Extrusion type screw heating coating head

Abstract

The utility model discloses an extrusion type screw rod heating coating head which comprises an upper die, a lower die and a gasket, wherein the upper die and the lower die are matched with each other; the gasket is arranged between the upper die and the lower die; wherein the upper die is provided with a micrometer flow equalizing adjusting mechanism, the lower die is provided with a material cavity and a slurry inlet communicated with the material cavity, a die seam and a slurry outlet are formed between the upper die and the lower die, and the slurry outlet is communicated with the material cavity through the die seam; heating assemblies are arranged in the upper mold and the lower mold; a two-way screw rod is arranged in a material cavity of the lower die; the spiral directions of the two sections of spiral grooves on the two-way screw rod from the middle to the two sides are opposite; a motor is fixedly installed on the outer side wall of the lower die, and the driving end of the motor is connected with the two-way screw. The slurry is continuously stirred by the two-way screw to provide power so as to be conveyed to the two ends of the material cavity, meanwhile, the slurry is heated by the heating assembly so as to improve the fluidity, the viscosity of the slurry can be reduced, the fluidity of the slurry is improved, and the problem that the high-viscosity slurry is not easy to coat is solved.

Description

Technical Field

[0001] This utility model belongs to the field of lithium-ion battery extrusion coating technology, specifically relating to an extrusion coating head with heating function and screw-assisted circulation function. Background Technology

[0002] With the development of lithium-ion batteries, higher viscosity slurries are required for use in coating processes. High-viscosity slurries are non-Newtonian fluids with extremely high viscosity and poor flowability. When using traditional extrusion coating heads, the pressure loss along the slurry path is large, resulting in unstable and uneven lateral flow velocity and flow rate at the slurry outlet (i.e., coating port), making it difficult to ensure uniform and stable coating.

[0003] To address the aforementioned problems in the industry, the applicant has designed two novel extrusion coating heads: The first is an extrusion coating head with a heating function. It utilizes the fluid characteristic of high-viscosity slurries to thin upon heating. By adding a heating component, the viscosity of the slurry is reduced and its flowability improved. This structure was filed for a utility model patent on October 11, 2023, with patent application number "202322723543.3". The second is an extrusion coating head with an internal circulation function. It utilizes the fluid characteristic of high-viscosity slurries to thin upon shearing. By adding a cam rotor pump, the slurry circulates within the material chamber, generating a shearing effect that reduces the viscosity and improves the flowability. This structure was also filed for a utility model patent on October 11, 2023, with patent application number "202322723451.5".

[0004] However, both of these extrusion coating heads have certain problems in practical applications, as follows:

[0005] Regarding extrusion coating heads with heating function, since they only improve the fluidity of the slurry through heating, the upper limit of improvement is relatively low. They can ensure the uniformity and stability of coating to a certain extent, but they cannot achieve outstanding levels and it is difficult to complete coating processes with high standards.

[0006] Regarding the extrusion coating head with internal circulation function, it requires an external cam rotor pump and matching pipelines, which takes up a large area, has a high manufacturing cost, and takes a long time for initial installation and subsequent maintenance. In addition, it is necessary to purge the gas in the pipeline before operation to circulate the slurry, making the control cumbersome and complicated. Utility Model Content

[0007] This invention provides an extrusion screw heating coating head, which aims to solve the problem of high-viscosity slurry being difficult to coat through a more reasonable structure.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an extrusion screw heating coating head includes a cooperating upper die and a lower die, and a gasket disposed between the upper die and the lower die; wherein, the upper die is provided with a micrometer flow equalization adjustment mechanism, the lower die is provided with a material cavity and a slurry inlet communicating with the material cavity, a die slit and a slurry outlet are formed between the upper die and the lower die, and the slurry outlet communicates with the material cavity through the die slit; both the upper die and the lower die are provided with heating components; a bidirectional screw is built into the material cavity of the lower die;

[0009] The two spiral grooves on the bidirectional screw have opposite spiral directions from the middle to both sides;

[0010] A motor is fixed on the outer wall of the lower mold, and the drive end of the motor is connected to a bidirectional screw.

[0011] As a limitation of this utility model, both ends of the bidirectional screw are rotatably connected to the lower mold via a sealed bearing assembly;

[0012] The sealed bearing assembly includes a fixed bearing assembly and a floating bearing assembly; the end of the double-ended screw fixed in the fixed bearing assembly is the fixed end, and the end of the double-ended screw fixed in the floating bearing assembly is the floating end;

[0013] The fixed end of the bidirectional screw is connected to the drive end of the motor.

[0014] As a further limitation of this utility model, the fixed bearing assembly includes a fixed bearing seat fixedly mounted at one end of the lower die cavity, a first bearing assembled in the fixed bearing seat, and a first bearing seat end cap fixedly mounted on the fixed bearing seat.

[0015] The fixed end of the bidirectional screw is fixed in the first bearing and positioned by a shaft spring washer;

[0016] A first axial sealing ring is fitted on the fixed end of the bidirectional screw to seal the gap between the fixed end and the fixed bearing seat;

[0017] The fixed bearing housing is fitted with a second axial sealing ring to seal the gap between the fixed bearing housing and the lower mold mounting hole.

[0018] As a further definition of this utility model, the floating bearing assembly includes a floating bearing seat fixedly mounted at the other end of the lower die cavity, a second bearing assembled in the floating bearing seat, and a second bearing seat end cap fixedly mounted on the floating bearing seat.

[0019] The floating end of the bidirectional screw is fixed in the second bearing and positioned by a shaft spring washer;

[0020] A first axial sealing ring is fitted on the moving end of the bidirectional screw to seal the gap between the moving end and the moving bearing housing;

[0021] The floating bearing housing is fitted with a second axial sealing ring to seal the gap between the floating bearing housing and the lower mold mounting hole.

[0022] As another limitation of this utility model, the heating component includes a plurality of heating rods evenly distributed in the upper mold and the lower mold, as well as an upper mold temperature sensor disposed in the upper mold and a lower mold temperature sensor disposed in the lower mold.

[0023] As a further limitation of this utility model, a buffer groove is also provided on the lower mold. The buffer groove is located between the material cavity and the slurry outlet, and is connected to the material cavity and the slurry outlet through the mold seam.

[0024] As a further limitation of this utility model, a pressure sensor for monitoring the pressure of slurry in the material cavity is fixed on the upper mold.

[0025] As a further limitation of this utility model, the micrometer flow equalization adjustment mechanism includes a plurality of micrometer flow equalization adjustment units evenly spaced in the upper mold along the length direction of the upper mold; the cut-off working ends of the plurality of micrometer flow equalization adjustment units are collinear and located between the buffer tank and the slurry outlet.

[0026] By adopting the above-mentioned technical solution, the beneficial effects achieved by this utility model compared with the prior art are as follows:

[0027] (1) High-viscosity slurry is a non-Newtonian fluid, exhibiting shear-thinning and heating-thinning fluid characteristics. This invention utilizes this characteristic by incorporating a motor-driven bidirectional screw into the slurry chamber. The bidirectional screw bidirectionally transports the slurry (from the slurry inlet to both ends of the chamber) and continuously stirs it, reducing the slurry viscosity and improving its fluidity. Simultaneously, heating components are added to the upper and lower molds to heat the flowing slurry to a specified temperature (determined based on the slurry characteristics), further reducing its viscosity and improving its fluidity. This invention effectively solves the current problem of unstable and uneven lateral flow velocity and flow rate at the slurry outlet due to high viscosity and large pressure loss along the flow path, making it difficult to ensure uniform and stable coating.

[0028] This invention combines heating and screw-assisted circulation. Compared to heating alone, this invention can further improve the fluidity of the conveyed slurry and reduce the slurry inlet pressure. Using this invention, a higher standard coating process can be achieved.

[0029] The bidirectional screw in this invention is built into the material cavity and supported at both ends by sealed bearing assemblies. The auxiliary circulation function can be completed by controlling the rotation speed of the bidirectional screw by a motor. The control program is simple, the structure is simple and reasonable, the initial installation and subsequent maintenance are convenient, the overall structure occupies a small area and has a low manufacturing cost.

[0030] (2) In this utility model, the end of the bidirectional screw and the bearing seat are sealed with a first axial sealing ring, and the bearing seat and the lower mold are sealed with a second axial sealing ring, which can effectively prevent slurry leakage.

[0031] (3) The overall design of the cavity of this utility model has multiple flow equalization effects, which can greatly increase the stability of the transverse flow velocity and flow rate at the slurry outlet, thereby ensuring the uniformity and stability of the coating.

[0032] Specifically: the slurry is laterally dispersed in the material cavity by a bidirectional screw to achieve uniform flow; after initial uniform flow, the slurry is squeezed and enters the die gap from the material cavity, the flow channel becomes smaller, and the flow resistance of the slurry increases, thus achieving secondary uniform flow; after secondary uniform flow, the slurry enters the buffer tank and is continuously squeezed into the die gap, which can perform tertiary buffer uniform flow; the micrometer uniform flow adjustment mechanism adjusts the height of the die gap, which can perform tertiary uniform flow of the slurry.

[0033] (4) The present invention is equipped with a pressure sensor for real-time monitoring of the slurry pressure in the material chamber, which enables the negative feedback adjustment of the feeding pressure based on the monitored values ​​to ensure the stability of coating. Attached Figure Description

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model;

[0036] Figure 2 This is a longitudinal section diagram along the width direction of an embodiment of the present utility model;

[0037] Figure 3 This is a longitudinal section diagram of an embodiment of the present invention along its length.

[0038] Figure 4 This is a schematic diagram of the bidirectional screw in an embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram showing the disassembled structure of the fixed bearing assembly in an embodiment of this utility model;

[0040] Figure 6 This is a schematic diagram showing the disassembled structure of the floating bearing assembly in an embodiment of this utility model;

[0041] Figure 7 This is an assembly diagram of the heating components on the upper and lower molds in an embodiment of this utility model;

[0042] In the diagram: 1. Upper mold; 2. Lower mold; 3. Gasket; 4. Micrometer flow equalization mechanism; 5. Material cavity; 6. Slurry inlet; 7. Mold gap; 8. Slurry outlet; 9. Buffer tank; 10. Cut-off working end; 11. Bidirectional screw; 12. Motor; 13. Fixed bearing assembly; 14. Floating bearing assembly; 15. Fixed bearing seat; 16. First bearing; 17. First bearing seat end cover; 18. First axial seal ring; 19. Second axial seal ring; 20. Shaft spring washer; 21. Floating bearing seat; 22. Second bearing; 23. Second bearing seat end cover; 24. Heating rod; 25. Upper mold temperature sensor; 26. Lower mold temperature sensor; 27. Pressure sensor. Detailed Implementation

[0043] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0044] Example 1: An extrusion screw heated coating head

[0045] This embodiment is an extrusion coating head with screw circulation auxiliary function and heating function for high viscosity slurry. The bidirectional screw 11 continuously agitates the slurry to provide power and transport the slurry to both ends of the material chamber 5. At the same time, the heating component heats the slurry to improve its fluidity, which can reduce the viscosity of the slurry, improve the fluidity of the slurry, and thus enhance the coating characteristics of the slurry.

[0046] like Figures 1 to 7 As shown, this embodiment includes an upper mold 1, a lower mold 2, and a gasket 3. The upper mold 1 and the lower mold 2 are fitted together, and the gasket 3 is located between the upper mold 1 and the lower mold 2. The upper mold 1 is equipped with a micrometer-sized flow equalization mechanism 4, and the upper surface of the lower mold 2 has a material cavity 5. A slurry inlet 6, communicating with the material cavity 5, is located at the middle position of the side of the lower mold 2. After the upper mold 1 and the lower mold 2 are fitted together, a mold slit 7 and a slurry outlet 8 are formed between them for slurry passage. The slurry outlet 8 is the end structure of the mold slit 7 and communicates with the material cavity 5 through the mold slit 7.

[0047] like Figure 2 As shown, the upper surface of the lower mold 2 is also provided with a buffer groove 9 along the length direction. The buffer groove 9 is located between the material cavity 5 and the slurry outlet 8, and is connected between the material cavity 5 and the slurry outlet 8 through the mold gap 7. The slurry in the material cavity 5 flows through the mold gap 7 and then flows evenly through the buffer groove 9, and is then evenly coated on the collector through the slurry outlet 8.

[0048] Both ends of the lower mold 2 are provided with mounting holes that communicate with the material cavity 5.

[0049] The micrometer flow equalization adjustment mechanism 4 adjusts the slurry flow rate by intercepting the flow. The micrometer flow equalization adjustment mechanism 4 includes several micrometer flow equalization adjustment units evenly spaced in the upper mold 1 along the length direction of the upper mold 1. The intercepting working ends 10 of all micrometer flow equalization adjustment units are collinear, and the intercepting working ends 10 are all located above the mold gap 7 between the buffer tank 9 and the slurry outlet 8.

[0050] The micrometer flow equalization regulating unit in this embodiment is an existing structure, and will not be described in detail here.

[0051] Furthermore, in this embodiment, a bidirectional screw 11 is built into the material cavity 5 of the lower mold 2, and a motor 12 is fixedly mounted on the outer wall of the lower mold 2. The motor 12 can be a stepper motor 12 or a servo motor 12. Figure 3 , Figure 4 As shown, the helical groove on the bidirectional screw 11 is divided into two sections from the middle to both sides, and the helical directions of the two sections are opposite. The two ends of the bidirectional screw 11 are rotatably connected to the lower mold 2 through a sealed bearing assembly. One end of the bidirectional screw 11 is connected to the drive end of the motor 12, and the bidirectional screw 11 can rotate at a predetermined speed under the drive of the motor 12.

[0052] Because the slurry inlet 6 is located at the very center, the slurry, due to its high viscosity and poor flowability, initially accumulates in the middle after flowing into the slurry chamber 5. Therefore, under the continuous stirring of the bidirectional screw 11, the slurry is transported from the center of the slurry chamber 5 to both ends, ensuring that the slurry is evenly distributed within the slurry chamber 5. In addition, the continuous stirring of the bidirectional screw 11 can also increase the shear effect between the slurry particles, reduce the slurry viscosity, and improve the problem of high lateral flow resistance of the slurry.

[0053] like Figure 4 As shown, the sealed bearing assembly includes a fixed bearing assembly 13 and a floating bearing assembly 14. The end of the bidirectional screw 11 fixed in the fixed bearing assembly 13 is the fixed end, and the end fixed in the floating bearing assembly 14 is the floating end. In this embodiment, the fixed end of the bidirectional screw 11 is connected to the drive end of the motor 12.

[0054] like Figure 5 As shown, the fixed bearing assembly 13 includes a fixed bearing housing 15, a first bearing 16, and a first bearing housing end cap 17. The fixed bearing housing 15 is fixedly installed in the mounting hole at one end of the lower mold 2, and two second axial sealing rings 19 are fitted on the outer side of the fixed bearing housing 15 to seal the gap between the fixed bearing housing 15 and the mounting hole of the lower mold 2; the first bearing 16 is assembled inside the fixed bearing housing 15. In this embodiment, two first bearings 16 are provided, both of which are deep groove ball bearings; the first bearing housing end cap 17 is fixedly installed on the fixed bearing housing 15 to cover the outer end of the fixed bearing housing 15. In this embodiment, the center of the first bearing housing end cap 17 has a through hole for the fixed end of the bidirectional screw 11 to pass through.

[0055] The fixed end of the bidirectional screw 11 is fixedly mounted inside the first bearing 16 and passes through the through hole of the first bearing housing end cover 17 to connect to the drive end of the motor 12. To prevent the first bearing 16 from axially moving on the bidirectional screw 11, a shaft spring washer 20 for positioning the first bearing 16 is fitted on the outside of the first bearing 16 on the bidirectional screw 11. In this embodiment, a first axial sealing ring 18 for sealing the gap between the fixed end and the fixed bearing housing 15 is also fitted on the fixed end of the bidirectional screw 11.

[0056] like Figure 6 As shown, the floating bearing assembly includes a floating bearing housing 21, a second bearing 22, and a second bearing housing end cap 23. The floating bearing housing 21 is fixedly installed in the mounting hole at the other end of the lower mold 2, and two second axial sealing rings 19 are also fitted on the outer side of the floating bearing housing 21 to seal the gap between the floating bearing housing 21 and the mounting hole of the lower mold 2; the second bearing 22 is assembled inside the floating bearing housing 21, and in this embodiment, two second bearings 22 are also provided, which are also deep groove ball bearings; the second bearing housing end cap 23 is fixedly installed on the floating bearing housing 21 to cover the outer end of the floating bearing housing 21.

[0057] The movable end of the double-acting screw 11 is fixedly mounted inside the second bearing 22. To prevent the second bearing 22 from moving axially on the double-acting screw 11, a shaft spring washer 20 for positioning the second bearing 22 is fitted on the outside of the double-acting screw 11. In this embodiment, a first axial sealing ring 18 for sealing the gap between the movable end and the movable bearing seat 21 is also fitted on the movable end of the double-acting screw 11.

[0058] More specifically, in this embodiment, both the upper mold 1 and the lower mold 2 are equipped with heating components to achieve the heating function and heat the flowing slurry.

[0059] like Figure 7 As shown, the heating assembly includes several heating rods 24 evenly distributed in the upper mold 1 and the lower mold 2, as well as an upper mold temperature sensor 25 disposed in the upper mold 1 and a lower mold temperature sensor 26 disposed in the lower mold 2. This embodiment utilizes the heating rods 24 for heating and the upper mold temperature sensor 25 and lower mold temperature sensor 26 for temperature measurement, enabling an adjustable heating temperature of 60–95°C with a control accuracy of ±1°C. Therefore, in actual operation, a specific temperature value can be determined based on the characteristics of the slurry, allowing the slurry to be precisely heated to the designated temperature, resulting in reduced viscosity and improved fluidity.

[0060] In this embodiment, one upper mold temperature sensor 25 is provided at each end of the upper mold 1, one for temperature measurement and the other for inspection, so that an alarm can be triggered if one fails, allowing staff to promptly detect and replace it. Correspondingly, one lower mold temperature sensor 26 is also provided at each end of the lower mold 2.

[0061] It should be noted that, depending on the actual situation, the heating function is not limited to being achieved through a heating rod 24; it can also be achieved through a silicone heating element, a circuit board heating element, or other similar means.

[0062] In addition, in order to monitor the pressure of the slurry in the material cavity 5 in real time, a pressure sensor 27 is provided at the middle position of the upper mold 1 in this embodiment, and the working end of the pressure sensor 27 extends into the material cavity 5.

[0063] It should be noted that the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An extrusion screw heated coating head, comprising a mating upper die, a lower die, and a gasket disposed between the upper die and the lower die; wherein, The upper mold is equipped with a micrometer flow equalization adjustment mechanism, and the lower mold is equipped with a material cavity and a slurry inlet connected to the material cavity. A mold gap and a slurry outlet are formed between the upper mold and the lower mold, and the slurry outlet is connected to the material cavity through the mold gap. The feature is that both the upper mold and the lower mold are equipped with heating components; a bidirectional screw is built into the material cavity of the lower mold. The two spiral grooves on the bidirectional screw have opposite spiral directions from the middle to both sides; A motor is fixed on the outer wall of the lower mold, and the drive end of the motor is connected to a bidirectional screw.

2. The extrusion screw heated coating head according to claim 1, characterized in that: The two ends of the bidirectional screw are rotatably connected to the lower mold via sealed bearing assemblies; The sealed bearing assembly includes a fixed bearing assembly and a floating bearing assembly; the end of the double-ended screw fixed in the fixed bearing assembly is the fixed end, and the end of the double-ended screw fixed in the floating bearing assembly is the floating end; The fixed end of the bidirectional screw is connected to the drive end of the motor.

3. The extrusion screw heated coating head according to claim 2, characterized in that: The fixed bearing assembly includes a fixed bearing housing fixedly mounted at one end of the lower die cavity, a first bearing assembled in the fixed bearing housing, and a first bearing housing end cap fixedly mounted on the fixed bearing housing. The fixed end of the bidirectional screw is fixed in the first bearing and positioned by a shaft spring washer; A first axial sealing ring is fitted on the fixed end of the bidirectional screw to seal the gap between the fixed end and the fixed bearing seat; The fixed bearing housing is fitted with a second axial sealing ring to seal the gap between the fixed bearing housing and the lower mold mounting hole.

4. The extrusion screw heated coating head according to claim 3, characterized in that: The floating bearing assembly includes a floating bearing housing fixedly mounted at the other end of the lower die cavity, a second bearing assembled inside the floating bearing housing, and a second bearing housing end cap fixedly mounted on the floating bearing housing. The floating end of the bidirectional screw is fixed in the second bearing and positioned by a shaft spring washer; A first axial sealing ring is fitted on the moving end of the bidirectional screw to seal the gap between the moving end and the moving bearing housing; The floating bearing housing is fitted with a second axial sealing ring to seal the gap between the floating bearing housing and the lower mold mounting hole.

5. The extrusion screw heated coating head according to any one of claims 1-4, characterized in that: The heating assembly includes several heating rods evenly distributed in the upper and lower molds, as well as an upper mold temperature sensor in the upper mold and a lower mold temperature sensor in the lower mold.

6. The extrusion screw heated coating head according to claim 5, characterized in that: The lower mold is also equipped with a buffer groove, which is located between the material cavity and the slurry outlet, and is connected to the material cavity and the slurry outlet through the mold gap.

7. The extrusion screw heated coating head according to claim 6, characterized in that: A pressure sensor for monitoring the pressure of the slurry in the material cavity is fixed on the upper mold.

8. The extrusion screw heated coating head according to claim 6 or 7, characterized in that: The micrometer flow equalization adjustment mechanism includes several micrometer flow equalization adjustment units evenly spaced along the length of the upper mold; the cut-off working ends of the several micrometer flow equalization adjustment units are collinear and located between the buffer tank and the slurry outlet.

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