An automatic grinding device for stiffening circumferential welds of pressure steel pipes

Abstract

This utility model discloses an automatic grinding device for stiffening ring welds of pressure steel pipes, including a base, a fixed bracket, a movable bracket, and a floating grinding unit. Two sets of bases are movably connected by two threaded transmission screws that are parallel to each other and perpendicular to the bases. The outer ends of the threaded transmission screws are rotatably fixed. The lower parts of both ends of the fixed bracket are fixed to the two bases. The lower part of the movable bracket is hinged to the base, and the upper part is adjustablely connected to the top of both ends of the fixed bracket via hydraulic rods. The floating grinding unit is an electric grinding device, and multiple sets of floating grinding units are fixedly arranged on the crossbeam of the movable bracket at intervals according to the position of the stiffening rings of the pressure steel pipes. This utility model uses a bracket to fix multiple floating grinding units, and utilizes a transverse screw transmission mechanism, a radial electro-hydraulic servo lifting system, and an automatic steel pipe rotation device to achieve the function of simultaneously grinding and removing rust from six stiffening rings before welding by a single operator, improving efficiency and the quality of rust removal and grinding.

Description

Technical Field

[0001] This utility model relates to the field of pressure steel pipe manufacturing technology, and in particular to an automatic grinding device and construction method for the weld seam at the stiffening ring installation position of pressure steel pipe with axial positioning and radial adaptive adjustment functions, which is suitable for batch pretreatment of circumferential weld seams on the outer wall of large-diameter pressure steel pipes. Background Technology

[0002] The typical steps for on-site fabrication of pressure steel pipes include: after the steel plates are transported to the site, they are cut, prepared, rolled, assembled into circles, and welded to form complete circular pipe sections. On each circular pressure steel pipe section, a stiffening ring needs to be installed at intervals of 1-1.5 meters, depending on design requirements and stress levels. Before installing the stiffening rings, the welding positions for the stiffening rings must be cleaned and polished to remove rust.

[0003] Traditional rust removal and grinding involves manual grinding by workers using a handheld floating grinding unit. Taking a standard φ5000mm pressure steel pipe section, 6m long, with stiffening rings spaced 1m apart, as an example, the rust removal and grinding width is 100mm, requiring 6 stiffening rings per section, and the weld seam rust removal and grinding length is 94.2m. One worker using a handheld floating grinding unit would need to grind continuously for 8 hours.

[0004] Manual grinding faces three major technical bottlenecks: limited operating space, requiring workers to look upwards throughout the process, leading to fatigue; uneven grinding pressure resulting in surface roughness differences exceeding 30%; and severe dust pollution, with noise levels exceeding 85 dB(A). Therefore, existing rust removal and grinding processes are inefficient, environmentally unfriendly, and fail to meet quality requirements. Summary of the Invention

[0005] This utility model discloses an automatic grinding device for stiffening ring welds of pressure steel pipes, addressing the shortcomings of existing technologies. The purpose of this utility model is to provide a convenient operating method that utilizes floating grinding units. Multiple floating grinding units are fixed to supports according to the installation spacing of the stiffening rings. A transverse screw drive mechanism and a radial electro-hydraulic servo lifting system, combined with an automatic steel pipe rotation device, enable one-person operation. Simultaneously, it performs rust removal and grinding at all six stiffening ring installation positions before welding, improving efficiency and rust removal and grinding quality.

[0006] To solve the above problems, the technical solution adopted by this utility model is as follows: An automatic grinding device for stiffened circumferential welds of pressure steel pipes is characterized in that: the grinding device is a steel frame support structure, including a base, a fixed bracket, a movable bracket and a floating grinding unit; The base is arranged in two parallel sets and is movably connected by two threaded transmission screws that are parallel to each other and perpendicular to the base. The outer ends of the two threaded transmission screws are rotatably connected to a fixed seat fixed on a horizontal ground. Each threaded transmission screw is threadedly connected to the base so that the base moves synchronously with the rotation of the screw. The fixed support is a steel frame structure, with the steel frame vertically arranged and the lower ends of both ends fixed to two bases; The movable support is a steel frame structure. The steel frame is vertically arranged and parallel to the fixed support. The lower ends of both ends are hinged to the base through rotating shafts, and the upper part is adjustablely connected to the top of both ends of the fixed support through hydraulic rods. The floating grinding unit is an electric grinding device. Multiple floating grinding units are fixedly installed on the crossbeam of the movable support at intervals according to the position of the pressure steel pipe stiffening ring.

[0007] Furthermore, the upper beam of the movable support is provided with fixing clips at both ends for fixing the two ends of the pressure steel pipe; the fixing clips include folding arms that are respectively vertically connected and fixed to both ends of the support, and each folding arm is provided with rollers for sliding limit when the pressure steel pipe opening rotates.

[0008] Furthermore, the two ends of the fixed bracket are supported and fixed to the base by diagonal braces.

[0009] Furthermore, the hydraulic rod is driven to extend and retract by an electro-hydraulic servo lifting system mounted on the base; the electro-hydraulic servo lifting system includes a motor and a hydraulic pump driven by it, and the hydraulic pump is connected to the hydraulic rod through an oil pipe.

[0010] The floating grinding unit includes a linkage controller, multiple fixed electric grinding wheels, and spring support seats. The floating grinding unit is a high-efficiency grinding device that integrates automated control, elastic buffering, and multi-station collaborative operation. Through elastic support adjustment and centralized control, it achieves adaptive contact between the grinding head and the workpiece surface, avoiding workpiece damage or grinding tool jamming caused by rigid contact, while improving the efficiency of multi-station collaborative operation.

[0011] The main body of the linkage controller includes a programmable logic controller as the control core, and integrates a power supply module, a relay output unit and a human-machine interface; it also includes a control switch module and a status feedback unit.

[0012] The fixed electric grinding machine includes a fixed wide-face abrasive wheel grinding head, the abrasive wheel being rigidly connected to the output shaft via a quick-release flange with a keyway positioning structure; it is equipped with a series-wound asynchronous motor, with a flange interface at the bottom, and is rigidly connected to a spring support seat via bolts.

[0013] The spring support base is a double-spring assembly, with two springs symmetrically arranged on both sides of the grinding head in each group. A guide rod is installed inside the spring, and a limit block is set at the top of the guide rod. A threaded adjusting nut is equipped at the bottom of the spring. The initial compression of the spring is changed by rotating the nut to achieve the preset contact pressure. The bottom of the spring support base is connected to the movable bracket by a hinge, which can rotate ±15° around the horizontal axis and achieve ±200mm displacement along the axial direction of the bracket through a screw adjustment mechanism.

[0014] Compared with existing technologies, this utility model device has the following advantages: Based on the installation spacing of the stiffening rings, this utility model device sets up multiple floating grinding units through fixed and movable supports. Utilizing the transverse screw transmission mechanism and radial electro-hydraulic servo lifting system of the supports, in conjunction with an automatic steel pipe rotation device, it enables one worker to operate and simultaneously grind and remove rust from multiple stiffening ring installation positions before welding. The steel pipe only needs to rotate once to achieve rust removal and grinding for multiple sections, saving time and significantly increasing throughput. Remote control operation further reduces manpower and enhances safety. This utility model device utilizes multiple floating grinding unit supports to achieve the function of simultaneously grinding and removing rust from multiple stiffening ring installation positions before welding. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the automatic polishing device of this utility model.

[0016] Figure 2 This is a front structural diagram of the automatic polishing device of this utility model.

[0017] Figure 3 This is a side view of the automatic polishing device of this utility model.

[0018] Reference numerals in the attached diagram: 1 is a fixed bracket, 2 is a fixing clip, 3 is a floating grinding unit, 4 is a movable bracket, 5 is a rotating shaft, 6 is a fixed base, 7 is a threaded transmission screw, 8 is a hydraulic rod, and 9 is a base. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments. These specific embodiments are further explanations of the principle of the present invention and are not intended to limit the present invention in any way. Any technology that is the same as or similar to the present invention does not exceed the protection scope of the present invention.

[0020] Referring to the accompanying drawings, the automatic grinding device for stiffening ring welds of pressure steel pipes according to this utility model includes a double-row support bracket. Multiple floating grinding units 3 are mounted and fixed on the support bracket, enabling simultaneous grinding of the outer wall of the pressure steel pipe by multiple floating grinding units 3. The support bracket can move the transmission rod axially according to the position of the pressure steel pipe and the stiffening ring to match the position of the floating grinding unit 3 to the installation position of the stiffening ring. The electro-hydraulic servo lifting system adjusts radially through the extension and retraction of the hydraulic rod 8, ensuring that the floating grinding unit 3 is in contact with the outer wall of the pressure steel pipe.

[0021] The device in this embodiment of the utility model completes the rust removal and grinding of the entire ring before welding at the installation position of the stiffening ring by means of the self-rotation of the floating grinding unit 3 and the overall rotation of the pressure steel pipe.

[0022] As shown in the figure, the support bracket in this embodiment of the utility model is a double-row frame type bracket, with the rear row being a fixed bracket 1 and the front row being a movable bracket 4. The movable bracket 4 is an electro-hydraulic servo lifting system rod + rotating shaft adjustment structure bracket.

[0023] The rear fixed bracket 1 is the main load-bearing bracket, which meets the requirements of overall stability of the bracket, support force of the electro-hydraulic servo lifting system rod, and counter-thrust force during grinding.

[0024] The front movable support 4 is supported at the bottom by two sets of rotating shafts 5 to achieve corner rotation, and at the top by two hydraulic rods 8 to connect to the fixed support 1. Multiple floating grinding units 3 are fixed on the crossbar of the movable support 4 at stiffening ring intervals. The front end of the floating grinding unit 3 is supported by springs to ensure a tight fit between the grinding surface and the steel pipe surface.

[0025] The threaded drive screw 7 can achieve movement and positioning with a lead of 200mm and a positioning accuracy of ±0.5mm, and is fixed to the ground by four fixed seats 6. The threaded drive screw 8 can precisely adjust the axial position of the bracket to accurately match the position of the pressure steel pipe and stiffening ring.

[0026] like Figure 1 , Figure 2 , Figure 3 As shown, the automatic grinding device for stiffening circumferential welds of pressure steel pipes in this embodiment of the present invention is a double-row frame type support, including a rear fixed support 1 and a rotatable and adjustable front movable support 4. The fixed support 1 is the main force-bearing support, which is reinforced and fixed by the main frame and diagonal support, which can meet the overall stability of the device and bear the supporting force of the electro-hydraulic servo lifting system 1 rod, the counter-thrust force during grinding, etc.

[0027] The upper part of the movable bracket 4 is adjustablely connected to the top of the rear fixed bracket 1 via a hydraulic rod 8. The lower part of the movable bracket 4 is hinged to the base of the fixed bracket 1 via a pivot 5. The bottom of the movable bracket 4 can be rotated and adjusted via the pivot 5.

[0028] The top of both ends of the movable support 4 are connected to the top of the fixed support 1 by two 8 hydraulic rods; multiple floating grinding units 3 are fixedly installed on the crossbar of the movable support 4 according to the stiffening ring spacing. In this example, there are six floating grinding units 3.

[0029] The floating mechanism of the floating grinding unit 3 uses a helical spring made of 60Si2Mn spring steel with an elastic modulus of 206GPa. At a pre-compression of 15mm, it can provide 120N of normal pressure to ensure a tight fit between the grinding surface and the steel pipe surface. The grinding wheel is made of brown corundum with a grit size of 60 mesh and a linear speed of 35m / s.

[0030] This embodiment of the floating grinding unit is a high-efficiency grinding device that integrates automated control, elastic buffering, and multi-station collaborative operation. Through elastic support adjustment and centralized control, it achieves adaptive contact between the grinding head and the workpiece surface, avoiding workpiece damage or grinding tool jamming caused by rigid contact, while improving the efficiency of multi-station collaborative operation.

[0031] The floating grinding unit includes a linkage controller, multiple fixed electric grinding wheels, and spring support bases.

[0032] The linkage controller uses a programmable logic controller (PLC) as its core, integrating a power supply module, relay output unit, and human-machine interface. The control switch module includes group control buttons and individual unit control knobs, allowing switching between three modes: "multiple units synchronous start / stop," "individual unit independent start / stop," or "group sequential start / stop," via touch or mechanical operation. The status feedback unit is equipped with LED indicators (red - fault, green - running, yellow - standby) and a buzzer alarm module, providing real-time feedback on the grinding wheel's operating status (such as overload, stall, and power supply abnormality).

[0033] This is a stationary electric grinder, featuring a fixed wide-faced abrasive wheel grinding head. The abrasive wheel specifications are: diameter 100-150mm, width 50-80mm, base material is resin bonded + brown corundum abrasive, and the abrasive wheel is rigidly connected to the output shaft via a quick-release flange with a keyway positioning structure. It is equipped with a series-wound asynchronous motor. A flange interface is provided at the bottom, rigidly connected to a spring support base via bolts to ensure no relative displacement between the grinding head and the support base.

[0034] The spring support uses a double-spring assembly, employing cylindrical helical compression springs made of 60Si2MnA high-strength spring steel. Two springs are symmetrically arranged on each side of the grinding head. Spring parameters: diameter 8-12mm, free length 100-150mm, elastic modulus 50-80N / mm, working limit compression ≤30mm. A 45# steel guide rod is inserted inside the spring, working with a linear bearing to ensure no radial off-center load during spring extension and contraction. A limit block (PTFE material) is installed at the top of the guide rod to limit the maximum compression stroke. A threaded adjusting nut is fitted at the bottom of the spring; rotating the nut changes the initial compression, achieving preset contact pressure. When the grinding head contacts the outer wall of the pressure steel pipe, if there is a protrusion on the workpiece surface, the spring is compressed and the grinding head "passively floats" with the workpiece contour; if the surface is concave, the spring rebounds, and the grinding head "actively follows." The bottom of the spring support is connected to the movable bracket by a hinge. To accommodate the deviation of the steel pipe axis, it can rotate ±15° around the horizontal axis and achieve ±200mm displacement along the bracket axis through the screw adjustment mechanism to adapt to different grinding positions.

[0035] Threaded drive screws 7 are installed on the front and rear sides of the base of the fixed bracket 1. Both ends of each threaded drive screw 7 are fixed to the ground through the fixed seat 6. When the threaded drive screw 7 rotates, it can precisely adjust the axial position of the base of the fixed bracket 1 to drive the movable bracket 4 to move, and adjust the position of the floating grinding unit 3 on the movable bracket 4 to precisely match the position of the stiffening ring of the pressure steel pipe.

[0036] The fixed support 1 and the movable support 4 are equipped with an electro-hydraulic servo lifting system, which consists of an electric hydraulic pump, two high-pressure oil pipes, and two hydraulic rods 8. The electric hydraulic pump controls the piston of the hydraulic rods 8 to extend and retract, adjusting the movable support 4 and the floating grinding unit 3 to fit against the outer wall of the pressure steel pipe.

[0037] The movable support 4 is equipped with fixing clips 2 at both ends. The fixing clips 2 are fastened to the end faces of the pressure steel pipe to ensure that the relative position of the movable support 4 and the pressure steel pipe does not shift when the pressure steel pipe rotates. The fixing clips 2 are bent inward at 90° from the support position, and their width coincides with the opening of the pressure steel pipe. Two sets of roller devices are used to fit against the opening of the pressure steel pipe, which plays a role in limiting and positioning when the pressure steel pipe rotates.

[0038] After the pressure steel pipe is transported to the grinding station via a rolling trolley, the rotating device of the rolling trolley is activated to make the pressure steel pipe rotate. The threaded drive screw 7 is adjusted to align the floating grinding unit 3 with the stiffening ring of the pressure steel pipe, and the fixing clips 2 are aligned so they can be inserted into the end faces of the pressure steel pipe. The electric hydraulic pump is started, and the hydraulic rod 8 is adjusted so that the floating grinding unit 3 is in contact with the outer wall of the pressure steel pipe, and the fixing clips 2 are inserted into the end faces of the pressure steel pipe. The power supply to the floating grinding unit 3 is then activated, causing the grinding head of the floating grinding unit 3 to rotate in contact with the outer wall of the pressure steel pipe, achieving simultaneous grinding of all weld seams of the pressure steel pipe.

Claims

1. An automatic grinding device for stiffening circumferential welds of pressure steel pipes, characterized in that: The grinding device is a steel frame support structure, including a base, a fixed bracket, a movable bracket, and a floating grinding unit; The base is arranged in two parallel sets and is movably connected by two threaded transmission screws that are parallel to each other and perpendicular to the base. The outer ends of the two threaded transmission screws are rotatably connected to a fixed seat fixed on a horizontal ground. Each threaded transmission screw is threadedly connected to the base so that the base moves synchronously with the rotation of the screw. The fixed support is a steel frame structure, with the steel frame vertically arranged and the lower ends of both ends fixed to two bases; The movable support is a steel frame structure. The steel frame is vertically arranged and parallel to the fixed support. The lower ends of both ends are hinged to the base through rotating shafts, and the upper part is adjustablely connected to the top of both ends of the fixed support through hydraulic rods. The floating grinding unit is an electric grinding device. Multiple floating grinding units are fixedly installed on the crossbeam of the movable support at intervals according to the position of the pressure steel pipe stiffening ring.

2. The automatic grinding device for stiffening circumferential welds of pressure steel pipes according to claim 1, characterized in that: The movable support has fixing clips at both ends of the crossbeam for fixing the two ends of the pressure steel pipe; the fixing clips include folding arms that are perpendicularly connected and fixed to both ends of the support, and each folding arm is equipped with rollers for sliding limit when the pressure steel pipe opening rotates.

3. The automatic grinding device for stiffening circumferential welds of pressure steel pipes according to claim 1, characterized in that: The fixed bracket is supported and fixed to the base at both ends by diagonal braces.

4. The automatic grinding device for stiffening circumferential welds of pressure steel pipes according to claim 1, characterized in that: The hydraulic rod is driven to extend and retract by an electro-hydraulic servo lifting system mounted on the base; the electro-hydraulic servo lifting system includes a motor and a hydraulic pump driven by it, and the hydraulic pump is connected to the hydraulic rod through an oil pipe.

5. The automatic grinding device for stiffening circumferential welds of pressure steel pipes according to claim 1, characterized in that: The floating grinding unit includes a linkage controller, multiple fixed electric grinding wheels, and a spring support base.

6. The automatic grinding device for stiffening circumferential welds of pressure steel pipes according to claim 5, characterized in that: The main body of the linkage controller includes a programmable logic controller as the control core, and integrates a power supply module, a relay output unit and a human-machine interface; it also includes a control switch module and a status feedback unit.

7. The automatic grinding device for stiffening circumferential welds of pressure steel pipes according to claim 5, characterized in that: The fixed electric grinding machine includes a fixed wide-face abrasive wheel grinding head, the abrasive wheel being rigidly connected to the output shaft via a quick-release flange with a keyway positioning structure; it is equipped with a series-wound asynchronous motor, with a flange interface at the bottom, and is rigidly connected to a spring support seat via bolts.

8. The automatic grinding device for stiffening circumferential welds of pressure steel pipes according to claim 5, characterized in that: The spring support base is a double-spring assembly, with two springs symmetrically arranged on both sides of the grinding head in each group. A guide rod is installed inside the spring, and a limit block is set at the top of the guide rod. A threaded adjusting nut is equipped at the bottom of the spring. The initial compression of the spring is changed by rotating the nut to achieve the preset contact pressure. The bottom of the spring support base is connected to the movable bracket by a hinge, which can rotate ±15° around the horizontal axis and achieve ±200mm displacement along the axial direction of the bracket through a screw adjustment mechanism.

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