Series welding device and series welding method for photovoltaic cells

Abstract

The invention discloses a series welding device and method for photovoltaic cells. The series welding method comprises the steps that the photovoltaic cells are placed on a workbench; pulling out a special-shaped welding strip above the photovoltaic cell, wherein the special-shaped welding strip comprises a circular section and a non-circular section which are connected with each other; the two ends of the non-circular section are clamped, and at least one end of the non-circular section is stretched; the special-shaped welding strip is cut off, and the circular section is arranged on the surface of one photovoltaic cell; and the other photovoltaic cell piece is arranged on the non-circular section. Therefore, when the special-shaped welding strip is placed on the photovoltaic cell, the welding strip of the non-circular section is in contact with the edge of the photovoltaic cell, so that the welding strip of the circular section and the welding strip of the non-circular section can be prevented from being stretched, and the situation that the circular section extends out of the edge of the photovoltaic cell during cutting and is broken when abutting against the edge of the photovoltaic cell is avoided; the possibility of photovoltaic cell cracking is reduced, the yield of products is improved, and the production cost and the waste of raw materials are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic component processing, and in particular to a photovoltaic cell string welding device and a string welding method. Background Art

[0002] In the prior art, in order to reduce the obstruction of the surface of photovoltaic cells by welding ribbons, the industry has gradually begun to use special-shaped welding ribbons to connect adjacent photovoltaic cells. The so-called special-shaped welding ribbon has two integrally connected welding ribbon segments with different cross-sectional areas. Among them, the welding ribbon segment connected to the front of the cell usually adopts a circular cross-section (that is, called a circular segment) to reduce the obstruction of the light-receiving area, and the welding ribbon segment connected to the back of the cell usually adopts a flat cross-section (that is, called a non-circular segment) to achieve reliable welding and fixation with the back of the cell. In the string welding process of photovoltaic cells, it is necessary to combine the welding ribbon with the cell and use the welding ribbon to connect the cell in series. For the stretching of the special-shaped welding ribbon, the clamping mechanism and the stretching mechanism are generally arranged at both ends of the special-shaped welding ribbon, that is, the stretching mechanism is clamped at one end of the flat section, and the clamping mechanism is clamped at one end of the round wire section. Therefore, when the stretching mechanism stretches the special-shaped welding ribbon, the round wire section will also be stretched, and it will be more easily stretched and elongated than the flat section welding ribbon, so that the end of the round wire section is easy to exceed the edge of the cell, resulting in the cell edge being easily compressed and broken in the subsequent lamination process, affecting the yield of the product. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a method for serially welding photovoltaic cells, which can improve the problem of cell splitting caused by lamination of welding ribbons and cells.

[0004] Another object of the present invention is to provide a photovoltaic cell string welding device for use in the above-mentioned string welding method.

[0005] The method for string welding of photovoltaic cells according to an embodiment of the present invention comprises: placing a photovoltaic cell on a workbench; pulling out a special-shaped welding ribbon above the photovoltaic cell, wherein the special-shaped welding ribbon comprises a circular segment and a non-circular segment connected to each other; clamping the two ends of the non-circular segment, and stretching at least one end of the non-circular segment; cutting off the special-shaped welding ribbon and placing the circular segment on the surface of one photovoltaic cell; and placing another photovoltaic cell on the non-circular segment.

[0006] According to the method for string welding of photovoltaic cells according to the embodiment of the present invention, by stretching only the non-circular segment so that when the special-shaped welding strip is placed on the photovoltaic cell, the welding strip of the non-circular segment contacts the edge of the photovoltaic cell, thereby avoiding stretching of both the circular segment and the non-circular segment welding strip, avoiding the circular segment extending out of the edge of the photovoltaic cell during cutting and causing breakage when it stops at the edge of the photovoltaic cell, reducing the possibility of photovoltaic cell splitting, improving product yield, and reducing production costs and waste of raw materials.

[0007] The special-shaped welding strip is processed by a welding strip stretching device, and the welding strip stretching device includes: a clamping mechanism and a stretching mechanism. The string welding method also includes: the clamping mechanism and the stretching mechanism work, the clamping mechanism is suitable for clamping an end of the non-circular segment adjacent to the circular segment, the clamping mechanism clamps an end of the non-circular segment away from the circular segment, and the stretching mechanism stretches the non-circular segment toward the end away from the clamping mechanism; after the special-shaped welding strip is stretched, the clamping mechanism and the stretching mechanism release the special-shaped welding strip.

[0008] The welding ribbon stretching device also includes: a traction mechanism, and the string welding method also includes: before the special-shaped welding ribbon is stretched, the traction mechanism moves to the free end of the special-shaped welding ribbon, the traction mechanism is suitable for clamping the free end of the special-shaped welding ribbon and pulling the special-shaped welding ribbon out of the welding ribbon reel for a predetermined distance and then stops working; when the traction mechanism pulls the special-shaped welding ribbon to move, the clamping mechanism and the stretching mechanism are in a released state of releasing the special-shaped welding ribbon.

[0009] After the special-shaped welding strip is stretched by the stretching mechanism for a predetermined distance, the traction mechanism starts to work, and after the special-shaped welding strip continues to move forward by the distance of one of the circular segments and one of the non-circular segments under the traction of the traction mechanism, the traction mechanism stops working.

[0010] The welding strip stretching device also includes: a cutting mechanism, and the string welding method further includes: after the special-shaped welding strip of a complete cycle formed by the circular segment and the non-circular segment is stretched, the traction mechanism pulls the special-shaped welding strip forward to the end of the non-circular segment in the complete cycle away from the circular segment and opposite to the cutting mechanism.

[0011] When the cutting mechanism is opposite to the end of the non-circular segment away from the circular segment, the cutting mechanism cuts the end of the non-circular segment away from the circular segment, so that a complete cycle of the special-shaped welding ribbon is detached from the welding ribbon reel.

[0012] The welding strip stretching device further comprises: an identification mechanism, which controls the cutting mechanism to cut the special-shaped welding strip when the identification mechanism identifies that one end of the non-circular segment away from the circular segment is opposite to the cutting mechanism.

[0013] After the cutting mechanism cuts a complete cycle of the special-shaped welding strip, the traction mechanism returns to the cutting position to re-clamp the end of the special-shaped welding strip and moves forward a predetermined distance to start processing the next complete cycle of the special-shaped welding strip; wherein, when the traction mechanism is traction of the special-shaped welding strip, the stretching mechanism and the clamping mechanism are both in a loose state to allow the special-shaped welding strip to pass through the clamping mechanism and the stretching mechanism.

[0014] A photovoltaic cell string welding device, the photovoltaic cell string welding device is suitable for processing special-shaped welding strips in any of the photovoltaic cell string welding methods described above, the welding device comprises: a welding strip stretching device, the welding strip stretching device comprises a clamping mechanism and a stretching mechanism, the clamping mechanism and the stretching mechanism are arranged at intervals, the clamping mechanism is suitable for being arranged at an end of the non-circular segment of the special-shaped welding strip adjacent to the circular segment of the special-shaped welding strip, and the stretching mechanism is suitable for being arranged at an end of the non-circular segment away from the circular segment.

[0015] The clamping mechanism comprises: a base and a clamping member, wherein the base is arranged on a workbench; the clamping member is arranged on the base, and the clamping member is used to clamp the non-circular segment of the special-shaped welding strip adjacent to the end of the circular segment of the special-shaped welding strip; when the special-shaped welding strip needs to be stretched, the clamping member is suitable for clamping the end of the non-circular segment adjacent to the circular segment, and the stretching mechanism stretches the non-circular segment at the end of the non-circular segment away from the circular segment toward a direction away from the clamping mechanism.

[0016] The photovoltaic cell string welding device further includes: a moving mechanism, which is arranged between the base and the clamping member, and the two ends of the moving mechanism are respectively connected to the clamping member and the base, and the moving mechanism is used to drive the clamping member to move relatively close to and away from the stretching mechanism to adjust the clamping position of the clamping mechanism.

[0017] The photovoltaic cell string welding device also includes: a second clamping mechanism, which is arranged between the traction mechanism of the welding strip stretching device and the clamping mechanism, and clamps the stretched special-shaped welding strip when the cutting mechanism of the welding strip stretching device cuts the special-shaped welding strip to prevent it from falling off.

[0018] The yield strength of the non-circular segment is greater than the yield strength of the circular segment.

[0019] The cross-sectional shape of the circular segment is different from the cross-sectional shape of the non-circular segment.

[0020] The cross-sectional shape of the non-circular segment is flat.

[0021] The special-shaped welding strip includes a plurality of circular segments and a plurality of non-circular segments, and the plurality of circular segments and the plurality of non-circular segments are staggered and connected along the length direction.

[0022] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0024] Figure 1 is a schematic diagram of a welding strip stretching device according to an embodiment of the present invention.

[0025] Figure 2 is a schematic diagram of a moving mechanism according to an embodiment of the present invention.

[0026] Figure 3 It is a schematic diagram of the movement of the traction mechanism clamping the special-shaped welding strip according to an embodiment of the present invention.

[0027] Figure 4 Schematic diagram of a special-shaped welding strip after being stretched according to an embodiment of the present invention.

[0028] Figure 5 2 is a schematic diagram of a stretching mechanism according to an embodiment of the present invention stretching a special-shaped welding strip and preparing for cutting.

[0029] Figure 6 It is a schematic diagram of the traction mechanism moving to the cutting position after cutting by the cutting mechanism according to an embodiment of the present invention.

[0030] Reference numerals:

[0031] 1. Welding strip stretching device; 2. Welding strip; 3. Circular segment; 4. Non-circular segment;

[0032] 10. Clamping mechanism; 11. Base; 12. Clamping member;

[0033] 20. Stretching mechanism;

[0034] 30. Moving mechanism; 31. Moving rod;

[0035] 40. Pulling mechanism; 50. Identification mechanism; 60. Cutting mechanism; 70. Welding ribbon reel. DETAILED DESCRIPTION

[0036] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Figure 1-Figure 6 A method and device for string welding of photovoltaic cells according to an embodiment of the present invention are described.

[0037] A method for serially welding photovoltaic cells according to an embodiment of the present invention comprises:

[0038] Place a photovoltaic cell on a workbench;

[0039] A special-shaped welding ribbon 2 is pulled out above the photovoltaic cell sheet, and the special-shaped welding ribbon 2 includes a circular segment 3 and a non-circular segment 4 connected to each other;

[0040] Clamping both ends of the non-circular segment 4 and stretching at least one end of the non-circular segment 4;

[0041] Cut the special-shaped welding ribbon 2 and place the circular segment 3 on the surface of a photovoltaic cell;

[0042] Another photovoltaic cell is placed on the non-circular segment 4 .

[0043] For example, before lamination of the photovoltaic cell sheets, the shaped welding tape 2 is arranged on both sides of the thickness direction of the two connected photovoltaic cell sheets, that is, the shaped welding tape 2 includes a plurality of circular segments 3 and non-circular segments 4, and the plurality of circular segments 3 and non-circular segments 4 are alternately arranged in the length direction of the welding tape 2, and each two adjacent circular segments 3 and non-circular segments 4 constitute a complete cycle. Before welding the photovoltaic cell sheets and the shaped welding tape 2, the shaped welding tape 2 includes a plurality of complete cycles of welding tape segments, and after processing, a plurality of complete cycles of stretched welding tape segments are formed. In this embodiment, the stretched welding tape 2 is a complete cycle of welding tape segments. In this embodiment, the shaped welding tape 2 refers to the welding tape whose cross-sectional area changes along the length direction.

[0044] In this embodiment, the special-shaped welding ribbon 2 is suitable for connecting two adjacent photovoltaic cells. When the special-shaped welding ribbon 2 connects two adjacent photovoltaic cells, the circular segment 3 can be located on the front side of one photovoltaic cell, and the non-circular segment 4 can be located on the back side of the other photovoltaic cell. That is, the circular segment 3 and the non-circular segment 4 are respectively located on different sides of two adjacent photovoltaic cells. Since the yield strength of the circular segment 3 is relatively small and it is easy to be stretched, in this embodiment, only the non-circular segment 4 is stretched. When the special-shaped welding ribbon 2 is laminated with the photovoltaic cell, the stretched non-circular segment 4 is opposite to or beyond the edge of the photovoltaic cell when it is cut, which can avoid the risk of node breakage caused by relative squeezing between the circular segment 3 and the edge of the photovoltaic cell.

[0045] In the string welding method of photovoltaic cells, multiple special-shaped welding ribbons 2 are arranged on the cell body. Here, taking the stretching and cutting of one of the special-shaped welding ribbons 2 as an example, a complete cycle of the special-shaped welding ribbon 2 is pulled out from the photovoltaic cell, and the two ends of the non-circular segment 4 included in the special-shaped welding ribbon 2 are clamped. In order to avoid the influence of the stretching process on the circular segment 3, the end of the non-circular segment 4 away from the circular segment 3 is stretched along the length direction of the special-shaped welding ribbon 2 toward the end away from the circular segment 3. After the special-shaped welding ribbon 2 is stretched to a predetermined distance, it is cut off, and the circular segment 3 of the cut special-shaped welding ribbon is placed on one of the two adjacent photovoltaic cells, and the non-circular segment 4 is placed on the other of the two adjacent photovoltaic cells.

[0046] According to the method for string welding of photovoltaic cells according to the embodiment of the present invention, by stretching only the non-circular segment 4 so that the special-shaped welding strip is placed on the photovoltaic cell, the welding strip 2 of the non-circular segment 4 contacts the edge of the photovoltaic cell, thereby avoiding that both the circular segment 3 and the welding strip 2 of the non-circular segment 4 are stretched, avoiding that the circular segment 3 extends out of the edge of the photovoltaic cell during cutting and causes breakage when it stops at the edge of the photovoltaic cell, reducing the possibility of photovoltaic cell splitting, improving the yield of the product, and reducing the production cost and waste of raw materials.

[0047] In this embodiment, the special-shaped solder strip 2 is processed by the solder strip stretching device 1, combined with Figure 1-Figure 5 , wherein the welding strip stretching device 1 comprises: a clamping mechanism 10 and a stretching mechanism 20 arranged at intervals, and the string welding method further comprises: after a complete cycle of the welding strip 2 is pulled out a certain distance, the clamping mechanism 10 and the stretching mechanism 20 work, the clamping mechanism 10 and the stretching mechanism 20 are respectively arranged at both ends of the non-circular segment 4, the clamping mechanism 10 is suitable for clamping one end of the non-circular segment 4 adjacent to the circular segment 3, the clamping mechanism 10 is clamped at one end of the non-circular segment 4 away from the circular segment 3, and the stretching mechanism 20 stretches the non-circular segment 4 toward the end away from the clamping mechanism 10, at which time the welding strip 2 of the non-circular segment 4 is stretched. After the special-shaped welding strip 2 is stretched and extended, the clamping mechanism 10 and the stretching mechanism 20 release the special-shaped welding strip 2.

[0048] Reference Figure 1 and Figure 6The welding strip stretching device 1 also includes: a traction mechanism 40, which can be arranged on a side of the clamping mechanism 10 away from the stretching mechanism 20 along the length direction of the welding strip 2, and the string welding method also includes: before the special-shaped welding strip 2 is stretched, the traction mechanism 40 moves to the free end of the special-shaped welding strip 2, and the traction mechanism 40 is suitable for clamping the free end of the special-shaped welding strip 2 and pulling the special-shaped welding strip 2 from the welding strip reel 70 or from the photovoltaic cell sheet for a predetermined distance and then stops working; when the traction mechanism 40 pulls the special-shaped welding strip 2, the clamping mechanism 10 and the stretching mechanism 20 are in a loosened state of loosening the special-shaped welding strip 2, so as to avoid interference caused by the stretching mechanism 20 and the clamping structure when the traction mechanism 40 pulls the special-shaped welding strip 2, thereby affecting the quality of the special-shaped welding strip 2 and avoiding the special-shaped welding strip 2 from being broken.

[0049] After the special-shaped welding strip 2 is stretched by the stretching mechanism 20 for a predetermined distance, the traction mechanism 40 starts to work, and the special-shaped welding strip 2 continues to move forward by the distance of a circular segment 3 and a non-circular segment 4 under the traction of the traction mechanism 40, and then the traction mechanism 40 stops working. That is, after the special-shaped welding strip 2 is pulled out of the photovoltaic cell sheet by the traction mechanism 40 for a predetermined distance, the clamping mechanism 10 and the stretching mechanism 20 are clamped at both ends of the non-circular segment 4 respectively, wherein the stretching mechanism 20 clamps the special-shaped welding strip 2 at the end of the non-circular segment 4 away from the circular segment 3, and stretches the non-circular segment 4 in the direction away from the clamping mechanism 10, after the stretching is completed, the stretching mechanism 20 and the clamping mechanism 10 send away the welding strip 2, and the traction mechanism 40 works to drive the special-shaped welding strip 2 to continue to move forward for a complete cycle, such as continuing to move by the distance of a circular segment 3 and a non-circular segment 4, and then the traction mechanism 40 stops moving and always keeps clamping the welding strip 2, so that the special-shaped welding strip 2 is kept taut to prevent the special-shaped welding strip 2 from falling off.

[0050] like Figure 1 As shown, the welding strip stretching device 1 also includes: a cutting mechanism 60, and the string welding method further includes: when a complete cycle of the special-shaped welding strip 2 composed of the circular segment 3 and the non-circular segment 4 is stretched, the traction mechanism 40 pulls the special-shaped welding strip 2 forward to move to the end of the non-circular segment 4 within a complete cycle away from the circular segment 3 and opposite to the cutting mechanism 60.

[0051] When the cutting mechanism 60 is opposite to the end of the non-circular segment 4 away from the circular segment 3 , the cutting mechanism 60 cuts the end of the non-circular segment 4 away from the circular segment 3 , so that a complete cycle of the special-shaped welding ribbon 2 is separated from the welding ribbon reel 70 .

[0052] For example, the cutting mechanism 60 is arranged between the clamping mechanism 10 and the welding ribbon reel 70, and cuts the welding ribbon 2 at the connection between the non-circular segment 4 of the previous stretched complete cycle and the circular segment 3 of the next unstretched complete cycle, so that the stretched special-shaped welding ribbon 2 falls from the welding ribbon reel 70 onto the photovoltaic cell.

[0053] The welding strip stretching device 1 also includes: an identification mechanism 50, such as Figure 2 As shown, when the recognition mechanism 50 recognizes that the end of the non-circular segment 4 away from the circular segment 3 is opposite to the cutting mechanism 60, the cutting mechanism 60 is controlled to cut the special-shaped welding strip 2, thereby facilitating the automated processing of the cut special-shaped welding strip 2, and improving the production efficiency and the accuracy of the cutting position. For example, the recognition mechanism 50 is used to identify the node of the special-shaped welding strip 2, and the node is the cutting position that needs to be cut. The recognition mechanism 50 communicates with the cutting mechanism 60. When the recognition mechanism 50 recognizes the node, the signal can be transmitted to the cutting mechanism 60, and the cutting mechanism 60 cuts the special-shaped welding strip 2. The cutting mechanism 60 is arranged adjacent to the traction mechanism 40. When the stretching mechanism 20 stretches the non-circular segment 4, the cutting mechanism 60 is suitable for cutting the end of the non-circular segment 4 away from the circular segment 3.

[0054] like Figure 6 As shown, after the cutting mechanism 60 cuts a complete cycle of the special-shaped welding strip 2, the pulling mechanism 40 returns to the cutting position to re-clamp the end of the special-shaped welding strip 2 and moves forward a predetermined distance to start processing the next complete cycle of the special-shaped welding strip 2. When the pulling mechanism 40 pulls the special-shaped welding strip 2, the stretching mechanism 20 and the clamping mechanism 10 are both in a loose state, so that the special-shaped welding strip 2 passes through the clamping mechanism 10 and the stretching mechanism 20.

[0055] Combination Figure 1-Figure 6 The present application also introduces a photovoltaic cell string welding device, which is suitable for processing a special-shaped welding ribbon 2 in any of the photovoltaic cell string welding methods mentioned above. The string welding device includes: a welding ribbon stretching device 1, which includes a clamping mechanism 10 and a stretching mechanism 20, which are arranged at intervals, and the clamping mechanism 10 is suitable for being arranged at one end of the non-circular segment 4 of the special-shaped welding ribbon 2 adjacent to the circular segment 3 of the special-shaped welding ribbon 2, and the stretching mechanism 20 is suitable for being arranged at one end of the non-circular segment 4 away from the circular segment 3. When the stretching mechanism 20 stretches the special-shaped welding ribbon 2, it can ensure that the non-circular segment 4 of the special-shaped welding ribbon 2 is stretched, and the circular segment 3 is prevented from being stretched, and ensure that the special-shaped welding ribbon 2 is arranged on the photovoltaic cell, and the edge of the photovoltaic cell contacts the non-circular segment 4, which effectively avoids the phenomenon that the photovoltaic cell is cracked due to the deviation of the welding ribbon 2 during lamination caused by the contact between the circular segment 3 and the edge of the photovoltaic cell.

[0056] Furthermore, if Figure 2As shown, the clamping mechanism 10 includes: a base 11 and a clamping member 12, the base 11 is arranged on a workbench; the clamping member 12 is arranged on the base 11, and the clamping member 12 is used to clamp the non-circular segment 4 of the special-shaped welding strip 2 adjacent to the end of the circular segment 3 of the special-shaped welding strip 2; when the special-shaped welding strip 2 needs to be stretched, the clamping member 12 is suitable for clamping the end of the non-circular segment 4 adjacent to the circular segment 3, and the stretching mechanism 20 stretches the non-circular segment 4 at the end of the non-circular segment 4 away from the circular segment 3 toward a direction away from the clamping mechanism 10.

[0057] like Figure 2 As shown, the photovoltaic cell string welding device further includes: a moving mechanism 30, the moving mechanism 30 is arranged between the base 11 and the clamping member 12, the two ends of the moving mechanism 30 are respectively connected to the clamping member 12 and the base 11, and the moving mechanism 30 is used to drive the clamping member 12 to be relatively close to and away from the stretching mechanism 20 to adjust the clamping position of the clamping mechanism 10. That is, the clamping mechanism 10 is connected to the moving mechanism 30, and the moving mechanism 30 is movable along the length direction of the special-shaped welding strip 2, so that the clamping mechanism 10 can be driven to be located at a set position, which is convenient for adjusting the clamping position, so that the welding strip stretching device 1 can be suitable for different stretching scenes and special-shaped welding strips 2 of different specifications. At the same time, the structure of the moving mechanism 30 is simple, which is convenient for improving the existing technology or equipment, and the improvement cost is low. Therefore, the setting of the moving mechanism 30 facilitates the connection between the base 11 and the clamping member 12, and changes the position of the clamping member 12 on the special-shaped welding strip 2, so that the clamping member 12 can clamp different positions on the special-shaped welding strip 2 to meet the set requirements, and has a simple structure, good effects, and can effectively prevent the circular segment 3 from being stretched.

[0058] In some embodiments, the distance that the stretching mechanism 20 moves in the direction away from the clamping mechanism 10 is d, and d satisfies: 5mm≤d≤13mm. Thus, the stretching mechanism 20 stretches the length of the shaped solder strip 2 so that the non-circular section 4 of the shaped solder strip 2 can be ensured to be at the edge of the photovoltaic cell when cutting, thereby preventing the shaped solder strip 2 from offsetting the photovoltaic cell and causing problems such as cold soldering. The specific stretching length needs to be specifically selected according to the photovoltaic cells of different specifications, such as a 210mm photovoltaic cell preferably stretched by 12mm.

[0059] The photovoltaic cell string welding device also includes: a second clamping mechanism (not shown in the figure), which is arranged between the traction mechanism 40 and the clamping mechanism 10 of the welding strip stretching device 1, that is, when the traction mechanism 40 clamps the stretched special-shaped welding strip 2 and moves, when the traction mechanism 40 moves to the cutting position, the second clamping mechanism clamps one end of the non-circular segment 4 adjacent to the circular segment 3, and when the cutting mechanism 60 of the welding strip stretching device 1 cuts the special-shaped welding strip 2, it clamps the stretched special-shaped welding strip 2 to prevent it from falling off.

[0060] The yield strength of the non-circular segment 4 is greater than the yield strength of the circular segment 3. Therefore, when the stretching mechanism 20 stretches the non-circular segment 4, the length of the non-circular segment 4 stretched is less than the length of the circular segment 3 stretched under the same pulling force, while ensuring the structural strength of the special-shaped welding strip 2, the deformation of the non-circular segment 4 and the circular segment 3 under the action of the stretching mechanism 20 is avoided, and the possibility of the circular segment 3 being stretched is reduced. At the same time, the length of the non-circular segment 4 stretched is controlled to avoid excessive stretching that affects the quality of welding between the special-shaped welding strip 2 and the photovoltaic cell.

[0061] The cross-sectional shape of the circular segment 3 is different from the cross-sectional shape of the non-circular segment 4. For example, the cross-sectional shape of the circular segment 3 is a round wire shape, and the cross-sectional shape of the non-circular segment 4 is a flat shape. The flat non-circular segment 4 contacts the edge of the photovoltaic cell after being stretched, which can increase the contact area with the photovoltaic cell, ensure the reliability of the welding of the non-circular segment 4 with the photovoltaic cell on the back of the photovoltaic cell, and dare to ensure the yield of the photovoltaic cell.

[0062] Reference Figure 1 The special-shaped welding strip 2 includes a plurality of circular segments 3 and a plurality of non-circular segments 4, and the plurality of circular segments 3 and the plurality of non-circular segments 4 are staggered and connected along the length direction. The welding strip stretching device 1 stretches at least one of the two ends of the non-circular segment 4 in two adjacent circular segments 3 and non-circular segments 4 according to the design requirements. In this embodiment, the stretching device is used to stretch the end of the non-circular segment 4 away from the circular segment 3.

[0063] Specifically, combined Figure 3-Figure 6 The process of stretching the special-shaped welding strip 2 is as follows:

[0064] The traction mechanism 40 clamps the circular segment 3 of the shaped welding ribbon 2 away from one end of the non-circular segment 4 and stretches it for a period of time, that is, the length of the circular segment 3 and the non-circular segment 4, and during the stretching, the clamping mechanism 10 and the stretching mechanism 20 release the shaped welding ribbon 2 so that the shaped welding ribbon 2 can be pulled out from the welding ribbon reel 70 or the photovoltaic cell sheet. After stretching for a period of time or a predetermined distance, the clamping mechanism 10 and the stretching mechanism 20 clamp the two ends of the non-circular segment 4, and after the clamping structure is stably clamped, the stretching mechanism 20 stretches the non-circular segment 4 in the direction opposite to the moving direction of the shaped welding ribbon 2, so that the non-circular segment 4 is stretched and extended.

[0065] After the stretching is completed, the clamping mechanism 10 and the stretching mechanism 20 are released, and the traction mechanism 40 continues to move with the shaped solder ribbon 2 until the end of the non-circular segment 4 away from the circular segment 3 is identified by the identification mechanism 50, and the cutting mechanism 60 is controlled to cut so that the circular segment 3 and the non-circular segment 4 within a complete stretching cycle are separated from the solder ribbon reel 70 and fall on the photovoltaic cell. After the cutting is completed, the traction mechanism 40 moves to the position where the shaped solder ribbon 2 is cut to re-grasp the free end of the shaped solder ribbon 2, and during the traction process, the clamping mechanism 10 and the stretching mechanism 20 are in a loose state to allow the shaped solder ribbon 2 to pass smoothly, and the above process is repeated to complete the cutting of the shaped solder ribbon 2.

[0066] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred mechanism or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0067] In the description of the present invention, "first feature" and "second feature" may include one or more of the features. In the description of the present invention, "plurality" means two or more. In the description of the present invention, a first feature "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. In the description of the present invention, a first feature "above", "above" and "above" a second feature may include the first feature being directly above and obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example.

[0069] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for string welding of photovoltaic cells, comprising the following method: Place a photovoltaic cell on a workbench; Pull out a special-shaped welding ribbon above the photovoltaic cell sheet, wherein the special-shaped welding ribbon includes a circular segment and a non-circular segment connected to each other; Clamping both ends of the non-circular segment and stretching at least one end of the non-circular segment; Cutting the special-shaped welding strip and placing the circular segment on a surface of the photovoltaic cell sheet; Another photovoltaic cell sheet is placed on the non-circular segment.

2. The photovoltaic cell string welding method according to claim 1, characterized in that: The special-shaped welding strip is processed by a welding strip stretching device, and the welding strip stretching device includes a stretching mechanism and a clamping mechanism. The string welding method includes the following steps: The clamping mechanism and the stretching mechanism work, the clamping mechanism clamps one end of the non-circular segment adjacent to the circular segment, the clamping mechanism clamps one end of the non-circular segment away from the circular segment, and the stretching mechanism stretches the non-circular segment toward the end away from the clamping mechanism; After the special-shaped welding strip is stretched and extended, the clamping mechanism and the stretching mechanism release the special-shaped welding strip.

3. The method for string welding of photovoltaic cells according to claim 1, characterized in that: The welding strip stretching device further includes: a traction mechanism, and the string welding method further includes: Before the special-shaped welding ribbon is stretched, the traction mechanism moves to the free end of the special-shaped welding ribbon, and the traction mechanism is suitable for clamping the free end of the special-shaped welding ribbon and pulling the special-shaped welding ribbon out of the welding ribbon reel by a predetermined distance and then stops working; When the traction mechanism pulls the special-shaped welding strip to move, the clamping mechanism and the stretching mechanism are in a released state for releasing the special-shaped welding strip.

4. The method for serial welding of photovoltaic cells according to claim 3, characterized in that: After the special-shaped welding strip is stretched by the stretching mechanism for a predetermined distance, The traction mechanism starts to work, and the special-shaped welding strip continues to move forward by the distance of one circular segment and one non-circular segment under the traction of the traction mechanism, after which the traction mechanism stops working.

5. The photovoltaic cell string welding method according to claim 4, characterized in that: The welding strip stretching device further includes: a cutting mechanism, and the string welding method further includes: When the special-shaped welding strip of a complete cycle formed by the circular segment and the non-circular segment is stretched, the traction mechanism pulls the special-shaped welding strip forward to the end of the non-circular segment in the complete cycle away from the circular segment and opposite to the cutting mechanism.

6. The method for string welding of photovoltaic cells according to claim 5, characterized in that: When the cutting mechanism is opposite to the end of the non-circular segment away from the circular segment, the cutting mechanism cuts the end of the non-circular segment away from the circular segment, so that a complete cycle of the special-shaped welding ribbon is detached from the welding ribbon reel.

7. The method for string welding of photovoltaic cells according to claim 5, characterized in that: The welding strip stretching device further comprises: an identification mechanism, When the recognition mechanism recognizes that the end of the non-circular segment away from the circular segment is opposite to the cutting mechanism, the cutting mechanism is controlled to cut the special-shaped welding strip.

8. The photovoltaic cell string welding method according to claim 5, characterized in that: After the cutting mechanism cuts a complete cycle of the special-shaped welding strip, the traction mechanism returns to the cutting position to re-clamp the end of the special-shaped welding strip and moves forward a predetermined distance to start processing the next complete cycle of the special-shaped welding strip; wherein, When the traction mechanism is traction of the special-shaped welding strip, the stretching mechanism and the clamping mechanism are both in a loosened state, so that the special-shaped welding strip can pass through the clamping mechanism and the stretching mechanism.

9. A photovoltaic cell string welding device, the photovoltaic cell string welding device is suitable for processing special-shaped welding strips in the photovoltaic cell string welding method according to any one of claims 1 to 8, characterized in that: The string welding device comprises: A welding strip stretching device, the welding strip stretching device comprises a clamping mechanism and a stretching mechanism, the clamping mechanism and the stretching mechanism are arranged at intervals, The clamping mechanism is suitable for being arranged at one end of the non-circular section of the special-shaped welding strip adjacent to the circular section of the special-shaped welding strip, The stretching mechanism is suitable for being arranged at an end of the non-circular segment away from the circular segment.

10. The photovoltaic cell string welding device according to claim 9, characterized in that: The clamping mechanism comprises: A base, wherein the base is arranged on a workbench; A clamping member, the clamping member is disposed on the base, and the clamping member is used to clamp an end of the non-circular segment of the special-shaped welding strip adjacent to the circular segment of the special-shaped welding strip; When the special-shaped welding strip needs to be stretched, the clamping member is suitable for clamping one end of the non-circular segment adjacent to the circular segment, and the stretching mechanism stretches the non-circular segment in a direction away from the clamping mechanism at one end of the non-circular segment away from the circular segment.

11. The photovoltaic cell string welding device according to claim 10, characterized in that: Further including: A moving mechanism, wherein the moving mechanism is disposed between the base and the clamping member, and two ends of the moving mechanism are respectively connected to the clamping member and the base, The moving mechanism is used to drive the clamping member to move relatively close to and away from the stretching mechanism to adjust the clamping position of the clamping mechanism.

12. The photovoltaic cell string welding device according to claim 9, characterized in that: Also includes: The second clamping mechanism is arranged between the traction mechanism of the welding strip stretching device and the clamping mechanism, and clamps the stretched special-shaped welding strip when the cutting mechanism of the welding strip stretching device cuts the special-shaped welding strip to prevent it from falling off.

13. The photovoltaic cell string welding device according to claim 9, characterized in that: The yield strength of the non-circular segment is greater than the yield strength of the circular segment.

14. The photovoltaic cell string welding device according to claim 13, characterized in that: The cross-sectional shape of the circular segment is different from the cross-sectional shape of the non-circular segment.

15. The photovoltaic cell string welding device according to claim 9, characterized in that: The cross-sectional shape of the non-circular segment is flat.

16. The photovoltaic cell string welding device according to any one of claims 9 to 15, characterized in that: The special-shaped welding strip includes a plurality of circular segments and a plurality of non-circular segments, and the plurality of circular segments and the plurality of non-circular segments are staggered and connected along the length direction.

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