Huff and puff piston device for thickness adjustment of head part and tail part of pole piece of extrusion coating machine

Abstract

The invention provides a throughput piston device for thickness adjustment of the head and the tail of a pole piece of an extrusion coating machine, the throughput piston device comprises a piston cylinder assembly, a piston rod assembly, a piston rod driving assembly and a first hoop, the piston cylinder assembly is respectively connected with the piston rod assembly and the piston rod driving assembly; the piston rod assembly is connected with the piston rod driving assembly and arranged in the piston cylinder assembly in a sleeved mode. In the piston rod assembly, one end of a piston rod is connected to a first linear bearing through a check ring, and the other end of the piston rod is connected to a locking structure through an O-shaped sealing ring, a spring seal and a sealing gasket. In the piston rod driving assembly, an upper connecting plate is connected to a lower connecting plate through a connecting shaft and a second linear bearing, and an eccentric wheel is connected with a servo motor. The coating thickness of the head and the tail of the pole piece can be adjusted, the uniformity degree of an electrode material on the pole piece is effectively improved, and the production efficiency and the product yield of the pole piece are improved.

Description

Technical Field

[0001] The invention relates to a piston device of an extrusion coating machine, in particular to a throughput piston device for adjusting the thickness of a head and a tail of a pole piece of the extrusion coating machine. Background Art

[0002] Compared with traditional batteries, lithium-ion batteries have the advantages of higher energy, stronger discharge capacity and longer cycle life, and their energy storage efficiency can exceed 90%, and their safety performance is good. Therefore, lithium-ion batteries have great development prospects in electric vehicles and storage power sources. There are two main ways to coat the pole pieces in the production process of lithium-ion batteries: extrusion and transfer; the transfer coating method mainly relies on coating rollers, scrapers and back rollers; the extrusion coating method mainly relies on coating valves, reflux valves, extrusion heads and coating rollers.

[0003] The extrusion coating system is closed, which can prevent pollutants from entering during the coating process. Therefore, it has the advantages of high slurry utilization and stable slurry properties, and can adapt to different slurry viscosity ranges. Compared with the transfer coating process, it has stronger adaptability and is also the main coating method currently used in the front-end of lithium batteries.

[0004] However, the intermittent coating of the extrusion coating method relies on the high-speed switching between the coating valve and the reflux valve. The pulling force and thrust generated by the coating valve core and the reflux valve core at high speed switching will affect the pressure of the slurry in the inner cavity of the extrusion head, which will cause the head of the pole piece to be thicker and the tail to be thinner during coating. This phenomenon will directly affect the neatness of the winding of the pole piece after drying and the subsequent rolling process, resulting in inconsistent lateral density of the pole piece after rolling, thus warping to form a serpentine pole piece, affecting the subsequent strip processing and easily producing defective products; even, it will cause problems such as uneven current distribution during the charging and discharging process of the battery. Summary of the invention

[0005] The technical problem to be solved by the present invention is that it is necessary to provide a throughput piston device for adjusting the thickness of the head and tail of the electrode of an extrusion coating machine, aiming to effectively improve the uniformity of the electrode material on the electrode, avoid the phenomenon that the head of the electrode is too thick and the tail is too thin, and improve the production efficiency and product yield of the electrode.

[0006] To this end, the present invention provides a throughput piston device for adjusting the thickness of the head and tail of the pole piece of an extrusion coating machine, comprising: a piston cylinder assembly, a piston rod assembly, a piston rod driving assembly and a first clamp, wherein the piston cylinder assembly is respectively connected to the piston rod assembly and the piston rod driving assembly; the piston rod assembly is connected to the piston rod driving assembly and is sleeved in the piston cylinder assembly; wherein the piston cylinder assembly comprises a three-way pipe, a piston cylinder body, a guide cylinder body and a connecting flange, the piston cylinder body is connected to the three-way pipe through a first clamp, and the piston cylinder body is connected to the connecting flange through a guide cylinder body; the piston rod assembly comprises a locking structure, a sealing gasket, a pan seal, an O-ring, a piston rod, a retaining ring and a first linear bearing, one end of the piston rod is connected to the first linear bearing through a retaining ring, and the piston rod The other end is connected to the locking structure through an O-ring, a pan seal and a sealing gasket; the piston rod drive assembly includes an upper connecting plate, a connecting shaft, an eccentric wheel, a lower connecting plate, a motor seat, a servo motor, a first bearing, a second bearing and a second linear bearing, and the upper connecting plate is connected to the lower connecting plate through a connecting shaft and a second linear bearing, and is arranged on the motor seat; the eccentric wheel is arranged in the motor seat through the first bearing and the second bearing, and is connected to the servo motor; during extrusion coating, the servo motor of the piston rod drive assembly drives the rotation of the eccentric wheel to drive the movement of the upper connecting plate, and makes the piston rod of the piston rod assembly move in the piston cylinder body of the piston cylinder assembly, thereby adjusting the slurry volume inside the extrusion head to achieve control and regulation of the coating thickness.

[0007] A further improvement of the present invention is that the assembly process of the throughput piston device comprises the following steps: Step S1, firstly sleeve the O-ring on the piston rod, then sleeve the pan seal on the piston rod, and fix the sealing gasket on the piston rod by the locking structure to obtain an assembled first component; Step S2, first, assemble a retaining ring in the guide cylinder body, install the first linear bearing into the guide cylinder body and then install another retaining ring; then, insert one end of the first component assembled in step S1 into the first linear bearing in the guide cylinder body, and insert the other end into the piston cylinder body; then, assemble the piston cylinder body with the guide cylinder body, assemble the three-way pipe with the piston cylinder body through the first clamp, and connect the guide cylinder body with the connecting flange to obtain the second component; Step S3, the eccentric wheel is assembled in the motor base through the first bearing and the second bearing, and the first bearing and the second bearing are respectively arranged on the end of the eccentric wheel and the mounting shaft; the motor shaft of the servo motor is inserted into the eccentric wheel and fixed on the motor base; two second linear bearings are respectively installed on both sides of the motor base; two connecting shafts are inserted into the second linear bearings on both sides, and the upper connecting plate and the lower connecting plate are respectively installed at the upper and lower ends of the connecting shaft, so that the upper connecting plate and the lower connecting plate are respectively tangent to the second bearings, so as to obtain a third component; Step S4, connect the second component assembled in step S2 with the third component assembled in step S3, fix the piston rod to the upper connecting plate by threads, connect one pipe joint of the three-way pipe to the pipe of the coating valve, and connect the other pipe joint to the pipe of the extrusion head to complete the assembly of the throughput piston device.

[0008] A further improvement of the present invention is that the assembly process of the throughput piston device also includes step S5, according to the coating thickness requirement, first trial coating a preset length, and after trial coating the preset length, measure the head thickness, middle thickness and tail thickness of the electrode piece, and determine whether the difference between the head thickness, middle thickness and tail thickness of the electrode piece and the required coating thickness is less than a preset thickness difference threshold. If so, the process is completed; if not, adjust the displacement of the piston rod of the throughput piston device, restart and return to the trial coating preset length until the difference between the head thickness, middle thickness and tail thickness of the electrode piece and the required coating thickness is less than the preset thickness difference threshold.

[0009] A further improvement of the present invention is that the process of adjusting the displacement of the piston rod of the throughput piston device is: the servo motor of the piston rod driving assembly drives the rotational movement of the eccentric wheel to drive the movement of the upper connecting plate, and makes the piston rod connected to the upper connecting plate move in the piston cylinder, thereby generating negative pressure or positive pressure to adjust the slurry volume inside the extrusion head, thereby realizing the control and regulation of the coating thickness.

[0010] A further improvement of the present invention is that, when adjusting the coating thickness of the head and tail of the pole piece, the head thickness, middle thickness and tail thickness of the pole piece after the preset length of trial coating are first measured, and the slurry volume required to be increased or decreased for each is calculated; then the rotation angle of the eccentric wheel is controlled by the servo motor, so that the piston rod performs a linear reciprocating motion in the piston cylinder, and the slurry volume inside the extrusion head is changed accordingly by the required increase or decrease amount, thereby realizing the thickness adjustment of the head and tail of the pole piece during coating.

[0011] A further improvement of the present invention is that it further comprises a second clamp, and in the piston-cylinder assembly, the piston cylinder body and the guide cylinder body, and the guide cylinder body and the connecting flange are connected via the second clamp.

[0012] A further improvement of the present invention is that the locking structure comprises a hexagonal head bolt and a pressure plate, and the hexagonal head bolt fixes the pressure plate above the sealing gasket.

[0013] A further improvement of the present invention is that the piston rod assembly further comprises a guide belt, and the guide belt is arranged between the flood seal and the O-ring.

[0014] A further improvement of the present invention is that in the step S2, the small end of the first component is inserted into the first linear bearing of the guide cylinder body, and the large end of the first component is inserted into the piston cylinder body.

[0015] A further improvement of the present invention is that the piston rod drive assembly also includes a fixed block and a connecting block, the fixed block is arranged on the top of the upper connecting plate, and the fixed block is connected to the piston rod through the connecting block; the connecting flange adopts a throughput valve flange, and the top and bottom of the throughput valve flange are provided with limiting steps.

[0016] Compared with the prior art, the beneficial effects of the present invention are: it includes a piston cylinder assembly, a piston rod assembly, a piston rod drive assembly and a first clamp, the piston cylinder assembly is connected to the piston rod assembly and the piston rod drive assembly respectively; the piston rod assembly is connected to the piston rod drive assembly and is sleeved in the piston cylinder assembly, and during extrusion coating, the servo motor of the piston rod drive assembly can drive the rotation of the eccentric wheel to drive the movement of the upper connecting plate, and make the piston rod of the piston rod assembly move in the piston cylinder body of the piston cylinder assembly, thereby adjusting the slurry volume inside the extrusion head to achieve control and adjustment of the coating thickness. Therefore, the present invention can adjust the coating thickness of the head and tail of the electrode piece, which well solves the problem of thick head and thin tail caused by high-speed switching of the coating valve and the reflux valve in the prior art, effectively improves the uniformity of the electrode material on the electrode piece, and improves the production efficiency and product yield of the electrode piece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an embodiment of the present invention; Figure 2 is a schematic diagram of a transverse cross-sectional structure of an embodiment of the present invention; Figure 3 It is a schematic diagram of the longitudinal cross-sectional structure of an embodiment of the present invention; Figure 4It is a schematic diagram of the structure of an embodiment of the present invention after the piston cylinder assembly is hidden; Figure 5 It is a structural schematic diagram of a piston-cylinder assembly according to an embodiment of the present invention; Figure 6 is a structural schematic diagram of a piston rod assembly according to an embodiment of the present invention; Figure 7 is a structural schematic diagram of a piston rod drive assembly according to an embodiment of the present invention; Figure 8 It is a structural schematic diagram of a piston rod drive assembly according to an embodiment of the present invention after the motor seat is removed; Fig. 9 is a schematic cross-sectional structure diagram of a piston rod drive assembly according to an embodiment of the present invention; Fig.10 It is a schematic diagram of the structure of an embodiment of the present invention after being applied to an extrusion coating machine.

[0018] Reference numerals: 1-piston cylinder assembly; 11-three-way pipe; 12-piston cylinder body; 13-guide cylinder body; 14-connecting flange; 141-limiting step; 2-piston rod assembly; 21-hexagonal bolt; 22-pressing plate; 23-sealing pad; 24-pan seal; 25-guide belt; 26-O-ring; 27-piston rod; 28-retaining ring; 29-first linear bearing; 3-piston rod drive assembly; 31-upper connecting plate; 32-connecting shaft; 33-eccentric wheel; 34-lower connecting plate; 35-motor seat; 36-servo motor; 37-first bearing; 38-second bearing; 39-second linear bearing; 310-fixed block; 311-connecting block; 4- first clamp; 5- second clamp; 6-Coating valve; 7- Extrusion head. DETAILED DESCRIPTION

[0019] In the description of the present invention, if it involves a description of orientation, for example, the orientation or position relationship indicated by "upper", "lower", "front", "back", "left", "right", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. If a certain technical feature is referred to as "set", "fixed", "connected", or "installed" on another technical feature, it can be directly set, fixed, or connected to the other technical feature, or it can be indirectly set, fixed, connected, or installed on the other technical feature.

[0020] In the description of the present invention, if "several" is involved, it means more than one; if "multiple" is involved, it means more than two; if "greater than", "less than", or "exceed" is involved, it should be understood as not including the number itself; if "above", "below", or "within" is involved, it should be understood as including the number itself. If "first", "second", etc. are involved, they should be understood as being used only to distinguish the names of the same or similar technical features, and should not be understood as implying / indicating the relative importance of the technical features, the number of the technical features, or the order of the technical features.

[0021] The preferred embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0022] like Figures 1 to 10As shown, this embodiment provides a throughput piston device for adjusting the thickness of the head and tail of the pole piece of an extrusion coating machine, comprising: a piston cylinder assembly 1, a piston rod assembly 2, a piston rod driving assembly 3 and a first clamp 4, wherein the piston cylinder assembly 1 is connected to the piston rod assembly 2 and the piston rod driving assembly 3 respectively; the piston rod assembly 2 is connected to the piston rod driving assembly 3 and is sleeved in the piston cylinder assembly 1; wherein the piston cylinder assembly 1 comprises a three-way pipe 11, a piston cylinder body 12, a guide cylinder body 13 and a connecting flange 14, The piston cylinder 12 is connected to the three-way pipe 11 through the first clamp 4, and the piston cylinder 12 is connected to the connecting flange 14 through the guide cylinder 13; the piston rod assembly 2 includes a locking structure, a sealing gasket 23, a pan seal 24, an O-ring 26, a piston rod 27, a retaining ring 28 and a first linear bearing 29, one end of the piston rod 27 is connected to the first linear bearing 29 through the retaining ring 28, and the other end of the piston rod 27 is connected to the locking structure through the O-ring 26, the pan seal 24 and the sealing gasket 23 Structure; The piston rod assembly 2 is equipped with a first linear bearing 29, which can play a good guiding role and prevent the piston device from getting stuck due to deflection after long-term use; the piston rod drive assembly 3 includes an upper connecting plate 31, a connecting shaft 32, an eccentric wheel 33, a lower connecting plate 34, a motor seat 35, a servo motor 36, a first bearing 37, a second bearing 38 and a second linear bearing 39. The upper connecting plate 31 is connected to the lower connecting plate 34 through the connecting shaft 32 and the second linear bearing 39, and is arranged on the motor seat 3 5; the eccentric wheel 33 is arranged in the motor seat 35 through the first bearing 37 and the second bearing 38, and is connected to the servo motor 36. During extrusion coating, the servo motor 36 of the piston rod drive assembly 3 drives the rotation of the eccentric wheel 33 to drive the movement of the upper connecting plate 31, and makes the piston rod 27 of the piston rod assembly 2 move in the piston cylinder body 12 of the piston cylinder assembly 1, thereby adjusting the slurry volume inside the extrusion head 7 to achieve control and regulation of the coating thickness. In the piston rod drive assembly 3, the servo motor 36 is used as the driving device of the piston structure, and the rotation of the servo motor 36 is converted into a linear reciprocating motion through the eccentric wheel 33, so as to achieve reliable regulation and control. The pan seal 24 is also called a one-way seal ring.

[0023] The assembly process of the throughput piston device of this embodiment includes the following steps: Step S1, first sleeve the O-ring 26 on the piston rod 27, then sleeve the flood seal 24 on the piston rod 27, and fix the sealing gasket 23 on the piston rod 27 through the locking structure to obtain an assembled first component; the first component refers to the component after assembling part of the structure of the piston rod assembly 2; Step S2, first, assemble a retaining ring 28 in the guide cylinder 13, install the first linear bearing 29 into the guide cylinder 13 and then install another retaining ring 28; then, insert one end of the first component assembled in step S1 into the first linear bearing 29 in the guide cylinder 13, and insert the other end into the piston cylinder 12; then, assemble the piston cylinder 12 and the guide cylinder 13, preferably through the second clamp 5; assemble the three-way pipe 11 and the piston cylinder 12 through the first clamp 4; and connect the guide cylinder 13 to the connecting flange 14, preferably through the second clamp 5 to obtain the second component; the second component refers to the component after the piston rod assembly 2 is assembled to the piston cylinder assembly 1; Step S3, the eccentric wheel 33 is assembled in the motor seat 35 through the first bearing 37 and the second bearing 38, and the first bearing 37 and the second bearing 38 are respectively arranged on the end and the mounting shaft of the eccentric wheel 33; the motor shaft of the servo motor 36 is inserted into the eccentric wheel 33 and fixed on the motor seat 35; two second linear bearings 39 are respectively installed on both sides of the motor seat 35 to prevent the direction from being offset during the movement and ensure reliable guidance of the movement; two connecting shafts 32 are inserted into the second linear bearings 39 on both sides, and the upper connecting plate 31 and the lower connecting plate 34 are respectively installed at the upper and lower ends of the connecting shaft 32, so that the upper connecting plate 31 and the lower connecting plate 34 are respectively tangent to the second bearing 38, and a third component is obtained; the third component refers to the component after the piston rod drive assembly 3 is assembled; Step S4, connect the second component assembled in step S2 with the third component assembled in step S3, fix the piston rod 27 and the upper connecting plate 31 by threads, connect one pipe joint of the three-way pipe 11 to the pipe of the coating valve 6, and connect the other pipe joint to the pipe of the extrusion head 7, so as to complete the assembly of the throughput piston device, as shown in FIG. Fig.10 shown.

[0024] It is worth noting that the assembly process of the throughput piston device described in this embodiment also includes step S5. According to the coating thickness requirement, a preset length is first trial-coated, and the head thickness, middle thickness and tail thickness of the electrode are measured after the preset length is trial-coated to determine whether the differences between the head thickness, middle thickness and tail thickness of the electrode and the required coating thickness are all less than the preset thickness difference threshold. If so, the process is completed; if not, the displacement of the piston rod 27 of the throughput piston device is adjusted, and the process is restarted and returned to the preset length of trial coating until the differences between the head thickness, middle thickness and tail thickness of the electrode and the required coating thickness are all less than the preset thickness difference threshold.

[0025] The preset length described in this embodiment refers to the preset coating length, which can be adjusted according to actual conditions and needs. The thickness difference threshold refers to the preset thickness difference threshold between the coating thickness requirement, which can also be adjusted according to actual conditions and needs to ensure that the thickness difference between the head thickness, middle thickness and tail thickness of the electrode piece and the coating thickness requirement are within a controllable range, so as to improve the thickness uniformity of the electrode piece and reduce the defective rate of the electrode piece due to the thickness difference between the head and tail. In this embodiment, it is preferred to perform a trial coating and debugging process through step S5 before formal production, and then start formal production only after ensuring that the difference between the head thickness, middle thickness and tail thickness of the electrode piece and the required coating thickness is less than the preset thickness difference threshold, which can effectively improve the uniformity of the electrode material on the electrode piece during the actual production process, and improve the production efficiency and product yield of the electrode piece.

[0026] More specifically, the process of adjusting the displacement of the piston rod 27 of the throughput piston device in this embodiment is: the servo motor 36 of the piston rod driving assembly 3 drives the rotation of the eccentric wheel 33 to drive the movement of the upper connecting plate 31 (i.e., linear reciprocating motion in the vertical direction), and makes the piston rod 27 connected to the upper connecting plate 31 move in the piston cylinder 12, thereby generating negative pressure or positive pressure to adjust the slurry volume inside the extrusion head 7, thereby realizing the control and regulation of the coating thickness.

[0027] In this embodiment, when adjusting the coating thickness of the head and tail of the pole piece, the head thickness, middle thickness and tail thickness of the pole piece after the preset length of trial coating are first measured, and the slurry volume required to be increased or decreased is calculated, and the slurry volume is calculated by multiplying the coating area and the coating thickness; then, the rotation angle of the eccentric wheel 33 is controlled by the servo motor 36, so that the piston rod 27 performs a linear reciprocating motion in the piston cylinder 12, and the slurry volume inside the extrusion head 7 is changed according to the amount required to increase or decrease (that is, the slurry volume required to be increased or decreased calculated above), thereby realizing the thickness adjustment of the head and tail of the pole piece during coating.

[0028] like Figure 1 and Figure 5 As shown, this embodiment further includes a second clamp 5, and in the piston-cylinder assembly 1, the piston cylinder body 12 and the guide cylinder body 13, as well as the guide cylinder body 13 and the connecting flange 14 are all connected via the second clamp 5. That is to say, each structure of the piston-cylinder assembly 1 in this embodiment is preferably assembled detachably using a clamp structure, and this quick-release clamp design is more conducive to the subsequent quick disassembly, cleaning and maintenance.

[0029] like Figure 1 and Figure 6 As shown, the locking structure of this embodiment includes a hexagonal bolt 21 and a pressure plate 22, and the hexagonal bolt 21 fixes the pressure plate 22 above the sealing gasket 23. The sealing gasket 23 preferably adopts an EPDM sealing gasket to play a sealing role and prevent corrosion by slurry; at the same time, the matching pan seal 24 and O-ring 26 are used to prevent the EPDM sealing gasket from leaking due to long-term use and wear, which well ensures the reliability and service life of the product. Preferably, the piston rod assembly 2 of this embodiment also includes a guide belt 25, which is arranged between the pan seal 24 and the O-ring 26 to play a guiding and protective role.

[0030] In the step S2 of the present embodiment, the small end of the first component, that is, the smaller lower end, is inserted into the first linear bearing 29 of the guide cylinder body 13; and the large end of the first component, that is, the larger upper end, is inserted into the piston cylinder body 12.

[0031] like Figure 4 as well as Figures 8 to 9 As shown, the piston rod drive assembly 3 of this embodiment further includes a fixing block 310 and a connecting block 311. The fixing block 310 is disposed on the top of the upper connecting plate 31. The fixing block 310 is connected to the piston rod 27 via the connecting block 311, so as to realize the detachable installation and linkage control of the piston rod 27. Figure 5 As shown, the connecting flange 14 of this embodiment adopts a throughput valve flange, and limiting steps 141 are provided at the top and bottom of the throughput valve flange to provide installation space and limiting effect for the second clamp 5, thereby improving the assembly efficiency and reliability of the product.

[0032] In summary, the present embodiment includes a piston cylinder assembly 1, a piston rod assembly 2, a piston rod drive assembly 3 and a first clamp 4, wherein the piston cylinder assembly 1 is connected to the piston rod assembly 2 and the piston rod drive assembly 3 respectively; the piston rod assembly 2 is connected to the piston rod drive assembly 3 and is sleeved in the piston cylinder assembly 1. During extrusion coating, the servo motor 36 of the piston rod drive assembly 3 can drive the rotation of the eccentric wheel 33 to drive the movement of the upper connecting plate 31, and make the piston rod 27 of the piston rod assembly 2 move in the piston cylinder body 12 of the piston cylinder assembly 1, thereby adjusting the slurry volume inside the extrusion head 7 to control and adjust the coating thickness. Therefore, the present embodiment can adjust the coating thickness of the head and tail of the electrode piece, which well solves the problem of thick head and thin tail caused by high-speed switching of the coating valve 6 and the reflux valve in the prior art, effectively improves the uniformity of the electrode material on the electrode piece, and improves the production efficiency and product yield of the electrode piece.

[0033] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A throughput piston device for adjusting the thickness of the head and tail of an extrusion coating machine pole piece, characterized in that: include: A piston cylinder assembly (1), a piston rod assembly (2), a piston rod drive assembly (3) and a first clamp (4), wherein the piston cylinder assembly (1) is connected to the piston rod assembly (2) and the piston rod drive assembly (3) respectively; the piston rod assembly (2) is connected to the piston rod drive assembly (3) and is sleeved in the piston cylinder assembly (1); wherein the piston cylinder assembly (1) comprises a three-way pipe (11), a piston cylinder body (12), a guide cylinder body (13) and a connecting flange (14); the piston cylinder body (12) is connected to the piston cylinder body (13) through the first clamp (4 ) is connected to the three-way pipe (11), the piston cylinder (12) is connected to the connecting flange (14) through the guide cylinder (13); the piston rod assembly (2) comprises a locking structure, a sealing gasket (23), a pan seal (24), an O-ring (26), a piston rod (27), a retaining ring (28) and a first linear bearing (29), one end of the piston rod (27) is connected to the first linear bearing (29) through the retaining ring (28), and the other end of the piston rod (27) is connected to the first linear bearing (29) through the O-ring (26), the pan seal (24) and The sealing gasket (23) is connected to the locking structure; the piston rod drive assembly (3) comprises an upper connecting plate (31), a connecting shaft (32), an eccentric wheel (33), a lower connecting plate (34), a motor seat (35), a servo motor (36), a first bearing (37), a second bearing (38) and a second linear bearing (39); the upper connecting plate (31) is connected to the lower connecting plate (34) via the connecting shaft (32) and the second linear bearing (39), and is arranged on the motor seat (35); the eccentric wheel (33) is connected to the lower connecting plate (34) via the first bearing The first bearing (37) and the second bearing (38) are arranged in the motor seat (35) and are connected to the servo motor (36); during extrusion coating, the servo motor (36) of the piston rod driving assembly (3) drives the eccentric wheel (33) to rotate, thereby driving the movement of the upper connecting plate (31), and causing the piston rod (27) of the piston rod assembly (2) to move in the piston cylinder body (12) of the piston cylinder assembly (1), thereby adjusting the slurry volume inside the extrusion head (7) to achieve control and regulation of the coating thickness.

2. The throughput piston device for adjusting the thickness of the head and tail of the extrusion coating machine pole piece according to claim 1 is characterized in that: The assembly process of the throughput piston device comprises the following steps: Step S1, first sleeve the O-ring (26) onto the piston rod (27), then sleeve the pan seal (24) onto the piston rod (27), and fix the sealing gasket (23) onto the piston rod (27) via the locking structure, to obtain an assembled first component; Step S2, first, assemble a retaining ring (28) in the guide cylinder (13), install the first linear bearing (29) into the guide cylinder (13), and then install another retaining ring (28); then, insert one end of the first component assembled in step S1 into the first linear bearing (29) in the guide cylinder (13), and insert the other end into the piston cylinder (12); then, assemble the piston cylinder (12) and the guide cylinder (13), assemble the three-way pipe (11) and the piston cylinder (12) through the first clamp (4), and connect the guide cylinder (13) to the connecting flange (14), so as to obtain the second component; Step S3, the eccentric wheel (33) is assembled in the motor base (35) through a first bearing (37) and a second bearing (38), wherein the first bearing (37) and the second bearing (38) are respectively arranged at the end of the eccentric wheel (33) and on the mounting shaft; the motor shaft of the servo motor (36) is inserted into the eccentric wheel (33) and fixed on the motor base (35); two second linear bearings (39) are respectively installed on both sides of the motor base (35); two connecting shafts (32) are inserted into the second linear bearings (39) on both sides, and the upper connecting plate (31) and the lower connecting plate (34) are respectively installed on the upper and lower ends of the connecting shaft (32), so that the upper connecting plate (31) and the lower connecting plate (34) are respectively tangent to the second bearings (38), thereby obtaining a third component; Step S4, connecting the second component assembled in step S2 with the third component assembled in step S3, the piston rod (27) and the upper connecting plate (31) are fixed by threads, and one pipe joint of the three-way pipe (11) is connected to the pipe of the coating valve (6), and the other pipe joint is connected to the pipe of the extrusion head (7), so as to complete the assembly of the throughput piston device.

3. The throughput piston device for adjusting the thickness of the head and tail of the extrusion coating machine pole piece according to claim 2 is characterized in that: The assembly process of the throughput piston device also includes step S5, according to the coating thickness requirement, first trial coating a preset length, and after trial coating the preset length, measuring the head thickness, middle thickness and tail thickness of the electrode piece, and judging whether the difference between the head thickness, middle thickness and tail thickness of the electrode piece and the required coating thickness is less than a preset thickness difference threshold value, if so, completing; if not, adjusting the displacement of the piston rod (27) of the throughput piston device, restarting and returning to the trial coating preset length, until the difference between the head thickness, middle thickness and tail thickness of the electrode piece and the required coating thickness is less than the preset thickness difference threshold value.

4. The throughput piston device for adjusting the thickness of the head and tail of the extrusion coating machine pole piece according to claim 3 is characterized in that: The process of adjusting the displacement of the piston rod (27) of the throughput piston device is as follows: the servo motor (36) of the piston rod driving assembly (3) drives the rotation of the eccentric wheel (33) to drive the movement of the upper connecting plate (31), and enables the piston rod (27) connected to the upper connecting plate (31) to move in the piston cylinder (12), thereby generating negative pressure or positive pressure to adjust the slurry volume inside the extrusion head (7), thereby achieving control and adjustment of the coating thickness.

5. The throughput piston device for adjusting the thickness of the head and tail of the pole piece of the extrusion coating machine according to claim 4 is characterized in that: When adjusting the coating thickness of the head and tail of the pole piece, the head thickness, middle thickness and tail thickness of the pole piece after the preset length of trial coating are first measured, and the slurry volume required to be increased or decreased is calculated; then, the rotation angle of the eccentric wheel (33) is controlled by the servo motor (36), so that the piston rod (27) performs linear reciprocating motion in the piston cylinder (12), and the slurry volume inside the extrusion head (7) is changed by the amount required to be increased or decreased, thereby achieving the thickness adjustment of the head and tail of the pole piece during coating.

6. The throughput piston device for adjusting the thickness of the head and tail of the pole piece of the extrusion coating machine according to any one of claims 1 to 5, characterized in that: It also includes a second clamp (5), and in the piston-cylinder assembly (1), the piston cylinder body (12) and the guide cylinder body (13), as well as the guide cylinder body (13) and the connecting flange (14) are connected via the second clamp (5).

7. The throughput piston device for adjusting the thickness of the head and tail of the pole piece of the extrusion coating machine according to any one of claims 1 to 5, characterized in that: The locking structure comprises a hexagonal head bolt (21) and a pressure plate (22), wherein the hexagonal head bolt (21) fixes the pressure plate (22) above the sealing gasket (23).

8. The throughput piston device for adjusting the thickness of the head and tail of the pole piece of the extrusion coating machine according to claim 7, characterized in that: The piston rod assembly (2) further comprises a guide belt (25), wherein the guide belt (25) is arranged between the pan seal (24) and the O-ring (26).

9. The throughput piston device for adjusting the thickness of the head and tail of the pole piece of the extrusion coating machine according to any one of claims 1 to 5, characterized in that: In the step S2, the small end of the first component is inserted into the first linear bearing (29) of the guide cylinder (13), and the large end of the first component is inserted into the piston cylinder (12).

10. The throughput piston device for adjusting the thickness of the head and tail of the pole piece of the extrusion coating machine according to any one of claims 1 to 5, characterized in that: The piston rod drive assembly (3) further comprises a fixing block (310) and a connecting block (311), wherein the fixing block (310) is arranged on the top of the upper connecting plate (31), and the fixing block (310) is connected to the piston rod (27) via the connecting block (311); the connecting flange (14) is a throughput valve flange, and limiting steps (141) are arranged on the top and bottom of the throughput valve flange.

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