Online spiral welded pipe external weld seam full weld seam automatic grinding device and grinding method

Abstract

The invention relates to an online spiral welded pipe outer weld full weld seam automatic grinding device and grinding method, belonging to the technical field of spiral welded pipe weld seam grinding; the device comprises a base, an axial displacement slideway is provided on the base, a lifting mechanism is provided above the axial displacement slideway, a radial adjustment mechanism is provided above the lifting mechanism, a cylinder combination mechanism is provided above the radial adjustment mechanism, a cross slide, an angle adjustment mechanism and a push rod limiting mechanism are provided above the cylinder combination mechanism; a grinding mechanism is installed above the cross slide; the invention realizes continuous online automatic grinding of the steel pipe by arranging two sets of grinding devices on both sides of the spiral welded pipe; the position of the grinding mechanism can be adjusted along the axial, radial, height and angle directions of the spiral welded pipe, the full weld of the outer weld of different spiral welded pipes can be ground, and the remaining height of the weld after grinding can be stably controlled; the invention is provided with an automatic control mode and a manual control mode, and has the function of automatic grinding of the outer weld of the online pipe end.

Description

Technical Field

[0001] The invention relates to an online spiral welded pipe outer weld full weld seam automatic grinding device and grinding method, belonging to the technical field of spiral welded pipe weld seam grinding. Background Art

[0002] The production of spiral welded pipes is a continuous production process in which the coils are continuously bent, formed and welded along a spiral line. Usually, two inner and outer welds are produced during the production of spiral welded pipes. The steel pipes continuously produced online are cut on the production line according to a certain length, and then individual steel pipes are produced.

[0003] After the spiral welded pipe is welded, its outer weld needs to be fully automatically ground. The significance of grinding is:

[0004] 1. Grinding the excess height of the external weld is beneficial to the service life of the pipeline. The higher the weld of the spiral welded pipe, the more concentrated the stress at the weld. Therefore, too high a weld height will affect the service life and service safety of the pipeline.

[0005] 2. The reduction of the weld of the spiral welded pipe can effectively reduce the thickness of the subsequent 3PE external anti-corrosion layer of the steel pipe, greatly reduce the use of external anti-corrosion materials, save resources, and enhance product competitiveness. The 3PE external anti-corrosion standard requirements for spiral welded pipes are: the thickness of the external anti-corrosion layer in the weld area shall not be less than 80% of the required thickness of the pipe body. When performing 3PE external anti-corrosion, the 3PE anti-corrosion layer is wound on the steel pipe in a spiral line with equal thickness in a softened state, and then passes through a series of rollers and continuously cooled to form a 3PE anti-corrosion layer on the steel pipe that is finally in a hardened state. The softened anti-corrosion layer is wound on the pipe body and the weld at the same time, so the roller squeezes and thins the anti-corrosion layer on the pipe body and the weld at the same time. Since the external weld is higher than the pipe body, the thinning effect of the roller on the external weld is stronger than that on the pipe body. The higher the height of the external weld and the worse the apparent state of the weld, the greater the thinning degree of the anti-corrosion layer at the external weld compared to the pipe body. Therefore, the height of the external weld is effectively reduced, the appearance of the external weld is improved, and while the thickness of the anti-corrosion layer at the weld is met, the consumption of the external anti-corrosion material of the pipe body is effectively reduced, thereby achieving the purpose of greatly saving the use of external anti-corrosion materials. From the test results, after the weld is repaired and polished, wrapping the 3PE external anti-corrosion layer for every million square meters can save at least more than two million yuan of external anti-corrosion materials. The annual output of external anti-corrosion materials of general anti-corrosion companies is at least hundreds of thousands to millions of square meters, so the economic benefits are significant.

[0006] As for the automatic grinding of the entire weld seam of the external weld seam of spiral welded pipes, there is currently no equipment for offline automatic grinding of the entire weld seam of the external weld seam of spiral welded pipes, and the development of online automatic grinding equipment for the entire weld seam of the external weld seam of spiral welded pipes is currently in the exploratory test stage. The significance of online automatic grinding of the entire weld seam of the external weld seam of spiral welded pipes is:

[0007] 1. It is very difficult to realize the automatic grinding of the entire weld seam of the external weld seam of the offline spiral welded pipe:

[0008] First, the diameter and weld state of each steel pipe vary randomly, so each steel pipe needs to be debugged during grinding;

[0009] Second, to transport the steel pipes in and out of the grinding equipment, a platform, a special roller table or a special trolley is required;

[0010] Third, when the grinding equipment moves in a straight line and the steel pipe rotates synchronously, the grinding position of the abrasive belt should be accurately matched with the spiral weld; or the grinding position of the abrasive belt should be fixed, and the steel pipe should move and rotate at the same time to achieve accurate matching of the spiral weld with the grinding position; both methods require accurate tracking and feedback of the spiral weld, and then complete the real-time matching and adjustment of the grinding equipment and the steel pipe to achieve accurate matching of the grinding point with the spiral weld;

[0011] Fourth, the grinding equipment should be able to adapt to changes in pipe diameter, slight changes in pitch and their accumulation, changes in the relative position of the pipe body and the weld in the radial direction, and precise control of the grinding height to prevent damage to the parent material during grinding, and the start and stop mode of the full weld of each steel pipe, etc.;

[0012] The above reasons cause the structural design difficulty of this large inertia offline spiral welded pipe external weld automatic grinding equipment to increase dramatically, the control is difficult to implement, the equipment is large and the cost is expensive. So far, there has been no successful offline spiral welded pipe external weld automatic grinding equipment developed and used.

[0013] 2. Online spiral weld external weld full weld grinding has several inherent advantages:

[0014] First, for each specification of steel pipe, you can choose to grind it at a fixed position: according to the production process characteristics of spiral welded pipe, when the pipe diameter, plate thickness and working width are determined, the pitch of the steel pipe, the length of the spiral line and the distance between the weld at any pitch position and the inner and outer welding points can be determined and are fixed values, so the position of the grinding weld can be fixed;

[0015] Second, according to the forming process of spiral welded pipe production, it is possible to eliminate various influencing factors through reasonable equipment function design;

[0016] Third, since the equipment performs grinding before the steel pipe is cut, continuous automatic grinding can be achieved after it is adjusted into place once. Summary of the invention

[0017] In view of the above deficiencies in the prior art, the technical problem to be solved by the present invention is: to provide an online spiral welded pipe external weld full weld automatic grinding device and grinding method, which can realize continuous online automatic grinding of the full weld of the external weld of spiral welded pipes with different diameters, plate thicknesses and working plate widths, thereby extending the service life of the spiral welded pipe, ensuring the service safety of the spiral welded pipe, reducing the use of anti-corrosion materials on the outside of the spiral welded pipe, and saving costs.

[0018] The online spiral welded pipe outer weld full weld seam automatic grinding device of the present invention comprises a base, an axial displacement slideway is arranged on the base, and the axial displacement slideway is arranged along the axial direction of the spiral welded pipe; it also comprises a lifting mechanism, a radial adjustment mechanism, a cylinder combination mechanism, an angle adjustment mechanism and a push rod limiting mechanism; the lifting mechanism is arranged on the axial displacement slideway, and the lifting mechanism can move along the axial displacement slideway; the radial adjustment mechanism is arranged above the lifting mechanism, and the radial adjustment mechanism is used to realize the displacement of the device at a larger radial distance of the spiral welded pipe to adapt to the change of the pipe diameter; the cylinder combination mechanism is arranged on the radial adjustment mechanism The cylinder combination mechanism can drive the mechanism above it to move; an angle adjustment mechanism and a push rod limiting mechanism are arranged above the cylinder combination mechanism; a cross slide is also arranged above the cylinder combination mechanism, and a grinding mechanism is installed above the cross slide; the grinding mechanism is a sanding belt machine; the cross slide can finely adjust the position of the grinding mechanism along the radial and axial directions of the spiral welded pipe, and the push rod limiting mechanism can be independently telescopically adjusted to effectively control the height of the weld after grinding; the angle adjustment mechanism is used to adjust the parallelism between the front end of the sanding belt of the grinding mechanism and the outer wall of the steel pipe, so as to adjust the uniformity of the remaining height of the weld after grinding.

[0019] Preferably, the radial adjustment mechanism includes a radial adjustment bracket and a radial adjustment pressure plate, the radial adjustment pressure plates are symmetrically arranged on both sides of the radial adjustment bracket, the radial adjustment pressure plates are fixed on the top plate of the lifting mechanism, the radial adjustment pressure plates on both sides are surrounded to form a movable groove, and the bottom of the radial adjustment bracket can move in the movable groove; the radial adjustment bracket is transmission-connected to the radial adjustment screw assembly; the bearing seat of the radial adjustment screw assembly is fixed on the top plate of the lifting mechanism; rotating the handwheel of the radial adjustment screw assembly can drive the radial adjustment bracket to move in the movable groove; the radial adjustment pressure plate is also provided with a radial locking handle.

[0020] Preferably, the cylinder assembly mechanism comprises a lower mounting plate of the cylinder assembly mechanism, the lower mounting plate of the cylinder assembly mechanism is threadedly connected to the radial adjustment bracket, a cylinder fixing plate is fixed to one end of the lower mounting plate of the cylinder assembly mechanism, the rear end of the cylinder is fixedly connected to the cylinder fixing plate, the head end of the cylinder is fixedly connected to the front end vertical plate, the front end vertical plate is fixedly connected to the upper mounting plate of the cylinder assembly mechanism, the upper mounting plate of the cylinder assembly mechanism is slidably connected to the lower mounting plate of the cylinder assembly mechanism through a guide rail slider assembly, and the cylinder can drive the upper mounting plate of the cylinder assembly mechanism to move radially along the spiral welded pipe;

[0021] A plurality of movable top blocks are provided on both sides of the lower mounting plate of the cylinder combination mechanism. The movable top blocks are connected to the lower mounting plate of the cylinder combination mechanism by bolts, and the center threads of the movable top blocks are connected to the lifting balls. When adjustment is required, the bolts between the lower mounting plate of the cylinder combination mechanism and the radial adjustment bracket can be removed, and the lower mounting plate of the cylinder combination mechanism can be lifted up by adjusting the lifting balls, so as to facilitate manual radial displacement adjustment over a larger range.

[0022] Preferably, the cross slide comprises an angle adjustment plate, an axial dovetail seat, an adapter seat and a radial dovetail seat; the angle adjustment plate is rotatably connected to the mounting plate on the cylinder assembly mechanism through a rotating shaft, and is locked in position with the mounting plate on the cylinder assembly mechanism after being rotated into place; the axial dovetail seat is fixedly connected above the angle adjustment plate, and an adapter seat is arranged above the axial dovetail seat, and the axial dovetail seat is slidably connected to the adapter seat through a dovetail groove at the bottom of the adapter seat; an axial fine-tuning screw mechanism is also installed on the axial dovetail seat, and is transmission-connected to the adapter seat through the axial fine-tuning screw mechanism; the precise axial position adjustment and alignment of the weld grinding can be achieved through the axial fine-tuning screw mechanism, and at the same time, the part of the abrasive belt that is not involved in the grinding in the width direction of the abrasive belt can be brought into the grinding position, so as to achieve full utilization of the abrasive belt;

[0023] The top of the adapter is slidably connected to the radial dovetail seat through a dovetail groove, and the radial dovetail seat is transmission-connected to the adapter through a radial fine-tuning screw mechanism; the radial and axial positions of the grinding mechanism can be fine-tuned by adjusting the handwheels of the radial fine-tuning screw mechanism and the axial fine-tuning screw mechanism.

[0024] Preferably, the angle adjustment mechanism includes a fixed shaft, an internally threaded sleeve and a rotating block; the fixed shaft is fixedly connected to the mounting plate on the cylinder combination mechanism, a joint bearing is sleeved on the fixed shaft, the joint bearing is threadedly connected to the internally threaded sleeve, the internally threaded sleeve is rotatably connected to the rotating block, the bottom of the rotating block is rotatably connected to the angle adjustment connecting plate, and the angle adjustment connecting plate is fixedly connected to the angle adjustment plate; an arc groove for adjustment is provided on the angle adjustment plate; an angle adjustment handwheel is installed at the end of the internally threaded sleeve, and rotating the angle adjustment handwheel can drive the internally threaded sleeve to rotate, and the angle adjustment plate is pushed to rotate around the rotating axis with the help of the reaction force of the joint bearing, and the locking screw is used to quickly lock the angle after the angle is adjusted.

[0025] Preferably, the push rod limiting mechanism comprises a limiting mechanism mounting frame, a limiting rod is mounted on the limiting mechanism mounting frame, a limiting bull's eye bearing is fixed to the front end of the limiting rod; the position of the limiting rod on the limiting mechanism mounting frame is adjustable.

[0026] Preferably, lifting bull's eye bearings are provided at the four corners below the lifting mechanism. By adjusting the lifting bull's eye bearings, the bottom surface of the lifting mechanism can be separated from the axial displacement slideway, so as to facilitate the movement of the lifting mechanism, so that the sanding belt of the grinding mechanism is aligned with the weld to be ground, and it can be suitable for spiral welded pipes with different pitches and avoid interference with existing equipment on the production line. After adjusting the position, the lifting mechanism and the axial displacement slideway can be locked by bolts.

[0027] Preferably, the online spiral welded pipe outer weld full weld automatic grinding device also includes a dust collection device, the dust collection device includes a combined adjustable dust hood and a dust box, the combined adjustable dust hood is hinged at the bottom of the grinding mechanism, the combined adjustable dust hood can be extended and retracted according to the requirements of different pipe diameters to collect dust, and the splashes sprayed by the fan-shaped surface are effectively collected in the dust box; the dust box is located below the combined adjustable dust hood, and a roller for easy movement is provided at the bottom of the dust box; a combined adjustable dust hood support roller is installed on the side of the lower mounting plate of the cylinder combination mechanism close to the spiral welded pipe, and the position of the combined adjustable dust hood support roller can be adjusted along the radial direction of the spiral welded pipe, and when the cylinder retracts and extends, the combined adjustable dust hood support roller rolls to support the combined adjustable dust hood, stably control the hinge angle, and then adjust the collection angle of the combined adjustable dust hood to ensure the dust collection efficiency.

[0028] The method for automatic grinding of the entire weld seam of the external weld seam of the spiral welded pipe described in the present invention comprises two sets of online automatic grinding devices for the entire weld seam of the external weld seam of the spiral welded pipe with the same structure, and the two sets of devices are distributed on both sides of the spiral welded pipe; the two sets of devices are mutually main and auxiliary, one set of devices is set as the main equipment, and the other set of devices is set as the auxiliary equipment, and the main function of the auxiliary equipment is to complete the grinding of the section of the external weld seam that is not ground during the replacement of the sanding belt of the main equipment, and specifically comprises the following steps:

[0029] S1. Position debugging of the grinding mechanism, specifically including the following steps:

[0030] S11. According to the different pitches and to avoid interference from existing equipment on the production line, adjust the position of the lifting mechanism on the axial displacement slideway so that the sanding belt of the grinding mechanism is aligned with the weld to be ground; adjust the two sets of automatic grinding devices to be spaced 0.5 times the pitch in the axial direction of the spiral welded pipe;

[0031] S12, adjust the lifting mechanism so that the axis of the grinding wheel of the grinding mechanism is at the same height as the axis of the spiral welded pipe;

[0032] S13, adjusting the radial position of the grinding mechanism along the spiral welded pipe: when the cylinder is in the retracted state, adjust the position of the limit bull's eye bearing so that the front end of the limit bull's eye bearing is separated from the outer wall of the spiral welded pipe at the 3 o'clock or 9 o'clock position by a certain distance, and the distance is less than the cylinder stroke; then adjust the radial fine-tuning screw mechanism of the cross slide separately to move the grinding mechanism toward the spiral welded pipe until the front end of the sand belt approaches the front end of the limit bull's eye bearing; then start the grinding mechanism and extend the linkage cylinder to drive the grinding mechanism and the limit bull's eye bearing to move forward as a whole, and the cylinder presses the front end of the limit bull's eye bearing on the outer wall of the spiral welded pipe with a stable pressure; continue to adjust the radial horizontal displacement of the cross slide separately so that the sand belt gradually approaches the weld of the steel pipe and enters the grinding state until the desired residual height of the weld is ground;

[0033] S14, adjusting the angle adjustment mechanism, the parallelism between the front end of the abrasive belt and the outer wall of the steel pipe can be adjusted, so as to adjust the uniformity of the remaining height of the weld after grinding, and the angle can be locked after adjustment;

[0034] S2. Grinding the weld of spiral welded pipe; the spiral production host starts, the coil is delivered along the spiral line, and the internal and external welds are started at the same time for fixed-point welding to form a spiral weld; the spiral production host has the function of real-time detection of welding length during production; the control programs of the two sets of online spiral welded pipe external weld full weld automatic grinding devices have two control modes: automatic control mode or manual control mode, and the control program has the function of reading welding length;

[0035] The automatic control mode does not need to consider which of the main equipment and the auxiliary equipment is closer to the external welding position of the spiral welded pipe. The design of the equipment structure can ensure that the repeated grinding of the second equipment will not have a significant impact on the height of the already ground weld. The automatic control mode specifically includes the following steps:

[0036] S2a-1, switch the control program to the automatic control mode, at this time, the two sets of online spiral welded pipe external weld seam full weld seam automatic grinding devices and the spiral production host are started and stopped online through the control program;

[0037] S2a-2, the main machine of spiral production is turned on, and the grinding mechanism of the main equipment is started. At this time, the linkage cylinder is pushed forward, and the cylinder drives the grinding mechanism to move forward until the limit bull's eye bearing is against the outer wall of the spiral welded pipe, and the sanding belt begins to grind the weld; after a few seconds, the coil is delivered along the spiral line, and the internal and external welding begins. At the same time, the control program begins to accumulate and record the welding length of the main machine weld;

[0038] S2a-3, when the welding length read by the control program reaches the set limit length of the grinding belt, the auxiliary equipment is automatically started to start grinding; when the welding length of the auxiliary equipment exceeds the spiral welding length of 0.75 times the pitch, the main equipment stops welding, and the grinding mechanism stops and the cylinder is linked to retreat, driving the grinding mechanism to retreat, and at the same time the control program stops accumulating welding length, and the main equipment grinding belt can be replaced;

[0039] S2a-4. After manually replacing the grinding belt of the main equipment, restart the grinding of the main equipment, and the control program restarts the accumulation of the grinding length of the grinding belt; when the grinding weld length of the main equipment exceeds 0.75 times the pitch spiral weld length, the auxiliary equipment automatically stops the weld grinding;

[0040] S2a-5. During the production process, when the spiral production host needs to be temporarily stopped, the spiral production host starts the shutdown bell. After a few seconds, the spiral production host stops internal and external welding. At this time, the main equipment stops welding seam grinding, and the control program automatically saves the accumulated grinding length;

[0041] S2a-6, when the main machine of the spiral production is restarted, the main equipment starts grinding again; the control program continues to accumulate the grinding length of the weld until the grinding length of the main equipment reaches the set grinding belt welding limit length; this cycle repeats; the grinding belt of the auxiliary equipment can be replaced at any time when the auxiliary equipment is not working;

[0042] The manual control mode specifically includes the following steps:

[0043] S2b-1, switch the control program to manual control mode, at which time the start and stop of the two sets of online spiral welded pipe external weld full weld seam automatic grinding devices are not affected by the start and stop of the spiral production host;

[0044] S2b-2. When the sanding belt of the main equipment needs to be replaced, if the auxiliary equipment is closer to the external welding position than the main equipment, first manually start the auxiliary equipment for automatic grinding. After the ground weld passes through the main equipment, the main equipment can be stopped at any time and the sanding belt can be replaced. After the sanding belt of the main equipment is replaced, the automatic grinding of the auxiliary equipment can be stopped;

[0045] S2b-3. If the main equipment is closer to the external welding position than the auxiliary equipment, after starting the auxiliary equipment for automatic grinding, the main equipment can be stopped at any time to replace the sanding belt. After replacing the sanding belt of the main equipment, the automatic grinding of the auxiliary equipment can be stopped;

[0046] S2b-4. The sanding belt of the auxiliary equipment can be replaced at any time as long as it is not involved in the operation; through the above-mentioned alternating operation, the automatic grinding of the entire weld seam outside the line can be realized;

[0047] S3. The control program is also provided with an automatic grinding mode for the outer weld of the online pipe end. When this mode is adopted, the automatic grinding device for the outer weld of the online spiral welded pipe is not connected to the start and stop of the spiral production host, but is controlled by two induction switches. Only one set of automatic grinding device for the outer weld of the online spiral welded pipe is adopted. Along the outlet direction of the spiral welded pipe, behind the grinding position of the grinding mechanism, at a distance equal to the length M of the fixed-length steel pipe, an induction switch is respectively set at the position of the distance N to be ground forward and backward. Specifically, the following steps are included:

[0048] S31, switching to the automatic grinding mode of the outer weld of the online pipe end;

[0049] S32. When the front end of the spiral welded pipe is detected by the first nearby induction switch, the online spiral welded pipe outer weld full weld automatic grinding device is started and the outer weld grinding begins. When the second induction switch detects the spiral welded pipe, the weld grinding stops automatically. When the steel pipe is cut to a fixed length, the grinding of the outer weld at the rear end of the previous steel pipe and the outer weld at the front end of the next steel pipe is completed.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1. The present invention provides two sets of grinding devices with the same structure on both sides of the spiral welded pipe. The two sets of grinding devices serve as the main and auxiliary devices for each other and perform grinding alternately, thereby realizing continuous online automatic grinding of the steel pipe.

[0052] 2. By setting up multiple sets of mechanisms that can be adjusted along the axial, radial, height and angle directions of the spiral welded pipe, the position of the grinding mechanism can be adjusted, and the entire weld seam of the outer weld seam of the spiral welded pipe with different diameters, plate thicknesses and working plate widths can be ground, and the remaining height of the weld seam after grinding can be stably controlled in conjunction with the ejector rod limiting mechanism to ensure the consistency of the remaining height of the weld seam after grinding and the consistency of the appearance shape;

[0053] 3. The present invention is provided with an automatic control mode and a manual control mode, and also has the function of automatic grinding of the outer weld of the online pipe end, which is convenient and quick to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a schematic diagram of the state of the present invention when it is working;

[0055] Figure 2 It is the front view of the present invention when it is working;

[0056] Figure 3 It is one of the structural schematic diagrams of the device of the present invention;

[0057] Figure 4 This is the second structural schematic diagram of the device of the present invention;

[0058] Figure 5 It is a structural diagram of the base and the lifting mechanism;

[0059] Figure 6 It is a sectional view of the main view of the base and lifting mechanism;

[0060] Figure 7 It is a structural schematic diagram of the radial adjustment mechanism;

[0061] Figure 8 It is a structural diagram of the cylinder combination mechanism;

[0062] Fig. 9 It is a sectional view of the main view of the cylinder assembly mechanism;

[0063] Fig.10 It is a structural schematic diagram of the ejector rod limiting mechanism;

[0064] Fig.11 It is a structural diagram of the cross slide;

[0065] Fig.12 is a structural schematic diagram of the angle adjustment mechanism;

[0066] Fig.13 It is a structural schematic diagram of a dust collecting device.

[0067] In the figure: 1. Automatic grinding device for the entire weld seam of the outer weld seam of the online spiral welded pipe; 11. Base; 111. Axial displacement slideway; 12. Lifting mechanism; 121. Lifting bull's eye bearing; 13. Radial adjustment mechanism; 131. Radial adjustment screw assembly; 132. Radial adjustment pressure plate; 133. Radial locking handle; 134. Radial adjustment bracket; 14. Cylinder combination mechanism; 141. Cylinder combination mechanism upper mounting plate; 142. Cylinder fixing plate; 143. Moving top block; 144. Lifting ball; 145. Combined adjustment of dust cover support roller; 146. Cylinder combination mechanism lower mounting plate; 147. Front end vertical plate; 148. Cylinder; 149. Guide rail slider assembly; 15. Cross slide; 151. Axial dovetail seat; 152. Adapter seat; 153. Radial fine-tuning screw mechanism; 154. Radial dovetail seat; 155. Axial fine-tuning screw mechanism; 156. Angle adjustment plate; 157. Rotating shaft; 158. Locking screw; 16. Grinding mechanism; 17. Angle adjustment mechanism; 171. Spherical bearing; 172. Fixed shaft; 173. Internal threaded sleeve; 174. Rotating block; 175. Angle adjustment handwheel; 176. Angle adjustment connecting plate; 18. Dust collection device; 181. Dust collection box; 182. Combined adjustment dust cover; 19. Push rod limit mechanism; 191. Limit rod; 192. Limit bull's eye bearing; 193. Limit mechanism mounting bracket; 2. Spiral welded pipe. DETAILED DESCRIPTION

[0068] The present invention is further described below in conjunction with specific embodiments.

[0069] like Figures 1 to 13 As shown, this embodiment is implemented by the following technical solutions: it includes a base 11, an axial displacement slide 111 is provided on the base 11, the axial displacement slide 111 is arranged along the axial direction of the spiral welded pipe 2, a lifting mechanism 12 is provided above the axial displacement slide 111, the lifting mechanism 12 can move along the axial displacement slide 111, a radial adjustment mechanism 13 is provided above the lifting mechanism 12, and the radial adjustment mechanism 13 can realize the displacement of the device in the radial direction of the spiral welded pipe 2 by a large distance to adapt to the change of the pipe diameter; a cylinder group is provided above the radial adjustment mechanism 13 A cross slide 15, an angle adjustment mechanism 17 and a push rod limiting mechanism 19 are arranged above the cylinder combination mechanism 14; a grinding mechanism 16 is installed above the cross slide 15, and the cross slide 15 can finely adjust the position of the grinding mechanism 16 along the radial and axial directions of the spiral welded pipe 2, and the push rod limiting mechanism 19 can be independently telescopically adjusted to effectively control the height of the weld after grinding; the angle adjustment mechanism 17 is used to adjust the parallelism between the front end of the sanding belt of the grinding mechanism 16 and the outer wall of the steel pipe, so as to adjust the uniformity of the remaining height of the weld after grinding.

[0070] In this embodiment, the radial adjustment mechanism 13 includes a radial adjustment bracket 134 and a radial adjustment pressure plate 132. The radial adjustment pressure plates 132 are symmetrically arranged on both sides of the radial adjustment bracket 134. The radial adjustment pressure plates 132 are fixed to the top plate of the lifting mechanism 12. The radial adjustment pressure plates 132 on both sides are surrounded to form a movable groove, and the bottom of the radial adjustment bracket 134 moves in the movable groove; the radial adjustment bracket 134 is transmission-connected with the radial adjustment screw assembly 131; the bearing seat of the radial adjustment screw assembly 131 is fixed to the top plate of the lifting mechanism 12; rotating the handwheel of the radial adjustment screw assembly 131 can drive the radial adjustment bracket 134 to move in the movable groove; the radial adjustment pressure plate 132 is also provided with a radial locking handle 133.

[0071] The cylinder assembly mechanism 14 comprises a lower mounting plate 146 of the cylinder assembly mechanism, which is threadedly connected to the radial adjustment bracket 134, a cylinder fixing plate 142 is fixed to one end of the lower mounting plate 146 of the cylinder assembly mechanism, a rear end of the cylinder 148 is fixedly connected to the cylinder fixing plate 142, a head end of the cylinder 148 is connected to a front end vertical plate 147, and the front end vertical plate 147 is fixedly connected to an upper mounting plate 141 of the cylinder assembly mechanism; the upper mounting plate 141 of the cylinder assembly mechanism is slidably connected to the lower mounting plate 146 of the cylinder assembly mechanism through a guide rail slider assembly 149, and the cylinder 148 can drive the upper mounting plate 141 of the cylinder assembly mechanism to move radially along the spiral welded pipe 2;

[0072] A plurality of movable top blocks 143 are provided on both sides of the lower mounting plate 146 of the cylinder combination mechanism. The movable top blocks 143 are connected to the lower mounting plate 146 of the cylinder combination mechanism by bolts, and the center thread of the movable top block 143 is connected to the lifting ball 144. When adjustment is required, the bolts between the lower mounting plate 146 of the cylinder combination mechanism and the radial adjustment bracket 134 can be removed, and the lower mounting plate 146 of the cylinder combination mechanism can be lifted up by adjusting the lifting ball 144, so as to facilitate manual radial displacement adjustment in a larger range.

[0073] The cross slide 15 includes an angle adjustment plate 156, an axial dovetail seat 151, an adapter seat 152 and a radial dovetail seat 154; the angle adjustment plate 156 is rotatably connected to the mounting plate 141 on the cylinder assembly mechanism through a rotating shaft 157, and is locked in position with the mounting plate 141 on the cylinder assembly mechanism after being rotated into place; the axial dovetail seat 151 is fixedly connected to the top of the angle adjustment plate 156, and an adapter seat 152 is arranged above the axial dovetail seat 151, and the axial dovetail seat 151 is slidably connected to the dovetail groove at the bottom of the adapter seat 152; an axial fine-tuning screw mechanism 155 is also installed on the axial dovetail seat 151 ... The axial fine-tuning screw mechanism 155 is transmission-connected with the adapter 152; the axial fine-tuning screw mechanism 155 can realize precise axial position adjustment and alignment of the weld grinding, and at the same time, the part of the abrasive belt that does not participate in grinding in the width direction of the abrasive belt can be brought into the grinding position to realize full utilization of the abrasive belt; the top of the adapter 152 is slidingly connected to the radial dovetail seat 154 through a dovetail groove, and the radial dovetail seat 154 is transmission-connected with the adapter 152 through a radial fine-tuning screw mechanism 153; the radial and axial positions of the grinding mechanism 16 can be fine-tuned by adjusting the handwheels of the radial fine-tuning screw mechanism 153 and the axial fine-tuning screw mechanism 155.

[0074] The angle adjustment mechanism 17 comprises a fixed shaft 172, an internally threaded sleeve 173 and a rotating block 174; the fixed shaft 172 is fixedly connected to the mounting plate 141 on the cylinder assembly mechanism, a spherical bearing 171 is sleeved on the fixed shaft 172, the spherical bearing 171 is threadedly connected to the internally threaded sleeve 173, the internally threaded sleeve 173 is rotatably connected to the rotating block 174, the bottom of the rotating block 174 is rotatably connected to an angle adjustment connecting plate 176, and the angle adjustment connecting plate 176 is fixedly connected to the angle adjustment plate 156; an arc notch for adjustment is provided on the angle adjustment plate 156; an angle adjustment hand wheel 175 is installed at the end of the internally threaded sleeve 173, and rotating the angle adjustment hand wheel 175 can drive the internally threaded sleeve 173 to rotate, and the angle adjustment plate 156 is pushed to rotate around the rotating shaft 157 by the reaction force of the spherical bearing 171, and the locking screw 158 is used to quickly lock the angle after the angle is adjusted.

[0075] The push rod limiting mechanism 19 comprises a limiting mechanism mounting frame 193, on which a limiting rod 191 is mounted, and a limiting bull's eye bearing 192 is fixed at the head end of the limiting rod 191; the position of the limiting rod 191 on the limiting mechanism mounting frame 193 is adjustable.

[0076] Lifting bull's eye bearings 121 are provided at the four corners below the lifting mechanism 12. By adjusting the lifting bull's eye bearings 121, the bottom surface of the lifting mechanism 12 can be separated from the axial displacement slide 111, so as to facilitate the movement of the lifting mechanism 12, so that the sanding belt of the grinding mechanism 16 is aligned with the weld to be repaired, and it can be suitable for spiral welded pipes with different pitches and avoid interference with existing equipment on the production line; after adjusting the position, the lifting mechanism 12 and the axial displacement slide 111 can be locked by bolts.

[0077] The online spiral welded pipe outer weld full weld seam automatic grinding device 1 also includes a dust collecting device 18, which includes a combined adjustable dust collecting hood 182 and a dust collecting box 181. The combined adjustable dust collecting hood 182 is hinged below the grinding mechanism 16. The combined adjustable dust collecting hood 182 can be retracted and retracted to collect dust according to the requirements of different pipe diameters, and the splashes sprayed by the fan are effectively collected in the dust collecting box 181; the dust collecting box 181 is located below the combined adjustable dust collecting hood 182, and a roller for easy movement is provided at the bottom of the dust collecting box 181; a combined adjustable dust collecting hood support roller 145 is installed on one side of the lower mounting plate 146 of the cylinder combination mechanism close to the spiral welded pipe 2, and the position of the combined adjustable dust collecting hood support roller 145 can be adjusted along the radial direction of the spiral welded pipe. When the cylinder 148 retracts and extends, the combined adjustable dust collecting hood support roller 145 rolls and supports the combined adjustable dust collecting hood 182, stably controls the hinge angle, and then adjusts the collection angle of the combined adjustable dust collecting hood 182 to ensure the dust collection efficiency.

[0078] The method for automatic grinding of the entire weld seam of the external weld seam of the online spiral welded pipe described in this embodiment comprises two sets of online automatic grinding devices 1 for the entire weld seam of the external weld seam of the spiral welded pipe with the same structure, and the two sets of devices are distributed on both sides of the spiral welded pipe 2; the two sets of devices are mutually main and auxiliary, one set of devices is set as the main equipment, and the other set of devices is set as the auxiliary equipment, and the main function of the auxiliary equipment is to complete the grinding of the section of the external weld seam that is not ground during the replacement of the sanding belt of the main equipment, and specifically comprises the following steps:

[0079] S1, position debugging of the grinding mechanism 16, specifically including the following steps:

[0080] S11. According to the different pitches and to avoid interference from existing equipment on the production line, adjust the position of the lifting mechanism 12 on the axial displacement slideway 111 so that the abrasive belt of the grinding mechanism 16 is aligned with the weld to be ground; adjust the two sets of online spiral welded pipe external weld full weld seam automatic grinding devices 1 to be axially spaced 0.5 times the pitch of the spiral welded pipe 2;

[0081] S12, adjusting the lifting mechanism 12 so that the axis of the grinding wheel of the grinding mechanism 16 is at the same height as the axis of the spiral welded pipe 2;

[0082] S13, adjust the radial position of the grinding mechanism 16 along the spiral welded pipe: when the cylinder 148 is in the retracted state, adjust the position of the limit bull's eye bearing 192 so that the front end of the limit bull's eye bearing 192 is separated from the outer wall of the spiral welded pipe 2 at the 3 o'clock or 9 o'clock position by a certain distance, and the distance is less than the stroke of the cylinder 148; then adjust the radial fine-tuning screw mechanism 153 of the cross slide 15 separately to move the grinding mechanism 16 toward the spiral welded pipe 2 until the front end of the sand belt approaches the front end of the limit bull's eye bearing 192; then start the grinding mechanism 16 and extend the linkage cylinder 148 to drive the grinding mechanism 16 and the limit bull's eye bearing 192 to move forward as a whole, and the cylinder 148 presses the front end of the limit bull's eye bearing 192 on the outer wall of the spiral welded pipe 2 with a stable pressure; continue to adjust the radial horizontal displacement of the cross slide 15 separately so that the sand belt gradually approaches the steel pipe weld and enters the grinding state until the desired weld residual height is ground;

[0083] S14, adjusting the angle adjustment mechanism 17, which can adjust the parallelism between the front end of the abrasive belt and the outer wall of the steel pipe, thereby adjusting the uniformity of the remaining height of the weld after grinding, and locking the angle after adjustment;

[0084] S2, grinding the weld of the spiral welded pipe 2; the spiral production host is started, the coil is rolled and delivered along the spiral line, and the internal and external welds are started at the same time for fixed-point welding to form a spiral weld; the spiral production host has the function of real-time detection of welding length during production; the control program of the two sets of online spiral welded pipe external weld full weld automatic grinding devices 1 has two control modes: automatic control mode or manual control mode, and the control program has the function of reading the welding length;

[0085] The automatic control program does not need to consider which of the main equipment and the auxiliary equipment is closer to the external welding position of the spiral welded pipe 2. The design of the equipment structure can ensure that the repeated grinding of the second equipment will not have a significant impact on the height of the already ground weld. The automatic control mode specifically includes the following steps:

[0086] S2a-1, switching the control program to the automatic control mode, at this time, the two sets of online spiral welded pipe external weld full weld seam automatic grinding devices 1 and the spiral production host are started and stopped online through the control program;

[0087] S2a-2, the main machine of the spiral production is turned on, and the grinding mechanism 16 of the main equipment is started. At this time, the linkage cylinder 148 is pushed forward, and the cylinder 148 drives the grinding mechanism 16 to move forward until the limit bull's eye bearing 192 is pressed against the outer wall of the spiral welded pipe 2, and the abrasive belt begins to grind the weld; after a few seconds, the coil is delivered along the spiral line, and the internal and external welding begins. At the same time, the control program begins to accumulate and record the welding length of the main machine weld;

[0088] S2a-3, when the welding length read by the control program reaches the set limit length of the grinding belt, the auxiliary equipment is automatically started to start grinding; when the welding length of the auxiliary equipment exceeds the spiral welding length of 0.75 times the pitch, the main equipment stops welding, and the grinding mechanism 16 stops and the cylinder 148 is linked to retreat, driving the grinding mechanism 16 to retreat, and at the same time the control program stops accumulating welding length, and the main equipment grinding belt can be replaced;

[0089] S2a-4. After manually replacing the grinding belt of the main equipment, restart the grinding of the main equipment, and the control program restarts the accumulation of the grinding length of the grinding belt; when the grinding weld length of the main equipment exceeds 0.75 times the pitch spiral weld length, the auxiliary equipment automatically stops the weld grinding;

[0090] S2a-5. During the production process, when the spiral production host needs to be temporarily stopped, the spiral production host starts the shutdown bell. After a few seconds, the spiral production host stops internal and external welding. At this time, the main equipment stops welding seam grinding, and the control program automatically saves the accumulated grinding length;

[0091] S2a-6, when the main machine of the spiral production is restarted, the main equipment starts grinding again; the control program continues to accumulate the grinding length of the weld until the grinding length of the main equipment reaches the set grinding belt welding limit length; this cycle repeats; the grinding belt of the auxiliary equipment can be replaced at any time when the auxiliary equipment is not working;

[0092] The manual control mode specifically includes the following steps:

[0093] S2b-1, switch the control program control to manual control mode, at this time, the start and stop of the two sets of online spiral welded pipe external weld full weld seam automatic grinding devices 1 are not affected by the start and stop of the spiral production host;

[0094] S2b-2. When the sanding belt of the main equipment needs to be replaced, if the auxiliary equipment is closer to the external welding position than the main equipment, first manually start the auxiliary equipment for automatic grinding. After the ground weld passes through the main equipment, the main equipment can be stopped at any time and the sanding belt can be replaced. After the sanding belt of the main equipment is replaced, the automatic grinding of the auxiliary equipment can be stopped;

[0095] S2b-3. If the main equipment is closer to the external welding position than the auxiliary equipment, after starting the auxiliary equipment for automatic grinding, the main equipment can be stopped at any time to replace the sanding belt. After replacing the sanding belt of the main equipment, the automatic grinding of the auxiliary equipment can be stopped;

[0096] S2b-4. The sanding belt of the auxiliary equipment can be replaced at any time as long as it is not involved in the operation; through the above-mentioned alternating operation, the automatic grinding of the entire weld seam outside the line can be realized;

[0097] S3. The control program is also provided with an online pipe end outer weld automatic grinding mode. When this mode is adopted, the online spiral welded pipe outer weld full weld automatic grinding device 1 is not connected to the start and stop of the spiral production host, but is controlled by two induction switches. It can be realized by only one set of online spiral welded pipe outer weld full weld automatic grinding device 1. For example, a cut-to-length steel pipe with a length of 12 meters and a pipe end grinding length of 300mm is cut. Along the outlet direction of the spiral welded pipe 2, behind the grinding position of the grinding mechanism 16, at a distance of 12 meters, an induction switch is respectively set at a distance of 300mm forward and backward, and the following steps are specifically included:

[0098] S31, switching to the automatic grinding mode of the outer weld of the online pipe end;

[0099] S32. When the front end of the spiral welded pipe 2 is detected by the first nearby induction switch, the online spiral welded pipe outer weld full weld automatic grinding device 1 is started and the outer weld grinding begins. When the second induction switch detects the spiral welded pipe 2, the weld grinding stops automatically. When the steel pipe is cut to a fixed length of 12 meters, the grinding of the outer weld at the rear end of the previous steel pipe and the outer weld at the front end of the next steel pipe is completed.

[0100] The invention can manually start and stop the equipment at any time according to the needs to grind the outer weld of the pipe end of the non-fixed-length steel pipe.

Claims

1. An online spiral welded pipe external weld full weld seam automatic grinding device, characterized in that: It comprises a base (11), on which an axial displacement slideway (111) is provided, and the axial displacement slideway (111) is arranged along the axial direction of the spiral welded pipe (2); It also includes a lifting mechanism (12), a radial adjustment mechanism (13), a cylinder combination mechanism (14), an angle adjustment mechanism (17) and a push rod limiting mechanism (19); The lifting mechanism (12) is arranged on the axial displacement slideway (111), and the lifting mechanism (12) can move along the axial displacement slideway (111); The radial adjustment mechanism (13) is arranged above the lifting mechanism (12), and the radial adjustment mechanism (13) is used to achieve displacement of the device over a relatively large radial distance of the spiral welded pipe (2); The cylinder assembly mechanism (14) is arranged above the radial adjustment mechanism (13), and the cylinder assembly mechanism (14) can drive the mechanism above it to move; An angle adjustment mechanism (17) and a push rod limiting mechanism (19) are provided above the cylinder assembly mechanism (14); A cross slide (15) is also provided above the cylinder assembly mechanism (14), and a grinding mechanism (16) is installed above the cross slide (15); The radial adjustment mechanism (13) comprises a radial adjustment bracket (134) and a radial adjustment pressure plate (132), wherein the radial adjustment pressure plates (132) are symmetrically arranged on both sides of the radial adjustment bracket (134), the radial adjustment pressure plates (132) are fixed to the top plate of the lifting mechanism (12), the radial adjustment pressure plates (132) on both sides surround and form a movable groove, and the bottom of the radial adjustment bracket (134) can move in the movable groove; the radial adjustment bracket (134) is transmission-connected to the radial adjustment screw assembly (131); The cylinder assembly mechanism (14) comprises a cylinder assembly mechanism lower mounting plate (146), the cylinder assembly mechanism lower mounting plate (146) is threadedly connected to the radial adjustment bracket (134), a cylinder fixing plate (142) is fixed to one end of the cylinder assembly mechanism lower mounting plate (146), the rear end of the cylinder (148) is fixedly connected to the cylinder fixing plate (142), the front end of the cylinder (148) is connected to the front end vertical plate (147), the front end vertical plate (147) is fixedly connected to the cylinder assembly mechanism upper mounting plate (141), and the cylinder assembly mechanism upper mounting plate (141) is slidably connected to the cylinder assembly mechanism lower mounting plate (146) via a guide rail slider assembly (149); The cross slide (15) comprises an angle adjustment plate (156), an axial dovetail seat (151), an adapter seat (152) and a radial dovetail seat (154); the angle adjustment plate (156) is rotatably connected to the mounting plate (141) on the cylinder assembly mechanism via a rotating shaft (157), and is locked in position with the mounting plate (141) on the cylinder assembly mechanism after being rotated into place; the upper part of the angle adjustment plate (156) is fixedly connected to the axial dovetail seat (151), the adapter seat (152) is arranged above the axial dovetail seat (151), and the axial dovetail seat (151) is slidably connected to the adapter seat (152) via a dovetail groove at the bottom of the adapter seat (152); The push rod limiting mechanism (19) comprises a limiting mechanism mounting frame (193), a limiting rod (191) is mounted on the limiting mechanism mounting frame (193), and a limiting bull's eye bearing (192) is fixed to the front end of the limiting rod (191).

2. The online spiral welded pipe outer weld full weld seam automatic grinding device according to claim 1 is characterized in that: The device also comprises a dust collecting device (18), the dust collecting device (18) comprising a combined adjustable dust collecting cover (182) and a dust collecting box (181), the combined adjustable dust collecting cover (182) being hingedly connected to the bottom of the grinding mechanism (16), the dust collecting box (181) being located below the combined adjustable dust collecting cover (182), and a roller for facilitating movement being provided at the bottom of the dust collecting box (181).

3. The online spiral welded pipe outer weld full weld seam automatic grinding device according to claim 2 is characterized in that: The grinding mechanism (16) is a belt sander.

4. An automatic grinding method using the online spiral welded pipe external weld full weld automatic grinding device according to claim 3, characterized in that: The invention comprises two sets of online spiral welded pipe external weld seam full weld seam automatic grinding devices (1) with the same structure, the two sets of online spiral welded pipe external weld seam full weld seam automatic grinding devices (1) are distributed on both sides of the spiral welded pipe (2); the two sets of devices are mutually main and auxiliary, one set of devices is set as the main equipment, and the other set of devices is set as the auxiliary equipment, and specifically comprises the following steps: S1, position adjustment of the grinding mechanism (16), specifically comprising the following steps: S11. According to the different pitches and to avoid interference from existing equipment on the production line, the position of the lifting mechanism (12) on the axial displacement slideway (111) is adjusted so that the abrasive belt of the grinding mechanism (16) is aligned with the weld to be ground; two sets of online spiral welded pipe external weld full weld seam automatic grinding devices (1) are adjusted to be spaced 0.5 times the pitch in the axial direction of the spiral welded pipe (2); S12, adjusting the lifting mechanism (12) so that the axis of the grinding wheel of the grinding mechanism (16) is at the same height as the axis of the spiral welded pipe (2); S13, adjusting the radial position of the grinding mechanism (16) along the spiral welded pipe (2): when the cylinder (148) is in the retracted state, adjusting the position of the limit bull's eye bearing (192) so that the front end of the limit bull's eye bearing (192) is separated from the outer wall of the spiral welded pipe (2) at the 3 o'clock or 9 o'clock position by a certain distance, and the distance is less than the stroke of the cylinder (148); then adjusting the radial fine-tuning screw mechanism (153) of the cross slide (15) separately, so that the grinding mechanism (16) moves in the direction of the spiral welded pipe (2) until The front end of the sanding belt approaches the front end of the limit bull's eye bearing (192); then the grinding mechanism (16) is started and the cylinder (148) is extended, driving the grinding mechanism (16) and the limit bull's eye bearing (192) to move forward as a whole, and the cylinder (148) causes the front end of the limit bull's eye bearing (192) to be pressed against the outer wall of the spiral welded pipe (2) with a stable pressure; the radial horizontal displacement of the cross slide (15) is continuously adjusted separately, so that the sanding belt gradually approaches the weld of the steel pipe and enters the grinding state until the desired residual height of the weld is ground; S14, adjusting the angle adjustment mechanism (17), which can adjust the parallelism between the front end of the abrasive belt and the outer wall of the steel pipe, thereby adjusting the uniformity of the remaining height of the weld after grinding, and locking the angle after adjustment; S2, grinding the weld of the spiral welded pipe (2); the spiral production host is started, the coil is rolled and delivered along the spiral line, and the internal and external welds are simultaneously started to perform fixed-point welding to form a spiral weld; the spiral production host has the function of real-time detection of the welding length during production; the control programs of the two sets of online spiral welded pipe external weld full weld automatic grinding devices (1) are provided with two control modes: automatic control mode or manual control mode, and the control program has the function of reading the welding length; S3. The control program is also provided with an online pipe end outer weld automatic grinding mode. When this mode is adopted, the online spiral welded pipe outer weld full weld automatic grinding device (1) is not connected to the start and stop of the spiral production host, but is controlled by two induction switches. Only one set of online spiral welded pipe outer weld full weld automatic grinding device (1) is used. Along the outlet direction of the spiral welded pipe (2), behind the grinding position of the grinding mechanism (16), at a distance equal to the length M of the fixed-length steel pipe, an induction switch is respectively set at the position of the distance N to be ground forward and backward. Specifically, the following steps are included: S31, switching to the automatic grinding mode of the outer weld of the online pipe end; S32. When the front end of the spiral welded pipe (2) is detected by the first sensor switch approaching, the online spiral welded pipe outer weld full weld automatic grinding device (1) is started and the outer weld grinding begins. When the second sensor switch detects the spiral welded pipe (2), the weld grinding automatically stops. When the steel pipe is cut to a fixed length, the grinding of the outer weld of the rear end of the previous steel pipe and the outer weld of the front end of the next steel pipe is completed.

5. The automatic grinding method of the online spiral welded pipe outer weld full weld automatic grinding device according to claim 4 is characterized in that: In step S2, the automatic control mode does not need to consider which of the main equipment and the auxiliary equipment is closer to the outer welding position of the spiral welded pipe (2). The design of the equipment structure can ensure that the repeated grinding of the second equipment will not have a significant impact on the height of the already ground weld. The automatic control mode specifically includes the following steps: S2a-1, switching the control program to the automatic control mode, at which time the two sets of online spiral welded pipe external weld seam full weld seam automatic grinding devices (1) and the spiral production host are started and stopped online through the program; S2a-2, the main machine of the spiral production is turned on, and the grinding mechanism (16) of the main equipment is started. At this time, the linkage cylinder (148) is pushed forward, and the cylinder (148) drives the grinding mechanism (16) to move forward until the limit bull's eye bearing (192) is pressed against the outer wall of the spiral welded pipe (2), and the abrasive belt begins to grind the weld. After a few seconds, the coil is delivered along the spiral line, and the internal and external welding begins. At the same time, the control program begins to accumulate and record the welding length of the main machine weld. S2a-3, when the welding length read by the control program reaches the set limit length of the weld to be ground by the abrasive belt, the auxiliary equipment is automatically started to start grinding; when the weld length ground by the auxiliary equipment exceeds the spiral weld length of 0.75 times the pitch, the main equipment stops grinding the weld, and the grinding mechanism (16) stops and the cylinder (148) is linked to retreat, driving the grinding mechanism (16) to retreat, and at the same time the control program stops accumulating the welding length, and the abrasive belt of the main equipment can be replaced; S2a-4. After manually replacing the grinding belt of the main equipment, restart the grinding of the main equipment, and the control program restarts the accumulation of the grinding length of the grinding belt; when the grinding weld length of the main equipment exceeds 0.75 times the pitch spiral weld length, the auxiliary equipment automatically stops the weld grinding; S2a-5. During the production process, when the spiral production host needs to be temporarily stopped, the spiral production host starts the shutdown bell. After a few seconds, the spiral production host stops internal and external welding. At this time, the main equipment stops welding seam grinding, and the control program automatically saves the accumulated grinding length; S2a-6. When the main spiral production machine is restarted, the main equipment starts grinding again; the control program continues to accumulate the weld grinding length until the main equipment grinding length reaches the set maximum length of the weld grinding with the abrasive belt; and this cycle repeats; the abrasive belt of the auxiliary equipment can be replaced at any time when the auxiliary equipment is not working.

6. The automatic grinding method of the online spiral welded pipe outer weld full weld automatic grinding device according to claim 4 is characterized in that: In step S2, the manual control mode includes the following steps: S2b-1, switching the control program to manual control mode, at which time the start and stop of the two sets of online spiral welded pipe external weld seam full weld seam automatic grinding devices (1) are not affected by the start and stop of the spiral production host machine; S2b-2. When the sanding belt of the main equipment needs to be replaced, if the auxiliary equipment is closer to the external welding position than the main equipment, first manually start the auxiliary equipment for automatic grinding. After the ground weld passes through the main equipment, the main equipment can be stopped at any time and the sanding belt can be replaced. After the sanding belt of the main equipment is replaced, the automatic grinding of the auxiliary equipment can be stopped; S2b-3. If the main equipment is closer to the external welding position than the auxiliary equipment, after starting the auxiliary equipment for automatic grinding, the main equipment can be stopped at any time to replace the sanding belt. After replacing the sanding belt of the main equipment, the automatic grinding of the auxiliary equipment can be stopped; S2b-4. The sanding belt of the auxiliary equipment can be replaced at any time as long as it is not involved in the operation; through the above-mentioned alternating operations, the automatic grinding of the entire weld seam outside the line can be achieved.

Images