JP3005255U - Injection mold with degassing mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose of the present invention is to eliminate the influence of high-pressure gas generated from the molten resin on the cooling water passage when a joint exists in the injection route of the molten resin. [Structure] The high temperature molten resin injected into the gate sprue 15 reaches the gate 16, the flow of the molten resin is restricted near the gate 16, and the cavity for forming the molded article 1 is filled with high pressure. It At this time, the gas generated from the molten resin before the gate is blocked in the vicinity of the gate to seek an escape area, and travels in the direction opposite to the flow of the molten resin to reach the degassing groove 21. The high-pressure gas that has arrived is exhausted to the outside of the mold through the gas vent hole 22 by the suction of the gas suction device so that it does not proceed to other places in the mold from there.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an injection mold having a degassing mechanism.

[0002]

[Prior art]

 Conventionally, as a mold degassing device, for example, a mold decompression device disclosed in Japanese Patent Laid-Open No. 61-33750 can be cited. This mold depressurizing device is a device for injecting compressed air through a conduit to an exhaust port of an exhaust passage communicating with a cavity to cause a depressurizing action to forcibly exhaust gas in a cavity.

[0003]

[Problems to be solved by the device]

 However, although the mold depressurizer described above forcibly exhausts the gas in the cavity, it is considered difficult to forcibly exhaust the high-pressure gas generated until the molten resin reaches the gate. Therefore, in the case of a mold that has a joint due to an insert in the path of the molten resin until it reaches the gate, high-pressure gas advances to the connecting surface between the main body and the insert, and inside the insert. The seal material provided at the joint of the supplied cooling water passage may be deformed or shrunk, and eventually leakage of cooling water may occur. In consideration of such a point, the present invention intends to prevent the high-pressure gas generated from the molten resin from diffusing and prevent the leakage of cooling water.

[0004]

[Means for Solving the Problems]

 Therefore, the injection mold equipped with the degassing mechanism of the present invention is as follows. The fixed die is provided with an insert having a main plate having a runner forming a part thereof and a gate sprue also forming a part of the fixed plate and connecting to the runner. A gas vent groove is formed around the gate sprue on the mating surface of the main plate and the insert, and the gas vent groove is communicated with the gas suction device through the gas vent hole. In the injection molding die equipped with the degassing mechanism described in Section 2.1, cooling water passages are provided in both the insert and the main plate, and they are connected at the joint between the main plate and the insert.

[0005]

[Action]

 The injected molten resin reaches the gate through the runner and gate sprue, the flow of the molten resin is restricted near the gate, and the cavity is filled with high pressure. At this time, the gas generated from the molten resin in front of the gate is blocked near the gate, and an escape area is required at the joint between the main plate and the nest, but it is formed around the gate sprue. From the gas vent groove, through the gas vent hole, it is exhausted to the outside of the mold by the gas suction device.

[0006]

【Example】

 In the figure, 10 is a fixed type and 40 is a movable type. Reference numeral 1 denotes a molded product molded by the fixed mold 10 and the movable mold 40. The fixed mold 10 includes a main plate 11 that is movable in a mold opening direction up to a certain distance, an insert 12 that is fixed to the main plate 11 and forms a bottom cavity space of the molded product 1, and a main plate 11 around the insert 12. It has a block 13 which is fixed and forms a side surface cavity space of the molded product 1. The main plate 11 has a runner 14 connected to a nozzle of a molding machine, the insert 12 has a gate sprue 15, one end of the gate sprue 15 is a runner 14 and the other end is a molded product 1. Communicates with the gate 16 which is in contact with the cavity space. The gate sprue-15 has a large diameter on the side in contact with the runner-14, and has a shape that gradually narrows toward the gate 16.

Next, the degassing mechanism of the injection molding die will be described. Reference numeral 21 is a ring-shaped gas vent groove provided around the gate sprue 15 on the mating surface between the main plate 11 and the insert 12, and 22 is a gas vent hole provided in the main plate 11. One end of the gas vent hole 22 is It communicates with the gas vent groove 21, the other end extends to the side surface of the mold (the surface parallel to the mold opening direction), and is connected to a gas suction device (not shown) via a joint.

Further, the cooling mechanism of the injection molding die will be described. Reference numeral 31 is a cooling hole provided in the vicinity of the gate sprue 15 of the insert 12, which is a mating surface between the main plate 11 and the insert 12 and communicates with a second cooling water passage 34, which will be described later, to adjust the temperature of the injection molding die. Work. A cooling pipe 32 is inserted into the cooling hole 31. One end of the cooling pipe communicates with a first cooling water passage 33, which will be described later, and the other end enters the inside of the cooling hole 31. The supplied cooling water is guided into the cooling hole 31. The first and second cooling water passages 33, 34 are formed in parallel with each other on the main plate 11, one end of each of which opens to the side surface of the mold and is connected to a cooling water supply / discharge device (not shown) through a joint. The other end of the first cooling water passage 33 communicates with the cooling pipe 32, and the other end of the second cooling water passage 34 opens at the mating surface between the main plate 11 and the insert 12 at a position communicating with the cooling hole 31. In this way, the cooling water circulates through the first cooling water passage 33, the cooling pipe 32, the cooling hole 31, and the second cooling water passage 34. Reference numeral 35 denotes an O-ring provided around the opening on the insert side of the second cooling water passage 34 and fitted in a ring-shaped groove portion. It should be sealed to prevent leakage.

The operation of this embodiment having such a configuration is as follows. High temperature molten resin is injected under high pressure to the gate sprue-15. The injected molten resin reaches the gate 16, the flow of the molten resin is restricted near the gate 16, and the cavity for forming the molded product 1 is filled with high pressure. At this time, the gas generated from the molten resin before the gate is blocked in the vicinity of the gate to seek an escape area, and travels in the direction opposite to the flow of the molten resin to reach the degassing groove 21. The high-pressure gas that has reached the gas suction port (not shown) is prevented from advancing to other places in the mold, such as the insertion part of the O-ring 35 and the joint between the cooling hole 31 and the second cooling water passage 34. By the suction of the machine, it is exhausted to the outside of the mold through the gas vent hole 22.

[0010]

[Effect of device]

 According to the present invention, when there is a joint due to a nest or the like in the injection path of the molten resin, the high-pressure gas generated from the molten resin is supplied to the outside of the mold from the gas vent groove provided around the joint. Since high pressure gas is not exhausted at the joints that exist in the middle of the cooling water passage, the leakage of cooling water can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of an injection mold having a degassing mechanism of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molded product 10 Fixed type 11 Main plate 12 Nesting 14 Runner 15 Gate sprue 21 Gas vent groove 22 Gas vent hole 31 Cooling hole 33 First cooling water passage 34 Second cooling water passage 40 Mobile type

Claims (2)

[Scope of utility model registration request] 1. An injection molding die having a degassing mechanism having the following configuration. a. Fixed type. b. Mobile type. c. A main plate that constitutes a part of the fixed mold and is equipped with a runner. d. An insert having a gate sprue that also constitutes a part of the fixed type and is connected to the runner. e. A gas vent groove formed on the mating surface of the main plate and the insert and around the gate sprue. f. A gas vent hole communicating with the gas vent groove. g. A gas suction device connected to the gas vent hole. 2. A cooling water passage is provided in both the insert and the main plate,
The injection molding die having the degassing mechanism according to claim 1, wherein the main plate and the insert are connected to each other at a joint.