A double-head polishing tool

Abstract

The present application relates to the field of weld polishing, and discloses a double-head polishing tool, which comprises a mounting bracket, a double-head unit, a positioning unit and a locking unit; the double-head unit is arranged on the mounting bracket; the double-head unit comprises a mechanical support assembly arranged on the mounting bracket and used for providing movement limiting and pressure bearing; the mechanical support assembly comprises a connecting flange arranged on the mounting bracket; a control assembly is arranged on the mechanical support assembly; a sand belt polishing assembly is arranged on the control assembly; the positioning unit is arranged on the double-head unit; and the locking unit is arranged on the positioning unit. The product position and the polishing position are accurately identified by means of a point laser scanner and a front-end line laser scanner, and the polishing residual height data is fed back in real time; each polishing head of the sand belt polishing assembly can work independently, and the replacement of the connecting flange can enable the polishing tool to be connected to various specifications of industrial robots, so that the polishing tool is convenient and fast to use and has good versatility.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the technical field of weld grinding, and particularly to a dual-head grinding tool. Background Technology

[0002] With the development of industrial automation, robotic grinding, as an automation technology, has been widely used. Grinding tools are mounted on robotic arms and grind products to a specified height according to a predetermined path. Due to differences in product characteristics and height, conventional grinding tools are difficult to meet the grinding process requirements. As industrialization develops, the demand for straight seam steel pipes is becoming increasingly strong. Therefore, a mature and efficient straight seam steel pipe weld grinding process is particularly important. The quality of the weld after grinding directly determines the pressure resistance and lifespan of the steel pipe. Therefore, the precision and efficiency of robotic grinding of steel pipes urgently need to be improved.

[0003] Patent CN111644944A discloses a dual-grinding head full weld seam grinding equipment and method for pipelines. The equipment includes a machine tool body, a grinding head mechanism, a dust collection mechanism, a pneumatic system, a laser tracking system, an electrical control system, and a workpiece feeding system. During operation, the workpiece feeding system transports the workpiece to the bottom of the machine tool body. The initial position of the grinding head mechanism and the workpiece is adjusted by a small column lifting mechanism. The laser tracking system continuously measures the weld seam appearance morphology data of the workpiece. The electrical control system plans the weld seam grinding motion trajectory based on the weld seam appearance morphology data. The grinding head mechanism performs fully automatic grinding operations on the weld seam on the workpiece surface. The dust collection mechanism adsorbs the dust and particles generated by the grinding head mechanism.

[0004] The existing technology has the following drawbacks:

[0005] 1. The device in this invention relies on a matching machine tool body. In other words, it is not adaptable to a variety of processing environments or multiple mounting devices, which limits its expandability and is not conducive to use in environments where such a machine tool is not available. Therefore, there is a need for an industrial robot device that can connect to multiple mounting devices through an expansion mechanism, such as an industrial robot with or without a flexible arm.

[0006] 2. In this invention, the method for locating the weld seam relies on a laser tracking system. In actual production, since lasers cannot penetrate opaque materials, relying solely on a laser tracking system may result in laser obstruction, causing grinding errors. Therefore, a device that can be positioned mechanically without replacing or removing parts to adapt to different pipe diameters is needed, so that even if the laser is obstructed or other problems occur, the positioning will not be affected, thus preventing errors in weld seam grinding.

[0007] 3. This invention does not mention the locking effect after positioning during the polishing process. In other words, how to keep the positioning position unchanged during the polishing process, and how to withstand the pressure without causing displacement, are points that must be paid attention to in the actual polishing process. Therefore, a device is needed to cooperate with the positioning device and maintain the positioning effect in the actual polishing process to ensure the polishing quality and continuity. Summary of the Invention

[0008] In view of the problems of existing technology, such as not being able to adapt to various mounting devices, not having mechanical positioning and automatically adapting to various pipe diameters, and not being able to maintain mechanical positioning during the grinding process, a dual-grinding head grinding tool is proposed.

[0009] One aspect of this application provides a dual-head grinding tool, the purpose of which is to: adapt to various mounting devices, employ mechanical positioning and adapt to various pipe diameters, and maintain positioning effectiveness during the grinding process.

[0010] A dual-grinding-head grinding tool includes a mounting bracket, a dual-grinding-head unit, a positioning unit, and a locking unit;

[0011] The dual-grinding-head unit is mounted on a bracket and is used to connect with the robotic arm to support the entire device and provide limits.

[0012] The dual-grinding head unit includes: a mechanical support assembly mounted on a mounting bracket for providing motion limiting and pressure bearing; the mechanical support assembly includes a connecting flange mounted on the mounting bracket, a floating tool mounting base mounted at the bottom of the mounting bracket, a scanner mounting base mounted at the bottom of the floating tool mounting base, and a near-end dust collection device mounted at the bottom of the mounting bracket.

[0013] A control component, mounted on the mechanical support assembly, is used to provide motion control during the workflow;

[0014] A belt abrasive grinding assembly, mounted on the control assembly, is used for grinding weld seams;

[0015] The positioning unit is mounted on the dual-grinding head unit and is used to position the weld before and after grinding.

[0016] The locking unit is located on the positioning unit and is used to lock the weld after the positioning unit positions the weld to prevent slippage.

[0017] By adopting the above technical solution, various mechanisms are fixedly installed on the arm of an industrial robot through mechanical support components and work in conjunction with some external systems, making the grinding of welds more efficient, accurately controlling the weld reinforcement height, meeting the processing requirements, reducing costs and increasing efficiency, and simultaneously collecting dust to reduce pollution to the surrounding environment.

[0018] Furthermore, the control component includes an air-floating mechanism mounted on the floating tool mounting base, a swing mechanism mounted on the air-floating mechanism, a front-end line laser scanner mounted on the scanner mounting base, a rear-end line laser scanner mounted on the scanner mounting base, and a point laser scanner mounted on the front-end line laser scanner.

[0019] Using the above technical solution, the air-floating mechanism supports the entire belt sanding assembly and provides freedom of movement up and down. The swing mechanism allows the belt sanding assembly to swing within a certain range, which can adapt to the weld position and precisely control the height. The front-end line laser scanner and the rear-end line laser scanner feed the scanning results back to the control system to precisely control the sanding path and sanding depth.

[0020] Furthermore, the belt sanding assembly includes a base plate disposed on the swing mechanism, a servo motor disposed on the base plate, a drive wheel disposed on the servo motor, a tensioning mechanism disposed on the base plate, an anti-deviation limiting wheel disposed on the base plate, a wrap-around limiting wheel disposed on the base plate, a contact wheel disposed on the base plate, and limiting plates disposed on both sides of the contact wheel.

[0021] Using the above technical solution, the sanding belt is driven by a servo motor, the tensioning mechanism tensions the sanding belt, the anti-deviation limiting wheel fixes the sanding belt in a suitable position, the corner limiting wheel extends the service life of the sanding belt, the contact wheel keeps the sanding belt tightly against the weld surface for grinding, and the limiting plate controls the weld height, ensuring that the weld is 1.5mm high, which meets the process requirements.

[0022] Furthermore, the positioning unit includes a telescopic component, which is disposed on the belt sanding component to provide support force when controlling the weld height;

[0023] The telescopic assembly includes a contact mounting seat disposed on the outside of the contact wheel, a first rotating groove formed on the contact mounting seat, first hinge seats disposed on both sides of the contact mounting seat, a first hydraulic rod disposed on the first hinge seat, a first oil port disposed on the first hydraulic rod, a second hydraulic rod disposed inside the first hydraulic rod, a shaft hole disposed at the end of the second hydraulic rod, a hose disposed on the first oil port, an electromagnetic reversing valve disposed at the end of the hose, and a second oil port disposed on the electromagnetic reversing valve;

[0024] A fixing component, mounted on the telescopic component, is used for adaptive positioning at a specific location on the straight seam steel pipe.

[0025] Using the above technical solution, when using the limiting plate for positioning, it is necessary to replace the limiting plate to adapt to straight seam steel pipes of different diameters. The first hydraulic rod and the second hydraulic rod provide pressure and form a four-bar linkage to directly complete the positioning, saving time and effort, eliminating the need for disassembly and replacement, reducing operation steps and labor costs, and improving operation efficiency.

[0026] Furthermore, the fixing assembly includes a pin seat block disposed on the contact mounting base, a second rotating groove formed on the pin seat block, a pull ring pin disposed in the second rotating groove, a limiting rod disposed on the rotating pin, a first protrusion disposed on the limiting rod, a second protrusion disposed on the limiting rod, a second hinge seat disposed at the end of the limiting rod, a third hinge seat disposed on one side of the second hinge seat, a positioning block disposed on the second hinge seat, elastic members disposed on both sides of the positioning block, a universal wheel disposed in the middle of the positioning block, and a second pull ring pin disposed on the contact mounting base.

[0027] Using the above technical solution, the first and second rotating grooves between the pin seat block and the contact mounting seat together form the pin hole of the pull ring pin. The first and second hydraulic rods apply pressure to the positioning block, while one end of the elastic element abuts against the outer wall of the steel pipe, and the other end applies a reverse thrust to the positioning block. Under the action of the two forces, the universal wheel and the cross-section of the steel pipe are radially collinear, so as to achieve the positioning purpose.

[0028] Furthermore, the locking unit includes a transmission component disposed on the fixing component, used to transmit the movement of the fixing component.

[0029] The transmission assembly includes an active block disposed on a positioning block, a first rotating block disposed on the active block, a hydraulic short rod disposed on the rotating block, a piston disposed on the hydraulic short rod, a hydraulic cylinder disposed outside the piston, a transmission pipe disposed on the outer wall of the hydraulic cylinder, a second rotating block disposed at the end of the hydraulic cylinder, and a passive block disposed on a third hinge seat.

[0030] A trigger assembly, mounted on the transmission assembly, is used to lock the movement of the transmission assembly.

[0031] Using the above technical solution, the active block moves along with the positioning block, allowing the hydraulic short rod to move flexibly within the hydraulic cylinder. This converts the movement of the positioning block into the movement of the hydraulic oil in the transmission pipe, facilitating the limitation and control of the positioning block's movement, and enabling the locking of the movement when necessary to prevent adverse effects on the weld grinding work caused by the movement of the positioning block.

[0032] Furthermore, the trigger assembly includes a frame mounted on the pin block, a communication oil pipe mounted on the frame, a sealing plug disposed within the communication oil pipe, a rotating shaft disposed at the end of the frame, a pawl disposed on the rotating shaft, a latch disposed at one end of the pawl, a radial wheel disposed at the other end of the pawl, a shut-off valve body mounted on the frame, a valve core disposed within the shut-off valve body, and a spring disposed within the shut-off valve body.

[0033] Using the above technical solution, when the hydraulic oil flowing due to the movement of the positioning block is transferred from the transmission pipe to the communication oil pipe, the sealing plug in the communication oil pipe reciprocates. After positioning is completed, since the radial wheel can only move circumferentially along the outer wall of the steel pipe, when the axial movement begins, the radial wheel is subjected to the friction force of the outer wall of the steel pipe, begins to become unbalanced, and rotates around the axis, releasing the valve core.

[0034] Furthermore, this application also provides a method for using a dual-head grinding tool, including the following steps:

[0035] After the industrial robot arm is fixedly connected to the connecting flange on the mounting bracket, the front-end dot laser scanner scans the product position, and then the front-end line laser scanner scans the product position to be polished, generating the polishing trajectory. The data is transmitted to the control system, and then the belt polishing component begins to polish the product. At the same time, the rear-end line laser sensor scans the remaining height of the polishing position and feeds the data back to the control system to ensure the accuracy of product polishing.

[0036] By adopting the above technical solution and through the cooperation of various institutions and systems, the weld grinding work of straight seam steel pipes has become data-driven and standardized. This improves the situation where manual grinding was previously slow and the weld height could not be controlled, effectively reducing labor costs and improving grinding efficiency. At the same time, by changing the limit plate, it can be adapted to straight seam steel pipes of different national standards, increasing the adaptability of the work.

[0037] Furthermore, when the industrial robot arm moves towards the straight seam steel pipe, the positioning block first contacts the outer wall of the steel pipe, and then continues to move downward. Under the support of the elastic element and the pressure from the first hydraulic rod, the two forces are balanced. The axis of the center of the positioning block is always collinear with the radial direction of the cross section of the steel pipe, and the apex of the universal wheel always contacts the outer wall of the steel pipe. Since the length of the limiting rod is fixed, the position of the apex of the universal wheel is fixed, thereby controlling the weld height.

[0038] By adopting the above technical solution, the method of adapting to steel pipes of different diameters, which previously required replacing the limiting plate, is now changed to using the first and second hydraulic rods to counteract the positioning block for positioning. This makes the positioning process simpler and more portable, and can better adapt to steel pipes of different diameters. It reduces operating procedures, saves manpower, material resources and financial resources, and improves work efficiency.

[0039] Furthermore, after the industrial robot begins grinding, since the industrial robot needs to move throughout the grinding process, the position of the positioning block must not be changed. At the start of the movement, the radial wheel will be subjected to axial force, causing the pawl to rotate around the shaft and release the latch. Under the action of the spring, the valve core pushes into the communication oil pipe along the inner cavity of the shut-off valve body to cut off the oil circuit, so that the hydraulic short rod cannot move, thus fixing the positioning block.

[0040] Using the above technical solution, positioning is performed before grinding begins. At this time, the positioning block can move and rotate within a certain range. When grinding begins, as long as there is axial movement relative to the steel pipe, the radial wheel will drive the pawl to release the latch. Under the action of the spring, the valve core quickly pushes into the connecting oil pipe to cut off the oil circuit, preventing the positioning block from moving and affecting the grinding accuracy.

[0041] The beneficial effects of this invention are:

[0042] 1. The product position and grinding position are accurately identified by a dot laser scanner and a front-end line laser scanner, and the grinding height data is fed back in real time; the front and rear grinding heads of the belt sander assembly grind the same position of the product, so that the grinding height of the product meets the requirements; each grinding head of the belt sander assembly can work independently and without affecting each other. Changing the connecting flange allows the sander tool to be connected to industrial robots of various specifications, which is convenient, quick and easy and has good versatility.

[0043] 2. The downward pressure on the positioning block is achieved through the contact mounting base and hydraulic rod, and the upward support force on the positioning block is achieved through the elastic element. When the two forces are in balance, the positioning is completed. After positioning, a 1.5mm weld seam excess height is retained, which precisely controls the weld seam excess height and realizes mechanical positioning. Moreover, it adapts to various pipe diameters during the positioning process without the need to remove parts, which is simple, convenient and improves work efficiency.

[0044] 3. By converting the oscillation of the positioning block into hydraulic flow in the communication oil pipe, and quickly blocking the hydraulic flow when the grinding equipment begins to move axially, the movement of the positioning block is locked. This achieves the benefits of not affecting the positioning effect when positioning begins and maintaining the positioning effect when grinding begins, avoiding grinding errors caused by sensor detection failures of the electrical control equipment. Attached Figure Description

[0045] Figure 1 This is a first-view three-dimensional structural diagram of the present invention;

[0046] Figure 2 This is an exploded view of Embodiment 1 of the present invention;

[0047] Figure 3 This is an assembly diagram of Embodiment 1 of the present invention;

[0048] Figure 4 This is an exploded view of a portion of an embodiment of the present invention;

[0049] Figure 5 This is an assembly diagram of the mechanical support assembly and control assembly according to Embodiment 1 of the present invention;

[0050] Figure 6 This is a location diagram of the belt sanding assembly and the near-end dust collection device according to Embodiment 1 of the present invention;

[0051] Figure 7 This is a perspective view of the belt sanding assembly according to Embodiment 1 of the present invention;

[0052] Figure 8 This is a structural diagram of Embodiment 2 of the present invention;

[0053] Figure 9 This is an assembly diagram of Embodiment 2 of the present invention;

[0054] Figure 10 This is an exploded view of the stretching component according to Embodiment 2 of the present invention;

[0055] Figure 11 This is an exploded view of the fixing component in Embodiment 2 of the present invention;

[0056] Figure 12 This is a schematic diagram illustrating the positioning principle of Embodiment 2 of the present invention;

[0057] Figure 13 This is a structural diagram of Embodiment 3 of the present invention;

[0058] Figure 14 This is an assembly diagram of Embodiment 3 of the present invention;

[0059] Figure 15 This is an exploded view of the transmission component according to Embodiment 3 of the present invention;

[0060] Figure 16 This is an exploded view of the trigger assembly according to Embodiment 3 of the present invention;

[0061] Figure 17 This is a rear view of the trigger assembly according to Embodiment 3 of the present invention.

[0062] In the diagram: 1. Mounting bracket; 2. Mechanical support assembly; 21. Connecting flange; 22. Floating tool mounting base; 23. Scanner mounting base; 24. Proximal dust collection device; 3. Control assembly; 31. Air-floating mechanism; 34. Swinging mechanism; 35. Front-end line laser scanner; 36. Rear-end line laser scanner; 37. Point laser scanner; 4. Belt sanding assembly; 41. Base plate; 42. Servo motor; 43. Drive wheel; 44. Tensioning mechanism; 45. Anti-deviation limiting wheel; 46. Wrap angle limiting wheel; 47. Contact wheel; 48. Limiting plate; 5. Telescopic assembly; 51. Contact mounting base; 52. First rotating groove; 53. First hinge seat; 54. First hydraulic rod; 55. First oil port; 56. Second hydraulic rod; 57. Shaft hole; 58. Hose; 59. Solenoid directional valve; 510, Second oil port; 6, Fixed assembly; 61, Pin seat block; 62, Second rotating groove; 63, First pull ring pin; 64, Limiting rod; 65, First protrusion; 66, Second protrusion; 67, Second hinge seat; 68, Third hinge seat; 69, Positioning block; 610, Elastic element; 611, Universal wheel; 612, Second pull ring pin; 7, Transmission assembly; 71, Driving block; 72, First rotating block; 73, Hydraulic short rod; 74, Piston; 75, Hydraulic cylinder; 76, Transmission pipe; 77, Second rotating block; 78, Passive block; 8, Trigger assembly; 81, Frame; 82, Connecting oil pipe; 83, Sealing plug; 84, Rotating shaft; 85, Claw; 86, Snap-fit; 87, Radial wheel; 88, Shut-off valve body; 89, Valve core; 810, Spring. Detailed Implementation

[0063] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0064] Example 1, referring to Figure 1-7This invention provides a dual-grinding tool, comprising a mounting bracket 1, a dual-grinding unit, a positioning unit, and a locking unit. The dual-grinding unit is mounted on the mounting bracket 1 and is used to connect to a robotic arm to support the entire device and provide limiting. The dual-grinding unit includes a mechanical support assembly 2, mounted on the mounting bracket 1, for providing motion limiting and pressure bearing. The mechanical support assembly 2 includes a connecting flange 21 fixed to the mounting bracket 1 using martensitic cylindrical pins and bolts, a floating tool mounting seat 22 fixed to the bottom of the mounting bracket 1 using bolts, a scanner mounting seat 23 fixed to the bottom of the floating tool mounting seat 22 using bolts, and a bolt-fixed... A near-end dust collection device 24 is fixedly installed at the bottom of the mounting bracket 1; a control component 3 is installed on the mechanical support component 2 to provide motion control during the workflow; a belt sanding component 4 is installed on the control component 3 to sand the weld; a positioning unit is installed on the dual-grinding head unit, which can be achieved by the industrial robot arm providing downward pressure in cooperation with the recognition system and computing unit, and is used to position the weld before and after sanding; a locking unit is installed on the positioning unit, which can lock the relevant motors of the robot arm of the positioning unit after the positioning unit is positioned, and provide a certain load-bearing capacity, and is used to lock the weld position after the positioning unit is positioned to prevent slippage.

[0065] Specifically, most existing straight seam steel pipe weld grinding methods use manual grinding or robotic arms in conjunction with simple grinding equipment, which are insufficient in identifying weld positions and real-time monitoring of weld grinding. In this embodiment, the arm of an industrial robot is fixedly connected to the connecting flange 21, and the connecting flange 21 is fixed together with the mounting bracket 1 and the floating tool mounting seat 22, thereby fixing and limiting the relevant control and execution mechanisms.

[0066] Reference Figure 4-5 The control assembly 3 includes an air-floating mechanism 31 bolted to the floating tool mounting base 22, a swing mechanism 34 bolted to the air-floating mechanism 31, a front-end line laser scanner 35 bolted to the scanner mounting base 23, a rear-end line laser scanner 36 bolted to the scanner mounting base 23, and a dot laser scanner 37 bolted to the front-end line laser scanner 35.

[0067] Specifically, the front-end dot laser scanner 37 scans the product position, and then the front-end line laser sensor scans the product position to be polished, generating a polishing trajectory. The data is transmitted to the control system, and then the belt polishing assembly 4 begins polishing the product. At the same time, the rear-end line laser sensor scans the remaining height of the polishing position and feeds the data back to the control system to achieve the required precision for product polishing. The air floating mechanism 31, in conjunction with the swing mechanism 34, positions the belt polishing assembly 4 in a position that can adapt to the weld seam of the steel pipe and automatically positions the weld seam in the middle of the belt, making the weld seam polished more even, with uniform height and the remaining height meeting the requirements. The swing mechanism 34 is a TCP swing mechanism that uses gravity to adapt to the surface shape of the workpiece, achieving flexible polishing. Ultimately, this tool can be used not only on flexible six-axis robotic arms but also on special-purpose machines that do not have flexibility.

[0068] Reference Figure 6-7 The belt sanding assembly 4 includes a base plate 41 that is limited and mounted on the swing mechanism 34 by pulleys and guide rails, a servo motor 42 that is fixedly mounted on the base plate 41 with bolts, a drive wheel 43 that is fixedly mounted on the servo motor 42, a tensioning mechanism 44 that is fixedly mounted on the base plate 41 with bolts (the tensioning mechanism 44 is a pneumatic mechanism that allows for easy removal and replacement of the sanding belt), an anti-deviation limiting wheel 45 that is fixedly mounted on the base plate 41 with bolts, an angle limiting wheel 46 that is fixedly mounted on the base plate 41 with bolts, a contact wheel 47 that is fixedly mounted on the base plate 41 with bolts, and limiting plates 48 that are fixedly mounted on both sides of the contact wheel 47 with small round nuts.

[0069] Specifically, the sanding belt grinding assembly 4 is supported by the limiting plates 48 on both sides of the contact wheel 47, so that the weld seam height is 1.5mm after the sanding belt grinds the weld seam. The contact wheel 47 is fixedly installed by small round nuts, which facilitates the disassembly and replacement of limiting plates 48 of different diameters to adapt to straight seam steel pipes of different diameters. There are two sanding belt grinding assemblies 4 on a mounting bracket 1, placed one in front and one behind. Specifically, after receiving the command from the control system, the front sanding belt grinding assembly 4 grinds away half of the weld seam, and the rear sanding belt grinding assembly 4 then grinds the remaining weld seam to a height of 1.5mm, improving work efficiency. There are two installation methods for the sanding belt: one is to install it without going around the corner limiting wheel 46, which makes the sanding belt easy to slip and shortens the service life of the sanding belt; the other is to install it around the corner limiting wheel 46, which can increase the wrap angle of the sanding belt, reduce the slippage of the sanding belt, and increase the service life of the sanding belt.

[0070] In use, this embodiment integrates the grinding of straight seam steel pipe welds into one device. By using an industrial robot to control this embodiment, multiple steps such as weld identification, positioning, trajectory planning, primary grinding, dust collection, and secondary grinding of the steel pipe are completed in one go, improving work efficiency and reducing additional expenditures of manpower, material resources, and financial resources. Due to the adoption of multiple electrical devices including an air floating mechanism 31, a front-end line laser scanner 35, a rear-end line laser scanner 36, and a point laser scanner 37, the grinding accuracy is high and the path trajectory is traceable. Each grinding head of the two sanding belt grinding components 4 can work independently without affecting each other. The interchangeable connecting flange 21 allows the grinding tool to be connected to industrial robots of various specifications, which is convenient, fast, and has good versatility.

[0071] Example 2, refer to Figure 8-12 This is a second embodiment of the present invention, which differs from the first embodiment in that: the positioning unit includes a telescopic assembly 5, which is mounted on the belt sanding assembly 4 to provide support force when controlling the weld height; the telescopic assembly 5 includes a contact mounting seat 51 fixedly mounted on the outside of the contact wheel 47 with bolts, a first rotating groove 52 opened on the contact mounting seat 51, a first hinge seat 53 welded to both sides of the contact mounting seat 51, a first hydraulic rod 54 pinned to the first hinge seat 53, a first oil port 55 fixedly mounted on the first hydraulic rod 54, a second hydraulic rod 56 movably sleeved inside the first hydraulic rod 54, a shaft hole 57 fixedly mounted at the end of the second hydraulic rod 56, a hose 58 fixedly mounted on the first oil port 55, an electromagnetic reversing valve 59 fixedly mounted at the end of the hose 58, and a second oil port 510 fixedly mounted on the electromagnetic reversing valve 59, the second oil port 510 being connected to a hydraulic pump; and a fixing assembly 6, mounted on the telescopic assembly 5, for adaptive positioning at a specific position on the straight seam steel pipe.

[0072] Specifically, in Embodiment 1, the limit plate 48 needs to be replaced to accommodate steel pipes of different diameters. In this embodiment, the solenoid directional valve 59 is opened and oil is introduced. The hydraulic oil enters the hose 58 through the solenoid directional valve 59, and then the hydraulic oil enters the first hydraulic rod 54 through the first oil inlet and pushes the second hydraulic rod 56 to move. The solenoid directional valve 59 has two oil outlets, which are respectively connected to the first hydraulic rods 54 on both sides of the contact mounting base 51, so that the first hydraulic rods 54 on both sides maintain the same pressure. In other words, the second hydraulic rod 56 has the same degree of extension.

[0073] After the second hydraulic rod 56 extends to the specified length, the solenoid directional valve 59 closes, blocking the oil inlet or outlet, and simultaneously blocking the connection between the first oil ports 55 on both sides of the contact mounting base 51, to prevent the second hydraulic rod 56 on both sides from extending to different degrees, which would lead to inaccurate positioning.

[0074] Reference Figure 11The fixing assembly 6 includes a pin seat block 61 bolted to the contact mounting base 51, a second rotating groove 62 formed on the pin seat block 61, a first pull ring pin 63 sleeved in the second rotating groove, a limiting rod 64 pinned to the rotating pin, a first protrusion 65 fixedly mounted on the limiting rod 64, a second protrusion 66 fixedly mounted on the limiting rod 64, a second hinge seat 67 fixedly mounted at the end of the limiting rod 64, a third hinge seat 68 fixedly mounted on one side of the second hinge seat 67, a positioning block 69 hinged to the second hinge seat 67, elastic members 610 fixedly mounted on both sides of the positioning block 69, a caster wheel 611 fixedly mounted in the middle of the positioning block 69, and a second pull ring pin 612 sleeved in the contact mounting base 51.

[0075] Specifically, the first hydraulic rod 54 is hinged to the first hinge seat 53, and one end of the second hydraulic rod 56 is hinged to the third hinge seat 68. When hydraulic oil enters the first hydraulic rod 54, the second hydraulic rod 56 applies pressure to the positioning block 69 through the third hinge seat 68. The elastic element 610 on the side of the positioning block 69 away from the limit wheel is subjected to greater pressure.

[0076] Since the limiting rod 64 is non-extendable, the distance B from the axis of the pin hole formed by the first rotating groove 52 and the second rotating groove 62 to the rotation axis of the second hinge seat 67 is 45mm, and the distance C from the rotation axis of the second hinge seat 67 to the apex of the universal wheel 611 is 20mm. The swing angle of the universal wheel 611 is 11°. Under the push of the hydraulic rod, when the apex of the universal wheel 611 contacts the outer wall of the steel pipe, at this swing angle of 11°, the axis of the universal wheel 611 cannot be perpendicular to the tangent of the outer wall of the steel pipe at that point, that is, it cannot be collinear with the radial direction of the cross section of the steel pipe at that point. This causes the elastic force of the elastic elements 610 on both sides of the positioning block 69 to be unequal. Under the pressure of the second hydraulic rod 56 and the elastic force of the elastic elements 610, there is a component force acting on the positioning block 69 in the direction tangential to the outer wall of the steel pipe, which makes the positioning block 69 tend to continue to move along the outer wall of the lever.

[0077] During the movement, the first hydraulic rod 54, the second hydraulic rod 56, the positioning block 69, the limiting rod 64, and the contact mounting seat 51 together form a four-bar linkage, causing the pressure on the elastic element 610 on the side of the positioning block 69 away from the limiting wheel to gradually decrease, while the pressure on the elastic element 610 on the other side gradually increases, until the pressure on both elastic elements 610 is the same, and the universal wheel 611 is perpendicular to the outer wall of the steel pipe. In other words, the positioning is completed.

[0078] The positioning on both sides is carried out simultaneously, so that the distance between the line connecting the contact point of the universal wheels 611 on both sides with the outer wall of the steel pipe and the vertex of the outer wall of the steel pipe on the side of the limiting wheel, that is, the distance between the vertex of the outer wall of the steel pipe on the side of the limiting wheel and the vertex of the sanding belt is E=1.5mm, which controls the excess height of the weld seam during grinding. After the positioning is completed, the grinding work can be carried out. This positioning process can cover steel pipes with different diameters from 325mm to 1420mm.

[0079] To prevent the limiting rod 64 from rotating excessively and reaching an inflection point, the first protrusion 65 will interfere with the second pull ring pin 612 when it opens, and the second protrusion 66 will interfere with the second pull ring pin 612 when the limiting rod 64 closes, ultimately causing the limiting rod 64 to rotate within a fixed range.

[0080] During use, hydraulic pressure is applied downwards, and the elastic force of the elastic element 610 provides an upward thrust perpendicular to the outer wall of the steel pipe. This allows for a comparison of forces on both sides, with the universal wheel 611 as the fulcrum, ultimately making the universal wheel 611 perpendicular to the outer wall of the steel pipe, thus completing the positioning. The positioning principle is that since the universal wheel 611 is ultimately perpendicular to the outer wall of the steel pipe, the axial angle between B and C is a constant value. That is, with B and C as two sides of a triangle, the length D of the third side is a constant value. At the apex of the outer wall of the steel pipe, the sanding belt is aligned with it at a distance of 1.5mm. The intersection point between the length E and the outer wall of the steel pipe is exactly one, simplifying the positioning process and automatically achieving positioning. It can adapt to all straight seam steel pipes with an outer diameter from 325mm to 1420mm, expanding its applicability. It eliminates the need to disassemble and install the corresponding limiting piece 48, improving work efficiency and saving manpower, material resources, and financial resources. The remaining structure is the same as in Example 1.

[0081] Example 3, referring to Figure 13-17 This is the third embodiment of the present invention, which differs from the second embodiment in that: the locking unit includes a transmission component 7, which is mounted on the fixing component 6 and is used to transmit the movement of the fixing component 6.

[0082] The transmission assembly 7 includes an active block 71 bolted to a positioning block 69, a first rotating block 72 hinged to the active block 71, a hydraulic short rod 73 fixedly mounted on the rotating block, a piston 74 fixedly mounted on the hydraulic short rod 73, a hydraulic cylinder 75 movably sleeved outside the piston 74, a transmission pipe 76 fixedly mounted on the outer wall of the hydraulic cylinder 75, a second rotating block 77 fixedly mounted at the end of the hydraulic cylinder 75, and a passive block 78 bolted to a third hinge seat 68.

[0083] The trigger assembly 8 is mounted on the transmission assembly 7 and is used to lock the movement of the transmission assembly 7.

[0084] Specifically, after positioning, the weld seam needs to be ground along the axis of the steel pipe. During the movement, in order to prevent unpredictable tilting or swaying during the rotation of the universal wheel 611 of the positioning block 69, the swaying is transmitted to the first rotating block 72 through the active block 71. The first rotating block 72 transmits the movement to the piston 74 on the hydraulic short rod 73. Since the positioning block 69 moves, the third hinge seat 68 will rotate relative to it. The relative movement amplitude is the sum of the two, which causes the hydraulic oil in the hydraulic cylinder 75 to be squeezed out or sucked in. In other words, the movement of the positioning block 69 is converted into the movement of the hydraulic oil for control and blocking.

[0085] Reference Figure 16-17 The trigger assembly 8 includes a frame 81 bolted to a pin block 61, a communication oil pipe 82 fixedly mounted on the frame 81, a sealing plug 83 movably fitted inside the communication oil pipe 82, a rotating shaft 84 fixedly mounted at one end of the frame 81, a pawl 85 hinged to the rotating shaft 84, a latch 86 fixedly mounted at one end of the pawl 85, a radial wheel 87 movably mounted at the other end of the pawl 85, a shut-off valve body 88 fixedly mounted on the frame 81, a valve core 89 movably fitted inside the shut-off valve body 88, and a spring 810 movably mounted inside the shut-off valve body 88.

[0086] Specifically, the trigger assembly 8 connects the hydraulic oil in the transmission pipe 76 to the communication pipe 82. The communication pipe 82 contains a sealing plug 83. When the positioning block 69 moves, the sealing plug 83 will also start to move accordingly. The stroke of the sealing plug 83 is limited by the communication pipe 82. In other words, the limited stroke prevents the hydraulic oil in the transmission pipe 76 from overflowing uncontrollably or being sucked in in large quantities, thus preventing the positioning block 69 from moving to a dead position and affecting the operation. The end of the communication pipe 82 is connected to the hydraulic oil tank to ensure the oil supply.

[0087] When the positioning block 69 moves along the outer wall of the steel pipe, the radial wheel 87 contacts the outer wall of the steel pipe and follows its movement. However, because the radial wheel 87 is restricted in its degree of freedom by the pawl 85 and the rotating shaft 84, it cannot move axially. In other words, when the entire device starts grinding and moves axially, the side of the radial wheel 87 will be subjected to the friction of the outer wall of the steel pipe, causing the radial wheel 87 to rotate around the rotating shaft 84. Since the buckle 86 at the end of the pawl 85 is engaged in the groove opened on the valve core 89, the buckle 86 disengages from the valve core 89 due to the movement of the radial wheel 87. Under the push of the spring 810, the valve core 89 moves quickly along the inner cavity of the cut-off valve body 88, pushes into the communication oil pipe 82, cuts off the oil circuit, and prevents the hydraulic cylinder 75 and piston 74 from moving, thereby locking the movement of the positioning block 69.

[0088] During use, the movement of the positioning block 69 is converted into the movement of hydraulic oil in the transmission pipe 76 or the communication oil pipe 82. The axial movement of the device is used as a trigger condition to lock the movement of the positioning block 69. The device is responsive and reliable, avoiding grinding errors caused by the deflection of the positioning block 69, as well as grinding errors caused by slow or incomplete locking. This helps improve grinding accuracy, reduce labor and material costs, and increase efficiency. The remaining structure is the same as that in Embodiment 2.

[0089] Example 4, refer to Figure 1-17 The fourth embodiment of the present invention provides a method for using a dual-head grinding tool, comprising the following steps:

[0090] Step 1: After the industrial robot installs the present invention via its arm and connecting flange 21, the front-end dot laser scanner 37 scans the product position, and then the front-end line laser sensor scans the product position to be polished, generating a polishing trajectory and transmitting the data to the control system. Then, the belt polishing assembly 4 begins to polish the product. The two grinding heads of the belt polishing assembly 4 polish the same weld location twice in succession. The first time, half of the weld is polished away, and the second time, the weld height is controlled to 1.5mm. At the same time, the dust particles from the polishing are collected into the near-end dust collection device 24. The two grinding heads rotate in opposite directions, emitting the dust particles to the near-end dust collection device 24 in the middle. The belt polishing assembly 4 can automatically press the limiting plate 48 against the surface of the steel pipe due to its own gravity, controlling the weld height. When changing steel pipes of different diameters, the limiting plate 48 can be replaced simply by unscrewing the small round nut.

[0091] Step 2: During positioning, the solenoid directional valve 59 is opened, causing the first hydraulic rod 54 and the second hydraulic rod 56 to extend, providing downward pressure to the positioning block 69. Simultaneously, the elastic element 610 provides an outward elastic force perpendicular to the outer wall of the steel pipe. Under the push of the hydraulic rods, when the apex of the universal wheel 611 contacts the outer wall of the steel pipe, because the axis of the universal wheel 611 at this 11° swing angle is not perpendicular to the tangent of the outer wall of the steel pipe at that point (i.e., not collinear with the radial direction of the cross-section of the steel pipe), the elastic elements 610 on both sides of the positioning block 69 are aligned with the positioning block. The elastic forces of the positioning blocks 69 are not equal. Under the pressure of the second hydraulic rod 56 and the elastic force of the elastic element 610, there is a component force acting on the positioning block 69 in the direction tangential to the outer wall of the steel pipe, which makes the positioning block 69 tend to continue to move along the outer wall of the lever. During the movement, the pressure on the elastic element 610 on the side of the positioning block 69 away from the limit wheel gradually decreases, while the pressure on the elastic element 610 on the other side gradually increases until the pressure on both elastic elements 610 is the same, and the universal wheel 611 is perpendicular to the outer wall of the steel pipe. In other words, the positioning is completed.

[0092] Step 3: To prevent unpredictable tilting or swaying during the rotation of the caster 611 of the positioning block 69, the sway is transmitted to the first rotating block 72 via the active block 71. The first rotating block 72 transmits the motion to the piston 74 on the hydraulic short rod 73, causing the hydraulic oil in the hydraulic cylinder 75 to be squeezed out or drawn in, converting the motion of the positioning block 69 into the motion of the hydraulic oil. When the positioning block 69 moves along the outer wall of the steel pipe, the radial wheel 87 contacts the outer wall of the steel pipe and follows its movement. When the entire device begins grinding... When the radial wheel 87 moves axially, the side of the radial wheel 87 will be subjected to the friction force of the outer wall of the steel pipe, causing the radial wheel 87 to rotate around the shaft 84. Since the buckle 86 at the end of the pawl 85 is engaged in the groove opened on the valve core 89, the buckle 86 disengages from the valve core 89 due to the movement of the radial wheel 87, causing the valve core 89 to move rapidly along the inner cavity of the cut-off valve body 88 under the push of the spring 810, push into the communication oil pipe 82, cut off the oil circuit, so that the hydraulic cylinder 75 and piston 74 cannot move, thereby locking the movement of the positioning block 69.

[0093] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A dual-head grinding tool, comprising a mounting bracket, characterized in that: It also includes a dual-grinding head unit, a positioning unit, and a locking unit; The dual-grinding-head unit is mounted on a bracket and is used to connect with the robotic arm to support the entire device and provide limits. The dual-grinding head unit includes: a mechanical support assembly mounted on a mounting bracket for providing motion limiting and pressure bearing; the mechanical support assembly includes a connecting flange mounted on the mounting bracket, a floating tool mounting base mounted at the bottom of the mounting bracket, a scanner mounting base mounted at the bottom of the floating tool mounting base, and a near-end dust collection device mounted at the bottom of the mounting bracket. A control component, mounted on the mechanical support assembly, is used to provide motion control during the workflow; A belt abrasive grinding assembly, mounted on the control assembly, is used for grinding weld seams; The positioning unit is set on the dual-grinding head unit and is used to position the weld before and after grinding the weld. The locking unit is mounted on the positioning unit and is used to lock the weld after the positioning unit positions the weld to prevent slippage. The positioning unit includes a telescopic component, which is mounted on the belt abrasive assembly to provide support force when controlling the weld height; The telescopic assembly includes a contact mounting seat disposed on the outside of the contact wheel, a first rotating groove formed on the contact mounting seat, first hinge seats disposed on both sides of the contact mounting seat, a first hydraulic rod disposed on the first hinge seat, a first oil port disposed on the first hydraulic rod, a second hydraulic rod disposed inside the first hydraulic rod, a shaft hole disposed at the end of the second hydraulic rod, a hose disposed on the first oil port, an electromagnetic reversing valve disposed at the end of the hose, and a second oil port disposed on the electromagnetic reversing valve; A fixing component, mounted on the telescopic component, is used for adaptive positioning at a specific location on the straight seam steel pipe; The fixing assembly includes a pin seat block disposed on the contact mounting base, a second rotating groove formed on the pin seat block, a first pull ring pin disposed in the second rotating groove, a limiting rod disposed on the first pull ring pin, a first protrusion disposed on the limiting rod, a second protrusion disposed on the limiting rod, a second hinge seat disposed at the end of the limiting rod, a third hinge seat disposed on one side of the second hinge seat, a positioning block disposed on the second hinge seat, elastic members disposed on both sides of the positioning block, a universal wheel disposed in the middle of the positioning block, and a second pull ring pin disposed on the contact mounting base; The locking unit includes a transmission component, which is disposed on the fixing component and is used to transmit the movement of the fixing component. The transmission assembly includes an active block disposed on a positioning block, a first rotating block disposed on the active block, a hydraulic short rod disposed on the rotating block, a piston disposed on the hydraulic short rod, a hydraulic cylinder disposed outside the piston, a transmission pipe disposed on the outer wall of the hydraulic cylinder, a second rotating block disposed at the end of the hydraulic cylinder, and a passive block disposed on a third hinge seat. A trigger assembly, mounted on the transmission assembly, is used to lock the movement of the transmission assembly; The trigger assembly includes a frame mounted on a pin block, a connecting oil pipe mounted on the frame, a sealing plug inside the connecting oil pipe, a rotating shaft at the end of the frame, a pawl mounted on the rotating shaft, a latch at one end of the pawl, a radial wheel at the other end of the pawl, a shut-off valve body mounted on the frame, a valve core inside the shut-off valve body, and a spring inside the shut-off valve body.

2. The dual-head grinding tool according to claim 1, characterized in that: The control components include a pneumatic floating mechanism mounted on a floating tool mounting base, a swing mechanism mounted on the pneumatic floating mechanism, a front-end line laser scanner mounted on a scanner mounting base, a rear-end line laser scanner mounted on a scanner mounting base, and a point laser scanner mounted on the front-end line laser scanner.

3. A dual-head grinding tool according to claim 2, characterized in that: The belt sanding assembly includes a base plate mounted on a swing mechanism, a servo motor mounted on the base plate, a drive wheel mounted on the servo motor, a tensioning mechanism mounted on the base plate, an anti-deviation limiting wheel mounted on the base plate, a wrap-around limiting wheel mounted on the base plate, a contact wheel mounted on the base plate, and limiting plates mounted on both sides of the contact wheel.

4. A method of using a dual-head grinding tool, comprising the dual-head grinding tool described in claim 3, characterized in that: Includes the following steps, After the industrial robot arm is fixedly connected to the connecting flange on the mounting bracket, the front-end dot laser scanner scans the product position, and then the front-end line laser scanner scans the product position to be polished, generating the polishing trajectory. The data is transmitted to the control system, and then the belt sanding component begins to polish the product. At the same time, the rear-end line laser sensor scans the polishing position height and feeds the data back to the control system to ensure the accuracy of product polishing. When the industrial robot arm moves towards the straight seam steel pipe, the positioning block first contacts the outer wall of the steel pipe and then continues to move downward. Under the support of the elastic element and the pressure from the first hydraulic rod, the two forces are balanced. The axis of the center of the positioning block is always collinear with the radial direction of the cross section of the steel pipe, and the apex of the universal wheel always contacts the outer wall of the steel pipe. Since the length of the limiting rod is fixed, the position of the apex of the universal wheel is fixed, thereby controlling the weld reinforcement height. After the industrial robot starts grinding, the position of the positioning block must not be changed because the industrial robot needs to move throughout the grinding process. At the start of the movement, the radial wheel will be subjected to axial force, causing the pawl to rotate around the axis and release the latch. Under the action of the spring, the valve core pushes into the communication oil pipe along the inner cavity of the shut-off valve body to cut off the oil circuit, so that the hydraulic short rod cannot move, thus fixing the positioning block.

Images