JPH10138351A - Plastic molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve facial precision by making release of a molded product from a mold easy by a method wherein an elastic component wherein a shape is held in compression, and a forming part and a side plate part are alienated from each other in releasing of clamp are provided between a clamping mechanism of a separated mold and a cavity formed part, a side plate part, and an engaging part with a plastic basic material is provided to the side plate part. SOLUTION: Thermoplastic plastic base material 23 is inserted into a cavity formed with a top mold 21 and a bottom mold 23, and a cavity is formed with a cavity forming part 21a and a cavity side plate part 24b in the top mold. Further, in the bottom mold 22, the cavity is formed with a cavity forming part 22a and a cavity side plate part 22b. By compressing by fastening the forming part 22a and the side plate part 22b with a mold clamping mechanism 33, a regular cavity shape is held between the forming part 22a and the side plate part 22b. In releasing the clamp, a compression spring 34 forming a gap is interposed between both parts 22a, 22b. Further, a recessed difference in level as an engaging part with the plastic base material 23 is provided to both ends in contact with the side plate part 22b of the forming part 22a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic molding apparatus, and more particularly to a plastic molding apparatus for producing a highly accurate plastic molded article having a mirror surface such as a plastic lens or a mirror.

[0002]

2. Description of the Related Art Hitherto, as a method for producing a high-precision plastic molded product such as a lens or a mirror, for example, a method described in Japanese Patent Application Laid-Open No. 4-163119 is known. In this method, after previously processing a plastic base material into a substantially final shape by injection molding, the plastic base material is inserted into a pair of molds having at least one or more cavities having at least one or more mirror surfaces, The mold is heated and melted at a temperature equal to or higher than the glass transition temperature of the plastic base material to generate a resin internal pressure, and then gradually cooled to transfer the mirror surface in the cavity to the plastic base material.

Further, as an apparatus configuration for achieving such a manufacturing method, for example, there is one as described in Japanese Patent Application Laid-Open No. 5-220860, which is shown in FIG. In FIG. 12, a thermoplastic plastic base material 3 which has been previously formed into a cavity formed by an upper mold 1 and a lower mold 2 by injection molding so as to have substantially the same shape and volume as the cavity is inserted.

The upper mold 2 is arranged in a direction orthogonal to a mold clamping direction (up and down direction in FIG. 12) for bringing the upper mold 1 and the lower mold 2 into contact with each other, and has a cavity forming surface having a cavity forming surface in the mold clamping direction. Part 1a and this cavity forming part 1a
A cavity is defined by a cavity-side plate portion 1b having a cavity-forming surface surrounding the cavity-forming surface, and the cavity-forming portion 1a and the cavity-side plate portion 1b are integrally formed.

The lower mold 2 is divided into a plurality of cavity forming portions 2a and cavity side plate portions 2b around the cavities, and the cavity forming portions 2a and the cavity side plate portions 2b are aligned with a mold clamping direction (vertical direction in the figure). They are arranged in orthogonal fastening directions. Outside the upper mold 1 and the lower mold 2, the heaters 7a and 8a for holding the molds 1 and 2 and controlling the temperature of the molds 1 and 2 and the cooling sections 7b and 8b for cooling are provided. Mold temperature control units 7 and 8 having both are provided, and the outsides of the mold temperature control units 7 and 8 are supported by upper and lower die plates 11 and 12 via heat insulating plates 9 and 10, respectively.

A mold clamping mechanism 13 is provided on both sides of the mold 2 to clamp the cavity forming portion 2a and the cavity side plate portion 2b in a direction orthogonal to the mold clamping direction. , An air pressure or an electric motor is used. A compression spring 15 is interposed between the cavity forming portion 2a and the cavity side plate portion 2b. This compression spring 15 is used when the mold forming mechanism 13 tightens the cavity forming portion 2a and the cavity side plate portion 2b. To maintain the regular cavity shape together with the cavity forming portion 1a and the cavity side plate portion 1b, and when the clamping of the mold clamping mechanism 13 is released, the cavity forming portion 2a and the cavity side plate portion 2b
A gap is formed between them.

In such a plastic molding apparatus, the upper mold 1 and the lower mold 2 are opened up and down, a pre-processed thermoplastic plastic base material 3 is inserted into the cavity, and then a mold clamping mechanism is provided. The upper dies 1 and 2 are clamped from both sides with a predetermined pressure by using the 13, and then the die is clamped with a predetermined pressure from the die clamping direction using a press (not shown).
At this time, by compressing the compression spring 15, the shape of the regular cavity is maintained, and the occurrence of burrs during molding is suppressed.

Next, when the temperature of the base material 3 becomes equal to or lower than the thermal deformation temperature, the mold is opened and the tightening of the tightening mechanism 13 is released to generate the repulsive force of the compression spring 15 to form the cavity. A gap is formed between the portion 2a and the cavity side plate portion 2b, and the final molded product 3 is
It is easy to take out by peeling it off.

[0009]

However, in such a conventional plastic molding apparatus, when the tightening of the tightening mechanism 13 is released, a repulsive force of the compression spring 15 is generated and the cavity forming portion 2a is formed. And a gap is formed between the cavity side plate portion 2b, so that a slight difference between the left and right adhesion forces between the molded product 3 surface and the cavity side plate portion 2b surface side and a slight deviation in the right and left separation timing are caused. When this occurs, the molded product 3 slides on the cavity forming portion 2a as shown by an arrow in FIG. 13 even if the repulsive force of the compression spring 15 is increased, and the adhesion force is strong, or the cavity side plate portion 2b moves. The side surface of the molded product 3 remains in close contact with the surface of the cavity side plate portion 2b on the side where the timing is delayed, and there has been a problem that it is difficult to release the molded product 3 from the mold.

[0010] Further, even when the mold is released, the mold release resistance is increased, so that the molded article 3 is distorted and the accuracy thereof is deteriorated.
In order to avoid such problems,
It suffices to make the adhesion of both sides of the molded product 3 to the cavity side surface 2b exactly the same, and make the right and left separation timings exactly the same. Is desired.

Accordingly, the present invention provides a plastic molding apparatus which can easily release a molded product when the molded product is taken out, and can prevent deformation of the molded product and deterioration of surface accuracy at the time of release. It is intended to provide.

[0012]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, a pair of molds having at least one cavity having at least one mirror surface is provided, and the shape and the volume of the cavity are substantially the same as those of the cavity by injection molding in advance. After inserting and clamping the molded plastic base material, the plastic base material is heated and melted above its glass transition temperature to generate an internal resin pressure, and then gradually cooled to transfer the mirror surface to the plastic base material. In the plastic molding die as described above, at least one of the pair of dies is arranged separately in a direction orthogonal to a clamping direction in which the dies are brought into contact with each other, and has a cavity forming surface on the clamping direction side. A cavity side plate having a cavity and a cavity forming surface surrounding the cavity forming surface adjacent to the cavity forming portion; A separation mold in which a cavity is defined, a mold clamping mechanism for clamping the separation mold from both sides in a direction substantially orthogonal to the mold clamping direction, and a cavity forming portion and a cavity side plate portion of the separation mold. An elastic member that is interposed and is compressed to hold a regular cavity shape when tightened by the mold tightening mechanism, and separates the cavity forming portion and the cavity side plate portion by the repulsive force when the tightening is released. It is characterized in that engaging portions for engaging with the plastic base material are provided at both ends of the portion in contact with the cavity side plate portion.

[0013] In this case, when the fastening of the cavity forming portion and the cavity side plate portion by the mold clamping mechanism is released and the cavity forming portion and the cavity side plate portion are separated by the repulsive force of the elastic member, the molded product is removed from the cavity forming portion. To prevent the molded product from sliding on the cavity forming portion and coming into close contact with any one of the adjacent cavity side plate portions.

As a result, it is possible to easily release the molded product at the time of taking out the molded product, and it is possible to prevent the molded product from being deformed and the surface accuracy from deteriorating at the time of releasing the molded product. According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, the engaging portion extends in the same direction as the mold clamping direction and moves with the moving direction of the separation mold. It is characterized in that it comprises a gap extending over a predetermined length in a direction perpendicular to the direction.

In this case, the molded product is engaged with the gap of the cavity forming portion, and it is possible to prevent the molded product from sliding on the cavity forming portion and coming into close contact with one of the adjacent cavity side plates. According to a third aspect of the present invention, in order to solve the above problem, in the second aspect of the present invention, the height of the step is formed to be 0.3 mm or more.

In this case, the molded product is securely engaged with the gap of the cavity forming portion, and it is possible to reliably prevent the molded product from sliding on the cavity forming portion. According to a fourth aspect of the present invention, in order to solve the above-mentioned problem, in the second or third aspect of the present invention, the length of the step in the extending direction is formed to be at least half of the cavity forming surface of the cavity forming portion. It is characterized by that.

In this case, the molded product is securely engaged with the gap of the cavity forming portion, and it is possible to reliably prevent the molded product from sliding on the cavity forming portion. According to a fifth aspect of the present invention, in order to solve the above-mentioned problems, the surface roughness of the step is Ra = 0.
It is characterized in that it is 1 μm or less.

In this case, when the molded product is taken out, the molded product can be prevented from being firmly eroded by the difference, and the molded product can be easily released from the mold. In addition, it is possible to reliably prevent the surface accuracy from deteriorating. According to a sixth aspect of the present invention, in order to solve the above-mentioned problem, in the first aspect of the present invention, the engaging portion extends in the same direction as the mold clamping direction and moves in a direction in which the separation mold moves. It is characterized by comprising a C-chamfered portion extending over a predetermined length in a direction perpendicular to the direction.

In this case, the molded product is the C of the cavity forming portion.
The molded product is engaged with the chamfered portion to prevent the molded product from sliding on the cavity forming portion and coming into close contact with one of the adjacent cavity side plates. According to a seventh aspect of the present invention, in order to solve the above problem, in the sixth aspect of the present invention, the size of the C chamfered portion is formed to be 0.3 mm or more.

In this case, the molded product is C in the cavity forming portion.
The molded product is securely engaged with the chamfered portion, and the molded product can be reliably prevented from sliding on the cavity forming portion. According to an eighth aspect of the present invention, in order to solve the above problem, in the invention of the sixth or seventh aspect, the length of the C chamfered portion in the extending direction is equal to or more than の of the cavity forming surface of the cavity forming portion. It is characterized by being formed.

In this case, the molded product is the C of the cavity forming portion.
The molded product is securely engaged with the chamfered portion, and the molded product can be reliably prevented from sliding on the cavity forming portion. According to the ninth aspect of the present invention, in order to solve the above-mentioned problem, the sixth to eighth aspects of the present invention provide a method for manufacturing a semiconductor device.
The invention according to any one of the above aspects, characterized in that the surface roughness of the C chamfered portion is set to Ra = 0.1 μm or less.

In this case, it is possible to prevent the molded product from firmly coming into contact with the C-chamfered portion when the molded product is taken out, and to easily release the molded product from the molded product. Deformation and deterioration of surface accuracy can be reliably prevented. The invention according to claim 10 is
In order to solve the above problem, in the invention according to claim 1, the engaging portion extends in the same direction as the mold clamping direction and extends for a predetermined length in a direction orthogonal to a moving direction of the separation mold. And a curved surface portion extending.

In this case, the molded product is engaged with the curved surface portion of the cavity forming portion, and it is possible to prevent the molded product from sliding on the cavity forming portion and coming into close contact with one of the adjacent cavity side plates. According to an eleventh aspect of the present invention, in order to solve the above problem, in the invention according to the tenth aspect, the curved surface portion has a difference in height from the bottom surface of the cavity forming portion.
It is characterized by being formed to 0.3 mm or more.

In this case, the molded product is securely engaged with the curved surface of the cavity forming portion, and the molded product can be reliably prevented from sliding on the cavity forming portion. According to a twelfth aspect of the present invention, in order to solve the above-mentioned problem, a pair of dies having at least one or more cavities having at least one or more mirror surfaces are provided, and the cavities and the shapes are previously formed in the cavities by injection molding. And after inserting the plastic base material molded into approximately the same shape and closing the mold,
In a plastic molding die in which the plastic base material is heated and melted at a temperature equal to or higher than its glass transition temperature to generate a resin internal pressure, the mirror surface is gradually cooled to transfer the mirror surface to the plastic base material. At least one of which is separately arranged in a direction orthogonal to a mold clamping direction in which the molds are brought into contact with each other, and has a cavity forming portion having a cavity forming surface on the mold clamping direction side and the cavity forming portion adjacent to the cavity forming portion. A separation mold in which a cavity is defined by a cavity side plate having a cavity forming surface surrounding the surface, a mold clamping mechanism for clamping the separation mold from both sides in a direction substantially orthogonal to the mold clamping direction, and the separation mold. It is interposed between the cavity forming portion of the mold and the cavity side plate portion, and is compressed and tightened when tightened by the mold tightening mechanism. An elastic member that holds the cavity shape and separates the cavity forming portion and the cavity side plate portion by a repulsive force when the tightening is released, and an engaging portion that engages the plastic base material at both ends in the extending direction of the cavity forming portion. It is characterized by having a section.

In this case, when the fastening of the cavity forming portion and the cavity side plate portion by the mold clamping mechanism is released, and the cavity forming portion and the cavity side plate portion are separated from each other by the repulsive force of the elastic member, the molded product is removed from the cavity forming portion. To prevent the molded product from sliding on the cavity forming portion and coming into close contact with any one of the adjacent cavity side plate portions.

As a result, it is possible to easily release the molded product at the time of taking out the molded product, and to prevent the molded product from being deformed and the surface accuracy from deteriorating at the time of release. Further, since the engaging portions are formed at both ends in the extending direction of the cavity forming portion, it is possible to prevent the molded product from being deformed when molding a long or thin-shaped easily deformable molded product. it can.

According to a thirteenth aspect of the present invention, in order to solve the above-mentioned problem, in the twelfth aspect of the present invention, the engaging portion comprises a projection projecting from the cavity forming portion. In this case, the molded article is engaged with the projection of the cavity forming section, and it is possible to prevent the molded article from sliding on the cavity forming section and coming into close contact with one of the adjacent cavity side plates.

According to a fourteenth aspect of the present invention, in order to solve the above-mentioned problems, in the twelfth aspect of the present invention, the engaging portion comprises a gap having a height difference from a cavity forming surface. In this case, the molded product is engaged with the gap of the cavity forming portion, and it is possible to prevent the molded product from sliding on the cavity forming portion and coming into close contact with one of the adjacent cavity side plates.

According to a fifteenth aspect of the present invention, in order to solve the above-mentioned problem, in the twelfth aspect of the present invention, the engaging portion comprises a C chamfer. In that case,
The molded product is engaged with the C-chamfered portion of the cavity forming portion, and it is possible to prevent the molded product from sliding on the cavity forming portion and coming into close contact with one of the adjacent cavity side plates.

[0030]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 9 are views showing a first embodiment of a plastic molding apparatus according to the present invention.
11 corresponds to any one of the inventions. First, the configuration will be described. In FIGS. 1 and 2, reference numeral 21 denotes an upper die, and 22 denotes a lower die. The inside of the cavity formed by the upper die 21 and the lower die 22 is preliminarily processed by injection molding to have a shape and volume substantially equal to those of the cavity. The inserted thermoplastic base material 23 is inserted.

The upper mold 21 is arranged in a direction orthogonal to a mold clamping direction (up and down direction in FIG. 1) for bringing the upper mold 21 and the lower mold 22 into contact with each other, and has a cavity forming surface on the mold clamping direction side. Forming part 21a and this cavity forming part
A cavity is defined by a cavity side plate portion 21b having a cavity forming surface surrounding the cavity forming surface adjacent to 21a, and the cavity forming portion 21a and the cavity side plate portion 21b are integrally formed.

The lower mold 22 is arranged separately in a direction orthogonal to the mold clamping direction in which the upper mold 21 and the lower mold 22 are brought into contact with each other, and has a cavity forming portion 22a having a cavity forming surface on the mold clamping direction side. And a separation mold in which a cavity is defined by a cavity side plate portion 22b having a cavity forming surface surrounding the cavity forming surface adjacent to the cavity forming portion 22a. The mirror surface is formed on one or both of the cavity forming surfaces of the cavity forming portions 21a and 22a.

Outside the upper mold 21 and the lower mold 22, there are provided mold temperature control units 27 and 28 for holding the upper mold 21 and the lower mold 22 and adjusting the temperature of the mold. This mold temperature controller 2
7 and 28 are provided with both heater units 27a and 28a for heating and cooling units 27b and 28b for cooling, and by appropriately selecting the heater unit and the cooling unit, the mold can be quickly brought to a desired temperature. Can be adjusted. And this mold temperature controller
Outside of 27 and 28, they are supported by upper and lower die plates 31 and 32 via heat insulating plates 29 and 30, respectively.

The upper and lower die plates 31 and 32 are further connected to a press machine (not shown) for clamping the upper die 21 and the lower die 22 at a predetermined pressure during molding from the upper and lower clamping directions. . On both sides of the lower mold 22, a mold clamping mechanism 33 for clamping the lower mold 22 from a clamping direction orthogonal to the mold clamping direction is provided, and this mold clamping mechanism 33 is hydraulically, pneumatically or by using an electric motor or the like. A uniform tightening force can be obtained, and these can be appropriately selected according to the shape of the molded product, the size of the mold, and the tightening force.

A compression spring (elastic member) 34 is interposed between the cavity forming portion 22a and the cavity side plate portion 22b, and the compression spring 34 is moved by the mold clamping mechanism 33 to the cavity forming portion 22a and the cavity side plate. Part 22b
Is compressed when tightened, thereby maintaining the regular cavity shape together with the cavity forming portion 21a and the cavity side plate portion 21b. When the tightening of the mold tightening mechanism 33 is released, the cavity forming portion
A gap is formed between the cavity 22a and the cavity side plate 22b. Further, an elastic member such as rubber may be used instead of the compression spring.

At both ends of the cavity forming portion 22a which are in contact with the cavity side plate portion 22b, concave recesses 35 are provided as engaging portions for engaging with the plastic base material 23.
This gap 35 extends in the same direction as the mold clamping direction of the upper mold 21 and the lower mold 22 as shown in FIG.
It extends over a predetermined length in a direction orthogonal to the moving direction of the cavity side plate portion 22b. In this embodiment, as can be seen from the fact that the cavity forming portion 22a has a long shape, the present invention is applied to an apparatus for forming a long molded product.

The step 35 is formed to have a height of 0.3 mm or more, and the length L1 in the extending direction is formed to be at least 1/2 of the cavity forming surface L of the cavity forming portion 22a as shown in FIG. And is formed to have a surface roughness of Ra = 0.1 μm or less. In FIG. 1, reference numeral 36 denotes a positioning mold provided at the center of the upper mold 21 and having a positioning pin 37. Reference numeral 38 denotes an insertion hole 39 provided at the center of the lower mold 22 and into which the positioning pin 37 is inserted.
Are the positioning dies on which the upper die 21 and the lower die 22 are formed.
When the mold is clamped, the positioning of the cavity is performed.

Next, the operation will be described. First, as a pre-process of performing the aging process in the upper mold 21 and the lower mold 22 in the present embodiment, using an injection mold having substantially the same volume and shape as the cavity of the upper mold 21 and the lower mold 22, Plastic injection molding is performed to form a thermoplastic plastic preform pre-processed to a substantially final shape.

In the present embodiment, the plastic base material was subjected to injection molding by setting the temperature of the injection mold to a temperature equal to or lower than the thermal deformation temperature of the resin, and was cooled and solidified. In addition, internal strain and residual stress exist in the resin, and a difference in density occurs due to molecular orientation.
For this reason, it is necessary to further perform an aging step using the upper mold 21 and the lower mold 22 of the present embodiment using the plastic base material obtained in the above-described injection molding step to finally form.

Then, the upper mold 21 and the lower mold 22 are opened up and down, and the preformed thermoplastic plastic base material 23 is inserted into the cavity. At this time, since a cavity is formed in the cavity forming portion 22a and the cavity side plate portion 22b by the repulsive force of the compression spring 24, the plastic base material 23 can be easily inserted. Next, the mold clamping mechanism
Using 33, the cavity forming portion 22a and the cavity side plate portion 22b, which are the lower mold 22, are tightened from both sides with a predetermined pressure.
For this reason, by compressing the compression spring 15, the regular shape of the cavity is maintained, and the occurrence of burrs during molding is suppressed.

Next, the mold is clamped at a predetermined pressure from the mold clamping direction using a press machine.
The upper mold 21 and the lower mold 22 are heated using the heater units 27a and 28a for heating 28, the plastic base material 23 is heated to a glass transition temperature or higher, and an internal pressure is generated by melting and expanding the resin in the cavity. The plastic base material 23 is pressed against the mirror surface formed in the cavity and transferred. At this time, an aging process for removing internal strain, residual stress, and molecular orientation of the plastic base material 23 is performed. After that, while the temperature difference between the internal temperature and the surface temperature of the plastic base material 23 is minimized so that the internal strain, residual stress, and molecular orientation do not occur, the cooling portion 27a, 28a gradually cools the plastic base material 23, and the cavity is cooled. Internal pressure is atmospheric pressure (1kgf / cm2)
And the upper mold 21 and the lower mold 22 are opened at a temperature at which the resin temperature is equal to or lower than the heat deformation temperature.

Next, when the fastening of the mold fastening mechanism 33 is released, a repulsive force of the compression spring 34 is generated, so that a gap is formed between the cavity forming portion 22a and the cavity side plate portion 22b, and the final molded product 23 is formed. Is separated from the lower mold 22 and can be easily taken out. At this time, since the molded product 23 is engaged with the gap 35, the molded product 23 is fixed to the cavity forming portion 22a, and the adjacent cavity side plate portion 22
b does not move to either side.

As described above, in the present embodiment, since the notches 35 for engaging with the plastic base material 23 are provided at both ends of the cavity forming portion 22a in contact with the cavity side plate portion 22b, the cavity forming portion 22a is formed by the repulsive force of the compression spring 34. When the cavity 22a and the cavity side plate portion 22b are separated from each other, the molded product 23 can be engaged with the gap 35 of the cavity forming portion 22a, and the molded product 23 slides on the cavity forming portion 22a and is adjacent to the cavity side plate portion. 22b can be prevented from sticking to any one of them.

As a result, when the molded product 23 is taken out,
The mold release of the molded article 23 can be easily performed, and the deformation of the molded product 23 and the deterioration of the surface accuracy at the time of mold release can be prevented. Further, the height of the step 35 is formed to be 0.3 mm or more, and the length L1 in the extending direction of the step 35 is formed to be at least 1/2 of the cavity forming surface L of the cavity forming portion 22a. Thus, the molded product 23 can be reliably prevented from slipping on the cavity forming portion 22a.

Since the surface roughness of the step 35 is set to Ra = 0.1 μm or less, the molded article 23 is not
It is possible to prevent it from sticking firmly to 35
The mold release of the molded article 23 can be easily performed, and the deformation of the molded product 23 and the deterioration of the surface accuracy at the time of mold release can be reliably prevented. In the present embodiment, the concave gap 35 is provided, but the invention is not limited thereto, and a convex gap 41 may be provided as shown in FIG. Again, this difference
The height of the step 41 is formed to be 0.3 mm or more, the length L1 of the step 41 in the extending direction is formed to be at least 1/2 of the cavity forming surface L of the cavity forming portion 22a, and the surface roughness is Ra = Needless to say, it is formed to 0.1 μm or less.

In addition, when the difference 35 or 41 cannot be formed due to the restriction of the shape of the molded product 23, as shown in FIG. 6, a plastic mother is provided at both ends of the cavity forming portion 22a in contact with the cavity side plate portion 22b. A curved portion 42 that engages with the member 23 may be provided. In this case, if the difference in height from the bottom surface of the cavity forming portion 22a is formed to be 0.3 mm or more, the same effect as in the first embodiment can be obtained.

When the difference 35 or 41 cannot be formed due to the restriction of the shape of the molded product 23, as shown in FIG. 7, the plastic base material 23 is attached to both ends of the cavity forming portion 22a in contact with the cavity side plate portion 22b. Even if the C chamfered portion 43 to be engaged is provided, the same effect as in the first embodiment can be obtained. Also in this case, the height of the C-chamfered portion 43 is formed to be 0.3 mm or more, and the length L1 in the extending direction of the step 41 is formed to be 以上 or more of the cavity forming surface L of the cavity forming portion.
Needless to say, the surface roughness is formed to be Ra = 0.1 μm or less.

When forming the C chamfered portion 43,
As shown in FIG. 8, if the bottom of the chamfered portion is flattened beforehand and chamfered (indicated by X), and then the C chamfering process is performed, the processing accuracy of the edge portion is easily obtained, and the generation of burrs can be prevented. it can. In addition, in the present embodiment, since there are a plurality of cavities, the cut 35 or 41 and the curved surface portions 42 and C are provided on both sides of each cavity forming portion 22b according to the shape of the molded product.
The chamfered portions 43 may be formed in an optimal combination.

Further, in this embodiment, an example is shown in which the long molded product 23 is formed by the long cavity forming portions 21a and 22a. However, in the case of forming a cylindrical molded product, FIG. As shown in (5), a cylindrical cavity forming portion 44 may be used, and a cavity side plate portion 45 may be provided adjacent to the cavity forming portion 44 so as to surround the cavity forming portion 44.

FIGS. 10 and 11 are views showing a second embodiment of the plastic molding apparatus according to the present invention, and correspond to any one of claims 12 to 15. In the present embodiment, the position of the engaging portion formed in the cavity forming portion is the first position.
Since the other configuration is the same as that of the first embodiment except for the configuration of the first embodiment, only the characteristic portions are illustrated. In the present embodiment, projections 52 and C chamfers 53 are provided at both ends of the cavity forming portion 51 in the extending direction outside the cavity forming surface L as engaging portions for engaging with the plastic base material 23.

In this embodiment, the end face 51b formed at a position higher than the cavity forming surface L via the tapered surface 51a is continuous with the cavity forming surface L of the cavity forming portion 51, and the cavity side plate of the tapered surface 51a is formed. C-chamfered portions 53 are formed at both ends 51b in contact with the portion 22b, and projections 52 are formed at both ends 51b. Reference numeral 54 denotes a C chamfer.

With this configuration, the same effects as those of the first embodiment can be obtained. Further, in the present embodiment, since the protrusion 52 and the C chamfered portion 53 are formed at both ends in the extending direction of the cavity forming portion 51, when molding a long or thin deformable molded product such as a long or thin one. The product can be prevented from being deformed. Although not shown, a similar effect can be obtained by forming a convex or concave difference having a height difference from the cavity forming surface L at both ends of the cavity forming portion 51 in the extending direction.

[0053]

According to the present invention, claims 1, 2, 3, 4, 6, 7, 8, 1
According to the inventions described in 0 and 11, the molded product is released when the fastening of the cavity forming portion and the cavity side plate portion by the mold clamping mechanism is released, and the cavity forming portion and the cavity side plate portion are separated by the repulsive force of the elastic member. Is engaged with the engaging portion of the cavity forming portion, and the molded product can be prevented from slipping on the cavity forming portion and coming into close contact with one of the adjacent cavity side plate portions. As a result, it is possible to easily release the molded product at the time of taking out the molded product, and it is possible to prevent the molded product from being deformed and the surface accuracy from deteriorating at the time of release.

According to the fifth and ninth aspects of the present invention, it is possible to prevent the molded article from firmly eroding due to a difference when the molded article is taken out, and it is possible to easily release the molded article from the mold. In addition, it is possible to reliably prevent the molded product from being deformed and the surface accuracy from deteriorating when the mold is released. Claim 12,
According to the invention described in 13, 14, 15, in that case, the fastening of the cavity forming portion and the cavity side plate portion by the mold clamping mechanism is released, and the cavity forming portion and the cavity side plate portion are separated by the repulsive force of the elastic member. sometimes,
The molded product is engaged with the engaging portion of the cavity forming portion, and it is possible to prevent the molded product from sliding on the cavity forming portion and coming into close contact with one of the adjacent cavity side plates.
As a result, it is possible to easily release the molded product at the time of taking out the molded product, and it is possible to prevent the molded product from being deformed and the surface accuracy from deteriorating at the time of release.

Further, since the engaging portions are formed at both ends in the extending direction of the cavity forming portion, it is possible to prevent the molded product from being deformed when molding a long or thin-shaped easily deformable product. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the configuration of a first embodiment of a plastic molding apparatus according to the present invention.

FIG. 2 is a cross-sectional view of the separation mold according to the first embodiment.

FIG. 3 is a cross-sectional view of a joining portion between a cavity forming portion and a plastic base material according to the first embodiment.

FIG. 4 is a perspective view of a cavity forming section according to the first embodiment.

FIG. 5 is a view showing another aspect of the cavity forming section of the first embodiment.

FIG. 6 is a view showing another aspect of the cavity forming section of the first embodiment.

FIG. 7 is a view showing another aspect of the cavity forming section of the first embodiment.

FIG. 8 is a view showing another mode of the cavity forming section of the first embodiment, and is a view showing the chamfering immediately before forming the C chamfered section.

FIG. 9 is a top view showing another aspect of the cavity forming portion and the cavity side plate portion of the first embodiment, and FIG. 9B is a cross-sectional view taken along line XX of FIG. 9A.

FIG. 10 is a view showing a second embodiment of the plastic molding apparatus according to the present invention, and is a perspective view of a cavity forming portion thereof.

FIG. 11 is a cross-sectional view taken in the direction of arrows AA in FIG. 10;

FIG. 12 is a configuration sectional view of a conventional plastic molding apparatus.

FIG. 13 is a cross-sectional view illustrating a state of a separation mold when a mold clamping mechanism of a lower mold is released in a conventional plastic molding apparatus.

[Explanation of symbols]

 21 Upper die (die) 22 Lower die (die) 22a, 44 Cavity forming part 22b, 45 Cavity side plate part 23 Plastic base material 33 Mold clamping mechanism 34 Compression spring (elastic member) 35, 41 Part) 42 Curved surface part (engagement part) 43, 53 C chamfer part 52 Projection (engagement part)

Claims (15)

[Claims] 1. A plastic having a pair of molds having at least one cavity having at least one mirror surface, wherein the shape and the volume of the cavity are substantially the same as those of the cavity by injection molding in advance in the cavity. After the base material was inserted and clamped, the plastic base material was heated and melted above its glass transition temperature to generate an internal resin pressure, and then gradually cooled to transfer the mirror surface to the plastic base material. In a plastic molding die, at least one of the pair of dies is arranged separately in a direction orthogonal to a die clamping direction in which the dies are brought into contact with each other, and a cavity forming part having a cavity forming surface on the die clamping direction side; A cavity is formed by a cavity side plate having a cavity forming surface adjacent to the cavity forming portion and surrounding the cavity forming surface. A mold, a mold clamping mechanism for clamping the mold from both sides in a direction substantially orthogonal to the mold clamping direction, and an interposition between a cavity forming portion and a cavity side plate of the mold. And an elastic member that is compressed to hold a regular cavity shape when tightened by the mold tightening mechanism, and separates the cavity forming portion and the cavity side plate portion by a repulsive force when the tightening is released. A plastic molding apparatus comprising: an engagement portion that engages with a plastic base material at both end portions in contact with a cavity side plate portion. 2. The method according to claim 1, wherein the engaging portion extends in the same direction as the mold clamping direction and includes a gap extending over a predetermined length in a direction orthogonal to the moving direction of the separation mold. The plastic molding apparatus according to claim 1, wherein 3. The plastic molding apparatus according to claim 2, wherein the height of the step is formed to be 0.3 mm or more. 4. The plastic molding apparatus according to claim 2, wherein the length of the step in the extending direction is formed to be at least half of the cavity forming surface of the cavity forming portion. 5. The plastic molding apparatus according to claim 2, wherein the surface roughness of said step is Ra = 0.1 μm or less. 6. The method according to claim 6, wherein said engaging portion comprises a C-chamfered portion extending in the same direction as said mold clamping direction and extending for a predetermined length in a direction orthogonal to the direction of movement of said separation mold. The plastic molding apparatus according to claim 1, wherein: 7. The plastic molding apparatus according to claim 6, wherein the size of the C-chamfered portion is formed to be 0.3 mm or more. 8. The plastic molding apparatus according to claim 6, wherein the length of the C-chamfered portion in the extending direction is formed to be at least half of the cavity forming surface of the cavity forming portion. 9. The surface roughness of the chamfered portion is Ra = 0.1 μm.
The plastic molding apparatus according to any one of claims 6 to 8, wherein: 10. The method according to claim 1, wherein the engaging portion includes a curved portion extending in a direction perpendicular to a direction in which the separation mold moves and extending in the same direction as the mold clamping direction. The plastic molding apparatus according to claim 1, wherein 11. The plastic molding apparatus according to claim 10, wherein a difference in height between the curved surface portion and the bottom surface of the cavity forming portion is 0.3 mm or more. 12. A plastic having a pair of molds having at least one cavity having at least one mirror surface, and having a shape and a volume substantially the same as those of the cavities previously formed by injection molding in the cavities. After the base material was inserted and clamped, the plastic base material was heated and melted above its glass transition temperature to generate an internal resin pressure, and then gradually cooled to transfer the mirror surface to the plastic base material. In a plastic molding die, at least one of the pair of dies is arranged separately in a direction orthogonal to a die clamping direction in which the dies are brought into contact with each other, and a cavity forming part having a cavity forming surface on the die clamping direction side; A cavity is formed by a cavity side plate having a cavity forming surface adjacent to the cavity forming portion and surrounding the cavity forming surface. A separating mold to be defined, a mold clamping mechanism for clamping the separating mold from both sides in a direction substantially orthogonal to the mold clamping direction, and a mold interposed between a cavity forming portion and a cavity side plate portion of the separating mold. An elastic member that is compressed to maintain a normal cavity shape when tightened by the mold tightening mechanism, and separates the cavity forming portion and the cavity side plate portion by a repulsive force when the tightening is released. A plastic molding apparatus, comprising: an engaging portion that engages with a plastic base material at both ends in the existing direction. 13. The plastic molding apparatus according to claim 12, wherein the engaging portion comprises a protrusion protruding from the cavity forming portion. 14. The plastic molding apparatus according to claim 12, wherein the engaging portion comprises a gap having a height difference from a cavity forming surface. 15. The plastic molding apparatus according to claim 12, wherein the engaging portion comprises a C chamfer.