Magnetic attraction synchronous walking type titanium alloy pipe welding robot protected by inert gas

Abstract

The invention discloses a magnetic attraction synchronous walking type inert gas protection titanium alloy pipe welding robot which comprises a titanium alloy pipe to be welded, an active welding robot, a follow-up inert gas protection robot and a mechanical arm. After the two titanium alloy to-be-welded pipes are coaxially spliced, a circle of to-be-welded seam is formed at the splicing position; the active welding robot walks and is attached to the outer wall face of a titanium alloy to-be-welded pipe under connection of the mechanical arm, the follow-up inert gas protection robot walks and is attached to the inner wall of the titanium alloy to-be-welded pipe, and the follow-up inert gas protection robot and the active welding robot magnetically attract each other through a magnetic attraction device. The follow-up inert gas protection robot follows the active welding robot under the action of magnetic force; and no oxidation of a welding area is realized in an invisible pipeline by the equipment.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of titanium alloy pipe welding robots. BACKGROUND

[0002] The magnetic control welding technology of titanium alloy pipe welding is to realize the synchronous walking of the inner and outer trolleys through magnetic coupling, and the core is to realize the non-contact linkage of the external B trolley and the internal A trolley by using the attraction of the internal and external magnets. The internal A trolley carries an inert gas protection cover, which accurately covers the inner wall of the weld; the external B trolley carries a welding device. Both of them move synchronously under the action of magnetic force, ensuring that the inside and outside of the weld are continuously protected by inert gas such as argon during the welding process, preventing the high-temperature oxidation of titanium alloy. This technology mainly solves the problems of insufficient internal protection and back oxidation in traditional titanium alloy pipe welding. However, the following problems exist in the technology at present:

[0003] 1. The motion precision and stability of the magnetic attraction type servo robot walking on the inner wall of the pipe are much lower than those of the active robot outside the pipe, and because the inner wall of the pipe is invisible, it is easy to be stuck by the micro-unevenness of the pipe wall (such as weld reinforcement and scratches), and motion interference is easy to occur.

[0004] 2. The gas protection effect is difficult to guarantee. If the gap between the inner wall protection cover and the pipe wall is too small (≤2mm), it is easy to be stuck due to the protrusion or deformation of the inner wall of the pipe during servo walking; if the gap is too large (>5mm), the inert gas cannot maintain positive pressure, and oxygen penetrates, causing oxidation of the titanium alloy weld. SUMMARY

[0005] The purpose of the application is to overcome the deficiencies in the prior art, and to provide a magnetic attraction synchronous walking type inert gas protection titanium alloy pipe welding robot, which can realize non-oxidation in the welding area in the invisible pipe.

[0006] Technical scheme: In order to achieve the above purpose, a magnetic attraction synchronous walking type inert gas protection titanium alloy pipe welding robot of the application comprises a titanium alloy pipe to be welded, an active welding robot, a servo inert gas protection robot and a mechanical arm; after the two titanium alloy pipes to be welded are spliced coaxially, a circle of welds to be welded is formed at the splicing position;

[0007] The active welding robot walks and adheres to the outer wall of the titanium alloy pipe to be welded under the connection of the mechanical arm, and the servo inert gas protection robot walks and adheres to the inner wall of the titanium alloy pipe to be welded. The servo inert gas protection robot is magnetically attracted to the active welding robot through a magnetic attraction device, and the servo inert gas protection robot follows the active welding robot under the action of magnetic force.

[0008] Further, the active welding robot comprises a walking frame, a welding machine; the walking frame is fixed at the end of the mechanical arm, the four wheels rotatingly installed around the walking frame are tangent to the outer circumferential surface of the titanium alloy pipe to be welded; the welding machine seat is fixedly installed on the back of the walking frame, and the welding machine is fixedly installed on the welding machine seat through the welding machine support; the welding gun end of the welding machine corresponds to the weld to be welded.

[0009] Further, the walking frame close to the titanium alloy pipe to be welded is fixedly installed with a variable magnetic attraction electromagnet unit, and the magnetic field generated by the variable magnetic attraction electromagnet unit penetrates the wall of the titanium alloy pipe to be welded and generates magnetic attraction to the follow-up inert gas protection robot.

[0010] Further, the follow-up inert gas protection robot comprises a b walking frame, a permanent magnet unit and a circular arc b protective cover; the four b wheels rotatingly installed around the b walking frame are tangent to the inner wall surface of the titanium alloy pipe to be welded, and the permanent magnet unit is close to the wall of the titanium alloy pipe to be welded on one side of the b walking frame.

[0011] Further, the back side of the permanent magnet unit is fixedly provided with guide columns arranged in a rectangular array, the b walking frame is provided with ball guide sleeves arranged in a rectangular array, each guide column is guided and matched with each ball guide sleeve, and the side of the b walking frame close to the permanent magnet unit is connected to the back side of the permanent magnet unit through a plurality of tension springs; the variable magnetic attraction electromagnet unit and the permanent magnet unit are magnetically attracted to each other, the permanent magnet unit always maintains a distance from the inner wall surface of the titanium alloy pipe to be welded under the pulling of the plurality of tension springs, the greater the magnetic attraction of the variable magnetic attraction electromagnet unit, the closer the permanent magnet unit to the inner wall surface of the titanium alloy pipe to be welded, and the greater the extension length of the tension spring.

[0012] Further, the back of the permanent magnet unit is fixedly connected with two a swing arms extending in the radial direction of the titanium alloy pipe to be welded, the two a swing arms are integrally connected with bearing seats, and the swing arm shaft is rotationally matched with the bearing seat through the bearing; the two sides of the permanent magnet unit are symmetrically provided with two circular arc support pieces, and the outer arc surface radius of the circular arc support piece is consistent with the inner wall surface radius of the titanium alloy pipe to be welded.

[0013] The concave side of each of the two circular arc support pieces is integrally connected with a b swing arm extending in the radial direction of the titanium alloy pipe to be welded, and the two ends of the swing arm shaft are fixedly connected to the ends of the two b swing arms away from the circular arc support pieces; the two sides of the end of each b swing arm close to the circular arc support piece are symmetrically connected with transverse return springs, and the ends of the transverse return springs away from the b swing arm are fixedly connected to the b walking frame through the return spring support; in the initial state, the b swing arm is substantially parallel to the a swing arm under the pulling and resetting of the plurality of transverse return springs.

[0014] The circular arc b protective cover is fixedly connected with the b swing arm through the connecting arm, the b inert gas protection bin in the circular arc b protective cover is circular arc-shaped and opens towards the inner wall surface of the titanium alloy pipe to be welded, and the end face of the circular arc b protective cover close to the inner wall surface of the titanium alloy pipe to be welded is arc-shaped and consistent with the inner diameter of the inner wall surface of the titanium alloy pipe to be welded; the inert gas flexible supply hose is further provided, and the inert gas outlet end of the inert gas flexible supply hose is communicated with the b inert gas protection bin.

[0015] Further, the variable magnetic attraction electromagnetic unit includes a gear a and a gear b, in the gear a, the variable magnetic attraction electromagnetic unit exerts a magnetic force F1 on the permanent magnet unit, and in the gear b, the variable magnetic attraction electromagnetic unit exerts a magnetic force F2 on the permanent magnet unit; F1 < F2.

[0016] In the gear b, the permanent magnet unit overcomes the tension of the tension spring under the magnetic attraction of the variable magnetic attraction electromagnetic unit, and tends to be closer to the inner wall surface of the titanium alloy pipe to be welded until the convex arc surfaces of the two circular arc support pieces are supported and fitted on the inner wall surface of the titanium alloy pipe to be welded to form a balance, in this state, the tension of the tension spring and the support force of the inner wall surface of the titanium alloy pipe to be welded on the two circular arc support pieces jointly resist the magnetic force F2 on the permanent magnet unit; in the gear b, the two circular arc support pieces are closely fitted on the inner wall surface of the titanium alloy pipe to be welded, so that the swing arm shaft is coaxial with the titanium alloy pipe to be welded, and the arc surface gap of the circular arc b protective cover is fitted on the inner wall surface of the titanium alloy pipe to be welded, if inert gas is continuously injected into the b inert gas protection bin, the inert gas entering the b inert gas protection bin can only leak through the narrow gap between the arc surface and the inner wall surface of the titanium alloy pipe to be welded, so that the b inert gas protection bin can maintain a relative positive pressure state.

[0017] In the gear a, the magnetic attraction on the permanent magnet unit is relatively small, and the permanent magnet unit is pulled away from the inner wall surface of the titanium alloy pipe to be welded under the strong pulling force of the four tension springs, so that the two circular arc support pieces and the circular arc b protective cover are further away from the inner wall surface of the titanium alloy pipe to be welded, and the two circular arc support pieces and the circular arc b protective cover are further away from and separated from the inner wall surface of the titanium alloy pipe to be welded; in this state, the tension of the tension spring alone resists the magnetic force F1 on the permanent magnet unit.

[0018] Further, the total weight G of the follow-up inert gas protection robot, 10×G < F1.

[0019] Further, a working method of a magnetic attraction synchronous walking type inert gas protection titanium alloy pipe welding robot.

[0020] Step one, the active welding robot reaches the predetermined position of the inner wall of the titanium alloy pipe to be welded, and the gear a.

[0021] Step two, enter b gear, under b gear, inject inert gas into b inert gas protection warehouse continuously.

[0022] Step three, on the basis of b gear, control the welding gun to implement spray welding on the corresponding weld, at the same time, control the mechanical arm to make the whole active welding robot rotate slowly around the axis of the titanium alloy pipe to be welded by a °, and pause after welding a small section of weld along the corresponding weld path.

[0023] Step four, on the basis of b gear, wait for a period of time.

[0024] Step five, enter a gear, under a gear, b swing arm is automatically reset under the restoring force of the transverse reset spring.

[0025] Continuously repeat the operation of "step two" to "step five" 360 / a times.

[0026] Beneficial effects: the combination of variable magnetic attraction force gear and self-adaptive mechanical structure solves the industry problem that the stability of the active robot and the sealing property of inert gas cannot be considered at the same time in titanium alloy pipe welding. The step-by-step welding process further ensures that the weld is under double gas protection throughout the process, significantly improving the welding quality and reliability of titanium alloy. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present scheme;

[0028] Figure 2 It is a schematic diagram of the overall structure of the present scheme;

[0029] Figure 3 It is a schematic diagram of the overall structure of the present scheme;

[0030] Figure 4 It is a schematic diagram of the overall structure of the present scheme; Figure 3

[0031] Figure 5 It is a schematic diagram of the overall structure of the present scheme; Figure 4

[0032] Figure 6 It is a schematic diagram of the overall structure of the present scheme; Figure 2 DETAILED DESCRIPTION

[0033] The present application will be further described below in conjunction with the drawings.

[0034] As shown in the drawings, a magnetic synchronous walking type inert gas protection titanium alloy pipe welding robot, as shown in the drawings, Figures 1 to 6 Figure 1 2 ​​​​​As shown, it comprises titanium alloy pipe to be welded 3, active welding robot 5, passive inert gas protection robot 6 and mechanical arm 1; after the coaxial splicing of the two titanium alloy pipes to be welded 3, a circle of welds to be welded 2 is formed at the splicing position, and the titanium alloy pipe to be welded 3 is installed on the fixture device.

[0035] The active welding robot 5 walks and adheres to the outer wall surface of the titanium alloy pipe to be welded 3 under the connection of the mechanical arm 1, and the passive inert gas protection robot 6 walks and adheres to the inner wall surface of the titanium alloy pipe to be welded 3, and the passive inert gas protection robot 6 is magnetically attracted to the active welding robot 5 through a magnetic attraction device, and the passive inert gas protection robot 6 follows the active welding robot 5 under the action of magnetic force.

[0036] The active welding robot 5 comprises a walking frame 15, a welding machine 19 and a protective cover 21; the walking frame 15 is fixed at the end of the mechanical arm 1, and the four-direction wheels 14 rotatably installed around the walking frame 15 are all in rolling tangential contact with the outer peripheral surface of the titanium alloy pipe to be welded 3; the welding machine seat 17 is fixedly installed on the back of the walking frame 15, the welding machine 19 is fixedly installed on the welding machine seat 17 through the welding machine support 18, the welding gun 51 at the end of the welding machine 19 corresponds to the weld to be welded 2, the protective cover 21 is fixedly connected with the welding machine support 18, the protective cover 21 is in clearance fit with the outer peripheral surface of the titanium alloy pipe to be welded 3, the inert gas protection bin 39 is in the protective cover 21, the protective cover 21 covers the outside area of the welding gun 51 at the end corresponding to the weld to be welded 2, and the inert gas spray gun 52 extending into the inert gas protection bin 39 is further included.

[0037] The variable magnetic attraction force electromagnet unit 16 is fixedly installed on the side of the walking frame 15 close to the titanium alloy pipe to be welded 3, the magnetic field generated by the variable magnetic attraction force electromagnet unit 16 penetrates through the wall of the titanium alloy pipe to be welded 3, and magnetic attraction force is generated on the passive inert gas protection robot 6.

[0038] As shown in Figures 3 to 6 The passive inert gas protection robot 6 comprises a walking frame 12, a permanent magnet unit 11 and a circular arc-shaped protective cover 7; the four-direction wheels 13 rotatably installed around the walking frame 12 are all in rolling tangential contact with the inner wall surface of the titanium alloy pipe to be welded 3, so that the clearance between the walking frame 12 and the inner wall surface of the titanium alloy pipe to be welded 3 is always kept unchanged.

[0039] The permanent magnet unit 11 is on the side of the walking frame 12 close to the wall of the titanium alloy pipe to be welded 3, four guide columns 27 in rectangular array are fixedly arranged on the back of the permanent magnet unit 11, four ball guide sleeves 26 are arranged in rectangular array on the walking frame 12, the four guide columns 27 are respectively guided and matched with the four ball guide sleeves 26, and the side of the walking frame 12 close to the permanent magnet unit 11 is connected to the back of the permanent magnet unit 11 through a plurality of tension springs 25.

[0040] The variable magnetic attraction electromagnet unit 16 is magnetically attracted to the permanent magnet unit 11, and the permanent magnet unit 11 is always kept away from the inner wall surface of the titanium alloy pipe to be welded under the pulling of a plurality of tension springs 25. The greater the magnetic attraction force applied by the variable magnetic attraction electromagnet unit 16, the closer the permanent magnet unit 11 to the inner wall surface of the titanium alloy pipe to be welded, and the greater the extension length of the tension spring 25. The back surface of the permanent magnet unit 11 is fixedly connected with two a swing arms 9 extending along the radial direction of the titanium alloy pipe to be welded. The two a swing arms 9 are integrally connected with bearing seats 60 at the ends thereof. The device further comprises a swing arm shaft 8 rotatably connected with the bearing seats 60 through bearings. The two sides of the permanent magnet unit 11 are symmetrically provided with two arc support plates 28. The outer arc surface radius of the arc support plate 28 is consistent with the inner wall surface radius of the titanium alloy pipe to be welded. The concave side of the two arc support plates 28 is integrally connected with a b swing arm 10 extending along the radial direction of the titanium alloy pipe to be welded. The two ends of the b swing arm 10 away from the arc support plate 28 are fixedly connected with the two ends of the swing arm shaft 8, respectively. The two sides of the end of each b swing arm 10 close to the arc support plate 28 are symmetrically connected with a horizontal reset spring 23. The end of each horizontal reset spring 23 away from the b swing arm 10 is fixedly connected with a b walking vehicle frame 12 through a reset spring support 24. In the initial state, the b swing arm 10 is basically parallel to the a swing arm 9 under the pulling reset of a plurality of horizontal reset springs 23.

[0041] The arc-shaped b protective cover 7 is fixedly connected with the b swing arm 10 through a connecting arm 41. The b protective cover 7 is an arc-shaped b inert gas protection bin 31 with an opening facing the inner wall surface of the titanium alloy pipe to be welded. The end face of the b protective cover 7 close to the inner wall surface of the titanium alloy pipe to be welded is an arc surface 32 consistent with the inner diameter of the inner wall surface of the titanium alloy pipe to be welded. The device further comprises an inert gas flexible supply hose 4. The inert gas outlet end of the inert gas flexible supply hose 4 is communicated with the b inert gas protection bin 31.

[0042] The variable magnetic attraction electromagnet unit 16 comprises a gear a and a gear b. In the gear a, the magnetic force applied by the variable magnetic attraction electromagnet unit 16 to the permanent magnet unit 11 is F1. In the gear b, the magnetic force applied by the variable magnetic attraction electromagnet unit 16 to the permanent magnet unit 11 is F2. F1 < F2. The servo-type inert gas protection robot 6 of the present scheme is designed as a whole with lightweight materials, such as lightweight carbon fiber structure. The total weight G of the servo-type inert gas protection robot 6 is much smaller than the magnetic force F1 applied by the variable magnetic attraction electromagnet unit 16 to the permanent magnet unit 11. Specifically, at least 10 × G < F1. Therefore, no matter what posture the servo-type inert gas protection robot 6 is in, the influence of gravity on the tension spring 25 and the reset spring 23 is very small and can be ignored in the device. The total weight G of the whole machine is ≤ 3 kg (F1 ≥ 300 N), and the influence of gravity on the spring is < 5%, which ensures that the function does not change when the device is inverted.

[0043] In the b position, because the magnetic attraction of the permanent magnet unit 11 is greater, the permanent magnet unit 11 is close to the inner wall of the titanium alloy pipe to be welded under the strong magnetic attraction of the variable magnetic attraction electromagnet unit 16, overcoming the tension of the tension spring 25, until the convex arc surface of the two arc support plates 28 supports and adheres to the inner wall of the titanium alloy pipe to be welded, forming a balance, in this state, the tension of the tension spring 25 and the support force of the inner wall of the titanium alloy pipe to be welded on the two arc support plates 28 jointly resist the magnetic force F2 of the permanent magnet unit 11, wherein the support force of the inner wall of the titanium alloy pipe to be welded on the two arc support plates 28 is at least half of the size of F2; in the b position, the two arc support plates 28 closely adhere to the inner wall of the titanium alloy pipe to be welded, so that the swing arm shaft 8 is coaxial with the titanium alloy pipe to be welded, and the arc surface 32 of the arc-shaped b protective cover 7 is gap-fitted with the inner wall of the titanium alloy pipe to be welded, the gap is less than 2mm, in this state, if inert gas is continuously injected into the b inert gas protection bin 31, the inert gas entering the b inert gas protection bin 31 can only leak through the narrow gap between the arc surface 32 and the inner wall of the titanium alloy pipe to be welded, so that the b inert gas protection bin 31 can maintain a relative positive pressure state, thereby preventing external oxygen from flowing into the b inert gas protection bin 31.

[0044] In the a position, because the magnetic attraction of the permanent magnet unit 11 is relatively small, the permanent magnet unit 11 is farther away from the inner wall of the titanium alloy pipe to be welded under the strong pulling force of the four tension springs 25, so that the two arc support plates 28 and the arc-shaped b protective cover 7 are farther away from the inner wall of the titanium alloy pipe to be welded, and the two arc support plates 28 and the arc-shaped b protective cover 7 are farther away from and separated from the inner wall of the titanium alloy pipe to be welded; in this state, the tension of the tension spring 25 alone resists the magnetic force F1 of the permanent magnet unit 11.

[0045] The working method and principle of the application:

[0046] Step one, in the initial state, the active welding robot 5 is attached to the outer wall of the titanium alloy pipe to be welded under the driving of the mechanical arm 1, and the end of the welding gun 51 corresponds to the weld seam 2, at this time the a protective cover 21 is arranged outside the area corresponding to the weld seam 2 at the end of the welding gun 51; at the same time, the inert gas protection robot 6 in the a position follows the active welding robot 5 to the predetermined position of the inner wall of the titanium alloy pipe to be welded under the action of the magnetic force, so that the b inert gas protection bin 31 of the arc-shaped b protective cover 7 is arranged in the area corresponding to the weld seam 2 inside the end of the welding gun 51, at this time because it is in the a position, the arc surface 32 of the arc-shaped b protective cover 7 is away from the inner wall of the titanium alloy pipe to be welded by a distance of more than 5mm, at this time if the inert gas injected into the b inert gas protection bin 31 easily escapes, and it is difficult to maintain a positive pressure;

[0047] The purpose of entering the a gear: in the a gear, the two arc support pieces 28 and the arc-shaped b protective cover 7 are more far away and separated from the inner wall surface of the titanium alloy pipe to be welded 3, the separation distance is greater than 6mm, completely avoiding the interference of walking, only four b four-direction wheels 13 are in rolling tangency with the inner wall surface of the titanium alloy pipe to be welded 3; in this state, the follow-up inert gas protection robot 6 will not cause motion interference due to the slight bulge and slight deformation of the inner wall surface of the titanium alloy pipe to be welded 3, the micro-unevenness such as weld reinforcement, scratches, and the like.

[0048] Step two, control the variable magnetic force electromagnet unit 16 of the active welding robot 5 to enter the b gear, in the b gear, the magnetic attraction force received by the permanent magnet unit 11 is greater, the permanent magnet unit 11 overcomes the tension of the tension spring 25 under the strong magnetic attraction of the variable magnetic force electromagnet unit 16, so that the permanent magnet unit 11 tends to be closer to the inner wall surface of the titanium alloy pipe to be welded 3, until the convex arc surface of the two arc support pieces 28 supports and adheres to the inner wall surface of the titanium alloy pipe to be welded 3 to form a balance, in this state, the tension of the tension spring 25 and the support force of the inner wall surface of the titanium alloy pipe to be welded 3 on the two arc support pieces 28 jointly resist the magnetic force F2 received by the permanent magnet unit 11, wherein the support force of the inner wall surface of the titanium alloy pipe to be welded 3 on the two arc support pieces 28 is at least half the size of F2; in the b gear, the two arc support pieces 28 closely adhere to the inner wall surface of the titanium alloy pipe to be welded 3, so that the swing arm shaft 8 is coaxial with the titanium alloy pipe to be welded 3, and at this time the arc surface 32 of the arc-shaped b protective cover 7 is more close to the inner wall surface of the titanium alloy pipe to be welded 3, so that the gap between the arc surface 32 of the arc-shaped b protective cover 7 and the inner wall surface of the titanium alloy pipe to be welded 3 is less than 2mm, in this state, the inert gas flexible supply hose 4 continuously injects inert gas into the b inert gas protection bin 31, the inert gas in the b inert gas protection bin 31 can only leak through the narrow gap between the arc surface 32 and the inner wall surface of the titanium alloy pipe to be welded 3, so that the b inert gas protection bin 31 can maintain a relative positive pressure state, thereby preventing external oxygen from flowing into the b inert gas protection bin 31, and further maintaining the inside area of the weld seam 2 corresponding to the end of the welding gun 51 in a continuous inert gas environment.

[0049] Step three, on the basis of the b gear, control the welding gun 51 to implement spray welding on the corresponding weld seam 2, at the same time, control the mechanical arm 1 to slowly rotate the active welding robot 5 as a whole around the axis of the titanium alloy pipe to be welded 3 by a°, a°≤5°, and a as an integer can be divided by 360, so that the welding gun 51 slowly welds a small section of the weld seam along the path of the corresponding weld seam 2 and then pauses.

[0050] In the process of the active welding robot 5 rotating a° around the axis of the titanium alloy pipe 3 to be welded, the permanent magnet unit 11 and the b walking frame 12 follow the variable magnetic attraction electromagnet unit 16 of the active welding robot 5 rotating a° around the axis of the titanium alloy pipe 3 to be welded under the strong magnetic attraction F2, while the two arc-shaped support pieces 28 closely fitted to the inner wall surface of the titanium alloy pipe 3 to be welded remain stationary, so that the arc-shaped b protective cover 7 remains stationary in this step, so that the b swing arm 10 and the a swing arm 9 change from parallel to an angle a° with each other, and the transverse reset spring 23 elastically deforms and stores elastic potential energy.

[0051] In this step, the welding torch 51 is always inside the b inert gas protection cabin 31 along the welding path of the corresponding weld 2, thereby effectively preventing the welding torch 51 from being oxidized along the inner side of the corresponding weld 2 in this step.

[0052] Step four, on the basis of keeping b gear, wait for a period of time, more than 30s, so that the small section of weld that has been completed in the process of "step three" is cooled under the cage of inert gas.

[0053] Step five, control the variable magnetic attraction electromagnet unit 16 of the active welding robot 5 to enter a gear. In a gear, because the magnetic attraction received by the permanent magnet unit 11 is relatively small, the permanent magnet unit 11 is farther away from the inner wall surface of the titanium alloy pipe 3 to be welded under the strong pulling force of the four tension springs 25, so that the two arc-shaped support pieces 28 and the arc-shaped b protective cover 7 are farther away from the inner wall surface of the titanium alloy pipe 3 to be welded, and the two arc-shaped support pieces 28 and the arc-shaped b protective cover 7 are farther away from and separated from the inner wall surface of the titanium alloy pipe 3 to be welded; In this state, the tension of the tension spring 25 alone resists the magnetic force F1 received by the permanent magnet unit 11; It should be noted that the follow-up inert gas protection robot 6 of the present scheme is designed with lightweight materials as a whole, and the total weight G of the follow-up inert gas protection robot 6 is much smaller than the magnetic force F1 exerted by the variable magnetic attraction electromagnet unit 16 on the permanent magnet unit 11, specifically at least 10×G<F1, so no matter what posture the follow-up inert gas protection robot 6 is in, the influence of gravity on the tension spring 25 and the reset spring 23 is very small and can be ignored in this device.

[0054] At this time, the two arc support pieces 28 have been separated from the inner wall of the titanium alloy pipe to be welded 3, the b swing arm 10 is in a free state, and the b swing arm 10 in the free state is automatically reset under the restoring force of the transverse reset spring 23, so that the b swing arm 10 swings to be parallel to the a swing arm 9 again, and the two arc support pieces 28 and the arc-shaped b protective cover 7 swing synchronously with the b swing arm 10. Since the two arc support pieces 28 and the arc-shaped b protective cover 7 are away from the inner wall of the titanium alloy pipe to be welded 3 by a sufficient distance at this time, the two arc support pieces 28 and the arc-shaped b protective cover 7 do not interfere with obstacles such as slight protrusions on the inner wall of the titanium alloy pipe to be welded 3 during the synchronous swinging with the b swing arm 10.

[0055] At this time, the relative position relationship between the active welding robot 5 and the follow-up inert gas protection robot 6 returns to the state at the end of “step one”, and a complete welding cycle is completed.

[0056] The “step two” to “step five” are repeatedly operated 360 / a times, so that the inner and outer of a complete weld seam 2 are completely welded under inert gas protection.

[0057] The core technical effect of the patent is:

[0058] 1. Dual-gear magnetic force dynamic adjustment solves the contradiction between movement and sealing.

[0059] a gear (low magnetic force F1): the gap between the inner wall protective cover and the pipe wall is greater than 5 mm, which avoids interference caused by uneven inner wall during walking; only four-way wheels contact the pipe wall to ensure that the follow-up robot can freely follow the movement of the external active robot.

[0060] b gear (high magnetic force F2): electromagnetic supercharging (F2≥2F1) overcomes the spring force of the permanent magnet unit 11, so that the two arc support pieces 28 are pressed against the pipe wall with a pressure of ≥0.5 MPa (supporting force ≥F2 / 2), the arc support pieces 28 are tightly attached to the inner wall, the swing arm shaft 8 is forced to be coaxial with the pipe, the protective cover arc surface 32 is aligned with the pipe wall, and the gap between the protective cover arc surface 32 and the pipe wall is less than 2 mm; a positive pressure air-tight chamber is formed, the inert gas flow controller dynamically adjusts the gas supply according to the gap, so that the b protective chamber 31 maintains a positive pressure of 15-30 Pa (oxygen concentration <50 ppm): the inert gas only leaks from the micro gap, effectively isolates oxygen, and protects the welding area gas environment.

[0061] 2. Self-adaptive mechanical structure improves stability.

[0062] Spring guide system: the permanent magnet unit 11 is elastically connected to the vehicle frame through the tension spring 25 and the guide column 27, and when the magnetic force increases, it automatically approaches the pipe wall and resets when the magnetic force decreases. The transverse reset spring 23 drives the swing arm mechanism to automatically reset to the parallel state at the a gear.

[0063] 3. Step-by-step welding process, ensuring full gas protection.

[0064] Welding stage (gear b): the inner wall protection cover maintains a <2mm micro gap, forming a positive pressure airtight area covering the inside of the welding area; the mechanical arm only rotates ≤5° at a time to weld a small section, and the protection cover remains stationary to avoid damage to the seal caused by movement; cooling and resetting stage (gear a): cool for more than 30s after welding, and the weld is continuously protected by gas; switch to gear a, and the protection cover is detached from the pipe wall. The spring reset mechanism makes the swing arm parallel, and there is no interference when moving to the next work station.

[0065] This patent solves the mutual exclusion of moving freedom and static sealing in titanium alloy pipe welding through magnetic-mechanical dual-mode collaborative control. The time-sharing multiplexing strategy (gear a for movement / gear b for welding) enables the device to achieve >99% oxidation-free welding area in invisible pipes, providing a reliable tool for high-demand scenarios such as aerospace and nuclear power pipelines.

[0066] The above is only the preferred embodiment of the present application, it should be noted that for those skilled in the art, without departing from the principles of the present application, can make a number of improvements and refinements, these improvements and refinements should also be considered within the scope of the present application.

Claims

1. A magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot, characterized by: It comprises a titanium alloy pipe to be welded (3), an active welding robot (5), a follow-up inert gas protection robot (6) and a robotic arm (1); after the two titanium alloy pipes to be welded (3) are coaxially spliced, a circle of weld seam (2) is formed at the splicing position; The active welding robot (5) is connected to the robotic arm (1) and moves and is attached to the outer wall of the titanium alloy pipe to be welded (3). The follower inert gas protection robot (6) moves and is attached to the inner wall of the titanium alloy pipe to be welded (3). The follower inert gas protection robot (6) is magnetically attracted to the active welding robot (5) through a magnetic attraction device. The follower inert gas protection robot (6) follows the active welding robot (5) under the action of the magnetic force.

2. The magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 1, characterized in that: The active welding robot (5) comprises a traveling frame (15) and a welding machine (19); the traveling frame (15) is fixed at the end of a robotic arm (1), and four-way wheels (14) rotatably mounted around the traveling frame (15) are all tangent to the outer peripheral surface of a titanium alloy pipe (3) to be welded in rolling contact; a welding machine base (17) is fixedly mounted on the back of the traveling frame (15), and the welding machine (19) is fixedly mounted on the welding machine base (17) via a welding machine bracket (18); the end of a welding gun (51) of the welding machine (19) corresponds to the seam to be welded (2).

3. The magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 2, characterized in that: A variable magnetic attraction electromagnet unit (16) is fixedly installed on one side of a traveling frame (15) close to the titanium alloy pipe to be welded (3). The magnetic field generated by the variable magnetic attraction electromagnet unit (16) passes through the wall of the titanium alloy pipe to be welded (3) and generates a magnetic attraction force on the follow-up inert gas protection robot (6).

4. The magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 3, characterized in that: The follow-up inert gas protection robot (6) comprises a b traveling frame (12), a permanent magnet unit (11) and an arc-shaped b protective cover (7); b four-way wheels (13) rotatably mounted on the four sides of the b traveling frame (12) all roll tangentially with the inner wall surface of the titanium alloy pipe to be welded (3), and the permanent magnet unit (11) is located on the side of the b traveling frame (12) close to the wall of the titanium alloy pipe to be welded (3).

5. The magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 4, characterized in that: A guide column (27) distributed in a rectangular array is vertically fixed to the back side of the permanent magnet unit (11); a ball guide sleeve (26) is provided in a rectangular array on the walking frame (12); each guide column (27) guides and cooperates with each ball guide sleeve (26); and a side of the walking frame (12) close to the permanent magnet unit (11) is connected to the back side of the permanent magnet unit (11) via a plurality of tension springs (25); The variable magnetic attraction force electromagnet unit (16) and the permanent magnet unit (11) are magnetically attracted to each other. Under the pulling of a plurality of tension springs (25), the permanent magnet unit (11) always maintains a distance from the inner wall surface of the titanium alloy pipe to be welded (3). The greater the magnetic attraction force applied by the variable magnetic attraction force electromagnet unit (16), the closer the permanent magnet unit (11) is to the inner wall surface of the titanium alloy pipe to be welded (3), and the greater the stretching length of the tension spring (25).

6. The magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 5, characterized in that: Two a-swing arms (9) extending in the radial direction of the titanium alloy tube to be welded (3) are fixedly connected to both sides of the back of the permanent magnet unit (11), and the ends of the two a-swing arms (9) are integrally connected to a bearing seat (60), and also include a swing arm shaft (8) that rotates with the bearing seat (60) through a bearing; Two arc support pieces (28) are symmetrically provided on both sides of the permanent magnet unit (11), and the outer arc radius of the arc support piece (28) is consistent with the inner wall radius of the titanium alloy pipe to be welded (3); The concave sides of the two arc support pieces (28) are integrally connected with a b swing arm (10) extending in the radial direction of the titanium alloy pipe to be welded (3), and the ends of the two b swing arms (10) away from the arc support piece (28) are respectively fixedly connected to the two ends of the swing arm shaft (8); Transverse return springs (23) are symmetrically connected to both sides of one end of each b swing arm (10) close to the arc support plate (28), and one end of each transverse return spring (23) away from the b swing arm (10) is fixedly connected to the b walking frame (12) through a return spring bracket (24). In the initial state, the b swing arm (10) is basically kept parallel to the a swing arm (9) under the pulling and reset of the plurality of transverse return springs (23); The arc-shaped b protective cover (7) is fixedly connected to the b swing arm (10) through the connecting arm (41); the arc-shaped b inert gas protection chamber (31) is located inside the arc-shaped b protective cover (7) with an opening toward the inner wall surface of the titanium alloy tube to be welded (3); the end surface of the arc-shaped b protective cover (7) close to the inner wall surface of the titanium alloy tube to be welded (3) is an arc surface (32) with the same inner diameter as the inner wall surface of the titanium alloy tube to be welded (3); and the arc-shaped b protective cover (7) also includes an inert gas flexible supply hose (4), and the inert gas outlet end of the inert gas flexible supply hose (4) is connected to the b inert gas protection chamber (31).

7. The magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 6, characterized in that: The variable magnetic attraction electromagnet unit (16) includes a gear position a and a gear position b. In gear position a, the magnetic force applied by the variable magnetic attraction electromagnet unit (16) to the permanent magnet unit (11) is F1. In gear position b, the magnetic force applied by the variable magnetic attraction electromagnet unit (16) to the permanent magnet unit (11) is F2; ​​F1 < F2. In gear b, the permanent magnet unit (11) overcomes the tension of the tension spring (25) under the magnetic attraction of the variable magnetic attraction electromagnet unit (16), so that the permanent magnet unit (11) tends to be closer to the inner wall surface of the titanium alloy tube to be welded (3), until the convex arc surfaces of the two arc support pieces (28) support and fit the inner wall surface of the titanium alloy tube to be welded (3) to form a balance. In this state, the tension of the tension spring (25) and the support force of the inner wall of the titanium alloy tube to be welded (3) on the two arc support pieces (28) jointly counteract the magnetic force F2 on the permanent magnet unit (11); in gear b, the two arc support pieces ( 28) closely fits the inner wall of the titanium alloy tube to be welded (3), so that the swing arm shaft (8) is just coaxial with the titanium alloy tube to be welded (3), and the arc surface (32) of the arc-shaped b protective cover (7) at this time is gap-fitted with the inner wall of the titanium alloy tube to be welded (3). In this state, if inert gas is continuously injected into the b inert gas protection chamber (31), the inert gas entering the b inert gas protection chamber (31) can only leak through the narrow gap between the arc surface (32) and the inner wall of the titanium alloy tube to be welded (3), so that a relatively positive pressure state can be maintained in the b inert gas protection chamber (31); In gear a, since the magnetic attraction force on the permanent magnet unit (11) becomes relatively smaller, the permanent magnet unit (11) is further away from the inner wall surface of the titanium alloy tube to be welded (3) under the strong pulling force of the four tension springs (25) compared with gear b, thereby making the two arc support pieces (28) and the arc-shaped b protective cover (7) further away from the inner wall surface of the titanium alloy tube to be welded (3), making the two arc support pieces (28) and the arc-shaped b protective cover (7) further away from and separated from the inner wall surface of the titanium alloy tube to be welded (3); in this state, the tension of the tension spring (25) alone counteracts the magnetic force on the permanent magnet unit (11) as F1.

8. The magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 7, characterized in that: The total weight G of the follow-up inert gas protection robot (6) is 10×G<F1.

9. The working method of the magnetic synchronous walking inert gas shielded titanium alloy pipe welding robot according to claim 8, characterized in that: Step 1: The active welding robot (5) reaches a predetermined position on the inner wall of the titanium alloy pipe (3) to be welded, gear position a; Step 2: Entering gear position b, in gear position b, continuously injecting inert gas into the inert gas protection chamber b (31); Step 3: Based on the b gear, the welding gun (51) is controlled to spray-weld the corresponding seam to be welded (2). At the same time, the mechanical arm (1) with the active welding robot (5) is controlled to slowly rotate the entirety of the titanium alloy pipe to be welded (3) in a circumferential direction a°. The welding gun (51) slowly welds a small section of the seam along the path of the corresponding seam to be welded (2) and then pauses. Step 4: Keep the gear in B and wait for a while; Step 5: Enter gear position a. In gear position a, the swing arm b (10) automatically resets under the restoring force of the lateral return spring (23); Repeat "Step 2" to "Step 5" 360 times.

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