JPH04361016A - Molding die for plastic optical part - Google Patents

Abstract

PURPOSE:To obtain a sufficient cooling time, and to improve accuracy and shorten a molding cycle by internally providing a mechanism conducting the mold clamping of a cavity unit in the cavity unit, installing the moving mechanism of the cavity unit and alternately conducting molding by a plurality of the cavity units. CONSTITUTION:A sliding plate 8 is mounted slidably to a sliding groove 7 formed to a moving side template 2. Two cavity units 9, 10 are placed on the sliding plate 8. A hydraulic cylinder 19 mold-clamping the cavity units 9, 10 is internally provided in the cavity units 9, 10. The cavity units 9, 10 are moved alternately by a unit moving cylinder 6, and injection molding is conducted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding plastic lenses etc. which requires a long cooling time.

0002

2. Description of the Related Art Conventionally, the following inventions have been disclosed as methods and devices for ensuring the precision of molded products.

For example, in the invention described in JP-A No. 64-36421, detachable unit molds are arranged on the fixed mold plate and the movable mold plate, respectively, and the respective unit molds are connected and integrated after mold clamping and injection. A connecting member is attached to the mold, and the runner in the mold is blocked by the connecting member, and the respective unit molds are connected and integrated.

[0004] Then, the integrated unit mold is taken out from between the mold plates and cooled outside the molding machine. An invention has been proposed in which another unit mold is attached to the mold plate during this cooling and the same cycle is repeated, thereby shortening the molding time while allowing sufficient cooling time for each unit mold.

[0005]

[Problems to be Solved by the Invention] However, when attempting to automate the invention described in Japanese Patent Application Laid-open No. 64-36421, it is necessary to use a large-scale robot or the like to remove the unit from the template and attach another unit. Requires equipment.

[0006] Another disadvantage is that a device for taking out the molded product from the unit mold is required.

[0007] Therefore, the present invention was developed in view of the drawbacks of the prior art, and it is possible to shorten the molding cycle while ensuring the precision of the molded product, and to achieve automation without the need for large-scale equipment. The purpose of the present invention is to provide a mold for molding plastic optical components that can be used to produce plastic optical components.

[0008]

[Means for Solving the Problems] The present invention provides a mold for molding plastic optical components in which heated and melted plastic is injected into a lens molding cavity, which includes a movable unit that can be opened and closed, and a fixed unit. A driving device for opening and closing is installed inside the cavity unit, and the cavity unit is arranged on a movable mold plate so as to be movable in a direction perpendicular to the mold opening and closing direction.

[0009]

[Operation] In the present invention, the cavity unit is provided with an opening/closing drive device and is configured to be movable.
It can be automated without the need for large-scale equipment such as robots.

0010

[Embodiment 1] Figures 1 to 11 show this embodiment, in which Figure 1 is a plan view of the mold attachment mechanism of a molding machine, Figure 2 is a partial perspective view of the mold attachment mechanism, and Figures 3 and 4. is an enlarged plan view of the cavity unit, and FIGS. 5 to 11 are process drawings.

Reference numeral 1 denotes a mold mounting mechanism section of a molding machine, and this mold mounting mechanism section 1 is composed of a movable mold plate 2 and a fixed mold plate 3.

The left side of the movable template 2 is the movable platen 4.
The movable platen 4 is fixed to a mold clamping mechanism 5 of the molding machine.

A unit movable cylinder 6 is attached to the upper surface of the movable template 2, and a sliding groove 7 is provided on the right side of the movable template 2.
A slide plate 8 is slidably provided in the slide groove 7.

Two cavity units 9 and 10 are placed on the slide plate 8, and the unit movable cylinder 6
Thus, the two cavity units 9 and 10 are configured to move together in a direction perpendicular to the mold opening direction (vertical direction in the figure).

The right side of the fixed side template 3 is the fixed side platen 1.
It is fixed at 1. The left side surface of the stationary mold plate 3 has three recesses 12 and 1 for receiving the cavity units 9 and 10.
3, 14 are formed, and a taper is formed on the side surface of each recess 12, 13, 14 so that the cavity units 9, 10 can be positioned.

Furthermore, the recess 12 and the recess 14 are similar to the recess 13.
The recesses are formed deeper than those in the molding machine, and when the molding machine performs mold clamping, the cavity units located at the positions of the recesses 12 and 14 are not clamped by the molding machine.

Furthermore, an injection nozzle 15 is in contact with the cavity unit 9 located in the recess 13 .

The cavity units 9 and (10) are composed of a movable unit 16 and a fixed unit 17.

A total of four hydraulic cylinders 18 are mounted inside the movable unit 16 at each of the four corners, and are connected to an external hydraulic pump (not shown) via a hydraulic hose 19.

The arm 20 of the hydraulic cylinder 18 passes through each of the mold plates 22 and 23 forming the cavity 21 to form a stop bolt 24 within the stationary unit 17.
By operating the hydraulic cylinder 18, the mold clamping force can be self-maintained and the mold opening of the cavity units 9, (10) can be performed to take out the molded product.
(See Figures 3 and 4).

A sprue 25 through which the melted resin passes is formed in the fixed unit 17, and the sprue 25 connects to the cavity 21 formed by the template 22 of the movable unit 16 and the template 23 of the fixed unit 17. It leads to

In the molding die constructed as described above, after the cavity unit 9 is clamped by the mold clamping mechanism 5 of the molding machine, melted resin is injected from the injection nozzle 15 into the cavity 21 through the sprue 25. Ru.

Then, in the next pressure holding process, the resin pressure inside the cavity 21 is reduced by the mold clamping mechanism 5 and the injection nozzle 1 of the molding machine.
It is held by a screw (not shown) in 5.

After sealing the gate, at a stage when the pressure of the resin has decreased, the hydraulic cylinder 18 is driven to clamp the cavity unit 9 (see FIG. 5).

When the mold clamping mechanism 5 moves back, the movable unit 16 does not move away because it is fixed to the movable mold plate 2, but the fixed unit 17 does not move away because it is not fixed to the fixed mold plate 3. Move away from template 3. At this time, the cavity unit 9 moves back together with the movable mold plate 2 as an integrated unit while maintaining a mold clamping force that is strong against the pressure inside the resin by the hydraulic cylinder 18 (see FIG. 6).

Next, the cavity units 9 and 10 move along the sliding groove 7 formed in the movable mold plate 2 in a direction perpendicular to the mold clamping direction, and the cavity units 9 and 10 move in the recess 12 of the fixed mold plate 3. However, the cavity unit 10 is placed in the recess 13.
(see FIG. 7).

Next, a mold closing operation is performed by the mold clamping mechanism 5,
When the mold is closed, the operation of the hydraulic cylinder 18 of the cavity unit 10 is stopped to release the self-retention of the mold clamping force. Then, in reverse, the hydraulic cylinder 18 is driven to open the cavity unit 10 (see FIG. 8).

In line with this operation, the mold clamping mechanism 5 is moved backward, the movable side unit 16 and the fixed side unit 17 of the cavity unit 10 are opened, and the molded product 26 that has been sufficiently cooled inside the cavity unit 10 is taken out. conduct. The molded product can be removed using a commonly used molded product removal device (see FIG. 9).

After taking out the molded product, the mold is clamped by the mold clamping mechanism 5. At this time, the fixed side unit 17 is accurately aligned by the tapered portion formed on the side surface of the recess 13 of the fixed side template 3. With the cavity unit 10 clamped, the melted resin from the injection nozzle 15 flows into the sprue 25.
is injected into the cavity 21, and molding of the cavity unit 10 is started.

After the gate is sealed, as in the case of the cavity unit 9, when the resin pressure has decreased, the hydraulic cylinder 18 is driven to clamp the cavity unit 10 (see FIG. 10).

Hereinafter, the same process as for the cavity unit 9 is performed for the cavity unit 10 as well. Then, the movable side unit 16 and fixed side unit 17 of the cavity unit 9 are opened, the molded product 26 that has been sufficiently cooled inside the cavity unit 9 is taken out, and the molded product 26 is removed from the cavity unit 9.
One cycle of is completed (see FIG. 11). After this, the mold is clamped again and continuous molding is performed.

[0032] According to this embodiment, the molding method improves the precision of the molded product by self-maintaining the mold clamping force during cooling, and also allows other cavity units to be taken out and injected during the long cooling process. As a result, the molding cycle can be shortened.

[0033] Furthermore, since the cavity unit is replaced by moving it along the sliding groove on the molding plate, and there is no need to remove the cavity unit from the molding machine, there is no need for a large-scale device for replacing the cavity unit. Instead, a small, low-output device is sufficient. Furthermore, the movement of the cavity unit is linear and simple, making it suitable for automation.

[0034]Furthermore, when taking out the molded product, the same condition as in taking out the molded product of normal molding is realized, so that a normal molded product taking out device can be used as is.

[0035]

[Example 2] Figures 12 to 14 show this example.
and FIG. 13 is an enlarged plan view of the cavity unit, FIG.
4 is a plan view of the mold attachment mechanism of the molding machine.

This embodiment differs in that a motor is used instead of the hydraulic cylinders 18 of the cavity units 9 and 10 in the first embodiment, and the other components are the same. are given the same number and their explanation will be omitted.

Reference numeral 31 designates a cavity unit, and a total of four motors 33 are disposed inside the movable unit 32 of the cavity unit 31 at each of the four corners, and are connected to an external controller (not shown). A pinion 34 is formed on the rotating shaft of the motor 33.
meshes with the rack 35.

FIG. 14 shows the state in which the cavity units 31a and 31b are attached to the mold attachment mechanism of the molding machine, and the cavity 36a of the cavity unit 31a and the cavity 36b of the cavity unit 31b have irregular shapes.

In the molding die constructed as described above, after the injection process and the pressure holding process, the motor 33 is driven when the resin pressure has decreased, and the cavity units 31a and 31b are moved through the pinion 34 and the rack 35. Self-maintains mold clamping force. When taking out the molded product, the motor 33 is driven to open the cavity units 31a and 31b.

Furthermore, by applying two conditions alternately on the molding machine side, different molded products are molded in the irregularly shaped cavities 36a and 36b.

According to this embodiment, the motor 33 has both the function of self-maintaining the mold clamping force and the function of opening the mold of the cavity unit when taking out the molded product. By using a motor instead of hydraulic pressure, it is possible to maintain a clean condition without oil leakage, and it is suitable for automation because it is directly controlled by electricity.

[0042] Also, since the cavity shapes are different,
A single molding machine can alternately mold lenses of irregular shapes.

[0043]

As explained above, according to the mold for molding plastic optical parts according to the present invention, a mechanism for clamping the cavity unit is provided in the cavity unit,
In addition, by providing a moving mechanism for the cavity units and performing molding alternately using a plurality of cavity units, sufficient cooling time can be obtained, accuracy can be improved, and the molding cycle can be shortened.

[0044] Furthermore, since the cavity unit is replaced by moving it along the sliding groove on the molding plate, and there is no need to remove the cavity unit from the molding machine, there is no need for a large-scale device for replacing the cavity unit. Instead, a small, low-output device is sufficient. Furthermore, the movement of the cavity unit is linear and simple, making it suitable for automation.

Furthermore, when taking out the molded product, the same condition as in taking out the molded product in normal molding is realized, so that a normal molded product taking out device can be used as is.

[Brief explanation of drawings]

FIG. 1 is a plan view of a mold attachment mechanism section of Example 1.

FIG. 2 is a partial perspective view of the mold attachment mechanism of Example 1.

FIG. 3 is an enlarged plan view of the cavity unit of Example 1.

FIG. 4 is an enlarged plan view of the cavity unit of Example 1.

FIG. 5 is a process diagram of Example 1.

FIG. 6 is a process diagram of Example 1.

FIG. 7 is a process diagram of Example 1.

FIG. 8 is a process diagram of Example 1.

FIG. 9 is a process diagram of Example 1.

FIG. 10 is a process diagram of Example 1.

FIG. 11 is a process diagram of Example 1.

12 is an enlarged plan view of the cavity unit of Example 2. FIG.

13 is an enlarged plan view of the cavity unit of Example 2. FIG.

FIG. 14 is a plan view of the mold attachment mechanism of Example 2.

[Explanation of symbols] 1 Mold mounting mechanism part 2 Movable side template 3 Fixed side template 4 Movable platen 5 Mold clamping mechanism 6 Movable cylinder 7 Sliding groove 8 Slide plate 9,10 Cavity unit 11 Fixed side platen 12, 13, 14 recess 15 Injection nozzle 16 Movable side unit 17 Fixed side unit 18 Hydraulic cylinder 21 Cavity 31 Cavity unit 32 Movable side unit 33 Motor 34 Pinion 35 rack 36a 36b Cavity

Claims (1)

[Claims] Claim 1: In a mold for molding plastic optical components in which heated and melted plastic is injected into a lens molding cavity, a cavity unit consisting of a movable side unit and a fixed side unit that can be opened and closed is provided with an opening/closing drive. A mold for molding plastic optical components, characterized in that a device is installed therein, and a cavity unit is arranged on a movable mold plate so as to be movable in a direction orthogonal to the mold opening/closing direction.