Spot welding mechanism and system for thermistor metal wires

Abstract

The invention relates to the technical field of welding, in particular to a thermistor metal wire spot welding mechanism and system.The thermistor metal wire spot welding mechanism comprises a spot welding base table, a pointed electrode and a column electrode, and the pointed electrode and the column electrode are arranged on the spot welding base table and can stretch out and draw back; the lower die can move in the radial direction of the pointed electrode and the column electrode; when the metal wire and the Dumet wire of the thermistor are spot-welded, the metal wire and the Dumet wire do not need to be stabilized by hand, the Dumet wire is matched with the inner wall of the end face side groove to clamp the metal wire, then the metal wire is horizontally bent for spot welding, and the contact tightness and absolute stability of the metal wire and the Dumet wire in the spot welding process can be guaranteed.

Description

Technical Field

[0001] This invention relates to the field of welding technology, specifically to a mechanism and system for spot welding thermistor wires. Background Technology

[0002] Beaded glass-encapsulated thermistors possess excellent properties such as high temperature resistance, vibration resistance, extreme temperature resistance, and long-term reliability and stability, and are widely used in automotive electronics, industrial control, medical equipment, aerospace and other fields. The main production process is as follows: dispensing (applying the resistive paste to parallel metal wires) — high-temperature sintering — spot welding (spot welding the metal wires to Dummes wires using spot welding equipment) — glass encapsulation.

[0003] In the spot welding process, the traditional operation mode is purely manual. One hand holds the metal wire with tweezers, and the other hand holds the Dummey wire. First, the Dummey wire is placed on the column electrode, then the metal wire is overlapped on the Dummey wire, and finally the metal wire and Dummey wire are spot welded together by discharge through the pointed electrode. This method requires both hands to be held steadily without shaking, which requires a very high level of skill from the operator, has a long on-the-job training period, and the spot welding position of the metal wire and Dummey wire is inconsistent, resulting in low production quality. Summary of the Invention

[0004] The purpose of this invention is to provide a thermistor wire spot welding mechanism and system to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a spot welding mechanism for a thermistor wire, comprising a spot welding base, and a pointed electrode and a cylindrical electrode that are telescopically movable and disposed on the spot welding base. A lower mold is also disposed on the spot welding base, and the lower mold is capable of radial movement along the pointed electrode and the cylindrical electrode. An upper mold is disposed above the lower mold, and a positioning wire groove is formed on the upper surface of the lower mold. During the spot welding process, the Dummey wire is placed in the positioning wire groove and is pressed down and limited by the upper mold. An ejector is provided on one side of the lower mold. The mechanism includes an ejector mechanism that corresponds one-to-one with the positioning wire groove, which drives the Dume wire to move axially. The end of the column electrode has an end face side groove, which is open on one side in the horizontal direction and has its inner wall perpendicular to the horizontal plane on the other side. The depth of the end face side groove is less than the diameter of the Dume wire. During spot welding, one end of the metal wire is first inserted into the end face side groove, and the ejector mechanism drives the Dume wire to move axially, so that the Dume wire and the inner wall of the end face side groove cooperate to clamp the metal wire. Then, the metal wire is bent horizontally and spot welded through the pointed electrode.

[0006] The ejection mechanism includes a mold push hole and a drive ejector pin. The mold push hole is opened in the lower mold and corresponds one-to-one with the positioning wire groove. The drive ejector pin is inserted inside the mold push hole. When the drive ejector pin moves axially, it can push the Dume wire in the positioning wire groove axially.

[0007] An electromagnetic back plate is fixedly provided at the end of the drive pin, and a track frame is fixedly provided on the surface of the lower mold. The electromagnetic back plate is slidably limited within the track frame.

[0008] The surface of the lower mold is embedded with a return spring and an electromagnet unit. The return spring applies a pushing force to the electromagnetic back plate, causing the drive pin to tend to move away from the positioning screw groove. When the electromagnet unit is energized, it can magnetically attract the electromagnetic back plate, causing the drive pin to overcome the elastic force of the return spring and move into the positioning screw groove.

[0009] The lower surface of the upper mold is fixedly provided with a pressing rib. The upper mold is inserted into the positioning wire groove through the pressing rib to press down and limit the Dume wire in the positioning wire groove.

[0010] The lower pressing rib has a rib break groove, and the lower mold has a lower break groove that extends laterally through the positioning thread groove. An arc-shaped rotating sleeve is fixedly installed on the inner wall of the lower break groove. The arc-shaped rotating sleeve is an arc-shaped bent plate, and an independent rotating column is rotatably installed inside the arc-shaped rotating sleeve. The independent rotating column corresponds one-to-one with the positioning thread groove. The arc-shaped rotating sleeve limits the independent rotating column, so that the independent rotating column can only rotate within the arc-shaped rotating sleeve.

[0011] When the Dumes is placed in the positioning groove and pressed into place by the pressing rib, the independent rotating column is coaxial with the Dumes.

[0012] The independent rotating column has a central cavity, and rectangular end slots are symmetrically formed at both ends. The central cavity and the rectangular end slots are interconnected. A curved spring section is symmetrically arranged inside the central cavity, and a vertical clamping plate is fixedly mounted on the curved spring section. The vertical clamping plate is flush with the side wall of the rectangular end slot. A sloping inner pressure block is fixedly mounted at the connection between the curved spring section and the vertical clamping plate. The sloping inner pressure block has a sloping surface. When the independent rotating column rotates in the arc-shaped rotating sleeve, the sloping inner pressure block first presses against the arc-shaped rotating sleeve through the sloping surface, causing the sloping inner pressure block to move inward. At this time, the curved spring section elastically deforms, and the vertical clamping plate protrudes from the inner wall of the rectangular end slot, clamping the Dumex wire.

[0013] The outer surface of the independent rotating column is provided with a central ring tooth, and a synchronous drive rack is engaged below the central ring tooth. An electrically controlled telescopic device is fixedly installed on the outside of the lower mold, and an L-shaped telescopic component is provided on the electrically controlled telescopic device. The L-shaped telescopic component is fixed to the synchronous drive rack. The electrically controlled telescopic device drives the L-shaped telescopic component to extend and retract, causing the synchronous drive rack to reciprocate. At this time, the independent rotating column reciprocates within a preset angle. An upper and lower vibrator is fixedly installed on the upper mold, and the upper and lower vibrator can apply vibration impact perpendicular to the horizontal plane to the upper mold.

[0014] A spot welding system includes a thermistor wire spot welding mechanism and a power supply module, the power supply module being used to supply power to pointed electrodes and cylindrical electrodes to achieve spot welding.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This invention relates to a spot welding mechanism for thermistor wires. Through the cooperation of end-face side slotting, lower mold, and ejection mechanism, it is possible to spot weld the thermistor wire and Dumme wire without holding and stabilizing the wire by hand. The wire is clamped by the Dumme wire and the inner wall of the end-face side slot, and then the wire is bent horizontally for spot welding. This ensures the tight contact and absolute stability of the wire and Dumme wire during the spot welding process, improves the spot welding quality and the uniformity of the spot welding position, significantly reduces the skill requirements for workers, and reduces the time required for on-the-job training.

[0016] This invention, through the combination of a downward pressure rib, upper and lower vibrators, and an independent rotating column, can pre-straighten the Dume wire, making it easier to eject during subsequent spot welding. The downward pressure of the downward pressure rib in conjunction with the upper and lower vibrators, and the rotation of the Dume wire by the independent rotating column during the process, can straighten the Dume wire in multiple directions.

[0017] This invention, through the combination of independent rotating columns, vertical clamping plates, and inclined inner pressure blocks, enables the independent rotating columns to clamp the Dumex wires automatically in confined spaces by simply driving them to rotate at a certain angle. This allows the Dumex wires to rotate under the impact of the downward pressing ribs, thus improving the straightening effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0019] Figure 2 This is another schematic diagram of the overall structure of the present invention.

[0020] Figure 3 This is a schematic diagram of mold separation in this invention.

[0021] Figure 4 This is a schematic diagram of the lower mold of the present invention.

[0022] Figure 5 This is a three-dimensional half-sectional schematic diagram of the present invention.

[0023] Figure 6 This is a partial three-dimensional cross-sectional view of the cylindrical electrode of the present invention.

[0024] Figure 7 This is a partial three-dimensional cross-sectional view of the electromagnetic backplate of the present invention.

[0025] Figure 8 This is a three-dimensional half-section diagram of the lower groove of the present invention.

[0026] Figure 9 This is a partial three-dimensional cross-sectional view of the independent rotating column of the present invention.

[0027] Figure 10 This is a schematic diagram of the independent rotating column of the present invention.

[0028] Figure 11 This is a three-dimensional half-section diagram of the independent rotating column of the present invention.

[0029] In the diagram: 1. Spot welding base; 2. Pointed electrode; 3. Column electrode; 4. Lower mold; 5. Upper mold; 6. Positioning screw groove; 7. End face side slot; 401. Mold push hole; 402. Drive ejector pin; 403. Electromagnetic back plate; 404. Track outer frame; 405. Return spring; 406. Electromagnet unit; 8. Lower pressure rib; 801. Rib groove break; 802. Lower groove break; 803. Arc-shaped rotating sleeve; 804. Independent rotating column; 805. Middle cavity groove; 806. Rectangular end groove; 807 808. Curved spring plate; 809. Vertical clamping plate; 810. Inclined inner pressure block; 811. Intermediate ring tooth; 812. Synchronous drive rack; 813. L-shaped telescopic component; 814. Electrically controlled telescopic device; 815. Upper and lower vibrators; 106. Track optical axis; 107. Lead screw shaft; 108. Optical axis sliding sleeve; 109. Lead screw thread sleeve; 1000. Servo driver; 201. Upper telescopic controller; 301. Lower telescopic controller; 407. Extension nozzle; 501. Pre-positioning hole; 502. Pre-positioning shaft. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figures 1 to 11This invention provides a technical solution: a spot welding mechanism for a thermistor wire, comprising a spot welding base 1, and a pointed electrode 2 and a cylindrical electrode 3 disposed on the spot welding base 1 and capable of telescopic movement, such as... Figure 1 As shown, an upper telescopic controller 201 and a lower telescopic controller 301 are fixedly installed on the spot welding base 1. The upper telescopic controller 201 enables the pointed electrode 2 to move up and down, and the lower telescopic controller 301 enables the column electrode 3 to move up and down. The upper telescopic controller 201 and the lower telescopic controller 301 have the same internal structure and can both achieve linear drive by using rack and pinion gears.

[0032] The pointed electrode 2 and the cylindrical electrode 3 are made of high-temperature resistant alloys such as cerium-tungsten and tungsten-copper. During spot welding, the pointed electrode 2 and the cylindrical electrode 3 can be prevented from melting, thereby preventing the pointed electrode 2 and the cylindrical electrode 3 from sticking to the Dummes wire and the metal wire.

[0033] The spot welding base 1 is also equipped with a lower mold 4; such as Figure 2 As shown, a track optical shaft 101 is fixedly installed on the spot welding base 1. An optical shaft sleeve 103 and a lead screw sleeve 104 are welded to the lower surface of the lower mold 4. The optical shaft sleeve 103 is fitted outside the track optical shaft 101, so that the lower mold 4 is stably supported and can slide along the axial direction of the track optical shaft 101. A lead screw shaft 102 is also rotatably installed on the spot welding base 1. The lead screw shaft 102 passes through the lead screw sleeve 104, and there is a helical engagement between the lead screw shaft 102 and the lead screw sleeve 104. Thus, when the lead screw shaft 102 rotates, it can drive the lower mold 4 to slide along the axial direction of the track optical shaft 101 through the helical engagement with the lead screw sleeve 104. A servo driver 105 is also fixedly installed on the spot welding base 1. The servo driver 105 is composed of a servo motor and a speed gear set. The servo driver 105 drives the lead screw shaft 102, so that the lower mold 4 can move radially along the pointed electrode 2 and the column electrode 3.

[0034] An upper mold 5 is also provided above the lower mold 4. A positioning thread groove 6 is provided on the upper surface of the lower mold 4, such as... Figure 4 As shown, the positioning wire grooves 6 are arranged in several groups and are evenly distributed in a linear array. During the spot welding process, the Dummey wire is placed in the positioning wire grooves 6 and is pressed down and limited by the upper mold 5; as Figure 2 As shown, a pre-positioning hole 501 is provided through the upper and lower surfaces of the upper mold 5, and a pre-positioning shaft 502 is welded and fixedly installed on the upper surface of the lower mold 4. When the upper mold 5 and the lower mold 4 are engaged, positioning is achieved first by limiting the position through the pre-positioning hole 501 and the pre-positioning shaft 502. An ejection mechanism is provided on one side of the lower mold 4, and the ejection mechanism corresponds one-to-one with the positioning screw groove 6. The ejection mechanism can drive the Dumesh wire to move axially. like Figure 6As shown, the end of the column electrode 3 is provided with an end face side groove 7. The end face side groove 7 is open on one side in the horizontal direction, and the inner wall of the other side is perpendicular to the horizontal plane. The depth of the end face side groove 7 is less than the diameter of the Dume wire. During spot welding, one end of the metal wire is first inserted into the end face side groove 7. The ejection mechanism drives the Dume wire to move axially, so that the Dume wire and the inner wall of the end face side groove 7 cooperate to clamp the metal wire. Then the metal wire is bent horizontally and spot welded through the pointed electrode 2.

[0035] Dummes is a metal composite wire specifically designed for glass sealing. The metal wire described in this invention is typically a platinum wire. Dummes connects to the core of the temperature-sensing resistor via the platinum wire, which can prevent vibration or temperature changes from affecting the core of the temperature-sensing resistor.

[0036] The ejection mechanism includes a mold push hole 401 and a drive ejector pin 402. The mold push hole 401 is opened in the lower mold 4, and the mold push hole 401 corresponds one-to-one with the positioning wire groove 6. The drive ejector pin 402 is inserted inside the mold push hole 401. When the drive ejector pin 402 moves axially, it can push the Dume wire in the positioning wire groove 6 axially.

[0037] An electromagnetic back plate 403 is fixedly provided at the end of the drive ejector pin 402, and a track frame 404 is fixedly provided on the surface of the lower mold 4. The electromagnetic back plate 403 is slidably limited in the track frame 404.

[0038] The surface of the lower mold 4 is embedded with a return spring 405 and an electromagnet unit 406. The return spring 405 applies a pushing force to the electromagnetic back plate 403, causing the drive pin 402 to tend to move away from the positioning screw groove 6. When the electromagnet unit 406 is energized, it can magnetically attract the electromagnetic back plate 403, causing the drive pin 402 to overcome the elastic force of the return spring 405 and move into the positioning screw groove 6.

[0039] like Figure 4 and Figure 6 As shown, an extension nozzle 407 is fixedly provided on the side surface of the lower mold 4. The extension nozzle 407 corresponds to the position of the positioning wire groove 6. The extension nozzle 407 increases the distance between the lower mold 4 and the column electrode 3, which facilitates the operation of the metal wire and Dummey wire.

[0040] A pressing rib 8 is fixedly provided on the lower surface of the upper mold 5. The upper mold 5 inserts the pressing rib 8 into the positioning wire groove 6 to press down and limit the Dume wire in the positioning wire groove 6. A rib break groove 801 is opened on the pressing rib 8, and a lower break groove 802 is opened in the lower mold 4. The lower break groove 802 passes through the positioning wire groove 6 laterally. An arc-shaped rotating sleeve 803 is fixedly provided on the inner wall of the lower break groove 802. The arc-shaped rotating sleeve 803 is an arc-shaped bent plate, and an independent rotating column 804 is rotatably arranged inside the arc-shaped rotating sleeve 803. The independent rotating column 804 corresponds one-to-one with the positioning wire groove 6. The arc-shaped rotating sleeve 803 limits the independent rotating column 804, so that the independent rotating column 804 can only rotate in the arc-shaped rotating sleeve 803.

[0041] When the Dumes is placed in the positioning groove 6 and pressed into place by the pressing rib 8, the independent rotating column 804 is coaxial with the Dumes.

[0042] The independent rotating column 804 has a central cavity groove 805 inside, and rectangular end grooves 806 are symmetrically opened at both ends of the independent rotating column 804. The central cavity groove 805 and the rectangular end grooves 806 are connected to each other. The central cavity 805 is symmetrically provided with curved spring parts 807. A vertical clamping plate 808 is fixedly provided on the curved spring parts 807. The vertical clamping plate 808 is flush with the side wall of the rectangular end groove 806. An inclined inner pressure block 809 is fixedly provided at the connection between the curved spring parts 807 and the vertical clamping plate 808. An inclined surface is provided on the inclined inner pressure block 809. When the independent rotating column 804 rotates in the arc-shaped rotating sleeve 803, the inclined inner pressure block 809 first squeezes against the arc-shaped rotating sleeve 803 through the inclined surface, causing the inclined inner pressure block 809 to move inward. At this time, the curved spring parts 807 elastically deform, and the vertical clamping plate 808 protrudes from the inner wall of the rectangular end groove 806 to clamp the Dumex wire.

[0043] The outer surface of the independent rotating column 804 is provided with a middle ring tooth 810, and a synchronous drive rack 811 is engaged below the middle ring tooth 810. An electrically controlled telescopic device 813 is fixedly installed on the outside of the lower mold 4. An L-shaped telescopic member 812 is provided on the electrically controlled telescopic device 813. The L-shaped telescopic member 812 is fixed with the synchronous drive rack 811. The electrically controlled telescopic device 813 drives the L-shaped telescopic member 812 to extend and retract, so that the synchronous drive rack 811 moves back and forth. At this time, the independent rotating column 804 rotates back and forth within a preset angle. The electrically controlled telescopic device 813 can be composed of a motor and a gear rack structure, or it can be composed of an electromagnet and a spring structure. The electrically controlled telescopic device 813 only needs to be able to achieve reciprocating drive, which will not be described in detail in this invention.

[0044] The upper mold 5 is fixedly equipped with an upper and lower vibrator 814. The upper and lower vibrator 814 can apply vibration impact perpendicular to the horizontal plane to the upper mold 5. The upper and lower vibrator 814 can be composed of an electromagnet, a spring and a ferromagnetic counterweight. By inputting an intermittent pulse current to the electromagnet, the electromagnet generates an intermittent magnetic force, which intermittently attracts the ferromagnetic counterweight. With the support of the spring, the upper and lower vibrator 814 can apply vibration impact perpendicular to the horizontal plane to the upper mold 5.

[0045] A spot welding system includes a thermistor wire spot welding mechanism and a power supply module. The power supply module supplies power to a pointed electrode 2 and a cylindrical electrode 3 to achieve spot welding. The power supply module includes a charging transformer, an energy storage capacitor, and a discharging transformer. The charging transformer converts the mains voltage into a voltage suitable for charging the capacitor. The energy storage capacitor is the core component of the capacitor energy storage spot welding machine. It stores electrical energy and releases it instantaneously during welding to form the large current required for welding thin wires. The discharging transformer further converts the electrical energy released by the energy storage capacitor into a low-voltage, high-current to ensure instantaneous melting and formation of a weld point, adapting to the rapid welding requirements of Dumme wire and platinum wire.

[0046] In this invention, during spot welding, the Dume wire is filled into the positioning wire groove 6, and is held and limited by the insertion of the lower rib 8 into the positioning wire groove 6. During operation, the worker only needs to insert the end of the metal wire into the end face slot 7 with tweezers, and press the corresponding control button to energize the electromagnet unit 406 to generate magnetic force. Figure 7 As shown, the electromagnet unit 406 magnetically attracts the electromagnetic back plate 403, causing the electromagnetic back plate 403 to move to the left, driving the drive pin 402 to insert into the positioning wire groove 6. The drive pin 402 presses against the end of the Dume wire, pushing the Dume wire to overcome the contact friction force brought by the positioning wire groove 6 and the pressing rib 8, causing the Dume wire to move to the left.

[0047] Reference Figure 5 and Figure 6 As shown, since the end of the metal wire is inserted into the end face slot 7, when the Dumesh wire moves to the left, it will engage with the inner wall of the end face slot 7 to clamp the metal wire. At this time, when the metal wire is flattened to a horizontal state, the part of the metal wire inside the end face slot 7 remains vertical, as shown. Figure 6 As shown, the pointed electrode 2 is controlled to move downwards, and spot welding is performed at the contact position of the metal wire and the Dumme wire. During the above process, the worker's hands do not need to be kept stable. The worker only needs to insert the metal wire into the end face side slot 7. During spot welding, the metal wire and the Dumme wire are in close contact, which improves the spot welding quality and ensures that the spot welding position is uniform.

[0048] After one spot welding is completed, the column electrode 3 moves down, causing the metal wire and Dume wire to detach from the end face side slot 7. Then the lower mold 4 moves a certain distance along the track optical axis 101, so that the column electrode 3 corresponds to the position of the Dume wire in the next positioning wire groove 6. The column electrode 3 then moves up to reset, and the welding operation is repeated.

[0049] In the above process, if the Dumesh wire is bent, it will affect the axial movement of the Dumesh wire or the holding effect on the metal wire. This invention can straighten the Dumesh wire and energize the upper and lower vibrators 814, causing the upper mold 5 to generate vibration impact perpendicular to the horizontal plane. At this time, the lower pressing rib 8 will cause the Dumesh wire in the positioning wire groove 6 to vibrate and impact at high frequency. At the same time, the L-shaped telescopic member 812 is driven to reciprocate through the electric telescopic device 813, which causes the synchronous drive rack 811 to reciprocate, driving the independent rotating column 804 to reciprocate within a certain angle range. Figure 9 As shown in the image.

[0050] like Figure 9 and Figure 11 As shown, when the independent rotating column 804 reciprocates within a certain angle range, once the independent rotating column 804 rotates, either of the two symmetrical inclined inner pressure blocks 809 will first press against the arc-shaped rotating sleeve 803. Guided by the inclined surface on the inclined inner pressure block 809, the inclined inner pressure block 809 is pushed inward. At this time, the arc-shaped spring piece 807 bends and deforms, while the vertical clamping plate 808 protrudes from the inner wall of the rectangular end groove 806. Through the cooperation between the vertical clamping plate 808 and the inner wall of the rectangular end groove 806 on the other side, the Dumes wire is clamped. As the independent rotating column 804 continues to rotate, it can clamp the Dumes wire and drive the Dumes wire to rotate. Combined with the impact of the downward pressing rib 8, the Dumes wire is straightened in multiple directions. The same applies when rotating in the opposite direction.

[0051] By simply driving the independent rotating column 804 to rotate at a certain angle, the independent rotating column 804 can automatically complete the clamping and engagement of the Dumes wire, so that the Dumes wire can rotate under the impact of the downward pressing rib 8, thereby improving the straightening effect.

[0052] When the electronically controlled telescopic device 813 stops reciprocating the L-shaped telescopic component 812, the synchronous drive rack 811 returns to its initial position. In the initial position, the openings of the rectangular end slot 806 and the middle cavity slot 805 face upwards, thus not affecting the insertion of the Dumees into the positioning wire slot 6.

[0053] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A spot welding mechanism for a thermistor wire, comprising a spot welding base, and a pointed electrode and a cylindrical electrode disposed on the spot welding base and capable of telescopic movement, characterized in that: The spot welding base is also provided with a lower mold, which can move radially along the pointed electrode and the column electrode; An upper mold is also provided above the lower mold. The upper surface of the lower mold is provided with positioning wire grooves. During the spot welding process, the Dume wire is placed in the positioning wire grooves and is pressed down and limited by the upper mold. An ejection mechanism is provided on one side of the lower mold. The ejection mechanism corresponds one-to-one with the positioning wire grooves and can drive the Dume wire to move axially. The end of the column electrode has an end face side groove. The end face side groove is open on one side in the horizontal direction, and the inner wall of the other side is perpendicular to the horizontal plane. The depth of the end face side groove is less than the diameter of the Dume wire. During spot welding, one end of the metal wire is first inserted into the end face side groove. The ejection mechanism drives the Dume wire to move axially, so that the Dume wire and the inner wall of the end face side groove cooperate to clamp the metal wire. Then the metal wire is bent horizontally and spot welded through the pointed electrode.

2. The thermistor wire spot welding mechanism according to claim 1, characterized in that: The ejection mechanism includes a mold push hole and a drive ejector pin. The mold push hole is opened in the lower mold and corresponds one-to-one with the positioning wire groove. The drive ejector pin is inserted inside the mold push hole. When the drive ejector pin moves axially, it can push the Dume wire in the positioning wire groove axially.

3. The thermistor wire spot welding mechanism according to claim 2, characterized in that: An electromagnetic back plate is fixedly provided at the end of the drive pin, and a track frame is fixedly provided on the surface of the lower mold. The electromagnetic back plate is slidably limited within the track frame.

4. A metal wire spot welding mechanism for a thermistor according to claim 3, characterized in that: The surface of the lower mold is embedded with a return spring and an electromagnet unit. The return spring applies a pushing force to the electromagnetic back plate, causing the drive pin to tend to move away from the positioning screw groove. When the electromagnet unit is energized, it can magnetically attract the electromagnetic back plate, causing the drive pin to overcome the elastic force of the return spring and move into the positioning screw groove.

5. A metal wire spot welding mechanism for a thermistor according to claim 1, characterized in that: The lower surface of the upper mold is fixedly provided with a pressing rib. The upper mold is inserted into the positioning wire groove through the pressing rib to press down and limit the Dume wire in the positioning wire groove.

6. A metal wire spot welding mechanism for a thermistor according to claim 5, characterized in that: The lower pressing rib has a rib break groove, and the lower mold has a lower break groove, which transversely penetrates the positioning wire groove. An arc-shaped rotating sleeve is fixedly installed on the inner wall of the lower broken groove. The arc-shaped rotating sleeve is an arc-shaped bent plate, and an independent rotating column is rotatably installed inside the arc-shaped rotating sleeve. The independent rotating column corresponds one-to-one with the positioning screw groove. The arc-shaped rotating sleeve limits the independent rotating column so that the independent rotating column can only rotate in the arc-shaped rotating sleeve.

7. A metal wire spot welding mechanism for a thermistor according to claim 6, characterized in that: When the Dumes is placed in the positioning groove and pressed into place by the pressing rib, the independent rotating column is coaxial with the Dumes.

8. A metal wire spot welding mechanism for a thermistor according to claim 6, characterized in that: The independent rotating column has a central cavity groove inside, and rectangular end grooves are symmetrically opened at both ends of the independent rotating column. The central cavity groove and the rectangular end grooves are interconnected. The central cavity is symmetrically equipped with curved spring pieces, and a vertical clamping plate is fixedly mounted on the curved spring pieces. The vertical clamping plate is flush with the side wall of the rectangular end slot. An inclined inner pressure block is fixedly mounted at the connection between the curved spring pieces and the vertical clamping plate. The inclined inner pressure block has an inclined surface. When the independent rotating column rotates in the arc-shaped rotating sleeve, the inclined inner pressure block first squeezes against the arc-shaped rotating sleeve through the inclined surface, causing the inclined inner pressure block to push inward. At this time, the curved spring pieces undergo elastic deformation, and the vertical clamping plate protrudes from the inner wall of the rectangular end slot, clamping the Dumex wire.

9. A metal wire spot welding mechanism for a thermistor according to claim 8, characterized in that: The outer surface of the independent rotating column is provided with a middle ring tooth, and a synchronous drive rack is engaged below the middle ring tooth. An electric control telescopic device is fixedly installed on the outside of the lower mold. An L-shaped telescopic component is provided on the electric control telescopic device. The L-shaped telescopic component is fixed to the synchronous drive rack. The electric control telescopic device drives the L-shaped telescopic component to extend and retract, so that the synchronous drive rack moves back and forth. At this time, the independent rotating column rotates back and forth within a preset angle. The upper mold is fixedly equipped with upper and lower vibrators, which can apply vibration impact to the upper mold in a direction perpendicular to the horizontal plane.

10. A spot welding system, characterized in that, The system includes a thermistor wire spot welding mechanism and a power supply module as described in any one of claims 1-9, wherein the power supply module is used to supply power to the pointed electrode and the column electrode to achieve spot welding.

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