Plunger type exhaust screw

Abstract

The utility model relates to a plunger type exhaust screw, which comprises a screw unit, a plunger unit and a nozzle, the screw unit comprises a material pipe, a screw, a screw head and an exhaust valve, the screw head and the screw are sequentially arranged at the axis of the material pipe, and the exhaust valve is arranged on the side wall of the material pipe; the plunger unit comprises a plunger material pipe and a plunger rod, the plunger material pipe is communicated with the screw head, the plunger rod is movably arranged in the plunger material pipe, and the top of the plunger material pipe is communicated with a nozzle. According to the utility model, through the arrangement of the plunger material pipe, molten materials are firstly injected into the plunger material pipe to be stored, and then the materials are extruded through the plunger rod, so that the extrusion rate and the extrusion amount can be controlled, and the device is suitable for precise injection molding.

Description

Technical Field

[0001] The utility model relates to the technical field of extrusion equipment, in particular to a plunger type exhaust screw. Background Art

[0002] The injection molding machine is an important equipment in the plastic production process. It is a kind of equipment that melts plastic particles and injects them into a specific mold to form a product. At present, most injection molding machines include a screw, a screw head and a nozzle. After the screw is transported and heated, the screw head is exhausted and then ejected from the nozzle. However, this type of screw cannot adjust the extrusion flow rate and contains a large amount of gas (that is, the screw head is not completely exhausted), which is not suitable for precision injection.

[0003] Therefore, there is a need in the art for a venting screw capable of achieving precision injection. Summary of the invention

[0004] The purpose of the utility model is to provide a plunger type exhaust screw in order to overcome the defects of the prior art.

[0005] In order to achieve the purpose of the utility model, the present application provides the following technical solutions.

[0006] In a first aspect, the present application provides a plunger-type exhaust screw, which includes a screw unit, a plunger unit and a nozzle, wherein the screw unit includes a material pipe, a screw, a screw head and an exhaust valve, the screw head and the screw are sequentially arranged at the axis of the material pipe, and the side wall of the material pipe is provided with an exhaust valve; the plunger unit includes a plunger material pipe and a plunger rod, the plunger material pipe is connected to the screw head, the plunger rod is movably arranged in the plunger material pipe, and the top of the plunger material pipe is connected to the nozzle.

[0007] In one implementation of the first aspect, the plunger-type exhaust screw includes a flange connection body, the screw unit and the plunger unit are vertically mounted on the flange connection body, and the nozzle is fixed to the flange connection body via a flange.

[0008] In one embodiment of the first aspect, a material flow channel is provided in the flange connector, one end of the material flow channel is communicated with the screw head, and the other end is communicated with the head of the plunger material pipe, and a one-way valve is provided in the material flow channel.

[0009] In one embodiment of the first aspect, the screw includes a feeding section and a double-screw section arranged in sequence from the rear end to the front end; along the axial feeding direction of the screw, the thread width of the feeding section gradually decreases, the lead gradually increases, and the minor diameter gradually increases, and an exhaust valve is arranged on the material pipe at a position corresponding to the double-screw section.

[0010] In one embodiment of the first aspect, the exhaust valve is detachably mounted on the side wall of the material pipe, the upper and lower ends of the exhaust valve are connected, and the diameter of the exhaust valve at one end close to the material pipe is smaller than the diameter of the end away from the material pipe.

[0011] In one embodiment of the first aspect, the exhaust valve includes a support seat, the bottom of the support seat is fixed to the side wall of the material pipe by bolts, the bottom and top of the support seat are connected, and the top is connected to the atmosphere.

[0012] In an implementation manner of the first aspect, the exhaust valve comprises a cover plate, a side edge of the cover plate is connected to the top of the support seat via a rotating shaft, and a three-way catalytic converter is provided in the center of the cover plate.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] (1) By setting up a plunger material tube, the molten material is first injected into the plunger material tube for storage, and then the material is extruded through the plunger rod, so that the extrusion rate and extrusion amount can be controlled, which is suitable for precision injection molding;

[0015] (2) The structure of the screw ensures that the melt has sufficient exhaust space in the double-screw section, allowing heat radiation to evaporate the water, turning it into water vapor and discharging it from the exhaust valve, which not only improves product quality but also saves energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of the plunger-type exhaust screw of this application;

[0017] Figure 2 This is a schematic diagram of the structure of the exhaust valve of this application.

[0018] In the accompanying drawings, 1 is a screw unit, 2 is a plunger unit, 3 is a material pipe, 4 is a feeding section, 6 is a double-screw section, 8 is a screw head, 9 is an exhaust valve, 10 is a one-way valve, 11 is a plunger material pipe, 12 is a plunger rod, 13 is a flange connector, 14 is a material channel, 15 is a flange, 16 is a nozzle, 17 is a support seat, 18 is a cover plate, 19 is a rotating shaft, 20 is an exhaust channel, 21 is a bolt, 22 is a three-way catalytic converter, and 23 is a handle. DETAILED DESCRIPTION

[0019] Unless otherwise defined, the technical or scientific terms used in this specification and claims shall have the ordinary meanings understood by persons having ordinary skills in the technical field to which the present invention belongs. All the values ​​from the lowest value to the highest value listed herein refer to all the values ​​obtained by incrementing one unit between the lowest value and the highest value when the difference between the lowest value and the highest value is more than two units.

[0020] The specific embodiments of the present invention will be described below in conjunction with the accompanying drawings. It should be noted that in the specific description of these embodiments, for the sake of concise description, this specification cannot provide a detailed description of all the features of the actual embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art may modify and replace the embodiments of the present invention, and the resulting embodiments are also within the scope of protection of the present invention.

[0021] The conventional screw cannot control the extrusion flow rate and is therefore not suitable for precision production. The purpose of the present application is to provide a plunger exhaust screw suitable for precision production.

[0022] In a specific embodiment, the present application provides a plunger-type exhaust screw, which includes a screw unit, a plunger unit and a nozzle, wherein the screw unit includes a material tube, a screw, a screw head and an exhaust valve, the screw head and the screw are sequentially arranged at the axis of the material tube, and the side wall of the material tube is provided with an exhaust valve; the plunger unit includes a plunger material tube and a plunger rod, the plunger material tube is connected to the screw head, the plunger rod is movably arranged in the plunger material tube, and the top of the plunger material tube is connected to the nozzle. The raw material is melted in the screw unit, and under the action of the screw, it is ejected from the screw head and then enters the plunger material tube for storage. When injection molding is required, the plunger rod is pushed forward to extrude the molten raw material from the plunger material tube. Since the forward distance of the plunger is controllable and the diameter of the plunger material tube is uniform, the extrusion amount is also controllable. In addition, since the raw material is stored in the plunger material tube, it can be extruded at any time, and the extrusion can be stopped at any time, and the production is more flexible.

[0023] The raw material melts in the material pipe. When it reaches the exhaust valve, the molten raw material is spread and baked to turn the water into gas and discharge from the exhaust valve. The second stage of secondary compression makes the melt denser and the mixing more uniform. The moisture is discharged again and the water vapor is evaporated by the heat energy of the material pipe. The purpose of dehumidification is achieved by heat radiation and secondary compression of the molten plastic, eliminating the need for drying equipment, saving electricity costs and equipment investment.

[0024] In a specific embodiment, the plunger type exhaust screw includes a flange connection body, the screw unit and the plunger unit are vertically mounted on the flange connection body, and the nozzle is fixed to the flange connection body through a flange. In actual operation, the material pipe of the screw unit is expected to be horizontally mounted on the flange connection body, and the nozzle is also horizontally mounted on the flange connection body, which makes installation faster and more convenient.

[0025] In a specific embodiment, a material passage is provided in the flange connection body, one end of the material passage is connected to the screw head, and the other end is connected to the head of the plunger material tube, and a one-way valve is provided in the material passage. When the plunger rod is pushed forward, the material can be ejected from the nozzle or flow back to the screw unit (or the material passage). In order to avoid backflow, all the raw materials are ejected from the nozzle, thereby controlling the extrusion amount of the raw materials, which needs to be achieved by setting a one-way valve.

[0026] In a specific embodiment, the screw includes a feeding section and a double-screw section arranged in sequence from the rear end to the front end; along the axial feeding direction of the screw, the thread width of the feeding section gradually decreases, the lead gradually increases, and the minor diameter gradually increases, and an exhaust valve is arranged on the material pipe at a position corresponding to the double-screw section. This arrangement can ensure that the pressure of the material gradually increases during the conveying process, so that gas-liquid separation can be achieved at the exhaust valve.

[0027] In a specific embodiment, the exhaust valve is detachably mounted on the side wall of the material pipe, the upper and lower ends of the exhaust valve are connected, and the diameter of the exhaust valve at the end close to the material pipe is smaller than the diameter of the end away from the material pipe. When the melt is transported to the top of the screw, the gas and liquid are basically separated. As long as an outlet is set, the gas can be easily separated from the melt. Therefore, the present application only sets a simple exhaust valve to discharge the gas into the atmosphere. However, in order to avoid the melt being taken out of the conveying pipeline during gas discharge, the present application sets the exhaust valve to a structure with a large upper part and a small lower part, giving the melt a buffer space, so that it adheres to the inner wall of the exhaust valve, and finally flows back into the conveying pipeline under the action of gravity.

[0028] In a specific embodiment, the exhaust valve includes a support seat, the bottom of the support seat is fixed to the side wall of the material pipe by bolts, the bottom and top of the support seat are connected, and the top is connected to the atmosphere.

[0029] In a specific embodiment, the exhaust valve includes a cover plate, one side of the cover plate is connected to the top of the support seat through a rotating shaft, and a three-way catalytic converter is arranged in the center of the cover plate. When the screw is not in use, the melt solidifies and adheres to the exhaust valve. The cover plate is set to an openable and closable structure, which can facilitate the removal of this part of the solidified raw materials to avoid contamination of subsequent products.

[0030] At the same time, when the gas is discharged from the screw to the outside, the air pressure drops sharply from high pressure, and the water vapor will condense to produce white mist. Although the white mist is not too dangerous to people, it is not beautiful for a production workshop to have white mist coming out all the time. Therefore, the utility model adds a three-way catalytic converter in the cover plate. Since the entire exhaust valve is fixedly installed on the conveying pipeline and the exhaust valve is made of metal, the temperature of the entire exhaust valve (including the three-way catalytic converter) is relatively high. When the white mist rises, it contacts the high-temperature three-way catalytic converter and is reheated and vaporized, solving the problem of white mist.

[0031] Example

[0032] The following will describe in detail an embodiment of the present invention in conjunction with the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation method and a specific operation process, but the protection scope of the present invention is not limited to the following embodiment.

[0033] Example 1

[0034] A plunger type exhaust screw, the structure of which is as follows Figure 1 As shown, it includes a screw unit 1, a plunger unit 2, a flange connector 13 and a nozzle 16. During installation, the flange connector 13 is vertically arranged, the screw unit 1 and the plunger unit 2 are horizontally fixed on the flange connector 13, the nozzle 16 is horizontally fixed on the flange connector 13 through the flange 15, and the screw unit 1 is located above the plunger unit 2, and the plunger unit 2, the flange 15 and the nozzle 16 are coaxially arranged.

[0035] The screw unit 1 includes a material pipe 3, a screw and a screw head 8. The front end of the material pipe 3 is fixed to the flange connector 13. The screw head 8 and the screw are arranged at the axis of the material pipe 3 in sequence. The feeding section 4 and the double-screw section 6 are arranged in sequence from the rear end to the front end of the screw. The screw, the screw head 8 and the material pipe 3 used in this embodiment are all prior art. An exhaust valve 9 is provided on the top side wall of the material pipe 3, corresponding to the position of the double-screw section 6. The structure of the exhaust valve 9 is as follows: Figure 2 shown.

[0036] The exhaust valve 9 includes a support seat 17 and a cover plate 18 fixed on the support seat 17 by a rotating shaft 19, wherein the center of the support seat 17 is connected at both ends, and an exhaust passage 20 with a small bottom and a large top is formed. The bottom of the support seat 17 is fixed to the side wall of the material pipe 3 by bolts 21. The center of the cover plate 18 is also hollow, and at least one layer of three-way catalytic converter 22 is arranged therein, and a handle 23 is arranged on the other side of the cover plate 18. When the material is melted and transported to the double screw section 6, an exhaust valve 9 is arranged on the material pipe 3, and the gas and liquid are separated, and the gas is directly discharged from the exhaust valve 9. A small amount of melt ejected upward with the gas settles in the exhaust passage 20 and flows back into the material pipe 3. The rising gas is heated by the high-temperature three-way catalytic converter 22 and discharged into the atmosphere to avoid the generation of white fog.

[0037] The flange connector 13 is provided with a through material channel 14, the material outlet of the screw head 8 is connected to the upper end of the material channel 14, and a one-way valve 10 is provided near the connection. The lower end of the material channel 14 is connected to the front end of the plunger material pipe 11.

[0038] The plunger unit 2 includes a plunger material tube 11 and a plunger rod 12 installed in the plunger material tube 11. The front end of the plunger material tube 11 is horizontally fixed on the flange connector 13, and two material ports, one inlet and one outlet, are provided at the top of the plunger material tube 11. The material inlet is connected to the lower end of the material passage 14, and the material outlet is coaxially arranged and connected to the flange 15 and the nozzle 16. A heating unit can be provided in the plunger material tube 11 or on the side wall of the plunger material tube 11 to keep the material stored in the plunger material tube 11 in a molten state at all times.

[0039] The above description of the embodiments is to facilitate those of ordinary skill in the art to understand and apply the present application. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without having to pay creative labor. Therefore, the present application is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the contents disclosed in the present application without departing from the scope and spirit of the present application are within the scope of the present application.

Claims

1. A plunger type exhaust screw, characterized in that: The plunger-type exhaust screw comprises a screw unit, a plunger unit and a nozzle, wherein: The screw unit comprises a material pipe, a screw, a screw head and an exhaust valve, wherein the screw head and the screw are sequentially arranged at the axis of the material pipe, and the side wall of the material pipe is provided with an exhaust valve; The plunger unit comprises a plunger material tube and a plunger rod. The plunger material tube is communicated with the screw head. The plunger rod is movably arranged in the plunger material tube. The top of the plunger material tube is communicated with the nozzle.

2. The plunger type exhaust screw according to claim 1, characterized in that: The plunger-type exhaust screw comprises a flange connection body, the screw unit and the plunger unit are vertically mounted on the flange connection body, and the nozzle is fixed to the flange connection body through a flange.

3. The plunger type exhaust screw according to claim 2, characterized in that: A material flow channel is provided in the flange connection body, one end of the material flow channel is communicated with the screw head, and the other end is communicated with the head of the plunger material pipe, and a one-way valve is provided in the material flow channel.

4. The plunger type exhaust screw according to claim 1, characterized in that: The screw includes a feeding section and a double-screw section arranged in sequence from the rear end to the front end; along the axial feeding direction of the screw, the thread width of the feeding section gradually decreases, the lead gradually increases, and the minor diameter gradually increases, and an exhaust valve is arranged on the material pipe at a position corresponding to the double-screw section.

5. The plunger type exhaust screw according to claim 4, characterized in that: The exhaust valve is detachably mounted on the side wall of the material pipe, the upper and lower ends of the exhaust valve are connected, and the diameter of the exhaust valve at one end close to the material pipe is smaller than the diameter of the end far from the material pipe.

6. The plunger type exhaust screw according to claim 5, characterized in that: The exhaust valve comprises a support seat, the bottom of which is fixed to the side wall of the material pipe by bolts, the bottom and top of the support seat are connected, and the top is connected to the atmosphere.

7. The plunger type exhaust screw according to claim 6, characterized in that: The exhaust valve comprises a cover plate, one side of which is connected to the top of the support seat via a rotating shaft, and a three-way catalytic converter is arranged in the center of the cover plate.

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