Hollow screw
The hollow screw design with integrated gas-liquid separation effectively addresses the cost issue of existing gas discharge methods by directly discharging gas into the atmosphere, reducing equipment costs and maintaining product quality.
Patent Information
- Application Number
- CN202421076646.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-17
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2034-05-17
AI Technical Summary
Existing methods for discharging gas from plastic injection molding machines are costly due to the need for a gas-liquid separation valve, which increases equipment expenses.
A hollow screw design with a hollow axis and integrated gas-liquid separation unit, featuring air outlets and exhaust channels, allows gas to be discharged directly into the atmosphere without the need for additional valves.
This design effectively separates gas from melt at a lower cost by eliminating the requirement for a separate gas-liquid separation valve, ensuring high-quality product production.
Smart Images
Figure CN222271162U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of injection molding accessories, in particular to a hollow screw. Background Art
[0002] The plastic raw material is plasticized into a uniform melt through the extrusion system, and under the pressure established in this process, the material is continuously injected into the molding head by the screw. Therefore, the screw is one of the key components of the main extrusion system of the plastic injection molding machine. Since the raw material is added to the injection molding machine as solid particles, it will inevitably be mixed with gas after the raw material is melted. This part of the gas must be discharged before extrusion to avoid affecting the product quality. At present, the main way to discharge this part of the gas is to open a gas-liquid separation valve on the shell of the injection molding machine so that the gas can pass through but the melt cannot pass through, but this method is relatively expensive. Summary of the invention
[0003] The purpose of the utility model is to provide a hollow screw in order to overcome the defects of the prior art, which can realize the separation of gas and melt at a relatively low cost.
[0004] In order to achieve the purpose of the utility model, the present application provides the following technical solutions.
[0005] In the first aspect, the present application provides a hollow screw, the axis of which is a hollow structure, the screw comprising a conveying end and a light edge end, the light edge end being provided with an air outlet, the air outlet being connected to the screw exhaust hole of the screw, the top end of the conveying end being coaxially fixed with a screw head, the screw head being provided with a gas-liquid separation unit, the gas-liquid separation unit being connected to the screw exhaust hole of the screw.
[0006] In one implementation of the first aspect, the axis of the screw is a hollow structure from the top to the tail, and an air outlet is provided at the axis of the tail end surface of the light edge end.
[0007] In one implementation of the first aspect, the side wall of the light edge end is provided with an air outlet, and the side wall of the light edge end is provided with an exhaust channel perpendicular to the axis, and the exhaust channel connects the screw exhaust hole and the atmosphere.
[0008] In one embodiment of the first aspect, the rear end axis of the screw head is a hollow structure, the gas-liquid separation unit includes multiple groups of exhaust units, each group of exhaust units includes a first ring sheet and a second ring sheet, the first ring sheet and the second ring sheet are sleeved on the screw head, and at least one exhaust gap is provided between the first ring sheet and the second ring sheet, and the exhaust gap is connected to the rear end axis of the screw head.
[0009] In one embodiment of the first aspect, the tail end of the screw head is provided with a connecting portion, the outer wall of the connecting portion is provided with an external thread, the top axis of the screw is provided with an internal thread matching the external thread, and when the screw head is fixed to the top end of the screw, the top end face of the screw abuts against and applies pressure to the tail end face of the gas-liquid separation unit.
[0010] In one implementation of the first aspect, a feed port is between the conveying end and the light edge end.
[0011] In one embodiment of the first aspect, the conveying end of the screw includes a feeding section, an extrusion section and a metering section in sequence from the tail end to the top end. Along the axial feeding direction of the screw, the screw thread width, lead and minor diameter of the feeding section remain uniform, the screw thread lead and minor diameter of the extrusion section gradually increase, and the screw thread width, lead and minor diameter of the metering section remain uniform.
[0012] Compared with the prior art, the utility model has the beneficial effect that by setting the axis of the screw to a hollow structure, air can be discharged from the axis of the screw to the atmosphere, thereby reducing the setting of the gas-liquid separation valve and reducing the cost of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a schematic diagram of the structure of the hollow screw in Example 1;
[0014] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure of AA;
[0015] Figure 3 It is a structural schematic diagram of the screw head;
[0016] Figure 4 It is a schematic diagram of the cross-sectional structure of the exhaust part of the screw head;
[0017] Figure 5 is a front view of the first ring piece;
[0018] Figure 6 is a front view of the second ring piece;
[0019] Figure 7 It is a schematic diagram of the structure after the screw head is installed on the top of the screw;
[0020] Figure 8 Schematic diagram of the structure of the hollow screw in Example 2;
[0021] Fig. 9 This is a schematic diagram of the end face of the tail end of the hollow screw in Example 2.
[0022] In the accompanying drawings, 1 is the conveying end, 2 is the light edge end, 3 is the feed port, 4 is the screw exhaust hole, 5 is the exhaust channel, 6 is the metering section, 7 is the extrusion section, 8 is the feeding section, 9 is the screw head, 10 is the exhaust part, 11 is the meson, 12 is the connecting part, 13 is the first ring piece, 14 is the second ring piece, 15 is the screw head axis, 16 is the exhaust groove, 17 is the connecting channel, 18 is the exhaust gap, 19 is the tooth, and 20 is the air groove. DETAILED DESCRIPTION
[0023] 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.
[0024] 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.
[0025] In a specific embodiment, a hollow screw is provided, wherein the axis of the screw is a hollow structure, the screw comprises a conveying end and a light edge end, the light edge end is provided with an air outlet, the air outlet is communicated with the screw exhaust hole of the screw, the top end of the conveying end is coaxially fixed with a screw head, the screw head is provided with a gas-liquid separation unit, and the gas-liquid separation unit is communicated with the screw exhaust hole of the screw. The present application achieves gas-liquid separation by setting the axis of the screw to be hollow, and then discharging the gas in the melt toward the axis of the screw and finally discharging it into the atmosphere, thereby avoiding the additional setting of a gas-liquid separation valve and saving costs.
[0026] A preferred arrangement of the air outlet is that the axis of the screw is a hollow structure from the top to the tail, and the air outlet is arranged at the axis of the tail end face of the light edge end.
[0027] Another preferred air outlet arrangement is that the side wall of the light edge end is provided with an air outlet, and the side wall of the light edge end is provided with an exhaust channel perpendicular to the axis, and the exhaust channel connects the screw exhaust hole and the atmosphere. Both of the above-mentioned air outlets can be provided with a one-way valve to prevent air from entering the screw in the reverse direction.
[0028] In a specific embodiment, the rear end axis of the screw head is a hollow structure, and the gas-liquid separation unit includes multiple exhaust units, each exhaust unit includes a first ring sheet and a second ring sheet, the first ring sheet and the second ring sheet are sleeved on the screw head, and at least one exhaust gap is provided between the first ring sheet and the second ring sheet, and the exhaust gap is connected to the rear end axis of the screw head. This is a preferred exhaust method, by setting an exhaust gap with a smaller depth, generally 0.001mm to 0.1mm, due to the high viscosity of the melt, the melt cannot pass through these exhaust gaps, but the gas mixed in the melt can, therefore, the gas finally enters the exhaust hole of the screw through the exhaust gap, and then is discharged to achieve gas-liquid separation.
[0029] In a specific embodiment, the tail end of the screw head is provided with a connection part, the outer wall of the connection part is provided with an external thread, the top axis of the screw is provided with an internal thread matching the external thread, and when the screw head is fixed to the top end of the screw, the top end face of the screw abuts against and applies pressure to the tail end face of the gas-liquid separation unit. A meson is provided on the screw head, and the two ends of the gas-liquid separation unit are clamped by the meson and the screw respectively, so as to ensure that the gas can only enter from the exhaust gap, and also prevent the melt from entering the axis from other gaps, thereby blocking the axis.
[0030] In a specific embodiment, a feed port is located between the conveying end and the light edge end.
[0031] In a specific embodiment, the conveying end of the screw includes a feeding section, an extrusion section and a metering section from the tail end to the top end, and along the axial feeding direction of the screw, the thread width, lead and minor diameter of the feeding section remain uniform, the thread lead and minor diameter of the extrusion section gradually increase, and the thread width, lead and minor diameter of the metering section remain uniform. Such an arrangement can make the solid material gradually melt in the process of advancing, and the pressure gradually increases, so that the melt has sufficient pressure when it reaches the screw head, prompting the gas to enter the exhaust gap to achieve gas-liquid separation.
[0032] Example
[0033] 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.
[0034] Example 1
[0035] A hollow screw having a structure as follows Figure 1As shown, it includes a conveying end on the left and a light edge end 2 on the right, with a feed port 3 arranged between the two. The conveying end includes a feeding section 8, an extrusion section 7 and a metering section 6 from the tail end to the top end in sequence. Along the axial feeding direction of the screw, the thread width, lead and minor diameter of the feeding section 8 remain uniform, the thread lead and minor diameter of the extrusion section 7 gradually increase, and the thread width, lead and minor diameter of the metering section 6 remain uniform. In this embodiment, a screw exhaust hole 4 is provided at the axis of the screw, but it does not penetrate the entire screw. Four exhaust channels 5 are opened on the side wall of the light edge end 2, as shown in FIG. Figure 2 As shown, the exhaust channel 5 connects the screw exhaust hole 4 and the atmosphere. An internal thread portion is provided at the top axis of the screw, which matches the external thread outside the connecting portion 12 of the screw head 9, and the screw exhaust hole 4 of the screw is connected to the gas-liquid separation unit of the screw head 9.
[0036] The structure of the screw head 9 is as follows Figure 3 to Figure 6 As shown, a meson 11, an exhaust portion 10 and a connecting portion 12 are sequentially arranged at the tail end thereof, wherein the screw head axis 15 corresponding to the exhaust portion 10 and the connecting portion 12 is a hollow structure, and four exhaust grooves 16 are arranged on the outer surface of the exhaust portion 10, as shown in FIG. Figure 4 As shown, the exhaust grooves 16 are distributed along the axial direction of the exhaust section 10. Four exhaust channels 5 are connected to the exhaust channel 17 on the exhaust section 10. Each exhaust groove 16 is connected to the screw head axis 15 through a connecting channel 17, and the screw head axis 15 is connected to the screw exhaust hole 4 of the screw. A gas-liquid separation unit is arranged outside the exhaust section 10. The gas-liquid separation unit is composed of 8 groups of exhaust units. Each group of exhaust units includes a first ring sheet 13 and a second ring sheet 14. The structure of the first ring sheet 13 is as shown in FIG. Figure 5 As shown, the structure of the second ring piece 14 is as follows Figure 6 As shown, the inner hole diameters of the first ring piece 13 and the second ring piece 14 match the outer diameter of the exhaust portion 10. Four exhaust gaps 18 are provided on one side of the first ring piece 13. The depth of the exhaust gap 18 is 0.01 mm. The inner side of each exhaust gap 18 is connected to the exhaust groove 16. The other side of the first ring piece 13 is smooth and flat. The two side surfaces of the second ring piece 14 are smooth and flat. The first ring piece 13 and the second ring piece 14 are alternately abutted in sequence. The first ring piece 13 is closest to the meson 11 and is in close contact with the smooth and flat side of the first ring piece 13. The second ring piece 14 is closest to the screw. The outer ring of the second ring piece 14 is provided with evenly distributed teeth 19. The gas-liquid separation unit is clamped by the meson 11 and the top end of the screw, as shown in FIG. Figure 7 shown.
[0037] During operation, solid materials are added from the feed port 3 and transported to the top along with the screw. During the transportation process, the solid materials melt and mix with the air. The molten colloid with gas flows from right to left along with the screw. The pressure of the molten colloid gradually increases. When it flows to the exhaust part 10, the pressure of the colloid is relatively high, and the gas can enter the gas-liquid separation unit from the exhaust gap 18, and finally gather in the exhaust groove 16, and then reach the screw head axis 15 through the connecting channel 17, and then enter the screw exhaust hole 4, and finally be discharged into the air through the exhaust channel 5. Due to the small depth of the exhaust gap 18, the colloid cannot enter the exhaust gap 18, and can only continue to move forward and be squeezed out, so that the gas and liquid are separated, and the colloid (liquid) is squeezed out of the nozzle to form a product, and there will be no residual air in the product.
[0038] Example 2
[0039] A hollow screw similar to that of Example 1 is used, except that the exhaust hole 4 of the screw of this embodiment runs through the entire screw, and a groove connecting the center to the atmosphere is provided on the end face of the screw tail end, and the air is directly discharged from the tail end of the screw to the atmosphere through an air groove 20. Figure 8 , Fig. 9 The gas reaches the end face of the tail end from the exhaust hole 4 of the screw, and then is discharged to the atmosphere from the gas groove 20 (because the tail end of the screw is generally in contact with the propulsion unit, the gas groove 20 needs to be provided to discharge the gas to the atmosphere).
[0040] 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 hollow screw, characterized in that: The axis of the screw is a hollow structure, and the screw includes a conveying end and a light edge end. The light edge end is provided with an air outlet, and the air outlet is connected to the screw exhaust hole of the screw. The top end of the conveying end is coaxially fixed with a screw head, and a gas-liquid separation unit is provided on the screw head, and the gas-liquid separation unit is connected to the screw exhaust hole of the screw.
2. The hollow screw according to claim 1, characterized in that The axis of the screw is a hollow structure from the top to the tail, and an air outlet is arranged at the axis of the tail end surface of the light edge end.
3. The hollow screw according to claim 1, characterized in that The side wall of the light edge end is provided with an air outlet, and the side wall of the light edge end is provided with an exhaust channel perpendicular to the axis, and the exhaust channel is connected with the exhaust hole of the screw and the atmosphere.
4. The hollow screw according to claim 1, characterized in that: The rear end axis of the screw head is a hollow structure, and the gas-liquid separation unit includes multiple groups of exhaust units, each group of exhaust units includes a first ring sheet and a second ring sheet, the first ring sheet and the second ring sheet are sleeved on the screw head, and at least one exhaust gap is provided between the first ring sheet and the second ring sheet, and the exhaust gap is connected to the rear end axis of the screw head.
5. The hollow screw according to claim 4, characterized in that The tail end of the screw head is provided with a connecting portion, the outer wall of the connecting portion is provided with an external thread, the top axis of the screw is provided with an internal thread matching the external thread, and when the screw head is fixed to the top end of the screw, the top end face of the screw abuts against and applies pressure to the tail end face of the gas-liquid separation unit.
6. The hollow screw according to claim 1, characterized in that: A feed inlet is located between the conveying end and the light edge end.
7. The hollow screw according to claim 1, characterized in that The conveying end of the screw includes a feeding section, an extrusion section and a metering section in sequence from the tail end to the top end. Along the axial feeding direction of the screw, the thread width, lead and minor diameter of the feeding section remain uniform, the thread lead and minor diameter of the extrusion section gradually increase, and the thread width, lead and minor diameter of the metering section remain uniform.