JPH09225981A - Clamping device for molding disc - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of parts, miniaturizing the whole apparatus including space saving in the direction of entire length and width. SOLUTION: A movable mold 8 to be clamped to the stationary mold 7 held on a stationary die plate 5 is retained on the front part 4a of the clamping ram 4 of a clamping cylinder 2, and the center hole molding mechanism 20 of a disc is provided within the clamping ram 4, and further hydraulic pipings 23, 24 and so forth being communicated to the molding mechanism 20 are installed in a manner projecting outside of the rear part 4b of the clamping raw 4. As a result, the necessity of a movable die plate and a mold opening and closing cylinder is obviated, and outside projection of the clamping cylinder 2 of the hydraulic pipings 23, 24 is avoided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold clamping device, and more particularly to a mold clamping device for molding a disc which is applied to molding an optical disc such as a compact disc or a digital video disc.

[0002]

2. Description of the Related Art A mold clamping device of this type is configured such that a movable die plate holding a movable mold is moved forward with respect to a fixed die plate holding a fixed mold to close and clamp the mold, and then a nozzle is attached to the mold. Molten resin is injected into the mold from the nozzle by touching and molding, and then the injection side is retracted and the mold clamping side is opened to take out the disc as a molded product.

A desired stamper is held on the fixed mold and / or the movable mold.

At this time, the center hole of the disk is formed by cutting a corresponding portion of the disk-shaped semi-molded product into a circular shape in a mold clamped state, projecting the cut piece when the mold is opened, and removing the cut piece outside the mold. . At this time, the center hole forming mechanism is incorporated in the moving die plate, and the driving of the forming mechanism drives related members in the moving mold to form the center hole.

The center hole forming mechanism is driven by hydraulic pressure. Therefore, in the conventional mold clamping device, a pipe for supplying pressure oil to the forming mechanism is provided on the side portion of the movable die plate.

[0006]

However, in the conventional mold clamping device, (1) due to the existence of the movable die plate, a mold opening / closing cylinder attached thereto is required, and the number of parts is increased and the movable die plate is moved. Due to the space being secured, the total length cannot be shortened despite the small movement stroke of the moving die (moving die plate), and (2) the pressure oil is supplied to the side of the moving die plate. Due to the need to secure a space for installing and moving the pipe in the width direction of the device, there is a problem that the size of the entire device is increased.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to reduce the number of parts and to reduce the total length of the device and the space in the width direction. It is an object of the present invention to provide a mold clamping device for disk molding which enables downsizing.

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a mold clamping cylinder and a fixed die plate are connected to each other through a tie bar, and the mold clamping cylinder is connected to the tie bar. In a disk-molding clamping device that applies tension to perform clamping, a moving mold that is clamped by a fixed mold held by the fixed die plate is held at the front part of a mold clamping ram of the mold clamping cylinder. Has been done,
In addition, a center hole forming mechanism for the disc is provided in the mold clamping ram, and a pressure oil pipe communicating with the forming mechanism is provided so as to be led out from a rear portion of the mold clamping ram. I am trying.

Therefore, in the invention described in claim 1, the mold closing, the mold clamping, and the mold opening are directly performed by the mold clamping cylinder without the intermediary of the moving die plate, and the pressure oil supply pipe to the center hole forming mechanism is provided in the mold. It is guided outward from the rear part of the mold clamping ram without protruding outward from the side of the clamping cylinder.

According to a second aspect of the present invention, there is provided the mold clamping device for disk molding according to the first aspect, wherein the mold clamping ram is attached while being prevented from rotating by a guide mechanism that guides axial movement. It is characterized by that.

Therefore, according to the second aspect of the present invention, the mold clamping ram is stopped by the guide mechanism and is moved back and forth while maintaining parallelism with the fixed die plate.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows a mold clamping device 1 as an embodiment of the present invention. In this mold clamping device 1, a mold clamping cylinder 2 and a fixed die plate 5 are connected via a tie bar 6, and a tension is applied to the tie bar 6 by the mold clamping cylinder 2 to perform mold clamping. The movable mold 8 clamped by the fixed mold 7 held by the plate 5 is held by the front portion 4a of the mold clamping ram 4 of the mold clamping cylinder 2, and the center hole molding mechanism 20 of the disk is clamped by the mold. A pressure oil pipe (only the pressure oil pipes 23 and 24 are shown in FIG. 1) provided in the ram 4 and communicating with the center hole forming mechanism 20 is provided so as to be led out from the rear portion 4b of the mold clamping ram 4. It is generally configured.

A desired stamper is held on the fixed mold 7 and / or the movable mold 8.

The mold clamping cylinder 2 is composed of a cylinder block 3 whose lower part is fixed to a frame 12, and a mold clamping ram 4 which is slidably mounted through the cylinder block 3 so as to be parallel to the frame 12. It is configured. The mold clamping ram 4 includes a piston portion 41 formed in a large diameter in a substantially central portion,
The piston portion 41 is formed with a front rod portion 42 and a rear rod portion 43 each having a small diameter on both sides,
A seal member 10 is interposed between the front and rear rod portions 42 and 43 and the cylinder block 3 so as to be slidable in the axial direction. By mounting the mold clamping ram 4, a front pressure chamber 31 and a rear pressure chamber 32 are formed on both sides of the piston portion 41 in the cylinder block 3 (see FIGS. 1 and 2).

Preferably, as shown in FIG. 1, the bush 9 for guiding the slide of the mold clamping ram 4 is attached to the cylinder block 3.
It can be provided in. In this embodiment, two bushes 9 are provided so as to guide the front and rear rod parts 42 and 43, and the mold clamping ram 4 is provided with these two bushes 9, 9.
It is supported at two points and can slide with a high degree of parallelism.

Further, more preferably, as shown in FIG. 1, the mold clamping ram 4 is attached so as to be stopped by a guide mechanism 13 for guiding the axial movement.

The guide mechanism 13 is fixed to the guide pin 14 axially protruding from the rear portion 4b of the cylinder block 3 and the guide pin 14 fixed to the rear portion 4b of the mold clamping ram 4 protruding outward from the cylinder block 3 toward the rear portion. 14 and a guide plate 15 having a guide hole 15a slidably inserted therein.

In FIG. 1, reference numeral 16 is a nozzle insertion hole into which an injection side nozzle (not shown) is inserted, and reference numeral 11 in FIG. 1 is a stopper of the seal member 10.

Disk center hole forming mechanism 20
Is assembled in the cavity portion 44 formed in the axial direction of the mold clamping ram 4, and the pressure oil pipe including the pipes 23 and 24 is pulled in the cavity portion 44 in the axial direction so that the rear portion of the mold clamping ram 4 is It is provided so as to penetrate the guide plate 15 from 4b and lead out to the outside.

This center hole forming mechanism 20 is shown in FIG.
As shown in FIG. 4, the hydraulic punch 21 and the hydraulic extrusion 2
2 are provided. The hydraulic punch 21 is composed of a punch cylinder portion 21a and a piston portion 21b having a large diameter at the base end portion of the punch cylinder portion 21a. The pressure formed by connecting the blocks 17 and 18 to the piston portion 21b. The punch cylinder portion 21a is mounted in the chamber A, and the punch cylinder portion 21a is penetrated through the block 17 so that the tip of the punch cylinder portion 21a faces the opening of the front portion 4a of the mold clamping ram 4. The hydraulic push-out 22 includes a rod portion 22a and a piston portion 22 having a large diameter at the base end portion of the rod portion 22a.
b and is formed of the piston 22b and the block 1
The rod portion 22a is inserted into the punch cylinder portion 21a of the hydraulic punch 21 while the rod portion 22a is inserted into the pressure chamber B formed by the connection of 8 and 19 and the tip of the rod portion 22a is opened at the opening end of the punch cylinder portion 21a. It is installed in the vicinity. The block 17 is fixed to the mold clamping ram 4 with a screw 27, the block 18 is fixed to the block 17 with a screw 28, and the block 19 is fixed to the block 18 with a screw 29.

The block 17 has a piston portion 21.
Oil passages b and c communicating with each chamber of the pressure chamber A partitioned by b are formed, and the pressure oil pipes 25 and 26 communicate with the oil passages b and c via joints 25a and 26a, respectively. (See FIGS. 3 and 4). The block 18 is formed with an oil passage a communicating with one chamber of the pressure chamber B partitioned by the piston portion 22b, and the block 19 is formed with an oil passage d communicating with the other chamber of the pressure chamber B. In addition, pressure oil pipes 23 and 24 communicate with the oil passages d and c via joints 23a and 24a, respectively (FIGS. 2 and 4).
reference). And these pressure oil pipes 23, 24, 25, 2
6 is provided in the cavity portion 44 in the axial direction so as to extend from the rear portion 4b of the mold clamping ram 4 through the guide plate 15 to the outside.

The disk-molding clamping device 1 assembled as described above operates as follows.

Normal operation can be performed by alternately supplying pressure oil to the front and rear pressure chambers 31, 32.

That is, by supplying pressure oil to the rear pressure chamber 32, the mold clamping ram 4 advances, mold closing and mold clamping are performed, and the injection side nozzle inserted into the nozzle insertion hole 16 in this mold clamping state. Injection molding is performed by injecting a molten resin into the cavity between the two molds 7, 8. After injection molding, by supplying pressure oil to the front pressure chamber 31, the mold clamping ram 4 is retracted, the mold is opened, and the molded product is taken out in this mold opened state.

Normal operation is performed by repeating the forward / backward movement of the mold clamping ram 4 with respect to the fixed die plate 5 as described above. The mold clamping ram 4 during the normal operation moves back and forth with the movement stroke S (see FIGS. 1 to 3).

The center hole forming in this normal operation is
It is performed by driving a related mechanism (not shown) in the movable die 8 by the center hole forming mechanism 20.

That is, the hydraulic punch 21 of the center hole forming mechanism 20 is driven in a mold clamping state to cut the central portion of the disk-shaped semi-formed product in the molds 7 and 8 into a circular shape, and the center hole forming mechanism 20. The hydraulic extrusion 22 is driven when the mold is opened, and the cut pieces cut by the hydraulic punch 21 are ejected out of the molds 7 and 8.

The molded product having the center hole is taken out of the moving mold 8 by a suction cup member (not shown).

The mold clamping ram 4 during normal operation moves forward and backward together with the guide plate 15 in which the guide hole 15a is inserted in the guide pin 14 to prevent rotation through the guide plate 15 and also to prevent mold clamping. Bushings 9 and 9 mounted in the cylinder 2
At the same time, its parallelism is maintained with high accuracy.

As described above, in the mold clamping device 1, the center hole forming mechanism 20 is incorporated in the mold clamping ram 4, and the mold closing, the mold clamping and the mold opening are directly performed by the mold clamping cylinder 2 without using the moving die plate. As a result, not only is the moving die plate conventionally required unnecessary, there is no need to secure a moving space for the moving die plate within the entire length of the apparatus, and the pressure oil pipe 23 to the center hole forming mechanism 20 is provided. Since 24, 25, and 26 are led out from the rear portion 4b of the mold clamping ram 4 without projecting to the outside of the side portion of the cylinder block 3, it is not necessary to secure a piping installation space in the width direction of the device. .

Therefore, in the mold clamping device 1, the number of parts can be reduced, and at the same time, the overall size of the device and the space saving in the width direction can be reduced.

[0033]

As described above in detail, the present invention has the following effects.

That is, according to the first aspect of the present invention,
(1) The mold closing, mold clamping, and mold opening are performed directly by the mold clamping cylinder without passing through the movable die plate. Therefore, not only the moving die plate and the mold opening / closing cylinder are not required, but also the mold is moved within the entire length of the apparatus. It is not necessary to take in the moving space of the die plate, and (2) the pressure oil pipe to the center hole forming mechanism does not protrude outside the side of the mold clamping cylinder, but from the rear of the mold clamping ram to the outside. Since it is derived, it is possible to reduce the number of parts by eliminating the need for piping installation space in the width direction of the device, and to reduce the overall size of the device including space saving in the overall length and width direction of the device. It is possible to provide a mold clamping device for disk molding that enables the above.

According to the second aspect of the present invention, since the mold clamping ram is prevented from rotating and the parallelism is maintained through the guide plate, the molding accuracy in the disk molding is maintained.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a partial cross section of a disk molding mold clamping device as an embodiment of the present invention.

FIG. 2 is a side sectional view of an essential part of the disk-molding clamping device of FIG.

FIG. 3 is a plan sectional view of a main part of FIG.

4 is a view as viewed in the direction of the arrow Z in FIG. 2;

[Explanation of symbols]

 1 Clamping device for disc molding 2 Clamping cylinder 4 Clamping ram 4a Front part (of mold clamping ram) 4b Rear part (of mold clamping ram) 5 Fixed die plate 6 Tie bar 7 Fixed mold 8 Moving mold 13 Guide mechanism 20 Center hole forming mechanism 23, 24, 25, 26 Pressure oil piping

Claims (2)

[Claims] 1. A mold clamping device for disk molding, wherein a mold clamping cylinder and a fixed die plate are connected via a tie bar, and tension is applied to the tie bar by the mold clamping cylinder to perform mold clamping. A movable die, which is clamped to a fixed die held by a die plate, is held in the front part of the die clamping ram of the die clamping cylinder, and a center hole forming mechanism of the disc is installed in the die clamping ram. A disk-molding mold clamping device, wherein a pressure oil pipe, which is provided and communicates with the molding mechanism, is provided so as to extend outward from a rear portion of the mold clamping ram. 2. The mold clamping device for disk molding according to claim 1, wherein the mold clamping ram is attached while being prevented from rotation by a guide mechanism that guides axial movement. Mold clamping device.