JPH1158443A - Insert molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To set and support easily an insert work regardless of the length of an insert molded product by adopting a means for moving the insert work in a cavity by resin pressure. SOLUTION: An operation pin 7 used combinedly for supporting an insert work 13 is inserted movably forward and backward into a cavity 3 recessed on a parting face of a movable mold 1. A piston rod 11 of an operation cylinder 10 set on a movable platen is brought into contact with the operation pin 7 to control the backward movement of the operation pin 7 by resin pressure. The insert work 13 is inserted into the cavity 3 and supported by the operation pin 7. The insert work 13 is pressed by the injection of resin 14. The resin 14 is filled into the cavity 3 while the insert work 13 is moved backward together with the operation pin 7 to a cavity end wall by the operation cylinder 10 at the same time that the resin pressure is received to mold an insert molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insert molding method for integrally molding an insert work such as a metal product and a resin in a mold.

[0002]

Generally, in insert molding, it is necessary to set an insert work at a predetermined position in a cavity before closing a mold. Insert molding, which covers the bottom of the molded product with metal, requires extra work because a plate-shaped insert work must be inserted and fixed at the innermost part of the cavity, and it is a special specification regardless of the length of the insert molded product In many cases, an insert device is used.

In addition, in the case of a long insert molded product, an insert device having a long insert arm is required in order to insert the insert work deep into the cavity, so that a large mold opening / closing stroke is required. In some cases, a disadvantage arises in that a molding machine having a specification one class higher than the case must be used.

The present invention has been made in view of the above circumstances. It is an object of the present invention to adopt a method of moving an insert work in a cavity by resin pressure, thereby setting an insert work regardless of the length of an insert molded product. It is another object of the present invention to provide a new insert molding method that can easily perform the insert molding and the support.

[0005]

SUMMARY OF THE INVENTION According to the present invention having the above object, a cavity recessed in a movable parting surface is provided.
The operating pin, which also supports the insert work, can be inserted and retracted freely, the piston pin of the operating cylinder provided in the movable plate abuts on the operating pin, and the operating cylinder can control the retreat of the operating pin by the resin pressure. None, after the insert work is inserted into the cavity and supported by the operation pins, the insert work is pressed by resin injection, and the insert work is retracted to a predetermined position together with the operation pins while receiving the resin pressure by the operation cylinder. While filling the cavity with resin, an insert molded product is molded.

The resin filled in the cavity according to the present invention contains a foaming agent or gas. The resin is filled into the cavity while receiving the foaming pressure as the resin pressure and retracting the insert work together with the operating pin to a predetermined position. It is also that.

In such insert molding, the insert work is reliably set in the cavity regardless of the length of the insert molded product, and molding defects due to the fall of the insert work after the setting are solved. An insert molded product is obtained. In addition, since it is not necessary to insert to the deepest part of the cavity even if it is long, a long insert arm is unnecessary even when using an insert device. The disadvantage of having to adopt is solved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, reference numeral 1 denotes a fixed mold, 2 denotes a movable mold, and a cavity 3 of a short-column-shaped molded product opened at a parting surface is recessed in a front portion, and a fixed cavity 3 faces the cavity. In the sprue 4 drilled in the center of the parting surface of the mold 1,
The nozzle 5 a of the injection device 5 is in contact with the fixed plate 6.

An operation pin 7 is provided at the center of the cavity 3.
Is positioned so as to be able to advance and retreat from the hollow portion 8 at the rear of the movable die. A piston rod 11 of a hydraulically operated operation cylinder 10 provided in the movable platen 9 is in contact with a rear end of the operation pin 7 via an operation plate 12, and the operation cylinder 10 causes the operation pin 7 to retreat by resin pressure. Can be controlled.

In the insert molding using the mold, first, in the mold open state, the operating pin 7 is moved forward by the operating cylinder 10, and the tip end surface is fixed to the opening of the cavity 3 as an insert work support. Next, an insert work 13 made of a metal plate having substantially the same diameter as the cavity 3 and having a peripheral edge press-formed is inserted into the opening until it comes into contact with the distal end surface of the operation pin 7. The insert work 13 is set in the opening so as not to fall into and out of the cavity 3 due to the peripheral thickness and the operation pins 7.

Next, after the movable mold 2 is moved forward toward the fixed mold 1 to close and close the mold, the operating cylinder 10
To apply a pressure lower than the resin pressure to the operation pin 7. Thereafter, the nozzle 5a of the injection device 5 in contact with the fixed mold 1
Then, the molten resin 14 is injected through the sprue 4 into the gap between the openings of the cavity 3. By this injection, the insert work 13 moves backward to the innermost end wall of the cavity 3 while receiving the resin pressure together with the operation pin 7. Resin 14 is sequentially filled in the cavity 3 expanded with this retreat, and when the insert work 13 comes into contact with the end wall and becomes unable to retreat, injection filling is completed, and the insert work 13 adheres to one side surface. An insert molding is formed.

When the injection of a predetermined amount of molten resin is completed or when the insert work 13 retreats to the above-mentioned end wall, the pressurization by the operation cylinder 10 is stopped, and the process shifts to pressure holding and cooling to open the mold. The mold release is performed after the mold is opened. The mold release can be easily performed by re-advancing the operation pin 7 to the open end by the operation cylinder 10, and accordingly, the operation pin 7 and the operation cylinder 10 are protruded. It can also be used as a device.

The resin 14 filling the cavity 3 is
When a foaming agent or a gas is contained, the insert work 1 is received together with the operation pin 7 while receiving the foaming pressure as a resin pressure.
The cavity 3 can be filled with the resin 14 while the cavity 3 is retracted to the end wall of the cavity 3. Therefore,
The insert molding according to the present invention can be employed as it is for foam molding.

As described above, the insert work 13 fitted in the cavity 3 is supported by the operation pin 7, and the insert work 13 is retracted to the cavity end wall together with the operation pin 7 while receiving the resin pressure by the operation cylinder 10. In the insert molding in which the resin 14 is injected and filled, the setting of the insert work 13 in the cavity 3 can be surely performed, the molding failure due to the fall of the insert work 13 after the setting is eliminated, and it is necessary to insert the deepest part of the cavity 3. Therefore, the insert work becomes easy, and the quality of the insert molded product is improved.

[Brief description of the drawings]

FIG. 1 is a schematic view of a mold used for carrying out the insert molding method of the present invention, and is an explanatory diagram of an initial stage in which a resin is injected into a cavity.

FIG. 2 is an explanatory diagram when injection filling is completed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 3 Cavity 4 Sprue 5 Injection device 5a Nozzle 7 Operation pin 10 Operation cylinder 11 Piston rod 12 Operation plate 13 Insert work 14 Resin

Claims (2)

[Claims] An operating pin serving also as a support for an insert work is movably inserted into a cavity formed in a movable parting surface, and a piston rod of an operating cylinder provided in a movable plate is brought into contact with the operating pin. In contact with the operating cylinder, it is possible to control the retreat of the operating pin by the resin pressure by the operating cylinder. After the insert work is inserted into the cavity and supported by the operating pin, the insert work is pressed by injection of resin, and the operating cylinder is pressed. An insert molding method characterized in that a cavity is filled with resin while the insert work is retracted to a predetermined position together with an operation pin while receiving a resin pressure, thereby forming an insert molded product. 2. The resin filled in the cavity contains a foaming agent or gas, and while receiving the foaming pressure as the resin pressure, the resin is filled in the cavity while the insert work is retracted to a predetermined position together with the operation pin. The insert molding method according to claim 1, wherein