Automatic wire feeding system for automobile frame welding robot

Abstract

The application discloses an automatic wire feeding system for a car frame welding robot and belongs to the field of welding robot equipment. The automatic wire feeding system comprises a mounting seat plate mounted on a mechanical arm of the welding robot, a wire feeding driving mechanism mounted on one side of the mounting seat plate, a welding wire reel mounted on the wire feeding driving mechanism and a gas feeding and wire feeding mechanism mounted on the other side of the mounting seat plate, and a stroke detection mechanism is arranged in the control adjusting mechanism. A supporting fixed rod is arranged on the mounting seat plate and located on one side of the connecting rod, a wire feeding mechanism is mounted on the supporting fixed rod, and a control mechanism is arranged on the front part of the mounting seat plate. When the welding wire is changed in diameter, the wire feeding mechanism can effectively and stably press and hold the welding wire to rotate and feed into the wire feeding pipe, so that the situation that the welding wire instantaneously appears 'fast emergence' or'slow emergence' is avoided, and the situation that the melted welding wire blocks the conductive nozzle is reduced under the stable welding program control.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of welding robot equipment, and particularly relates to an automatic wire feeding system for a car frame welding robot. BACKGROUND

[0002] Nowadays, with the large-scale production of cars, welding robots with intelligent manipulators have stronger stability and durability, and the car frames welded by manual welding are also replaced by a large number of welding robots.

[0003] At present, welding robots loaded with CO2 gas shielded welding are widely used in the welding of carbon steel plate frames with a thickness of 2-4 mm due to low cost and high efficiency, and the welds are rust-resistant and easy to operate, which is suitable for large-scale production.

[0004] The welding torch is installed on the multi-axis arm of the welding robot, and the welding torch is connected to the wire feeding pipe, and the wire feeding pipe is connected to the tee joint of the wire feeder installed on the base of the welding robot, and the tee joint is connected to the gas valve and the flow valve connected to the carbon dioxide compressed gas tank. The welding wire on the welding wire reel is released by the wire release driving mechanism in the wire feeder, and the welding wire is leveled by the leveling wheel, and the leveled welding wire is continuously fed to the wire feeding pipe through the tee joint. After the positive electrode of the conducting nozzle in the welding torch is connected to the external control system in the welding robot, the electric signal for feeding the wire and gas is sent to the integrated controller on the wire feeder, and the gas valve is opened and controlled by the integrated controller. The wire release driving mechanism and the wire feeding mechanism are controlled to operate, so that when the welding torch held by the multi-axis arm of the welding robot is aligned with the welding area, the carbon dioxide protective gas is quickly sprayed out, and the welding wire is discharged when the welding wire is continuously melted and consumed. When the welding torch held by the multi-axis arm of the welding robot leaves the welding area, the spraying of carbon dioxide protective gas is immediately stopped, and the supply of welding wire is stopped.

[0005] However, the carbon steel welding wire commonly used on the market is mostly processed by suppliers by melting raw materials into billets, then processed into shaped products by hot pressing and cold drawing, and finally processed by copper or zinc plating surface treatment. Due to the large amount of processing, although the tolerance design is carried out under the hot pressing and cold drawing treatment, the welding wire will not appear to be larger in diameter, but the cross-sectional diameter of the part of the welding wire will be smaller than that of other parts due to the unevenness of the cold drawing and surface treatment section, that is, the welding wire will be changed in diameter, so that after entering the wire feeding mechanism, the two wire feeding wheels driven by rotation will be difficult to effectively contact the welding wire in this area. Under the action of the wire release driving mechanism and the wire feeding pipe on the welding wire, the welding wire discharged through the welding torch outlet will appear "fast" or "slow" at the moment, and the melted welding wire will easily block the conducting nozzle during the welding process, and the machine will have to be stopped for repair.

[0006] In order to reduce the occurrence of this situation, it is necessary to set up an automatic wire feeding system for automobile frame welding robot which can effectively feed wire to the wire reducing area. SUMMARY

[0007] The automobile frame welding robot automatic wire feeding system of the present application is provided to solve the problems in the prior art.

[0008] To achieve the above object, the present application provides the following technical solutions: an automobile frame welding robot automatic wire feeding system, comprising a mounting seat plate mounted on a welding robot mechanical arm, a wire feeding driving mechanism mounted on one side of the mounting seat plate, a welding wire reel mounted on the wire feeding driving mechanism, and a gas feeding and wire feeding mechanism mounted on the other side of the mounting seat plate, wherein a control and leveling mechanism is arranged on the mounting seat plate and located on the side of the wire feeding driving mechanism, and the control and leveling mechanism is used for leveling the welding wire; a travel detection mechanism is arranged in the control and leveling mechanism, and the travel detection mechanism is used for detecting the travel distance of the welding wire.

[0009] A connecting rod is arranged on the mounting seat plate and located on the side of the control and leveling mechanism, a mounting plate is arranged on the top of the connecting rod, and a micrometer is mounted on the top of the mounting plate, and the micrometer is used for detecting the outer diameter of the cross section of the welding wire.

[0010] A support rod is arranged on the mounting seat plate and located on the side of the connecting rod, a wire feeding mechanism is mounted on the support rod, the wire feeding mechanism is used for feeding the welding wire, connecting plates are mounted on the sides of the wire feeding mechanism, an electric telescopic rod is mounted on one of the connecting plates, and a tension meter is connected to the top rod of the electric telescopic rod, the traction end of the tension meter is connected to the other connecting plate, and a distance detection mechanism is also mounted on the sides of the wire feeding mechanism, and the distance detection mechanism is used for detecting the distance state of the wire feeding mechanism clamping the welding wire.

[0011] A control mechanism is arranged on the front part of the mounting seat plate, the control mechanism is used for receiving external control signals, controlling the operation of the wire feeding driving mechanism and the wire feeding mechanism, controlling the flow and on-off of the CO2 gas in the gas feeding and wire feeding mechanism, and controlling the electric telescopic rod to effectively hold and feed the welding wire with different cross-sectional diameters under the input signals of the travel detection mechanism, the micrometer, the tension meter and the distance detection mechanism.

[0012] Compared with the prior art, the automobile frame welding robot automatic wire feeding system of the present application has the following advantages:

[0013] The automatic wire feeding system for the automobile frame welding robot in the application, in the process of acquiring the section outer diameter of the welding wire measured by the micrometer in the control mechanism, when the acquired welding wire outer diameter changes, under the intervention of the stroke displacement data, the cumulative time counting point control electric telescopic rod ejector rod retracts, the laser ranging sensor real-time monitors the downward movement of the action process and controls the retracting amount of the electric telescopic rod ejector rod, and the retracting amount of the electric telescopic rod ejector rod is compared with the standard retracting amount according to the tension value acquired by the tension meter, and the retracting amount of the electric telescopic rod ejector rod is compensated, so that when the welding wire diameter changes, the wire feeding mechanism can effectively and stably press and feed the welding wire into the wire feeding pipe, avoiding the situation that the welding wire appears "fast" or "slow" at the moment, under the stable welding program control, the situation that the melted welding wire blocks the electric nozzle is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a top view schematic diagram of the application;

[0015] Figure 2 It is a partial cutaway schematic diagram of Figure 1

[0016] Figure 3 It is a front view schematic diagram of the application;

[0017] Figure 4 It is a partial cutaway schematic diagram of the control adjusting mechanism of the application;

[0018] Figure 5 It is a partial cutaway schematic diagram of the stroke detection mechanism of the application;

[0019] Figure 6 It is a schematic diagram of the micrometer installation of the application;

[0020] Figure 7 It is a partial cutaway schematic diagram of the wire feeding mechanism of the application;

[0021] Figure 8 It is a partial cutaway schematic diagram of the three-way and wire feeding plug cooperation of the application;

[0022] Figure 9 It is a cutaway schematic diagram of the control box of the application;

[0023] Figure 10 It is a schematic diagram of the connection of each module in the development board of the application.

[0024] ​In the diagram: 1. Mounting base plate, 2. Support plate, 3. Frame plate, 4. Slide rod, 5. Motor 1, 6. Lead screw, 7. Sliding plate, 8. Motor 2, 9. Mounting disc, 10. Mounting pin, 11. Welding wire reel, 12. Plug, 13. Spinning disc, 14. Frame rod, 16. Mounting frame 1, 17. Leveling wheel, 18. Connecting pipe, 19. Sliding rod, 20. Support spring, 21. Mounting frame 2, 22. Encoder, 23. Moving wheel, 24. Connecting rod, 25. Mounting plate, 26. Micrometer, 27. Support rod, 28. Fixing frame, 29. Connecting plate, 30. Electric telescopic rod. 31 Tensile gauge, 32 Mounting support plate, 33 Laser rangefinder sensor, 34 Reflector, 35 Motor III, 36 Spinning wheel, 37 Support spindle, 38 Spinning ring I, 39 Spinning ring II, 40 Support spindle, 41 T-joint, 42 Wire feed head, 43 Sealing ring, 44 Inner bearing, 45 Solenoid valve, 46 Electronic flow control valve, 47 Air pipe, 48 Wire feed tube, 49 Mounting rod, 50 Control box, 51 Development board, 52 Driver group, 53 Integrated relay, 54 Photoelectric converter, 390 Connecting support rod. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] See Figure 1 , Figure 2 , Figure 3 and Figure 6 An automatic wire feeding system for an automotive frame welding robot includes a mounting plate 1 bolted to the welding robot's robotic arm, a wire feeding drive mechanism mounted on the left side of the mounting plate 1, a welding wire reel 11 mounted on the wire feeding drive mechanism, and a gas supply and wire feeding mechanism mounted on the right side of the mounting plate 1. A control and leveling mechanism is installed on the mounting plate 1, located to the right of the wire feeding drive mechanism, to level the welding wire. A travel detection mechanism is installed inside the control and leveling mechanism to detect the wire feeding distance.

[0027] The connecting rod 24 is bolted to the mounting plate 1 and located to the right of the control and leveling mechanism. The top of the connecting rod 24 is integrally mounted with a mounting plate 25, and the top of the mounting plate 25 is screwed to fix a micrometer 26. The micrometer 26 is a Keyence LS-9000 ultra-high speed / high precision optical micrometer. The micrometer 26 is used to detect the outer diameter of the welding wire cross section.

[0028] The support rod 27 is bolted on the mounting seat plate 1 and located at the right side of the connecting rod 24, the wire feeding mechanism is installed on the support rod 27, the wire feeding mechanism is used for feeding welding wire, the left side of the wire feeding mechanism is screw-fixed with the connecting plate 29, the lower connecting plate 29 is bolted with the electric telescopic rod 30, the electric telescopic rod 30 is a stepping motor driven electric telescopic rod, the top rod flange of the electric telescopic rod 30 is connected with the base of the tension meter 31, the traction end of the tension meter 31 is bolted on the bottom of the upper connecting plate 29, the side of the wire feeding mechanism is also provided with a distance detection mechanism, the distance detection mechanism is used for detecting the distance state of the wire clamped by the wire feeding mechanism.

[0029] The front of the mounting seat plate 1 is provided with a control mechanism, the control mechanism is used for receiving external control signals, and the control mechanism controls the operation of the wire releasing driving mechanism and the wire feeding mechanism, controls the on-off of the CO2 gas flow in the wire feeding mechanism, and controls the electric telescopic rod 30 to drive the wire feeding mechanism to effectively hold and move the welding wire with different cross-sectional diameters under the input signals of the walking distance detection mechanism, the micrometer 26, the tension meter 31 and the laser ranging sensor 33.

[0030] Therefore, under the control mechanism, in addition to being able to receive the welding robot wire feeding on-off signal to control the operation of the wire releasing driving mechanism and the wire feeding mechanism, the wire feeding mechanism can effectively hold the wire diameter change area and effectively move the wire in the case of wire diameter change.

[0031] Referring to Figure 1 , Figure 2 and Figure 3 , the wire releasing driving mechanism includes a support plate 2 bolted on the left rear of the mounting seat plate 1 and a frame plate 3 bolted on the left front of the mounting seat plate 1, the support plate 2 and the frame plate 3 are bolted with the slide rod 4 symmetrically left and right, the slide rod 4 is slidably sleeved with the sliding plate 7, the rear of the support plate 2 is bolted with the motor 1 5, the motor 1 5 is a stepping motor, the rotor shaft of the motor 1 5 penetrates through the support plate 2 and is flange-connected with the lead screw 6, the lead screw 6 is screwed on the sliding plate 7 and the front end of the lead screw 6 is rotationally arranged on the frame plate 3, wherein the center position of the frame plate 3 is provided with a bearing groove, the bearing groove is inserted into the inner ring of the bearing by interference, and the front end of the lead screw 6 is inserted into the inner ring of the bearing by interference, so as to effectively support the stable rotation of the lead screw 6.

[0032] The front of the sliding plate 7 is bolted with the motor 2 8, the motor 2 8 is a stepping motor, the rotor shaft of the motor 2 8 penetrates through the sliding plate 7 and is flange-connected with the installation rotary disc 9, the center position of the installation rotary disc 9 is bolted with the installation insertion column 10, the installation insertion column 10 is slidably sleeved with the welding wire reel 11, the installation insertion column 10 penetrates out of the rear end of the welding wire reel 11 and is threadedly locked with the rotary pressure disc 13, the rear of the installation rotary disc 9 is integrally provided with the plug 12 and the plug 12 is inserted into the insertion groove arranged on the front end of the welding wire reel 11.

[0033] The lead of the screw rod 6 and the sliding plate 7 is 4 times of the standard welding wire cross-sectional diameter.

[0034] Therefore, the welding wire reel 11 can be moved forward and backward by the rotation of the motor 5, and the welding wire reel 11 on the sliding plate 7 can be moved more stably through the sliding cooperation of the sliding rod 4 and the sliding plate 7. The motor 8 can drive the rotation of the welding wire reel 11. When the motor 5 rotates, the motor 8 rotates one circle, and then the motor 5 drives the screw rod 6 to rotate 0.25 turns. The length of the winding area of the welding wire reel 11 is 100 times of the standard welding wire cross-sectional diameter. When the motor 5 rotates 25 turns in one direction, it will rotate 25 turns in the other direction, and the process is repeated.

[0035] In this way, the welding wire on the welding wire reel 11 can be regularly sent out, avoiding the scattering of the welding wire on the welding wire reel 11.

[0036] Referring to Figure 1 , Figure 2 , Figure 3 , Figure 4 , the control adjustment mechanism includes a frame rod 14 fixed on the seat plate 1 and located on the right side of the wire feeding driving mechanism. The top of the frame rod 14 is fixedly installed with a frame one 16. The frame one 16 is a square frame with two open ends. The frame one 16 is symmetrically and rotatably provided with leveling wheels 17 on the left and right sides. The wheel groove of the leveling wheel 17 is a semicircular structure, and the side parts of the leveling wheels 17 at the upper and lower positions are in close contact with each other. When the two leveling wheels 17 are in close contact, the wheel grooves of the two wheels are in a clamping state and cover the welding wire, so that the welding wire is effectively leveled when the wire feeding mechanism is running, and the welding wire moves more smoothly in the wire moving pipe.

[0037] Referring to Figure 4 and Figure 5 , the walking distance detection mechanism includes a connecting pipe 18 fixedly screwed in the top of the frame one 16. A sliding rod 19 is slidably arranged in the connecting pipe 18. The sliding rod 19 is a circular rod structure with a square plate integrally arranged at the upper end. The square plate is slidably arranged in the square inner cavity of the connecting pipe 18. The bottom of the sliding rod 19 is fixedly installed with a frame two 21. The frame two 21 is a square frame with open front and rear ends. A supporting spring 20 is arranged in the connecting pipe 18, and the lower end of the supporting spring 20 is supported on one end of the sliding rod 19. The supporting spring 20 is a compression and rebound type, and the elasticity of the supporting spring 20 satisfies that the inner wall of the wheel groove of a driving wheel 23 is effectively clamped on the welding wire. An encoder 22 is fixedly screwed on the front side of the frame two 21. The encoder 22 is an absolute type distance encoder. The driving shaft of the encoder 22 penetrates through one side of the frame two 21 and is connected to the center of the driving wheel 23 by interference keying. The wheel groove of the driving wheel 23 is provided with anti-skid lines, and the wheel groove of the driving wheel 23 clamps the welding wire.

[0038] When the welding wire diameter part passes through the driving wheel 23, under the elastic support of the support spring 20, the wheel groove of the driving wheel 23 is effectively pressed on the welding wire, and in the process of the welding wire being sent, the driving wheel 23 rotates, the encoder 22 outputs the rotation pulse count signal in real time, the welding wire transverse movement P is known when the driving wheel 23 rotates one round, the rotation number J is obtained by analyzing the rotation pulse count signal, and the welding wire transverse displacement length r is calculated.

[0039] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 7 , the wire feeding mechanism comprises upper and lower symmetrical fixed frames 28, the lower fixed frame 28 is bolted on the top of the support fixed rod 27, the connecting plate 29 is bolted on the rear side of the fixed frame 28, the front side of the fixed frame 28 is bolted with the motor three 35, the motor three 35 is a stepping motor, the rotor shaft of the motor three 35 penetrates through the fixed frame 28 and is in interference key connection with the front end center position of the spinning wheel 36, the rear end center position of the spinning wheel 36 is flange connected with the support rotating shaft 37 which is rotationally arranged on the fixed frame 28, the rear end of the fixed frame 28 is provided with a bearing groove, the bearing groove is interference inserted with a bearing, and the support rotating shaft 37 is interference inserted with the inner ring of the bearing, so as to ensure the stable rotation of the spinning wheel 36.

[0040] Among them, the upper spinning wheel 36 is adhesively connected with a spinning ring one 38 made of neoprene, the middle part of the spinning ring one 38 is provided with an arc pressing groove, in the natural state, the deepest part of the arc pressing groove is half of the radius of the welding wire, and when the spinning ring one 38 is pressed, the inner wall of the arc pressing groove can be pressed on the upper side of the welding wire, the lower spinning wheel 36 is interference embedded with a spinning ring two 39 made of aluminum, the outer side of the spinning ring two is embedded with a support spinning ring 40 made of tungsten-chromium-cobalt alloy, the middle side of the support spinning ring 40 is provided with an inner bearing groove, the cross section of the inner bearing groove is a semicircular groove, which can effectively press the lower half of the welding wire section on the standard section outer diameter, and the inner wall of the inner bearing groove is circumferentially provided with V-shaped anti-skid lines at an interval of 0.01 millimeters.

[0041] When the top rod of the electric telescopic rod 30 is retracted, the arc pressing groove of the spinning ring one 38 effectively presses the welding wire in the inner bearing groove, when the upper motor three 35 rotates counterclockwise and the lower motor three 35 simultaneously rotates clockwise at the same speed, the welding wire can be effectively sent into the wire pipe.

[0042] Referring to Figure 7 , the distance detection mechanism comprises mounting support plates 32 integrally arranged on the rear side of each fixed frame 28, the upper mounting support plate 32 is screw fixed with a laser ranging sensor 33, and the lower mounting support plate 32 is pasted with a reflecting plate 34 corresponding to the position on the laser ranging sensor 33.

[0043] The laser distance sensor 33 is a Keyence LK-H020 laser distance sensor. In the process of obtaining the cross-sectional outer diameter of the welding wire measured by the micrometer 26 in real time, the downward movement amount w of the electric telescopic rod 30 is obtained by analyzing the welding wire outer diameter change amount d in real time, and the laser distance sensor 33 monitors the downward movement amount in the action process in real time until d = w.

[0044] The standard tension e of the tension gauge 31 is set. When the tension T obtained by the tension gauge 31 in real time is equal to e, the telescopic state of the electric telescopic rod 30 at this time is maintained. When the tension T obtained by the tension gauge 31 in real time is greater than e, the electric telescopic rod 30 is controlled to move upward as an action signal of the extension of the top rod of the electric telescopic rod 30, until the tension T is equal to e, and the electric telescopic rod 30 is controlled to stop running. When the tension T obtained by the tension gauge 31 in real time is less than e, the electric telescopic rod 30 is controlled to move downward as an action signal of the retraction of the top rod of the electric telescopic rod 30, until the tension T is equal to e, and the electric telescopic rod 30 is controlled to stop running. The standard tension e satisfies that the maximum resistance that can be overcome to transfer the welding wire is 50 Newton, and the welding wire will not slip before the pressure arc ring groove and the inner support ring groove in the process of being pressed by the wire feeding mechanism.

[0045] Therefore, the distance data is used as a priority control signal, and the tension is used as a complementary control signal. In this way, when the pressure arc ring groove and the inner support ring groove are worn out after a long time of pressing and feeding the welding wire, the welding wire can be effectively guaranteed to be pressed by the inner wall of the pressure arc ring groove and the inner support ring groove, so that the welding wire can be effectively fed.

[0046] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 8 , the gas and wire feeding mechanism includes a connecting support rod 390 fixed on the right side of the mounting seat plate 1 by bolts, the top of the connecting support rod 390 is fixed with a tee joint 41 by screws, the left end of the tee joint 41 is threadedly locked with a wire pressing head 42, the left end of the tee joint 41 is also provided with a sealing ring 43, and the end side of the wire pressing head 42 is pressed against the sealing ring 43.

[0047] The center of the wire pressing head 42 is bonded with an inner support 44, the right end of the inner support 44 is slidably sealed on the welding wire, and the material of the inner support is hydrogenated nitrile rubber. The moving resistance of the standard outer diameter welding wire is 4 Newton, and the moving resistance of the minimum diameter welding wire is 2 Newton. In this way, when the carbon dioxide gas enters the tee joint 41, it is avoided to be discharged through the gap between the inner support 44 and the welding wire.

[0048] The rear end of the tee joint 41 is connected with an electromagnetic valve 45 by a double-end wire connection, the gas inlet port of the electromagnetic valve 45 is connected with an electronic flow control valve 46 by a double-end wire connection, the gas inlet of the electronic flow control valve 46 is connected with an external CO2 compressed gas tank through a gas connection pipe 47, and the right end of the tee joint 41 is connected with a movable joint of a wire pipe 48 by screwing.

[0049] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 9 , the control mechanism includes a mounting seat plate 1 front bolted mounting rod 49, the top of the mounting rod 49 screw fixed control box 50, the control box 50 in the left side of the upper part of the development board 51 is bolted with insulating pad, the control box 50 in the lower side of the development board 51 is bolted with driver group 52 and integrated relay 53, the right side of the control box 50 is bolted with photoelectric converter 54.

[0050] The power supply controlled end of motor one 5, motor two 8, electric telescopic rod 30, motor three 35 is connected with the power supply control end of each driver of driver group 52 through cable, the main power supply connection end of driver group 52 is connected with external power supply through cable, and the speed control unit in the driver is modulated in advance, so that motor one 5 and motor two 8 meet the uniform and regular release process of welding wire, under the operation of motor three 35, the welding wire between the wire driving mechanism and the wire feeding mechanism is in a straight state, and the two motor threes 35 rotate synchronously and reversely, and the telescopic speed of electric telescopic rod 30 is 1 m / s.

[0051] The main power supply connection end of integrated relay 53 is connected with external power supply through cable, and the potential control end of integrated relay 53 is connected with the potential controlled end of electromagnetic air valve 45 through cable.

[0052] Referring to Figure 10 , the development board 51 includes stroke pulse signal receiving module, distance signal receiving module, tension signal receiving module, flow signal receiving module, outer diameter measurement signal receiving module and control signal receiving module, the stroke pulse signal receiving module is used for receiving the pulse signal of encoder 22, the transmission line of encoder 22 is connected with the signal input pin of stroke pulse signal receiving module, encoder 22 outputs the rotation pulse count signal to stroke pulse signal receiving module in real time, and the number of revolutions J is obtained by stroke pulse signal receiving module by analyzing the rotation pulse count signal, the transverse movement amount P of welding wire is known when the rotating wheel 23 rotates one round, and the transverse displacement length r of welding wire is obtained as J*P.

[0053] The distance signal receiving module is used for receiving distance data of the laser ranging sensor 33, and a transmission line of the laser ranging sensor 33 is connected to a receiving port of the distance signal receiving module; the tension signal receiving module is used for receiving a tension signal input by the tension gauge 31 in real time, a transmission line of the tension gauge 31 is connected to a signal input pin of the tension signal receiving module, and a signal is converted into a tension value by the tension signal receiving module; the flow signal receiving module is used for receiving a gas flow signal input by the electronic flow control valve 46 in real time, a data signal output end of the electronic flow control valve 46 is connected to a signal input pin of the flow signal receiving module through a signal line, and the gas flow signal is converted into gas flow data; the outer diameter measurement signal receiving module is used for receiving cross-section outer diameter data of the micrometer 26 in real time, and a transmission line of the micrometer 26 is connected to a signal input pin of the outer diameter signal receiving module; the control signal receiving module is used for receiving an optical fiber signal output end of the photoelectric converter 54 in real time, and an electrical signal input end of the photoelectric converter 54 is connected to an electrical signal output end of the welding torch gas control and wire feeding control module of the robot through a signal line; the welding torch gas control and wire feeding control module is coordinated with the operation of the welding robot, that is, when the mechanical arm of the welding robot controls the welding torch to move away from the welding area, a stop operation instruction of the wire feeding mechanism and the wire driving mechanism is sent, and a gas cut-off instruction is sent at the same time; conversely, an operation instruction of the wire feeding mechanism and the wire driving mechanism is sent, and a gas on instruction is sent at the same time;

[0054] The travel pulse signal receiving module, the distance signal receiving module, the tension signal receiving module, the flow signal receiving module, the outer diameter measurement signal receiving module and the control signal receiving module are transmission-connected with the analysis processing module, and the analysis processing module is transmission-connected with a steering rotation number control input module one, a steering rotation number control input module two, a steering rotation number control input module three, a steering rotation number control input module four, a relay signal control input module and a flow signal control input module;

[0055] The steering rotation number control input module one is used for controlling the operation of the motor one 5, the steering rotation number control input module two is used for controlling the operation of the motor two 8, the steering rotation number control input module three is used for controlling the operation of the electric telescopic rod 30, the steering rotation number control input module four is used for controlling the operation of the motor three 35, the relay signal control input module is used for controlling the on-off of the electromagnetic gas valve 45, and the flow signal control input module is used for controlling the adjustment of the gas flow by the electronic flow control valve 46;

[0056] The analysis processing module is used for receiving the control signal in real time, issuing operation instructions to the motor one 5, the motor two 8 and the motor three 35, issuing on-off instructions to the electromagnetic gas valve 45, and used for analyzing the pulse signal into travel distance data in real time, and recording the wire feeding time from the welding wire outer diameter detection part to the pressing part of the spinning wheel 36 when the change amount of the cross-section outer diameter data reaches the action variable, and controlling the telescopic operation of the electric telescopic rod 30 when the wire feeding time is reached;

[0057] The wire feed speed K, the wire micrometer 26 measures the outer diameter position and the spinning wheel 36 pressure tight distance B are known, the analysis processing module caches the wire outer diameter data input by the micrometer 26 in real time within 2 seconds according to the time interval of 0.01 s, and compares the wire outer diameter change d of adjacent time intervals, wherein the maximum acceptable wire outer diameter difference is H, when d>H, the action variable is reached, and the time is taken as the timing point, and the stroke pulse signal at this time is taken as the stroke zero point, the wire transverse displacement length r is accumulated and calculated, until r=B, and the cumulative time reaches r / K, the control electric telescopic rod 30 ejector rod retraction instruction is sent to the steering and turning numerical control module three, and in the retracting process of the electric telescopic rod 30, the real-time monitoring of the action process downward movement is received by the laser ranging sensor 33, until d=w, in the process, when the tension T=e obtained by the tension meter 31, the electric telescopic rod 30 stop running instruction is sent to the steering and turning numerical control module three, when the tension T>e obtained by the tension meter 31 in real time, as the action signal of the electric telescopic rod 30 ejector rod extension, the control electric telescopic rod 30 ejector rod moves upward, until the tension T=e, the electric telescopic rod 30 stop running instruction is sent to the steering and turning numerical control module three, when the tension T

[0058] When d≤H, the electric telescopic rod 30 stop running instruction is sent to the steering and turning numerical control module three.

[0059] The value of H satisfies: when d=H, the wire feeding mechanism can cooperate with the control signal to stably spin the wire, and the moving resistance O of the inner support 44 to the wire area is 4N≥O≥2N.

[0060] In addition, the spinning wheel 36 pressure tight position and the inner support 44 right port pressure cover position wire distance G and the standard gas flow FL / min are known, the analysis processing module takes the wire outer diameter change as the threshold, when the cumulative time reaches B / K, the timing will continue, until the time reaches (B+G) / K, the signal control electronic flow control valve 46 outputs gas with a flow of (F / 2) L / min, and the signal control electronic flow control valve 46 outputs gas with a flow of F L / min after a delay of 0.5 seconds.

[0061] Under such a setting, in the case of slight wear of the inner support 44 right port, the influence on the cooperation area of the two can be weakened by instantaneously reducing the gas flow when the wire diameter changes in the area passing through the inner support 44 right port.

[0062] The working principle of the embodiment is as follows: when the robot welding gun gas control wire feeding control module sends a wire feeding mechanism and a wire feeding driving mechanism operation instruction, the control mechanism sends an operation instruction to the motor 5, the motor 8 and the motor 3, and sends an electromagnetic valve 45 opening valve instruction to the relay signal control module. The wire feeding mechanism, the wire feeding driving mechanism and the gas feeding and wire feeding mechanism run coordinately, so that the gas and the welding wire are stably input into the wire pipe 48.

[0063] In the process of the control mechanism acquiring the cross-sectional outer diameter of the welding wire measured by the micrometer 26, when the acquired welding wire outer diameter changes, the cumulative time counting point controls the retracting of the top rod of the electric telescopic rod 30 under the intervention of the stroke displacement data. The retracting amount of the top rod of the electric telescopic rod 30 is monitored in real time by the laser ranging sensor 33, and the retracting amount of the top rod of the electric telescopic rod 30 is compared with the standard tension according to the tension value acquired by the tension gauge 31. The retracting amount of the top rod of the electric telescopic rod 30 is compensated, so that the wire feeding mechanism can effectively and stably press and hold the welding wire to rotate and feed into the wire pipe 48 when the diameter of the welding wire changes, the situation of “fast feeding” or “slow feeding” of the welding wire is avoided, and the situation of the melted welding wire blocking the conductive nozzle is reduced under the stable welding program control.

[0064] The above only describes the preferred embodiments of the present application and is not used to limit the protection scope of the present application.

Claims

1. An automatic wire feeding system for an automotive frame welding robot, comprising a mounting plate mounted on the robotic arm of the welding robot, a wire feeding drive mechanism mounted on one side of the mounting plate, a welding wire reel mounted on the wire feeding drive mechanism, and a gas supply and wire feeding mechanism mounted on the other side of the mounting plate, characterized in that: A leveling control mechanism is provided on the mounting plate and located on one side of the wire feeding drive mechanism. The leveling control mechanism is used to level the welding wire. A travel detection mechanism is provided inside the leveling control mechanism. The travel detection mechanism is used to detect the wire feeding distance. A connecting rod is provided on the mounting base plate and located on one side of the control and leveling mechanism. A mounting plate is provided on the top of the connecting rod, and a micrometer is installed on the top of the mounting plate. The micrometer is used to detect the outer diameter of the welding wire cross section. A support rod is provided on the mounting base plate and on one side of the connecting rod. A wire feeding mechanism is installed on the support rod. The wire feeding mechanism is used to feed welding wire. Connecting plates are installed on both sides of the wire feeding mechanism. An electric telescopic rod is installed on one of the connecting plates, and a tension gauge is connected to the top rod of the electric telescopic rod. The traction end of the tension gauge is connected to the other connecting plate. A distance detection mechanism is also installed on the side of the wire feeding mechanism. The distance detection mechanism is used to detect the distance between the wire feeding mechanism and the welding wire. The front of the mounting plate is provided with a control mechanism. The control mechanism is used to receive external control signals and control the operation of the wire feeding drive mechanism and the wire feeding mechanism, control the CO2 gas flow rate and on / off state in the gas feeding and wire conveying mechanism, and control the electric telescopic rod to drive the wire feeding mechanism to effectively press and move welding wires of different cross-sectional diameters under the intervention of signals input from the travel detection mechanism, micrometer, tension gauge and distance detection mechanism. The wire feeding drive mechanism includes a support plate located at the rear of one side of the mounting base plate and a mounting plate located at the front of one side of the mounting base plate. Sliding rods are symmetrically arranged between the support plate and the mounting plate. A sliding plate is slidably arranged on the sliding rod. A motor is mounted on the support plate. The rotor shaft of the motor passes through the support plate and is connected to a lead screw. The lead screw is screwed onto the sliding plate, and one end of the lead screw is rotatably mounted on the mounting plate. The sliding plate is equipped with a second motor. The rotor shaft of the second motor passes through the sliding plate and is connected to an installation disc. An installation pin is installed at the center of the installation disc. A welding wire reel is sleeved on the installation pin. A screw-on pressure plate is screwed to one end of the installation pin that extends out of the welding wire reel. A plug is arranged circumferentially on the installation disc, and all plugs are inserted into slots arranged circumferentially at one end of the welding wire reel. The control and leveling mechanism includes a frame rod on the mounting base plate and located on one side of the wire feeding drive mechanism. The top of the frame rod is connected to a mounting frame. Leveling wheels are symmetrically arranged on both sides of the mounting frame. The grooves of the symmetrical leveling wheels press against the upper and lower sides of the welding wire, respectively. The travel detection mechanism includes a connecting pipe connected to the top of the inner frame of the first mounting frame. A sliding rod is slidably arranged inside the connecting pipe. The bottom of the sliding rod is connected to the second mounting frame. A support spring is arranged inside the connecting pipe, and one end of the support spring is supported on one end of the sliding rod. An encoder is installed on one side of the second mounting frame. The moving shaft of the encoder passes through one side of the second mounting frame and is connected to a moving wheel. The groove of the moving wheel is provided with anti-slip texture. The groove of the moving wheel is pressed onto the welding wire. The wire feeding mechanism includes a fixed frame arranged symmetrically at the top and bottom. The lower fixed frame is bolted to the top of the support rod. The mounting plate is connected to one side of the fixed frame. Motor 3 is installed on the other side of the fixed frame. The rotor shaft of the motor 3 passes through the fixed frame and is connected to a spinning wheel. The center of the other end of the spinning wheel is connected to a support shaft, and the support shaft is rotatably mounted on the fixed frame. The upper spinning wheel is provided with a spinning ring one, and the middle of the spinning ring one is provided with an arc-pressing ring groove; the lower spinning wheel is provided with a spinning ring two, and the outer side of the spinning ring two is provided with a supporting ring, and the middle side of the supporting ring is provided with an inner bearing ring groove. The distance detection mechanism includes mounting support plates connected to one side of each fixed frame. A laser rangefinder is mounted on one of the mounting support plates, and a reflector is mounted on the other mounting support plate at a position corresponding to the laser rangefinder. The air supply and wire feeding mechanism includes a connecting support rod connected to the other side of the mounting base plate. A tee is connected to the top of the connecting support rod. A wire feeding head is screwed to one end of the tee. A sealing ring is also provided at one end of the tee. The sealing ring is pressed against the end side of the wire feeding head. The wire feeding head is provided with an inner bearing at its center, and one end of the inner bearing is softly covered with the welding wire; The rear port of the tee is connected to a solenoid valve, the inlet port of the solenoid valve is connected to an electronic flow control valve, the inlet of the electronic flow control valve is connected to an external CO2 compressed gas tank through a gas pipe, and the other port of the tee is connected to a wire feed tube.

2. The automatic wire feeding system for automotive frame welding robots according to claim 1, characterized in that: The control mechanism includes a mounting rod located at the front of the mounting base plate, a control box connected to the top of the mounting rod, a development board located on one side of the control box, a driver assembly and an integrated relay located inside the control box and below the development board, and a photoelectric converter located on the other side of the control box.

3. The automatic wire feeding system for automotive frame welding robots according to claim 2, characterized in that: The development board includes a stroke pulse signal receiving module, a distance signal receiving module, a tension signal receiving module, a flow signal receiving module, an outer diameter measurement signal receiving module, and a control signal receiving module. The stroke pulse signal receiving module is used to receive pulse signals from the encoder. The distance signal receiving module is used to receive distance data from the laser rangefinder. The tension signal receiving module is used to receive the tension signal input from the tension gauge in real time. The flow signal receiving module is used to receive the gas flow signal input from the electronic flow control valve in real time. The outer diameter measurement signal receiving module is used to receive the outer diameter data of the micrometer section in real time. The control signal receiving module is used to receive the fiber optic signal output from the photoelectric converter in real time. The stroke pulse signal receiving module, distance signal receiving module, tension signal receiving module, flow signal receiving module, outer diameter measurement signal receiving module, and control signal receiving module are connected to an analysis and processing module. The analysis and processing module is connected to a steering wheel CNC input module 1, a steering wheel CNC input module 2, a steering wheel CNC input module 3, a steering wheel CNC input module 4, a relay signal control input module, and a flow signal control input module. The first steering rotary CNC input module is used to control the operation of the first motor, the second steering rotary CNC input module is used to control the operation of the second motor, the third steering rotary CNC input module is used to control the operation of the electric telescopic rod, the fourth steering rotary CNC input module is used to control the operation of the third motor, the relay signal input module is used to control the on / off state of the electromagnetic valve, and the flow signal input module is used to control the electronic flow control valve to regulate the gas flow. The analysis and processing module is used to receive control signals in real time, issue running commands to motor one, motor two and motor three, and issue on / off commands to the solenoid valve. It is also used to parse the pulse signal into travel distance data in real time, and record the wire feeding time from the wire outer diameter detection part to the spinning wheel pressing part when the change in the cross-sectional outer diameter data reaches the action variable. When the wire feeding time is reached, the electric telescopic rod is controlled to extend and retract. The analysis and processing module assists in controlling the extension and retraction of the electric telescopic pole by incorporating tension and distance data.

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