JP2546940Y2 - Injection mold - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mold for producing a synthetic resin product.

[0002]

2. Description of the Related Art As shown in FIG. 4, an injection molding die 1 of a synthetic resin product comprises a fixed die 1a and a movable die 1b joined to and separated from the fixed die 1a. This is a structure in which a product molding die surface 1c is formed on the surface in contact with the molding die 1b. After the mold is opened, the molded product is brought into close contact with the product molding die surface 1c on the movable die 1b side and is taken out.

[0003] In the conventional injection mold 1 shown in FIG.
Immediately after opening the mold, the product molding die surface 1c
Therefore, the mold releasability between the molded article W and the fixed mold 1a when the mold is opened.
The molded product W and the fixed mold 1a were in close contact with each other and changed to the molded product W.
Shape and damage occur. This is a good surface quality with no grain
There is a problem that it often occurs in shaped articles.

In order to solve such a problem, a mold is required.
Insert the air extrusion pin into the air extrusion pin insertion hole
It is provided to be able to move forward and backward, and this air push pin is moved forward
Air push pin and air push pin
Spouts from between the insertion holes to release the molded product from the mold
As in the invented real-Sho 46-935 No. and Japanese Utility Model 4 5
No. -3182.

[0005]

[Problem to be solved by the invention ]
Spouts from between the ejection pin and the air ejection pin insertion hole
The molded product is released from the mold by compressed air,
It is disclosed that a molded article is cooled in a short time. Follow
The fact that this cooling action is also performed means that the compressed air is at room temperature.
Or below room temperature. However, this quenching
The molded product shrinks and deforms due to rejection, and adheres to the fixed mold
And forcibly extrude it with an air extrusion pin
Has the problem of causing deformation and damage of the molded product due to
You.

An object of the present invention is to provide a molded product with shrinkage deformation and damage.
An object of the present invention is to provide an injection mold capable of preventing mold leakage and quickly and surely releasing the mold .

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to provide an injection molding die for a synthetic resin product comprising a fixed die and a movable die, wherein a surface of the product forming die on the fixed die side. A valve seat opening for air supply, a valve shaft that moves forward and backward by an air cylinder to move out and out of the product forming die surface, and opens and closes the valve seat hole; A switching valve for controlling air supply to an air cylinder, an air source and the switching valve
Between the heater that heats the air and the heater temperature
And a temperature controller .

[0008]

With the above arrangement, the valve shaft is moved backward during molding to be positioned in the valve seat hole, the front end surface of the valve shaft is flush with the product forming die surface on the fixed mold side, and the valve seat hole is closed. State. When the movable mold is moved backward to open the mold, air heated to a predetermined temperature by a heater is supplied to the front and rear chambers of the air cylinder to advance the valve shaft, and the molded product is pushed out by the valve shaft. At the same time, heated air is supplied from the opened valve seat hole to the gap between the molded product and the product mold surface on the fixed mold side to release the molded product.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an injection molding die,
a and a movable die 1b, and a product molding die surface 1c is formed on a contact surface between the fixed die 1a and the movable die 1b.

In the present invention, as shown in FIG.
A valve seat hole 2 for supplying air is opened in the product molding die surface 1c on the side a, and an air cylinder 3 is fixedly provided at this position. A piston 4 and a valve shaft 5 which is integral with the piston 4 and opens and closes the valve seat hole 2 and protrudes from the product molding surface 1c of the fixed mold 1a when the air cylinder 3 is opened are provided in the air cylinder 3. Have been.

A spring 6 is provided in the front chamber 3a of the air cylinder 3 for pushing the piston 4 in a backward direction from the piston 4 and the front chamber 3a communicates with the valve seat hole 2. Further, air conduits 13a and 13b are connected to the front chamber 3a and the rear chamber 3b of the air cylinder 3.

[0012] The air conduit 13a, 13b is the flow regulating valve 12 is connected to the air source 7 via the switching valve 11, the heater 8 between the d <br/> A source 7 and the switching valve 11, This heater 8
A temperature controller 9 is provided for controlling the temperature of the device.

Since the present invention has the structure as described above, when the movable mold 1b is brought into contact with the fixed mold 1a and the mold is closed, the air supply is shut off by the switching valve 11, and the piston 4 is moved by the spring 6. retracted, and backward movement of the valve shaft 5 is positioned on the valve seat hole 2, the stationary die 1 to the distal end surface of the valve shaft 5
The same side as the product mold surface 1c on the side a, and the valve seat hole 2
Is closed.

After molding the molded product W by injecting the synthetic resin into the gap between the product molding die surfaces 1c, the movable die 1b is moved backward to open the mold. At this time, the switching valve 11 is switched to the front and rear chambers 3 a and 3 b of the air cylinder 3 by the heater 8.
Supply air heated to a predetermined temperature . This allows
As shown in FIG. 3, the valve shaft 5 moves forward and protrudes from the product forming die surface 1c on the fixed die 1a side.
With extruding a shaped article W and the solid from the opened valve seat hole 2
The heated air is supplied to a gap between the mold 1a and the product molding surface 1C to release the molded article W from the mold. The air heating temperature
Controls the temperature of the heater 8 by the temperature controller 9.
To a predetermined temperature.

[0015] By supplying air that has been heated to a temperature gap Therefore predetermined heater 8 with the product the mold surface 1C of the molded product W and the fixed mold 1a side from the valve seat hole 2, the temperature gradients in the shaped article W Can be released without the occurrence of

[0016]

As described above, in the present invention, a valve seat hole for supplying air is opened on the surface of the product forming die on the fixed die side, and the product is moved forward and backward by an air cylinder to protrude and retract from the surface of the product forming die. A valve shaft for opening and closing the valve seat hole, a switching valve for controlling the supply of air to the valve seat hole and the air cylinder, an air source and the switching valve
Between the heater that heats the air and the heater temperature
A temperature controller is provided , and when the mold is opened, the molded product that is in close contact with the product mold surface on the fixed mold side is pushed out by the advance movement of the valve shaft, and the gap between the molded product and the product mold surface on the fixed mold side is formed. by controlled heater by a temperature controller
Since the air heated to a predetermined temperature is supplied, a temperature gradient occurs in the molded product when the mold is opened.
The mold is released quickly and surely without any problems , and prevents shrinkage deformation and damage of the molded product, thereby improving quality.

[Brief description of the drawings]

FIG. 1 is a sectional view of an injection mold according to the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is an operation diagram showing a release state of a molded product.

FIG. 4 is a cross-sectional view of a conventional injection mold.

FIG. 5 is an explanatory diagram of a conventional problem.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Injection molding die 1a Fixed mold 1b Movable mold 1c Product molding die surface 2 Valve seat hole 3 Air cylinder 4 Piston 5 Valve shaft 6 Spring 7 Air source 8 Heater 11 Switching valve 12 Flow control valve 13a Air conduit 13b Air conduit

Claims (1)

(57) [Scope of request for utility model registration] 1. An injection molding die for a synthetic resin product comprising a fixed mold and a movable mold, wherein an air supply valve seat hole formed in the product molding surface of the fixed mold and an air cylinder move forward and backward. A valve shaft that protrudes and retracts from the surface of the product forming die and opens and closes the valve seat hole, a switching valve that controls the supply of air to the valve seat hole and the air cylinder, and an air source and the switching valve.
A heater for heating air and a temperature controller for controlling heater temperature
An injection mold comprising a controller .