High-cost-performance detection projection welding electrode with nut

Abstract

The utility model relates to the field of resistance projection welding, in particular to a high-cost-performance detection projection welding electrode with nuts, which comprises an upper electrode and a lower electrode, the upper electrode comprises an upper electrode bottom plate, an upper electrode seat, an upper electrode cooling pipe, an upper electrode stem, an upper electrode tip and an upper electrode insulating ring, and the upper electrode insulating ring is sleeved outside the bottom end of the upper electrode tip. The extension length of the upper electrode insulation ring is larger than that of the upper electrode tip, and the upper electrode insulation ring is used for being in contact with the lower electrode to form an open circuit when the nut is staggered. Compared with a traditional high-precision displacement sensor scheme, the structure utilizes insulation ring open circuit detection and spring linkage induction, the hardware cost is greatly reduced, and the problem that medium and small enterprises are difficult to adopt high-precision detection due to cost limitation is solved.

Description

Technical Field

[0001] This utility model relates to the field of resistance projection welding technology, and in particular to a high-performance projection welding electrode with nut for detection. Background Technology

[0002] Nut projection welding is a resistance welding method that involves pre-machining welding protrusions or rings on the nut, bringing them into contact with the surface of the sheet metal workpiece, heating them with electricity, and then pressing them down to form a weld. Accurate placement of the nut is a crucial step in the production process during nut projection welding. Failure to place it correctly, such as omitting it, placing it upside down, or incorrectly positioning it, will result in substandard welding quality, product scrap, and damage to the welding electrodes.

[0003] Therefore, a mechanism is needed to determine the placement of the nut to prevent product scrap, defective products from being released, and damage to the welding electrode. Currently, the most common solution on the market is to use a high-precision displacement sensor to detect the displacement of the locating pin to determine the nut's placement. However, this solution is very expensive, making it unaffordable for many manufacturers. Therefore, this invention proposes a cost-effective projection welding electrode with nut detection to solve this problem. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-performance, cost-effective projection welding electrode with a nut for detection.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A cost-effective projection weld detection electrode with nut includes an upper electrode and a lower electrode. The upper electrode includes an upper electrode base plate, an upper electrode seat, an upper electrode cooling pipe, an upper electrode rod, an upper electrode head, and an upper electrode insulating ring. The upper electrode insulating ring is sleeved outside the bottom end of the upper electrode head, and the extension length of the upper electrode insulating ring is greater than that of the upper electrode head. The upper electrode insulating ring is used to contact the lower electrode to form an open circuit when the nut is misaligned.

[0007] The lower electrode includes a pneumatic positioning pin, a lower electrode cap, a lower electrode sleeve, a water inlet sealing ring, an electrode seat steel sleeve, a water inlet sealing ring, a sensor sensing spring, a positioning pin support spring, a lower electrode seat, an inductive sensor, and a lower electrode base plate. The pneumatic positioning pin is connected to the lower electrode seat through the positioning pin support spring and is linked with the sensor sensing spring. The inductive sensor is installed on the lower electrode base plate and is used to detect the displacement change of the pneumatic positioning pin to determine the placement status of the nut.

[0008] The upper electrode and the lower electrode are each provided with an independent cooling circuit. The cooling circuit of the upper electrode is set on the upper electrode holder, and the cooling circuit of the lower electrode is set on the lower electrode holder.

[0009] In addition, a preferred structure is that the upper electrode holder is located at the bottom of the upper electrode base plate, the interior of the upper electrode holder is hollow, the upper electrode cooling pipe is connected inside the upper electrode holder, and the upper electrode rod is sleeved on the outside of the upper electrode cooling pipe.

[0010] In addition, a preferred structure is that an upper electrode water inlet is provided on one side wall of the upper electrode holder, and an upper electrode water outlet is provided below the upper electrode water inlet. The upper electrode water inlet and the upper electrode water outlet are the cooling circuits of the upper electrode, and both are connected to the inner cavity of the upper electrode holder.

[0011] In addition, a preferred structure is that the upper electrode rod is a slender tube with a through-hole, and an upper electrode sleeve is provided at the bottom of the upper electrode rod. One end of the upper electrode sleeve is connected to the upper electrode rod through a taper, and the other end is connected to the upper electrode head through a taper. The upper electrode head directly contacts the upper end face of the projection weld nut during welding.

[0012] Furthermore, in a preferred configuration, a wiring groove is provided on the lower electrode base plate for mounting an inductive sensor. A lower electrode seat is mounted on the upper surface of the lower electrode base plate, and a cavity is provided inside the lower electrode seat. The top of the lower electrode seat is connected to a lower electrode sleeve via a thread. A lower electrode cap is mounted on the upper surface of the lower electrode sleeve, and a through hole is vertically provided in the center of the lower electrode cap. A pneumatic positioning pin extends upward from the central through hole of the lower electrode cap, and the bottom of the pneumatic positioning pin is located inside the cavity of the lower electrode seat.

[0013] In addition, a preferred structure is that an electrode seat steel sleeve is fitted outside the lower electrode seat, a water channel sealing ring is provided on the top of the electrode seat steel sleeve and below the lower electrode sleeve, and a water channel lower sealing ring is provided at the bottom of the electrode seat steel sleeve.

[0014] Furthermore, in a preferred configuration, the lower electrode base has symmetrically arranged lower electrode water inlets and lower electrode water outlets on both sides, which communicate with the internal cavity of the lower electrode base. The lower electrode water inlet and lower electrode water outlet are adjacent to each other and have lower electrode air inlets that communicate with the internal cavity of the lower electrode base. The lower electrode water inlet, lower electrode water outlet, waterway sealing ring, electrode base steel sleeve, and waterway lower sealing ring constitute the cooling circuit of the lower electrode.

[0015] In addition, a preferred structure is that the bottom of the pneumatic positioning pin is provided with a positioning pin support spring, the bottom of the pneumatic positioning pin abuts against the top of the positioning pin support spring, the bottom of the positioning pin support spring abuts against the bottom wall of the cavity inside the lower electrode seat, and the sensor sensing spring is installed at the bottom of the pneumatic positioning pin and moves up and down with the pneumatic positioning pin. Its length is designed according to the sensing distance of the inductive sensor.

[0016] The beneficial effects of this utility model are as follows:

[0017] 1. This utility model achieves accurate detection of the nut's placement state through the collaborative design of the upper electrode insulating ring and the inductive sensor. Compared with traditional high-precision displacement sensor solutions, this structure utilizes insulating ring open-circuit detection and spring linkage sensing, significantly reducing hardware costs and solving the pain point that small and medium-sized enterprises cannot adopt high-precision detection due to cost constraints.

[0018] 2. The pneumatic positioning pin works in conjunction with the sensor spring to monitor the nut position deviation in real time. The sensor provides feedback signals to ensure that abnormal conditions such as reversed or offset nuts are promptly alarmed. This dual protection significantly reduces the product scrap rate.

[0019] 3. The upper and lower electrodes adopt an independent cooling circuit design (upper electrode water inlet, upper electrode water outlet, lower electrode water inlet, and lower electrode water outlet), which provides directional cooling for the electrode head and lower electrode cap respectively, effectively reducing electrode thermal deformation caused by high welding temperature and extending service life.

[0020] 4. The lower electrode integrates an air blowing structure (lower electrode air inlet). During welding, air is blown through the gap of the pneumatic positioning pin to remove metal spatter, avoid thread contamination, ensure the reliability of the connection between the nut and the workpiece, and improve the qualification rate of the welded product. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure after the upper and lower electrodes are separated;

[0022] Figure 2 This is a schematic diagram of the structure after the upper and lower electrodes are assembled.

[0023] Figure 3 This is a schematic diagram of the internal structure of the lower electrode holder;

[0024] Figure 4 A schematic diagram of the internal structure of the upper electrode holder.

[0025] In the diagram: 01 Upper electrode, 02 Lower electrode, 1 Upper electrode base plate, 2 Upper electrode seat, 3 Upper electrode cooling pipe, 4 Upper electrode rod, 5 Upper electrode sleeve, 6 Upper electrode head, 7 Upper electrode insulating ring, 8 Pneumatic positioning pin, 9 Lower electrode cap, 10 Lower electrode sleeve, 11 Water channel sealing ring, 12 Electrode seat steel sleeve, 13 Water channel lower sealing ring, 14 Sensor sensing spring, 15 Positioning pin support spring, 16 Lower electrode seat, 17 Inductive sensor, 18 Lower electrode base plate, 19 Upper electrode water inlet, 20 Upper electrode water outlet, 21 Lower electrode water inlet, 22 Lower electrode water outlet, 23 Lower electrode air inlet. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0027] Reference Figure 1-4 A high-performance, cost-effective projection weld electrode for nut detection includes an upper electrode 01 and a lower electrode 02. The upper electrode 01 includes an upper electrode base plate 1, an upper electrode seat 2, an upper electrode cooling pipe 3, an upper electrode rod 4, an upper electrode head 6, and an upper electrode insulating ring 7. The upper electrode insulating ring 7 is sleeved outside the bottom end of the upper electrode head 6, and the extension length of the upper electrode insulating ring 7 is greater than that of the upper electrode head 6. The upper electrode insulating ring 7 is used to contact the lower electrode to form an open circuit when the nut is misaligned. The lower electrode 02 includes a pneumatic positioning pin 8 and a lower electrode cap 9. The components include: lower electrode sleeve 10, water inlet sealing ring 11, electrode seat steel sleeve 12, water inlet sealing ring 13, sensor sensing spring 14, positioning pin support spring 15, lower electrode seat 16, inductive sensor 17, and lower electrode base plate 18. The pneumatic positioning pin 8 is connected to the lower electrode seat 16 through the positioning pin support spring 15 and is linked with the sensor sensing spring 14. The inductive sensor 17 is installed on the lower electrode base plate 18 to detect the displacement change of the pneumatic positioning pin 8 in order to determine the placement status of the nut.

[0028] When welding 6, the upper electrode head directly contacts the upper end face of the projection welding nut. It is generally machined into a ring structure to concentrate the welding heat and play the role of transmitting current and welding pressure. It is a consumable part and should be replaced according to its wear and deformation after welding a certain number of workpieces.

[0029] The upper electrode insulating ring 7 is outside the upper electrode head 6, and its extension length is longer than that of the upper electrode head 6. On the one hand, it serves to wrap the upper electrode to slow down its deformation speed. On the other hand, if the projection welding nut is not placed correctly, it will cause the welding circuit to be broken, causing the welding controller to report a fault.

[0030] The upper electrode 01 and the lower electrode 02 are each provided with an independent cooling circuit. The cooling circuit of the upper electrode 01 is set on the upper electrode seat 2, and the cooling circuit of the lower electrode 02 is set on the lower electrode seat 16.

[0031] In addition, the upper electrode seat 2 is connected to the bottom of the upper electrode base plate 1. The upper electrode seat 2 is hollow inside. The upper electrode cooling pipe 3 is connected inside the upper electrode seat 2. The upper electrode rod 4 is sleeved on the outside of the upper electrode cooling pipe 3. The upper electrode water inlet 19 is opened on one side wall of the upper electrode seat 2. The upper electrode water outlet 20 is opened below the upper electrode water inlet 19. The upper electrode water inlet 19 and the upper electrode water outlet 20 are the cooling circuit of the upper electrode 01, and both are connected to the inner cavity of the upper electrode seat 2. The upper electrode rod 4 can be inserted into the workpiece to avoid interference.

[0032] Moreover, the upper electrode rod 4 is a slender tube with a central opening. An upper electrode sleeve 5 is provided at the bottom of the upper electrode rod 4. One end of the upper electrode sleeve 5 is connected to the upper electrode rod 4 through a taper, and the other end is connected to the upper electrode head 6 through a taper. When welding, the upper electrode head 6 directly contacts the upper end face of the projection weld nut. The upper electrode sleeve 5 serves as a transition connection and protects the taper of the upper electrode rod.

[0033] Meanwhile, a wiring groove is provided on the lower electrode base plate 18, and the wiring groove of the lower electrode base plate 18 is used to install the inductive sensor 17. A lower electrode seat 16 is installed on the upper surface of the lower electrode base plate 18. A cavity is provided inside the lower electrode seat 16. The top of the lower electrode seat 16 is connected to the lower electrode sleeve 10 by threads. A lower electrode cap 9 is installed on the upper surface of the lower electrode sleeve 10. A through hole is vertically provided in the center of the lower electrode cap 9. A pneumatic positioning pin 8 extends upward from the through hole in the center of the lower electrode cap 9, and the bottom of the pneumatic positioning pin 8 is located in the cavity of the lower electrode seat 16. The lower electrode sleeve 10 is fastened to the lower electrode seat 16 by threads on one side and is also connected to the lower electrode cap 9 by threads on the other side, which serves to lock the electrode seat steel sleeve 12 and protect the lower electrode seat 16.

[0034] Meanwhile, an electrode holder steel sleeve 12 is fitted outside the lower electrode holder 16. A water channel sealing ring 11 is provided on the top of the electrode holder steel sleeve 12 and below the lower electrode sleeve 10. A water channel lower sealing ring 13 is provided at the bottom of the electrode holder steel sleeve 12. The lower electrode holder 16 has a lower electrode water inlet 21 and a lower electrode water outlet 22 symmetrically opened on both sides, which communicate with the internal cavity. A lower electrode air inlet 23, which communicates with the internal cavity of the lower electrode holder 16, is opened on the side adjacent to the lower electrode water inlet 21 and the lower electrode water outlet 22. The lower electrode water inlet 21, the lower electrode water outlet 22, the water channel sealing ring 11, the electrode holder steel sleeve 12, and the water channel lower sealing ring 13 constitute the cooling circuit of the lower electrode 02.

[0035] In addition, a positioning pin support spring 15 is provided at the bottom of the pneumatic positioning pin 8. The bottom of the pneumatic positioning pin 8 abuts against the top of the positioning pin support spring 15, and the bottom of the positioning pin support spring 15 abuts against the bottom wall of the cavity inside the lower electrode seat 16. The sensor sensing spring 14 is installed at the bottom of the pneumatic positioning pin 8 and moves up and down with the pneumatic positioning pin 8. Its length is designed according to the sensing distance of the inductive sensor 17. When the projection welding nut and the workpiece are correctly placed, the descent distance of the pneumatic positioning pin 8 is small, and the sensor sensing spring 14 will not be detected by the inductive sensor 17. When the projection welding nut and the workpiece are not placed correctly and are pressing against the pneumatic positioning pin 8, the descent distance of the pneumatic positioning pin 8 is large, and the sensor sensing spring 14 is detected by the inductive sensor 17. The signal is sent to the welding controller, which reports a fault to notify the customer that the nut or workpiece is not placed correctly.

[0036] In this embodiment, when the nut and the workpiece are correctly positioned, the upper electrode head 6 contacts the top of the projection weld nut, and the lower electrode cap 9 contacts the workpiece to be welded, forming a good power circuit. The current of the welding controller passes through the workpiece and the projection weld nut, forming a weld nugget at the projection point. During welding, the pneumatic positioning pin 8 moves down slightly, and the sensor sensing spring 14 moves down a small distance, so that it will not be detected by the inductive sensor 17. The controller does not report a fault and welding is normal.

[0037] When the projection weld nut is missing, or both the projection weld nut and the workpiece are missing, the upper electrode 01 is pressed down during welding. The upper electrode insulating ring 7 and the lower electrode cap 9 or the workpiece come into contact, but the upper electrode head 6 cannot contact the workpiece or the lower electrode cap 9. The welding conductive circuit is isolated and insulated by the upper electrode insulating ring 7, forming an open circuit. The current output of the welding controller is blocked, and a fault is reported to notify the user to handle the problem.

[0038] When the projection welding nut is placed backwards or improperly, three situations may occur: First, the upper electrode insulating ring 7 presses on the projection welding nut, preventing the projection welding nut from contacting the upper electrode head 6. The welding conductive circuit is isolated and insulated by the upper electrode insulating ring 7, forming an open circuit. During welding, the current output of the welding controller is blocked, and a fault is reported to notify the user to handle the problem. Second, when the projection welding nut or the workpiece is above the pneumatic positioning pin 8, the pneumatic positioning pin 8 descends a large distance. The sensor sensing spring 14 causes the inductive sensor 17 to sense the fault, and the signal is sent to the welding controller, causing it to report a fault and notify the user to handle the problem. Third, both of the above situations exist simultaneously, and the welding controller reports a fault and notifies the user to handle the problem.

[0039] The welding current passing through the electrode during operation is very large, causing the electrode to heat up and thus affecting the welding quality and electrode lifespan. Therefore, the cooling system plays a crucial role in electrode operation. The upper electrode adopts a traditional water cooling method. The upper electrode holder 2 has an upper electrode water inlet 19, an upper electrode water outlet 20, and an upper electrode cooling pipe 3, forming an upper electrode cooling water circulation. Cooling water enters from the upper electrode water inlet 19, is sprayed onto the upper electrode head 6 through the upper electrode cooling pipe 3, and then returns through the upper electrode rod 4 and the cavity of the upper electrode holder 2, flowing out from the upper electrode water outlet 20. Due to its special structure, the lower electrode adopts a surface ring cooling method. The lower electrode holder 16 has a lower electrode water inlet 21, a lower electrode water outlet 22, a water channel sealing ring 11, an electrode holder steel sleeve 12, and a water channel lower sealing ring 13, forming a lower electrode cooling water circulation. Cooling water enters from the lower electrode water inlet 21, circulates around the cold water tank on the lower electrode holder 16, and finally flows out through the lower electrode water outlet 22.

[0040] The lower electrode 02 has an air blowing structure that blows away welding spatter during welding, preventing metal spatter from sticking to the threads of the projection weld nut and preventing the bolt from passing through. When the projection weld nut is correctly positioned for welding, the pneumatic positioning pin 8 moves down slightly, creating a gap in the internal cavity of the lower electrode seat 16. The gas entering through the lower electrode air inlet 23 blows through the gap onto the workpiece and the projection weld nut.

[0041] The electrode sleeve transition design protects the electrode body and reduces the cost of vulnerable electrode components. At the upper electrode 01, one end of the upper electrode sleeve 5 is tapered to the upper electrode rod 4, and the other end is also tapered to the upper electrode head 6, serving as a transition connection and protecting the taper of the upper electrode rod. At the same time, the size of the vulnerable component, the upper electrode head 6, is reduced, thus lowering costs. At the lower electrode 02, one side of the lower electrode sleeve 10 is threadedly fastened to the lower electrode seat 16, and the other side is also threadedly connected to the lower electrode cap 9, serving to protect the lower electrode seat 16. At the same time, the size of the vulnerable component, the lower electrode cap 9, is reduced, thus lowering costs.

[0042] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A cost-effective nut detection projection welding electrode comprising an upper electrode (01), a lower electrode (02), characterized in that, The upper electrode (01) includes an upper electrode base plate (1), an upper electrode seat (2), an upper electrode cooling pipe (3), an upper electrode rod (4), an upper electrode head (6), and an upper electrode insulating ring (7). The upper electrode insulating ring (7) is sleeved on the outside of the bottom end of the upper electrode head (6), and the extension length of the upper electrode insulating ring (7) is greater than that of the upper electrode head (6). The upper electrode insulating ring (7) is used to contact the lower electrode to form an open circuit when the nut is misaligned. The lower electrode (02) includes a pneumatic positioning pin (8), a lower electrode cap (9), a lower electrode sleeve (10), a water channel sealing ring (11), an electrode seat steel sleeve (12), a water channel lower sealing ring (13), a sensor sensing spring (14), a positioning pin support spring (15), a lower electrode seat (16), an inductive sensor (17), and a lower electrode base plate (18). The pneumatic positioning pin (8) is connected to the lower electrode seat (16) through the positioning pin support spring (15) and is linked with the sensor sensing spring (14). The inductive sensor (17) is installed on the lower electrode base plate (18) and is used to detect the displacement change of the pneumatic positioning pin (8) to determine the placement status of the nut. The upper electrode (01) and the lower electrode (02) are each provided with an independent cooling circuit. The cooling circuit of the upper electrode (01) is set on the upper electrode seat (2), and the cooling circuit of the lower electrode (02) is set on the lower electrode seat (16).

2. The cost-effective projection weld electrode with a nut detection according to claim 1, characterized in that, The upper electrode seat (2) is located at the bottom of the upper electrode base plate (1). The upper electrode seat (2) is hollow inside. The upper electrode cooling pipe (3) is connected inside the upper electrode seat (2). The upper electrode rod (4) is sleeved on the outside of the upper electrode cooling pipe (3).

3. The high-performance, cost-effective projection weld electrode with nut as described in claim 2, characterized in that, The upper electrode base (2) has an upper electrode water inlet (19) on one side wall and an upper electrode water outlet (20) below the upper electrode water inlet (19). The upper electrode water inlet (19) and the upper electrode water outlet (20) are the cooling circuits of the upper electrode (01) and are both connected to the inner cavity of the upper electrode base (2).

4. The cost-effective projection weld electrode with a nut detection according to claim 2, characterized in that The upper electrode rod (4) is a slender tube with a central opening. An upper electrode sleeve (5) is provided at the bottom of the upper electrode rod (4). One end of the upper electrode sleeve (5) is connected to the upper electrode rod (4) through a taper, and the other end is connected to the upper electrode head (6) through a taper. The upper electrode head (6) is in direct contact with the upper surface of the projection weld nut during welding.

5. The cost-effective projection weld electrode with a threaded nut of claim 1, wherein, The lower electrode base plate (18) is provided with a wiring groove. The wiring groove of the lower electrode base plate (18) is used to install an inductive sensor (17). The lower electrode base (16) is installed on the upper surface of the lower electrode base plate (18). The lower electrode base (16) has a cavity inside. The top of the lower electrode base (16) is connected to the lower electrode sleeve (10) by a thread. The lower electrode cap (9) is installed on the upper surface of the lower electrode sleeve (10). The lower electrode cap (9) has a through hole vertically opened in the center. The pneumatic positioning pin (8) extends upward from the through hole in the center of the lower electrode cap (9), and the bottom of the pneumatic positioning pin (8) is located in the cavity of the lower electrode base (16).

6. A cost-effective projection weld electrode with a nut detection according to claim 5, characterized in that The lower electrode holder (16) is fitted with an electrode holder steel sleeve (12). A water passage sealing ring (11) is provided on the top of the electrode holder steel sleeve (12) and below the lower electrode holder (10). A water passage lower sealing ring (13) is provided at the bottom of the electrode holder steel sleeve (12).

7. The cost-effective projection weld electrode with a threaded nut of claim 5, wherein, The lower electrode base (16) has a lower electrode water inlet (21) and a lower electrode water outlet (22) symmetrically opened on both sides, which are connected to the internal cavity of the lower electrode base (16). The lower electrode water inlet (21) and the lower electrode water outlet (22) are adjacent to each other and have a lower electrode air inlet (23) connected to the internal cavity of the lower electrode base (16). The lower electrode water inlet (21), the lower electrode water outlet (22), the water passage sealing ring (11), the electrode base steel sleeve (12), and the water passage lower sealing ring (13) constitute the cooling circuit of the lower electrode (02).

8. The cost-effective projection weld electrode with a threaded nut of claim 5, wherein, The bottom of the pneumatic positioning pin (8) is provided with a positioning pin support spring (15). The bottom of the pneumatic positioning pin (8) abuts against the top of the positioning pin support spring (15), and the bottom of the positioning pin support spring (15) abuts against the bottom wall of the cavity inside the lower electrode seat (16). The sensor sensing spring (14) is installed at the bottom of the pneumatic positioning pin (8) and moves up and down with the pneumatic positioning pin (8). Its length is designed according to the sensing distance of the inductive sensor (17).

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