WO2013163874A1

WO2013163874A1 - Protection device for spot-welding electrode with automatic feeding mechanism

Info

Publication number: WO2013163874A1
Application number: PCT/CN2012/085616
Authority: WO
Inventors: 罗震; 敖三三; 孟繁亮; 任吉刚; 李丰
Original assignee: 天津大学
Priority date: 2012-05-04
Filing date: 2012-11-30
Publication date: 2013-11-07
Also published as: CN102672335A; CN102672335B

Abstract

A protection device for a spot-welding electrode with an automatic feeding mechanism comprises two groups of identical protection units respectively fixed on an upper electrode and a lower electrode. The protection unit comprises a movable bracket (101) which is fixedly connected with the electrode (130) and can move up and down along a bracket body (103). The lower part of the bracket body is a portal frame (105); an inner bracket (113) capable of moving up and down is provided inside the portal bracket and a pedestal (114) coated with an insulation coating is equipped at the bottom of the portal bracket. In the inner bracket is provided with a horizontal shaft (116) which is fixedly connected with a pair of gears (107); the pair of gears are upwardly linked with a ratchet -and-pawl mechanism. The pawl (104) in the ratchet-and-pawl mechanism is connected with the bracket body through a tension spring (111); the two gears drive a metal sheet (120) to move; the metal sheet is extracted from a feeding box (140). The front and the rear section in the direction of the movement are respectively provided with an upward and downward flexing folded plate whose angles are coincided; and a rack engaging with the pair of gears is respectively provided at the two sides of the metal sheet. The spot-welding electrode protection device of the spot-welding electrode can realize the automatic feed, improve the service life of the electrode and protect the electrode.

Description

Spot welding electrode protection device with automatic feeding mechanism

The present invention relates to a device for improving the life of a spot welding electrode, and more particularly to a spot welding electrode protection device. Background technique

At present, in the modern aviation, automobile and home appliance industries, the application of galvanized steel sheets and aluminum alloy sheets with better rust prevention ability and high service life is increasing. Due to the large number of thin plate structures, spot welding is generally used for welding to obtain good weld quality.

In the spot welding process, the main function of the spot welding electrode is to transmit current, pressurize and dissipate heat. The welding current during spot welding can be as high as several thousand to several tens of thousands of amps, the electrode pressure can reach several hundred megapascals, and the electrode head diameter will be It increases with the increase of electrode use time, which leads to a decrease in current density during spot welding, which leads to a decrease in the diameter of the formed solder joints and a decrease in strength. For example, in the automotive industry where resistance spot welding is used in a large amount, in general, the automobile body needs to be welded 5000. -6000 points, but the existing spot welding electrodes can only weld about 500 points at a time. Frequent refurbishment and replacement of electrodes reduces production efficiency and increases production costs. Therefore, electrode life is an important measure of spot weld quality and weldability. index. Therefore, research on extending the life of the electrode is urgently needed.

People mainly improve the life of spot welding electrodes from the following three aspects. The first is to study the new spot welding electrode materials; the second is to select welding materials with good weldability; the third is to improve the spot welding process and equipment. At present, the research on the electrodes is started from the electrode itself, which is to improve the life of the electrode material itself, and does not fundamentally solve the problem of electrode loss.

A resistance spot welding electrode life extension device is disclosed in Chinese Patent Publication No. CN101081456, the disclosure of which is hereby incorporated by reference. The device comprises an upper moving bracket 6, an upper bracket 5, and an active connection between the upper moving bracket 6 and the upper bracket 5; a lower bracket 16 and a lower moving bracket 12, which are also movably connected; an upper spindle 3 and a lower spindle 18, Springs respectively mounted between the upper and lower spindles 3, 18 and the upper and lower brackets 5, 16; curved upper flywheel 9 and lower flywheel 19; upper ratchet mechanism 1 and lower ratchet mechanism 13; respectively located on the upper and lower flywheels 9 , copper plate on 19; upper link mechanism and lower link mechanism; upper hook mechanism and lower hook mechanism. The above-mentioned resistance spot welding electrode life extension device has a complicated structure, a large volume, and the detail design is not reasonable. For example, the step counting device is inaccurate, thereby making it impossible to install it into the corresponding device.

In addition, in the prior art, the problem of continuously feeding the device cannot be solved. Feeding in the prior art generally requires the worker to replace the metal sheet during the spot welding process, which often results in an unnecessary increase in working time, thereby increasing the cost. Also, due to individual differences in workers and different levels of operation, problems can result in unreasonable clamping. The function of the device cannot be achieved smoothly. Summary of the invention

In view of the above prior art, the present invention provides a spot welding electrode protection device having an automatic feeding mechanism, which can reduce electrode alloying, abrasion, pitting and thermal fatigue, etc., and improve electrode life, thereby achieving the purpose of protecting the electrode.

In order to solve the above technical problem, the technical solution of the spot welding electrode protection device with the automatic feeding mechanism is: The spot welding electrode protection device with the automatic feeding mechanism is composed of two sets of the same structure and respectively fixing the upper and lower electrodes. The protection unit includes a bracket body, and one end of the bracket body is provided with a moving bracket fixedly connected to the electrode and movable up and down; the lower part of the bracket body is a "door" frame, and the "door" An inner bracket movable up and down is disposed in the frame, a bottom is disposed on a bottom of the "door" frame, and a bottom surface of the base is coated with an insulating coating; a horizontal axis is disposed in the inner bracket, and the horizontal axis is The upper fixed body has a pair of gears, and has a replaceable metal piece, both sides of which are racks that cooperate with the pair of gears; the pair of gears are provided with a ratchet pawl mechanism, and the ratchet pawl mechanism The pawl is connected to the bracket body by a tension spring, and the pulling force of the tension spring causes the pawl to momentarily press on the teeth of the ratchet; the ratchet pawl mechanism drives the two gears to rotate. The two gears move the metal sheet; the front and rear sections of the metal plate are respectively provided with bent plates which are bent upward and downward, and the angles of the front and rear bent plates are matched; the spindle is fixed a feeding box, a bottom of the side wall of the feeding box is provided with a feeding opening, the width of the feeding opening corresponds to the width of the metal piece, and the height of the feeding opening is consistent with the working height of the metal piece, when the pair When the gear moves the metal piece, due to the action of the bent plates at the front and rear ends of the metal piece, a piece of metal piece on the front side moves the metal piece behind, so that the metal piece is sequentially pulled out from the feeding box.

The spot welding electrode protection device of the present invention has an automatic feeding mechanism, wherein the upper side of the bracket body is a fork structure, and the moving bracket is provided with a through hole for inserting into the bracket body, the moving The up and down movement of the bracket is realized by a main shaft disposed in the middle of the upper portion of the bracket body, a pressure spring disposed on the main shaft, and a limiting structure disposed on the main shaft; the moving bracket is provided with a fixing electrode Clamping structure.

The present invention has a spot welding electrode protection device with an automatic feeding mechanism, wherein the ratchet pawl mechanism comprises a ratchet set having a three-stage adjustment function, the ratchet set comprising three ratchets and three spines respectively corresponding to three ratchets The claws, the two-stage ratchets in the ratchet set are set as the adjustable second-stage ratchets, thereby forming different combinations, so that the number of points of the electrodes at the same position of the metal piece can be arbitrarily adjusted during the spot welding process. The ratchet set with three-stage adjustment function uses a three-stage ratchet, the number of primary ratchet teeth is 10, including one tooth with deeper teeth; the second ratchet The number of teeth is 8 or 10, including two symmetrically distributed teeth with deeper teeth; the number of teeth of the third-stage ratchet is 10; when the first-stage pawl extends into the tooth with deeper teeth on the primary ratchet, At the same time, the secondary pawl is in contact with the secondary ratchet, and the secondary ratchet is rotated; when the secondary pawl extends into the deeper tooth on the secondary ratchet, the third-stage pawl is only three The level ratchet contact toggles the three-stage ratchet rotation. Since the three-stage ratchet is fixedly connected with the pair of gears, the three-stage ratchet drives a pair of gears to rotate synchronously, thereby driving the metal piece to move by one step. 5毫米。 The metal sheet is a copper sheet, the thickness of the copper sheet is 0. 5-1. 2 mm.

Compared with the prior art, the beneficial effects of the present invention are:

In the spot welding electrode protection device having the automatic feeding mechanism of the present invention, a metal piece is placed between the electrode and the workpiece, and the loss of the electrode is replaced by the consumption of the metal piece. Experiments have shown that the electrode head has scratches caused by a little physical friction on the copper sheet and a little aluminum is adhered to the electrode when the copper sheet is welded through in the final stage of the experiment, and the electrode is hardly damaged, especially using copper. The welding quality is relatively good and does not react with the electrode. Therefore, the electrode can be almost completely free from loss and the electrode is zero-depleted, thereby solving the technical problem of protecting the electrode. The device of the invention has a simple structure, a small volume and is easy to implement. In addition, in view of the feeding problem existing in the prior art, an automatic feeding device is provided, which enables the spot welding process to be continued without manual refueling, thereby reducing the operation difficulty, reducing the process time, and further reducing the working cost. DRAWINGS

Figure 1-1 is a schematic view showing the assembly of an electrode life extension device and an upper electrode in the prior art; Figure 1-2 is a schematic view showing the assembly of the device and the upper electrode as seen from the rear of Figure 1-1;

Figure 1-3 is a schematic view showing the assembly of the device shown in Figure 1-1 and the lower electrode;

Figure 2-1 is a front cross-sectional view showing a protection unit of the spot welding electrode protection device with an automatic feeding mechanism of the present invention;

Figure 2-2 is a plan view of the protection unit shown in Figure 1-1;

Figure 2-3 is a left side view of the protection unit shown in Figure 1-1;

Figure 2-4 is a right side view of the protection unit shown in Figure 1-1 when the moving bracket is at a low point;

2-5 is a schematic view showing the assembly of the protection unit, the upper electrode, the metal piece and the feeding box shown in FIG. 1-1; FIG. 3-1 is a schematic view showing the outline of the first stage ratchet in the ratchet group of the present invention;

3-2 is a schematic view showing the outline of a secondary ratchet in the ratchet set of the present invention;

3-3 is a schematic view showing the outline of another secondary ratchet in the ratchet set of the present invention;

3-4 are schematic views of the outline of a three-stage ratchet in the ratchet set of the present invention. Description of the main reference symbols in the figure:

101—Moving bracket 102--Pressure spring 103——Standing body

104 - pawl 105 - - frame 106 - anti-falling pawl

107 - a pair of gears 108 - - spring piece 109 - spindle

191——Limited structure 110--Clamp ring 111-tension spring

112——tightening bolt 114- - base 141——first level ratchet

142——Secondary ratchet 143- -Three-stage ratchet 120——Metal sheet

130——Upper and lower electrodes 140--Feeding box

The invention is described in further detail below with reference to the drawings and specific embodiments.

The spot welding electrode protection device with the automatic feeding mechanism of the invention is composed of two sets of protection units having the same structure and respectively fixing the upper and lower electrodes. The following is a detailed description of one of the protection units.

As shown in FIG. 2-3 and FIG. 2-4, the protection unit includes a bracket body 103. The bracket body 103 is provided with a fork structure. One end of the bracket body 103 is fixedly connected to the electrode 130. The movable bracket 101 can be moved up and down; the lower portion of the bracket body 103 is a "door" frame 105, and the "door" frame 105 is provided with an inner bracket 113 movable up and down, and the "door" frame 105 is provided. The bottom of the base 114 is provided with an insulating coating; the inner bracket 113 is provided with a horizontal axis 116. As shown in FIG. 2-1, the moving bracket 101 is provided with a through hole. Inserted onto the bracket body 103, the up and down movement of the moving bracket 101 is through a main shaft 109 disposed in the upper middle portion of the bracket body 103, and a compression spring 102 fitted on the main shaft 109 and disposed on the main shaft The limit structure 119 on the 109 defines the limit position on the moving bracket 101. As shown in FIG. 2-1 and FIG. 2-2, the moving bracket 101 is provided with a device for fixing the electrode 103. Clip structure, the clamping structure includes a shift Clamping collar with an opening on the stand 101 for fastening the fastening bolt 10 and the clamp ring member 112.

As shown in FIGS. 2-4, a horizontal axis is disposed in the "door" frame 103 at the lower portion of the bracket body 103.

I. The thickness of the copper sheet is 0.5. The thickness of the copper sheet is 0.5. -1. 2 mm. A rack having a tooth shape conforming to the gear tooth shape is provided on both sides of the length of the metal piece 120, and both ends of the metal piece 120 in the moving direction are respectively bent at an angle of 45 degrees upward and downward, that is, The front end of the metal plate 120 in the moving direction is provided with an upwardly bent plate, and a rearward bent plate is provided at a rear end in the moving direction of the metal plate 120; the metal piece 120 is stored in the feeding box In 140, the feeding box is a metal box fixed on the main shaft 109. The bottom of the side wall of the feeding box 140 is provided with a feeding port, and the width of the feeding port corresponds to the width of the metal piece, because the front and rear ends of each piece of metal piece 120 There are respectively bent plates that are upward and downward, and the angles are matched. Therefore, during the operation of the spot welding electrode protection device with the automatic feeding mechanism, when a metal piece 120 is sent out, the front piece of the bent plate is just hooked. When the pair of gears 107 drive the metal piece 120 to move, the metal piece 120 can be pulled out from the feeding box in sequence. In order to prevent the gear from being reversed, the anti-falling pawl 106 and the elastic piece 108 are disposed. 2-1; in order to control the moving characteristics of the metal piece 120, a ratchet pawl mechanism is provided on the outer side of one of the gears, and the pawl 104 in the ratchet pawl mechanism passes through the tension spring 111 and the bracket body 103. The tension of the tension spring 111 causes the pawl to momentarily press against the teeth of the ratchet wheel 141; the ratchet pawl mechanism drives the pair of gears 107 to rotate, and the pair of gears further drive the metal piece 120 to move. The ratchet pawl mechanism includes a ratchet set having a three-stage adjustment function, the ratchet set includes three ratchets 141, 142, 143 and three pawls respectively corresponding to the three ratchets, and the ratchet set is set to have By changing the secondary ratchets to form different combinations, it is possible to arbitrarily adjust the number of dots of the electrodes at the same position of the metal piece during the spot welding process.

The ratchet set with three-stage adjustment function uses a three-stage ratchet. As shown in Figure 3-1, Figure 3-2, Figure 3-3 and Figure 3-4, the primary ratchet 141 has a number of teeth of 10, including a deep tooth profile. The number of teeth of the secondary ratchet 142 is 8 (Fig. 3-2) or 10 (Fig. 3-3), including two symmetrically distributed teeth with deeper teeth; the number of teeth of the third stage ratchet 143 is 10. When the first-stage pawl protrudes into the tooth with deeper teeth on the first-stage ratchet 141, at the same time, the second-stage pawl comes into contact with the second-stage ratchet 142, and the second-stage ratchet 142 is rotated; When the claw protrudes into the tooth with deep tooth shape on the second ratchet 142, the third-stage pawl contacts the third-stage ratchet 143 to rotate the three-stage ratchet 143, because the three-stage ratchet 143 and the pair of gears 107 The three-stage ratchet 143 drives the pair of gears 107 to rotate synchronously, thereby driving the metal piece 120 to move by one step. When the metal piece 120 moves, the movement of the next metal piece is driven by the action of the bent plates at the front and rear ends of the metal piece.

The movement process of the protection unit in the spot welding electrode protection device with the automatic feeding mechanism of the invention is: arranging the two protection units symmetrically up and down, and fixing the upper and lower electrodes respectively and clamping them in the respective clamping ring 110, and ensuring The central axes of the upper and lower electrodes coincide and the center lines of the spindles of the two protection units coincide, and metal sheets are inserted into the two protection units, respectively.

First, referring to FIG. 2-4 and FIG. 2-5, and the above electrode movement is taken as an example for description: When the upper electrode 130 moves downward, the moving bracket 101 is moved downward, and the pressure spring 102 on the main shaft 109 is compressed. The state, and pushes the inner bracket 113 downward. The inner bracket 113 drives the ratchet assembly thereon to move downward, forcing the primary pawl to be removed from the original randomly inserted gear teeth. When the downward movement of the spindle 109 is stopped (ie when the bottom of the inner bracket is bottom and bottom) When the seat 114 is in contact, at this time, the first stage pawl just moves into the gap of the next gear of the first stage ratchet, and when the electrode is recovered after the point is finished, the upper spindle 109 is moved upward by the elastic force of the pressure spring 102, The ratchet mechanism also moves upward, and the first stage pawl is just caught in the next tooth gap of the primary ratchet 141, so the primary pawl will push the first ratchet 141 to rotate the angle corresponding to one tooth in the circumferential direction. Both the inner bracket and the ratchet set return to their original height.

Similarly, the lower electrode portion is similar to the upper electrode portion during movement, except that the lower electrode is not moved at this time, and the lower spindle is moved downwardly and backwardly, and the downward force is brought by the downward movement of the upper electrode. When the upper electrode is in contact with the metal piece in the upper protection unit, the base of the upper protection unit contacts the workpiece and continues to push the workpiece downward; the support body of the lower protection unit forces the lower spindle to move downward. , in turn, the ratchet pawl mechanism in the lower protection unit is moved, and the movement of the moving bracket in the upper protection unit is the same as the upward movement. The movement of the ratchet pawl mechanism during the movement is the same as in the upper protection unit and will not be described again.

In the above ratchet pawl mechanism, it has been clarified that several different points can be played. Here, taking 50 points as an example, as shown in Fig. 3-1, Fig. 3-3, Fig. 3-4, the ratchet set is composed of three stages of ratchets. Composition,

Both the primary and secondary ratchets have deeper teeth. Only when the longer claws of the primary pawl encounter deep teeth, the shorter of the secondary pawls can reach the secondary ratchet wheel. In the teeth, and drive the secondary ratchet to move circumferentially, and when the shorter claw of the secondary pawl reaches into the deeper interdental gap of the secondary ratchet, the shortest three-staged pawl can reach the third-stage ratchet wheel. In the tooth, the pair of gears 107 are driven to rotate, that is to say, different first-stage ratchets in the ratchet group cooperate with the second-stage ratchet and the three-stage ratchet to change different number of hits.

When the first-stage ratchet and the second-stage ratchet shown in Figure 3-1 and Figure 3-3 are combined with the three-stage ratchet shown in Figure 3-4, when the primary ratchet rotates once, the secondary ratchet rotates one tooth. When the secondary ratchet rotates 5 times, the three-stage ratchet can rotate one tooth. Therefore, when the electrode is struck, the metal piece that is engaged with the pair of gears 107 every 50 points of the electrode moves a small distance; The ratchet group consisting of three ratchets shown in Fig. 3-1, Fig. 3-2 and Fig. 3-4, when the 0-stage ratchet rotates once, drives the second ratchet to rotate one tooth, and when the second ratchet rotates by 4, Only then can the three-stage ratchet rotate one tooth. Therefore, when the electrode is struck, it is reflected that the electrode is moved 40 points, and the metal piece engaged with the pair of gears is moved by a small distance.

Although the present invention has been described in connection with the drawings, the present invention is not limited to the specific embodiments described above, and the specific embodiments described above are merely illustrative and not restrictive, and those of ordinary skill in the art Many variations are possible without departing from the spirit of the invention, and these are within the protection of the invention.

Claims

Rights request

1. A spot welding electrode protection device having an automatic feeding mechanism, comprising two sets of protection units having the same structure and respectively fixing upper and lower electrodes;

The protection unit includes a bracket body (103), and one end of the bracket body (103) is provided with a movable bracket (101) fixedly connected to the electrode (130) and movable up and down;

The lower part of the bracket body (103) is a "door" frame (105), and the "door" frame (105) is provided with an inner bracket (113) movable up and down, the "door" frame ( The base of the base is provided with a base (114), the bottom surface of the base (114) is coated with an insulating coating; the inner bracket (113) is provided with a horizontal axis (116), and the horizontal axis (116) is fixed There is a pair of gears (107) connected with a replaceable metal piece (120) on both sides of the rack that cooperates with the pair of gears (107); the pair of gears (107) are provided with ratchet spines a pawl mechanism, the pawl (104) in the ratchet pawl mechanism is coupled to the bracket body (103) by a tension spring (111), and the pulling force of the tension spring (111) causes the pawl to momentarily press on the teeth of the ratchet wheel The ratchet pawl mechanism drives the two gears to rotate, and the two gears move the metal piece (120) to move;

The front and rear sections of the metal plate (120) are respectively provided with bent plates which are bent upward and downward, and the angles of the bent plates at the front and rear ends are matched; a feeding box is fixed on the main shaft (109). (140), a bottom of the side wall of the feeding box (140) is provided with a feeding opening, the width of the feeding opening corresponds to the width of the metal piece, the height of the feeding opening and the working height of the metal piece (120) Consistently, when the pair of gears (107) drive the metal piece (120) to move, due to the action of the bent plates at the front and rear ends of the metal piece, a piece of metal piece on the front side moves the metal piece behind, so that the metal piece (120) is fed from the material. The box (140) is pulled out in order.

The spot welding electrode protection device with an automatic feeding mechanism according to claim 1, wherein the bracket body (103) has a fork structure above, and the moving bracket (101) is provided a through hole, which is inserted into the bracket body (103), and the moving bracket (101) is moved up and down by being disposed in the bracket body

(103) an upper middle main shaft (109) and a pressure spring (102) fitted to the main shaft (109) and a limit structure provided on the main shaft (109); the moving bracket (101) ) A clamping structure for fixing the electrodes is provided.

3 . The spot welding electrode protection device with an automatic feeding mechanism according to claim 1 , wherein the ratchet pawl mechanism comprises a ratchet set having a three-stage adjustment function, and the ratchet set includes three ratchet wheels. And three pawls corresponding to the three ratchets respectively, and the second ratchet in the ratchet set is set as the adjustable secondary ratchet. Thereby forming different combinations, it is possible to arbitrarily adjust the number of dots of the electrode at the same position of the metal piece during the spot welding process.

The spot welding electrode protection device with an automatic feeding mechanism according to claim 3, wherein the ratchet group having the three-stage adjustment function adopts a three-stage ratchet, wherein the first-stage ratchet (141) has a number of teeth of 10 , including a tooth with deeper teeth; the number of teeth of the second ratchet (142) is 8 or 10, including two symmetrically distributed teeth with deeper teeth; the number of teeth of the third-stage ratchet (143) is 10; The first-stage pawl extends into the tooth with deeper teeth on the first-stage ratchet (141), and at the same time, the second-stage pawl comes into contact with the second-stage ratchet (142), and the second-stage ratchet (142) is rotated; When the secondary pawl protrudes into the tooth with deeper teeth on the secondary ratchet (142), the third-stage pawl contacts the third-stage ratchet (143) and the three-stage ratchet (143) rotates, due to the third-stage The ratchet wheel (143) is fixedly connected with the pair of gears (107), and the three-stage ratchet wheel (143) drives a pair of gears (107) to rotate synchronously, thereby driving the metal piece (120) to move by one step.

5-1. 2。 The thickness of the copper sheet is 0. 5-1. 2 Millimeter.