A Stop and Rewind Control Method Based on Strip Roll Welding

Abstract

This invention belongs to the field of battery cell tab rolling technology, specifically relating to a shutdown and rewind control method based on strip welding, comprising the following steps: S1, the control system issues a shutdown signal to cause the main traction shaft to move the strip at a uniform deceleration; S2, during deceleration, the cylinder-driven anvil lowers to disengage the strip from the welding shaft and stop the ultrasonic generator, thus completing the shutdown; S3, the strip is retracted a certain distance to rewind the main traction shaft to the corresponding position; S4, the main traction shaft and welding shaft are restarted to restart the strip movement; S5, during acceleration, the cylinder-driven anvil rises to bring the strip abutting against the welding shaft. When the real-time pressure detected by the pressure sensor reaches the target pressure, the ultrasonic generator is restarted to complete the restart; S6, the strip is driven and transmitted by the main traction shaft and ultrasonically rolled by the welding shaft.

Description

Technical Field

[0001] This invention belongs to the field of battery cell tab rolling technology, specifically relating to a shutdown and rewind control method based on strip rolling welding. Background Technology

[0002] In the process of welding multi-layer tabs for lithium batteries, ultrasonic roller welding technology is particularly important. It can not only effectively weld multi-layer tabs to ensure the electrical continuity and structural integrity of the battery, but also does not involve the melting of metal. Therefore, the internal resistance after welding is small and the conductivity is good, making it suitable for welding tabs of power batteries.

[0003] Ultrasonic roller welding equipment inevitably faces mid-process shutdowns, which can result in incomplete or missing welds. In such cases, rewinding is necessary. However, manual rewinding cannot accurately pinpoint the correct rewinding position, leading to excessive repeated welding. Since ultrasonic welding machines work by sending ultrasonic energy to strike the material strip, the already welded strip loses much of its ductility. Therefore, when restarting, the emitted ultrasonic energy, before the strip speed has increased, is concentrated on the previously welded area, easily causing burn-through or cracking, resulting in scrap material.

[0004] Therefore, it is necessary to improve the existing technology to overcome its shortcomings in practical applications. Summary of the Invention

[0005] Based on the aforementioned shortcomings and deficiencies in the prior art, one of the objectives of this invention is to at least solve one or more of the aforementioned problems in the prior art. In other words, one of the objectives of this invention is to provide a shutdown and rewind control method based on strip roller welding that meets one or more of the aforementioned requirements.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0007] This invention provides a shutdown and rewind control method based on strip roller welding, comprising the following steps:

[0008] S1. The control system sends a stop signal to cause the main traction shaft to start moving at a preset speed with uniform deceleration of the belt.

[0009] S2. During the deceleration process, the anvil is lowered by the cylinder linkage to disengage the material strip from the welding shaft and stop the ultrasonic generator to complete the shutdown.

[0010] S3. By controlling the conveyor belt to retract a certain distance, the main traction shaft is retracted to the corresponding position;

[0011] S4. Restart the movement of the main traction shaft and welding shaft to make the main traction shaft-linked conveyor belt start moving again;

[0012] S5. During the acceleration process, the anvil is raised by the cylinder linkage so that the anvil abuts the material strip against the welding shaft. When the pressure of the anvil reaches the welding pressure, the ultrasonic generator is restarted to complete the restart.

[0013] S6. The material belt is transmitted at a preset speed through the main traction shaft, and the material belt is ultrasonically rolled by the welding shaft.

[0014] As a preferred embodiment, the preset speed of the main traction shaft when it moves in conjunction with the conveyor belt is 50 to 150 m / min, and the rotational speed of the welding shaft is greater than that of the main traction shaft.

[0015] As a preferred embodiment, the main traction shaft and the welding shaft are equipped with absolute encoders.

[0016] As a preferred embodiment, the air pressure value when the cylinder linkage anvil moves is 0.15 to 0.3 MPa.

[0017] As a preferred embodiment, the distance the conveyor belt retracts in step S3 is:

[0018] S = P1 - P0 + S0

[0019] Where S represents the distance that needs to be rewound; P0 represents the position point of the absolute encoder of the main traction shaft when the anvil begins to fall and the anvil pressure is not up to standard when the machine stops; P1 represents the position point of the absolute encoder of the main traction shaft after the machine stops; S0 represents the distance traveled by the main traction shaft until the material belt starts ultrasonic rolling again.

[0020] As a preferred embodiment, in step S3, the welding shaft motion is restarted, and the distance by which the material strip is accelerated uniformly is:

[0021] (When V2+at1≤V1);

[0022] (When V2+at1>V1);

[0023] Where V1 represents the preset speed of the conveyor belt; a represents the acceleration set when the conveyor belt starts; V2 represents the set speed of the conveyor belt when the anvil starts to rise, and V2 < V1; t1 represents the time required for the anvil to rise to the target pressure value.

[0024] As a preferred embodiment, when the real-time pressure value detected by the pressure sensor reaches the target pressure value, the ultrasonic generator is restarted; when the real-time pressure value detected by the pressure sensor is less than 98% of the target pressure value, the ultrasonic generator is stopped.

[0025] As a preferred embodiment, the strip is configured as any one of copper foil, aluminum foil, or composite foil.

[0026] Compared with the prior art, the beneficial effects of this invention are:

[0027] This invention provides a shutdown and rewind control method based on strip roller welding. By rewinding the strip a certain distance, the distance and position of the rewind can be accurately determined, which can effectively ensure the normal welding of the strip when restarting after shutdown, avoid over-welding or weld penetration when the strip is repeatedly welded, and improve the welding quality of the strip. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a flowchart illustrating the shutdown and rewind control method based on strip roller welding according to an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the shutdown and rewind control system based on strip roller welding according to an embodiment of the present invention;

[0031] In the diagram: 1. Welding shaft, 2. Anvil, 3. Main traction shaft, 4. Material strip. Detailed Implementation

[0032] To more clearly illustrate the embodiments of this application, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0033] In the description of the embodiments of this application, the terms "upper," "lower," "front," "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," etc., are only used for distinction in description and have no special meaning.

[0034] According to some embodiments of this application, please refer to Figures 1 to 2 As shown, a shutdown and rewind control method based on strip roller welding is provided, including the following steps:

[0035] S1. The control system sends a stop signal to cause the main traction shaft to start moving at a preset speed with uniform deceleration of the belt.

[0036] Specifically, welding shaft 1 and main traction shaft 3 convey the material belt at a preset speed V1. When the control system issues a stop signal, the main traction shaft begins to decelerate uniformly, thus uniformly decelerating the material belt to zero. The preset speed of the material belt moving with the main traction shaft is 50-150 m / min, preferably set to 50 m / min.

[0037] Because the ultrasonic rolling process hammers and stretches the material belt, the welding shaft travels a slightly longer distance on the material belt than the material belt travels within the same time frame. Therefore, the rotation speed of the welding shaft is slightly higher than that of the main traction shaft to ensure normal material belt conveying. The specific speed can vary depending on the material of the material belt's tabs.

[0038] S2. During deceleration, the cylinder-linked anvil falls to disengage the strip from the welding shaft and stop the ultrasonic generator, thus completing the shutdown.

[0039] During the uniform deceleration of the conveyor belt, when V1 decelerates to 10m / min, the cylinder-linked anvil begins to fall, and the anvil-linked conveyor belt disengages from the welding shaft. When the pressure sensor of the anvil returns a pressure lower than 1960N, the ultrasonic generator stops working until the speed of V1 drops to zero.

[0040] During the uniform deceleration of the conveyor belt, the value of the absolute encoder is read by the servo driver, and the position point P0 of the absolute encoder of the main traction shaft when the pressure of the anvil is not up to standard and the position point P1 of the absolute encoder of the main traction shaft when the machine stops are completed are recorded.

[0041] S3. By controlling the conveyor belt to retract a certain distance, the main traction shaft is retracted to the corresponding position.

[0042] Specifically, the distance the conveyor belt retracts in step S3 is:

[0043] S = P1 - P0 + S0

[0044] Where S represents the distance that needs to be rewound; P0 represents the position point of the absolute encoder of the main traction shaft when the anvil begins to fall and the anvil pressure is not up to standard when the machine stops; P1 represents the position point of the absolute encoder of the main traction shaft after the machine stops; S0 represents the distance that the main traction shaft travels from the point where the material belt starts moving again until the welding shaft starts ultrasonic rolling, which is also the distance that the material belt needs to travel during the uniform acceleration process.

[0045] Furthermore, since ultrasonic energy is still transmitted between the welding shaft and the strip during the shutdown process, the distance P1-P0 is also the distance at which the strip will have a poor weld during the shutdown process.

[0046] Furthermore, in step S3, the welding shaft motion is restarted, and the distance by which the material strip is uniformly accelerated is:

[0047] (When V2+at1≤V1);

[0048] (When V2+at1>V1);

[0049] Where V1 represents the preset speed of the conveyor belt; a represents the acceleration set when the conveyor belt starts; V2 represents the set speed of the conveyor belt when the anvil starts to rise, and V2 < V1; t1 represents the time required for the anvil to rise to the target pressure value.

[0050] S4. Restart the movement of the main traction shaft and welding shaft so that the main traction shaft can start moving the conveyor belt again.

[0051] Once the position of the rewind belt is determined, the control system sends a start signal to restart the machine and start the rotation of the main traction shaft and welding shaft. The main traction shaft begins to accelerate uniformly, so that the material belt is accelerated uniformly from the initial speed of zero to the preset speed V1.

[0052] S5. During acceleration, the anvil is raised by the cylinder linkage so that the anvil abuts the material strip against the welding shaft. When the real-time pressure detected by the pressure sensor reaches the target pressure, the ultrasonic generator is restarted to complete the restart.

[0053] During the uniform acceleration of the conveyor belt, when the conveyor belt speed reaches V2, the cylinder-linked anvil begins to rise, and the anvil links the conveyor belt to abut the welding shaft. When the pressure feedback from the pressure sensor of the anvil is greater than or equal to the target pressure value of 2000N, the ultrasonic generator starts to work until the speed accelerates to V1 to complete the restart process.

[0054] Furthermore, when the real-time pressure value detected by the pressure sensor reaches the target pressure value, the ultrasonic generator is restarted; when the real-time pressure value detected by the pressure sensor is less than 98% of the target pressure value, the ultrasonic generator is stopped.

[0055] Furthermore, during uniform acceleration, V2 is set to 5 m / min, and the air pressure during cylinder linkage anvil movement is 0.15–0.3 MPa, preferably 0.3 MPa.

[0056] S6. The material belt is transmitted at a preset speed through the main traction shaft, and the material belt is ultrasonically rolled by the welding shaft.

[0057] Once the material belt is accelerated to a preset speed V1, it is conveyed at that speed at a constant speed to achieve ultrasonic rolling of the welding shaft onto the material belt.

[0058] In the embodiments of this application, the material strip can be configured as any one of copper foil, aluminum foil or composite foil, and the specific selection can be made according to actual needs.

[0059] According to some embodiments of this application, a shutdown and rewind control method based on strip roller welding is provided. By rewinding the strip a certain distance, the distance and position of the rewinding can be accurately determined, which can effectively ensure the normal welding of the strip when restarting after shutdown, avoid over-welding or weld penetration when the strip is repeatedly welded, and improve the welding quality of the strip.

[0060] Accordingly, such as Figure 2 The schematic diagram of the shutdown and rewind control system based on strip roller welding of this application embodiment is shown. The welding shaft 1 and the anvil 2 are respectively abutted against the upper and lower sides of the strip 4 to roll the strip 4. The main traction shaft 3 provides the power source for the strip conveying.

[0061] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0062] The above description is only a detailed explanation of the preferred embodiments and principles of this application. For those skilled in the art, there may be changes in the specific implementation based on the ideas provided by this invention, and these changes should also be considered within the scope of protection of this application.

Claims

1. A method for controlling machine shutdown and rewinding based on strip roller welding, characterized in that, Includes the following steps: S1. The control system sends a stop signal to cause the main traction shaft to start moving at a preset speed with uniform deceleration of the belt. S2. During the deceleration process, the anvil is lowered by the cylinder linkage to disengage the material strip from the welding shaft and stop the ultrasonic generator to complete the shutdown. S3. By controlling the conveyor belt to retract a certain distance, the main traction shaft is retracted to the corresponding position; The distance the conveyor belt retracts in step S3 is: S = P1 - P0 + S0 Where S represents the distance that needs to be rewound; P0 represents the position point of the absolute encoder of the main traction shaft when the anvil begins to fall and the anvil pressure is not up to standard when the machine stops; P1 represents the position point of the absolute encoder of the main traction shaft after the machine stops; S0 represents the distance traveled by the main traction shaft until the material belt starts ultrasonic rolling again. In step S3, the welding shaft motion is restarted, and the distance by which the material strip is accelerated uniformly is: (When V2+at1≤V1); (When V2+at1>V1); Where V1 represents the preset speed of the conveyor belt; a represents the acceleration set when the conveyor belt starts; V2 represents the set speed of the conveyor belt when the anvil starts to rise, and V2 < V1; t1 represents the time required for the anvil to rise to the target pressure value. S4. Restart the movement of the main traction shaft and welding shaft to make the main traction shaft-linked conveyor belt start moving again; S5. During the acceleration process, the anvil is raised by the cylinder linkage so that the anvil abuts the material strip against the welding shaft. When the real-time pressure detected by the pressure sensor reaches the target pressure, the ultrasonic generator is restarted to complete the restart. S6. The material belt is transmitted at a preset speed through the main traction shaft, and the material belt is ultrasonically rolled by the welding shaft.

2. The method for stopping and rewinding control based on strip roller welding according to claim 1, characterized in that, The preset speed of the main traction shaft when it moves in conjunction with the conveyor belt is 50-150 m / min, and the rotational speed of the welding shaft is greater than that of the main traction shaft.

3. The method for stopping and rewinding control based on strip roller welding according to claim 1, characterized in that, The main traction shaft and the welding shaft are equipped with absolute encoders.

4. The method for stopping and rewinding control based on strip roller welding according to claim 1, characterized in that, The air pressure value when the cylinder linkage anvil moves is 0.15 to 0.3 MPa.

5. The method for stopping and rewinding control based on strip roller welding according to claim 1, characterized in that, When the real-time pressure value detected by the pressure sensor reaches the target pressure value, the ultrasonic generator is restarted; when the real-time pressure value detected by the pressure sensor is less than 98% of the target pressure value, the ultrasonic generator is stopped.

6. The method for stopping and rewinding control based on strip roller welding according to claim 1, characterized in that, The strip is configured as any one of copper foil, aluminum foil, or composite foil.

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