Integrated pump-controlled direct-drive hydraulic system of lithium battery pole piece roller press

Abstract

The utility model relates to an integrated lithium battery pole piece roller press pump control direct drive hydraulic system, which comprises a servo motor, a hydraulic constant displacement pump, a two-position four-way electromagnetic directional valve and a displacement sensor, an output shaft of the servo motor is connected with an input shaft of the hydraulic constant displacement pump, an oil inlet of the hydraulic constant displacement pump is connected with an oil outlet of an oil tank, and an oil outlet of the oil tank is connected with the two-position four-way electromagnetic directional valve. An oil discharge port of the hydraulic metering pump is connected with one port of the two-position four-way electromagnetic directional valve, the other three ports of the two-position four-way electromagnetic directional valve are connected with an oil return port of the oil tank, a rodless cavity liquid inlet and outlet port of the roller hydraulic cylinder and a rod cavity liquid inlet and outlet port of the roller hydraulic cylinder respectively, and the displacement sensor is arranged in the roller hydraulic cylinder. The real-time position of the hydraulic cylinder can be controlled by regulating and controlling the rotating speed of the servo motor, a high-cost servo valve used in the prior art is not needed, throttling loss of the servo valve in the working process is avoided, and the anti-pollution capacity of the system is improved.

Description

Technical Field

[0001] This utility model belongs to the technical field of electrode roll forming equipment, and particularly relates to an integrated lithium battery electrode roll forming machine pump-controlled direct drive hydraulic system. Background Technology

[0002] With the rapid development of new energy vehicles and energy storage industries, the requirements for electrode production precision in lithium battery manufacturing processes are becoming increasingly stringent. Electrode thickness consistency, as a core quality indicator, directly affects the cycle life, energy density, and safety performance of lithium batteries. As a key piece of equipment for electrode forming, the dynamic precision and stability of the hydraulic control system of the roller press have become a technical bottleneck restricting the improvement of battery manufacturing yield.

[0003] The hydraulic control systems of electrode roller presses both domestically and internationally are mainly based on valve-controlled cylinder structures. Electro-hydraulic servo valve control systems use electro-hydraulic servo valves as control elements to achieve high-precision control of hydraulic cylinders. The system consists of a hydraulic oil source, servo valves, hydraulic pipelines, sensors, and a controller. Although servo valve control systems offer high control precision, the throttling loss at the servo valve orifice leads to low system efficiency and significant power loss. Furthermore, servo valves have poor contamination resistance, require high oil cleanliness levels, and impose stringent requirements on equipment maintenance, making equipment operation and maintenance difficult. Utility Model Content

[0004] Based on this, and to address the aforementioned technical problems, an integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system is provided.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] An integrated direct-drive hydraulic system for a lithium battery electrode roll mill is characterized by comprising a servo motor, a hydraulic quantitative pump, a two-position four-way solenoid valve, and a displacement sensor. The output shaft of the servo motor is connected to the input shaft of the hydraulic quantitative pump. The inlet of the hydraulic quantitative pump is connected to the outlet of an oil tank. The outlet of the hydraulic quantitative pump is connected to one port of the two-position four-way solenoid valve. The other three ports of the two-position four-way solenoid valve are respectively connected to the return port of the oil tank, the rodless chamber inlet / outlet and the rod chamber inlet / outlet of the roll hydraulic cylinder, and the displacement sensor is located in the roll hydraulic cylinder.

[0007] This invention controls the real-time position of the hydraulic cylinder by adjusting the speed of the servo motor, eliminating the need for the high-cost servo valve used in existing technologies, avoiding the throttling losses of the servo valve during operation, and improving the system's anti-pollution capability. Attached Figure Description

[0008] Figure 1 This is a three-dimensional structural diagram of an embodiment of this application;

[0009] Figure 2 This is a schematic diagram of the connection structure of the fixed plate, servo motor, hydraulic quantitative pump and oil circuit integrated block in an embodiment of this application.

[0010] Figure 3 This is a schematic diagram of the structure of the oil circuit integrated block according to an embodiment of this application;

[0011] Figure 4 This is a schematic diagram of the structure of the fuel tank according to an embodiment of this application;

[0012] Figure 5 This is a schematic diagram of an embodiment of this application. Detailed Implementation

[0013] The embodiments of this utility model will be described below with reference to the accompanying drawings. It should be noted that the embodiments described in this specification are not exhaustive and do not represent the only embodiments of this utility model. The following corresponding embodiments are only for clearly illustrating the utility model content of this patent and are not intended to limit its implementation. For those skilled in the art, different variations and modifications can be made based on the described embodiments. Any obvious variations or modifications that fall within the technical concept and utility model content of this utility model are also within the protection scope of this utility model.

[0014] like Figure 5 As shown, in practical applications, the hydraulic system in this embodiment of the application consists of two sets, which are used to drive the pistons of the two sets of roller hydraulic cylinders 2 respectively, so that their piston rods rise and fall to drive the rollers 6 to roll the electrode sheet 5. The two sets of hydraulic systems are controlled by the controller 3 through two sets of servo drivers 4 respectively. The two sets of roller hydraulic cylinders 2 are used to roll the electrode sheet 5 on the operation side and the transmission side respectively.

[0015] like Figure 1 and Figure 3 As shown, the hydraulic system of this application embodiment includes a fixed plate 110, a servo motor 120, a hydraulic quantitative pump 130, an oil circuit integration block 140, an oil tank 150, a high-pressure filter 160, a two-position four-way solenoid directional valve 170, and an LVDT displacement sensor 180.

[0016] like Figure 2 As shown, the fixing plate 110 includes a first plate 111 and a second plate 112. The first plate 111 faces the front-to-back direction and is parallel to the oil inlet and outlet mounting surface (front side plane) of the roller hydraulic cylinder 2. The second plate 112 is arranged vertically, faces the left-to-right direction, and is fixed vertically and integrally with the first plate 111.

[0017] The servo motor 120 has an internal insertion structure and is arranged in the left-right direction. The end cover is fixed to the right side of the second plate 112 by bolts. The hydraulic quantitative pump 130 is a one-way gear pump, which is arranged in the left-right direction. It passes through the second plate 112 from the left side and is fixed to the end cover of the servo motor 120 by bolts. The input shaft of the hydraulic quantitative pump 130 is inserted into the housing of the servo motor 120 and directly connected to its output shaft. No coupling is required, which makes it easy to assemble and saves space and cost.

[0018] The oil outlet of the hydraulic quantitative pump 130 is connected to one end of the oil discharge pipeline 131.

[0019] The rear side of the oil circuit integration block 140 is fixed to the inlet and outlet mounting surfaces of the roller hydraulic cylinder 2 by bolts, and the front side is fixed to the first plate 111 by bolts.

[0020] like Figure 3 As shown, the oil circuit integration block 140 has a first pressure test connector 141, a first pressure sensor 142, a direct-acting relief valve 143, and a first hydraulic pipe connector 144 installed on its left side, and a second pressure test connector 145, a second pressure sensor 146, a second hydraulic pipe connector 147, and a one-way valve 148 installed on its right side. It has a first flow channel, a second flow channel, a third flow channel, a fourth flow channel, and a fifth flow channel inside.

[0021] The first hydraulic pipe connector 144 is connected to the other end of the oil drain pipe 131. The first hydraulic pipe connector 144 is connected to the inlet of the first flow channel. The first flow channel is divided into two paths via the check valve 148. One path is connected to the direct-acting relief valve 143, and the other path is connected to one port of the two-position four-way solenoid directional valve 170 via the high-pressure filter 160. The other three ports of the two-position four-way solenoid directional valve 170 are respectively connected to the inlets of the second flow channel, the third flow channel, and the fourth flow channel. The outlet of the second flow channel is connected to the second hydraulic pipe connector 147. The outlets of the third flow channel and the fourth flow channel are respectively connected to the rodless chamber inlet and outlet and the rod chamber inlet and outlet of the roll hydraulic cylinder 2 via the first pressure sensor 142 and the second pressure sensor 146.

[0022] The first pressure testing connector 141, the first pressure sensor 142, the second pressure testing connector 145, and the second pressure sensor 146 facilitate the detection of the pressure in the rodless chamber and the rod chamber of the roll hydraulic cylinder 2.

[0023] The fifth flow channel is connected between the third and fourth flow channels, and a throttling and pressure relief device 190 is provided on it. The throttling and pressure relief device 190 can be a damping plug, a throttling valve, or an overflow valve, etc.

[0024] like Figure 1As shown, the oil tank 150 is located above the hydraulic quantitative pump 130. The internal oil suction line is connected to the oil outlet through the oil filter. The oil outlet is connected to the oil inlet of the hydraulic quantitative pump 130 through the flange 190. The flange 190 can enhance the oil suction capacity of the hydraulic quantitative pump 130. At the same time, it also serves to fix the oil tank 140 to the hydraulic quantitative pump 130. The oil return port of the oil tank 150 is connected to one end of the oil return line 151, and the other end of the oil return line 151 is connected to the second hydraulic pipe joint 147.

[0025] In the above structure, the oil tank 150, servo motor 120, and hydraulic quantitative pump 130 are arranged longitudinally in space and are integrated on the roll hydraulic cylinder 2 through the oil circuit integration block 140, which occupies less space. At the same time, hydraulic valves and pressure sensors and other accessories are fixedly connected to the oil circuit integration block 140. The oil outlet of the hydraulic quantitative pump 130 is directly connected to the oil circuit integration block 140 through the oil outlet pipe 131, and the oil return pipe 151 of the oil tank 150 is directly connected to the oil circuit integration block 140. The remaining oil circuits are all integrated in the oil circuit integration block 140, forming an integrated hydraulic system without intermediate pipes, with a high degree of integration.

[0026] like Figure 4 As shown, the upper cover of the oil tank 150 is equipped with an air filter 152 and an integrated temperature and liquid level sensor 153. The rear side plate is fixed with a plate cooler 154 by bolts. The plate cooler 154 has a cavity, which is connected to the inside of the oil tank 150 through a pipe 154a. The oil return port of the oil tank 150 is formed on the upper surface of the plate cooler 154. Heat sinks can be installed on the plate cooler 154 to further improve the heat dissipation capacity.

[0027] like Figure 1 As shown, the LVDT displacement sensor 180 is installed on the roll hydraulic cylinder 2 to detect the piston displacement of the roll hydraulic cylinder 2.

[0028] The working principle of the hydraulic system in this embodiment is as follows:

[0029] like Figure 5 As shown, the hydraulic quantitative pump 130, driven by the servo motor 120, draws in low-pressure oil from the oil tank 150 and discharges high-pressure oil from its outlet. The high-pressure oil flows from the first hydraulic pipe joint 144 through the first flow channel to the check valve 148. The high-pressure oil flowing out of the check valve 148 flows back to the oil tank 150 through the direct-acting relief valve 143. The direct-acting relief valve 143 plays a safety protection role. Only when the system pressure exceeds the opening pressure of the relief valve will the high-pressure oil flow back to the oil tank through the relief valve. The other path enters the two-position four-way solenoid directional valve 170 through the high-pressure filter 160.

[0030] During the material change and lifting operation, the two-position four-way solenoid directional valve 170 is de-energized, and high-pressure oil enters the rodless chamber of the roll hydraulic cylinder 2, causing the piston of the roll hydraulic cylinder 2 to push the roll upward. Since the roll does not contact the lithium battery electrode 5 at this stage, the load force is the weight of the roll, the pressure difference between the two chambers of the hydraulic cylinder is small, and the oil does not flow through the fifth flow channel.

[0031] During the rolling operation, the rolls extrude the electrode sheet 5. The controller 3 controls the speed of the servo motor 120 through the servo driver 4 to maintain the position of the hydraulic cylinder. The controller 3 obtains the real-time displacement of the piston of the hydraulic cylinder 2 of the roll through the displacement sensor 180, compares the real-time displacement with the expected displacement, and controls the servo motor 120 to increase its speed when the real-time displacement is greater than the expected displacement. When the real-time displacement is less than the expected displacement, it controls the servo motor 120 to decrease its speed. When the real-time displacement is equal to the expected displacement, it controls the servo motor to maintain the current speed.

[0032] After testing, the piston position accuracy of the operating side hydraulic cylinder was basically maintained within ±0.4μm, with a peak error of 0.7μm, and the piston position accuracy of the transmission side hydraulic cylinder was basically maintained within ±0.3μm, with a peak error of 0.5μm. The piston of the hydraulic cylinder maintained its position well over a long period of time.

[0033] During this stage, the hydraulic cylinder 2 of the roll bears a large load, and the pressure difference between the two chambers of the hydraulic cylinder 2 is large. A small portion of the oil is used to replenish the internal leakage of the hydraulic cylinder, and the rest of the oil flows back to the oil tank 150 through the fifth flow channel. Due to the oil leakage of the fifth flow channel, the hydraulic quantitative pump 130 can be prevented from being in a low-speed state during the rolling operation, thus extending the service life of the hydraulic quantitative pump 130. At the same time, it can accelerate the circulation of the system oil and facilitate the system heat dissipation.

[0034] During the material changing and descent operation, the two-position four-way solenoid directional valve 170 is energized, and high-pressure oil enters the rod chamber of the roll hydraulic cylinder 2, causing the oil in the rodless chamber to flow back to the oil tank 150, and the hydraulic cylinder descends.

[0035] As can be seen from the above, the hydraulic system provided in this application embodiment can control the real-time position of the hydraulic cylinder by adjusting the speed of the servo motor. In the rolling operation, the speed of the servo motor is controlled according to the real-time displacement of the piston of the hydraulic cylinder of the roll, so that the piston of the hydraulic cylinder can be kept in the target position for a long time. It does not require the use of high-cost servo valves as in the prior art, avoids the throttling loss of the servo valve during operation, improves the system's anti-pollution capability, and improves system efficiency with low power loss.

[0036] Meanwhile, the system adopts an integrated design with a simple and highly integrated hydraulic circuit, which reduces installation costs and equipment maintenance costs.

[0037] In addition, the fifth flow channel can prevent the hydraulic metering pump from operating at low speed during the rolling process, thereby extending the service life of the hydraulic metering pump and accelerating the oil circulation in the system. Combined with the plate cooler of the oil tank, it achieves good heat dissipation and improves the reliability of the system.

[0038] Obviously, those skilled in the art should recognize that the above embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model. Any changes or modifications to the above embodiments within the essential spirit of the present utility model will fall within the scope of the claims of the present utility model.

Claims

1. An integrated direct-drive hydraulic system for a lithium battery electrode roll press, characterized in that, The device includes a servo motor, a hydraulic quantitative pump, a two-position four-way solenoid valve, and a displacement sensor. The output shaft of the servo motor is connected to the input shaft of the hydraulic quantitative pump. The inlet of the hydraulic quantitative pump is connected to the outlet of the oil tank. The outlet of the hydraulic quantitative pump is connected to one port of the two-position four-way solenoid valve. The other three ports of the two-position four-way solenoid valve are respectively connected to the return port of the oil tank, the rodless chamber inlet / outlet and the rod chamber inlet / outlet of the roll hydraulic cylinder, and the displacement sensor is located in the roll hydraulic cylinder.

2. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 1, characterized in that, It also includes an oil circuit integration block, which has a first flow channel, a second flow channel, a third flow channel, and a fourth flow channel. The servo motor, the hydraulic quantitative pump, the oil circuit integration block, and the oil tank are integrated and fixed on the inlet and outlet mounting surface of the roll hydraulic cylinder. The oil outlet of the hydraulic quantitative pump is connected to one port of the two-position four-way solenoid valve through the oil outlet pipeline and the first flow channel. The other three ports of the two-position four-way solenoid valve are connected to the return port of the oil tank, the rodless chamber inlet and outlet port and the rod chamber inlet and outlet port of the roll hydraulic cylinder through the second flow channel, the third flow channel, and the fourth flow channel, respectively.

3. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 2, characterized in that, The servo motor is connected to the oil circuit integration block via a fixing plate. The hydraulic quantitative pump is fixed to the end cover of the servo motor by bolts. The output shaft of the servo motor is directly connected to the input shaft of the hydraulic quantitative pump. The oil circuit integration block is connected to the inlet and outlet mounting surfaces by bolts.

4. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 3, characterized in that, The fixing plate includes a first plate parallel to the oil inlet / outlet mounting surface and a second plate fixed perpendicularly to the first plate. The second plate is arranged vertically. The first plate is fixed to the oil circuit integration block by bolts, and the servo motor is fixed perpendicularly to the second plate by bolts.

5. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 3, characterized in that, The oil tank is located above the hydraulic metering pump, and the oil inlet of the hydraulic metering pump is connected to the oil outlet of the oil tank via a flange.

6. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 2, characterized in that, The first flow channel is connected to the two-position four-way solenoid directional valve via a one-way valve and a high-pressure filter. The outlets of the third and fourth flow channels are respectively connected to the rodless chamber inlet and outlet and the rod chamber inlet and outlet of the roller hydraulic cylinder via a pressure sensor.

7. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 2, characterized in that, The oil circuit integrated block also has a fifth flow channel, which is connected between the third and fourth flow channels and is equipped with a throttling and pressure relief device.

8. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 7, characterized in that, The throttling and pressure relief device is a damping plug, a throttling valve, or an overflow valve.

9. The integrated lithium battery electrode roll press pump-controlled direct-drive hydraulic system according to claim 1, characterized in that, The upper cover of the oil tank is equipped with an air filter, an integrated temperature and liquid level sensor, and a plate cooler.

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