JPH057426U - Injection mold - Google Patents

Abstract

(57) [Summary] [Purpose] The present invention provides an injection molding die that improves the quality by promptly and reliably releasing the molded product when the mold is opened, preventing deformation and damage of the molded product. [Structure] A valve seat hole 2 for air supply is opened in a product molding surface 1c of a fixed mold 1, and an air cylinder 3 moves back and forth to project and retract in the product molding surface 1c, and the valve seat hole 2 Is provided with a valve shaft 5 for opening and closing the valve, and a switching valve 3 for controlling air supply to the valve seat hole 2 and the air cylinder 3. When the mold is opened, the product molding surface 1c on the fixed mold 1 side is moved by the forward movement of the valve shaft 5. The molded product W that is in close contact with the molded product W is pushed out, and at the same time, the room temperature or heated air is supplied to the gap between the molded product W and the product molding die surface 1c on the fixed mold 1 side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an injection mold for manufacturing synthetic resin products.

[0002]

[Prior Art]

 As shown in FIG. 4, a synthetic resin product injection molding die 1 is composed of a fixed die 1a and a movable die 1b which is joined to and separated from the fixed die 1a. The fixed die 1a and the movable die 1b are opposed to each other. It has a structure in which the product molding surface 1c is formed on the surface, and after the mold is opened, it is taken out in close contact with the product molding surface 1c on the movable mold 1b side.

[0003]

[Problems to be solved by the device]

 In the conventional injection mold 1, as shown in FIG. 5, the product molding surface 1c is in a depressurized state immediately after the mold is opened, so that the mold release property between the molded product W and the fixed mold 1 is poor when the mold is opened. The molded product W and the fixed mold 1a come into close contact with each other, and the molded product W is deformed and damaged. There is a problem that this often occurs in molded products with good surface quality without grain.

An object of the present invention is to provide an injection molding die that solves the above conventional problems.

[0005]

[Means for Solving the Problems]

 The gist of the present invention for achieving the above-mentioned object is to provide an air supply for a synthetic resin product injection molding die comprising a fixed die and a movable die, which is provided on the surface of the product die on the fixed die side. Valve seat hole, a valve shaft that moves forward and backward by an air cylinder and then appears and disappears in the product molding die surface, and opens and closes the valve seat hole, and a switching valve that controls the supply of air to the valve seat hole and the air cylinder. It is equipped with.

[0006]

[Action]

 With the above configuration, during molding, the valve shaft is moved backward and positioned in the valve seat hole, the tip surface of the valve shaft is flush with the product molding surface of the fixed mold side, and the valve seat hole is closed. .. When the movable mold is moved backward and the mold is opened, air is supplied to the front and rear chambers of the air cylinder to move the valve shaft forward, the molded product is pushed out by the valve shaft, and the molded product is opened from the valve seat hole. Air is supplied to the gap between the mold surface of the fixed mold and the product, and the molded product is released from the mold.

[0007]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an injection molding die, which comprises a fixed die 1a 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. 2, a valve seat hole 2 for air supply is opened in the product molding die surface 1c on the fixed die 1a side, and an air cylinder 3 is fixedly installed at this portion. In the air cylinder 3, a piston 4 and a valve shaft 5 which is integral with the piston 4 and which opens and closes the valve seat hole 2 and projects from the product molding die surface 1c on the fixed die 1a side when opened are provided. It has been burned.

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

The air conduits 13 a and 13 b are connected to an air source 7 via a flow rate adjusting valve 12 and a switching valve 11, and if necessary, a heater 8 is provided between the air source 7 and the switching valve 11, and the heater A temperature controller 9 for controlling the temperature of 8 is provided.

Since the present invention has the above-described structure, during the molding in which the movable mold 1b is opposed to the fixed mold 1a and the mold is closed, the supply of air is shut off by the switching valve 11 and the piston 4 by the spring 6 is cut off. When the valve shaft 5 is moved backward, the valve shaft 5 is moved backward and positioned in the valve seat hole 2, the tip end surface of the valve shaft 5 is flush with the product molding surface 1c of the fixed mold 1 side, and the valve seat hole 2 is closed. State.

After the synthetic resin is injected into the gap between the product molding surface 1c to mold the molded product W, the movable mold 1b is moved backward to open the mold. At this time, the switching valve 11 is switched to supply air to the front and rear chambers 3a and 3b of the air cylinder 3. As a result, as shown in FIG. 3, the valve shaft 5 moves forward and protrudes from the product molding surface 1c on the fixed mold 1 side, the molded product W is extruded by the valve shaft 5, and the opened valve seat is formed. Air is supplied from the hole 2 to the gap between the molded product W and the product molding surface 1C on the fixed mold 1 side to release the molded product W from the mold.

The air supplied from the valve seat hole 2 to the gap between the molded product W and the product molding surface 1C on the fixed mold 1 side may be room temperature, but the air heated to a predetermined temperature by the heater 8 is supplied. As a result, the molded product W can be released from the mold without causing a temperature gradient.

[0014]

[Effect of the device]

 As described above, according to the present invention, a valve seat hole for air supply is opened in the product molding die surface of the fixed mold side, and it is moved forward and backward by the air cylinder to project and retract in the product molding die surface, and the bracket valve seat hole is formed. A molded product that has a valve shaft that opens and closes and a switching valve that controls the supply of air to the valve seat hole and the air cylinder, and that is in close contact with the mold surface of the fixed mold by the forward movement of the valve shaft when the mold is opened. In addition to pushing out, the air is heated to room temperature or heated in the gap between the molded product and the product molding surface on the fixed mold side. Reliable mold release prevents deformation and damage of molded products and improves quality.

[Brief description of drawings]

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

FIG. 2 is an enlarged view of part A of FIG.

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

FIG. 4 is a sectional view of a conventional injection molding die.

FIG. 5 is an explanatory diagram of conventional problems.

[Explanation of Codes] 1 Injection Mold 1a Fixed Mold 1b Movable Mold 1c Product Mold 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 Valves 13a, 13b Air conduit

Claims (1)

[Claims for utility model registration] [Claim 1] In an injection molding die of a synthetic resin product comprising a fixed die and a movable die, a valve seat hole for air supply is opened in the surface of the product die on the fixed die side. And a valve shaft that moves back and forth by an air cylinder to move in and out of the product molding die surface to open and close the valve seat hole, and a switching valve that controls the supply of air to the valve seat hole and the air cylinder. An injection molding die characterized by the above.