Guide insulation sleeve and spot welding machine using same

Abstract

The utility model provides a guide insulation sleeve (12) and a spot welder (1) using the same. The guide insulation sleeve (12) is used for guiding and insulating a welding rod (7) of a spot welding machine (1) and is characterized in that the guide insulation sleeve (12) is sequentially provided with a square base (121), a sleeve (122) and a center correction guide hole (123) from top to bottom, a cavity (12a) is formed in the square base (121) and the sleeve (122), and the cavity (12a) and a mounting seat (7a) of the welding rod (7) can form a clearance sliding matching structure; the center correction guide hole (123) is arranged on the lower surface of the sleeve (122) in an extending mode and is in a hollow pipe shape, a hollow hole (12b) is formed in the center correction guide hole (123), and an electrode (7b) of the welding rod (7) can be inserted into the hollow hole (12b). By adopting the spot welding machine (1) with the guide insulating sleeve (12), the shaking and inclination of the welding rod (7) in the welding of the bottom of the battery can be effectively inhibited, and the external short shunt during welding is avoided.

Description

Technical Field

[0001] This utility model relates to a guide insulating sleeve and a spot welding machine using the same. Background Technology

[0002] Spot welding machines utilize the principle of resistance welding. A welding rod connects the upper and lower electrodes, and welding current flows through the joint of the workpieces. The resistance of the workpieces generates heat, melting the metal at the joint and forming a welded joint. In battery production, spot welding machines are used for bottom welding of cylindrical batteries. Specifically, a welding rod is inserted into the center hole of the wound battery cell, and welding current is conducted between the upper and lower electrodes, thus welding the negative lead of the cell to the bottom of the battery casing. The spot welding machine market is developing towards automation, intelligence, and high precision.

[0003] To improve the welding quality and production stability of the bottom welding of batteries, spot welding machines are usually equipped with guide sleeves to accurately position and guide the displacement of the welding rod, ensuring that the welding rod can be aligned with the target position during the welding process.

[0004] Figure 7 This is a three-dimensional structural diagram of the welding rod (7) used in the spot welding machine, such as... Figure 7 As shown, one end of the welding rod (7) is a cylindrical mounting base (7a), and the other end is a rod-shaped electrode (7b).

[0005] Figure 8 This is a top view of the battery (10) to be welded. The battery (10) has a wound cell (10a) and a battery case (10c) with one end open, as shown. Figure 8 As shown, the wound cell (10a) has a central hole (10b) at its axial center.

[0006] Figure 9 This is a structural diagram of a spot welding machine used in existing technology. For example... Figure 9 As shown, the spot welding machine (1) includes a frame (2), an upper electrode (4), a lower electrode (5), and a guide sleeve (6) connected to the frame (2) via an electrode arm (3). The guide sleeve (6) is located between the upper and lower electrodes (4, 5), and the welding rod (7) is inserted into the guide sleeve (6). In addition, a pressure sensor (8) and a pressure head (9) are located above the upper electrode (4), and the battery (10), which is the object to be welded, is located between the welding rod (7) and the lower electrode (5). The control system (not shown) of the spot welding machine (1) can control the movement of the welding rod (7) through the guide sleeve (6).

[0007] When welding the bottom of the battery, firstly, the lower electrode (5) is lifted to contact the bottom of the battery (10), and the guide sleeve (6) presses down with the welding rod (7), inserting the electrode (7b) of the welding rod (7) into the center hole (10b) of the battery (10). Then, under the control of the motion servo system, the pressure head (9) presses the upper electrode (4) down, so that the upper electrode (4) is connected to the lower electrode (5) through the welding rod (7), thereby performing welding under pressure.

[0008] Figure 10 This is a schematic diagram of the guide sleeve (6) used in existing spot welding technology. For example... Figure 10 As shown in the perspective view of (a), the guide sleeve (6) includes an upper square base (61) and a lower cylindrical sleeve (62), which can be connected to an external control device via an electrode arm. Figure 10 As shown in the cross-sectional view of (b), the guide sleeve (6) has a cylindrical cavity (6a) in the center, and the circumferential surface of the cavity (6a) forms a positioning surface. The cylindrical mounting base (7a) of the welding rod (7) can slide freely up and down in the cavity (6a).

[0009] Figure 11 The diagram shows the usage state of the guide sleeve (6) in the prior art; (a) shows the initial state before the welding rod is inserted into the battery cell; (b) shows the final state after the welding rod is inserted into the battery cell; (c) shows the welding state.

[0010] like Figure 11 As shown, the problem with the prior art is that the mounting base (7a) of the welding rod and the cavity (6a) of the guide sleeve have a clearance sliding fit structure. When the welding rod (7) is in Figure 11 (b) In the final state after inserting the battery cell, the mounting base (7a) of the welding rod (7) extends a considerable distance from the square base (61), reducing the positioning surface of the cavity (6a) of the guide sleeve (6) relative to the mounting base (7a) of the welding rod (7). Therefore, the welding rod (7) is prone to wobbling and tilting. If the welding rod (7) tilts or wobbles, the contact between the welding rod (7) and the bottom of the battery casing and the negative electrode lead (not shown) will be unstable during welding, easily causing solder joint displacement and unstable discharge current. Furthermore, if... Figure 11 As shown in (c), when the inner curvature angle of the positive current collector located above the wound cell (10a) is inconsistent, the positive lead (11) is prone to contact with the electrode (7b) of the welding rod (7), resulting in an external short current shunting and causing a low current alarm. Utility Model Content

[0011] Technical problem to be solved by the utility model

[0012] This utility model is made in response to the above-mentioned problems. Its purpose is to provide a new type of guide insulating sleeve and a spot welding machine using it. By using a spot welding machine with the guide insulating sleeve in the welding of the bottom of the battery, the shaking and tilting of the welding rod can be effectively suppressed, and the external short current shunting during welding can be avoided.

[0013] means for solving technical problems

[0014] The guide insulating sleeve (12) of this utility model is used to guide and insulate the welding rod (7) of the spot welding machine (1). Its features are: from top to bottom, it has a square base (121), a sleeve (122) and a central correction guide hole (123).

[0015] The square base (121) and the sleeve (122) have cavities (12a) inside, which can form a sliding fit with the mounting seat (7a) of the welding rod (7).

[0016] The central correction guide hole (123) is extended on the lower surface of the sleeve (122), and is a hollow tube with an internal cavity (12b). The electrode (7b) of the welding rod (7) can be inserted into the cavity (12b).

[0017] Preferably, the square base (121) has a base (121a) and two sidewalls (121b) extending upward from both sides of the base (121a), with a notch (121c) formed between the two sidewalls (121b).

[0018] Preferably, when the height of the base (121a) of the square base (121) is set to H0, the height of the sleeve (122) is set to H1, and the height of the mounting seat (7a) of the welding rod (7) is set to H3, H3 = H0 + H1 is satisfied.

[0019] Preferably, when the height of the sidewall (121b) of the square base (121) is set to H2, the length of the electrode (7b) of the welding rod (7) is L3, the height of the battery (10) to be welded is L2, and the extension length of the center correction guide hole (123) is L1, L1 < L3 - L2 - H2 is satisfied.

[0020] Preferably, the diameter Φ of the hollow hole (12b) of the central correction guide hole (123) is... 空孔 The outer diameter Φ of the electrode (7b) of the welding rod (7) 电极 The difference is Φ 空孔 -Φ 电极 The range is 0.02~0.10mm.

[0021] Preferably, the lower end of the central correction guide hole (123) is formed with an inwardly inclined guide cone surface (123a) with a guide angle of 4~15°.

[0022] Preferably, the central correction guide hole (123) is formed of an insulating material.

[0023] The spot welding machine (1) of this utility model is used for bottom welding of a battery (10), the battery (10) having a wound cell (10a) and a battery casing (10c) with one end open, characterized in that,

[0024] It has at least an upper electrode (4), a lower electrode (5), a welding rod (7), a pressure head (9), a detection system, a control device, and a guide insulating sleeve (12) as described in any one of the above.

[0025] The detection system detects the position of the center hole (10b) of the wound battery cell (10a) and the position of the welding rod (7);

[0026] The welding rod (7) is inserted into the guide insulating sleeve (12).

[0027] The guide insulating sleeve (12) is connected to the control device.

[0028] The control device, based on the detection results of the detection system, controls the displacement of the welding rod (7) via the guide insulating sleeve (12), thereby inserting the electrode (7b) of the welding rod (7) into the center hole (10b) of the wound battery cell (10a).

[0029] When the electrode (7b) of the welding rod (7) reaches the bottom of the battery case (10c), the pressure head (9) drives the upper electrode (4) to move downward, and the welding rod (7) and the lower electrode (5) are connected to each other. Under pressure, a welding current is applied, thereby welding the negative lead of the wound cell (10a) to the bottom of the battery case (10c).

[0030] Preferably, the detection system includes a camera that detects the position of the center hole of the wound battery cell.

[0031] The control device controls the displacement of the welding rod on the X and Y axes of the horizontal plane through the guide insulating sleeve (12) based on the detection results of the camera.

[0032] Preferably, the detection system includes a photoelectric sensor (13), which is disposed on the side of the guide insulating sleeve (12) to detect the floating state of the welding rod (7).

[0033] The control device controls the Z-axis displacement of the welding rod in the vertical direction through the guide insulating sleeve (12) based on the detection result of the photoelectric sensor (13).

[0034] Preferably, the square base (121) has a base (121a) and two sidewalls (121b) extending upward from both sides of the base (121a), with a notch (121c) between the two sidewalls (121b).

[0035] The photoelectric sensor (13) is positioned between the two sidewalls (121b) and flush with the upper edge of the base (121a), and the light beam emitted by the photoelectric sensor (13) can pass through the notch (121c).

[0036] Preferably, when the photoelectric sensor detects "no abnormal floating of the welding rod", the control device controls the welding rod to continue moving downward along the Z-axis until the electrode of the welding rod is fully inserted into the center hole of the wound cell and reaches the bottom of the battery case; when the photoelectric sensor detects "abnormal floating of the welding rod", the control device stops the downward movement of the welding rod along the Z-axis and terminates the welding operation.

[0037] Utility Model Effect

[0038] The spot welding machine of this utility model adopts a new type of guide insulating sleeve. When welding the bottom of cylindrical batteries, the position of the welding rod mounting seat can be accurately positioned by the square base and sleeve. The center correction guide hole can be used to center the insertion angle of the welding rod electrode and provide insulation protection. This can effectively suppress the shaking and tilting of the welding rod, avoid external short current shunting during welding, and greatly improve the welding quality and production stability of the battery. Attached Figure Description

[0039] Figure 1 The following are structural schematic diagrams illustrating an example of the guide insulating sleeve of this utility model: (a) perspective view; (b) sectional view.

[0040] Figure 2 The diagram shows the usage state of the guide insulating sleeve of this utility model; (a) the initial state before the welding rod is inserted into the battery cell; (b) the final state after the welding rod is inserted into the battery cell; (c) the welding state.

[0041] Figure 3 This is a three-dimensional structural diagram of the spot welding machine of this utility model.

[0042] Figure 4 This is a schematic diagram showing the initial state of the spot welding machine of this utility model.

[0043] Figure 5 This is a schematic diagram showing the welding state of the spot welding machine of this utility model.

[0044] Figure 6 This diagram illustrates the working process of the spot welding machine of this utility model.

[0045] Figure 7 A three-dimensional structural diagram of the welding rod.

[0046] Figure 8 This is a top view of a cylindrical battery.

[0047] Figure 9 A schematic diagram showing the structure of a spot welding machine in the prior art.

[0048] Figure 10 The structural schematic diagram of the guide sleeve in the prior art is shown in (a) perspective view and (b) sectional view.

[0049] Figure 11 The diagram shows the usage state of the guide sleeve in the prior art; (a) the initial state before the welding rod is inserted into the battery cell; (b) the final state after the welding rod is inserted into the battery cell; and (c) the welding state.

[0050] Figure 12 The diagram illustrates the improved current distribution when using the spot welding machine of this invention for welding the bottom of a battery. (a) Current distribution before improvement; (b) Current distribution after improvement. Detailed Implementation

[0051] Spot welding machines equipped with guide sleeves are widely used in the bottom welding of cylindrical batteries. The guide sleeve is typically mounted on the electrode arm, and its internal cavity has a sliding fit with the welding rod mounting base. Through precise aperture design, it ensures that the welding rod maintains a straight line during its vertical (Z-axis) movement, preventing positional misalignment. Furthermore, during welding, the guide sleeve can fine-tune the horizontal position of the welding rod (X-axis and Y-axis) to ensure alignment between the electrode head and the welding point. Therefore, the guide sleeve used in spot welding machines is a key component for improving welding quality and battery production efficiency.

[0052] The guide insulating sleeve of this utility model is a guide sleeve that can more accurately guide and insulate the welding rod in a spot welding machine. The specific embodiments of the guide insulating sleeve of this utility model and the spot welding machine using it will be described below with reference to the accompanying drawings.

[0053] Figure 1 The following are structural schematic diagrams illustrating an example of the guide insulating sleeve of this utility model: (a) perspective view; (b) sectional view.

[0054] like Figure 1 As shown, the guide insulating sleeve (12) has a square base (121), a sleeve (122) and a central correction guide hole (123) from top to bottom. The square base (121) and the sleeve (122) have cavities (12a) inside, which can form a gap sliding fit with the mounting seat (7a) of the welding rod (7). The central correction guide hole (123) is extended on the lower surface of the sleeve (122), is hollow tubular, and has a hole (12b) inside. The electrode (7b) of the welding rod (7) can be inserted into the hole (12b).

[0055] The circumferential surface of the cavity (12a) forms the positioning guide surface of the mounting base (7a) for the welding rod. The two are in a clearance fit, which ensures that the welding rod can slide freely up and down in the cavity while being accurately positioned and guided. As an example, when the outer diameter Φ of the mounting base is... 安装座 When the diameter is 18mm, the cavity diameter Φ can be set. 空腔 With respect to the outer diameter Φ of the mounting base 安装座 The difference should be in the range of 0.02~0.08mm, preferably in the range of 0.03mm~0.05mm, in order to achieve a good clearance fit.

[0056] In this invention, the outer surface of the sleeve (122) can be cylindrical or other shapes, and its interior is part of a cavity (12a). A hollow tubular center correction guide hole (123) is provided on the lower surface of the sleeve (122) extending downwards, into which the electrode (7b) can be inserted. Therefore, the positioning and guiding effect on the welding rod can be further improved. A clearance fit is also preferred between the center correction guide hole and the electrode of the welding rod. As an example, when the outer diameter Φ of the welding rod electrode... 电极 When the diameter is 3.0mm, the diameter Φ of the hole (12b) of the center correction guide hole (123) can be set. 空孔 The outer diameter Φ of electrode (7b) 电极 The difference, i.e., Φ 空孔 -Φ 电极 The range is 0.02~0.10mm, preferably 0.05~0.1mm, and most preferably 0.05mm.

[0057] Since the guide insulating sleeve (12) of this utility model has a square base (121) and a sleeve (122) and a central correction guide hole (123) located below, it can ensure that the electrode of the welding rod is always in a vertical state when it is inserted, so that the relative position of the welding rod and the negative electrode lead at the bottom of the battery is more accurate and the contact is reliable, thus achieving a stable welding effect.

[0058] Figure 2This is a schematic diagram illustrating the usage states of the guide insulating sleeve of this utility model; (a) shows the initial state before the welding rod is inserted into the battery cell; (b) shows the final state after the welding rod is inserted into the battery cell; (c) shows the welding state. For ease of display, Figure 2 The illustration of battery (10) is omitted in (a) and (b).

[0059] like Figure 2 As shown in (a), in the initial state before the welding rod is inserted into the battery cell, the mounting base (7a) of the welding rod (7) is completely contained in the cavity (12a) of the guide insulating sleeve (12), so a stable and reliable positioning guide can be obtained, and the electrode (7b) of the welding rod (7) passes through the center correction guide hole (123) located below the guide insulating sleeve (12), and its insertion angle can be accurately centered.

[0060] Furthermore, in the guide insulating sleeve (12) of this utility model, in order to ensure that the welding rod (7) also has a sufficient positioning surface in the welding state, the two sides of the base bottom (121a) of the square base (121) are raised to form upwardly extending sidewalls (121b). Therefore, as Figure 2 As shown in (b), in the final state after the welding rod is inserted into the battery cell, the surface of the mounting base (7a) remains flush with the upper surface of the square base (121). At this time, the positioning area of ​​the cavity (6a) of the guide insulating sleeve (12) relative to the mounting base (7a) of the welding rod (7) remains unchanged. Therefore, the welding rod (7) can still obtain stable and reliable positioning guidance.

[0061] Since the mounting base (7a) of the welding rod (7) is completely contained in the cavity (6a) inside the guide insulating sleeve (12) whether it is the initial state before inserting the battery cell or the final state after inserting the battery cell, it can be ensured that the positioning will not fail due to local dimensional changes of the welding rod (7) or the guide insulating sleeve (12).

[0062] The centrally located guide hole (123) of the guide insulating sleeve (12) is preferably formed of insulating material. At this time, as... Figure 2 As shown in (c), in the welding state, the center correction guide hole (123) can prevent the positive lead (11) of the wound cell (10a) from contacting the electrode (7b) of the welding rod (7), thus providing good insulation.

[0063] Furthermore, to prevent excessive curvature of the positive current collector in the battery cell, and to prevent the electrodes of the welding rod from contacting the battery cell leads (e.g., the positive lead), such as... Figure 1As shown in (b), the lower end of the preferred center correction guide hole (123) is formed with an inwardly inclined guide cone surface (123a). In order to achieve a good guiding effect, its guide angle (the angle formed with the vertical line) can be 4~15°, preferably 5~10°, and most preferably 5°.

[0064] By designing a guide cone surface (123a) at the lower end of the central correction guide hole (123), when the inner curvature angle of the positive current collector above the wound cell (10a) fluctuates and the positive lead (11) tilts inward, the external short current shunting phenomenon caused by accidental contact between the positive lead (11) and the metal electrode (7b) of the welding rod (7) can be effectively suppressed, or the cell lead can be damaged.

[0065] Figure 3 This is a three-dimensional structural schematic diagram of the spot welding machine of this utility model. The spot welding machine of this utility model is preferably used for bottom welding of a cylindrical battery, which has a wound cell (10a) and a battery casing (10c) with one open end. The spot welding machine of this utility model is characterized by having the aforementioned guide insulating sleeve.

[0066] like Figure 3 As shown, the spot welding machine (1) of this utility model includes at least an upper electrode (4), a lower electrode (5), a welding rod (7), a pressure head (9), a detection system and control device (not shown), and the aforementioned guide insulating sleeve (12). At this time, the welding rod (7) is inserted into the guide insulating sleeve (12), and the square base (121) or sleeve (122) of the guide insulating sleeve (12) is connected to the control device through the electrode arm.

[0067] The detection system is used to detect the position of the center hole (10b) of the wound cell (10a) of the battery (10) which is to be welded, and the position of the welding rod (7); the control device controls the displacement of the welding rod (7) through the guide insulating sleeve (12) according to the detection result of the detection system, thereby inserting the electrode (7b) of the welding rod (7) into the center hole (10b) of the wound cell (10a).

[0068] When the electrode (7b) of the welding rod (7) reaches the bottom of the battery case (10c) of the battery (10), the pressure head (9) drives the upper electrode (4) to move downward, and conducts through the welding rod (7) and the lower electrode (5), and applies welding current under pressure, thereby welding the negative lead of the wound cell (10a) to the bottom of the battery case (10c).

[0069] Preferably, the detection system of this utility model includes a camera (not shown), which detects the position of the center hole of the wound battery cell. Then, the control device controls the displacement of the welding rod on the X-axis and Y-axis of the horizontal plane through the guide insulating sleeve (12) based on the detection result of the camera.

[0070] In other words, before welding, the camera detects and positions the center hole (10b) of the battery (10) to be welded and the electrode (7b) of the welding rod (7). Based on the detection results of the camera, the control device (not shown) adjusts the position of the square base (121) of the guide insulating sleeve (12) in the horizontal direction by adjusting the position of the electrode arm, thereby controlling the displacement of the welding rod (7) in the X and Y axes. More specifically, the control device compares the actual position of the electrode (7b) with the initial position (i.e., directly above the center hole (10b)) and calculates the position deviation. Based on the magnitude and direction of the deviation, the control device fine-tunes the position of the electrode, so that the electrode (7b) quickly and stably reaches the initial position. After the electrode (7b) reaches the initial position, the control device moves the guide insulating sleeve (12) vertically downward, thereby controlling the displacement of the welding rod (7) in the Z axis direction, and finally reaching the target position in the welding state.

[0071] Figure 4 This is a schematic diagram showing the initial state of the spot welding machine of this utility model before startup. Figure 5 This is a schematic diagram showing the welding state of the spot welding machine of this utility model.

[0072] As described above, the spot welding machine (1) of this utility model needs to initialize the position of the welding rod (7) before starting, to ensure that the end of the electrode (7b) of the welding rod (7) is located in the preset initial position, that is, directly above the center hole (10b) of the wound cell (10a) of the battery (10).

[0073] If foreign objects or protrusions remain inside the center hole (10b) during the process of inserting the electrode (7b) into the center hole (10b), or if the insertion angle of the electrode (7b) is not perpendicular enough, the electrode (7b) will be obstructed and cannot be inserted smoothly, causing the mounting base (7a) of the welding rod (7) to float upward relative to the guide insulating sleeve (12). This phenomenon is called "abnormal floating".

[0074] In the bottom welding of batteries, monitoring the abnormal floating of the welding rod is an important step to ensure welding quality and stability. In previous spot welding machines, the abnormal floating of the welding rod (7) mainly relied on the abnormal response value of the pressure sensor to monitor it. However, the problem is that the pressure sensor often cannot detect the abnormality and provide feedback in time, which causes the electrode (7b) to damage the inner circumferential surface of the wound cell (10a) during the insertion of the electrode (7b) into the center hole (10b).

[0075] In this invention, a photoelectric sensor (13) is preferably included in the detection system. The photoelectric sensor (13) is disposed on the side of the guide insulating sleeve (12) to detect abnormal floating state of the welding rod (7). Furthermore, the control device controls the displacement of the welding rod in the vertical Z-axis direction through the guide insulating sleeve (12) based on the detection result of the photoelectric sensor (13).

[0076] By installing a photoelectric sensor (13), the actual position of the welding rod (7) can be monitored in real time, and the data can be transmitted to the control device to determine in a timely manner whether the welding rod has experienced abnormal floating. When the monitoring result of the photoelectric sensor is "no abnormal floating of the welding rod detected" (OK), the control device controls the welding rod to continue moving downward along the Z-axis until the electrode of the welding rod is fully inserted into the center hole of the wound cell and reaches the bottom (lower limit) of the battery case; when the monitoring result of the photoelectric sensor is "abnormal floating of the welding rod detected" (NG), the control device stops the downward movement of the welding rod along the Z-axis and stops the welding operation. In this way, it can effectively avoid damage to the separator or active material layer of the wound cell (10a) caused by improper insertion of the welding rod.

[0077] In order to detect abnormal floating of the welding rod (7), the photoelectric sensor (13) needs to be set at a position flush with the upper edge of the mounting base (7a) of the welding rod (7) in the initial state. In this way, if the mounting base (7a) floats abnormally, the light beam emitted from the photoelectric sensor (13) will be blocked immediately, thereby generating a detection signal.

[0078] In the guide insulating sleeve (12) of this invention, in order to ensure sufficient positioning surface for the welding rod (7) even in the welding state, the two sides of the base (121a) of the square base (121) are raised to form upwardly extending sidewalls (121b). Depending on the specific situation, the height H2 of the sidewall can be 10~30mm, preferably 15~25mm, and more preferably 16~23mm. As a specific example, the height H2 of the sidewall is, for example, 22mm.

[0079] In this case, in order to detect abnormal floating of the welding rod (7) during the insertion process in a timely manner, the photoelectric sensor (13) needs to be placed between the two side walls (121b) and flush with the upper edge of the base (121a). In this way, the notch (121c) formed between the two side walls (121b) can serve as a photoelectric detection slot, allowing the light beam emitted from the photoelectric sensor (13) to pass through the notch (121c). As a specific example, the photoelectric sensor (13) is placed at the notch (121c), about 30mm from the bottom of the square base (121).

[0080] This invention, by setting a photoelectric sensor (13) on the side of the guide insulating sleeve (12), can detect the abnormal floating of the welding rod (7) in a timely manner, and avoid damage to the battery separator or active material layer caused by improper insertion of the electrode (7b).

[0081] Furthermore, when the guide insulating sleeve (12) drives the welding rod (7) to a preset lower limit position, that is, when the electrode (7b) just touches the bottom of the battery case and stops descending, the detection of the photoelectric sensor (13) can be temporarily stopped. After that, the guide insulating sleeve (12) together with the photoelectric sensor (13) continues to descend a certain distance until the mounting base (7a) of the welding rod (7) is exposed from the upper edge of the square base (121) of the guide insulating sleeve (12).

[0082] Then, as Figure 5 As shown, the spot welding machine (1) of this utility model enters the welding state. At this time, the pressure head (9) presses the upper electrode (4) down under the control of the motion servo system, so that the upper electrode (4) is connected to the lower electrode (5) through the welding rod (7), thereby performing welding under pressure.

[0083] In the welding state, since the guide insulating sleeve (12) of this utility model has a central correction guide hole (123) and a guide cone surface (123a) designed at the lower end, even if the inner curvature angle of the positive current collector of the wound cell (10a) fluctuates and the positive lead (11) tilts inward, it can effectively suppress the external short current phenomenon caused by accidental contact between the positive lead (11) and the metal electrode (7b) of the welding rod (7) or damage to the cell lead.

[0084] As long as the above welding process can be carried out smoothly, there are no special provisions for the size of the guide insulating sleeve (12) used in the spot welding machine (1) of this utility model, but it is preferred to meet certain design requirements.

[0085] Specifically, such as Figure 1 (b) and Figure 7As shown, when the height of the base (121a) of the square base (121) is set to H0, the height of the sleeve (122) to H1, the height of the side wall (121b) of the square base (121) to H2, and the height of the mounting base (7a) of the welding rod (7) to H3, it is preferable to satisfy H3≥H0+H1, and more preferably to satisfy H0+H1+H2≥H3≥H0+H1. In this way, the upper surface of the mounting base (7a) can be ensured to be exposed through the notch (121c) of the square base (121), ensuring that the photoelectric sensor (13) can detect the abnormal floating of the welding rod (7) in a timely manner. From the perspective of further improving the detection sensitivity and reducing the interference of the installation position deviation of the photoelectric sensor (13) on the measurement results, it is particularly preferable to satisfy H3=H0+H1.

[0086] In addition, such as Figure 1 (b) Figure 2 (c) and Figure 7 As shown, when the height of the sidewall (121b) of the square base (121) is H2, the length of the electrode (7b) of the welding rod (7) is L3, the height of the battery (10) is L2, and the extension length of the center correction guide hole (123) of the guide insulating sleeve (12) is L1, it is preferable to satisfy L1 < L3 - L2 - H2. In this way, it can be ensured that there is a certain gap between the bottom end of the center correction guide hole (123) and the battery (10), preferably more than 2mm, that is, L3 - L2 - H2 - L1 ≥ 2mm, so as to ensure that the center correction guide hole (123) does not directly contact the wound cell (10a) and damage the positive current collector.

[0087] The extension length L1 of the center correction guide hole (123) mainly depends on the length of the exposed portion of the electrode (7b) after the welding rod (7) is fully inserted into the battery cell (10a). In order to give full play to the center correction and guiding role of the center correction guide hole (123) on the electrode (7b), the extension length L1 of the center correction guide hole (123) is preferably 10mm to 60mm, more preferably 12mm to 58mm, and even more preferably 14mm to 30mm. As a specific example, the extension length L1 of the center correction guide hole (123) can be 10 to 20mm.

[0088] To ensure safety, the central alignment guide hole (123) is preferably formed of an insulating material, such as urea resin. The square base (121), sleeve (122), and central alignment guide hole (123) in the guide insulating sleeve (12) can be formed integrally or separately. The guide insulating sleeve (12) is preferably formed integrally of an insulating material.

[0089] The welding rod (7) used in the spot welding machine of this utility model is as follows: Figure 7As shown, one end is a cylindrical mounting base (7a), and the other end is a rod-shaped electrode (7b). The welding rod can be a one-piece structure or a separate structure. In the case of a separate structure, the rod-shaped electrode (7b) is usually made of chromium-copper alloy, while the cylindrical mounting base (7a) is made of copper. The rod-shaped electrode (7b) can be replaced at any time according to the usage conditions by means of a locking block provided on the mounting base.

[0090] In this utility model, the battery (10) that is to be welded is as follows: Figure 8 As shown, a battery case (10c) with one open end and a wound-type battery cell (10a) housed therein are arranged in a spiral manner. The wound-type battery cell (10a) has a central hole (10b) at its axial center. The wound-type battery cell (10a) is formed by winding a positive current collector and a negative current collector coated with active material layers, with a separator sandwiched between them. The positive current collector has a positive lead (11) on the upper open side, and the negative current collector has a negative lead (not shown) on the bottom side.

[0091] Figure 6 This is a schematic diagram of the working process of the spot welding machine of this utility model.

[0092] First, a camera is used to confirm the position of the center hole of the battery cell before welding. Based on the camera's position data, the spot welding machine moves its X and Y axes to the center hole position (the initial position of the welding rod). Then, the welding rod moves along the Z axis to insert. When the welding rod encounters resistance and floats up (NG) during insertion into the battery cell hole, the spot welding machine terminates the welding operation and triggers a stop alarm. When normal insertion (OK) is detected, the upper and lower electrodes of the spot welding machine contact and apply pressure. When the pressure sensor reaches the set value, the spot welding machine discharges. After discharge, the upper and lower electrodes return to their original positions, the welding rod is pulled out, and the transfer axis returns to its origin, awaiting the next operation.

[0093] The spot welding machine of this invention has achieved good results in actual battery bottom welding by adopting a new type of guide insulating sleeve (12).

[0094] When using the existing guide sleeve, the welding rod mounting base is raised and exposed during welding, reducing the positioning surface and causing the welding rod to tilt and wobble by approximately 0.55 mm. Therefore, in actual battery bottom welding, about 10-20 out of 1000 batteries will experience a low current alarm.

[0095] In contrast, the guide insulating sleeve of this utility model, through the design of increasing the height of the guide insulating sleeve and the downward extension design of the central correction guide hole, can ensure reliable positioning of the welding rod and ensure the stability of the center position of the electrode.

[0096] To verify the above effects, actual tests were conducted on the bottom welding of two groups of 32 batteries each using a constant voltage mode. The experimental data are shown in Table 1 and Table 2. Figure 12 As shown. "Before improvement" refers to the situation where the bottom of the battery is welded using a spot welding machine equipped with an existing guide sleeve, while "after improvement" refers to the situation where the bottom of the battery is welded using a spot welding machine equipped with the guide insulating sleeve of this utility model. Furthermore, Figure 12 This is a schematic diagram showing the improved current distribution when using the spot welding machine of this invention to weld the bottom of a battery. (a) Current distribution before improvement; (b) Current distribution after improvement.

[0097] Table 1

[0098]

[0099] From Table 1 and Figure 12 It can be seen that by adopting the guide insulating sleeve of this utility model, compared with the existing guide sleeve, the standard deviation of the welding current of the spot welding machine is reduced by more than 3 times, indicating that the fluctuation of the welding current tends to be stable, effectively solving the problem of low current failure alarm during welding, and greatly improving engineering capabilities.

[0100] The specific embodiments of the guide insulating sleeve and spot welding machine of this utility model have been described above with reference to the accompanying drawings. However, this utility model is not limited to the specific embodiments described above. Various modifications or combinations and changes of elements can be made without departing from the spirit of this utility model. These modifications or combinations and changes of elements are also included within the protection scope of this utility model.

[0101] Symbol Explanation

[0102] 1. Spot welding machine

[0103] 2 racks

[0104] 3 electrode arms

[0105] 4. Upper electrode

[0106] 5 Lower electrode

[0107] 6 guide sleeves

[0108] 61 Square base

[0109] 62 sleeve

[0110] 6a Cavity

[0111] 7 Welding rods

[0112] 7a Mounting Base

[0113] 7b electrode

[0114] 8. Pressure sensor

[0115] 9. Pressure Head

[0116] 10 batteries

[0117] 10a wound cell

[0118] 10b center hole

[0119] 10c battery case

[0120] 11 Positive lead

[0121] 12 Guide insulating sleeve

[0122] 121 Square base

[0123] 121a base

[0124] 121b sidewall

[0125] 121c gap

[0126] 122 Sleeve

[0127] 123 Center Correction Guide Hole

[0128] 123a Guide cone surface

[0129] 12a Cavity

[0130] 12b Hole

[0131] 13. Photoelectric Sensors

Claims

1. A guide insulating sleeve (12) for guiding and insulating the welding rod (7) of a spot welding machine (1), characterized in that: From top to bottom, it has a square base (121), a sleeve (122) and a central correction guide hole (123). The square base (121) and the sleeve (122) have cavities (12a) inside, which can form a sliding fit with the mounting seat (7a) of the welding rod (7). The central correction guide hole (123) is extended on the lower surface of the sleeve (122), and is a hollow tube with an internal cavity (12b). The electrode (7b) of the welding rod (7) can be inserted into the cavity (12b).

2. The guide insulating sleeve according to claim 1, characterized in that, The square base (121) has a base (121a) and two sidewalls (121b) extending upward from both sides of the base (121a), with a notch (121c) formed between the two sidewalls (121b).

3. The guide insulating sleeve according to claim 2, characterized in that, When the height of the base (121a) of the square base (121) is set to H0, the height of the sleeve (122) is set to H1, and the height of the mounting seat (7a) of the welding rod (7) is set to H3, H3 = H0 + H1 is satisfied.

4. The guide insulating sleeve according to claim 3, characterized in that, When the height of the sidewall (121b) of the square base (121) is set to H2, the length of the electrode (7b) of the welding rod (7) is L3, the height of the battery (10) to be welded is L2, and the extension length of the center correction guide hole (123) is L1, L1 < L3 - L2 - H2 is satisfied.

5. The guide insulating sleeve according to claim 1 or 2, characterized in that, The diameter Φ of the hollow (12b) of the central correction guide hole (123) 空孔 The outer diameter Φ of the electrode (7b) of the welding rod (7) 电极 The difference is Φ 空孔 -Φ 电极 The range is 0.02~0.10mm.

6. The guide insulating sleeve according to claim 1 or 2, characterized in that, The lower end of the central correction guide hole (123) is formed with an inwardly inclined guide cone surface (123a) with a guide angle of 4~15°.

7. The guide insulating sleeve according to claim 1 or 2, characterized in that, The central correction guide hole (123) is formed of insulating material.

8. A spot welding machine (1) for bottom welding of a battery (10), the battery (10) comprising a wound cell (10a) and a battery casing (10c) open at one end, characterized in that, It includes at least an upper electrode (4), a lower electrode (5), a welding rod (7), a pressure head (9), a detection system, a control device, and a guide insulating sleeve (12) as described in any one of claims 1 to 7. The detection system detects the position of the center hole (10b) of the wound battery cell (10a) and the position of the welding rod (7); The welding rod (7) is inserted into the guide insulating sleeve (12). The guide insulating sleeve (12) is connected to the control device. The control device, based on the detection results of the detection system, controls the displacement of the welding rod (7) via the guide insulating sleeve (12), thereby inserting the electrode (7b) of the welding rod (7) into the center hole (10b) of the wound battery cell (10a). When the electrode (7b) of the welding rod (7) reaches the bottom of the battery case (10c), the pressure head (9) drives the upper electrode (4) to move downward, and the welding rod (7) and the lower electrode (5) are connected to each other. Under pressure, a welding current is applied, thereby welding the negative lead of the wound cell (10a) to the bottom of the battery case (10c).

9. The spot welding machine according to claim 8, characterized in that, The detection system includes a camera that detects the position of the center hole in the wound battery cell. The control device controls the displacement of the welding rod on the X and Y axes of the horizontal plane through the guide insulating sleeve (12) based on the detection results of the camera.

10. The spot welding machine according to claim 8 or 9, characterized in that, The detection system includes a photoelectric sensor (13), which is disposed on the side of the guide insulating sleeve (12) to detect the floating state of the welding rod (7). The control device controls the Z-axis displacement of the welding rod in the vertical direction through the guide insulating sleeve (12) based on the detection result of the photoelectric sensor (13).

11. The spot welding machine according to claim 10, characterized in that, The square base (121) has a base (121a) and two sidewalls (121b) extending upward from both sides of the base (121a), with a notch (121c) between the two sidewalls (121b). The photoelectric sensor (13) is positioned between the two sidewalls (121b) and flush with the upper edge of the base (121a), and the light beam emitted by the photoelectric sensor (13) can pass through the notch (121c).

12. The spot welding machine according to claim 10, wherein, When the photoelectric sensor detects "no abnormal floating of the welding rod", the control device controls the welding rod to continue moving downward along the Z-axis until the electrode of the welding rod is fully inserted into the center hole of the wound cell and reaches the bottom of the battery case; when the photoelectric sensor detects "abnormal floating of the welding rod", the control device stops the downward movement of the welding rod along the Z-axis and terminates the welding operation.

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