JPH10180815A - Insert mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a molding having high quality appearance and heighten dimensional precision of the molding. SOLUTION: In this insert mold 2, an insert molding is conducted by housing a component 1 in a cavity A formed in cooperation with a first cavity 5 provided in a first mold 3 and a second cavity 8 provided in a second mold 4. In the first mold 3, a component pressing means 12 arranged opposite to one wall face 8a forming the second cavity 8 for pressing the component 1 to the wall face 8a of the second cavity 8 so as to hold the component 1 in the cavity A is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insert die and, more particularly, to an insert die used for insert-molding minute components.

[0002]

2. Description of the Related Art As shown in FIG. 4, an insert mold 100 of this kind, which has been generally used in the past, comprises an upper mold section 101 which moves up and down and a fixed lower mold section 102, and is internally provided. It has a cavity 103 for accommodating the component 1. Therefore, insert part 1 is inserted into cavity 103.
After loading (see FIG. 5), the upper mold part 101 and the lower mold part 10
2 and the cavity 1 through the runner 104.
The molten resin is supplied in 03. As a result, the component 1 and the molten resin are integrated, and a molded product S as shown in FIG.

[0003]

The conventional insert mold 100 has the following problems because it is configured as described above. That is, in the conventional insert mold 100, the cavity 103 is formed to have a size that can accommodate the component 1, and a desired clearance C is provided around the component 1. Without the clearance C, not only the part 1 cannot be loaded into the cavity 103, but also the part 1 is crushed by the pressure when the upper mold part 101 and the lower mold part 102 are clamped. Therefore, a desired clearance C is required between the component 1 and the cavity wall surface 103a. However, when the cavity 103 is filled with the molten resin, the clearance C formed so as to surround the
Will dance in the cavity 103, causing not only burrs on the molded product A but also a misalignment of the component 1.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and in particular, provides an insert mold for producing a molded product having a high-quality appearance and improving the dimensional accuracy of the molded product. The purpose is to:

[0005]

According to a first aspect of the present invention, there is provided an insert mold having a first cavity provided in a first mold and a second cavity provided in a second mold. In the insert mold for accommodating parts in the cavity formed by cooperation with the cavity part and performing insert molding, in the first mold part, one wall surface forming the second cavity part is provided. A component pressing means is provided which is opposed to the first cavity portion and presses the component against one wall surface of the second cavity portion to hold the component in the cavity.

In this insert mold, parts are loaded into the second cavity while the first mold and the second mold are opened, and then the mold is clamped. When the mold is clamped, the component is pressed against one wall surface of the second cavity portion by component pressing means arranged to face one wall surface of the second cavity portion. Thus, the component is
By pressing against one wall surface of the cavity part, the part is securely held in the cavity even when a clearance is generated around the part. Therefore, when the molten resin is filled in the cavity, the component does not dance in the cavity, burrs are not easily generated on the molded product, and the component does not shift in the cavity.

In this case, the component pressing means is provided in the first mold portion and is disposed in the guide hole extending in the pressing direction of the component, moves along the guide hole, and moves when the mold is closed. A movable member having a distal end surface that abuts against a pressing surface of the component at a position facing the cavity portion, and a spring member provided on the first mold portion and biasing the movable member toward the pressing surface of the component. It is preferable to have When such a configuration is adopted, the component presses the distal end surface of the movable member against the pressing surface of the component via the elastic force of the spring member. It is pressed against the wall. That is, at the position facing the second cavity portion, the tip end surface of the movable member abuts against the pressing surface of the component, so that when the component is pressed against one wall surface of the second cavity portion, the movable member is provided on the first mold portion. Along the provided guide hole, the movable member retreats against the spring force of the spring member,
It is held in the cavity by the movable member.
Therefore, when closing the mold, first, the front end surface of the movable member abuts against the pressing surface of the component, presses the component against one wall surface of the second cavity portion, and holds the first component while holding the component in the cavity.
The mold closing of the mold part and the second mold part is completed. By having such a configuration, the displacement of the component does not occur due to the clearance generated around the component, and at the time of mold clamping,
The first mold part does not collide with the component, and the component does not suffer from "scratch", "chip" or the like. Then, since the pressing surface of the component and the distal end surface of the movable member are in close contact with each other, no burr is generated on the pressing surface of the component.

[0008] The component pressing means has a tip end surface which is inserted into a through hole formed in the center of the movable member, is fixed to the first mold part, and forms a part of the first cavity part. It is preferable to further include a fixing member. That is, in a state where the fixed member is inserted into the through hole of the movable member, the fixed member is fixed to the first mold portion, so that the fixed member does not follow the movement of the movable member. Follow the movement of the mold part. And by making the front end surface of the fixing member a part of the first cavity portion,
The desired shape can be integrally formed with the component.

Further, the movable member is an elongated tubular sleeve member extending in the pressing direction of the component, and the spring member is
A disc spring disposed at a position for urging the head of the sleeve member, wherein the fixed member is inserted into the through hole of the movable member, extends in the pressing direction of the component, and is elongated and guides the movement of the sleeve member. It is a pin member.
It is preferable that a concave portion forming a shaft portion integrally formed with the cylindrical component is provided. When such a configuration is employed, even a fine cylindrical component that is likely to be displaced in the cavity can be used as an insert component.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an insert mold according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view showing an insert mold according to the present invention, and FIG. 2 is a sectional view showing a main part of the insert mold shown in FIG. The insert mold 2 shown in these drawings includes an upper mold part (first mold part) 3 forming a movable mold part and a lower mold part (second mold part) forming a fixed mold part. ) 4 and these are incorporated in an injection molding machine (not shown). The upper mold part 3 is driven vertically and has an upper cavity part (first cavity part) 5 which constitutes a part of the upper part of the cavity A, and the lower mold part 4
Is composed of a base 6 fixed on a predetermined mounting base, and a slide piece 7 which is divided and opened right and left on the upper surface of the base 6.

The lower mold part 4 includes a lower cavity part (a second cavity part) 8 forming a part of a lower side of the cavity A.
The base portion 6 is provided with a base side cavity portion 9 which forms a part of the lower side cavity portion 8. As shown in FIG. 3, the slide piece 7 is provided with a divided cavity portion 10 that constitutes a part of the lower cavity portion 8, and the slide piece 7 has a configuration in which the slide piece 7 is divided into right and left and opened and closed. . By utilizing such a slide piece 7, the circumferential direction of the cylindrical component 1 made of a magnetic material can be divided into divided cavity portions 10.
And the clearance C between the peripheral surface of the component 1 and the wall surface of the divided cavity portion 10 can be reduced as much as possible. Then, depending on the type of division of the slide piece 7, it becomes easy to load the component 1 (see FIG. 5) into the lower mold part 4 and to remove the molded product S (see FIG. 6) from the lower mold part 4.

This insert mold 1 is an injection mold for manufacturing a swing type rotor S as a molded product to be built in a motor such as a shutter of a camera. As shown in FIG. The child S includes a magnetic body 11 made of a magnetic material, and a resin portion 12 integrally formed with the magnetic body 11. The resin portion 12 includes shaft portions 23A and 23B protruding from the upper and lower ends of the cylindrical magnetic body 11, and an operating arm 24 protruding from the peripheral surface of the magnetic body 11 and driving an opening / closing lever of a shutter (not shown). , Shaft portion 23A, 2
3B and the operating arm 24 are integrated.

As shown in FIGS. 1 and 2, when performing insert molding with a resin, a magnetic material 11 in an unmagnetized state before becoming a magnet is provided in a lower cavity portion 8 of a lower mold portion 4. Is inserted. This part 1 is extremely small, about 4 mm in diameter and about 5 mm in length, and must be securely held in the lower cavity 8 during insert molding.

In view of this, the upper mold part 3 incorporates a part pressing means 12 for pressing the part 1 from above against a bottom wall surface 8a forming a part of the lower cavity part 8, and the part pressing means 12 includes And a cylindrical sleeve member 14 as a movable member that slides along a guide hole 13 that extends in the pressing direction (vertical direction) of the component 1. This sleeve member 1
Reference numeral 4 denotes a sleeve main body portion 14a having a diameter substantially equal to that of the guide hole 13 and having a diameter of about 5 mm.
And a head part 14b provided on the top of the head. The head portion 14b is accommodated in the extension portion 13a of the guide hole 13, and a disc spring 15 which is an example of a spring member is inserted between the upper wall surface of the extension portion 13a and the upper end surface of the head portion 14b. I have. In addition, the lower wall surface of the extension portion 13a and the head portion 14
b, a washer member 16 is disposed between the lower end surface and
The head 14 b is pressed against the washer member 16 by the urging force of the disc spring 15. By changing the thickness of the washer member 16, the height of the head portion 14b can be arbitrarily adjusted.

As shown in FIG. 2, the sleeve body 14a
Is located at a position facing the upper opening of the lower cavity portion 8 when the mold is closed, and faces the pressing surface (upper surface) 1a of the component 1. Therefore, due to the urging force of the disc spring 15, the tip surface 14c of the sleeve body 14a protrudes from the parting surface 17 of the upper mold portion 3 when the mold is opened (see a two-dot chain line). Face 14
c is pressed against the pressing surface 1 a of the component 1. That is, at the time of closing the mold, first, the front end surface 14c of the sleeve member 14 contacts the pressing surface (upper end surface) 1a of the component 1, and the contact surface (lower end surface) 1d of the component 1 The mold closing is completed while pressing the part 1 tightly against the wall surface 8a and holding the part 1 in the cavity A.

By performing such a mold closing, the displacement of the component 1 does not occur due to the clearance C generated between the wall surface of the lower cavity portion 8 and the peripheral surface of the component 1.
In addition, the upper mold part 3 does not collide with the part 1 during mold clamping,
There is no occurrence of "scratch" or "chip" in the component 1. Also, when the cavity A is filled with the molten resin, the component 1 does not dance in the cavity A, and it is difficult for the molded product S (see FIG. 6) to generate burrs. It is not triggered. When the mold clamping is completed, the distal end surface 14c of the sleeve member 14 comes into close contact with the pressing surface 1a of the component 1, so that the distal end surface 14c of the sleeve member 14 and the pressing surface 1a of the component 1 It is possible to prevent the occurrence of burrs at this portion without the molten resin entering.

As shown in FIGS. 1 and 2, the component pressing means 12 is provided with a through hole 14 formed in the center of the sleeve member 14.
It has an elongated pin member 18 having a diameter of about 3 mm as a fixing member inserted into the part d. By fixing the upper end of the pin member 18 to the upper mold part 3, the pin member 18
Instead of following the movement of the sleeve member 14 and following the movement of the upper mold part 3, the sleeve member 14
Move up and down to guide with. In addition, the lower end of the pin member 18 has a tip surface 18 which is a part of the upper cavity 5.
a is formed. A concave portion 19 is provided in the distal end surface 18a, and the concave portion 19 forms a shaft portion 23A (see FIG. 6) protruding from the pressing surface 1a of the component 1.

The recess 19 is formed in the shaft hole 1b of the component 1 (FIG. 5).
The upper portion of the shaft portion 23A is arranged so as to close the upper opening of the shaft portion 23A.
(See FIG. 6) is formed. The outer shape of the collar 23a is
It is regulated by the diameter of the tip of the through hole 14d of the sleeve member 14. The distal end surface 14c of the sleeve member 14 projects so as to surround the periphery of the concave portion 19.
Therefore, at the time of injection molding, the front end surface 14c of the sleeve member 14 is pressed against the pressing surface (upper end surface) 1a of the component 1, so that the molten resin does not enter this portion.
As a result, no burr is generated in the flange portion 23a, and the shaft portion 23A without burrs can be created. A concave portion 25 is formed on the bottom wall surface 8a of the lower mold portion 4 so as to close the lower opening of the shaft hole 1b of the component 1, and a bottom wall surface 8a is formed so as to surround the periphery of the concave portion 25. I have. Accordingly, the contact surface (lower end surface) 1d of the component 1 is pressed against the bottom wall surface 8a, so that the molten resin does not enter this portion, and the occurrence of burrs at this portion can be prevented.
A shaft portion 23B without burrs can be created.

Reference numeral 20 denotes a bottom wall surface 8a of the base portion 6.
The guide pins are erected from the guide pins.
By being matched with the recessed portion 1c formed in the component 1, the component 1 can be reliably positioned with respect to the lower mold portion 4. Reference numeral 21 denotes a molded product S after injection molding.
Is an ejector pin for separating from the lower mold part 4.

Next, a description will be given of insert molding with resin based on the insert mold 2 having the above-described configuration.

First, as shown in FIG. 3, the slide piece 7 is opened left and right while the upper mold part 3 is raised, and
The component 1 is loaded into the lower mold part 4 so that the concave portion 1c of the component 1 is aligned with the above. Thereafter, the slide piece 7 is closed while lowering the upper mold part 3. At this time, as shown in FIG. 2, the tip end surface 14c of the sleeve body 14a protruding from the padding surface 17 of the upper mold part 3 first comes into contact with the pressing surface 1a of the component 1, and the component 1 The urging force of the spring 15 keeps being pressed against the bottom wall surface 8a of the lower cavity portion 8. Then, when the cavity A is formed by the cooperation of the upper cavity portion 5 and the lower cavity portion 8,
The part 1 is securely held in the cavity A and is ready for insert molding.

Thereafter, molten resin is injected into the cavity A from the gate 22, and the part 1 and the molten resin are integrally molded in the cavity A, so that the rotor S as a molded product as shown in FIG. It will be molded in the mold 2. At this time, the molten resin enters the concave portion 25 and reaches the concave portion 19 through the shaft hole 1 b of the component 1, and the shaft portion 23 is added to the component 1 by using the concave portions 19 and 25.
A, 23B and flanges 23a, 23b are integrally formed.
The sleeve member 14 is provided around the flange 23a.
Is in close contact with the pressing surface 1a of the component 1, so that the molten resin does not enter this contact portion, and as a result, the generation of burrs at the flange portion 23a is suppressed. Similarly, the bottom wall surface 8a and the contact surface 1d of the component 1 come into close contact with each other, so that the molten resin does not enter between them, and as a result, generation of burrs in the flange portion 23b is suppressed.

After the resin is cooled and solidified in the insert mold 2, the slide piece 7 is opened while the upper mold part 3 is raised. At this time, the molded product S is pushed up by the ejector pins 21 to separate the molded product S from the lower mold part 4. Thereafter, the molded product S is picked up by a robot hand (not shown) and transported to a predetermined pallet (not shown). In this way, the manufacturing process of the unmagnetized rotor S is completed. As a subsequent work, there is a step of magnetizing the magnetic material component 1 of the rotor S to form a magnet,
Through this process, the rotor S becomes a product that can be incorporated into the motor.

[0025]

Since the insert mold according to the present invention is constituted as described above, the following effects can be obtained. That is, a part is accommodated in a cavity formed by cooperation of a first cavity provided in a first mold part and a second cavity provided in a second mold part, and is inserted. In an insert mold for molding, the first
In the mold part, there is provided a part pressing means which is arranged to face one wall surface forming the second cavity part, presses the part against one wall surface of the second cavity part and holds the part in the cavity. As a result, the part does not dance in the cavity, the burr does not easily occur in the molded article, and a molded article having a high quality appearance can be produced. In addition, the dimensional accuracy of the molded product can be improved due to the fact that there is no displacement of the component in the cavity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing one embodiment of an insert mold according to the present invention.

FIG. 2 is a sectional view showing a main part of the insert mold shown in FIG.

FIG. 3 is a perspective view showing a lower mold portion of the insert mold shown in FIG. 1;

FIG. 4 is a sectional view showing a conventional insert mold.

FIG. 5 is a perspective view showing an example of an insert component incorporated in a rotor for a motor used for a shutter of a camera.

6 is a perspective view showing an example of an oscillating rotor created by applying the insert part shown in FIG. 5;

[Explanation of symbols]

A: cavity, 1: part, 1a: pressing surface of part, 2 ...
Insert mold, 3 ... Upper mold part (first mold part), 4 ...
Lower mold part (second mold part), 5: upper cavity part (first cavity part), 8: lower cavity part (second cavity part), 8a: bottom wall surface (one wall surface), 12 ... part pressing means, 13 ... guide hole, 14 ... sleeve member (movable member), 14c ... tip surface of sleeve member (movable member), 1
4d: through-hole, 15: coned disc spring (spring member), 18: pin member (fixing member), 18a: distal end surface of pin member (fixing member), 19: concave portion, 23A: shaft portion.

Claims (4)

[Claims] 1. A component is accommodated in a cavity formed by cooperation of a first cavity provided in a first mold and a second cavity provided in a second mold. In the insert mold for performing insert molding, the first mold portion is disposed so as to face one wall surface forming the second cavity portion, and the first cavity portion of the second cavity portion is disposed in the first mold portion. An insert mold, comprising: component pressing means for pressing the component against a wall surface and holding the component in the cavity. 2. The component pressing means is disposed in a guide hole provided in the first mold part and extending in a pressing direction of the component, and moves along the guide hole and closes the mold. A movable member having a distal end surface that abuts against a pressing surface of the component at a position facing the second cavity portion, and the movable member provided on the first mold portion and connecting the movable member to the pressing surface of the component. 2. The insert mold according to claim 1, further comprising: a spring member for urging the insert die. 3. The component pressing means is inserted into a through hole formed in the center of the movable member, is fixed to the first mold part, and forms a part of the first cavity part. 3. The insert mold according to claim 2, further comprising a fixing member having a front end surface. 4. The movable member is an elongated tubular sleeve member extending in a pressing direction of the component, and the spring member is a disc spring disposed at a position for urging a head portion of the sleeve member. Wherein the fixed member is an elongated pin member that is inserted into the through hole of the movable member and extends in the pressing direction of the component, and guides the movement of the sleeve member, and the distal end surface of the movable member The insert mold according to claim 3, wherein a concave portion forming a shaft portion integrally formed with the cylindrical part is provided in the insert mold.