JPH08244038A - Mold apparatus for molding resin - Google Patents

Abstract

PURPOSE: To prevent the generation of mold release inferiority between an upper fixed mold and a molded product by providing the wall part of the cavity for forming the outer peripheral part of the molded product to a movable mold part and forming an undercut part to the wall part. CONSTITUTION: An undercut part 29A is formed to the circumferential part of a disc-shaped cavity 30B, that is, the circumferential wall of the circumferential part 29 of a movable mold 20. Therefore, a projection part 40A is formed to the circumferential part of the molded product 40 molded in the disk-shaped cavity 30B corresponding to the undercut part 29A and chamferring parts 40B are formed on both sides of the projection part 40A. The projection part 40A of the molded product 40 is engaged with the undercut part 29A of the circumferential part 29 of the movable mold 20. When the lower movable mold 20 is moved, that is, a disc part 27 and the circumferential part 29 are moved by this engagement, the molded product 40 is moved along with them and demolded from a stamper 35.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molding die apparatus suitable for use in the production of a relatively thin disk-shaped resin molded product such as an optical disk or a magneto-optical disk.

[0002]

2. Description of the Related Art The construction and operation of a first example of a conventional disk molding die apparatus will be described with reference to FIGS.
As shown in FIG. 6A, the disc molding die device has an upper fixed die 10 and a lower movable die 20 arranged so as to oppose the fixed die. Molds 10, 2
The engagement of 0 forms a cavity 30 between them.

The upper fixed mold 10 has a central core portion 11 and a sleeve-like member 13 fixedly mounted on the outer side of the core portion 11. A runner 11A is connected to the core portion 11, and the liquid resin is introduced into the cavity 30 from the runner 11A.

The upper fixed mold 10 further includes three support members 15, 17, 19 and three support members 15, 17,
And a thin metal disk-shaped stamper 35 supported by 19. The stamper 35 is supported so that the surface on which information is recorded faces the cavity 30. The stamper 35 is arranged on the central support member 17, and the stamper 3
The edge of the center hole 5 is supported by the inner support member 15, and the outer edge of the stamper 35 is supported by the outer support member 19.

The lower movable mold 20 has a central core portion, that is, a punch 21, a pin-shaped projecting member 22 arranged in the center hole thereof, and a tubular projecting member 23 arranged outside. The lower movable mold 20 further has a disk portion 27 arranged outside the protruding member 23 and a circumferential portion 29 further outside.

The cavity 30 has two core parts 11 and 2.
Center cavity 30A and stamper 3 formed between
5 and a disk-shaped cavity 30B formed between the disk portion 27. The central cavity 30A and the disk-shaped cavity 30B are connected at a slight interval.

As shown in FIG. 6A, two molds 10 and 2 are provided.
The resin is introduced into the cavity 30 when the mold is closed when 0 is engaged. Resin is center cavity 30A from runner 11A
To the disk-shaped cavity 30B.

As shown in FIG. 6B, the lower core portion, that is, the punch 21, moves upward during curing of the resin, the central cavity 30A and the disk-shaped cavity 30B are divided from each other, and the resin inside the cavity 30 is separated. It is separated into two.
The resin is cured and the molded product 40 is formed in the disk-shaped cavity 30B.

As shown in FIG. 7A, the mold releasing air is blown from the upper fixed mold 10 before the mold releasing is started. Such release air is, for example, the sleeve-shaped member 13
It is blown out from a gap between the support member 15 and the support member 15. Next, the lower movable mold 20 moves downward, and the molded product 40 is completely released from the stamper 35. Blowing the release air,
This is because when the lower movable mold 20 moves, a vacuum is generated between the lower surface of the stamper 35 and the upper surface of the molded product 40, which have been in contact with each other up to that point, to prevent mold release failure.

Finally, as shown in FIG. 7B, the tubular protruding member 23 moves upward, and the molded product 40 is completely released from the lower movable mold 20. At the same time, the pin-shaped protrusion member 22 in the punch 21 moves upward and the resin 40A in the central cavity 30A is taken out.

The configuration and operation of the second example of the conventional disk molding die device will be described with reference to FIGS. 8 and 9. As shown in FIG. 8A, the disc molding die device has an upper fixed die 60 and a lower movable die 70 arranged so as to oppose the fixed die, and the two die Mold 60, 70
By engaging with each other, a cavity 80 is formed between them.

The upper fixed die 60 has a central core portion 61, a sleeve member 13 fixedly mounted on the outer side thereof, a disc portion 67 on the outer side thereof, and a circumferential portion 69 on the outer side thereof. A runner 61A is formed on the core portion 61,
Liquid resin is introduced into the cavity 80 from the runner 61A.

The lower movable mold 70 has a central core portion, that is, a punch 71, a pin-shaped projecting member 72 arranged in the center hole thereof, and a tubular projecting member 73 arranged outside. The lower movable mold 70 further has a thin metal disk-shaped stamper 85 arranged outside the protruding member 73. The stamper 85 has three support members 7 such that the surface on which information is recorded faces the cavity 80.
It is supported by 5, 77, 79. That is, the stamper 85 is disposed on the central support member 77, and the stamper 8 is
The edge of the center hole 5 is supported by the inner support member 75, and the outer edge of the stamper 85 is supported by the outer support member 79.

The cavity 80 has two core portions 61, 7
Center cavity 80A and stamper 8 formed between
5 and a disk-shaped cavity 80B formed between the disk portion 67. The central cavity 80A and the disk-shaped cavity 80B are connected at a slight interval.

As shown in FIG. 8A, two molds 60, 7 are provided.
The resin is introduced into the cavity 80 when the mold is closed when 0 is engaged. Resin is center cavity 80A from runner 61A
To the disk-shaped cavity 80B.

As shown in FIG. 8B, during curing of the resin, the lower core portion, that is, the punch 71 moves upward, the central cavity 80A and the disk-shaped cavity 80B are divided from each other, and the resin in the cavity 80 is separated. It is separated into two.
The resin is hardened and a molded product 90 is formed in the disk-shaped cavity 80B.

As shown in FIG. 9A, the releasing air is blown from the upper fixed mold 60 before the releasing is started. Such release air is, for example, the sleeve-shaped member 63.
And is blown out from the gap between the disc portion 67. Next, the lower movable mold 70 moves downward, and the molded product 90 is completely released from the disc portion 67. The release air is blown in. When the lower movable mold 70 moves, a vacuum is generated between the lower surface of the disk portion 67 and the upper surface of the molded product 90, which have been in contact with each other until then, causing a defective release. This is to prevent this.

Finally, as shown in FIG. 9B, the tubular protruding member 73 moves upward, and the molded product 90 is completely released from the lower movable mold 70. At the same time, the pin-shaped protrusion member 72 in the punch 71 moves upward and the resin 90A in the central cavity 80A is taken out.

[0019]

In the conventional mold device described with reference to FIGS. 6 and 7 and FIGS. 8 and 9, when the lower movable molds 20 and 70 move when the molds are opened. The molded products 40 and 90 are released from the upper fixed molds 10 and 60 and move together with the movable molds 20 and 70.

However, the molded products 40 and 90 are not completely supported by the movable molds 20 and 70 with sufficient force. Therefore, the molded products 40, 9
0 is partially separated from the movable molds 20 and 70, and the fixed mold 1
Occurrence of being drawn to the 0, 60 side. That is, the mold release between the upper fixed molds 10 and 60 and the molded products 40 and 90 may be interrupted on the way to cause mold release failure.

At the start of mold release, the upper fixed molds 10 and 6
Compressed air or the like for promoting mold release is blown between 0 and the molded products 40 and 90. This is because when the lower movable molds 20, 70 move, the upper fixed molds 10, 60 and the molded products 40, 9 are moved.
This is because the vacuum generated during 0 is broken and mold release is promoted.

However, even if compressed air or the like for promoting mold release is used in the conventional apparatus, it is not possible to completely prevent mold release defects.

In view of the above point, the present invention has an object to provide a mold device which does not cause a mold release defect between the upper fixed mold 10 and 60 and the molded product 40 and 90.

[0024]

According to the present invention, a resin molding having a fixed mold part and a movable mold part and having a cavity formed therein by the engagement of the two mold parts. In the mold device for use, the movable mold part has a wall part of the cavity for forming an outer peripheral part of a molded product,
An undercut portion is formed on the wall portion.

According to the present invention, the resin molding die device is characterized in that a protrusion member for releasing the molded product from the movable mold portion is provided.

According to the present invention, in the resin molding die device, the movable mold part has a cylindrical wall part of the cavity for forming the center hole of the molded product, and the wall part has an under wall. It is characterized in that a cut portion is formed.

According to the present invention, in the resin molding die device, a stamper is attached to either one of the two die parts, and the stamper is arranged such that the surface on which information is recorded faces the inside of the cavity. It is characterized by being.

[0028]

According to the present invention, the peripheral part of the molded product is engaged with the undercut part formed on the movable mold, and the peripheral part of the molded product is supported so as not to move with respect to the movable mold. Has been done. Therefore, the molded product is released better than the fixed mold.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of a mold apparatus according to the present invention will be described with reference to FIG. FIG. 1 shows the circumference of the cavities 30B, 80B of the mold device according to the invention. Cavity 3
Molded products 40 and 90 are formed in 0B and 80B.

FIG. 1A shows a first example of the mold apparatus of the present invention. This first example corresponds to the first example of the conventional mold device shown in FIGS. 6 and 7, and the stamper 35 is supported on the upper fixed mold 10 side. Compared with the first example of the conventional mold device, the mold device of this example has a cavity 30B.
The configuration may be the same except for the shape of the circumferential portion of. Therefore, corresponding parts are designated by the same reference numerals.

In FIG. 1A, supporting members 17 and 19 for supporting the stamper 35 are shown, and a disk portion 27 and a circumferential portion 29 of the lower movable mold 20 are shown. Stamper 3
5 and the lower movable mold 20 between the disk-shaped cavity 3
0B is formed. Such a disk-shaped cavity 3
A molded product 40 is formed in 0B.

As shown, the disk-shaped cavity 30
An undercut portion 29A is formed on the circumferential portion of B, that is, on the circumferential wall of the circumferential portion 29 of the movable mold 20. Therefore,
Molded product 40 molded in the disk-shaped cavity 30B
A projecting portion 40A is formed on the circumferential portion corresponding to the undercut portion 29A, and chamfered portions 40B are formed on both sides of the projecting portion 40A.

The protrusion 40A of the molded product 40 is a movable mold 20.
Is engaged with the undercut portion 29A of the circumferential portion 29 of the.
When the lower movable mold 20, that is, the disk portion 27 and the circumferential portion 29 move due to such engagement, the molded product 40 moves together with it and is released from the stamper 35.

FIG. 1B shows a second example of the mold apparatus of the present invention. This second example corresponds to the second example of the conventional mold device shown in FIGS. 8 and 9, and the stamper 185 is supported on the lower movable mold 170 side. In FIG. 1B, support members 177 and 179 that support the stamper 185 are illustrated, and the disk portion 167 of the upper fixed mold 160 is illustrated. A disk-shaped cavity 180B is formed between the stamper 185 and the upper fixed mold 160.
A molded product 190 is placed in the disc-shaped cavity 180B.
Are formed.

As shown, the disk-shaped cavity 18
0B circumference part, that is, the support member 179 of the movable mold 170.
An undercut portion 179A is formed on the circumferential wall of. Therefore, the undercut portion 1 is formed on the circumferential portion of the molded product 190 molded in the disk-shaped cavity 180B.
Protrusions 190A are formed corresponding to 79A, and chamfers 190B are formed on both sides of the protrusions 190A.

The protrusion 190A of the molded product 190 is engaged with the undercut portion 179A of the support member 179 of the movable mold 170. By such engagement, the lower movable mold 17
0, that is, when the support member 179 moves, the molded product 190
Moves with it, and is released from the upper fixed mold 160, that is, the disk portion 167.

In the above example, the lower movable molds 20, 17
No. 0 circumferential portion 29 or the circumferential wall of the support member 179 is formed with annularly extending undercut portions 29A, 179A, and the protrusions 40A, 190A of the molded products 40, 190 engage with the undercut portions 29A, 179A. By doing so, both are able to move together. However, as long as it provides such a function, the movable molds 20, 170
The circumferential cut 29 or the undercut parts 29A and 179A provided on the support member 179 may have any shape.

The operation of the first example of the disk molding die apparatus according to the present invention will be described below with reference to FIGS.
The example shown in FIGS. 2 and 3 is the same as the example shown in FIG. 1A, and corresponds to the conventional example of FIGS. 6 and 7. Therefore, corresponding parts are designated by the same reference numerals.

As shown in FIG. 2A, two molds 10, 2 are provided.
The resin is introduced into the cavity 30 when the mold is closed when 0 is engaged. Resin is center cavity 30A from runner 11A
To the disk-shaped cavity 30B.

As shown in FIG. 2B, during curing of the resin, the lower core portion, that is, the punch 21, moves upward, the central cavity 30A and the disk-shaped cavity 30B are divided from each other, and the resin in the cavity 30 is separated. It is separated into two.
The resin is cured and the molded product 40 is formed in the disk-shaped cavity 30B.

As shown in FIG. 3A, releasing is started and the lower movable mold 20 moves downward. As described with reference to FIG. 1A, the outer peripheral portion of the molded product 40 is securely supported by the circumferential portion 29 of the movable mold 20, and the molded product 40 moves together with the movable mold 20. Therefore, a part of the molded product 40 does not adhere to the fixed mold 10 side, that is, the stamper 35 to cause a mold release defect.

In this example, since the molded product 40 is securely supported by the circumferential portion 29, good mold release can be achieved without the need to blow air for promoting mold release. However, when the lower movable mold 20 moves downward, a vacuum is generated between the lower surface of the stamper 35 and the upper surface of the molded product 40, which have been in contact with each other until then. Etc. may be blown. Thereby, the mold release can be performed more smoothly and favorably.

Finally, as shown in FIG. 3B, the movable mold 20
The outer peripheral portion of the molded product 40 moves along the circumference 2
It deviates from 9. That is, the protrusion 40 on the outer peripheral portion of the molded product 40.
The engagement between A and the undercut portion 29A of the circumferential portion 29 is released. Further, the tubular protruding member 23 moves upward, and the molded product 40 is completely released from the lower movable mold 20. At the same time, a pin-shaped protruding member 22 in the punch 21
Moves upward and the resin in the central cavity 30A is taken out.

Next, the operation of the second example of the disk molding die apparatus according to the present invention will be described with reference to FIGS. 4 and 5.
The example shown in FIGS. 4 and 5 is the same as the example shown in FIG. 1B, and corresponding parts are denoted by the same reference numerals. As shown in FIG. 4A, the upper fixed mold 160 has a core portion 161, a sleeve-shaped member 163, and a disc portion 167, and the runner 161A is connected to the core portion 161.

The lower movable mold 170 has a central core portion, that is, a punch 171, a pin-shaped projecting member 172 arranged in the center hole, and a tubular projecting member 173 arranged outside.

The movable mold 170 on the lower side further includes the stamper 18
5 and two support members 175, 177 and movable support member 17
9 and the stamper 185 has such a support member 175,
It is supported by 177 and 179. That is, the edge of the center hole of the stamper 185 is supported by the inner support member 175, and the outer portion of the stamper 185 is suction-supported by the suction device 178 provided on the support member 177.

The resin is introduced into the cavity 180 when the two molds 160 and 170 are engaged and the mold is closed. The resin is guided from the runner 161A to the central cavity 180A,
Further, it is guided to the disk-shaped cavity 180B.

As shown in FIG. 4B, during curing of the resin, the lower core portion, that is, the punch 171 moves upward, the central cavity 180A and the disk-shaped cavity 180B are divided from each other, and the resin in the cavity 180 is separated. It is separated into two. The resin hardens and the disk-shaped cavity 180B
A molded product 190 is formed therein.

As shown in FIG. 5A, release is started and the lower movable mold 170 moves downward. As described with reference to FIG. 1B, the outer peripheral portion of the molded product 190 has the movable mold 17
It is surely supported by the movable support member 179 of 0, and the molded product 190 moves together with the movable mold 170. Therefore, a part of the molded product 170 is on the fixed mold 160 side, that is,
It does not adhere to the disc portion 167 and cause a mold release defect.

In this example, as in the first example, when the lower movable mold 20 moves downward, it is placed between the lower surface of the disk portion 167 and the upper surface of the molded product 190 which have been in contact with each other until then. Since a vacuum is generated, air or the like may be blown in to break the vacuum. Thereby, the mold release can be performed more smoothly and favorably.

Finally, as shown in FIG. 5B, the tubular projecting member 173 and the movable supporting member 179 move upward, and the molded product 190 moves to the lower movable mold 170, that is, the stamper 1.
Completely release from 85. At the same time, the pin-shaped protruding member 172 in the punch 171 moves upward and the resin in the central cavity 180A is taken out. Further, although not shown, the movable supporting member 179 of the movable mold 170 moves and the outer peripheral portion of the molded product 190 comes off the movable supporting member 179. That is, the engagement between the protruding portion 190A on the outer peripheral portion of the molded product 190 and the undercut portion 179A of the movable support member 179 is released.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the invention described in the claims. Will be understood by those skilled in the art.

In the above example, the undercut portion 29 is formed on the circumferential portion 29 of the movable mold 20 or 170 or the movable support member 179.
A and 179A are formed, and the circumferential portions of the molded products 40 and 190 are engaged and supported by the undercut portions 29A and 179A. However, an appropriate undercut portion may be provided on the core portions 21, 171 side of the movable molds 20, 170 to support the inner edges of the center holes of the molded products 40, 190.

As a result, the molded products 40 and 190 are moved to the movable mold 2 on both sides of the edge of the circumference and the edge of the central hole.
Since it is fixedly supported by 0, 170, the molded product 40, 1
90 is completely released from the upper fixed molds 10 and 160 at the start of mold release.

[0055]

According to the present invention, in a mold apparatus for molding a disk, there is an advantage that the mold release between the mold and the molded product is not interrupted on the way to cause a mold release defect.

According to the present invention, it is possible to prevent a mold releasing defect with a simple device in a mold device for molding a disk.

[Brief description of drawings]

FIG. 1 is a partial detailed view of a mold apparatus according to the present invention.

FIG. 2 is an explanatory diagram for explaining the operation of the first example of the mold apparatus according to the present invention.

FIG. 3 is an explanatory diagram for explaining the operation of the first example of the mold apparatus according to the present invention.

FIG. 4 is an explanatory diagram for explaining the operation of the second example of the mold apparatus according to the present invention.

FIG. 5 is an explanatory diagram for explaining the operation of the second example of the mold apparatus according to the present invention.

FIG. 6 is an explanatory diagram for explaining the operation of the first example of the conventional mold device.

FIG. 7 is an explanatory diagram for explaining the operation of the first example of the conventional mold device.

FIG. 8 is an explanatory diagram for explaining the operation of the second example of the conventional mold device.

FIG. 9 is an explanatory diagram for explaining the operation of the second example of the conventional mold device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Fixed mold 11 Core part 11A Runner 13 Sleeve member 15 Support member 15A Air blowout port 17, 19 Support member 20 Movable mold 21 Core part 22, 23 Protrusion member 27 Disk part 29 Circumferential part 29A Undercut part 30 Cavity 30A center cavity 30B disk-shaped cavity 35 stamper 40 molded product 40A protrusion 40B chamfer 60 fixed mold 61 core 61A runner 63 sleeve member 67 disk 67A air outlet 69 circumferential 69A undercut 70 movable mold 71 Core Part 72, 73 Protruding Member 75, 77, 79 Supporting Member 80 Cavity 80A Central Cavity 80B Disk Cavity 85 Stamper 90 Molded Product 90A Projection 90B Chamfer 160 Fixed Mold 161 Co Part 161A Runner 163 Sleeve member 167 Disk part 167A Air blowout port 170 Movable mold 171 Core part 172, 173 Extruding member 175, 177 Support member 178 Suction device 179 Support member 179A Undercut part 180 Cavity 180A Central cavity 180B Disk cavity 185 Stamper 190 Molded product 190A Projection 190B Chamfer

Claims (4)

[Claims] 1. A resin molding die device having a fixed mold part and a movable mold part, wherein a cavity is formed inside when the two mold parts are engaged with each other. The part has a wall part of the cavity for forming an outer peripheral part of a molded product, and an undercut part is formed in the wall part. 2. The resin molding die device according to claim 1, further comprising a protrusion member for releasing the molded product from the movable die part. . 3. The resin molding die apparatus according to claim 1, wherein the movable mold portion has a cylindrical wall portion of the cavity for forming a center hole of the molded article, and the wall. An undercut part is formed in the part, and a resin molding die device. 4. The resin molding die apparatus according to claim 1, 2 or 3, wherein a stamper is attached to either one of the two die parts, and the stamper has a surface on which information is recorded in the cavity. A mold device for resin molding, which is arranged so as to face the.