Vacuum-pumping valve needle structure of mold cavity

Abstract

The utility model relates to the field of plastic part injection molding, in particular to a mold cavity vacuumizing valve needle structure which comprises an air guide pipe and a vacuum valve needle, one end of the air guide pipe is fixedly connected with a mounting seat, an air inlet port of the other end of the air guide pipe is inserted into a vacuum channel of a mold, and a sealing piece used for sealing a port of the vacuum channel is fixed on the outer side of the air guide pipe. The vacuum valve needle is installed in the air guide pipe in a sliding mode, an air guide gap allowing air to pass through is formed between the vacuum valve needle and the air guide pipe, and the vacuum valve needle is driven by a driving piece in the installation base to move and used for sealing an air inlet end opening of the air guide pipe. Due to the fact that the interior of the mold cavity is in the vacuum state, the problems that gas in the cavity generates pressure to prevent colloid from flowing, the surface of the plastic part is scorched, and the apparent quality of a product is affected are solved.

Description

Technical Field

[0001] The utility model relates to the field of plastic parts injection molding, and specifically is a mold cavity vacuum valve needle structure. Background Technology

[0002] During the injection molding process, the molten plastic material in the screw of the injection molding machine needs to be injected into the mold under high pressure and cooled to form a plastic part.

[0003] Since the injection time into the mold cavity is very short (usually completed within 1 to 4 seconds), the colloid injected into the cavity will instantly squeeze the air in the cavity to the end or the air trapping point during the inflow process, which will cause the gas in the cavity that has not been discharged through the mold exhaust structure in time to generate high pressure and high heat, causing the surface of the plastic part to be scorched, affecting the apparent quality of the product. Contents of utility model

[0004] The purpose of the utility model is to provide a mold cavity vacuum valve needle structure, which is used to solve the problem that during the existing injection molding, the colloid injected into the cavity at high speed will instantly squeeze the air in the cavity during the inflow process to generate high pressure and high heat, causing the surface of the plastic part to be scorched, affecting the apparent quality of the product.

[0005] To achieve the above purpose, the utility model provides a mold cavity vacuum valve needle structure, including an air guide tube and a vacuum valve needle, one end of the air guide tube is fixedly connected to the mounting seat, and the air inlet port at the other end is inserted into the vacuum channel of the mold, a sealing member for sealing the vacuum channel port is fixed to the outside of the air guide tube, the vacuum valve needle is slidably installed in the air guide tube, and an air guide gap for gas to pass through is provided between the vacuum valve needle and the air guide tube, and the vacuum valve needle is driven to move by a driving member in the mounting seat to seal the air inlet port of the air guide tube.

[0006] As a further solution of the utility model, the sealing member is a sealing cover, and the sealing cover seals the port inserted into the vacuum channel.

[0007] As a further solution of the utility model, the mounting seat is provided with a vacuum air path interface for connecting to the inside of the airway tube, and the vacuum air path interface is used to connect to the negative pressure suction equipment.

[0008] As a further solution of the utility model, the driving member is a driving oil cylinder, and the movable plug rod of the driving oil cylinder is drivingly connected to the end of the vacuum valve needle.

[0009] Compared with the prior art, the utility model designs an air guide pipe and a vacuum valve needle. The air inlet port of the air guide pipe is inserted into the vacuum channel of the mold. At the same time, the vacuum valve needle is slidably installed in the air guide pipe and is driven by a driving oil cylinder to move to seal the air inlet port of the air guide pipe, avoiding the generation of gas pressure in the cavity to prevent the colloid from flowing, and forming a charred phenomenon on the surface of this part of the plastic part, which affects the apparent quality of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic structural diagram of a vacuum valve needle structure for evacuating a mold cavity in the utility model.

[0011] In the drawings: 1, mold; 2, product cavity; 3, sealing cover; 4, air guide pipe; 5, vacuum valve needle; 6, air guide gap; 7, vacuum air path interface; 8, mounting seat; 9, driving oil cylinder. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0012] The technical solutions of the present utility model will be further described in detail below in conjunction with the specific embodiments.

[0013] As Figure 1 shown, in the embodiment of the present utility model, a vacuum valve needle structure for evacuating a mold cavity includes an air guide pipe 4 and a vacuum valve needle 5. One end of the air guide pipe 4 is fixedly connected to a mounting seat 8, and the other end air inlet port is inserted into the vacuum channel of the mold 1. A sealing member for sealing the port of the vacuum channel is fixed on the outer side of the air guide pipe 4. The vacuum valve needle 5 is slidably installed in the air guide pipe 4. An air guide gap 6 for gas to pass through is provided between the vacuum valve needle 5 and the air guide pipe 4. The vacuum valve needle 5 is driven by a driving member in the mounting seat 8 to move for sealing the air inlet port of the air guide pipe 4;

[0014] Specifically, when the present invention is in use:

[0015] Drive the vacuum valve needle 5 to move so that an air guide gap 6 for gas to pass through is provided between the vacuum valve needle 5 and the air guide pipe 4 and is communicated with the product cavity 2. Evacuate the product cavity 2 of the mold 1 through a negative pressure suction device to obtain a product cavity 2 in a vacuum state. Reset the vacuum valve needle 5 to keep the product cavity 2 in a vacuum state. At this time, the hot runner needle valve gate can be opened, and the colloid is injected into the cavity of the mold 1. Since the cavity of the mold 1 is in a vacuum state, this avoids the generation of gas pressure in the cavity to prevent the colloid from flowing.

[0016] As Figure 1 shown, in the embodiment of the present utility model, the sealing member is a sealing cover 3. The sealing cover 3 is hermetically inserted at the port of the vacuum channel. Of course, in practice, other components with negative pressure sealing ability can also be selected, such as a negative pressure sealing ring.

[0017] AsFigure 1 As shown, in the embodiment of the present utility model, a vacuum air path interface 7 for connecting to the inside of the air guide pipe 4 is provided on the mounting base 8. The vacuum air path interface 7 is used to connect to a negative pressure suction device, and the negative pressure suction device includes components such as a negative pressure pump and a negative pressure gas cylinder.

[0018] As Figure 1 shown, in the embodiment of the present utility model, the driving member is a driving oil cylinder 9. The movable piston rod of the driving oil cylinder 9 is in transmission connection with the end of the vacuum valve needle 5. The driving oil cylinder 9 drives the movable piston rod to expand and contract, driving the vacuum valve needle 5 to reciprocate, to seal or open the air inlet end of the vacuum valve needle 5.

[0019] In summary, by designing the air guide pipe 4 and the vacuum valve needle 5, the air inlet port of the air guide pipe 4 is inserted into the vacuum channel of the mold 1. At the same time, the vacuum valve needle 5 is slidably installed in the air guide pipe 4, and is driven by the driving oil cylinder 9 to move to seal the air inlet port of the air guide pipe 4, avoiding the problem that gas generates pressure in the cavity to prevent the colloid from flowing, resulting in a charred phenomenon on the surface of this part of the plastic part and affecting the appearance quality of the product.

[0020] The above has described the preferred embodiments of the present utility model in detail, but the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the purpose of the present utility model.

Claims

1. A mold cavity vacuum valve needle structure, characterized in that: It includes an air guide tube and a vacuum valve needle. One end of the air guide tube is fixedly connected to the mounting seat, and the air inlet port at the other end is inserted into the vacuum channel of the mold. A sealing member for sealing the vacuum channel port is fixed to the outside of the air guide tube. The vacuum valve needle is slidably installed in the air guide tube. An air guide gap for gas to pass through is provided between the vacuum valve needle and the air guide tube. The vacuum valve needle is driven to move by a driving member in the mounting seat to seal the air inlet port of the air guide tube.

2. A mold cavity vacuum valve needle structure according to claim 1, characterized in that: The sealing member is a sealing cover, and the sealing cover seals the port inserted into the vacuum channel.

3. The mold cavity vacuum valve needle structure according to claim 1, characterized in that: The mounting seat is provided with a vacuum air path interface for connecting to the inside of the air duct, and the vacuum air path interface is used to connect to the negative pressure suction equipment.

4. The mold cavity vacuum valve needle structure according to claim 3, characterized in that: The driving member is a driving oil cylinder, and the movable plug rod of the driving oil cylinder is drivingly connected to the end of the vacuum valve needle.

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