the opposite side of the molding surface before injection molding, comprising: A space forming step of separating a back surface from the mold body to form a predetermined space between the back surface and the mold body, and advancing an external heating means having a heat source into the space to form a back surface of the nest. And a heating step of heating the molding surface via the back surface by facing each other by heat transfer. 9. A method of heating a mold having a molding surface forming a molding space and a back surface located on the opposite side of the molding surface before injection molding, the method comprising: A space forming step of separating a back surface from the mold body to form a predetermined space between the back surface and the mold body, and advancing an external heating means having a heat source into the space to form a back surface of the nest. A heating step in which the molding surface is heated via the back surface by being arranged facing each other, and with mold clamping, the external heating means is retracted from the space, and a cooling means is brought into contact with the back surface of the insert, And a cooling step of cooling the molding surface via the back surface.