JPH1158465A - Mold for manufacturing infection molded product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold for releasing an injection molded product in a good manner. SOLUTION: One ends of ejector pins are inserted into opening sections 21a of a block (rotating piece 21) constituting a mold carried on a movable side base and rotating while being brought into contact with a molded product, while the other ends are supported on the rotatable piece in an extrusion plate. Or a spring 41 is provided between the movable side base and the rotating piece 21 to return the rotating piece to the original position after releasing the molded product. The ejector pins can be rotated without disturbing the movement of the rotating piece by the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for producing a molded product by an injection molding method.

[0002]

2. Description of the Related Art Many metal or resin products are manufactured by injection molding. The injection molding machine generally has a mold composed of a fixed mold and a movable mold, and a heating cylinder that injects a metal or plastic material heated and melted into the fixed mold. . After cooling and fixing, the molded product is obtained by separating the movable mold from the fixed mold and then extruding the molded product with an extrusion pin.

In the manufacture of a drum-shaped electrophotographic photosensitive member, flanges are attached to both ends of a cylindrical base. When, for example, a helical gear or the like is provided on the flange, it is common to use a frame (rotating frame) that freely rotates with respect to this portion as a mold for the flange, so as not to hinder release. is there. However, if the area formed by the rotating top is large and the area of the part formed by the usual mold opening is small, the installation place of the ejector pin (EP) for pushing the product out of the mold is reduced. (Conventionally, it is said that the EP moves in the mold opening direction and cannot be installed in the rotating frame.)
Further, if the EP cannot be installed in a well-balanced manner, the releasability of the product deteriorates, which leads to deformation and deterioration of dimensional accuracy.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a mold for manufacturing an injection-molded article which can extrude the above-mentioned problematic molded article in a well-balanced manner.

[0005]

According to the present invention, firstly, one end of an ejector pin is carried on a movable base to form a mold, and a hole of a top which can rotate in contact with a molded product. And the other end thereof is supported by a rotatable block in an extrusion plate, and the ejector pin can rotate without hindering the movement of the rotating piece. Provided.

Second, the first injection-molded article is characterized in that a spring is arranged between the movable base and the rotary piece, and the rotary piece is returned to the original position after the molded article is released. Are provided.

Third, between the movable base and the rotatable block in the extruding plate or between the rotating piece and the extruding plate, a projection having a tip at the tip is fixed to the block or the extruding plate, and the projection is released. By forming a concave portion for receiving the time when the rotating piece is provided, and providing a spring between the movable base and the rotating piece, the rotating piece is positively rotated at the time of releasing the molded product, and after the mold release, the rotating piece is rotated. Is returned to the original position, and the mold for manufacturing the first injection-molded article is provided.

Fourthly, the tip of the ejector pin is provided with a scent, and a spring is provided between the movable base and the rotating piece. When the mold is opened (during release), the ejector pin is inserted into the recess of the rotating piece. For positively rotating the rotating piece, and removing the inserted ejector pin from the recess of the rotating piece at the time of closing the mold, and returning the rotating piece to the original position, for manufacturing the first injection molded article. A mold is provided.

Fifth, there is provided a mold for manufacturing the above-mentioned first injection-molded article, characterized in that the rotary piece is rotated by the power of a rack and a pinion based on a mold opening / closing force.

Sixth, when the molded product protrudes at an angle α at a contact portion between the ejector pin in the rotating top and the molded product, α ≧ the rotation angle of the die top. A mold for manufacturing an injection molded article is provided.

Seventh, one end of the ejector pin other than the ejector pin penetrating through the rotating frame is inserted into the movable mold, and the other end is supported by an extrusion plate.
The first injection molded product manufacturing die is provided, wherein the tip of the ejector pin inserted into the movable side die is formed to be more convex than the movable side base.

[0012] The mold for producing an injection-molded article of the present invention comprises:
(1) One end of the EP is fixed to a block rotatably supported by a bearing on a push plate of the EP, and the other end is inserted into a hole of the rotating piece. (Product) while moving with
To extrude. At this time, molded products (products)
Does not move with the rotation of the rotating top. According to this, it is possible to release the product with good balance. (2) E
If the tip of P is made to bite, the releasability is improved even without turning the product.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail. Here, the molding material is resin, but it is needless to say that metal may be used. As seen in FIG. 1, in the mold of the present invention, the molten resin from the liner 11 is
It is introduced into a gap formed by the fixed mold and the movable rotary piece 21. In the figure, 1 is a fixed-side mold, 22 is a movable-side base, 23 is an extrusion plate, and 24 is a block. The rotating piece 21 has a bearing 31 on a base 22.
, And can rotate in a certain direction when the mold is released. The rotation of the rotary top 21 and the control of the rotation are performed by a rack and pinion based on the opening and closing force of the mold, or other power energy obtained from a hydraulic pressure, a motor, or the like. Further, the block 24 is supported by the extrusion plate 23 by a bearing 32, and can be freely rotated by the movement of an ejector pin (EP).

One end of the EP is stopped by the block 24, and the other end is inserted into the hole 21a of the rotating piece. The hole 21a has a long hole shape. FIG. 2 schematically shows the structure of the rotating top 21. Here, rotating top 2
EP is inserted into one of the holes 21a, and is pulled by a spring 41 in a certain direction. The rotating piece 21 is rotated in the direction of the arrow when releasing the mold. The number of springs 41 and the number of EPs may be arbitrarily selected. In addition,
It is necessary to rotate the rotary top for producing hasbakia at the same time as the torsion angle α at the time of release from the mold.

FIG. 1 shows the positional relationship between the mold and the rotating piece during molding. When the mold is released, the fixed mold 1 is stationary, but the rotating piece 21 and the base 22 are on the right side of the drawing. Move towards At this time, the surface where the molded product and the EP are in contact
The molded article does not rotate, but the EP rotates, so that the molded article is scratched. The rotation of the rotary top 21 is performed by a rack and pinion or the like. As shown in FIG. 3A, the opening of the rotary top 21 is received by a tapered recess 21b provided in the rotary top 21. It can also be performed as follows. The protrusion 51 inserted into the concave portion 21b of the rotary piece may be provided on the extrusion plate. FIG. 3B is a view as viewed from IIIB-IIIB in FIG. 3A, and the upward arrow attached to FIG.
1 shows how the rotation top 21 is moved by the movement of No. 1. Further, it is also possible to rotate the rotating top by providing the taper mechanism to the EP. This part requires that the EP has sufficient strength.

At the contact portion between the EP and the product in the rotating piece, as shown in FIG. 4, the rotating piece 21 has a narrowing of ∠α, and by setting α ≧ the rotation angle of the die piece,
It is possible to minimize the damage to the product due to the EP rotating and moving in the same manner as the rotating top 21 without hindering the rotation of the rotating top 21 at the time of releasing the mold. Further, when the EP can be placed in a portion to be formed by a normal mold opening in addition to the insertion of the EP into the hole 21a of the rotating top, as shown in FIG. By making it more convex by b, the rotation of the rotating piece can be prevented from rotating the product, and the releasability can be improved.

[0017]

【The invention's effect】

(1) According to the first aspect of the present invention, the EP penetrates through the rotary piece, but since the non-product side is fixed to a rotatable block in the extrusion plate, the movement of the rotary piece is not hindered. The EP can be arranged in the rotating top, and the product can be released from the mold with good balance. (2) According to the second aspect of the present invention, the rotating top after product release is returned to the original position by the force generated by the spring.
The positional relationship between the part formed by the normal mold opening and the part formed by the rotating piece can be automatically changed each time a product is obtained. (3) According to the third aspect of the invention, in addition to the function of the above (2), since the rotating top is positively moved by the force in the rotating direction generated by the camber of the gradient, the releasability is improved. Can be. (4) According to the invention of claim 4, the function of (3) is performed by
By providing P, the number of mold components can be reduced. (5) According to the invention of claim 5, since the rotation amount of the rotating piece according to the mold opening amount is controlled by the functions of the rack and the pinion, the same effect as the above (3) can be obtained. In addition, the transferability to a mold-shaped product can be improved. (6) According to the sixth aspect of the present invention, the EP shape is concave at a larger angle than the rotation angle of the rotating top (product convex), so that the product is not damaged by the EP without hindering the movement of the rotating top. Can be limited. (7) According to the seventh aspect of the present invention, the EP arranged in the part formed only by the normal mold opening is made to bite into the product (product recess), so that the rotation of the product is prevented, and the rotation frame of the product is prevented. The releasability of the part can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a mold for manufacturing an injection-molded article of the present invention.

FIG. 2 is a schematic explanatory view of a rotating top.

FIG. 3 is a diagram showing a means for rotating a rotating top.

FIG. 4 is a diagram in which a contact portion between an ejector pin and a molded product in a rotating piece has an angle.

FIG. 5 is a diagram in which an ejector pin is arranged so as to protrude by b from the movable base.

[Explanation of symbols]

 1 Fixed die 9 Product 11 Runner 21 Rotating piece 21a Hole 21b recess 22 Movable base 23 Movable extrusion plate 24 Movable block 31,32 Bearing 41 Spring 51 Projection

Claims (7)

[Claims] 1. One end of an ejector pin is inserted into a hole of a frame which is supported by a movable base and constitutes a mold and can rotate in contact with a molded product, and the other end is rotatable in an extrusion plate. A mold for manufacturing an injection-molded article, supported by a block, wherein the ejector pin can rotate without hindering the movement of the rotating piece. 2. The mold according to claim 1, wherein a spring is arranged between the movable base and the rotating piece, and after releasing the molded product,
A mold for manufacturing an injection-molded product, wherein the rotating piece is returned to an original position. 3. The mold according to claim 1, wherein a protrusion having a odor at its tip is fixed to the block or the extrusion plate between the movable side base and the rotatable block in the extrusion plate or between the rotary piece and the extrusion plate. A concave portion for receiving the projection at the time of release is formed on the rotary piece, and a spring is provided between the movable base and the rotary piece, so that the rotary piece is positively rotated at the time of mold release,
A mold for manufacturing an injection-molded article, wherein the rotating piece is returned to its original position after release. 4. The mold according to claim 1, wherein the tip of the ejector pin is provided with a fragrance, a spring is provided between the movable base and the rotating piece, and the ejector pin is rotated when the mold is opened (during release). The injection molding product is characterized in that the rotating top is positively rotated by inserting it into the recess of the top, and the ejector pin inserted is removed from the recess of the rotating top when the mold is closed, and the rotating top is returned to the original position. Manufacturing mold. 5. The mold according to claim 1, wherein the rotating piece is rotated by the power of a rack and a pinion based on a mold opening / closing force. 6. The mold according to claim 1, wherein said molded product has an angle α at a contact portion between the ejector pin in the rotating piece and the molded product.
A mold for manufacturing an injection-molded product, wherein α ≧ the rotation angle of the mold top when protruding. 7. The mold according to claim 1, wherein one end of an ejector pin other than the ejector pin penetrating through the rotating piece is inserted into the movable mold, and the other end is supported by an extrusion plate. A mold for manufacturing an injection-molded product, wherein a tip of an ejector pin inserted into a movable-side mold is formed to be more convex than a movable-side base.