JP3483808B2 - Disc mold air pump - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION In a mold for molding a disc substrate such as a CD or a DVD, the disc substrate is released from the cavity surface of the die, or the released disc substrate is attracted to the die. The present invention relates to an air pump that generates compressed air.

[0002]

2. Description of the Related Art FIG. 1 is a partial cross-sectional view of a mold for molding a disk substrate. The mold 1 is a fixed mold 2.
And movable mold 3. The fixed mold 2 and the movable mold 3 are attached to a mold clamping device (not shown) so as to be close to and away from each other, and a cavity 22 is formed when the two molds come into contact with each other and are matched with each other. The fixed mold 2 includes a fixed outer peripheral ring 4 fixed to the outer periphery of the fixed mold plate 5, a fixed mirror plate 6 fixed to the center of the fixed mold plate 5, and a central opening of the fixed mold plate 5 and the fixed mirror plate 6. The mess cutter 7 is inserted into the messcutter 7, and the sprue bush 8 is inserted into the inner hole of the messcutter 7. The movable mold 3 includes a movable outer peripheral ring 9 that comes into contact with the fixed outer peripheral ring 4, a movable mold plate 10 that covers the movable outer peripheral ring 9, a movable mirror surface plate 13 fixed to the center of the movable mold plate 10, and a movable mirror. The outer peripheral stamper retainer 11 externally mounted on the face plate 13, the spacer 15 fixed to the central opening of the movable mold plate 10, the inner peripheral stamper retainer 14 externally mounted on the spacer 15, the ejector 16 installed in the spacer 15, and the ejector 16 Interior Oscar 17
And a stamper 12 arranged on the surface of the movable mirror surface plate 13 and held by an outer peripheral stamper retainer 11 and an inner peripheral stamper retainer 14.

When the fixed outer peripheral ring 4 and the movable outer peripheral ring 9 are brought into contact with each other to align the fixed mold 2 and the movable mold 3,
The fixed mirror surface plate 6, the mescutter 7, the outer peripheral stamper retainer 11, the stamper 12, the inner peripheral stamper retainer 14, the spacer 15, the ejector 16, the male cutter 17, and the cavity 22.
Is formed. At this time, the molten resin injected from the injection device (not shown) is filled in the cavity 22 through the inner hole of the sprue bush 8. The molten resin in the cavity 22 is cooled and solidified into the shape of the disk substrate, and the male cutter 17 is advanced at a predetermined timing to form a central opening in the disk molded product in the process. Thereafter, a first air passage 18 communicating with an annular groove formed by the inner periphery of the central opening of the fixed mirror plate 6 and the outer periphery of the mescutter 7, and a second air passage communicating with the gap between the outer periphery stamper retainer 11 and the surface of the stamper 12. 19, a third air passage 20 communicating with an annular groove formed by the inner peripheral surface of the inner peripheral stamper retainer 14 and the outer peripheral surface of the spacer 15 is supplied with air of a predetermined pressure at a predetermined time, respectively, to form a disk molded product. Is released from the surfaces of the fixed mirror plate 6 and the stamper 12. At this time, in the prior art, from the air pressure source accumulated by the air compressor to the throttle valve,
Air whose flow rate and pressure have been adjusted is supplied to the air passage through a flow rate adjusting valve or a pressure reducing valve. A vacuum pump (not shown) is connected to the fourth air passage 21 to adsorb the outer peripheral back surface of the stamper 12 to hold the stamper 12 on the surface of the movable mirror plate 13.

[0004]

By the way, in order to release a thin disk molded product, particularly a DVD disk molded product, without causing a defective appearance of stains and smears and warpage, the air pressure is set to an extremely low pressure. It may be necessary to slow the flow rate. In order to do this by the above-mentioned conventional method, it is necessary to make the throttle valve a minute opening degree, and the lower the pressure, the more unstable the pressure and flow velocity, and the above-mentioned defects occur in the molded product.

Further, although the amount of air supplied to each air passage is constant, it may be effective to change the amount of air supplied over time depending on the mold and molding conditions. In order to realize it by the conventional technique, a plurality of throttle valves and pressure reducing valves are switched by a switching valve, but shock and discontinuity phenomenon occur at the time of switching, and it is also unstable.

[0006]

Therefore, a cylinder in which a piston is airtightly inserted, a drive unit for driving the piston, and a setting unit for instructing a moving amount and a moving speed of the driving unit are provided.
And a control unit that controls the drive unit according to the signal from the setting unit, and further reverses the air from the air source to the pipe line connecting the air passage of the mold and the cylinder so that the air from the air source is in the forward direction. The stop valve was connected.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail with reference to FIG. The mold is the same as the mold 1 described in detail in the section of the related art, and therefore the description thereof is omitted in this section. Further, the pump 39 according to the present invention is connected to the first air passage 18, the second air passage 19 and the third air passage 20 of the mold 1, but since they are all the same, the third air passage 20 Only the connected pump 39 is shown and the others are omitted.

The main components of the pump 39 are a cylinder 23 in which a piston 24 is pneumatically fitted, a motor 31 for driving the piston 24, a setting section 37 for setting the rotation amount and speed of the motor 31, and a The control unit 38 controls the motor according to the signal from the setting unit 37.

The cylinder 23 is in the shape of a cylindrical container and has a port 34 on one end surface and a port 35 on the other end surface. The piston 24 is a disk-shaped member which is fitted on the inner surface of the cylinder 23 so as to be air-tightly and smoothly slidable without leaking air. One end of a rod 25 is fixed to the piston 24, and the rod 25 slidably penetrates the end face of the cylinder 23 on the port 34 side, and the piston 24 can be moved from the outside of the cylinder 23. A tie bar 28 is fixed to the other end of the rod 25, and ball screws 26, 26 are fixed to both ends of the tie bar 28. Ball screw nuts 27, 27 engaged with the cylinder 23 at a fixed position are screwed into the ball screws 26, 26, and the ball screw nut 2
The belts 7 and 27 are driven to rotate. The belt 30 is driven by a motor 31 via a pulley 29. The motor 31, the pulley 29, the belt 30, the ball screw nut 27, the ball screw 26, the tie bar 28, and the rod 25 constitute a drive unit. The drive unit has various embodiments other than the above. For example, ball screw 26
A rack and a pinion may be used instead of the ball screw nut 27. Further, the rod 25 is not fixed to the piston 24, the cylinder 23 is made of a non-magnetic material, the piston 24 is made of a ferromagnetic material or a magnet, and an annular magnet loosely penetrating the cylinder 23 is linearly driven by a motor to bring the piston 24 into non-contact. It can also be driven.

The motor 31 may be an induction motor, but a servo motor is preferable if a rising speed of rotation and high control accuracy are required. If the motor 31 is a servo motor, a position detector 32 is attached, and the rotation angle of the servo motor, that is, the movement amount and speed of the piston 24 can be detected, and the air amount can be controlled with extremely high accuracy.

The setting unit 37 sets the amount of air supplied to the air passage. When the setting unit 37 receives a signal for starting air blowing (positive pressure) or air suction (negative pressure) from the control device of the injection molding machine, the setting unit 37 sets the motor based on the air operation time and the operation pattern set in advance in the setting unit 37. The rotational speed of 31 and its switching time point are calculated and obtained, and a control signal is output to the control unit 38. The controller 38 controls the motor 31 so that the motor 31 rotates according to the control signal. If the motor 31 is a servo motor, the control unit 38 obtains a speed signal from the position signal of the position detector 32 and performs feedback control so that the rotation of the servo motor matches the control signal.

FIG. 1 shows a state in which the pump 39 is provided in the third air passage 20, and the operation in this case will be described. When the control unit of the injection molding machine issues an air blowing start signal to the setting unit 37 at an appropriate timing of the cooling and solidifying process in which the molten resin is injected and filled in the cavity 22, a predetermined air blowing process is started and the disk molded product is It is released from the vicinity of the central opening.
Slightly before and after this, air is also supplied to the second air passage 19 from another pump, so that the disk molded product is released from the stamper 12 over the inner and outer circumferences. Also, since air is supplied to the first air passage 18 from another pump at an appropriate time, the disk molded product has cavity 22 on both sides.
It is released from the surface. After that, the movable mold 3 becomes the fixed mold 2
Although the disk molding is separated from the surface of the stamper 12, it cannot hold the disk molding as the movable mold 3 moves, and the protruding male cutter 1
The central opening is only slightly engaged with 7. Therefore,
The pump 39 is operated under negative pressure to adsorb the disk molded product.

The piston 24 was moved forward (to the left in the drawing) to generate positive pressure air for release, but after the disk molded product was released from the mold, the motor 31 was rotated in reverse and the piston 24 was moved backward (to the right). Generates negative pressure air. At this time, the check valve 3
Atmosphere or separately prepared dry air is sucked from the air source 33 through 6, but if the elastic force (cracking pressure) of the spring that elastically urges the plunger of the check valve 36 is set to an appropriate level, a negative force corresponding to that force is obtained. Pressure is generated.

[0014]

As a result of the above-mentioned configuration of the present invention, not only the relatively low pressure air pressure required when releasing a thin-walled disk molded product is generated very stably, but also the flow rate of the air pressure is reduced. Since smooth and accurate ejection is performed according to a predetermined program, it is possible to prevent defects such as stains and smears on the disk molded product and warpage, and continuously mold good products.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a pump according to the present invention, a block diagram, and a partial cross-sectional view of a mold to which the pump is applied.

[Explanation of symbols]

1 ……… Mold 2 ……… Fixed mold 3 ……… Movable mold 4 ………… Fixed outer ring 5 ……… Fixed template 6 ……… Fixed mirror plate 7 ………… Mescatta 8 ……… Sprue Bush 9 ……… Movable outer ring 10 ...... Movable template 11 …… Perimeter stamper retainer 12 …… Stamper 13 ... Movable mirror plate 14 ... Inner circumference stamper presser 15 …… Spacer 16 …… Ejector 17 …… Oscatta 18 ...... First air passage 19 ...... Second air passage 20: Third air passage 21 ...... 4th air passage 22 …… Cavity 23 …… Cylinder 24 ...... Piston 25 …… Rod 26 ... Ball screw 27 …… Ball screw nut 28 ...... Taiba 29 …… Pulley 30 …… Belt 31 …… Motor 32 ...... Position detector 33 …… Air source 34, 35 ...... Port 36 ...... Check valve 37 …… Setting section 38 ... Control unit 39 ... Pump

Claims (2)

(57) [Claims] 1. An air pump for releasing a disk substrate formed by a disk die from a cavity surface or generating positive and negative compressed air for adsorbing the released disk substrate, wherein a piston is airtightly inserted. A cylinder, a drive unit that drives the piston, a setting unit that commands a movement amount and a moving speed of the drive unit, and a control unit that controls the drive unit according to a signal from the setting unit, Air pump for disk mold. 2. The check valve according to claim 1, wherein a check valve is arranged in a pipe line connecting the air passage of the mold and the cylinder so that air from the air source is in a forward direction. Disk mold air pump.