JP2823905B2 - Molding method and mold for optical reflection mirror - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a molding method and a molding die for an optical reflection mirror molded from plastic.

[Prior art] A conventional molding method using a plastic material involves filling a mold with a plastic material melted and softened at a high pressure, inverting the mold formation with the pressure, and molding a reflective mirror having a plane with high accuracy. I was Further, as a molding die different from the above, there is a molding die described in Japanese Utility Model Laid-Open No. 62-102608.

The technology of the molding die described in this publication is based on the following technology. When an oil seal is arranged on a lower die side in a molding cavity formed between an upper die and a lower die, a sliding surface of an oil seal to be manufactured is used. This is a technique in which small projections formed by metal spraying are additionally formed on the surface of a lower mold corresponding to the above using a high-temperature gas.

[Problem to be Solved by the Invention] In the above-mentioned conventional technology, when molding is performed by the former method,
Good flatness can be obtained in the mold, but when the molded product is released from the mold, deformation of the molded product occurs due to the internal stress generated in the mold at the time of formation, which is inappropriate as an optical reflection mirror. The surface was frequently distorted. For this reason, the yield in molding is poor, and the cost must be increased. Also, in the technique disclosed in the latter publication, that is, a molding die for oil seals, fine projections are provided by metal spraying on the surface of a metal mold. However, these fine projections increase the biting force on the mold of the molded product. However, there has been a problem that deformation such as distortion occurs in the molded product.

The present invention was created in order to solve the above-described problems, performs molding without applying pressure that causes deformation of a molded product, and accurately and accurately forms a required plane for an optical reflection mirror and the like. An object of the present invention is to provide a molding method and a molding die for a plastic optical reflecting mirror which can be molded efficiently at low cost.

Means and Action for Solving the Problems According to the present invention, in a molding die of an optical reflection mirror having a cavity for molding an optical reflection mirror made of plastic, a desired mold for molding a part of the cavity is provided. A first member having a molding surface, a second member having a desired molding surface for forming a part of the cavity facing the molding surface of the first member, and the first member or the Ultrasonic vibration generating means for applying ultrasonic vibration to the molding surface of the second member.

The molding surface facing the molding surface to which ultrasonic vibration is applied by the ultrasonic vibration generating means is formed as a desired surface, that is, a mirror surface for an optical reflecting mirror.

Further, the present invention provides a method for forming an optical reflecting mirror made of plastic as a first material having a desired forming surface.
Forming a part of a cavity with a member having a molding surface opposite to the molding surface of the first member; filling a plastic material into the cavity; Applying ultrasonic vibration to the molding surface of the member or the second member, and transferring the shape of the molding surface on the side not applying ultrasonic vibration to a plastic material.

According to the molding die and the molding method, since a part of the plastic material filled in the cavity is ultrasonically vibrated, shrinkage of the filled plastic material occurs based on the molding surface that does not ultrasonically vibrate. The molding surface, that is, the desired surface is transferred to the plastic material with high precision.

Example An example of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a side surface of a main part obtained by cutting a molding die of an optical reflection mirror embodying the present invention in half.

FIG. 2 is an enlarged cross-sectional view showing a main part of a molding portion of the molding die shown in FIG.

As shown in FIG. 1, a fixed die plate 8 is integrally mounted on the lower end surface of the fixed mounting plate 5 having a hole formed at the center position. On the inner periphery of the fixed-side mold plate 8, a flange-shaped flange portion projecting to the outer periphery of the upper end portion is formed so as to match the step formed on the upper end side of the inner periphery of the fixed-side mold plate 8. A cylindrical fixed side sleeve 6 is integrally mounted. Further, a cylindrical fixed side piece 7 (first member) is integrally inserted and mounted on the inner periphery of the fixed side sleeve 6. That is, the upper end surface of each of the fixed-side mounting plates 5 and the inner peripheral surfaces thereof are closely mounted to form a fixed-side upper die.

A movable mold plate 9 having the same size as the outer diameter of the fixed mold plate 8 of the fixed upper mold is integrally mounted on the receiving plate 16. A cylindrical movable sleeve 10 having a flange-shaped flange formed on the inner periphery of the movable mold plate 9 so as to coincide with a step formed at the lower end of the inner periphery of the movable mold plate 9. Are integrally mounted.

A movable movable piece 11 (second member) having a columnar shape is fitted and mounted on the inner periphery of the movable sleeve 10 so as to be slidable in a vertical direction (axial direction).

The movable side piece 11 has an upper end surface formed on the movable side sleeve.
It is formed shorter than the upper end surface of each of the movable mold plate 10 and the movable mold plate 9. That is, a space (cavity) 12 for forming a part to be molded is provided between the lower end surface of the fixed side piece 7 of the fixed upper die and the upper end surface of the movable side piece 11. The upper end surface 18 of the movable side piece 11 of the cavity 12 is formed as a mirror surface to form an optical reflection surface.

A boundary end (parting line 19) between the movable side plate 9 and the fixed side template 8 on the receiving plate 16, that is, a lower end face of each of the fixed side sleeve 6 and the fixed side template 8, and a movable sleeve As shown in the figure, a gate 4 and a runner 3 for supplying a plastic material into the cavity 12 are connected in series to a part of the upper end surface of the movable mold plate 10 and the movable mold plate 9 as shown in the figure. It is formed continuously.

Further, a funnel-shaped spool bush 1 is mounted on the fixed-side mounting plate 5 and the fixed-side mold plate 8, and the inside of the shaft core, that is, the tip opening of the spool 2 is configured to communicate with one end of the runner 3. When a plastic material is put into the spool bush 1, it is injected into the runner 3 through the spool 2, flows into the cavity 12 through the gate 4, and is filled.

The center position of the lower end surface of the movable piece 11 constituting the movable die, the lower end surface position of the tip end side (gate 4 side) of the runner 3, the tip end of the spool 2, that is, the tip end in the axial direction of the spool 2. A hole is formed in each of the receiving plate 16, the movable mold plate 9, and the movable sleeve 10, which are disposed at the lower positions, and the core pin 15 and the runner projecting pin 14 are formed in the holes.
And a spool protruding pin 13 are provided so as to be slidably fitted to each other, and a protruding pin (not provided) for releasing the molded component after being molded in the cavity 12 from the lower mold (movable mold). (Illustration), so as to operate synchronously.

As shown in the figure, a hole is formed in the fixed-side mounting plate 5 corresponding to the center position of the upper end surface of the fixed-side piece 7 and the lower end is inserted into the hole to be connected to the upper end surface of the fixed-side piece 7. , An acoustic vibration generator 21 (ultrasonic vibration generator) is provided. The ultrasonic vibration generator 21 is connected to a control unit 22. The control unit 22 is connected to a molding machine controller 23.
That is, the control unit 22 receives a signal generated by the molding machine controller 23 and operates the ultrasonic vibration generator 21 to apply ultrasonic vibration to the fixed-side piece 7.

 Next, a molding method using the molding die having the above configuration will be described.

First, as shown in the figure, when a plastic material that has been melted and softened is injected and supplied from the spool bush 1 mounted on the fixed side mounting plate 5 and the fixed side template 8, the material is supplied to the spool 2 that is configured to communicate with the spool bush 1. Going down,
It flows into and passes through the runner 3 which is configured to communicate with the spool 2. Further, the cavity passes through the gate 4 from the tip of the runner 3.
It flows into 12 and is filled without applying pressure that causes molded articles.

When a signal is issued from the molding machine controller 23 following the completion of the filling of the plastic material in the cavity 12, the control unit 22 receives the signal and operates the ultrasonic vibration generator 21. That is, the fixed side piece 7
Will be subjected to ultrasonic vibration.

In this state, the plastic material filled in the cavity 12 starts to contract with cooling. At this time, the plastic material on the fixed side piece 7 contracts while the ultrasonic vibration is activated.

Further, the plastic material itself generates heat by the ultrasonic vibration, so that the lower end surface of the fixed side piece 7 is hardly cooled. For this reason, the shrinkage is based on the upper end surface 18 of the movable side piece 11, and the upper end surface (mirror surface) 18 of the movable side piece 11 is transferred to the part to be molded as it is.

After waiting for cooling in the cavity 12 in which the above-mentioned part has been molded, the upper die and the lower die are separated from the parting line 19. That is, the receiving plate is connected via a projecting pin (not shown).
A molded product in which the plane of the optical reflection mirror with higher precision is formed in the cavity 12 by the operation of the core pin 15, the runner projecting pin 14, and the spool projecting pin 13 which are slidably fitted in the respective holes formed in the hole 16. Is taken out.

In the above embodiment, the ultrasonic vibrator 21 and the like are mounted on the fixed piece 7 side. However, the present invention is not limited to this, and the ultrasonic vibrator 21 may be used in accordance with the required number of mirror surfaces of the part to be molded. It goes without saying that the vibration device may be connected and configured.

[Effects of the Invention] According to the molding die and the molding method, of the plurality of members forming the cavity, the member provided opposite to the portion having the desired surface of the molded component to be molded is provided with the ultrasonic vibration generating means. By applying the ultrasonic vibration, the effect that an optical reflecting mirror having a desired surface of high quality can be manufactured at low cost and with good productivity is great.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a side surface of a main part obtained by cutting a molding die of an optical reflection mirror embodying the present invention in half. FIG. 2 is an enlarged sectional view showing a main part of the molding die shown in FIG. 1; DESCRIPTION OF SYMBOLS 1 ... Spool bush 2 ... Spool 3 ... Runner 4 ... Gate 5 ... Fixed side mounting plate 6 ... Fixed side sleeve 7 ... Fixed side piece 8 ... Fixed side mold plate 9 ... Movable side mold plate 10 movable sleeve 11 movable piece 12 cavity 13 protruding spool pin 14 runner protruding pin 15 core pin 16 receiving plate 18 mirror surface 19 parting line 21 Ultrasonic vibrator generator 22 Controller unit 23 Molding machine controller

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Kenji Haga 2-43-2 Hatagaya, Shibuya-ku, Tokyo Inside O-Limpus Optical Industry Co., Ltd. (72) Inventor Kaoru Maeda 2-43-2 Hatagaya, Shibuya-ku, Tokyo Within Olympus Optical Industries, Ltd. (72) Inventor Makio Yamada 2-43-2, Hatagaya, Shibuya-ku, Tokyo Inside Olympus Optical Industries, Ltd. (56) References JP-A-58-134722 (JP, A) JP-A-62-135333 (JP, A) JP-A-58-20413 (JP, A) JP-A-1-182016 (JP, A) JP-A-2-47026 (JP, A) JP-A-2-137211 ( JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 45/00-45/84 B29C 33/00

Claims (2)

(57) [Claims] 1. A method for molding an optical reflection mirror made of plastic, comprising: a first member having a desired molding surface and a second member having a molding surface facing the molding surface of the first member. A step of molding a part of the cavity; a step of filling the cavity with a plastic material; and a side on which ultrasonic vibration is applied to the molding surface of the first member or the second member, and the ultrasonic vibration is not applied. Transferring the shape of the molding surface to a plastic material. 2. A molding die for an optical reflection mirror having a cavity for molding an optical reflection mirror made of plastic, comprising: a first member having a desired molding surface for forming a part of the cavity; A second member having a desired molding surface for forming a part of the cavity facing the molding surface of the first member; and an ultrasonic wave on the molding surface of the first member or the second member. A molding die for an optical reflection mirror, comprising: an ultrasonic vibration generating means for giving vibration.