An automatic wet weight weighing device for screen-printed silver paste in batteries

Abstract

This utility model relates to the field of photovoltaic cell screen printing technology, specifically an automatic wet weight weighing device for silver paste in cell screen printing. It includes two symmetrically distributed conveyor belts, each with a weighing device inside. Each weighing device includes a base symmetrically arranged on both sides of the conveyor belt, with a housing movably connected to the upper surface of the base. It also includes a spring installed inside the base, with a pressure sensor connected to one end and a pressure plate connected to the other. The spring initially applies a preload, lifting the pressure plate upwards to maintain constant pressure contact with the lower surface of the conveyor belt. Through the dual weighing units built into the conveyor belt—the first and second weighing devices—continuous and uninterrupted weighing of the cells before and after printing is achieved, avoiding production line interruptions. Real-time output of weight data before and after printing is provided, enabling real-time monitoring of silver paste consumption.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic cell screen production technology, specifically an automatic weighing device for wet weight of silver paste in cell screens. Background Technology

[0002] Screen printing technology is a key process for forming battery electrodes. Meanwhile, silver paste represents the largest non-silicon cost component of photovoltaic cells. The lifespan of the squeegee and screen, as well as the amount of silver paste consumed, are significant factors affecting the manufacturing cost and efficiency of solar cells. Furthermore, under the same machine parameters, different squeegee and screen lifespans result in significantly different silver paste consumption.

[0003] Currently, silver paste consumption is measured manually, which is slow. After parameters are changed, manual measurement cannot promptly determine the corresponding amount of silver paste used, resulting in too much or too little silver paste on the surface of the produced cells, affecting product quality and increasing costs. Furthermore, manual measurement also suffers from large test data errors and the inability to increase the testing frequency, making it impossible to quickly adjust the silver paste supply system and leading to a large number of defective products. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes an automatic wet weight weighing device for screen-printed silver paste in batteries.

[0005] An automatic wet weight weighing device for screen printing silver paste of batteries includes two symmetrically distributed conveyor belts. Weighing devices are installed inside the conveyor belts, including a first weighing device and a second weighing device. The first weighing device is responsible for the first weighing, and the second weighing device is responsible for the weighing after the battery is printed. This enables uninterrupted weighing of the battery cells during the conveying process, avoiding production line interruptions. The weighing device includes a base symmetrically arranged on both sides of the conveyor belt, and a shell is movably connected to the upper surface of the base.

[0006] It also includes a spring installed inside the base, with a pressure sensor connected to one end and a pressure plate connected to the other end. The spring initially applies preload, lifting the pressure plate upwards to maintain constant pressure contact with the lower surface of the conveyor belt; this eliminates measurement gaps caused by conveyor belt vibration, while the preload counteracts the conveyor belt's own weight sagging, ensuring a stable zero-position signal reference.

[0007] Furthermore, the spring adopts a variable pitch helical spring, with low stiffness in the initial section to buffer the impact force and high stiffness in the final section to ensure linear transmission.

[0008] Furthermore, pressure sensors are arranged along the four corners of the pressure plate. When the battery cells are misaligned, the sum of the values ​​at the four corners remains constant, improving detection accuracy. Furthermore, the differential outputs of the four sensors cancel out noise from vibrations at the same frequency, avoiding interference from conveyor belt vibrations. Furthermore, even if one sensor fails, the remaining three can still perform weighing operations.

[0009] Furthermore, the housing includes a first plate-shaped portion, the surface of which is provided with a mounting groove that completely penetrates the first plate-shaped portion and extends downward into the interior of the base. The pressure sensor is located at the bottom of the mounting groove, and the spring is installed inside the mounting groove.

[0010] Furthermore, a third plate and a fourth plate are fixedly connected to the upper surfaces of both ends of the first plate-shaped part. The surfaces of the third plate and the fourth plate-shaped part near the mounting groove are provided with sliding grooves, and sliding blocks are fitted into the sliding grooves. The sliding blocks are set on the lateral surface of the pressure plate.

[0011] Furthermore, the slide groove is fitted with a self-lubricating bushing; the depth of the slide groove is greater than the height of the slider, allowing the pressure plate to move vertically. The slide groove, in conjunction with the slider, restricts the pressure plate to move only vertically, preventing lateral forces from interfering with the weighing.

[0012] Furthermore, self-lubricating bushings reduce frictional losses and extend service life.

[0013] Furthermore, a second plate is connected between the third and fourth plate sections. The second plate, together with the third and fourth plate sections, forms a semi-enclosed protective structure, creating a protective shield to prevent silver paste splashing and dust from entering the weighing unit, thus ensuring the sensor can operate stably for a long time in a highly polluted printing environment.

[0014] Furthermore, a low-friction layer is provided on the upper surface of the pressure plate. The surface of the pressure plate is covered with a polytetrafluoroethylene coating to reduce the dynamic friction coefficient with the conveyor belt and prevent weighing drift caused by friction deformation or slippage of the conveyor belt.

[0015] Furthermore, a rotating platform is provided between the conveyor belts, and multiple worktables are provided on the upper surface of the rotating platform, with the worktables evenly distributed along the circumference of the rotating platform.

[0016] Furthermore, the central axis of the rotary table is perpendicular to the conveyor belt's transport direction, and the rotary table can rotate intermittently around its own axis, allowing each workstation to sequentially dock with the conveyor belt. The intermittent rotation of the rotary table enables the feeding, printing, weighing, and discharging stations to operate in a cyclical manner; the weighing station automatically docks with the conveyor belt, achieving fully automated operation and further improving work efficiency.

[0017] Furthermore, the conveyor belt needs to work in conjunction with the rotary table for printing operations. Therefore, when the conveyor belt transports the battery cells, it makes the battery cells pass over the weighing device in sequence and stay for a time t, where time t is the time of the rotary table's rotation position, thus reducing the influence of the battery cells' own inertia during weighing.

[0018] Compared with existing technologies, this utility model has the following advantages: Through the dual weighing units built into the conveyor belt, the first and second weighing devices enable continuous, uninterrupted weighing of the battery cells before and after printing, avoiding production line interruptions. Real-time output of weight data before and after printing allows for real-time monitoring of silver paste consumption. The use of pre-tensioning springs, four-corner differential sensors, and a slider guide structure counteracts conveyor belt vibration and lateral force interference, ensuring weighing accuracy. Instantaneous silver paste consumption data is automatically fed back to the printing system, allowing for timely adjustment of scraper pressure and silver paste supply, reducing the defect rate due to excessive or insufficient surface paste, thus contributing to cost control. The semi-enclosed protective cover and low-friction coating design ensure long-term stable operation of the sensors in a silver paste-contaminated environment, further enhancing the system's reliability. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram showing the location of the automatic weighing device installed on the conveyor belt;

[0021] Figure 2 This is a cross-sectional view of the automatic weighing device installed on the conveyor belt;

[0022] Figure 3 This is a cross-sectional view (b) of the automatic weighing device installed on the conveyor belt.

[0023] Figure 4 Top view of an automatic weighing device installed on a conveyor belt;

[0024] Figure 5 This is a schematic diagram of the base and outer shell structure.

[0025] In the picture:

[0026] 1. Conveyor belt;

[0027] 2. First weighing device; 201. Base; 202. Outer shell; 203. Pressure plate; 204. Pressure sensor; 205. Spring; 206. Slide groove; 207. Sliding block;

[0028] 208. Low-friction layer; 209. Mounting groove;

[0029] 3. Second weighing device;

[0030] 4. Rotary table;

[0031] 5. Printing workbench;

[0032] 6. Feeding workbench;

[0033] 7. Buffer worktable;

[0034] 8. Discharge workbench;

[0035] 9. The first plate-like part;

[0036] 10. The second plate-like part;

[0037] 11. Third plate-like part;

[0038] 12. Fourth plate-like part. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] The application principle of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0041] Example 1

[0042] like Figure 1-3 As shown, an automatic wet weight weighing device for screen printing silver paste of batteries includes two symmetrically distributed conveyor belts 1. The conveyor belts 1 are equipped with weighing devices, including a first weighing device 2 and a second weighing device 3. The first weighing device 2 is responsible for the first weighing, and the second weighing device 3 is responsible for the weighing after the battery panels are printed, so as to realize the uninterrupted weighing of the battery cells during the conveying process and avoid production line interruption. The weighing device includes a base 201 symmetrically arranged on both sides of the conveyor belt 1, and a shell 202 is movably connected to the upper surface of the base 201.

[0043] It also includes a spring 205 disposed inside the base 201. One end of the spring 205 is connected to a pressure sensor 204, and the other end is connected to a pressure plate 203. In its initial state, the spring applies a preload, lifting the pressure plate 203 upwards to maintain constant pressure contact with the lower surface of the conveyor belt 1; this eliminates the measurement gap caused by conveyor belt vibration, while the preload counteracts the sagging of the conveyor belt due to its own weight. This ensures a stable zero-position signal reference.

[0044] Spring 205 is a variable pitch helical spring. The initial section has low stiffness to buffer impact force, while the final section has high stiffness to ensure linear transmission.

[0045] Example 2

[0046] like Figure 1-5As shown, an automatic wet weight weighing device for screen printing silver paste of batteries includes two symmetrically distributed conveyor belts 1. The conveyor belts 1 are equipped with weighing devices, including a first weighing device 2 and a second weighing device 3. The first weighing device 2 is responsible for the first weighing, and the second weighing device 3 is responsible for the weighing after the battery panels are printed, so as to realize the uninterrupted weighing of the battery cells during the conveying process and avoid production line interruption. The weighing device includes a base 201 symmetrically arranged on both sides of the conveyor belt 1, and a shell 202 is movably connected to the upper surface of the base 201.

[0047] It also includes a spring 205 disposed inside the base 201. One end of the spring 205 is connected to a pressure sensor 204, and the other end is connected to a pressure plate 203. In its initial state, the spring applies a preload, lifting the pressure plate 203 upwards to maintain constant pressure contact with the lower surface of the conveyor belt 1; this eliminates the measurement gap caused by conveyor belt vibration, while the preload counteracts the sagging of the conveyor belt due to its own weight. This ensures a stable zero-position signal reference.

[0048] Spring 205 is a variable pitch helical spring. The initial section has low stiffness to buffer impact force, while the final section has high stiffness to ensure linear transmission.

[0049] The pressure sensors 204 are arranged at the four corners of the pressure plate 203. When the battery cells are placed off-center, the sum of the values ​​at the four corners remains constant, improving the detection accuracy. Furthermore, the differential output of the four sensors cancels out the noise of vibration at the same frequency, avoiding interference from the vibration of the conveyor belt 1. Furthermore, if a single sensor is damaged, the other three can still perform weighing operations.

[0050] The outer casing 202 includes a first plate-shaped portion 9, on the surface of which a mounting groove 209 is formed. The mounting groove 209 completely penetrates the first plate-shaped portion 9 and extends downward into the base 201. The pressure sensor 204 is located at the bottom of the mounting groove 209, and the spring 205 is installed in the mounting groove 209.

[0051] The upper surfaces of the first plate-shaped part 9 are fixedly connected to the third plate-shaped part 11 and the fourth plate-shaped part 12. The surfaces of the third plate-shaped part 11 and the fourth plate-shaped part 12 near the mounting groove 209 are provided with sliding grooves 206. The sliding grooves 206 are fitted with sliders 207, which are disposed on the lateral surface of the pressure plate 203.

[0052] The slide groove 206 is embedded with a self-lubricating bushing; the depth of the slide groove 206 is greater than the height of the slider 207, allowing the pressure plate 203 to move vertically. The slide groove 206, in conjunction with the slider 207, restricts the pressure plate to move only vertically, avoiding lateral forces from interfering with the weighing.

[0053] Self-lubricating bushings reduce frictional loss and extend service life.

[0054] A second plate 10 is connected between the third plate 11 and the fourth plate 12. The second plate 10, together with the third plate 11 and the fourth plate 12, forms a semi-enclosed protective structure, forming a protective cover to prevent silver paste splashing and dust from entering the weighing unit; ensuring that the sensor can work stably for a long time in a highly polluted printing environment.

[0055] The upper surface of the pressure plate 203 is provided with a low-friction layer 208. The surface of the pressure plate is covered with a polytetrafluoroethylene coating to reduce the dynamic friction coefficient with the conveyor belt and prevent weighing drift caused by friction deformation or slippage of the conveyor belt.

[0056] A rotary table 4 is provided between the conveyor belts 1. Multiple worktables are provided on the upper surface of the rotary table 4, and the worktables are evenly distributed along the circumference of the rotary table 4. The worktables include a printing worktable, a feeding worktable, a buffer worktable, and a discharging worktable; the worktable located at the printing position is called the printing worktable, the worktables located at the inlet and outlet of the conveyor belt are called the feeding worktable and the discharging worktable, and the remaining positions are called buffer worktables.

[0057] The central axis of the rotary table 4 is perpendicular to the conveying direction of the conveyor belt 1, and the rotary table 4 can rotate intermittently around its own axis, so that each workbench connects to the conveyor belt 1 in sequence. The intermittent rotation of the rotary table enables the feeding, printing, weighing, and discharging stations to operate in a cyclical manner; the weighing station automatically connects to the conveyor belt, realizing unmanned operation of the entire process and further improving work efficiency.

[0058] Example 3

[0059] When the automatic wet weight weighing device for screen printing silver paste of a battery starts working, the unprinted battery cell substrate is conveyed to the weighing area by conveyor belt 1. When the substrate completely covers the pressure plate (203), the weight of the battery cell 1 passes through the pressure plate 203 and compresses the spring 205. The pressure sensor 204 detects the change in spring force, outputs the change data, and obtains the initial weight. The battery cell enters the worktable on the rotary table 4 for printing. After printing is completed, it enters the next conveyor belt and repeats the above weighing process to obtain the second weight. The difference between the two sets of data is the silver paste consumption. The production line is adjusted in real time according to the silver paste consumption to improve the response speed of the production line.

[0060] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0061] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An automatic wet weight weighing device for screen-printed silver paste in batteries, characterized in that: It includes two sets of symmetrically distributed conveyor belts (1), and a weighing device is provided inside the conveyor belt (1). The weighing device includes a base (201) symmetrically arranged on both sides of the conveyor belt (1), and a shell (202) is movably connected to the upper surface of the base (201). It also includes a spring (205) disposed inside the base (201), one end of which is connected to a pressure sensor (204) and the other end is connected to a pressure plate (203), the upper surface of which abuts against the lower surface of the conveyor belt (1).

2. The automatic wet weight weighing device for screen-printed silver paste of a battery according to claim 1, characterized in that: The outer casing (202) includes a first plate-shaped portion (9), on which a mounting groove (209) is provided. The mounting groove (209) completely penetrates the first plate-shaped portion (9) and extends downward into the base (201). The pressure sensor (204) is located at the bottom of the mounting groove (209), and the spring (205) is installed in the mounting groove (209).

3. The automatic wet weight weighing device for screen-printed silver paste of a battery according to claim 2, characterized in that: The upper surfaces of the first plate-shaped part (9) are fixedly connected to the third plate-shaped part (11) and the fourth plate-shaped part (12). The surfaces of the third plate-shaped part (11) and the fourth plate-shaped part (12) near the mounting groove (209) are provided with sliding grooves (206). The sliding grooves (206) are fitted with sliders (207). The sliders (207) are disposed on the lateral surface of the pressure plate (203).

4. The automatic wet weight weighing device for screen-printed silver paste of a battery according to claim 3, characterized in that: The groove (206) is fitted with a self-lubricating bushing; the depth of the groove (206) is greater than the height of the slider (207), so that the pressure plate (203) can be displaced in the vertical direction.

5. The automatic wet weight weighing device for screen-printed silver paste of a battery according to claim 3, characterized in that: A second plate (10) is connected between the third plate (11) and the fourth plate (12), and the second plate (10), together with the third plate (11) and the fourth plate (12), form a semi-enclosed protective structure.

6. The automatic wet weight weighing device for screen-printed silver paste of a battery according to claim 1, characterized in that: A low-friction layer (208) is provided on the upper surface of the pressure plate (203).

7. The automatic wet weight weighing device for screen-printed silver paste of a battery according to claim 1, characterized in that: A rotating platform (4) is provided between the conveyor belts (1). Multiple worktables are provided on the upper surface of the rotating platform (4). The worktables are evenly distributed along the circumference of the rotating platform (4).

8. The automatic wet weight weighing device for screen-printed silver paste of a battery according to claim 7, characterized in that: The central axis of the rotary table (4) is perpendicular to the conveying direction of the conveyor belt (1), and the rotary table (4) can rotate intermittently around its own axis so that each workbench connects with the conveyor belt (1) in sequence.

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