JPH0957796A - Injection mold - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide an injection molding die in which a molding cycle (molding time) remains unchanged when molding a molded article having a thin portion and a lateral hole, and the molded article is not deformed. SOLUTION: At the time of mold clamping, a core portion 15 forming a molded product is sandwiched and fixed by a slide block 12 provided with a core block 13 provided with a lateral hole forming pin, and a locking pin 17 is held between the core block 13 and the slide block 12. It fits in the V-shaped groove 18 formed between. In the first step of mold opening, the locking pin 17 is separated from the V-shaped groove 18, and the core block 13 is slid in the slide block 12 in the direction orthogonal to the center line of the cylinder 4 by the elastic force of the built-in spring 14. In the second step of mold opening, the slide block 12 is slid by the angular pin 16 in the direction orthogonal to the center line of the cylinder 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention molds a molded product having a thin portion and a lateral hole, which is represented by a support member which supports a device for reading information recorded on a compact disc or the like so as to be movable in three dimensions. For injection molding molds for

[0002]

2. Description of the Related Art Conventionally, a molded product having a thin portion and a lateral hole, which is typified by a support for movably supporting a device for reading information recorded on a compact disc or an optical disc in a three-dimensional direction (see, for example, FIG. As shown in FIG. 4, when a thin wall portion 31 at several places and lateral holes 32 at 2-3 places are to be obtained by injection molding, as shown in FIG. In an injection molding die having a plate 34 and a moving-side die plate 35, a molten resin is injected into a cavity of the die from a sprue bush 36 provided on a fixed-side mounting plate 33, and pressure-holding and cooling are performed to obtain a molded product. After the solidification is completed, the mold opening is started, and the fixed side mold plate 34 and the moving side mold plate 35 are
As the space is opened, the slide blocks 38, 38 having the lateral hole forming pins 37 are provided along the guide groove provided on the moving-side mold plate 35 while holding the molded product in the cavity of the moving-side mold plate 35. A method of sliding the molten resin in a direction orthogonal to the injection direction and pulling out the lateral hole forming pin 37 is used.

[0003]

In this case, the hinge portion of the molded product is very thin and is a resin material which is easily deformed. When the mold is opened, the lateral hole forming pin 37 is pulled out (released).
Since the resistance is large, there is a problem that a part of the molded product is deformed. Further, even if the pulling-out speed of the lateral hole forming pin 37 is extremely reduced or the surface of the pin is smoothed in order to suppress the deformation of the molded product, the productivity is lowered and the variation of the deformation is also caused. A molded product having a satisfactory shape could not be obtained.

The present invention has been made in view of the above problems of the prior art, and its object is to reduce the molding cycle (molding time) when molding a molded product having a thin portion and a lateral hole. An object of the present invention is to provide an injection molding die that does not cause deformation of a molded product as it is.

[0005]

In order to achieve the above object, the present invention is an injection molding die for molding a molded product having a thin portion and a lateral hole without deformation, which is an injection molding machine. The molten resin injected from the cylinder through the sprue bush of the fixed side mounting plate into the mold is filled in the cavity formed by the fixed side moving plate and the moving side moving plate, and the mold is opened after holding pressure and cooling. In a mold for injection molding that takes out the molded product, at the time of mold clamping, the core part that forms the molded product is clamped and fixed with the slide block that has the core block with the lateral hole forming pin protruding and the built-in spring The other end of the locking pin, one end of which is fixed to the side mounting plate, is fitted into the V-shaped groove formed between the core block and the slide block, and the fixed side mold plate is mounted on the fixed side in the mold opening first step. Board Separately, the locking pin is removed from the V-shaped groove, and the elastic force of the built-in spring slides the core block in the slide block in the direction orthogonal to the cylinder center line. By moving the plate to separate the fixed mold plate and the movable mold plate from each other, the slide block can be slid in the direction orthogonal to the cylinder center line by the angular pin provided on the fixed mold plate. It has a feature.

In the present invention, the thin portion is a portion which is provided with hinge performance by bending and is thinner than other portions, specifically, a portion having a thickness of about 0.05 to 1.0 mm. The lateral hole means a hole in a direction orthogonal to the center line of the injection cylinder of the injection molding machine, and has a depth three times or more the diameter.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
This will be described together with the illustrated example. FIG. 1 shows a cross section of an injection molding machine including an injection molding die of the present invention during mold clamping, and FIG. 2 shows a cross section of a first step when the injection molding die of the present invention is opened. 3 shows a cross section of the second step when the mold for injection molding of the present invention is opened.

In FIG. 1, 1 is an injection mechanism which constitutes an injection molding machine, and 2 is an injection molding die. 3 is a hopper for introducing a resin material, 4 is a cylinder having a heater 5, 6
Is a screw for transferring the resin material in the cylinder 4, and the screw 6 is operated by a hydraulic motor 7.

Reference numeral 8 is a fixed side mounting plate, 9 is a fixed side mold plate, and 10
Is a moving side template. Reference numeral 11 is a sprue bush through which the molten resin first passes in the mold, and 12 is a slide slideable in a direction orthogonal to the center line of the cylinder 4 along a guide groove (not shown) provided in the moving side mold plate. It is a block. 13 is a core block with a built-in spring 14,
The core block 13 can slide in the slide block 12 in a direction orthogonal to the center line of the cylinder 4 by the elastic force of the spring 14. The core block 15 that forms a molded product is sandwiched and fixed by the slide blocks 12 that house the core block 13. Reference numeral 16 is an angular pin attached to the fixed-side mold plate 8, penetrating the slide block 12, and one on each side of the core portion 15.
An angular pin is installed. Reference numeral 17 denotes a locking pin, one end of which is fixed to the fixed side mounting plate 8 and the other end of which is fitted into a V-shaped groove 18 formed by the slide block 12 and the core block 13.

A method of injection molding using the injection molding machine configured as described above will be described below.

In the injection molding machine shown in FIG. 1, the molten resin injected from the cylinder 4 through the sprue bush 11 into the mold is filled in the cavity 19, held at a predetermined pressure for a certain period of time, and then cooled to obtain a molded product. After the solidification of is completed, the mold is opened. The mold opening consists of a first step and a second step. That is, in the first step, as shown in FIG. 2, when the moving side mounting plate (not shown) is retracted in the direction away from the cylinder, the action of the spring 20 causes
The fixed side template 9 is pulled away from the fixed side mounting plate 8,
The locking pin 17 separates from the V-shaped groove 18 formed between the slide block 12 and the core block 13. When the locking pin 17 separates from the V-shaped groove 18, the core block 13 slides in the slide block 12 in the direction orthogonal to the center line of the cylinder 4 (see FIG. 1) by the elastic force of the built-in spring 14 to form a lateral hole. The forming pin 21 comes off the injection-molded product. Also at this stage,
Since the fixed side mold plate 9, the slide block 12, and the moving side mold plate 10 surrounding the core portion 15 forming the molded product are in a clamped state and the angular pin 16 does not operate,
Since the molded product is fixed, it does not deform.

Next, in the second step of mold opening, as shown in FIG. 3, the moving side mounting plate (not shown) is further retracted in the direction away from the cylinder, and the moving side mold is fixed integrally therewith. When the plate 10 is moved in the direction away from the cylinder, the slide block 12 is guided by the angular pins 16 and is separated from the fixed-side mold plate 9 while the moving-side mold plate 10 is moved.
It slides in a direction orthogonal to the center line of the cylinder 4 along a guide groove (not shown) provided above. Thus,
Molded product is released from the mold clamped state, protruding pin (not shown)
With a slight poke, the molded product having the shape shown in FIG. 4 can be easily taken out without deformation.

Since the series of operations described above occur in a chain reaction, the molding cycle does not become longer than in the conventional method.

[0014]

According to the present invention, a molding cycle (molding time) is used when molding a molded product having a thin portion and a lateral hole.
It is possible to provide a mold for injection molding in which the molded product is not deformed as it is.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an injection molding machine including an injection molding die of the present invention during mold clamping.

FIG. 2 is a cross-sectional view of the first step when the mold for injection molding of the present invention is opened.

FIG. 3 is a cross-sectional view of a second step when the mold for injection molding of the present invention is opened.

FIG. 4 is a perspective view showing an example of a molded product having a thin portion and a lateral hole.

FIG. 5 is a sectional view of a conventional injection molding die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Injection mechanism 2 ... Injection-molding die 4 ... Cylinder 8 ... Fixed side mounting plate 9 ... Fixed side template 10 ... Moving side template 11 ... Sprue bush 12 ... Slide block 13 ... Core block 14 ... Spring 15 ... Core Part 16 ... Angular pin 17 ... Locking pin 18 ... V-shaped groove 19 ... Cavity 20 ... Spring 21 ... Horizontal hole forming pin

Claims (1)

[Claims] 1. A mold for injection molding for molding a molded product having a thin portion and a lateral hole without deformation, which is formed in a mold of a cylinder of an injection molding machine through a sprue bush of a fixed side mounting plate. In the injection molding die, the injected molten resin is filled in the cavity formed by the fixed-side mold plate and the moving-side mold plate, and the mold is opened after pressure retention and cooling to take out the molded product. , The other end of the locking pin whose one end is fixed to the fixed side mounting plate is clamped / fixed to the core portion forming the molded product by the slide block having the core block in which the lateral hole forming pin is projecting and the spring is built-in. It fits in the V-shaped groove formed between the core block and the slide block, and in the mold opening first step, the fixed-side mold plate is separated from the fixed-side mounting plate to separate the locking pin from the V-shaped groove, Within The core block is slid in the slide block in the direction orthogonal to the cylinder center line by the elastic force of the stored spring, and in the mold opening second step, the moving side mold plate is moved to move the fixed side mold plate and the moving side mold. An injection molding die, characterized in that the slide block is slidable in a direction orthogonal to the cylinder center line by an angular pin provided on the stationary mold plate by separating the plate from the plate.