Servo robot welding pliers for medium and large sheet metal parts

Abstract

The invention relates to the technical field of welding tongs, in particular to servo robot welding tongs for medium and large sheet metal parts, which comprise a servo welding tongs seat, a driving motor, a hydraulic rod, an electrode welding rod and a polishing assembly, a rotating claw is rotatably mounted on the servo welding tongs seat, the end part of the hydraulic rod is rotatably connected with the rotating claw, the driving motor is fixedly mounted at the end part of the rotating claw, and the electrode welding rod is rotatably connected with the driving motor. An electrode welding rod is rotationally installed on the driving motor, an electrode tip is installed at the end of the electrode welding rod, the grinding assembly is arranged on the servo electrode holder base, and the transmission assembly drives the grinding assembly to work. According to the servo electrode holder, the grinding assembly is installed on the servo electrode holder base, the grinding assembly grinds the electrode tip which does not work, the defects of welding explosion, small welding nugget and the like caused by the fact that the electrode tip cannot be ground in time in the using process are overcome, the welding quality of a welding part is improved, and the welding efficiency and the welding quality stability of the electrode holder are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of welding tongs, in particular to a servo robot welding tongs for medium and large sheet metal parts. Background Art

[0002] Sheet metal is a comprehensive cold processing technology for thin metal plates, including shearing, punching / cutting / combining, folding, welding, riveting, splicing, forming, etc. Its notable feature is that the thickness of the same part is consistent. The products processed by sheet metal technology are called sheet metal parts. From the perspective of manufacturing technology, sheet metal parts are mostly formed and fixed by welding. Since the thickness of the plate used in sheet metal parts is relatively thin, it is not conducive to the use of conventional arc welding, gas shielded arc welding, etc. Considering the shape of sheet metal parts, the difficulty of production, and benefits, the most ideal way is to adopt the "resistance welding" welding mode with the advantages of short heating time, concentrated heat, small heat-affected zone, small deformation and stress, and low welding cost. Resistance welding is the spot welding of sheet metal parts using a servo robot welding clamp: the metal sheets to be connected are overlapped together, the welding gun applies pressure through the upper and lower electrodes to clamp them, and the welding transformer applies a certain welding current to the clamping part. When the current passes through the welding area, a certain resistance heat is generated to melt the parent material at the clamping part. After cooling under the continuous action of the electrode pressure, the welded materials are combined together by the binding force between the metal atoms to form a solid weld. The function of the electrode head is mainly to transfer the heat and pressure required for the welding part, and at the same time dissipate the heat in the welding area, which is the key factor in determining whether there are defects in the weld. The electrode head often needs to be ground during use to ensure the welding quality of the welding clamp.

[0003] In order to avoid the electrode head not being repaired in time during use, which will cause defects in the weld and affect the welding quality of the welding tongs, the invention patent with application number CN202021064755.5 provides a servo welding tongs automatic grinder, which is provided by setting a support frame, a motor is clamped in the support frame, the bottom end of the motor is fixedly connected to the lower surface of the inner wall of the support frame, a first gear is clamped on the outer wall of the output end of the motor, and a cross plate is provided on the inner wall of the support frame, and the left and right sides of the cross plate are respectively fixedly connected to the left and right sides of the inner wall of the support frame, a protective shell, a support rod, a spring and a sleeve rod are provided on the cross plate, and the outer side of the grinding tool can be wrapped by the protective shell. The shielding can prevent the waste chips from splashing during the grinding process, thereby providing protection for the staff, and the support rod can be elastically extended and retracted with the sleeve rod through the action of the spring, which can effectively provide elastic protection for it while ensuring its structural stability. However, the grinder needs to remove the electrode head and grind it manually, and the electrode head generally used for welding medium and large sheet metal parts of automobiles can weld about 200 points at one time. However, for welding workpieces with surface treatment (galvanized plates, thermoformed plates), the grinding frequency of the electrode head is 120 / times, and the grinding frequency is relatively high. If the electrode head needs to be disassembled for grinding all the time, the welding efficiency of the welding clamp will be reduced.

[0004] Therefore, in order to avoid the electrode head not being repaired in time during use, resulting in defects in the weld, affecting the appearance and internal welding quality of the welded parts, and to ensure the welding efficiency of the welding clamp, a servo robot welding clamp for medium and large sheet metal parts is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a servo robot welding tongs for medium and large sheet metal parts. In order to prevent the end face of the electrode head from becoming larger during the spotting process, the surface oxide layer becomes thicker and thicker, which reduces the current density, increases the resistance of the oxide layer to the current, and does not have enough heat to form a weld core, resulting in defects in the weld point, affecting the appearance and internal quality of the welded part. By installing a grinding assembly on the servo welding tongs seat, when the hydraulic rod drives the rotating claw to open and close, the grinding assembly grinds the electrode head that is not working, so as to avoid the electrode head not being able to be ground in time during use, resulting in defects such as explosion welding and small weld core, thereby improving the welding appearance and internal welding quality of the welded part, and ensuring the welding efficiency of the welding tongs and the stability of welding quality.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A servo robot welding tongs for medium and large sheet metal parts, comprising a servo welding tongs seat, a driving motor, a hydraulic rod, an electrode welding rod, and a grinding assembly, wherein a rotating claw is rotatably mounted on the servo welding tongs seat, the hydraulic rod is mounted on the servo welding tongs seat, the end of the hydraulic rod is rotatably connected to the rotating claw, the hydraulic rod reciprocates in the horizontal direction to drive the rotating claw to limit rotation, the end of the rotating claw is fixedly mounted with a driving motor, an electrode welding rod is rotatably mounted on the driving motor, the electrode welding rod is arranged in a T shape, and welding work can be performed at both ends, an electrode head is mounted on the end of the electrode welding rod, the electrode head performs pressurized welding on the sheet metal part, the grinding assembly is arranged on the servo welding tongs seat and is located on the side of the electrode welding rod, a transmission assembly is fixedly mounted on the hydraulic rod, and the hydraulic rod transmits power to the grinding assembly through the transmission assembly to grind the other end of the electrode head that has not been welded.

[0008] By rotating the rotating claw installed on the servo welding clamp seat, the rotating claw rotates counterclockwise to a limited position when the hydraulic rod moves to the left, and the relative distance between the two electrode heads increases. When the hydraulic rod moves to the right, the rotating claw rotates clockwise to a limited position, and the relative distance between the two electrode heads decreases. The horizontal reciprocating motion of the hydraulic rod controls the opening and closing of the rotating claw. When the rotating claw opens, the electrode head moves and positions. After the positioning is completed, the rotating claw closes. The electrode heads at the upper and lower ends of the sheet metal apply pressure to the sheet metal to perform spot welding. When the T-shaped electrode welding rod is working, the electrode head close to one end of the grinding assembly is not energized, and the transmission assembly moves with the hydraulic rod when the hydraulic rod is working. The hydraulic rod reciprocates in the horizontal direction, and the power of the hydraulic rod is transmitted to the grinding assembly by the transmission assembly. The grinding assembly rotates and grinds the electrode head that is not powered on. When the number of electrode head tapping times reaches the set number, the driving motor rotates the motor electrode 180°, and the positions of the two electrode heads are interchanged. The grinding assembly can grind the used electrode head to avoid defects in the weld due to failure to timely grind the electrode head during use, thereby ensuring the welding appearance and internal welding quality of the welded part. In addition, the servo welding clamp can synchronously grind the non-working electrode head while working, thereby improving the welding efficiency of servo welding.

[0009] Preferably, the grinding assembly includes a grinding frame, a rotating gear, a rack, a rotating frame, sandpaper, and a cylindrical roller. The grinding frame is fixedly mounted on the servo welding clamp seat, and the rotating frame is arranged at the end of the grinding frame. The rotating frame is rotatably connected to the grinding frame through a rotating rod and is located on the side of the electrode welding rod. A rotating gear is fixedly mounted on the rotating frame, and the rack is fixedly mounted on the transmission assembly. The rotating gear is meshed with the rack. Three cylindrical rollers are installed in the rotating frame, and the three cylindrical rollers can rotate along their own axes. The sandpaper is sleeved on the three cylindrical rollers. When the rotating claw is limited and rotated during the electric welding operation, the non-working electrode head is fitted with the sandpaper. A rotating assembly is arranged in the rotating frame, and the rotating assembly causes the sandpaper to rotate on the cylindrical roller.

[0010] The grinding frame is fixedly installed on the servo welding clamp seat, the grinding frame is set to an L shape, and one end of the grinding frame extends above the electrode welding rod. A rotating frame is rotatably installed on this side. The rotating frame is rectangular when viewed from the front and has a U-shaped cross-section when viewed from the side. It is rotatably connected to the grinding frame through a rotating rod. When the grinding assembly grinds the electrode head, the electrode head is located in the U-shaped opening. The rotating gear is installed on the top of the rotating frame and is fixedly connected to the rotating rod. When the rotating gear rotates, it drives the entire rotating frame to rotate. The rack extends from the transmission assembly to the top of the rotating frame. Inside the grinding frame, when the hydraulic rod reciprocates in the horizontal direction, the rack reciprocates with the hydraulic rod, and the rack drives the rotating gear The rotating gear rotates throughout a whole circle. While the hydraulic rod reciprocates, the rotating claw opens and closes, and the electrode electrode rotates tiltedly. The electrode head abuts against the sandpaper surface. After the sandpaper wraps the end face of the electrode head, the rotating frame rotates to drive the entire sandpaper to rotate and grind the electrode head. The sandpaper grinds the oxide layer generated during the spotting process of the electrode head to prevent the end face of the electrode head from becoming larger and the surface oxide layer from becoming thicker, which reduces the current density. The increase in the thickness of the oxide layer will also increase the resistance of the spot welding current, resulting in insufficient heat to form a weld core, causing defects such as weld explosion, deviation, and small weld core. Automatic grinding of the oxide layer improves the stability of the welding quality of the welding clamp and reduces the labor intensity of the staff.

[0011] Preferably, the rotating assembly includes a cylindrical rod, a worm wheel, and a worm, the cylindrical rod passes through the rotating frame and is fixedly connected to the grinding frame, the worm wheel is rotatably installed on the end of the cylindrical rod, the end face of the worm wheel is parallel to the end face of the rotating frame, the worm is rotatably installed inside the rotating frame, the surface of the worm is in contact with the sandpaper, the worm wheel is meshed with the worm, a serrated groove is provided on the worm wheel, a rotating clip is fixedly installed inside the rotating frame, the rotating clip is configured as an arc sheet, when the rotating clip rotates clockwise, the end of the rotating clip abuts against the protruding end face of the serrated groove, and when the rotating clip rotates counterclockwise, the end of the rotating clip and the protruding end face of the serrated groove slide relative to each other.

[0012] By arranging a rotating assembly in the rotating frame, the cylindrical rod is coaxial with the rotating rod. Since the cylindrical rod passes through the rotating frame and is fixedly connected to the grinding frame, the cylindrical rod will remain relatively still when the rotating frame rotates, and the worm wheel will not rotate either. When the rotating frame is driven by the rack to rotate as a whole, the rotating clip will rotate coaxially with the rotating gear, and the end of the rotating clip will be stuck in the raised part of the sawtooth groove, driving the worm wheel to rotate. The rotation of the worm wheel drives the worm to rotate. Under the influence of friction, the rotation of the worm will cause the sandpaper to rotate on the cylindrical roller. When the hydraulic rod When moving to the left, the surface of the rotating clamping strip will slide relative to the raised part of the serrated groove, and the rotating clamping strip cannot drive the worm wheel to rotate. When the hydraulic rod moves to the right, the end face of the rotating clamping strip will be stuck in the raised part of the serrated groove, driving the worm to rotate. When the hydraulic rod reciprocates, the unidirectional rotation of the worm wheel and worm is guaranteed, and the unidirectional rotation of the sandpaper is also guaranteed. The unidirectional rotation of the sandpaper enables multiple grinding surfaces to be fully utilized, avoiding excessive use of a part of the sandpaper resulting in reduced friction and inability to grind the oxide layer, thereby improving the grinding effect of the grinding component.

[0013] Preferably, the line connecting the axes of the three cylindrical rollers on the horizontal plane is a triangle, and the layout of the three cylindrical rollers can be divided into the highest installation position, the middle installation position, and the lowest installation position, and the cross-section of the sandpaper mounted on the cylindrical rollers forms an inclined angle with the end face of the rotating frame.

[0014] By setting the layout positions of the three cylindrical rollers, the sandpaper sleeved on the cylindrical rollers is triangular in cross section, and the sandpaper on the surface in contact with the electrode head is inclined to the bottom surface of the rotating frame, so that when the electrode electrode rotates, the contact area between the sandpaper and the electrode head is increased. When the sandpaper rotates, it can cover the oxide layer on the electrode head, thereby improving the cleaning effect of the sandpaper on the oxide layer.

[0015] Preferably, a key groove is provided on the inner wall of the rotating frame, and the cylindrical roller at the highest installation position can slide in the key groove. A rectangular plate is fixedly installed on the side of the key groove, and a support spring is vertically fixedly installed on the rectangular plate, and one end of the support spring applies thrust to the cylindrical roller.

[0016] By setting the cylindrical roller at the highest installation position to slide in the key groove, when the grinding assembly is not working, the cylindrical roller at the highest installation position is located at one end of the key groove under the thrust of the supporting spring, and the sandpaper is stretched out. When the electrode head abuts and fits the sandpaper, due to the weak flexibility of the sandpaper, the supporting spring is compressed under the action of the abutting thrust of the electrode head, and the cylindrical roller at the highest installation position moves within the key groove, and the cross-sectional shape of the sandpaper changes, thereby increasing the contact area between the sandpaper surface and the electrode head, and further improving the grinding effect.

[0017] Preferably, an arc support plate is provided below the cylindrical roller at the highest installation position, the arc support plate is in contact with the surface of the cylindrical roller, and the bottom of the arc support plate is fixedly connected to the support spring.

[0018] An arc support plate is arranged under the cylindrical roller at the highest installation position, and the arc support plate moves with the cylindrical roller. The arc support plate enables the thrust of the supporting spring to be evenly applied to the cylindrical roller, thereby preventing the cylindrical roller from tilting left and right when moving, causing the sandpaper to be unable to fully fit the electrode head, and improving the stability of the grinding assembly.

[0019] Preferably, a frame baffle is fixedly installed inside the rotating frame, and the frame baffle is set to a U shape. The frame baffle is located on the side of the cylindrical roller at the middle installation position. When the rotating claw rotates, the horizontal position of the top of the non-working electrode head is higher than the bottom horizontal position of the frame baffle.

[0020] By fixing a frame baffle inside the rotating frame, when the electrode head abuts against the sandpaper surface to change the shape of the sandpaper, the frame baffle will abut against the sandpaper on one side of the electrode head, making the sandpaper on that side more inclined, thereby increasing the contact area between the sandpaper and the electrode head, increasing the covering area of ​​the sandpaper on the oxide layer, and further improving the cleaning effect of the sandpaper on the oxide layer.

[0021] Preferably, a sliding groove is provided on the grinding frame, a support rod is fixedly mounted on the rack, the support rod is arranged in a T-shape, the support rod is slidably matched with the sliding groove, and the support rod slides within the sliding groove in a limited position when the hydraulic rod reciprocates.

[0022] By arranging the sliding cooperation between the support rod and the slide groove, the support points of the rack during movement are increased, the bending stress on the rack during movement is reduced, the service life of the rack is increased, and the stability of the grinding assembly is improved.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. By setting the transmission assembly to reciprocate in the horizontal direction with the hydraulic rod when the hydraulic rod is working, the power of the hydraulic rod is transmitted to the grinding assembly by the transmission assembly. The grinding assembly rotates and grinds the electrode head that is not powered on, so as to avoid the electrode head not being repaired in time during use, resulting in defects in the weld, thereby ensuring the welding appearance and internal welding quality of the welded parts. In addition, the servo welding clamp can synchronously grind the electrode head that is not working while working, thereby improving the welding efficiency of servo welding.

[0025] 2. The rotating frame is rotated to drive the entire sandpaper to rotate and grind the electrode head. The sandpaper grinds the oxide layer generated during the spotting process of the electrode head to prevent the end face of the electrode head from becoming larger and larger during the spotting process. The surface oxide layer becomes thicker and thicker, which reduces the current density. The increase in the thickness of the oxide layer will also increase the resistance of the spot welding current, resulting in insufficient heat to form a weld nugget, causing defects such as welding explosion, deviation, and small weld nugget. Automatic grinding of the oxide layer improves the stability of the welding quality of the welding clamp and reduces the labor intensity of the staff.

[0026] 3. By setting the unidirectional rotation of the worm gear, the unidirectional rotation of the sandpaper is ensured. The unidirectional rotation of the sandpaper enables multiple grinding surfaces to be fully utilized, avoiding excessive use of a part of the sandpaper resulting in reduced friction and inability to grind the oxide layer of the electrode head, thereby improving the grinding effect of the grinding assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the appearance structure of the present invention;

[0028] Figure 2 It is a structural front view of the present invention;

[0029] Figure 3 It is a schematic diagram of the rotation of the electrode welding rod of the present invention;

[0030] Figure 4 This is a schematic diagram of the limited rotation of the rotating claw of the present invention;

[0031] Figure 5 It is a schematic diagram of the structure of the grinding assembly of the present invention;

[0032] Figure 6 It is a cutaway front view of the grinding assembly of the present invention;

[0033] Figure 7 It is a schematic diagram of the rotating assembly of the present invention;

[0034] Figure 8 This is a schematic diagram of the electrode head of the present invention being attached to sandpaper.

[0035] In the figure: 1. servo welding clamp seat; 2. driving motor; 3. hydraulic rod; 31. transmission assembly; 4. electrode rod; 41. electrode head; 5. grinding assembly; 51. grinding frame; 511. sliding groove; 52. rotating gear; 53. rack; 531. support rod; 54. rotating frame; 541. rotating rod; 542. rotating clamping strip; 543. key groove; 544. rectangular plate; 545. support spring; 55. sandpaper; 56. cylindrical roller; 6. rotating claw; 7. rotating assembly; 71. cylindrical rod; 72. worm wheel; 73. worm; 74. serrated groove; 8. arc support plate; 9. frame baffle. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it is necessary to understand that the terms "horizontal", "relative", "upper", "lower", "coaxial", "side", "fit" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0038] See also Figures 1 to 8 The present invention provides a servo robot welding clamp for medium and large sheet metal parts, and the technical solution is as follows:

[0039] The servo welding clamp seat 1 is installed on the mechanical arm, and the movement and positioning of the servo welding clamp seat 1 are driven by the mechanical arm. A rotating claw 6 is rotatably installed on the servo welding clamp seat 1. A hydraulic rod 3 is installed on the servo welding clamp seat 1. The end of the hydraulic rod 3 is rotatably connected with the rotating claw 6. The hydraulic rod 3 reciprocates in the horizontal direction to drive the rotating claw 6 to rotate. A driving motor 2 is fixedly installed on the end of the rotating claw 6. An electrode welding rod 4 is rotatably installed on the driving motor 2. The electrode welding rod 4 is set in a T shape, and welding work can be performed at both ends. An electrode head 41 is installed on the end of the electrode welding rod 4. An electrode electrode 4 is also arranged below the movable claw 6, that is, at one end of the servo welding clamp seat 1. The electrode head 41 performs pressurized welding on the sheet metal. The grinding assembly 5 is arranged on the servo welding clamp seat 1. A transmission assembly 31 is fixedly installed on the hydraulic rod 3. The transmission assembly 31 drives the grinding assembly 5 to work. When the electrode head 41 performs electric welding, the grinding assembly 5 grinds the electrode head 41 at the other end that is not performing electric welding. When the hydraulic rod 3 moves to the left, the rotating claw 6 rotates counterclockwise to a limited position, and the relative distance between the two electrode heads 41 increases. When the hydraulic rod 3 moves to the right, the rotating claw 6 rotates clockwise to a limited position. When the hydraulic rod 3 rotates, the relative distance between the two electrode heads 41 decreases, and the horizontal reciprocating motion of the hydraulic rod 3 controls the opening and closing of the rotating claw 6. When the rotating claw 6 opens, the electrode head 41 moves to position. After the positioning is completed, the rotating claw 6 closes, and the electrode heads 41 at the upper and lower ends of the sheet metal apply pressure to the sheet metal to perform spot welding. When the T-shaped electrode welding rod 4 is working, the electrode head 41 near one end of the grinding component 5 is not energized. When the hydraulic rod 3 is working, the transmission component 31 reciprocates in the horizontal direction with the hydraulic rod 3, and the power of the hydraulic rod 3 is transmitted from the transmission component 31 to the grinding component 5. The grinding assembly 5 rotates and grinds the electrode head 41 that is not powered. When the number of times the electrode head 41 is marked reaches the set number, the motor 2 is driven to rotate the motor electrode 180°, and the positions of the two electrode heads 41 are interchanged. The grinding assembly 5 can grind the used electrode head 41 to avoid the electrode head 41 not being repaired in time during use, resulting in defects in the weld, thereby ensuring the welding appearance and internal welding quality of the welded part. The servo welding clamp can synchronously grind the electrode head 41 that is not working while working, thereby improving the welding efficiency of the servo welding.The grinding assembly 5 includes a grinding frame 51, a rotating gear 52, a rack 53, a rotating frame 54, sandpaper 55, and a cylindrical roller 56. The grinding frame 51 is fixedly mounted on the servo welding clamp seat 1. The rotating frame 54 is arranged at the end of the grinding frame 51. The rotating frame 54 is rotatably connected to the grinding frame 51 through a rotating rod 541 and is located on the side of the electrode electrode 4. The rotating frame 54 is fixedly mounted with a rotating gear 52. The rack 53 is fixedly mounted on the transmission assembly 31. The rotating gear 52 is meshed with the rack 53. Three cylindrical rollers 56 are installed in the rotating frame 54. The three cylindrical rollers 56 can rotate along their own axes. The sandpaper 55 is sleeved on the three cylindrical rollers 56. When the rotating claw 6 is limited and rotated during the electric welding operation, the electrode head 41 that is not working and the sandpaper 55 fits, a rotating assembly 7 is arranged in the rotating frame 54, and the rotating assembly 7 makes the sandpaper 55 rotate on the cylindrical roller 56. The grinding frame 51 is arranged in an L shape, and one end of the grinding frame 51 extends to the top of the electrode electrode 4. The rotating frame 54 is rotatably installed on this side. The rotating frame 54 is rectangular when viewed from the front, and has a U-shaped cross-section when viewed from the side. It is rotatably connected to the grinding frame 51 through a rotating rod 541. When the grinding assembly 5 grinds the electrode head 41, the electrode head 41 is located in the U-shaped opening. The rotating gear 52 is installed on the top of the rotating frame 54 and is fixedly connected to the rotating rod 541. When the rotating gear 52 rotates, it drives the entire rotating frame 54 to rotate. The rack 53 extends from the transmission assembly 31 to the top of the rotating frame 54. And inside the grinding frame 51, when the hydraulic rod 3 reciprocates in the horizontal direction, the rack 53 reciprocates with the hydraulic rod 3, and the rack 53 drives the rotating gear 52 to make a full circle of rotation. While the hydraulic rod 3 reciprocates, the rotating claw 6 opens and closes, and the electrode welding rod 4 rotates tiltedly, and the electrode head 41 abuts against the sandpaper 55 surface. After the sandpaper 55 wraps the end face of the electrode head 41, the rotating frame 54 rotates to drive the entire sandpaper 55 to rotate and grind the electrode head 41. The sandpaper 55 grinds the oxide layer generated during the spotting process of the electrode head 41 to prevent the end face of the electrode head 41 from becoming larger and the surface oxide layer from becoming thicker during the spotting process, which reduces the current density. The increase in the thickness of the oxide layer will also increase the resistance of the spot welding current, resulting in insufficient heat. The amount of weld nuggets formed will cause defects such as weld explosion, offset, and small weld nuggets. The automatic grinding of the oxide layer improves the stability of the welding quality of the welding tongs and reduces the labor intensity of the staff. The line connecting the axes of the three cylindrical rollers 56 on the horizontal plane is a triangle. The layout of the three cylindrical rollers 56 can be divided into the highest installation position, the middle installation position, and the lowest installation position. The cross section of the sandpaper 55 sleeved on the cylindrical roller 56 forms an inclined angle with the end face of the rotating frame 54. The sandpaper 55 sleeved on the cylindrical roller 56 is triangular in cross section, and the sandpaper 55 on the contact surface with the electrode head 41 is inclined to the bottom surface of the rotating frame 54, so that when the electrode electrode 4 rotates, the contact area between the sandpaper 55 and the electrode head 41 is increased, further improving the grinding effect of the grinding assembly 5. ;

[0040] As an embodiment of the present invention, refer to Figures 5 to 8The rotating assembly 7 includes a cylindrical rod 71, a worm wheel 72, and a worm 73. The cylindrical rod 71 passes through the rotating frame 54 and is fixedly connected to the grinding frame 51. The worm wheel 72 is rotatably mounted on the end of the cylindrical rod 71. The end face of the worm wheel 72 is parallel to the end face of the rotating frame 54. The worm 73 is rotatably mounted inside the rotating frame 54. The surface of the worm 73 fits the sandpaper 55. The worm wheel 72 meshes with the worm 73. A sawtooth groove 74 is provided on the worm wheel 72. A rotating clip 542 is fixedly installed inside the rotating frame 54. The rotating clip 542 is configured as an arc sheet. The rotating clip 542 is made of an elastic spring sheet. The rotating clip 542 is slidably matched with the sawtooth groove 74. The cylindrical rod 71 and the rotating rod 541 The cylindrical rod 71 passes through the rotating frame 54 and is fixedly connected to the grinding frame 51. Therefore, when the rotating frame 54 rotates, the cylindrical rod 71 will remain relatively still, and the worm gear 72 will not rotate. When the rotating frame 54 is driven by the rack 53 to rotate as a whole, the rotating clamping strip 542 will rotate coaxially with the rotating gear 52. The end of the rotating clamping strip 542 will be stuck in the raised part of the sawtooth groove 74, driving the worm wheel 72 to rotate. The rotation of the worm wheel 72 drives the worm 73 to rotate. Under the influence of friction, the rotation of the worm 73 will cause the sandpaper 55 to rotate on the cylindrical roller 56. When the hydraulic rod 3 moves to the left, the surface of the rotating clamping strip 542 will slide relative to the raised part of the sawtooth groove 74. The strip 542 cannot drive the worm wheel 72 to rotate. When the hydraulic rod 3 moves to the right, the end face of the rotating clamping strip 542 will be stuck in the raised part of the serrated groove 74, driving the worm 73 to rotate. When the hydraulic rod 3 reciprocates, the unidirectional rotation of the worm wheel 72 and the worm 73 is guaranteed. At the same time, the unidirectional rotation of the sandpaper 55 is also guaranteed. The unidirectional rotation of the sandpaper 55 makes full use of multiple grinding surfaces, avoids excessive use of a part of the sandpaper 55, resulting in reduced friction and inability to grind the oxide layer, and improves the grinding effect of the grinding assembly 5; a key groove 543 is provided on the inner wall of the rotating frame 54, and the cylindrical roller 56 at the highest installation position can slide in the key groove 543. A rectangular plate 544 is vertically fixed with a support spring 545, one end of the support spring 545 applies a thrust to the cylindrical roller 56. When the grinding assembly 5 is not working, the cylindrical roller 56 at the highest installation position is at one end of the key groove 543 under the thrust of the support spring 545, and the sandpaper 55 is stretched open. When the electrode head 41 abuts and fits the sandpaper 55, due to the weak flexibility of the sandpaper 55, under the action of the abutment thrust of the electrode head 41, the support spring 545 is compressed, and the cylindrical roller 56 at the highest installation position moves within the key groove 543. The cross-sectional shape of the sandpaper 55 changes, thereby increasing the contact area between the sandpaper 55 surface and the electrode head 41, and further improving the grinding effect.An arc support plate 8 is arranged below the cylindrical roller 56 at the highest installation position, and the arc support plate 8 is fitted with the surface of the cylindrical roller 56. The bottom of the arc support plate 8 is fixedly connected to the support spring 545, and the arc support plate 8 moves with the cylindrical roller 56. The arc support plate 8 makes the thrust of the support spring 545 evenly applied to the cylindrical roller 56 to prevent the cylindrical roller 56 from tilting left and right when moving, resulting in the sandpaper 55 not being able to fully fit with the electrode head 41, thereby improving the stability of the grinding assembly 5; a frame baffle 9 is fixedly installed inside the rotating frame 54, and the frame baffle 9 is set in a U shape. The frame baffle 9 is located on the side of the cylindrical roller 56 at the middle installation position. When the electrode head 41 fits with the sandpaper 55, the inside of the sandpaper 55 fits with the end of the frame baffle 9. When the head 41 abuts against the sandpaper 55 surface to change the shape of the sandpaper 55, the frame baffle 9 will abut against the sandpaper 55 on one side of the electrode head 41, making the sandpaper 55 on this side more inclined, increasing the contact area between the sandpaper 55 and the electrode head 41, and further improving the grinding effect of the sandpaper 55; a sliding groove 511 is provided on the grinding frame 51, and a support rod 531 is fixedly installed on the rack 53. The support rod 531 is set in a T shape. The support rod 531 slides with the sliding groove 511. When the hydraulic rod 3 reciprocates, the support rod 531 slides in the sliding groove 511, increasing the support points of the rack 53 when it moves, reducing the bending stress of the rack 53 when it moves, increasing the service life of the rack 53, and improving the stability of the grinding assembly 5. ;

[0041] Working principle: when the hydraulic rod 3 moves to the left, the rotating claw 6 rotates counterclockwise to a limited position, and the relative distance between the two electrode heads 41 increases; when the hydraulic rod 3 moves to the right, the rotating claw 6 rotates clockwise to a limited position, and the relative distance between the two electrode heads 41 decreases; the horizontal reciprocating motion of the hydraulic rod 3 controls the opening and closing of the rotating claw 6; when the rotating claw 6 opens, the electrode head 41 moves to a position; after the positioning is completed, the rotating claw 6 closes; the electrode heads 41 at the upper and lower ends of the sheet metal apply pressure to the sheet metal to perform spot welding; when the hydraulic rod 3 reciprocates in the horizontal direction, the rack 53 reciprocates with the hydraulic rod 3, the support rod 531 slides within the sliding groove 511, and the rack 53 drives the rotating gear 52 to rotate a full circle; while the hydraulic rod 3 reciprocates, the rotating claw 6 opens and closes, and the electrode electrode 4 rotates tiltedly; the electrode head 41 abuts and fits against the sandpaper 55 surface; when the electrode head 41 abuts Under the action of the connecting thrust, the supporting spring 545 is compressed, and the cylindrical roller 56 at the highest installation position moves within the key groove 543, and the cross-sectional shape of the sandpaper 55 changes. At this time, the frame baffle 9 will press against the sandpaper 55 on one side of the electrode head 41, making the sandpaper 55 on this side more inclined, thereby increasing the contact area between the sandpaper 55 and the electrode head 41. After the sandpaper 55 wraps the end face of the electrode head 41, the rotating frame 54 rotates to drive the entire sandpaper 55 to rotate and grind the electrode head 41. When the hydraulic rod 3 moves to the left, the surface of the rotating clamping strip 542 will slide relative to the raised part of the serrated groove 74, and the rotating clamping strip 542 cannot drive the worm wheel 72 to rotate. When the hydraulic rod 3 moves to the right, the end face of the rotating clamping strip 542 will be stuck in the raised part of the serrated groove 74, driving the worm 73 to rotate. The rotation of the worm 73 drives the sandpaper 55 to rotate, thereby changing the grinding surface of the sandpaper 55.

[0042] A specific embodiment of the present invention is described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above described embodiment. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments without departing from the principles and ideas of the present invention should still fall within the scope of protection of the present invention.

Claims

1. A servo robot welding tongs for medium and large sheet metal parts, characterized in that: The invention comprises a servo welding clamp seat (1), a driving motor (2), a hydraulic rod (3), an electrode welding rod (4), and a grinding assembly (5); a rotating claw (6) is rotatably mounted on the servo welding clamp seat (1); the hydraulic rod (3) is mounted on the servo welding clamp seat (1); the end of the hydraulic rod (3) is rotatably connected to the rotating claw (6); the hydraulic rod (3) reciprocates in the horizontal direction to drive the rotating claw (6) to rotate in a limited position; the end of the rotating claw (6) is fixedly mounted with a driving motor (2); and the electrode welding rod (4) is rotatably mounted on the driving motor (2). The electrode welding rod (4) is arranged in a T-shape and can be welded at both ends. An electrode head (41) is installed at the end of the electrode welding rod (4). The electrode head (41) performs pressure welding on the sheet metal. The grinding assembly (5) is arranged on the servo welding clamp seat (1) and is located on the side of the electrode welding rod (4). The transmission assembly (31) is fixedly installed on the hydraulic rod (3). The hydraulic rod (3) transmits power to the grinding assembly (5) through the transmission assembly (31) to grind the other end of the electrode head (41) that is not subjected to electric welding.

2. The servo robot welding tongs for medium and large sheet metal parts according to claim 1, characterized in that: The grinding assembly (5) comprises a grinding frame (51), a rotating gear (52), a rack (53), a rotating frame (54), sandpaper (55), and a cylindrical roller (56). The grinding frame (51) is fixedly mounted on the servo welding clamp seat (1). The rotating frame (54) is arranged at the end of the grinding frame (51). The rotating frame (54) is rotatably connected to the grinding frame (51) through a rotating rod (541) and is located on the side of the electrode electrode (4). The rotating frame (54) is fixedly mounted with a rotating gear (52). The rack (53) is fixedly mounted on the rotating frame (54). The rotating gear (52) is meshed with the rack (53), three cylindrical rollers (56) are installed in the rotating frame (54), and the three cylindrical rollers (56) can rotate along their own axes. The sandpaper (55) is sleeved on the three cylindrical rollers (56). When the rotating claw (6) is limitedly rotated during the electric welding operation, the electrode head (41) that is not in operation is in contact with the sandpaper (55). A rotating assembly (7) is arranged in the rotating frame (54), and the rotating assembly (7) causes the sandpaper (55) to rotate on the cylindrical rollers (56).

3. The servo robot welding tongs for medium and large sheet metal parts according to claim 2, characterized in that: The rotating assembly (7) comprises a cylindrical rod (71), a worm wheel (72), and a worm (73); the cylindrical rod (71) passes through a rotating frame (54) and is fixedly connected to the grinding frame (51); the worm wheel (72) is rotatably mounted on the end of the cylindrical rod (71); the end surface of the worm wheel (72) is parallel to the end surface of the rotating frame (54); the worm (73) is rotatably mounted inside the rotating frame (54); the surface of the worm (73) is in contact with the sandpaper (55); the worm wheel (72) is in contact with the grinding frame (51); The worm (73) is meshed, a sawtooth groove (74) is provided on the worm wheel (72), a rotating clip (542) is fixedly installed inside the rotating frame (54), and the rotating clip (542) is arranged in the shape of a circular arc sheet. When the rotating clip (542) rotates clockwise, the end of the rotating clip (542) abuts against the protruding end surface of the sawtooth groove (74), and when the rotating clip (542) rotates counterclockwise, the end of the rotating clip (542) and the protruding end surface of the sawtooth groove (74) slide relative to each other.

4. The servo robot welding tongs for medium and large sheet metal parts according to claim 3, characterized in that: The connecting line of the axes of the three cylindrical rollers (56) on the horizontal plane is a triangle, and the layout of the three cylindrical rollers (56) can be divided into a highest installation position, a middle installation position, and a lowest installation position. The cross section of the sandpaper (55) sleeved on the cylindrical rollers (56) forms an inclined angle with the end surface of the rotating frame (54).

5. The servo robot welding tongs for medium and large sheet metal parts according to claim 4, characterized in that: A key-shaped groove (543) is provided on the inner side wall of the rotating frame (54), and the cylindrical roller (56) at the highest installation position can slide in the key-shaped groove (543). A rectangular plate (544) is fixedly installed on the side of the key-shaped groove (543), and a support spring (545) is vertically fixedly installed on the rectangular plate (544), and one end of the support spring (545) applies a thrust to the cylindrical roller (56).

6. The servo robot welding tongs for medium and large sheet metal parts according to claim 5, characterized in that: An arc support plate (8) is arranged below the cylindrical roller (56) at the highest installation position. The arc support plate (8) is in contact with the surface of the cylindrical roller (56), and the bottom of the arc support plate (8) is fixedly connected to the support spring (545).

7. The servo robot welding tongs for medium and large sheet metal parts according to claim 5, characterized in that: A frame baffle (9) is fixedly installed inside the rotating frame (54), and the frame baffle (9) is set in a U shape. The frame baffle (9) is located on the side of the cylindrical roller (56) at the middle installation position. When the rotating claw (6) rotates, the horizontal position of the top of the non-working electrode head (41) is higher than the horizontal position of the bottom of the frame baffle (9).

8. The servo robot welding tongs for medium and large sheet metal parts according to claim 2, characterized in that: The grinding frame (51) is provided with a sliding groove (511), the rack (53) is fixedly mounted with a support rod (531), the support rod (531) is arranged in a T-shape, the support rod (531) is slidably matched with the sliding groove (511), and the support rod (531) slides in a limited position in the sliding groove (511) when the hydraulic rod (3) reciprocates.

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