Automatic surfacing device for steel PDC drill bit

Abstract

The invention discloses an automatic surfacing device for a steel PDC drill bit. A welding robot and a two-axis positioner of the robot system are integrated through a servo bus to form an eight-degree-of-freedom system, and control over the motion trails of a welding gun and a drill bit of steel body PDC drill bit surfacing is completed; the robot system and the welding system control the welding current and the wire feeding speed through analog quantity communication, and specification parameters of a welding drill bit are set on an upper computer; the arc voltage tracking system monitors and controls the arc height in real time through an arc voltage adjusting mechanism; the measurement control system collects parameters in the surfacing process and monitors the surfacing operation process in real time. The automatic surfacing device has the beneficial effects that the design is reasonable, the automatic surfacing requirements of drill bits of different specifications can be met, the production efficiency is improved, the consistency of the quality of surfacing layers of products is ensured, the intelligent and digital development of PDC drill bit manufacturing is promoted, and safe production is realized.

Description

Technical Field

[0001] The present invention relates to a surfacing device, in particular to an automatic surfacing device for a steel body PDC bit, belonging to the technical field of oil and gas drilling and development. Background Art

[0002] As the part of the drill string system that directly contacts the formation, the surface performance of the bit directly affects the drilling quality. The body material of the steel body PDC bit is 35CrMo or 42CrMo, and its wear resistance and erosion resistance cannot meet the drilling requirements. Surface hardening is a powerful measure to improve the strength of the steel body PDC bit, and the quality of the wear-resistant layer directly affects the service life of the steel body bit. Surfacing, as a fast and economical process method for material surface modification, can significantly improve the performance and service life of the PDC bit, reduce the use cost, and plays an important role in improving the surface hardening of the steel body PDC bit.

[0003] At present, the surface hardening of the steel body PDC bit basically adopts the nickel-based tungsten carbide flexible wire + oxyacetylene flame surfacing process. The oxyacetylene flame has a lower temperature, can obtain a low dilution rate (1% - 10%) and a thin surfacing layer, has little tungsten carbide burn-off while achieving metallurgical bonding, has a good surface hardening effect, and has a lower equipment cost and flexible operation. However, this process has deficiencies such as high labor cost, large labor intensity, low production efficiency, high dependence of surfacing quality on personnel skills, etc., as well as safety risks. Summary of the Invention

[0004] In order to overcome the deficiencies of high labor cost, large labor intensity, low production efficiency, unstable surfacing quality, and safety risks existing in the existing surface hardening process of the steel body PDC bit, the present invention provides an automatic surfacing device for a steel body PDC bit.

[0005] The technical solution adopted by the present invention to solve its technical problems is: an automatic surfacing device for a steel body PDC bit, in which the welding robot of the robot system and the two-axis positioner are integrated through a servo bus to form an eight-degree-of-freedom system to complete the control of the movement trajectories of the welding torch and the bit for surfacing the steel body PDC bit; the robot system and the welding system control the welding current and wire feeding speed through analog communication, and set the welding bit specification parameters on the upper computer; the arc voltage tracking system monitors and controls the arc height in real time through the arc voltage adjustment mechanism; the measurement and control system collects the surfacing process parameters and monitors the surfacing operation process in real time.

[0006] The arc voltage adjustment mechanism is installed on the end flange of the welding robot.

[0007] A water-cooled argon arc welding torch and a torch anti-collision device are installed on the end flange of the welding robot.

[0008] A distance detection sensor is installed on the end flange of the welding robot.

[0009] The two-axis positioner is installed with a three-jaw self-centering chuck, and the loading balance crane grabs the drill bit and installs it on the three-jaw self-centering chuck.

[0010] The arc voltage tracking system controls the arc height by the arc voltage adjustment mechanism controlled by the PLC set in the control cabinet according to a predetermined adjustment algorithm.

[0011] The measurement and control system collects the surfacing process parameters, monitors the surfacing operation process in real time, and the surfacing process parameters are displayed on the remote control host computer.

[0012] The surfacing process parameters collected by the measurement and control system include: cooling water temperature, water pressure, shielding gas flow rate, welding current, arc voltage.

[0013] The protection system of the automatic surfacing device includes a protection fence, a protection door, and a remote control host computer. The protection fence, the protection door, and the remote control host computer form a closed-loop fence, and the robot system, the welding system, the arc voltage tracking system, and the measurement and control system are arranged inside the closed-loop fence.

[0014] Furthermore, the welding robot is a six-axis welding robot.

[0015] The beneficial effects of the present invention are as follows: reasonable design, capable of meeting the automatic surfacing requirements of drill bits of different specifications, improving production efficiency, ensuring the consistency of the surfacing layer quality of products, promoting the development of PDC drill bit manufacturing towards the direction of intelligence and digitization, and realizing safe production. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the automatic surfacing device for steel body PDC drill bits of the present invention.

[0017] In the figure: 1. Welding robot, 2. Robot controller, 3. Two-axis positioner, 4. Three-jaw self-centering chuck, 5-1. Water-cooled argon arc welding torch, 5-2. Welding torch anti-collision device, 6. Wire feeding system, 7. Argon arc welding power supply, 8. Water-cooling box and gas supply system, 9. Loading balance crane, 10. Arc voltage adjustment mechanism, 11. Control cabinet, 12. Host computer, 13. Protection fence, 14. Protection door, 15. Remote control host computer, 16. Arc voltage sensor, 100. Robot system, 200. Welding system, 300. Arc voltage tracking system, 400. Measurement and control system, 500. Protection system. Detailed Embodiments

[0018] The present invention will be further described below with reference to the drawings and embodiments. However, those skilled in the art should know that the present invention is not limited to the specific embodiments listed, and as long as it conforms to the spirit of the present invention, it should be included within the protection scope of the present invention.

[0019] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "vertical", "upper", "lower", "left", "right", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing or simplifying the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0020] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "linked" should be understood in a broad sense. For example, the connection can be a fixed connection, a detachable connection, a direct connection, an indirect connection, or an integral connection; it can be a mechanical connection, indirectly connected through an intermediate medium, or the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] See the attached Figure 1 An automatic surfacing device for a steel body PDC bit of the present invention includes: a robot system 100, a welding system 200, an arc voltage tracking system 300, a measurement and control system 400, and a protection system 500.

[0022] The welding robot 1 of the robot system 100 and the two-axis positioner 3 are integrated through a servo bus to form an eight-degree-of-freedom system, which completes the control of the movement trajectories of the welding torch and the bit for surfacing the steel body PDC bit; the robot system 100 and the welding system 200 control the welding current and wire feeding speed through analog communication, and set the welding bit specification parameters on the host computer 12; the arc voltage tracking system 300 monitors and controls the arc height in real time through the arc voltage adjustment mechanism 10; the measurement and control system 400 collects the surfacing process parameters and monitors the surfacing operation process in real time.

[0023] The robot system 100 includes a welding robot 1, a robot controller 2, a two-axis positioner 3, a three-jaw self-centering chuck 4, and a loading balance crane 9. The welding robot 1 of the robot system 100 is a six-axis welding robot.

[0024] The two-axis positioner 3 of the robot system 100 is equipped with a three-jaw self-centering chuck 4, and the loading balance crane 9 grabs the bit to the three-jaw self-centering chuck 4 to achieve stable clamping of the bit.

[0025] The welding system 200 includes a water-cooled argon arc welding torch 5-1, a wire feeding system 6, an argon arc welding power source 7, a water-cooled box, and a gas supply system 8. The water-cooled argon arc welding torch 5-1 and the welding torch anti-collision device 5-2 are installed on the end flange of the welding robot 1; a distance detection sensor for measuring the distance from the welding torch to the surface of the bit is installed on the end flange.

[0026] The arc voltage tracking system 300 includes an arc voltage adjustment mechanism 10 and an arc voltage sensor 16. The arc voltage adjustment mechanism 10 is installed on the end flange of the welding robot 1, and the arc voltage sensor 16 is installed in the control cabinet 11 to collect the actual output arc voltage of the welding machine.

[0027] The arc voltage tracking system 300 is controlled by a PLC programmable controller installed in the control cabinet 11 according to a predetermined adjustment algorithm to control the arc voltage adjustment mechanism 10 to control the arc voltage of the electric arc, thereby ensuring the stability of the arc height.

[0028] The measurement and control system 400 includes a control cabinet 11, a host computer 12, and measurement and acquisition sensors. The measurement and acquisition sensors are arranged in the control cabinet 11. The measurement and control system 400 collects the surfacing process parameters, and the collected surfacing process parameters include: cooling water temperature, water pressure, shielding gas flow rate, welding current, arc voltage, etc., and monitors the surfacing operation process in real time. The surfacing process parameters are displayed on the remote control host computer 15, and an alarm is given in time when abnormal data appears.

[0029] The safety protection system 500 includes: a protective fence 13, a protective door 14, and a remote control host computer 15. The protective fence 13, the protective door 14, and the remote control host computer 15 form a closed-loop fence, and the robot system 100, the welding system 200, the arc voltage tracking system 300, and the measurement and control system 400 are arranged inside the closed-loop fence. A semi-transparent arc-proof light-shielding plate is installed on the upper part of the protective fence 13 to prevent the pollution of the surfacing arc light.

[0030] After the robot system 100 identifies and locates the specification of the drill bit to be surfaced, the welding robot 1 cooperates with the two-axis turntable 3, performs spatial trajectory fitting according to the welding process requirements and the feedback of the arc tracking module, controls the movement of the welding robot 1, and controls the welding power supply according to the set welding process at the same time; at the same time, an offline simulation programming software is installed on the host computer of the measurement and control system 400, which is used for offline trajectory planning, simulation operation and offline programming during the welding process.

[0031] The present invention further includes a communication system, wherein: the control cabinet 11 of the welding robot 1 transmits the monitoring signal of the welding process to the robot controller 2; the control cabinet 11 communicates with the welding robot 1 and the two-axis turntable 3 for position and function; the control cabinet 11 and the argon arc welding power supply 7 perform welding control and feedback communication.

[0032] The processing process of applying the automatic surfacing device for steel body PDC drill bits of the present invention is as follows:

[0033] First, the operator uses the loading balance crane 9 to clamp the drill bit to be surfaced on the three-jaw self-centering chuck 4, and then selects the positioning program corresponding to the specification of the drill bit on the host computer of the control system 400 and issues it to start the drill bit positioning program.

[0034] The distance detection sensor on the water-cooled argon arc welding torch 5-1 driven by the robot measures the characteristic values of the tool setting points reserved on the drill bit, completes the angle positioning and fixation of the drill bit, and assists in measuring the machining error of the drill bit.

[0035] After completing the positioning of the drill bit, close the protective door 14, select the surfacing operation program for this specification drill bit on the remote control host computer 15, and start the surfacing operation program when all the status detection signals of the control system are normal.

[0036] Start the surfacing operation. The welding robot 1 drives the welding torch, and at the same time, the two-axis positioner 3 flips to the set angle and performs the surfacing operation according to the predetermined machining path. The welding robot 1 controls the external axis rotation and flipping of the two-axis positioner 3 through the bus according to the program, controls the wire feeder of the wire feeding system 6 to stably feed the flux-cored wire according to the preset welding process through the analog module, and controls the argon arc welding power source 7 to adjust the welding current in real time.

[0037] The welding trajectory program during surfacing is generated by the offline programming software according to the standard model of the drill bit. During actual operation, to overcome the machining error of the drill bit, by collecting the real-time data of the arc voltage in the argon arc welding power source 7 and according to the preset algorithm, control the arc voltage adjustment mechanism 10 to drive the water-cooled argon arc welding torch 5-1 to stretch and retract, realizing the stable control of the arc, so as to ensure the quality of the surfacing weld.

[0038] During the surfacing operation process, when abnormal conditions occur in the surfacing process parameters such as the cooling water temperature, water pressure, shielding gas flow rate, welding current, and arc voltage, they will be displayed, recorded, and given an audible and visual alarm on the remote control host computer 15, prompting the operator to open the protective door 14 to maintain the relevant systems.

[0039] Applying the present invention can completely replace the existing surfacing process of manual oxyacetylene + flexible welding wire by operators, effectively solve the problems of high labor cost, large labor intensity, low production efficiency, unstable surfacing quality, and safety risks in the existing process, and realize the automation of the surfacing on the drill bit surface. The PDC drill bit surfacing robot has the functions of drill bit error recognition and manual / automatic correction, with a positioning accuracy of <0.2 mm; the positioner can bear a weight of 800 kg, and the workpiece size is 100 - 670 mm; the machining angle: 360° circumferentially, -30° to 90° axially, which can meet the automatic surfacing operations of all specification drill bits, and the production efficiency and the consistency of the surfacing layer quality are greatly improved.

[0040] It should be noted that the above embodiments are examples and do not limit the present invention. Those skilled in the art will be able to design many alternative embodiments without departing from the scope of the claims of this patent.

Claims

1. An automatic surfacing device for steel PDC drill bits, characterized by: The welding robot and two-axis positioner of the robot system are integrated through the servo bus to form an eight-degree-of-freedom system, which completes the motion trajectory control of the welding gun and drill bit for steel PDC drill bit cladding. The robot system and the welding system control the welding current and wire feeding speed through analog communication, and set the specification parameters of the welding drill bit on the host computer. The arc voltage tracking system monitors and controls the arc height in real time through the arc voltage adjustment mechanism. The measurement and control system collects the cladding process parameters and monitors the cladding operation process in real time.

2. The automatic surfacing device for steel PDC drill bits according to claim 1 is characterized in that: The arc voltage adjustment mechanism is installed on the end flange of the welding robot.

3. The automatic surfacing device for steel PDC drill bits according to claim 2 is characterized in that: A water-cooled argon arc welding gun and a welding gun anti-collision device are installed on the end flange of the welding robot.

4. The automatic surfacing device for steel PDC drill bits according to claim 3 is characterized by: A distance detection sensor is installed on the end flange of the welding robot.

5. The automatic surfacing welding device for steel PDC drill bits according to any one of claims 1 to 4, characterized in that: The welding robot is a six-axis welding robot.

6. The automatic surfacing device for steel PDC drill bits according to claim 1 is characterized by: The two-axis positioner is equipped with a three-jaw self-centering chuck, and the loading balance crane grabs the drill bit and clamps it in the three-jaw self-centering chuck.

7. The automatic surfacing device for steel PDC drill bits according to claim 1 is characterized by: The arc voltage tracking system is controlled by a PLC arranged in a control cabinet to control the arc voltage adjustment mechanism according to a predetermined adjustment algorithm to control the arc height.

8. The automatic surfacing device for steel PDC drill bits according to claim 1 is characterized by: The measurement and control system collects the surfacing process parameters, monitors the surfacing operation process in real time, and the surfacing process parameters are displayed on the remote control host computer.

9. The automatic surfacing device for steel PDC drill bits according to claim 8 is characterized by: The surfacing welding process parameters collected by the measurement and control system include: cooling water temperature, water pressure, shielding gas flow, welding current, and arc pressure.

10. The automatic surfacing device for steel PDC drill bits according to claim 1 is characterized by: The protection system of the automatic surfacing device includes a protection fence, a protection door, and a remote control host computer. The protection fence, the protection door, and the remote control host computer form a closed-loop fence. The robot system, the welding system, the arc voltage tracking system, and the measurement and control system are arranged in the closed-loop fence.

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