A gripper, robot and method for loading and unloading drill pipe joints

Abstract

The present application relates to a gripper, a robot and a method for loading and unloading drill pipe joints. The present application can compensate for the problem of inaccurate positioning of the robot gripper, which may easily cause misalignment or defective products, sense the spatial posture of the joint, and automatically adjust the feeding position; by setting three groups of laser ranging sensors to measure the compression of the pull rod, a plane principle can be determined using three non-collinear points, and the deflection angle of the drill pipe joint on the robot gripper can be calculated; according to the deflection angle, the Y-axis and Z-axis of the truss robot are used to perform radial position compensation to ensure that the workpiece can adaptively enter the machine tool chuck; in addition, the present application can sense whether there are iron filings on the chuck, and can detect whether the workpiece placement position meets the requirements, thereby ensuring that the end face of the drill pipe joint and the bottom surface of the machine tool chuck can fit tightly, avoiding the generation of waste and damage to the tool and machine tool.

Description

Technical Field

[0001] The present application relates to the technical field of automated loading and unloading in machine tool processing, and in particular to a gripper, a robot and a method for loading and unloading drill pipe joints. Background Art

[0002] Drill pipe consists of a tubular body connected to joints at each end. Its purpose is to transport drilling mud to the drill bit. Drill pipe joints are primarily circular in shape, and each joint features an internal hole to facilitate the passage of drilling mud. Drill pipe joints are typically machined by turning, using a manual or hydraulic three-jaw chuck as the fixture on the lathe. The end face and outer cylindrical surface are turned in a single clamping operation.

[0003] The production process for drill tool joints typically requires manual loading and unloading, a labor-intensive process that relies heavily on manual labor. With increasing industrial automation, the combination of hydraulic chucks and robots for loading and unloading has emerged to reduce labor intensity and enhance intelligent factory operations. During automated loading, a single robot often supports multiple machine tools, each with its own chuck positions. The robot must be flexible enough to accommodate these diverse machine tools. Hydraulic chucks generally have a smaller stroke than manual chucks, resulting in limited clearance between the joint and the chuck during automated loading of drill tool joints. This is particularly true for larger joints with an outer diameter close to the gripping stroke of a machine tool's three-jaw chuck. Furthermore, the robot is prone to misalignment of the joint, causing the joint's position to deviate from its initial, pre-trained position during loading. This can prevent the joint from entering the chuck smoothly, leading to loading failures.

[0004] In addition, during the automatic loading process, if the long iron chips on the chuck are not automatically cleaned or the feeding position is not in place, the processing reference surface of the drill pipe joint will be difficult to meet the requirements, and automatic processing will produce waste. In serious cases, it will also damage the tool and machine tool, affecting the automatic processing process of the drill pipe joint. Summary of the Invention

[0005] In order to overcome at least one deficiency in the prior art, the present application provides a gripper, a robot and a method for loading and unloading drill pipe joints.

[0006] In a first aspect, a gripper for loading and unloading drill pipe joints is provided, comprising: a robot gripper Y-axis drive module, a manipulator first rotation module, a manipulator second rotation module, and a plurality of manipulator execution end modules;

[0007] The robot gripper Y-direction drive module is connected to the first rotation module of the manipulator, and can drive the first rotation module of the manipulator to move linearly along the Y direction of the robot truss;

[0008] The first rotating module of the manipulator is connected to the second rotating module of the manipulator via a first rotating shaft. When the first rotating shaft rotates, it can drive the second rotating module of the manipulator to rotate along a circumferential direction perpendicular to the axis of the first rotating shaft.

[0009] The second rotating module of the manipulator is connected to multiple manipulator execution end modules through the second rotating shaft. When the second rotating shaft rotates, it can drive the multiple manipulator execution end modules to rotate along the circumferential direction perpendicular to the axis of the second rotating shaft.

[0010] In one embodiment, the Y-axis drive module of the robot gripper includes: a truss Z-axis fixed plate, a servo motor, a ball screw reducer and a slide rail. The servo motor, the ball screw reducer and the slide rail are all installed on the truss Z-axis fixed plate. The servo motor drives the ball screw reducer to drive the first rotation module of the robot arm to move along the slide rail.

[0011] In one embodiment, the first rotation module of the manipulator includes: a first bracket of the manipulator, a first swing cylinder and a first rotation axis; the first swing cylinder is fixed on the first bracket of the manipulator, and when compressed air is connected, the first swing cylinder drives the first rotation axis to rotate synchronously; the first rotation axis is fixedly connected to the Z axis of the robot truss and the second rotation module of the manipulator, and the axis of the first rotation axis is parallel to the Z axis of the robot truss.

[0012] In one embodiment, the second rotation module of the manipulator includes: a second bracket of the manipulator, a second swing cylinder and a second rotation axis; the second swing cylinder is fixedly connected to the second bracket of the manipulator, and the second rotation axis is fixedly connected to multiple manipulator execution end modules; when compressed air is connected, the second swing cylinder drives the second rotation axis to rotate synchronously, thereby driving multiple manipulator execution end modules to rotate.

[0013] In one embodiment, each manipulator performs an end module, comprising: a three-jaw pneumatic chuck, a plurality of adjustment blocks, a plurality of clamping jaws, a buffer plate, a plurality of cylindrical springs, a plurality of pull rods, a sensor fixing bracket, a plurality of laser ranging sensors, and an air gripper inlet / outlet;

[0014] A plurality of adjustment blocks are connected to the three-jaw pneumatic chuck and a plurality of clamping jaws, and the relative positions of the three-jaw pneumatic chuck and the clamping jaws are adjusted by adjusting the installation positions of the adjustment blocks and the clamping jaws;

[0015] The buffer plate is arranged in the internal space formed by multiple clamping claws. One end of each pull rod is connected to the buffer plate, and the other end is connected to the sensor fixing bracket. A cylindrical spring is installed on each pull rod; multiple laser ranging sensors are installed on the sensor fixing bracket to measure the distance between the end of the pull rod and the laser ranging sensor; the three-jaw pneumatic chuck is equipped with air gripper inlet / outlet. When the air gripper inlet / outlet is connected to compressed air, the three-jaw pneumatic chuck drives multiple clamping claws to open or close to loosen or clamp the workpiece.

[0016] In one embodiment, a group of countersunk holes and a group of threaded holes are provided on the adjustment block. The adjustment block is connected to the three-jaw pneumatic chuck through the countersunk holes. The adjustment block is movably connected to the clamping jaws through the threaded holes and the waist-shaped holes of the clamping jaws.

[0017] In one embodiment, the clamping inner and outer facades of each clamping jaw are in a back-to-back V-shape.

[0018] In one embodiment, a first detection switch is provided on the first rotation module of the manipulator, and a second detection switch is provided on the second rotation module of the manipulator.

[0019] In one embodiment, an air blowing pipe is provided on the first rotating module of the manipulator.

[0020] In a second aspect, a robot for loading and unloading drill rod joints is provided, comprising a truss overall structural frame and a gripper for loading and unloading drill rod joints, wherein the gripper for loading and unloading drill rod joints is based on the above-mentioned gripper for loading and unloading drill rod joints.

[0021] In a third aspect, a method for loading and unloading a drill pipe joint is provided, comprising:

[0022] Step 1: teach the robot's initial YZ axis control position to obtain the first truss mechanical position (X0, Y0, Z0) of the teaching point;

[0023] Step 2: teach the initial X-axis control position of the robot, control any manipulator to execute the end module to send the workpiece into the machine chuck, and make the top of the workpiece contact the bottom step of the machine chuck, and determine the second truss mechanical position (X1, Y0, Z0) of the teaching point; the manipulator executes the end module to continue to move along the X-axis of the truss and ensure that the cylindrical spring has a compression amount, and obtain the third truss mechanical position (X1, Y0, Z0) of the teaching point. 11 , Y0, Z0); the distances u1, u2 and u3 between the ends of the three pull rods and the corresponding laser ranging sensors are measured by three laser ranging sensors;

[0024] Step 3: Control the first manipulator to execute the clamping claw of the end module to clamp the unprocessed workpiece. The cylindrical spring has a compression amount. Obtain the workpiece deflection angle θ. When z1 is the maximum, Wherein, z1, z2 and z3 are the distances z1, z2 and z3 between the three ends of the pull rod and the corresponding laser ranging sensors respectively measured by the three laser ranging sensors;

[0025] Step 4: The first rotating axis of the first rotating module of the manipulator rotates and touches the first detection switch, the control system sends a signal, the clamping claw of the second manipulator execution end module remains loosened, and the claw moves to the first truss mechanical position (X0, Y0, Z0); the machine tool chuck rotates, and the air blow pipe blows air to the machine tool chuck to clean the cutting fluid and iron chips on the machine tool chuck; after the blowing is completed, the claw moves to the second truss mechanical position (X1, Y0, Z0), and controls the clamping claw of the second manipulator execution end module to clamp the processed workpiece, and the claw moves to the first truss mechanical position (X0, Y0, Z0); the machine tool chuck rotates, and the air blow pipe blows air to the machine tool chuck to clean the cutting fluid and iron chips on the machine tool chuck; after the blowing is completed, the second rotating axis rotates to drive the first manipulator execution end module to rotate, touching the second detection switch, and the first manipulator execution end module is ready to send the unprocessed workpiece into the machine tool chuck;

[0026] Step 5: Determine whether radial position compensation is required. If so, perform radial position compensation, i.e. control the gripper to move to the truss mechanical position (X0, Y0+δ Y ,Z0+δ Z ), δ Y is the movement distance of the gripper along the Y axis, δ Z is the movement distance of the gripper along the Z axis, execute step 6; if not, control the gripper to move to the first truss mechanical position (X0, Y0, Z0), execute step 7;

[0027] Step 6: Release the machine chuck and control the gripper to move to the truss mechanical position (X1, Y0+δ Y ,Z0+δ Z ), the clamping claw is released; the claw is controlled to move to the truss mechanical position (X 11 ,Y0+δ Y ,Z0+δ Z ) after which the machine chuck is clamped; the gripper is controlled to move to the third truss mechanical position (X 11 , Y0, Z0), the laser distance sensor measures the distances between the three rod ends and the corresponding laser distance sensors as u 11 、u 22 and u 33 , proceed to step 8;

[0028] Step 7: Release the machine chuck, control the claw to move to the second truss mechanical position (X1, Y0, Z0), and release the clamping claw; control the claw to move to the third truss mechanical position (X1, Y0, Z0). 11, Y0, Z0), the machine chuck is clamped; the laser distance sensor measures the distances between the three tie rod ends and the corresponding laser distance sensors are u 11 、u 22 and u 33 , proceed to step 8;

[0029] Step 8: Determine whether the cutting fluid and iron chips on the machine chuck are clean, that is, whether the min{u 11 ,u 22 ,u 33}≤min{u1,u2,u3}-U, where U is the set threshold. If it is satisfied, it means that it is not cleaned up, and manual processing is performed. Then the gripper is controlled to move to the first truss mechanical position (X0,Y0,Z0), and the process returns to step 3 to perform the next operation. If it is not satisfied, it means that it is cleaned up, and the gripper is controlled to move to the first truss mechanical position (X0,Y0,Z0); the process returns to step 3 to perform the next operation.

[0030] In one embodiment, determining whether radial position compensation is required includes:

[0031] like Then radial position compensation is not required, otherwise, radial position compensation is required, where ε is the distance between the farthest edge of the workpiece and the center of the machine chuck, and D is the loose diameter of the machine chuck, in mm;

[0032]

[0033] Where d is the outer diameter of the workpiece in mm, θ is the deflection angle of the workpiece, and L is the length of the workpiece in mm.

[0034] In one embodiment, the method further comprises:

[0035] Calculate the longest straight-line distance δ for position compensation max :

[0036]

[0037] Where d is the outer diameter of the workpiece, in mm, D is the loose diameter of the machine chuck, in mm, L is the length of the workpiece, in mm, θ is the deflection angle of the workpiece, and W is the depth of the machine chuck, in mm;

[0038] δ max Decomposed into the movement distance δ of the gripper along the Y axis Y and the movement distance δ of the gripper along the Z axis Z .

[0039] Compared with the prior art, this application has the following beneficial effects:

[0040] 1. The present application has a high degree of flexibility. A Y-drive module is provided at the end of the truss robot gripper, which not only reduces the installation position accuracy between the truss robot and the machine tool, but also facilitates the adjustment of the loading position of the drill pipe joint; by setting two sets of rotary cylinders, the two sets of rotary cylinders are independently controlled to load and unload the machine tool, which can adapt to different placement methods of the machine tool; a cylindrical spring and a buffer plate are provided at the end of the robotic gripper, which facilitates the correction of the workpiece posture when the robotic gripper clamps the workpiece and reduces the workpiece grasping deviation rate; an adjustment block is provided at the end of the robotic gripper, which can adapt to drill pipe joints of different outer diameter specifications.

[0041] 2. This application can compensate for the problem of inaccurate positioning of the robot gripper, which can easily cause misalignment or defective products. It can sense the spatial position of the joint and automatically adjust the feeding position. By setting up three groups of laser ranging sensors to measure the compression of the pull rod, a plane principle can be determined using three non-collinear points to calculate the deflection angle of the drill rod joint on the robot gripper. According to the deflection angle, the Y-axis and Z-axis of the truss robot are used to perform radial position compensation to ensure that the workpiece can adaptively enter the machine tool chuck.

[0042] 3. This application can sense whether there are iron filings on the chuck and detect whether the workpiece placement meets the requirements, thereby ensuring that the end face of the drill pipe joint and the bottom surface of the machine tool chuck can fit tightly, avoiding waste and damage to the tool and machine tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The present application may be better understood by referring to the following description in conjunction with the accompanying drawings, which together with the following detailed description are incorporated into and form a part of this specification. In the drawings:

[0044] Figure 1 A schematic diagram of a gripper for loading and unloading a drill pipe joint according to an embodiment of the present application is shown;

[0045] Figure 2 A schematic diagram of a manipulator execution end module according to an embodiment of the present application is shown;

[0046] Figure 3 Shows a schematic diagram of the installation structure of the adjustment block and the clamping claw;

[0047] Figure 4 A schematic diagram of a robot for loading and unloading drill pipe joints according to an embodiment of the present application is shown;

[0048] Figure 5 A schematic diagram showing the teaching of the robot's initial YZ axis control position is shown;

[0049] Figure 6 A schematic diagram of the hand feeding the lathe chuck is shown;

[0050] Figure 7It shows a schematic diagram of the interference limit position 1 between the drill pipe joint and the lathe chuck;

[0051] Figure 8 A schematic diagram of the interference limit position 2 between the drill pipe joint and the lathe chuck is shown.

[0052] Reference numerals:

[0053] 1-Lathe; 101-Machine tool chuck; 2-Gripper for loading and unloading drill pipe joints; 21-Robot gripper Y-axis drive module; 211-Truss Z-axis fixing plate; 212-Servo motor; 213-Ball screw reducer; 214-Slide rail; 22-Manipulator first rotation module; 221-Manipulator first bracket; 222-First swing cylinder; 223-First rotation axis; 23-Manipulator second rotation module; 231-Manipulator second bracket; 232-Second swing cylinder; 233-Second rotation axis; 24-Manipulator Execution end module; 241-three-jaw pneumatic chuck; 242-adjustment block; 243-clamping claw; 244-buffer plate; 245-cylindrical spring; 246-pull rod; 247-sensor fixing bracket; 248-laser ranging sensor; 249-air claw inlet / outlet; 25-second detection switch; 26-first detection switch; 27-air blow pipe; 3-truss overall structural frame; 401-drill pipe joint blank; 402-drill pipe joint processed material; 403-point position calibration hole fixture; 404-point position calibration axis fixture. DETAILED DESCRIPTION

[0054] Exemplary embodiments of the present application are described below with reference to the accompanying drawings. For the sake of clarity and conciseness, not all features of actual embodiments are described in this specification. However, it should be understood that in the process of developing any such actual embodiment, many implementation-specific decisions may be made to achieve the developer's specific goals, and these decisions may vary from one implementation to another.

[0055] It is also necessary to explain here that, in order to avoid obscuring the present application due to unnecessary details, the accompanying drawings only show the device structure closely related to the solution according to the present application, while other details that are not closely related to the present application are omitted.

[0056] It should be understood that the present application is not limited to the described embodiments due to the following description with reference to the accompanying drawings. In this document, where feasible, the embodiments may be combined with each other, features between different embodiments may be replaced or borrowed, and one or more features may be omitted in one embodiment.

[0057] The embodiment of the present application provides a gripper 2 for loading and unloading drill pipe joints. Figure 1 A schematic diagram of a gripper for loading and unloading a drill pipe joint according to an embodiment of the present application is shown. Figure 1 , including: a robot gripper Y-direction driving module 21, a manipulator first rotation module 22, a manipulator second rotation module 23, and multiple manipulator execution end modules 24;

[0058] The robot gripper Y-direction driving module 21 is connected to the manipulator first rotation module 22, and can drive the manipulator first rotation module 22 to move linearly along the robot truss Y direction;

[0059] The first rotating module 22 of the manipulator is connected to the second rotating module 23 of the manipulator via the first rotating shaft 223. When the first rotating shaft 223 rotates, it can drive the second rotating module 23 of the manipulator to rotate along a circumferential direction perpendicular to the axis of the first rotating shaft 223.

[0060] The second manipulator rotating module 23 is connected to multiple manipulator execution end modules 24 via the second rotating shaft 233 . When the second rotating shaft 233 rotates, it can drive the multiple manipulator execution end modules 24 to rotate along a circumferential direction perpendicular to the axis of the second rotating shaft 233 .

[0061] In this embodiment, a gripper is mounted on a robot used for loading and unloading drill rod joints. The robot uses the gripper to grasp a workpiece, such as a drill rod joint, thereby achieving the purpose of loading and unloading the workpiece. The provision of a robot gripper Y-axis drive module 21 not only reduces the installation position accuracy between the truss robot and the machine tool, but also facilitates adjustment of the drill rod joint loading position. Furthermore, by providing a manipulator first rotation module 22, a manipulator second rotation module 23, and multiple manipulator execution end modules 24, the two sets of rotation modules are independently controlled to load and unload the machine tool, adapting to different machine tool placement methods.

[0062] In one embodiment, the robot gripper Y-axis drive module 21 includes: a truss Z-axis fixed plate 211, a servo motor 212, a ball screw reducer 213 and a slide rail 214. The servo motor 212, the ball screw reducer 213 and the slide rail 214 are all installed on the truss Z-axis fixed plate 211. The servo motor 212 drives the ball screw reducer 213 to drive the robot arm first rotation module 22 to move along the slide rail 214.

[0063] In one embodiment, the first rotation module 22 of the manipulator includes: a first bracket 221 of the manipulator, a first swing cylinder 222 and a first rotation axis 223; the first swing cylinder 222 is fixed on the first bracket 221 of the manipulator, and when compressed air is connected, the first swing cylinder 222 drives the first rotation axis 223 to rotate synchronously; the first rotation axis 223 is fixedly connected to the Z axis of the robot truss and the second rotation module 23 of the manipulator, and the axis of the first rotation axis 223 is parallel to the Z axis of the robot truss.

[0064] In one embodiment, the manipulator second rotation module 23 includes: a manipulator second bracket 231, a second swing cylinder 232, and a second rotation axis 233; the second swing cylinder 232 is fixedly connected to the manipulator second bracket 231, and the second rotation axis 233 is fixedly connected to multiple manipulator execution end modules 24; when compressed air is supplied, the second swing cylinder 232 drives the second rotation axis 233 to rotate synchronously, thereby driving the rotation of the multiple manipulator execution end modules 24. Here, the multiple manipulator execution end modules 24 can be specifically set to two, namely the first manipulator execution end module and the second manipulator execution end module.

[0065] In one embodiment, Figure 2 A schematic diagram of a manipulator execution end module according to an embodiment of the present application is shown. Figure 2 Each manipulator execution end module 24 includes: a three-jaw pneumatic chuck 241, multiple adjustment blocks 242, multiple clamping claws 243, a buffer plate 244, multiple cylindrical springs 245, multiple pull rods 246, a sensor fixing bracket 247, multiple laser ranging sensors 248 and an air claw inlet / outlet 249;

[0066] A plurality of adjustment blocks 242 are connected to the three-jaw pneumatic chuck 241 and the plurality of clamping jaws 243. The relative positions of the three-jaw pneumatic chuck 241 and the clamping jaws 243 are adjusted by adjusting the installation positions of the adjustment blocks 242 and the clamping jaws 243.

[0067] The buffer plate 244 is arranged in the internal space formed by multiple clamping claws 243, one end of each pull rod 246 is connected to the buffer plate 244, and the other end is connected to the sensor fixing bracket 247, and a cylindrical spring 245 is installed on each pull rod 246; multiple laser ranging sensors 248 are installed on the sensor fixing bracket 247, which are used to measure the distance between the end of the pull rod 246 and the laser ranging sensor 248; the three-jaw pneumatic chuck 241 is installed with an air gripper inlet / outlet 249. When the air gripper inlet / outlet 249 is connected to compressed air, the three-jaw pneumatic chuck 241 drives the multiple clamping claws 243 to open or close to loosen or clamp the workpiece.

[0068] In this embodiment, when clamping jaws 243 grip the outer diameter of a workpiece, three-jaw pneumatic chuck 241 is initially released. A buffer plate 244 contacts the top end face of the workpiece, forcing cylindrical spring 245 to compress a certain distance before clamping. Cylindrical spring 245 and buffer plate 244 work together to provide a buffer, correcting the workpiece's placement on the rack. This improves parallelism between three-jaw pneumatic chuck 241 and the workpiece axis during clamping, reducing workpiece misalignment.

[0069] Furthermore, the sensor mounting bracket 247 is provided with three holes, which are evenly spaced 120° around the axis of the three-jaw pneumatic chuck 241, with clearance fit to the outer diameter of the pull rod 246. The buffer plate 244 is provided with three threaded holes, evenly spaced 120°, with the pitch circle diameter of the three holes equal to the pitch circle diameter of the three holes on the sensor mounting bracket 247. The pull rod 246 is fixedly connected to the buffer plate 244 via threads. When the buffer plate 244 is forced to move, the pull rod 246 also moves. The laser ranging sensor 248 can measure the distance change of the pull rod 246, thereby sensing the relative position of the gripper and the workpiece.

[0070] Optionally, three adjusting blocks 242 and three clamping claws 243 are provided respectively, and three pull rods 246, three cylindrical springs 245, and three laser ranging sensors 248 are provided respectively.

[0071] Specifically, Figure 3 The schematic diagram of the installation structure of the adjustment block and the clamping claw is shown. Figure 3 The adjustment block 242 is provided with a set of countersunk holes and a set of threaded holes. The adjustment block 242 is connected to the three-jaw pneumatic chuck 241 through the countersunk holes. The adjustment block 242 is movably connected to the clamping jaw 243 through the threaded holes and the waist-shaped holes of the clamping jaw 243. Here, the configuration of the adjustment block 242 allows the gripper to adapt to workpieces with different outer diameters.

[0072] In one embodiment, in order to adapt to the situation of clamping the outer circle and inner circle of the workpiece, the inner and outer clamping facades of each clamping jaw 243 are back-to-back V-shaped, and the V-shaped angle is 20°~25°. The clamping surface of the clamping jaw 243 is knurled to increase the friction between the clamping jaw 243 and the workpiece.

[0073] In one embodiment, a first detection switch 26 is provided on the first rotation module 22 of the manipulator, and a second detection switch 25 is provided on the second rotation module 23 of the manipulator.

[0074] In one embodiment, the manipulator first rotating module 22 is provided with an air blowing pipe 27. The air blowing pipe 27 is used to blow air onto the machine chuck 101 or the processed workpiece to clean the cutting fluid and iron chips on the machine chuck 101 and the workpiece.

[0075] The present application also provides a robot for loading and unloading drill pipe joints. Figure 4 A schematic diagram of a robot for loading and unloading drill pipe joints according to an embodiment of the present application is shown. Figure 4 , including a truss overall structural frame 3 and a gripper 2 for loading and unloading drill rod joints. The gripper 2 for loading and unloading drill rod joints is the gripper for loading and unloading drill rod joints described in the previous embodiment.

[0076] The present application also provides a method for loading and unloading a drill pipe joint, comprising:

[0077] Step 1: Teach the initial YZ axis control position of the robot to obtain the first truss mechanical position (X0, Y0, Z0) of the teaching point. Figure 5 A schematic diagram showing the teaching of the robot's initial YZ-axis control position.

[0078] Specifically, see Figure 5 , control any one of the two manipulators to execute the end modules, clamp the point position calibration axis jig 404 through the clamping claws, and manually adjust the position of the point position calibration axis jig 404 on the clamping claws so that the values ​​measured by the three laser ranging sensors 248 remain equal; after the machine tool chuck 101 clamps the point position calibration hole jig 403, manually control the manipulator to execute the end module to realize the hole configuration of the point position calibration axis jig 404 and the point position calibration hole jig 403, such as Figure 5 As shown, the first truss mechanical position (X0, Y0, Z0) of the teaching point is obtained.

[0079] Step 2: teach the initial X-axis control position of the robot, that is, control any manipulator to execute the end module to send the workpiece into the machine tool chuck 101, and make the top of the workpiece contact the bottom step of the machine tool chuck 101, and determine the second truss mechanical position (X1, Y0, Z0) of the teaching point; the manipulator executes the end module to continue to move along the truss X axis and ensure that the cylindrical spring 245 has a compression amount, and obtain the third truss mechanical position (X1, Y0, Z0) of the teaching point. 11 , Y0, Z0); the distances u1, u2 and u3 between the ends of the three pull rods 246 and the corresponding laser ranging sensors 248 are measured by the three laser ranging sensors 248.

[0080] Specifically, any manipulator is controlled to execute the clamping claw of the end module to grasp the workpiece, and the position of the point calibration axis fixture 404 on the clamping claw is manually adjusted so that the values ​​measured by the three laser ranging sensors 248 remain equal; ensure that there is no iron filings remaining on the machine chuck 101, keep the machine chuck 101 loose, and manually control the claw to move to the first truss mechanical position (X0, Y0, Z0). Then, the truss robot is controlled to move the X axis toward the chuck until the clamping claw feeds the workpiece into the machine chuck 101 and the top of the workpiece is about to contact the bottom step of the machine chuck, and the second truss mechanical position (X1, Y0, Z0) of the teaching point is determined;

[0081] Step 3: Control the first manipulator to execute the clamping claw 243 of the end module to clamp the unprocessed workpiece. The cylindrical spring 245 has a compression amount. Obtain the workpiece deflection angle θ. When z1 is the maximum, Wherein, z1, z2 and z3 are the distances between the ends of the three pull rods 246 and the corresponding laser ranging sensors 248 respectively measured by the three laser ranging sensors 248;

[0082] Specifically, Figure 6 A schematic diagram shows a gripper loading a lathe chuck. The first manipulator controls the clamping jaws of the end module to grab an unprocessed workpiece, such as a drill pipe joint blank 401, from the material tray. The clamping jaws remain loose, the buffer plate is in close contact with the end face of the unprocessed workpiece, and after ensuring a certain amount of compression of the cylindrical spring, the clamping jaws clamp the unprocessed workpiece. At this point, due to the clamping jaw's grasping position accuracy and workpiece placement, as well as the fact that the clamping jaws only partially contact the unprocessed workpiece, it is difficult to ensure that the unprocessed workpiece is absolutely clamped by the clamping jaws. A certain deflection angle θ inevitably exists between the workpiece axis and the three clamping jaws. Because the buffer plate 244 is in close contact with the workpiece end face, its tilt direction is consistent with the workpiece. Three non-collinear points can define a plane. The tilt angle of the buffer plate 244 can be fed back through the different positions of the three tie rods 246. The workpiece deflection angle θ is calculated by measuring the distance between the three tie rod ends and the corresponding laser ranging sensors using laser ranging sensors.

[0083] Step 4: The first rotating shaft 223 of the first rotating module 22 of the manipulator rotates and touches the first detection switch 26. The control system sends a signal, and the clamping claw 243 of the second manipulator execution end module remains in a loose state, and the claw moves to the first truss mechanical position (X0, Y0, Z0); the machine tool chuck 101 rotates, and the air blow pipe 27 blows air to the machine tool chuck 101 to clean the cutting fluid and iron chips on the machine tool chuck 101. After the blowing is completed, the claw moves to the second truss mechanical position (X1, Y0, Z0), and the second The clamping claw 243 of the manipulator end module clamps the processed workpiece, such as the drill pipe joint material 402, and the claw moves to the first truss mechanical position (X0, Y0, Z0). The machine chuck 101 rotates, and the air blow pipe 27 blows air into the machine chuck 101 to remove cutting fluid and iron chips from the machine chuck 101. After the air blow is completed, the second rotating shaft 233 rotates, driving the first manipulator end module to rotate, triggering the second detection switch 25. The first manipulator end module is ready to deliver the unprocessed workpiece into the machine chuck 101.

[0084] Step 5: Determine whether radial position compensation is required. If so, perform radial position compensation, i.e. control the gripper to move to the truss mechanical position (X0, Y0+δ Y ,Z0+δ Z ), δ U is the movement distance of the gripper along the Y axis, δ Zis the movement distance of the gripper along the Z axis, execute step 6; if not, control the gripper to move to the first truss mechanical position (X0, Y0, Z0), execute step 7.

[0085] Specifically, determining whether radial position compensation is required may include:

[0086] like Then radial position compensation is not required and the workpiece can smoothly enter the machine chuck 101. Otherwise, radial position compensation is required, that is, the movement of the truss robot's Y-axis and Z-axis is compensated in the opposite direction of the workpiece's deflection direction so that it can smoothly enter the machine chuck 101 and avoid loading failure. Wherein, ε is the distance between the farthest edge of the workpiece and the center of the machine chuck, and D is the loose diameter of the machine chuck, in mm;

[0087] Figure 7 The diagram shows the limit position 1 of the interference between the drill pipe joint and the lathe chuck. When the edge of the workpiece deflects and contacts the edge of the machine chuck, as shown in FIG. Figure 7 As shown, according to Figure 7 , the distance ε between the farthest edge of the workpiece and the center of the machine chuck satisfies the following formula:

[0088]

[0089] Where d is the outer diameter of the workpiece in mm, θ is the deflection angle of the workpiece, and L is the length of the workpiece in mm.

[0090] Figure 8 The diagram shows the limit position 2 of the interference between the drill pipe joint and the lathe chuck. When reverse compensation is performed, the straight line distance of the teaching position compensation should avoid collision and interference between the workpiece and the front end of the machine chuck. The limit position is as follows Figure 8 As shown. According to its geometric position relationship, calculate the farthest straight line distance δ of position compensation max :

[0091]

[0092] Where d is the outer diameter of the workpiece, in mm, D is the loose diameter of the machine chuck, in mm, L is the length of the workpiece, in mm, θ is the deflection angle of the workpiece, and W is the depth of the machine chuck, in mm;

[0093] Then, δ max Decomposed into the movement distance δ of the gripper along the Y axis Y and the movement distance δ of the gripper along the Z axis Z .

[0094] Step 6: Radial position compensation. The machine chuck 101 is released and the gripper is controlled to move to the truss mechanical position (X1, Y0+δ Y ,Z0+δ Z), the clamping claw is released; the claw is controlled to move to the truss mechanical position (X 11 ,Y0+δ Y ,Z0+δ Z ) after which the machine chuck 101 is clamped; the gripper is controlled to move to the third truss mechanical position (X 11 , Y0, Z0), the laser distance sensor 248 measures the distances between the ends of the three pull rods 246 and the corresponding laser distance sensors 248 as u 11 、u 22 and u 33 , proceed to step 8;

[0095] Step 7: The machine chuck 101 is released, the gripper is controlled to move to the second truss mechanical position (X1, Y0, Z0), and the clamping claw is released; the gripper is controlled to move to the third truss mechanical position (X1, Y0, Z0). 11 , Y0, Z0), the machine chuck 101 is clamped; the laser distance sensor 248 measures the distances between the ends of the three pull rods 246 and the corresponding laser distance sensors 248, which are u 11 、u 22 and u 33 , proceed to step 8;

[0096] Step 8: Axial position check. Determine whether the cutting fluid and iron chips on the machine chuck 101 are clean, that is, whether the min{u 11 ,u 22 ,u 33}≤min{u1,u2,u3}-U, U is the set threshold, which can be set to 0.2 according to experience. If it is satisfied, it means that it is not cleaned up, and manual processing is performed, and then the gripper is controlled to move to the first truss mechanical position (X0,Y0,Z0), and the process returns to step 3 to perform the next operation; if it is not satisfied, it means that it is cleaned up, and the gripper is controlled to move to the first truss mechanical position (X0,Y0,Z0); the process returns to step 3 and the next operation is performed to ensure that the workpiece can be placed in the machine tool chuck 101 every time.

[0097] In summary, this application has the following technical effects:

[0098] 1. The present application has a high degree of flexibility. A Y-drive module is provided at the end of the truss robot gripper, which not only reduces the installation position accuracy between the truss robot and the machine tool, but also facilitates the adjustment of the loading position of the drill pipe joint; by setting two sets of rotary cylinders, the two sets of rotary cylinders are independently controlled to load and unload the machine tool, which can adapt to different placement methods of the machine tool; a cylindrical spring and a buffer plate are provided at the end of the robotic gripper, which facilitates the correction of the workpiece posture when the robotic gripper clamps the workpiece and reduces the workpiece grasping deviation rate; an adjustment block is provided at the end of the robotic gripper, which can adapt to drill pipe joints of different outer diameter specifications.

[0099] 2. This application can compensate for the problem of inaccurate positioning of the robot gripper, which can easily cause misalignment or defective products. It can sense the spatial position of the joint and automatically adjust the feeding position. By setting up three groups of laser ranging sensors to measure the compression of the pull rod, a plane principle can be determined using three non-collinear points to calculate the deflection angle of the drill rod joint on the robot gripper. According to the deflection angle, the Y-axis and Z-axis of the truss robot are used to perform radial position compensation to ensure that the workpiece can adaptively enter the machine tool chuck.

[0100] 3. This application can sense whether there are iron filings on the chuck and detect whether the workpiece placement meets the requirements, thereby ensuring that the end face of the drill pipe joint and the bottom surface of the machine tool chuck can fit tightly, avoiding waste and damage to the tool and machine tool.

[0101] The above descriptions are merely examples of various embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any modifications or substitutions that can be readily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for loading and unloading a drill pipe joint, characterized in that: include: Step 1: teach the robot's initial YZ axis control position to obtain the first truss mechanical position (X0, Y0, Z0) of the teaching point; Step 2, teaching the initial X-axis control position of the robot, controlling any manipulator to execute the end module to send the workpiece into the machine tool chuck (101), and making the top of the workpiece contact the bottom step of the machine tool chuck (101), and determining the second truss mechanical position (X1, Y0, Z0) of the teaching point; the manipulator executes the end module to continue to move along the truss X axis and ensure that the cylindrical spring (245) has a compression amount, and obtain the third truss mechanical position (X1, Y0, Z0) of the teaching point. 11 , Y0, Z0); measuring the distances u1, u2 and u3 between the ends of the three pull rods (246) and the corresponding laser distance sensors (248) respectively through the three laser distance sensors (248); Step 3, control the first manipulator to execute the clamping claw (243) of the end module to clamp the unprocessed workpiece, the cylindrical spring (245) has a compression amount, and obtain the workpiece deflection angle θ. When z1 is the maximum, Wherein, z1, z2 and z3 are respectively the distances z1, z2 and z3 between the ends of the three pull rods (246) and the corresponding laser distance sensors (248) measured by the three laser distance sensors (248); Step 4: The first rotating shaft (223) of the first rotating module (22) of the manipulator rotates and touches the first detection switch (26), the control system sends a signal, the clamping claw (243) of the second manipulator execution end module remains in a loose state, and the claw moves to the first truss mechanical position (X0, Y0, Z0); the machine tool chuck (101) rotates, and the air blow pipe (27) blows air to the machine tool chuck (101) to clean the cutting fluid and iron chips on the machine tool chuck (101). After the blowing is completed, the claw moves to the second truss mechanical position (X1, Y0, Z0 ), controlling the clamping claw (243) of the second manipulator execution end module to clamp the processed workpiece, and the claw moves to the first truss mechanical position (X0, Y0, Z0); the machine tool chuck (101) rotates, and the air blowing pipe (27) blows air to the machine tool chuck (101) to clean the cutting fluid and iron chips on the machine tool chuck (101); after the air blowing is completed, the second rotating shaft (233) rotates to drive the first manipulator execution end module to rotate, touching the second detection switch (25), and the first manipulator execution end module is ready to send the unprocessed workpiece into the machine tool chuck (101); Step 5: Determine whether radial position compensation is required. If so, perform radial position compensation, i.e. control the gripper to move to the fourth truss mechanical position (X0, Y0+δ Y ,Z0+δ Z ), δ Y is the movement distance of the gripper along the Y axis, δ Z is the movement distance of the gripper along the Z axis, execute step 6; if not, control the gripper to move to the first truss mechanical position (X0, Y0, Z0), execute step 7; Step 6: Release the machine chuck (101) and control the claw to move to the fifth truss mechanical position (X1, Y0+δ Y ,Z0+δ Z ), the clamping claw is released; the claw is controlled to move to the sixth truss mechanical position (X 11 ,Y0+δ Y ,Z0+δ Z ) after which the machine chuck (101) is clamped; the hand is controlled to move to the third truss mechanical position (X 11 , Y0, Z0), the laser distance sensor (248) measures the distances between the ends of the three pull rods (246) and the corresponding laser distance sensors (248) to be u respectively. 11 、u 22 and u 33 , proceed to step 8; Step 7: The machine chuck (101) is released, the hand is controlled to move to the second truss mechanical position (X1, Y0, Z0), and the clamping claw is released; the hand is controlled to move to the third truss mechanical position (X1, Y0, Z0). 11 , Y0, Z0), the machine chuck (101) is clamped; the laser distance sensor (248) measures the distances between the ends of the three pull rods (246) and the corresponding laser distance sensors (248) to be u respectively. 11 、u 22 and u 33 , proceed to step 8; Step 8, determine whether the cutting fluid and iron chips on the machine tool chuck (101) are cleaned, that is, whether the min{u 11 ,u 22 ,u 33 }≤min{u1,u2,u3}-U, where U is the set threshold. If it is satisfied, it means that it is not cleaned up, and manual processing is performed. Then the gripper is controlled to move to the first truss mechanical position (X0,Y0,Z0), and the process returns to step 3 to perform the next operation. If it is not satisfied, it means that it is cleaned up, and the gripper is controlled to move to the first truss mechanical position (X0,Y0,Z0); the process returns to step 3 to perform the next operation. The method is based on a gripper for loading and unloading drill pipe joints, and the gripper for loading and unloading drill pipe joints comprises: a robot gripper Y-direction drive module (21), a manipulator first rotation module (22), a manipulator second rotation module (23), and a plurality of manipulator execution end modules (24); The robot gripper Y-direction driving module (21) is connected to the manipulator first rotation module (22), and is capable of driving the manipulator first rotation module (22) to move linearly along the robot truss Y direction; The first rotating module (22) of the manipulator is connected to the second rotating module (23) of the manipulator via a first rotating shaft (223), and when the first rotating shaft (223) rotates, it can drive the second rotating module (23) of the manipulator to rotate along a circumferential direction perpendicular to the axis of the first rotating shaft (223); The manipulator second rotation module (23) is connected to the plurality of manipulator execution end modules (24) via a second rotation shaft (233), and when the second rotation shaft (233) rotates, it can drive the plurality of manipulator execution end modules (24) to rotate along a circumferential direction perpendicular to the axis of the second rotation shaft (233); Each of the manipulator execution end modules (24) includes: a three-jaw pneumatic chuck (241), a plurality of adjustment blocks (242), a plurality of clamping claws (243), a buffer plate (244), a plurality of cylindrical springs (245), a plurality of pull rods (246), a sensor fixing bracket (247), a plurality of laser distance measuring sensors (248) and an air claw inlet / outlet (249); The plurality of adjustment blocks (242) are connected to the three-jaw pneumatic chuck (241) and the plurality of clamping jaws (243), and the relative positions of the three-jaw pneumatic chuck (241) and the clamping jaws (243) are adjusted by adjusting the installation positions of the adjustment blocks (242) and the clamping jaws (243); The buffer plate (244) is arranged in the internal space formed by the multiple clamping claws (243), one end of each pull rod (246) is connected to the buffer plate (244), and the other end is connected to the sensor fixing bracket (247), and each pull rod (246) is fitted with a cylindrical spring (245); the multiple laser distance measuring sensors (248) are installed on the sensor fixing bracket (247) for measuring the distance between the end of the pull rod (246) and the laser distance measuring sensor (248); the air claw inlet / outlet (249) is installed on the three-jaw pneumatic chuck (241), and when the air claw inlet / outlet (249) is connected to compressed air, the three-jaw pneumatic chuck (241) drives the multiple clamping claws (243) to open or close to achieve loosening or clamping of the workpiece; The first rotating module (22) of the manipulator is provided with a first detection switch (26), and the second rotating module (23) of the manipulator is provided with a second detection switch (25).

2. The method according to claim 1, wherein Determine whether radial position compensation is required, including: like Then radial position compensation is not required, otherwise, radial position compensation is required, where ε is the distance between the farthest edge of the workpiece and the center of the machine chuck, and D is the loose diameter of the machine chuck, in mm; Where d is the outer diameter of the workpiece in mm, θ is the deflection angle of the workpiece, and L is the length of the workpiece in mm.

3. The method according to claim 1, wherein The method further comprises: Calculate the longest straight-line distance δ for position compensation max : Where d is the outer diameter of the workpiece, in mm, D is the loose diameter of the machine chuck, in mm, L is the length of the workpiece, in mm, θ is the deflection angle of the workpiece, and W is the depth of the machine chuck, in mm; δ max Decomposed into the movement distance δ of the gripper along the Y axis Y and the movement distance δ of the gripper along the Z axis Z .

4. The method according to claim 1, wherein The robot gripper Y-direction drive module (21) comprises: a truss Z-axis fixed plate (211), a servo motor (212), a ball screw reducer (213) and a slide rail (214); the servo motor (212), the ball screw reducer (213) and the slide rail (214) are all mounted on the truss Z-axis fixed plate (211); the servo motor (212) drives the ball screw reducer (213) to drive the robot arm first rotation module (22) to move along the slide rail (214).

5. The method according to claim 1, wherein The manipulator first rotation module (22) comprises: a manipulator first bracket (221), a first swing cylinder (222) and a first rotation axis (223); the first swing cylinder (222) is fixed on the manipulator first bracket (221); when compressed air is connected, the first swing cylinder (222) drives the first rotation axis (223) to rotate synchronously; the first rotation axis (223) is fixedly connected to the robot truss Z axis and the manipulator second rotation module (23), and the axis of the first rotation axis (223) is parallel to the robot truss Z axis.

6. The method according to claim 1, wherein The manipulator second rotation module (23) comprises: a manipulator second bracket (231), a second swing cylinder (232) and a second rotation axis (233); the second swing cylinder (232) is fixedly connected to the manipulator second bracket (231), and the second rotation axis (233) is fixedly connected to the multiple manipulator execution end modules (24); when compressed air is connected, the second swing cylinder (232) drives the second rotation axis (233) to rotate synchronously, thereby driving the multiple manipulator execution end modules (24) to rotate.

7. The method according to claim 1, wherein The adjustment block (242) is provided with a group of countersunk holes and a group of threaded holes. The adjustment block (242) is connected to the three-jaw pneumatic chuck (241) through the countersunk holes. The adjustment block (242) is movably connected to the clamping jaw (243) through the threaded holes and the waist-shaped holes of the clamping jaw (243).

8. The method according to claim 1, wherein The inner and outer clamping surfaces of each clamping claw (243) are in a back-to-back V-shape.

9. The method according to claim 1, wherein An air blowing pipe (27) is provided on the first rotating module (22) of the manipulator.

10. A robot for loading and unloading drill pipe joints, characterized in that: It comprises a truss integral structural frame (3) and a gripper (2) for loading and unloading drill rod joints, wherein the gripper (2) for loading and unloading drill rod joints is used to implement the method described in any one of claims 1 to 9.

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