An automatic dresser for resistance spot welding electrodes

Abstract

The application relates to an automatic grinder for resistance spot welding electrodes, which comprises a closed shell composed of a left shell and a right shell in mirror image relation, and the main functional structure parts of electrode grinding, cutting displacement control and electrode grinding angle compensation are arranged in the closed shell. The application adopts a multiple-blade combined tool public rotation + high-speed rotation mode to mill and grind the electrode, and the working surface of the ground electrode is a plane; under the condition of small electrode pressure, the electrode surface to be ground is positioned and slightly milled and ground; the electrode grinding angle can be compensated according to the flexure of the welding tongs arm, the axial vibration of the tool in the grinding process is effectively inhibited, and sufficient contact between the working surface of the electrode and the surface of the workpiece during welding is ensured. The grinding principle of the application can achieve remarkable positive effects in prolonging the service life of the tool, greatly compressing the unnecessary cutting amount of the electrode, improving the spot welding quality and reducing the spot welding process cost.

Description

Technical Field

[0001] This invention relates to process equipment for grinding resistance spot welding electrodes, and more particularly to an automatic grinding device for resistance spot welding electrodes. Background Technology

[0002] During continuous spot welding, the electrode working surface condition gradually deteriorates with increasing weld number due to the cyclical effects of harsh processes such as high temperature and high pressure. This negative impact on weld quality and spot welding costs gradually increases. To mitigate the greater negative impact caused by excessive changes in the electrode working surface condition, production adopts a method of periodically grinding the electrode working ends. This aims to limit the diameter and surface condition of the electrode working ends within a certain fluctuation range, thereby constraining the weld quality dispersion within an acceptable range.

[0003] The electrode regrinding tool is primarily intended to achieve the following objectives: First, to restore the enlarged working diameter of the electrode surface to its initial set value, creating the necessary conditions for controlling the weld nugget diameter; second, to remove the newly formed oxide layer on the electrode working surface during the previous spot welding process, creating the necessary conditions for improving weld quality and reducing spot welding process costs; and third, to ensure that the working surfaces of the two electrodes after regrinding are parallel to the workpiece surface during spot welding, increasing the effective contact area and current feeding capability between the electrode working surface and the workpiece surface, thus creating the necessary conditions for improving weld quality and reducing spot welding process costs.

[0004] The known automatic electrode grinding devices have the following main shortcomings:

[0005] (1) The grinding principles of known automatic electrode grinding devices are similar and have the following common attributes: First, since the outer contour shape of the cutting edge profile of the tool used for grinding or shaping the electrode working surface is an arc, the initial state of the electrode working surface after grinding is an arc surface with the same radius of curvature as the cutting edge. This greatly reduces the contact ratio between the electrode working surface and the workpiece surface and the actual power supply capability, promotes the accelerated formation of oxides on the electrode working surface, and directly has a negative impact on the quality assurance of the weld. Second, none of them have the ability to compensate for the deflection of the electrode working surface caused by the bending deformation of the welding clamp arm and the tilt angle of the electrode grip during spot welding. During continuous spot welding, the power supply capability of the electrode working surface and the quality assurance of the weld continue to have a negative impact.

[0006] (2) When the electrode is refurbished or shaped, the nature of the tool edge refurbishing the electrode surface is either scraping or a combination of squeezing and scraping. Sufficient pressure must be provided to the tool edge to achieve the purpose of scraping or shaping, thus limiting the working life of the tool. The scraping force or shaping force of the tool edge refurbishing the electrode is jointly established by the electrode pressure and the tool rotation torque. The scraping force or shaping force and the amount of each refurbishment are positively correlated with the dulling of the tool edge. If it is intended to ensure that the new layer formed on the electrode surface can be effectively removed each time it is refurbished, the unnecessary cutting amount must be set large enough. Summary of the Invention

[0007] In view of the above-mentioned problems in the prior art, the main objective of the present invention is to provide an automatic grinding device for resistance spot welding electrodes, which can simultaneously and automatically grind the electrodes on both sides of the automatic welding clamp for various resistance spot welding. In addition to ensuring that the working surface of the ground electrode matches the process requirements during spot welding, it also has the corresponding compensation capability for the deflection angle generated during spot welding of the electrode grip rod. Furthermore, the grinding tool should have a long working life.

[0008] The technical solution of this invention is as follows:

[0009] An automatic regrinding device for resistance spot welding electrodes includes a closed housing consisting of a left housing and a right housing that are mirror images of each other. The main mechanical structure, used for electrode regrinding, cutting displacement control, electrode regrinding angle compensation, and axial vibration suppression of the cutting tool, is housed within the closed housing. A device follow-up swing mechanism, used to balance the cutting stress on both sides during electrode regrinding, is fixedly mounted on a power motor mounting base and the rear surface of the right housing. A negative pressure generator, used to immediately discharge chips generated during electrode regrinding from the electrode regrinding chamber, is fixedly mounted on a device support. During electrode regrinding, the coordinated operation of the main mechanical structure, the device follow-up swing mechanism, and the negative pressure chip removal system simultaneously completes the regrinding of the electrode working ends on the arm handles on both sides of the welding clamp. The main mechanical structure includes a motor-driven regrinding mechanism, wherein:

[0010] The motor grinding mechanism includes a grinding power drive device and two sets of electrode grinding devices. The two sets of electrode grinding devices are coaxially placed on both sides inside the closed housing. The grinding power drive device includes a power motor, a power motor mounting base, a power input gear, a power transition gear, a power input gear bearing, and a power transition gear bearing. The power motor mounting base is fixedly installed on the outer surface of the right housing. The outer rings of the two power input gear bearings and the two power transition gear bearings are respectively fitted into the corresponding bearing holes on the right housing and the power motor mounting base. The left journals of the power input gear and the power transition gear are fitted into the inner rings of the two bearings already placed in the right housing, and the two gears mesh with each other. After the key is fitted into the keyway on the output shaft end of the power motor and the journal of the power input gear, the power motor is fixedly installed on the outer surface of the power motor mounting base with bolts.

[0011] The electrode grinding device is used to grind the working ends of the electrodes on both sides respectively. The electrode grinding device includes a left shell, a right shell, a planetary gear, a left rotating cover, a right rotating cover, a limiting block, a planetary bearing, a combination cutting tool, a fixed gear ring, a toothed plate, a limiting sleeve, an oil-free gasket, and bolts and screws. The outer rings of the two planetary bearings are respectively fitted into the corresponding recesses on the outer surfaces of the left and right shells. The two sealing plates are respectively fitted into the corresponding recesses on the inner surfaces of the left and right shells, and each is fixed to the left and right shells with multiple screws. The outer circle of the fixed gear ring is fitted into the corresponding recess on the inner surface of the left shell, and the fixed gear ring is fixed to the recess on the inner surface of the left shell with multiple bolts. The two limiting blocks are respectively fitted into the recesses on the outer surfaces of the left and right rotating covers, and each is fixed to the left and right rotating covers with multiple screws. At the same time, a limiting set screw is screwed into the threaded hole on the side of each screw.

[0012] After tightly fitting the inner hole of the revolution gear into the corresponding recess on the outer circle of the right turn cover, use multiple screws to fix the tooth guard plate into the corresponding recess on the outer surface of the revolution gear; tightly fit the outer circle of the right turn cover in the right turn cover assembly into the inner circle of the revolution bearing already installed in the right housing; fit the assembled combined cutting tool's shaft end ball bearing into the corresponding recess on the limit block from the inside of the right housing; close the left and right housings, and then complete the following assembly in sequence: fasten the left and right housings together with multiple bolts; fit the outer circle of the left turn cover into the inner hole of the revolution bearing on the left housing, during which the recess hole on the inside of the limit block mates with the outer circle of the shaft end ball bearing on the other side of the combined cutting tool; and fix the left and right turn covers together with multiple bolts.

[0013] The main body of the mechanical structure also includes a cutting displacement control mechanism, which is responsible for controlling the cutting displacement during the grinding of the working ends of the electrodes on both sides and compensating for the grinding angle of the electrodes. The cutting displacement control mechanism includes a set of power drive systems placed inside the closed housing and a cutting displacement control device that connects the inside and outside of the closed housing. The power drive system includes a stepper motor, a reducer, a displacement power input gear, a displacement power transition gear, a synchronization gear, a displacement power input gear bearing, and a displacement transition gear bearing. The cutting displacement control device includes two sets of positive and negative ball thread working pairs composed of two sets of positive and negative ball thread shafts and positive and negative ball thread sleeves, a displacement adjustment gear, a displacement adjustment gear bearing, and two sets of support plate assemblies.

[0014] Two sets each of the displacement power input gear bearing and the displacement power transition gear bearing are respectively fitted into the corresponding bearing holes on the left and right housings. The journals on one side of the displacement power input gear and the displacement power transition gear are respectively inserted into the inner rings of the displacement power input gear bearing and the displacement power transition gear bearing located in the right housing, so that the two gears are in a meshing state.

[0015] Four sets of displacement adjusting gear bearings are respectively fitted into the corresponding bearing holes on the left and right housings. After keying the two positive and negative ball thread shafts with the two displacement adjusting gears, the right journal ends of the two positive and negative ball thread shafts are fitted into the inner ring of the displacement adjusting gear bearing on the right housing. The inner hole of the synchronizing gear is fitted onto the outer circle of the fixed gear ring with clearance fit, and the synchronizing gear meshes with the displacement adjusting gear. At the same time as closing the left and right housings, the displacement power input gear, displacement power transition gear, and the left journal of the positive and negative ball thread shaft are fitted into the corresponding bearing inner ring.

[0016] It also includes a set of combined cutting tools, which comprises a rotating gear, a flat cutting tool, two sets of arc-shaped cutting tools or two sets of frustum-shaped cutting tools, a cutting shaft, two rolling bearings, two disc springs, a needle roller bearing, and pins; the outer circle of the flat cutting tool is tightly fitted and axially symmetrically embedded into the inner hole of the rotating gear; two arc-shaped cutting tools, one helical and one reciprocal, are placed in grooves on both sides of the flat cutting tool, and three pins are inserted into the three corresponding pin holes present in all three tools to establish a torsional engagement relationship between them; the outer circle of the needle roller bearing is... After the round fitting is inserted into the inner hole of the two arc-shaped cutting tools, the cutter shaft is fitted into the inner ring of the needle roller bearing; after installing one disc spring on each side of the axial direction of the cutter shaft, one rolling bearing is fitted into each outside the disc spring; after the combined cutting tool is installed into the closed housing, the axial preload of the disc springs on both sides of the arc-shaped cutting tool is adjusted by the screwing depth of the four limiting set screws evenly distributed on the positioning block, in order to restrain the axial vibration that may be generated by the cutting reaction force when the flat cutting tool and the arc-shaped cutting tool are grinding the electrode.

[0017] The planar cutting tool has a thin-walled circular ring with symmetrical convex rings on both sides of its outer circumference. A through hole with clearance fit between the center and the outer diameter of the needle roller bearing is formed. The surfaces of the two convex rings on both sides are parallel planes with forward and reverse rotating cutting edges respectively. Three through pin holes are symmetrically formed in the grooves on the inner side of the axial convex rings, corresponding to the positions of the three pin holes formed on the bottom surface of the arc-shaped cutting tool. When grinding the electrodes, the rotating plane of the cutting edges on both sides of the planar cutting tool is always in contact with the working end plane of the electrodes to be ground on both sides, and only undertakes the milling and grinding of the working end plane of the electrodes on both sides.

[0018] The cutting displacement control mechanism also includes two sets of support plate assemblies. Each set of support plate assemblies consists of a support plate, an oil-free gasket, a limiting sleeve, a limiting plate, and bolts. The two oil-free gaskets are respectively fitted into the corresponding countersunk holes on the inner side of the two support plates, passing through the inner holes of the two oil-free gaskets, and a limiting sleeve is inserted into each. A limiting plate is fastened to the upper part of each limiting sleeve with two bolts. The positive and negative ball nut holes on both sides of the assembled two sets of support plate assemblies are respectively fitted onto the outer diameter of the positive and negative ball nuts in the ball nut screw pairs on both sides of the closed housing, and the relative position of the support plate assemblies between the closed housings is locked with set screws.

[0019] During operation, the spherical positioning holes at the bottom of the inner side of the two positioning sleeves respectively provide axial and radial positioning for the electrodes to be ground on both sides. The rectangular part of the structure at the bottom is in a micro-gap fit with the positioning sleeve insertion holes on the left and right rotating covers. The two positioning sleeves rotate synchronously with the left and right rotating covers respectively. The oilless gasket reduces friction during the rotation of the positioning sleeves. After assembly, the stepper motor and its reducer are installed on the outer surface of the right housing by keys and bolts.

[0020] It also includes a set of equipment follow-up swing mechanism, which is fixedly installed on the rear surface of the power motor mounting base and the outer side of the right housing via a connecting plate. The equipment follow-up swing mechanism includes a connecting plate, supports, a sliding working pair consisting of two sets of linear bearings and guide rods, a mounting plate, springs, and bolts. The connecting plate is fixedly installed on the rear outer surface of the power motor mounting base and the right housing. After the two supports are fixedly installed on both sides of the connecting plate, the two guide rods are passed through the corresponding holes on one side of the support from the outside. Then, springs and linear bearings are sequentially installed on the two guide rods respectively. After passing through the corresponding holes on the other side of the support, two retaining rings are used to lock the two sets of parts installed on the two guide rods between the two supports. The mounting plate and the linear bearings are fastened together with bolts.

[0021] It also includes a negative pressure chip suction system, which includes negative pressure channels, a negative pressure generator, and negative pressure pipelines mirror-cut on the inner surfaces of the left and right housings, respectively. The negative pressure channels mirror-cut on the inner surfaces of the left and right housings become tubular channels after the left and right housings are closed. The inner hole of the tubular channel is connected to the negative pressure generator via the negative pressure pipeline, and is connected to the chip discharge conduit via the negative pressure generator. The negative pressure generator is fixedly installed on the equipment bracket. The grinding chips that are immediately sucked out by the negative pressure pass through the negative pressure channels, negative pressure pipelines, and negative pressure generator in the closed housing, and are then led to the chip collection tank designated by the user via the chip discharge conduit.

[0022] The present invention has the following advantages and beneficial effects:

[0023] (1) The multi-edge combination cutting tool grinds the electrode by milling, which requires a smaller electrode grinding pressure. Compared with the known technology of grinding the electrode by scraping with electrode pressure, the tool's service life can be greatly improved because the cutting edge load is drastically reduced.

[0024] (2) The multi-blade combination tool uses the revolution + high-speed rotation method to grind the electrode, and only performs micro-milling grinding on the newly formed layer of the electrode working surface, which can greatly reduce the unnecessary grinding amount in known technologies.

[0025] (3) Since the working surface of the electrode after grinding is flat and the equipment has an automatic compensation function for the grinding angle of the electrode, it can ensure a good instant adhesion effect between the working plane of the electrode and the surface of the workpiece during the spot welding process, improve the power feeding capability of the working surface of the electrode, and create the necessary conditions for improving the quality of the weld and reducing the cost of the spot welding process. Attached Figure Description

[0026] Figure 1 A three-dimensional structural schematic diagram of an automatic grinding device for resistance spot welding electrodes provided in an embodiment of the present invention;

[0027] Figure 2 This is a right-side structural schematic diagram of an automatic grinding device for resistance spot welding electrodes provided in an embodiment of the present invention.

[0028] Figure 3 This is a right-side structural schematic diagram of the automatic grinding device for resistance spot welding electrodes without a support plate assembly, as provided in an embodiment of the present invention.

[0029] Figure 4 for Figure 2 A cross-sectional view of the structure in the AA direction without the swing mechanism;

[0030] Figure 5 for Figure 2 A cross-sectional view of the structure in the BB direction without the swing mechanism;

[0031] Figure 6 for Figure 2 A cross-sectional view of the structure in the CC direction without a swing mechanism;

[0032] Figure 7 This is a schematic diagram of the axial cross-sectional structure of the combined cutting tool provided in an embodiment of the present invention;

[0033] Figure 8 This is a top view of the planar cutting tool provided in an embodiment of the present invention;

[0034] Figure 9 This is a schematic diagram of the axial cross-sectional structure of a planar cutting tool provided in an embodiment of the present invention;

[0035] Figure 10 This is a top view of the arc-shaped cutting tool provided in an embodiment of the present invention;

[0036] Figure 11 for Figure 10 Schematic diagram of the cross-sectional structure along the DD direction;

[0037] Figure 12 This is a top view of the frustum-shaped cutting tool provided in an embodiment of the present invention.

[0038] Figure 13 This is a schematic diagram of the axial cross-sectional structure of the frustum-shaped cutting tool provided in an embodiment of the present invention;

[0039] Figure 14 This is a top view structural diagram of the support plate assembly provided in an embodiment of the present invention;

[0040] Figure 15 This is a schematic diagram of the axial cross-sectional structure of the support plate assembly provided in an embodiment of the present invention;

[0041] Figure 16 This is an enlarged three-dimensional structural diagram of the left shell provided in an embodiment of the present invention;

[0042] Figure 17 This is an enlarged three-dimensional structural diagram of the right shell provided in an embodiment of the present invention;

[0043] Figure 18 An enlarged three-dimensional structural diagram of the left-turn cover in one direction provided in an embodiment of the present invention;

[0044] Figure 19 An enlarged three-dimensional structural diagram of the right-turn cover in one direction provided in an embodiment of the present invention;

[0045] Figure 20 An enlarged three-dimensional structural diagram of the left-turning cover from another direction provided in an embodiment of the present invention;

[0046] Figure 21An enlarged three-dimensional structural diagram of the right-turn cover from another direction provided in an embodiment of the present invention;

[0047] Figure 22 An enlarged three-dimensional structural diagram of the limiting block in one direction provided in an embodiment of the present invention;

[0048] Figure 23 An enlarged three-dimensional structural diagram of the limiting block from another direction provided in an embodiment of the present invention;

[0049] Figure 24 This is an enlarged top view of the ball threaded sleeve provided in an embodiment of the present invention.

[0050] Figure 25 This is an enlarged axial cross-sectional view of the ball threaded sleeve provided in an embodiment of the present invention;

[0051] Figure 26 This is an enlarged front view schematic diagram of the arc-shaped electrode provided in an embodiment of the present invention;

[0052] Figure 27 This is an enlarged front view schematic diagram of the frustum-shaped electrode provided in an embodiment of the present invention.

[0053] The markings in the image are as follows:

[0054] 1-Reversible ball nut, 2-Reversible ball threaded shaft, 3-Setting screw, 4-Left housing;

[0055] 5-Support plate, 6-First bolt, 7-Right housing, 8-Reducer, 9-Stepper motor;

[0056] 10-Motor mounting bracket, 11-Motor, 12-Connecting plate, 13-Linear bearing;

[0057] 14-First support, 15-Spring, 16-Mounting plate, 17-Second bolt, 18-Light bar, 19-Second support;

[0058] 20 - Third bolt, 21 - Limiting block, 22 - Limiting screw, 23 - Fourth bolt, 24 - Fifth bolt;

[0059] 25-Limit plate; 26-Positioning hole; 27-Limit sleeve; 28-Left-turn cover; 29-Rotating gear;

[0060] 30-Flat-faced cutting tool; 31-Curved-faced cutting tool; 32-Sealing plate; 33-Pin; 34-Disc spring;

[0061] 35-Rolling bearing; 36-Needle roller bearing; 37-Oilless gasket; 38-Rotation bearing; 39-Fixed gear ring;

[0062] 40 - Power transition gear bearing; 41 - Power transition gear; 42 - Power input gear;

[0063] 43-Power input gear bearing, 44-Revolution gear, 45-Cutter shaft, 46-Right turn cover;

[0064] 47-tooth guard plate, 48-first screw, 49-second screw, 50-synchronizing gear, 51-third screw;

[0065] 52 - Displacement adjusting gear bearing; 53 - Displacement adjusting gear; 54 - Displacement power transition gear;

[0066] 55 - Displacement power transition gear bearing; 56 - Displacement power input gear bearing;

[0067] 57 - Displacement power input gear; 58 - Frustum-shaped cutting tool; 60 - Negative pressure channel;

[0068] 61-Torsion notch, 62-Arc surface electrode, 63-Frustum-shaped electrode, 641-First plane;

[0069] 642 - Second plane, 651 - First side surface, 652 - Second side surface. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0071] This invention relates to an automatic electrode regrinding device for electrode caps on the electrode grips of the automatic welding gun arms during resistance spot welding. The automatic electrode regrinding device of this invention employs a multi-bladed combination of cutting tools, using a milling method of revolution + high-speed rotation and low electrode pressure to regrind the electrode, resulting in a flat surface at the working end of the regrinded electrode. A positioning and shifting cutting mechanism controls the amount of regrinding per cycle, provides angle compensation for electrode working plane deflection caused by welding gun arm bending deformation, and suppresses axial vibration of the cutting tool during regrinding by pre-setting pressure along the cutting tool's axis. This achieves precise control over the amount of regrinding per cycle, significantly reducing unnecessary cutting amounts, and dynamically compensates for changes in the electrode working plane angle, ensuring good contact between the regrinded electrode working surface and the workpiece surface during spot welding. The working characteristics of the present invention collectively determine the long working life of the cutting tool, the high effective utilization rate of the electrode material, and the good power feeding effect of the refractory electrode surface during the spot welding process. It can achieve significant positive effects in reducing the consumption of cutting tools and electrode materials, reducing the number of electrode replacements, reducing the cost of spot welding process, and improving the quality of weld joints.

[0072] The inventive concept of this automatic grinding device for resistance spot welding electrodes is:

[0073] (1) Establish an electrode grinding method using a multi-edge combination tool with revolution + high-speed rotation and micro-depth positioning milling under small electrode pressure. Change the known grinding method of arc surface of electrode working end face from scraping or scraping and shaping to multi-edge planar milling grinding principle. Overcome the disadvantages of known electrode grinding technology, such as short tool life, excessive proportion of unnecessary electrode grinding amount during each grinding, and low power feeding capacity to welding parts.

[0074] (2) The introduction of the electrode grinding angle dynamic compensation function significantly reduces the negative impact of the increasing change of the electrode working axis angle on the adhesion state between the electrode working plane and the workpiece surface, creating necessary conditions for improving the weld quality and reducing the cost of spot welding process.

[0075] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific embodiments described are only for explanation and illustration of the present invention and are not intended to limit the present invention.

[0076] like Figures 1 to 27As shown in the figure, an automatic grinding device for resistance spot welding electrodes provided in this embodiment of the invention includes a closed shell composed of a left shell 4 and a right shell 7 that are mirror images of each other. The main mechanical structure for achieving the functions of electrode grinding, cutting displacement control, electrode grinding angle compensation, and axial vibration suppression of the cutting tool are all placed inside the closed shell. A device follow-up swing mechanism for balancing the cutting stress on both sides during electrode grinding is fixedly installed on the power motor mounting base 10 and the rear surface of the right shell 7. A negative pressure generator for instantly discharging the chips generated during electrode grinding from the electrode grinding chamber is fixedly installed. Mounted on the equipment bracket; during electrode grinding, the working ends of the electrodes on both sides of the welding clamp, namely the arc-shaped electrode 62 and the frustum-shaped electrode 63, are simultaneously ground by the coordinated operation of the main mechanical structure, the equipment follow-up swing mechanism, and the negative pressure chip suction system; wherein, the power motor 11, the power motor mounting base 10, the stepper motor 9 and its reducer 8 assembly in the mechanism are all fixedly mounted on the outer surface of the right housing 7, and the support plate assemblies in the two sets of cutting displacement control and grinding angle compensation mechanisms are engaged on the positive and negative ball nuts 1 exposed on both sides of the closed housing.

[0077] like Figures 1 to 13 and Figures 16-23 As shown, the electrode grinding device of the present invention includes an electrode grinding mechanism, which includes a grinding power drive device and an electrode grinding device; the grinding power drive device of the electrode grinding mechanism includes a power motor 11, a power motor mounting base 10, a power input gear 42, a power transition gear 41, a power input gear bearing 43, and a power transition gear bearing 40, etc.; the power motor mounting base 10 is fixedly installed on the outer surface of the right housing 7; the outer rings of the two power input gear bearings 43 and the two power transition gear bearings 40 are respectively fitted into the right housing. After the corresponding bearing holes are drilled on the power motor mounting base 10, the left journals of the power input gear 42 and the power transition gear 41 are fitted into the inner rings of the power input gear bearing 43 and the power transition gear bearing 40, which are already placed in the right housing 7, and the power input gear 42 and the power transition gear 41 mesh with each other; after the key (not shown in the figure) is fitted into the keyway drilled on the output shaft end of the power motor 11 and the journal of the power input gear 42, the power motor 11 is fixedly mounted on the outer surface of the power motor mounting base 10 with bolts.

[0078] like Figures 1 to 13 and Figures 16-23As shown, the electrode grinding device of the present invention is responsible for grinding the working ends of the electrodes on both sides of the welding clamp arm handles, namely the working ends of the arc-shaped electrode 62 and the frustum-shaped electrode 63. The electrode grinding device includes a planetary gear 44, a left-turning cover 28, a right-turning cover 46, a limiting block 21, a planetary bearing 38, a combination cutting tool, a fixed gear ring 39, a tooth guard plate 47, a limiting sleeve 27 shared with the support plate assembly, an oil-free gasket 37, and bolts and screws, etc. The outer rings of the two planetary bearings 38 are respectively fitted into the closed shells formed by the left housing 4 and the right housing 7. The two sealing plates 32 are respectively installed in the corresponding recessed platforms on the inner sides of the left housing 4 and the right housing 7, and each is fixed to the left housing 4 and the right housing 7 with four second screws 49 respectively; the outer circle of the fixing gear ring 39 is fitted into the corresponding recessed platform on the inner side of the left housing 4, and the fixing gear ring 39 is fixed in the recessed platform on the inner side of the left housing 4 with four third screws 51; the two limiting blocks 21 are respectively fitted into the recessed platforms on the outer surfaces of the left rotating cover 28 and the right rotating cover 46, and each is fixed with four fourth bolts 23. 21 is fixed between the left-turning cover 28 and the right-turning cover 46 respectively, and a limiting screw 22 is screwed into the threaded hole on the side of each fourth bolt 23; after the inner hole of the revolution gear 44 is tightly fitted into the corresponding countersunk on the outer circle of the right-turning cover 46, the tooth guard plate 47 is fixedly installed in the corresponding countersunk on the outer surface of the revolution gear 44 with four first screws 48; the outer circle of the right-turning cover 46 in the above-mentioned right-turning cover assembly is tightly fitted into the inner circle of the revolution bearing 38 already installed in the right housing 7; the ball bearing at one end of the assembled combined cutting tool is then installed. The bearing 35 is fitted into the corresponding recess on the limiting block 21 from the inside of the right housing 7; the left housing 4 and the right housing 7 are closed, and the following assembly is completed in sequence: First, the left housing 4 and the right housing 7 are fastened together with 6 first bolts 6; Second, the outer circle of the left rotating cover 28 is fitted into the inner hole of the revolution bearing 38 on the left housing 4, and during the process, the recess hole on the inside of the limiting block 21 is fitted with the outer circle of the ball bearing 35 on the other side of the combined cutting tool; Third, the left rotating cover 28 and the right rotating cover 46 are fixedly connected together with 3 third bolts 20.

[0079] like Figures 1-6 , Figure 12 , Figure 13 and Figure 24 and Figure 25As shown, the present invention also includes a cutting displacement control mechanism, which is responsible for the cutting displacement control and electrode grinding angle compensation work during the grinding of the working ends of the electrodes on both sides, namely the first plane 641 of the working end of the arc-shaped electrode 62 or the second plane 642 of the working end of the frustum-shaped electrode 63, and the first side surface 651 on both sides of the working end of the arc-shaped electrode 62 or the second side surface 652 on both sides of the working end of the frustum-shaped electrode 63; the cutting displacement control mechanism includes a set of power drive systems placed inside the closed housing and a cutting displacement control mechanism connecting the inside and outside of the closed housing; the power drive system of the mechanism includes a stepper motor 9 and its reducer 8, a displacement power input gear 57, a displacement power transition gear 54, a synchronous gear 50, a displacement power input gear bearing 56, a displacement transition gear bearing 55, etc.; the cutting displacement control mechanism includes two sets of positive and negative ball thread working pairs composed of two sets of positive and negative ball thread shafts 2 and positive and negative ball thread sleeves 1, a displacement adjustment gear 53, a displacement adjustment gear bearing 52, and two sets of support plate assemblies, etc.; the displacement power input gear bearing 56, the displacement power transition gear bearing 55, etc. Two sets of gear bearings 55 are respectively fitted into the corresponding bearing holes on the left housing 4 and the right housing 7. One side journal of the displacement power input gear 57 and the displacement power transition gear 54 are respectively inserted into the inner rings of the displacement power input gear bearing 56 and the displacement power transition gear bearing 55 located in the right housing 7, thus meshing the two gears, i.e., the displacement power input gear 57 and the displacement power transition gear 54. Four sets of displacement adjusting gear bearings 52 are respectively fitted into the corresponding bearing holes on the left housing 4 and the right housing 7, and are then connected as shown in the figure. After the keyed connection of the two positive and negative ball threaded shafts 2 and the two displacement adjusting gears 53 is not shown, the right journal ends of the two positive and negative ball threaded shafts 2 are inserted into the inner ring of the displacement adjusting gear bearing 52 on the right housing 7; the inner hole of the synchronizing gear 50 is fitted with clearance fit on the outer circle of the fixed gear ring 39, and the synchronizing gear 50 and the displacement adjusting gear 52 are meshed; while closing the left housing 4 and the right housing 7, the displacement power input gear 56, the displacement power transition gear 55 and the left journal of the positive and negative ball threaded shafts 2 are inserted into the corresponding bearing inner rings.

[0080] like Figures 7-13As shown, the combined cutting tool of the present invention includes a rotating gear 29, a flat cutting tool 30, two sets of arc-shaped cutting tools 31 or two sets of frustum-shaped cutting tools 58, a cutting shaft 45, two rolling bearings 35, two disc springs 34, one needle roller bearing 36, and three pins 33, etc.; the outer circle of the flat cutting tool 30 is tightly fitted and symmetrically embedded into the inner hole of the rotating gear 29; the two arc-shaped cutting tools 31, which are respectively left-handed and right-handed, are placed in the grooves on both sides of the flat cutting tool 30, and three pins 33 are fitted into the three corresponding pin holes 33, which are present in all three, to establish a torsional engagement relationship between the three; after the outer circle of the needle roller bearing 36 is fitted into the inner hole of the two arc-shaped cutting tools 31, the cutting shaft 45 is fitted into the inner ring of the needle roller bearing 36; after one disc spring 34 is installed on each side of the above-mentioned combination axially, one rolling bearing 35 is fitted into the outer side of each disc spring. After the combined cutting tool is installed in the closed housing, the axial preload of the curved cutting tool 31 can be adjusted by the screwing depth of the four limiting set screws 22 evenly distributed on the positioning block 21. This is used to restrain the axial vibration that may be generated by the cutting reaction force when the flat cutting tool 30 and the curved cutting tool 31 are grinding the electrode.

[0081] like Figure 8 and Figure 9 As shown, the planar cutting tool 30 has a thin-walled circular ring with symmetrical convex rings on both sides of its outer circumference. A through hole with clearance fit between its center and the outer diameter of the needle roller bearing 36 is axially opened. The surfaces of the convex rings on both sides are parallel planes with forward and reverse rotating cutting edges respectively. In the inner groove of the axial convex ring, three through pin holes 33 are symmetrically opened, corresponding to the positions of the three pin holes 33 opened on the bottom surface of the arc-shaped cutting tool 31. When the arc-shaped electrode 62 or the frustum-shaped electrode 63 is being ground, the rotation plane of the cutting edges on both sides of the planar cutting tool 30 is always in contact with the working end plane of the arc-shaped electrode 62 or the frustum-shaped electrode 63 to be ground on both sides, and only undertakes the milling and grinding of the first plane 641 of the working end of the arc-shaped electrode 62 or the second plane 642 of the working end of the frustum-shaped electrode 63.

[0082] like Figures 10-13As shown, the designation of the arc-shaped cutting tool 31 or the frustum-shaped cutting tool 58 is derived from the outer contour shape of the cutting edge in the axial section of the two cutting tools, namely the arc-shaped cutting tool 31 or the frustum-shaped cutting tool 58. Electrodes used in production mainly include two types: arc-shaped electrodes 62 and frustum-shaped electrodes 63. The selection of the arc-shaped cutting tool 31 or the frustum-shaped cutting tool 58 in the combined cutting tool is determined by the user's requirements for the side shape of the electrode's working end. The arc radius R of the cutting edge of the arc-shaped cutting tool 31 is equal to the arc radius R of the side surface of the arc-shaped electrode 62 to be ground; the specific dimensions are determined by the user's requirements for the surface shape of the electrode after grinding. The cone angle α of the frustum-shaped cutting tool 58 is also determined by the user's requirements for the surface shape of the electrode after grinding. The requirements determine the following: When assembling the combined cutting tools, the spiral direction of the cutting edges of the two curved cutting tools 31 or the frustum-shaped cutting tools 58 must be the same as the spiral direction of the cutting edges of the same side of the flat cutting tool 31 located in the middle of the tool shaft 45; When grinding the electrodes, the cutting edges of the curved cutting tools 31 or the frustum-shaped cutting tools 58 are only milled and ground on the first side surface 651 on both sides of the working end of the curved electrode 62 to be ground or the second side surface 652 on both sides of the working end of the frustum-shaped electrode 63; The axial center of the curved cutting tools 31 or the frustum-shaped cutting tools 58 is provided with an axial through hole 36 that matches the outer diameter of the needle roller bearing 36, and the bottom surface of each of them is provided with three pin holes 33 corresponding to the positions of the three pin holes 33 provided on the bottom surface of the groove of the flat cutting tool 30.

[0083] The planar cutting tool 30, the arc-shaped cutting tool 31, and the frustum-shaped cutting tool 58 are essentially different types of forming milling cutters, and their cutting edge parameters are the same as the corresponding parameters of the same type of milling cutter. The number of cutting teeth n1, n2, or n3 processed on the cutting tool is determined by the diameter of the cutting tool. When the diameter of the arc-shaped electrode 62 or the frustum-shaped electrode 63 increases, the diameter and the number of cutting edges of each cutting tool also increase accordingly.

[0084] like Figure 14 and Figure 15As shown, the cutting displacement control mechanism of the present invention also includes two sets of support plate assemblies; the two sets of support plate assemblies are composed of two identical sets of support plates 5, oil-free gaskets 37, limiting sleeves 27, limiting plates 25, and fifth bolts 24, etc.; the two oil-free gaskets 37 are respectively fitted into the corresponding countersunk holes on the inner side of the two support plates 5, respectively passing through the inner holes of the two oil-free gaskets 37, and each is inserted with a limiting sleeve 27; a limiting plate 25 is fastened to the plane of the support plate 5 on the upper part of the limiting sleeve 27 with two fifth bolts 24. The positive and negative ball nut holes 1 on both sides of the assembled two sets of support plate assemblies are respectively fitted onto the outer diameter of the positive and negative ball nuts 1 in the ball nut screw pairs on both sides of the closed housing, and the relative position of the support plate assembly between the closed housing 4 and 7 is locked with set screws 3. When the equipment is working, the spherical positioning holes 26 on the bottom inner side of the positioning sleeves 27 on both sides respectively undertake the axial and radial positioning of the arc surface electrode 62 or the frustum-shaped electrode 63 to be ground on both sides. The rectangular part of its outer contour is in a micro-gap fit with the positioning sleeve insertion holes 27 on the left turn cover 28 and the right turn cover 46. During operation, the two positioning sleeves 27 rotate synchronously with the left turn cover 28 and the right turn cover 46 respectively. The oilless gasket 37 plays a friction-reducing role during the rotation of the positioning sleeves 27. After the above assembly is completed, the stepper motor 9 and its reducer 8 are installed on the outer surface of the right housing 7 by the key and bolts not shown in the figure.

[0085] like Figures 1-3 As shown, the present invention also includes a set of equipment follow-up swing mechanism, which is fixedly installed on the rear surface of the power motor mounting base 10 and the right housing 7 via a connecting plate 12. The mechanism includes the connecting plate 12, a first support 14 and a second support 19, a sliding working pair consisting of two sets of linear bearings 13 and a guide bar 18, a mounting plate 16, a spring 15, and a second bolt 17. The connecting plate 12 is fixedly installed on the rear outer surface of the power motor mounting base 10 and the right housing 7. Four bolts (not shown in the figure) are used to connect the two... After the first support 14 and the second support 19 are fixedly installed on both sides of the connecting plate 12, the two optical bars 18 are passed through the corresponding holes on one side of the support 14 from the outside. Then, springs 15 and linear bearings 13 are sequentially installed on the two optical bars 18. After passing through the corresponding holes on the other side of the support 19, the two sets of parts installed on the two optical bars 18 are locked between the first support 14 and the second support 19 on both sides using two snap rings not shown in the figure. The mounting plate 16 and the linear bearing 13 are fastened together with the second bolt 17.

[0086] like Figures 16 to 17As shown, the present invention also includes a negative pressure chip suction system, which includes a negative pressure channel 60, a negative pressure generator, and negative pressure pipelines. The negative pressure channel 60 is symmetrically formed on the inner surfaces of the left housing 4 and the right housing 7. After the left housing 4 and the right housing 7 are closed, the inner hole of the negative pressure channel is connected to the negative pressure generator through a negative pressure pipeline (not shown in the figure), and then connected to the chip removal conduit via the negative pressure generator. The negative pressure generator is a commercially available standard part and is fixedly installed on the equipment bracket. The grinding chips that are immediately sucked out by the negative pressure pass through the negative pressure channel 60, the negative pressure pipeline, and the negative pressure generator in the closed housing, and are then led to the chip collection tank designated by the user through the chip removal conduit.

[0087] like Figures 16 to 17 As shown, the axial contours of the left housing 4 and the right housing 7 are mirror images of each other; except for the mounting holes of the power input gear bearing 43 and the power transition gear bearing 40, which only exist on the right housing 7, all other process holes are mirror images of each other in the left housing 4 and the right housing 7.

[0088] like Figures 16 to 17 As shown, due to the independent assembly relationship between the left-turning cover 28 and the revolution gear 46 and the need to add a tooth protection plate 47 to the outside of the revolution gear 43, except for the four bolts not shown in the figure that are added to the right-turning cover 46 for assembling the revolution gear 43 and the right-turning cover 46, and the diameter being slightly smaller than that of the left-turning cover 28, all other process holes and assembly counters are mirror images.

[0089] Figures 26 to 27 The diagram shows a frontal view of two types of standard electrode caps used in production, including arc-shaped electrodes 62 and frustum-shaped electrodes 63. The selection of the arc-shaped cutting tool 31 and the frustum-shaped cutting tool 58 in the automatic electrode sharpening device of the present invention is determined by the shape requirements of the production site for the first side surface 651 on both sides of the working end of the arc-shaped electrode 62 or the second side surface 652 on both sides of the working end of the frustum-shaped electrode 63.

[0090] The working process of the electrode grinding device of the present invention is as follows:

[0091] When the welding clamp, carrying the arc-shaped electrode 62 or the frustum-shaped electrode 63 to be ground, is inserted into the electrode grinding position in the limiting sleeve 27 of the electrode grinding device of the present invention, under the action of electrode grinding pressure, its axial and radial directions are respectively positioned by the first side surface 651 on both sides of the working end of the arc-shaped electrode 62 or the second side surface 652 on both sides of the working end of the frustum-shaped electrode 63 in contact with the positioning hole 26 surface at the bottom of the inner side of the positioning sleeve 27 on both sides of the support plate 5 of the cutting displacement mechanism; after the grinding device receives the command from the robot to position the arc-shaped electrode 62 or the frustum-shaped electrode 63, the power motor 11 of the electrode grinding mechanism is started, and the rotational power is transmitted through the power input gear 42 and the power transition gear 41. The rotation is transmitted to the revolution gear 44; when the revolution gear 44 rotates, the right rotating cover 46 rotates synchronously with the revolution gear 44, and drives the left rotating cover 28 to rotate synchronously through the third bolt 20. It also drives the combined cutting tool placed between the left rotating cover 28 and the right rotating cover 46 to rotate synchronously with the revolution gear 46, which is the revolution of the cutting tool in this invention. Since the self-rotating gear 29 in the combined cutting tool meshes with the fixed gear ring 39 at the same time, the combined cutting tool will rotate at a higher speed with the cutter shaft 45 as the axis according to the tooth ratio between the fixed gear ring 39 and the self-rotating gear 29. This forms the working characteristics of the combined cutting tool in the electrode automatic grinding device of this invention, which is revolution + high-speed self-rotation during the electrode grinding process.

[0092] After the power motor 11 reaches its operating speed, the stepper motor 9 starts. The output shaft of the stepper motor 9 transmits rotational power synchronously to two displacement adjustment gears 53, which are mirror-arranged on both sides of the synchronous gear 50 and mesh with it, through the reducer 8, displacement power input gear 57, displacement power transition gear 54, and synchronous gear 50. The gears then drive the two positive and negative ball thread shafts 2 to rotate synchronously via a key not shown in the figure. During the synchronous rotation of the two positive and negative ball thread shafts 2, the two pairs of ball thread sleeves 1 with opposite threads on both sides of the shaft end can only move in a straight line towards each other at the same speed along the axial direction of the two positive and negative ball thread shafts 2, and drive the support plates on both sides. 5. Simultaneously, the two sides of the arc surface electrode 62 or frustum electrode 63 to be ground gradually come into contact with the cutting edge of the combined cutting tool from both sides along with the positioning sleeves 27 on the two side support plates 5, and the working end of the arc surface electrode 62 or frustum electrode 63 is ground. The speed of the stepper motor 9 determines the axial feed speed of the arc surface electrode 62 or frustum electrode 63 to be ground, that is, the milling speed during the electrode grinding process. When the milling displacement reaches the preset value of the stepper motor 9, it indicates that the grinding amount of the electrode 62 or 63 has met the process requirements, and the stepper motor 9 immediately stops working and waits in place for the next electrode grinding command.

[0093] When the arc-shaped electrode 62 or the frustum-shaped electrode 63 is slowly fed into the grinding process, there is always a dynamically changing inclination angle between the axis of the arc-shaped electrode 62 or the frustum-shaped electrode 63 on both sides and the axis of the electrode positioning hole 26 on the two positioning sleeves 27 of the grinding machine. In most cases, the inclination angles on both sides are not the same, resulting in different cutting stresses when the two sides are grinding electrodes. When different cutting stresses occur on both sides, the follow-up swing mechanism of the equipment will drive the working end of the electrode grinding machine to swing slightly in real time according to the direction of the stress gradient in order to balance the cutting stresses when the two sides are grinding electrodes.

[0094] The electrode grinding angle compensation function is accomplished simultaneously using the cutting displacement control mechanism: when the support plates 5, which are located on both sides of the closed housing, move towards each other along the axial direction of the forward and reverse ball thread shaft 2 to grind the electrode, the tilt angle of the electrode grip will inevitably change. Another compensation function of the electrode grinding angle is to utilize the program controllability of the stepper motor 9 to establish a logical correspondence between the incremental axial displacement of the electrode and the incremental change of the electrode axial tilt angle during the electrode grinding process, thereby achieving the purpose of synchronously compensating for the incremental increase of the electrode grinding angle during the positioning and cutting process.

[0095] The negative pressure generator and the power motor 11 operate under the same control command; the cavity enclosed between the inner surfaces of the left-turning cover 28 and the right-turning cover 46 and the inner surface of the fixed gear ring 39 is the electrode grinding chamber. This chamber is connected to the negative pressure channels 60 respectively opened on the inner side of the left housing 4 and the right housing 7. The chips generated during electrode grinding can be immediately sucked out through the negative pressure channels 60 to the outside of the closed shell formed by the left housing 4 and the right housing 7 of the grinder.

[0096] On the outer end faces of the two sets of positive and negative ball thread sleeves 1, two pairs of torsion notches 61 are radially machined at a certain angle. The purpose of setting the torsion notches 61 is that when it is necessary to slightly change the grinding amount setting of a certain side electrode, the ball nut 1 on the corresponding side can be slightly rotated on the outside of the working end by using a screwdriver-like tool through the notch, so as to facilitate fine adjustment of the grinding amount setting of that side each time.

[0097] After the electrode grinding is completed, the robotic arms on both sides of the welding clamp, according to the robot's control commands, carry the ground arc-shaped electrode 62 or frustum-shaped electrode 63 out of the limiting sleeve 27 of the grinding device from both sides. Simultaneously, the robot sends a signal indicating that the arc-shaped electrode 62 or frustum-shaped electrode 63 has left the grinding device. The power motor 11 and negative pressure generator of the electrode grinding mechanism also stop working and wait for the next electrode grinding command. Thus, the electrode grinding mechanism and the positioning and cutting mechanism work together to complete one complete electrode grinding cycle.

[0098] When installing the electrode grinder of this invention, the mounting plate 16 is used to fix the electrode grinder on the equipment mounting bracket. Because the working height requirements for grinding various types of welding clamps and the posture requirements for grinding arc-shaped electrodes 62 and frustum-shaped electrodes 63 are different on the production site, the equipment mounting bracket needs to be specially configured according to the site requirements. Therefore, the electrode grinder mounting bracket and the negative pressure generator fixed on it are not shown in the accompanying drawings of this invention.

[0099] In summary, this invention utilizes a small electrode pressure condition and a multi-edge combined cutting tool's revolution + high-speed rotation electrode grinding method to grind the working ends of the arc-shaped electrode 62 or the frustum-shaped electrode 63, overcoming various negative attribute problems caused by the cutting tool structure and cutting principle in known technologies. Through the positioning and shifting cutting mechanism, conditions are created for the multi-edge combined cutting tool to perform positioning and shifting cutting grinding of the electrode under micro-depth of cut conditions, not only causing a sharp drop in cutting stress of the cutting tool but also drastically reducing unnecessary grinding amounts in known technologies. The electrode grinding angle compensation device and the stress pre-compression of the combined cutting tool by the disc spring create conditions to ensure the grinding quality of the electrode working plane and provide real-time assurance of the adhesion state between the electrode working surface and the workpiece surface during spot welding operations. The combined implementation of the above-mentioned technical measures has drastically reduced the cutting load on the cutting edge of the tool, greatly improving the tool's service life and the utilization rate of electrode materials. Under the same process conditions, the real-time guarantee of the contact state between the electrode working plane and the workpiece surface during spot welding also provides a basic guarantee for improving electrode power supply efficiency, reducing spot welding process energy consumption, and ensuring weld quality.

[0100] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An automatic grinding device for resistance spot welding electrodes, characterized in that: A closed housing consisting of a left and right shell that are mirror images of each other, with the main mechanical structure for electrode grinding, cutting displacement control, electrode grinding angle compensation, and axial vibration suppression of the cutting tool all housed within the closed housing. A device follow-up swing mechanism to balance the cutting stress on both sides during electrode grinding is fixedly mounted on the motor mounting base and the rear surface of the right shell. A negative pressure generator for instantly removing chips generated during electrode grinding from the electrode grinding chamber is fixedly mounted on the equipment support. During electrode grinding, the coordinated operation of the main mechanical structure, the device follow-up swing mechanism, and the negative pressure chip removal system simultaneously completes the grinding of the electrode working ends on the arm grips on both sides of the welding clamp. The main mechanical structure includes a motor-driven grinding mechanism, wherein: The motor grinding mechanism includes a grinding power drive device and two sets of electrode grinding devices. The two sets of electrode grinding devices are coaxially placed on both sides inside the closed housing. The grinding power drive device includes a power motor, a power motor mounting base, a power input gear, a power transition gear, a power input gear bearing, and a power transition gear bearing. The power motor mounting base is fixedly installed on the outer surface of the right housing. The outer rings of the two power input gear bearings and the two power transition gear bearings are respectively fitted into the corresponding bearing holes on the right housing and the power motor mounting base. The left journals of the power input gear and the power transition gear are fitted into the inner rings of the two bearings already placed in the right housing, and the two gears mesh with each other. After the key is fitted into the keyway on the output shaft end of the power motor and the journal of the power input gear, the power motor is fixedly installed on the outer surface of the power motor mounting base with bolts. The electrode grinding device is used to grind the working ends of the electrodes on both sides respectively. The electrode grinding device includes a left shell, a right shell, a planetary gear, a left rotating cover, a right rotating cover, a limiting block, a planetary bearing, a combination cutting tool, a fixed gear ring, a toothed plate, a limiting sleeve, an oil-free gasket, and bolts and screws. The outer rings of the two planetary bearings are respectively fitted into the corresponding recesses on the outer surfaces of the left and right shells. The two sealing plates are respectively fitted into the corresponding recesses on the inner surfaces of the left and right shells, and each is fixed to the left and right shells with multiple screws. The outer circle of the fixed gear ring is fitted into the corresponding recess on the inner surface of the left shell, and the fixed gear ring is fixed to the recess on the inner surface of the left shell with multiple bolts. The two limiting blocks are respectively fitted into the recesses on the outer surfaces of the left and right rotating covers, and each is fixed to the left and right rotating covers with multiple screws. At the same time, a limiting set screw is screwed into the threaded hole on the side of each screw. After tightly fitting the inner hole of the revolution gear into the corresponding recess on the outer circle of the right turn cover, use multiple screws to fix the tooth guard plate into the corresponding recess on the outer surface of the revolution gear; tightly fit the outer circle of the right turn cover in the right turn cover assembly into the inner circle of the revolution bearing already installed in the right housing; fit the assembled combined cutting tool's shaft end ball bearing into the corresponding recess on the limit block from the inside of the right housing; close the left and right housings, and then complete the following assembly in sequence: fasten the left and right housings together with multiple bolts; fit the outer circle of the left turn cover into the inner hole of the revolution bearing on the left housing, during which the recess hole on the inside of the limit block mates with the outer circle of the shaft end ball bearing on the other side of the combined cutting tool; and fix the left and right turn covers together with multiple bolts.

2. The automatic grinding device for resistance spot welding electrodes according to claim 1, characterized in that, The main body of the mechanical structure also includes a cutting displacement control mechanism, which is responsible for controlling the cutting displacement during the grinding of the working ends of the electrodes on both sides and compensating for the grinding angle of the electrodes. The cutting displacement control mechanism includes a set of power drive systems placed inside the closed housing and a cutting displacement control device that connects the inside and outside of the closed housing. The power drive system includes a stepper motor, a reducer, a displacement power input gear, a displacement power transition gear, a synchronization gear, a displacement power input gear bearing, and a displacement transition gear bearing. The cutting displacement control device includes two sets of positive and negative ball thread working pairs composed of two sets of positive and negative ball thread shafts and positive and negative ball thread sleeves, a displacement adjustment gear, a displacement adjustment gear bearing, and two sets of support plate assemblies.

3. The automatic grinding device for resistance spot welding electrodes according to claim 2, characterized in that, Two sets each of the displacement power input gear bearing and the displacement power transition gear bearing are respectively fitted into the corresponding bearing holes on the left and right housings. The journals on one side of the displacement power input gear and the displacement power transition gear are respectively inserted into the inner rings of the displacement power input gear bearing and the displacement power transition gear bearing located in the right housing, so that the two gears are in a meshing state.

4. The automatic grinding device for resistance spot welding electrodes according to claim 3, characterized in that, Four sets of displacement adjusting gear bearings are respectively fitted into the corresponding bearing holes on the left and right housings. After keying the two positive and negative ball thread shafts with the two displacement adjusting gears, the right journal ends of the two positive and negative ball thread shafts are fitted into the inner ring of the displacement adjusting gear bearing on the right housing. The inner hole of the synchronizing gear is fitted onto the outer circle of the fixed gear ring with clearance fit, and the synchronizing gear meshes with the displacement adjusting gear. At the same time as closing the left and right housings, the displacement power input gear, displacement power transition gear, and the left journal of the positive and negative ball thread shaft are fitted into the corresponding bearing inner ring.

5. The automatic grinding device for resistance spot welding electrodes according to claim 1, characterized in that, It also includes a set of combined cutting tools, which comprises a rotating gear, a flat cutting tool, two sets of arc-shaped cutting tools or two sets of frustum-shaped cutting tools, a cutting shaft, two rolling bearings, two disc springs, a needle roller bearing, and pins; the outer circle of the flat cutting tool is tightly fitted and axially symmetrically embedded into the inner hole of the rotating gear; two arc-shaped cutting tools, one helical and one reciprocal, are placed in grooves on both sides of the flat cutting tool, and three pins are inserted into the three corresponding pin holes present in all three tools to establish a torsional engagement relationship between them; the outer circle of the needle roller bearing is... After the round fitting is inserted into the inner hole of the two arc-shaped cutting tools, the cutter shaft is fitted into the inner ring of the needle roller bearing; after installing one disc spring on each side of the axial direction of the cutter shaft, one rolling bearing is fitted into each outside the disc spring; after the combined cutting tool is installed into the closed housing, the axial preload of the disc springs on both sides of the arc-shaped cutting tool is adjusted by the screwing depth of the four limiting set screws evenly distributed on the positioning block, in order to restrain the axial vibration that may be generated by the cutting reaction force when the flat cutting tool and the arc-shaped cutting tool are grinding the electrode.

6. The automatic grinding device for resistance spot welding electrodes according to claim 5, characterized in that, The planar cutting tool has a thin-walled circular ring with symmetrical convex rings on both sides of its outer circumference. A through hole with clearance fit between the center and the outer diameter of the needle roller bearing is formed. The surfaces of the two convex rings on both sides are parallel planes with forward and reverse rotating cutting edges respectively. Three through pin holes are symmetrically formed in the grooves on the inner side of the axial convex rings, corresponding to the positions of the three pin holes formed on the bottom surface of the arc-shaped cutting tool. When grinding the electrodes, the rotating plane of the cutting edges on both sides of the planar cutting tool is always in contact with the working end plane of the electrodes to be ground on both sides, and only undertakes the milling and grinding of the working end plane of the electrodes on both sides.

7. The automatic grinding device for resistance spot welding electrodes according to claim 4, characterized in that, The cutting displacement control mechanism also includes two sets of support plate assemblies. Each set of support plate assemblies consists of a support plate, an oil-free gasket, a limiting sleeve, a limiting plate, and bolts. The two oil-free gaskets are respectively fitted into the corresponding countersunk holes on the inner side of the two support plates, passing through the inner holes of the two oil-free gaskets, and a limiting sleeve is inserted into each. A limiting plate is fastened to the upper part of each limiting sleeve with two bolts. The positive and negative ball nut holes on both sides of the assembled two sets of support plate assemblies are respectively fitted onto the outer diameter of the positive and negative ball nuts in the ball nut screw pairs on both sides of the closed housing, and the relative position of the support plate assemblies between the closed housings is locked with set screws.

8. The automatic grinding device for resistance spot welding electrodes according to claim 7, characterized in that, During operation, the spherical positioning holes at the bottom of the inner side of the two positioning sleeves respectively provide axial and radial positioning for the electrodes to be ground on both sides. The rectangular part of the structure at the bottom is in a micro-gap fit with the positioning sleeve insertion holes on the left and right rotating covers. The two positioning sleeves rotate synchronously with the left and right rotating covers respectively. The oilless gasket reduces friction during the rotation of the positioning sleeves. After assembly, the stepper motor and its reducer are installed on the outer surface of the right housing by keys and bolts.

9. The automatic grinding device for resistance spot welding electrodes according to claim 1, characterized in that, It also includes a set of equipment follow-up swing mechanism, which is fixedly installed on the rear surface of the power motor mounting base and the outer side of the right housing via a connecting plate. The equipment follow-up swing mechanism includes a connecting plate, supports, a sliding working pair consisting of two sets of linear bearings and guide rods, a mounting plate, springs, and bolts. The connecting plate is fixedly installed on the rear outer surface of the power motor mounting base and the right housing. After the two supports are fixedly installed on both sides of the connecting plate, the two guide rods are passed through the corresponding holes on one side of the support from the outside. Then, springs and linear bearings are sequentially installed on the two guide rods respectively. After passing through the corresponding holes on the other side of the support, two retaining rings are used to lock the two sets of parts installed on the two guide rods between the two supports. The mounting plate and the linear bearings are fastened together with bolts.

10. The automatic grinding device for resistance spot welding electrodes according to claim 1, characterized in that, It also includes a negative pressure dust collection system, which includes negative pressure channels, a negative pressure generator, and negative pressure pipelines mirror-cut on the inner surfaces of the left and right housings, respectively. Negative pressure channels are symmetrically mirrored on the inner surfaces of the left and right housings, forming a tubular channel after the left and right housings are closed. The inner hole of the tubular channel is connected to a negative pressure generator via a negative pressure pipeline, and then connected to a chip removal conduit via the negative pressure generator. The negative pressure generator is fixedly mounted on the equipment bracket. The grinding chips that are immediately sucked out by the negative pressure pass through the negative pressure channel, negative pressure pipeline, and negative pressure generator in the closed housing, and are then led to the chip collection tank designated by the user via the chip removal conduit.

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