CN116100070A

CN116100070A - Inner wall cutting device of polyethylene plastic steel winding pipe

Info

Publication number: CN116100070A
Application number: CN202310133849.5A
Authority: CN
Inventors: 牟其善; 刘可岭
Original assignee: Shunfang Pipes Co ltd
Current assignee: Shunfang Pipes Co ltd
Priority date: 2023-02-16
Filing date: 2023-02-16
Publication date: 2023-05-12

Abstract

The utility model provides an inner wall cutting device of polyethylene plastic steel winding pipe, including mount and the support that is used for placing the tubular product, the axle center position department at tubular product mount sets up central lead screw, install the cutting platform that can remove on the central lead screw, install rotatable milling cutter through ball bearing and rotating the cover on the cutting platform, when the cutting platform moves along central lead screw axial, milling cutter can synchronous rotation cut the inner wall of tubular product, the cutting platform walking is stable can not take place the skew in whole cutting process, and milling cutter passes through flexible adjustment mechanism and installs on milling cutter arm, can carry out quantitative cutting according to setting for thickness, and then guarantee cutting accuracy, whole device can be applicable to longer tubular product, can realize milling many times under reciprocating motion, guarantee the smoothness of tubular product inner wall.

Description

Inner wall cutting device of polyethylene plastic steel winding pipe

Technical Field

The invention relates to the technical field of pipe processing equipment, in particular to an inner wall cutting device of a polyethylene plastic steel winding pipe.

Background

In the field of plastic large-caliber pipe production, the extrusion molding process is limited to a certain extent, and the large-caliber pipe can be extruded directly by difficult processing equipment, particularly when the pipe wall is thicker, the large-caliber plastic pipe is more difficult to extrude directly, so that the large-caliber plastic pipe is produced by using a polyethylene strip or a plastic steel plate strip by adopting a spiral winding method.

The spiral winding process for manufacturing the large-caliber pipeline by using the polyethylene strips or the plastic steel plate strips has a fatal defect that in the spiral winding process, adjacent strips or the plastic steel plate strips are thermally bonded together by rubber materials, spiral rubber material bulges or concaves are inevitably formed on the inner wall of the pipeline, so that the roughness coefficient of the inner wall of the pipeline is obviously increased, the original unique advantages of smooth inner wall and smooth flow of the polyethylene pipeline are overcome, and the problem to be solved is how to uniformly and rapidly eliminate the roughness coefficient in the large-caliber plastic pipe.

Disclosure of Invention

The invention aims to provide an inner wall cutting device of a polyethylene plastic steel winding pipe, which is used for running in the axial direction of the inside of the pipe body and performing rotary cutting, ensuring the cutting speed and precision while keeping the running stability of the device, cutting the inner wall of the polyethylene pipe by a set thickness, ensuring the smoothness of the inner wall and solving the problems in the prior art.

The technical scheme adopted for solving the technical problems is as follows: the utility model provides an inner wall cutting device of polyethylene plastic steel winding pipe, including two tubular product mounts that arrange side by side, the bottom between two tubular product mounts is equipped with a plurality of tubular product supports, install in the tubular product mount with the axle center setting center screw, first guide wheel is installed to center screw's front end, tubular product mount front side is equipped with the screw support, set up on the screw support with center screw matched with location jack, install screw translation mechanism at center screw's rear end, screw translation mechanism can drive center screw horizontal migration and be close to or keep away from the screw support, all install the guide wheel support between tubular product mount and screw support and between tubular product mount and the screw translation mechanism, the cooperation is installed along axial displacement's cutting platform on the center screw, the flexible platform supporting roller is installed to the bottom of cutting platform, set up in the axial of center screw and is equipped with platform guide slot, be equipped with platform guide slot matched with guide block, still install inner wall cutting mechanism in the cutting platform, inner wall cutting mechanism is including having the milling cutter motor, install ball bearing between cutting platform and the center screw translation mechanism on the rear end, ball bearing's stator is fixed on cutting platform, ball bearing's stator is equipped with the milling cutter shell on the outer lane, and the ball bearing's the milling cutter can be rotated around the rotor is equipped with the milling cutter through the motor on the outer lane of rolling mill, the rolling mill is equipped with the milling cutter shell through the rolling mill on the rolling mill, the rolling mill shell is equipped with the rolling mill on the rolling mill of rolling mill and the milling sleeve is equipped with the milling cutter. The screw translation mechanism comprises a translation control console, a translation motor is arranged in the translation control console, a rubber roller which is in contact with the central screw is also arranged in the translation control console, an output shaft of the translation motor is connected with a rotating shaft of the rubber roller through a power transmission belt, and the rotation of the rubber roller can drive the central screw to horizontally move. The end part of the center lead screw, which extends out of the translation control console, is provided with a second guide wheel. The driving mechanism comprises a driven gear arranged on the rotating sleeve, a driving gear is arranged on an output shaft of the milling cutter motor, a plurality of meshed driving gears are arranged on the cutting platform, and the driving gears are respectively meshed with the driving gear and the driven gear. The screw thread is installed in the rotating sleeve through rotating locking mechanism, the rotating locking mechanism comprises a square groove formed in the rotating sleeve, the screw thread can be close to or far away from a central screw rod in the square groove, a locking rod capable of rotating relatively is installed in the screw thread, a handle is arranged at one end of the locking rod penetrating out of the rotating sleeve, a spring is sleeved on the periphery of the locking rod between the rotating sleeve and the handle, the spring always has a trend of enabling the screw thread to be far away from the central screw rod, a strip hole is formed in the rotating sleeve, a strip rod matched with the strip hole is arranged on the locking rod, the strip rod can enter the rotating sleeve through the strip hole, the screw thread is meshed on the central screw rod when the strip rod is located in the rotating sleeve, the strip rod and the strip hole are staggered, and the strip rod is locked in the rotating sleeve under the elastic action of the spring. A winch is arranged between the screw rod translation mechanism and the pipe fixing frame, and a recovery rope connected with the cutting platform is wound on a rotating shaft of the winch. The pipe fixing frame comprises two semicircular hoops, pipe fastening clamps are arranged in each semicircular hoop through telescopic rods, and pipe supporting rollers are further arranged on the pipe support. The telescopic adjusting mechanism comprises a first screw rod arranged on the milling cutter arm, a second screw rod is arranged on the milling cutter, an adjusting screw sleeve is arranged between the first screw rod and the second screw rod in a matched mode, the threads of the first screw rod and the threads of the second screw rod are opposite in rotation, and the milling cutter can be close to or far away from the milling cutter arm by rotating the adjusting screw sleeve.

The invention has the positive effects that: the invention relates to an inner wall cutting device of a polyethylene plastic steel winding pipe, which comprises a fixing frame and a bracket for placing a pipe, wherein a center screw is arranged at the axis position of the pipe fixing frame, a movable cutting platform is arranged on the center screw, a rotatable milling cutter is arranged on the cutting platform through a ball bearing and a rotating sleeve, when the cutting platform axially moves along the center screw, the milling cutter can synchronously rotate to cut the inner wall of the pipe, the cutting platform is stable in running and can not generate deflection in the whole cutting process, the milling cutter is arranged on a milling cutter arm through a telescopic adjusting mechanism, quantitative cutting can be performed according to a set thickness, the cutting precision is further ensured, the whole device can be suitable for longer pipes, repeated milling can be realized under reciprocating movement, and the smoothness of the inner wall of the pipe is ensured.

Drawings

FIG. 1 is a schematic three-dimensional structure of the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is an enlarged view of the cross-sectional view taken along line A-A in FIG. 2;

FIG. 4 is an enlarged view of the B-B cross-sectional view of FIG. 2;

FIG. 5 is a schematic view of the structure of the cutting deck;

FIG. 6 is an enlarged view of the cross-sectional view taken along line C-C in FIG. 5;

FIG. 7 is an enlarged view of a portion of I in FIG. 5;

FIG. 8 is a sectional view taken along the direction D-D in FIG. 7;

FIG. 9 is a schematic view of the structure of FIG. 7 with the threads separated from the center lead screw;

FIG. 10 is a schematic view of the center lead screw and cutting table not yet entering the tubular;

fig. 11 is a schematic view showing a state in which the center screw and the cutting table are inserted into the pipe.

Detailed Description

The invention relates to an inner wall cutting device of a polyethylene plastic steel winding pipe, as shown in fig. 1 and 2, comprising two pipe fixing frames 1 which are arranged side by side, wherein a plurality of pipe brackets 2 are arranged at the bottom between the two pipe fixing frames 1, the pipe fixing frames 1 are used for fixing the two ends of the polyethylene pipe in the length direction and preventing the rotation of the polyethylene pipe, and the pipe brackets 2 form necessary supports for the bottom of the pipe.

The pipe fixing frame 1 is internally provided with a concentric center lead screw 3, the center lead screw 3 coincides with the axis position of a pipe to be processed, the front end of the center lead screw 3 is provided with a first guide wheel 4, the first guide wheel 4 can walk at the bottom of the inner wall of the pipe, the front side of the pipe fixing frame 1 is provided with a lead screw bracket 5, the lead screw bracket 5 is provided with a positioning jack 6 matched with the center lead screw 3, and when the center lead screw 3 moves forwards into the positioning jack 6, the movement is stopped to realize the self positioning.

The rear end of the center screw 3 is provided with a screw translation mechanism, the screw translation mechanism can drive the center screw 3 to horizontally move close to or far away from the screw support 5, in order to prevent the first guide wheel 4 from losing support in the height direction when moving out of the pipe, guide wheel supports 7 are arranged between the pipe fixing frame 1 and the screw support 5 and between the pipe fixing frame 1 and the screw translation mechanism, the bottoms of the guide wheel supports 7 and the inner wall of the pipe are flush, and further vertical fluctuation of the first guide wheel 4 in the moving process is avoided, and cutting precision of the inner wall of the pipe is guaranteed.

The center screw 3 is provided with a cutting platform 8 capable of moving along the axial direction in a matched mode, as shown in fig. 5 and 6, the bottom of the cutting platform 8 is provided with a telescopic platform supporting roller 9, and the platform supporting roller 9 can move inside the pipe. In order to ensure the stability of the movement of the cutting platform 8, a platform guide groove 10 is axially formed in the center screw 3, and a guide block 11 matched with the platform guide groove 10 is arranged on the cutting platform 8. The platform supporting roller 9 can be adjusted in vertical height, can be adjusted according to pipes with different diameters, ensures that the platform supporting roller 9 is contacted with the bottom of the inner wall of the pipe, does not influence the central screw 3 matched with the platform supporting roller 9 to be always positioned at the axial position of the pipe, and is suitable for cutting the inner wall of the pipe with different diameters.

The platform supporting roller 9 can move back and forth on the inner wall of the pipe, the design shape of the platform supporting roller 9 can be matched with the radian of the inner wall of the pipe, and the number of the platform supporting rollers 9 can be four or two.

An inner wall cutting mechanism is further installed in the cutting platform 8, the inner wall cutting mechanism comprises a milling cutter motor 12, a ball bearing 13 is installed between the cutting platform 8 and the center screw 3, a stator outer ring of the ball bearing 13 is fixed on the cutting platform 8, a rotor inner ring of the ball bearing 13 is sleeved on the periphery of the center screw 3, a rotating sleeve 14 is connected to the rotor inner ring of the ball bearing 13, and the milling cutter motor 12 can drive the rotating sleeve 14 to rotate through a transmission mechanism. The screw thread 15 which can be matched with the center screw 3 is arranged in the rotating sleeve 14, the milling cutter arm 16 is arranged on the periphery of the rotating sleeve 14, the milling cutter arm 16 is provided with the milling cutter 17 through the telescopic adjusting mechanism, when the milling cutter motor 12 is started, the rotating sleeve 14 rotates, the cutting platform 8 moves horizontally along the axial direction of the center screw 3 through the matching of the screw thread 15 and the center screw 3, and in the rotating process of the rotating sleeve 14, the milling cutter 17 also rotates synchronously to cut the inner wall of the pipe, namely, the milling cutter 17 moves in a spiral manner while the cutting platform 8 moves axially in the pipe, and the inner wall of the pipe is cut round by round to be smooth. When the screw thread 15 is disengaged from the center screw 3, the milling cutter motor 12 is started to only drive the milling cutter 17 to rotate, and the cutting platform 8 does not horizontally move relative to the center screw 3. The screw threads 15 can be two groups which are oppositely arranged, and the two groups can be matched with the center screw rod 3 in a two-way cohesion manner, so that necessary guiding and advancing effects are realized.

When the inner wall cutting device of the polyethylene plastic steel winding pipe is used for cutting the inner wall of the pipe, the pipe is firstly placed on the pipe support 2, and two ends of the pipe in the length direction are clamped and fixed through the pipe fixing frame 1, so that unnecessary rotation of the pipe in the machining process is avoided. The screw translation mechanism drives the center screw 3 to move forwards, the center screw 3 is led into the pipe through the first guide wheel 4, at the moment, the center screw 3 coincides with the axis of the pipe, after the center screw 3 moves into the positioning jack 6 in the screw bracket 5, the movement is stopped, and the center screw 3 is fixed on the screw bracket 5. The milling cutter motor 12 is started, at the moment, the screw thread 15 is matched with the center screw rod 3, the cutting platform 8 moves along the axial direction of the center screw rod 3, meanwhile, the milling cutter 17 also synchronously rotates to cut the inner wall of the pipe, and before cutting operation, the length of the extending distance of the milling cutter 17 can be adjusted through the telescopic adjusting mechanism, so that the milling cutter 17 is suitable for the pipe diameter and the cutting depth. The cutting platform 8 moves in the axial direction inside the pipe once to finish one-time cutting, and if the milling effect is not ideal, the cutting platform 8 can be moved to reset and then milling is repeated until the ideal milling effect is achieved. After milling, the screw thread 15 is separated from the central screw rod 3, the cutting platform 8 moves out of the pipe, the central screw rod 3 is driven by the screw rod translation mechanism to translate and withdraw from the pipe after the locking of the central screw rod 3 and the screw rod bracket 5 is released, the fixing of the pipe fixing frame 1 to two ends of the pipe in the length direction is released, and finally the machined pipe is taken out.

Further, as shown in fig. 4, the screw translation mechanism includes a translation control console 18, a translation motor 19 is installed in the translation control console 18, and a rubber roller 20 contacting with the central screw 3 is also installed in the translation control console 18, where the rubber roller 20 may be two rollers arranged up and down, the central screw 3 is clamped between the two rubber rollers 20, an output shaft of the translation motor 19 is connected with a rotating shaft of the rubber roller 20 through a power transmission belt 21, when the translation motor 19 is started, the rubber roller 20 can be driven to synchronously rotate, and under the action of friction force between the two rubber rollers, the central screw 3 is driven to horizontally move, and under the control of the translation motor 19, the rubber roller 20 can forward and backward rotate to realize the forward or backward movement of the central screw 3.

Because the length of the center screw 3 is longer, in order to ensure that the center screw 3 can play a necessary role in supporting when the center screw 3 is out of the pipe in a translation mode, the end part of the center screw 3, which extends out of the translation console 18, is provided with a second guide wheel 22, and the second guide wheel 22 can be in contact with the ground to jointly realize the supporting function of the center screw 3 with the first guide wheel 4.

The transmission mechanism may be other transmission structures such as a conventional sprocket chain mechanism or a gear-rack mechanism, etc., in order to realize accurate rotation driving of the milling cutter motor 12 to the rotary sleeve 14 and convenient maintenance of the whole device, as shown in fig. 7, the transmission mechanism is preferably arranged on the driven gear 23 on the rotary sleeve 14, the driving gear 24 is arranged on the output shaft of the milling cutter motor 12, a plurality of meshed transmission gears 39 are mounted on the cutting platform 8, the transmission gears 39 are respectively meshed with the driving gear 24 and the driven gear 23, and when the milling cutter motor 12 is started, the rotary sleeve 14 can be driven to rotate relatively accurately through the transmission of the driving gear 24, the transmission gears 39 and the driven gear 23, so that the milling cutter 17 rotates to mill the inner wall of the pipe.

When the cutting platform 8 is required to move in the pipe, the milling cutter 17 rotates to mill the inner wall, namely the screw thread 15 is matched with the center screw rod 3, the milling cutter motor 12 is started, the rotating sleeve 14 rotates, the cutting platform 8 horizontally moves under the guiding action of the center screw rod 3, and the milling cutter 17 also rotates. When the cutting platform 8 is required to be withdrawn from the pipe after milling, the milling cutter 17 is retracted for a certain distance to avoid damage to the inner wall of the pipe, the cooperation of the screw thread 15 and the center screw 3 is released, the milling cutter 17 is prevented from rotating along with the horizontal withdrawal of the cutting platform 8, namely, the screw thread 15 in the rotating sleeve 14 is separated from the center screw 3, only the cutting platform 8 horizontally moves, and the withdrawal movement speed of the cutting platform 8 is effectively accelerated.

To achieve the above purpose, the screw thread 15 is installed in the rotating sleeve 14 through a rotation locking mechanism, the rotation locking mechanism can achieve the matching or separating of the screw thread 15 and the central screw 3, as shown in fig. 7, the rotation locking mechanism comprises a square groove 25 formed in the rotating sleeve 14, the screw thread 15 is matched in the square groove 25 and cannot rotate, and the screw thread 15 can be close to or far away from the central screw 3 in the square groove 25. A locking rod 26 capable of rotating relatively is arranged in the screw thread 15, a handle 27 is arranged at one end of the locking rod 26 penetrating out of the rotating sleeve 14, a spring 28 is sleeved on the periphery of the locking rod 26 between the rotating sleeve 14 and the handle 27, and the spring 28 always has a trend of enabling the screw thread 15 to be far away from the center screw 3.

As shown in fig. 8, a long hole 29 is formed in the rotating sleeve 14, a long rod 30 matched with the long hole 29 is arranged on the locking rod 26, the long rod 30 can enter the rotating sleeve 14 through the long hole 29, and when the long rod 30 is positioned in the rotating sleeve 14, the screw thread 15 is meshed with the center screw 3. Rotating the locking lever 26 allows the bar 30 to be staggered with respect to the bar aperture 29 and allows the bar 30 to be locked within the rotating sleeve 14 under the force of the spring 28.

As shown in fig. 7, in the state that the screw thread 15 is matched with the central screw rod 3, at this time, the long bar 30 is located in the square groove 25 and is staggered with the long bar hole 29, under the action of the elastic force of the spring 28, the long bar 30 is propped against the top of the square groove 25, and the locking bar 26 cannot rotate under the action of no external force, that is, the long bar 30 cannot rotate to be matched with the long bar hole 29, so that the state that the screw thread 15 is matched with the central screw rod 3 is always maintained.

When the cutting platform 8 is required to withdraw from the pipe after milling, the screw thread 15 and the central screw 3 are separated from each other, a worker manually rotates the locking rod 26 to rotate the long rod 30 until the long rod 30 is matched with the long rod hole 29, then the long rod 30 moves out of the square groove 25 through the long rod hole 29 under the action of the elastic force of the spring 28, the screw thread 15 synchronously moves upwards to be disengaged from the central screw 3, and the milling cutter 17 cannot rotate when the cutting platform 8 moves horizontally.

In order to enable the screw thread 15 to be disengaged from the center screw rod 3, the cutting platform 8 can be moved out of the pipe more rapidly, a winch 37 is arranged between the screw rod translation mechanism and the pipe fixing frame 1, a recovery rope 38 connected with the cutting platform 8 is wound on a rotating shaft of the winch 37, the winch 37 is started to rapidly pull out the cutting platform 8 from the pipe, and the cutting platform 8 can be moved out smoothly along the axial direction of the center screw rod 3 under the action of the cooperation of the platform guide groove 10 and the guide block 11. The platform supporting roller 9 can be internally provided with a hub motor, and the screw thread 15 and the center screw 3 are separated from each other to drive the integral cutting platform 8 to horizontally move.

Further, in order to realize the clamping fixation to the pipe end, prevent that the tubular product from taking place to rotate in follow-up cutting process, as shown in fig. 3, tubular product mount 1 includes two semicircular clamp 31, all installs tubular product fastening card 32 through the telescopic link in each semicircular clamp 31, can adjust tubular product fastening card 32 to the inside extension length of semicircular clamp 31 through the flexible distance of adjusting the telescopic link, and then is applicable to the tubular product of various equidimension diameters, installs tubular product location on tubular product mount 1. The telescopic rod can be an existing electric push rod, and can achieve corresponding stretching and positioning functions when adjusting the telescopic length, so that the inner pipe is clamped and positioned in all directions. In order to reduce friction between the pipe support 2 and the pipe while supporting the pipe support 2, pipe supporting rollers 33 are also mounted on the pipe support 2.

Further, in order to cut the set thickness according to different types of pipes, the telescopic adjusting mechanism comprises a first screw rod 34 arranged on the milling cutter arm 16, a second screw rod 35 is arranged on the milling cutter 17, an adjusting screw sleeve 36 is arranged between the first screw rod 34 and the second screw rod 35 in a matched mode, threads of the first screw rod 34 and threads of the second screw rod 35 are opposite in rotation direction, the milling cutter 17 can be close to or far away from the milling cutter arm 16 by rotating the adjusting screw sleeve 36, and therefore the cutting radius of the milling cutter 17 is adjusted, and cutting requirements of different thicknesses inside pipe walls are met.

The screw thread 15 and the center screw 3 are driven in a matched manner, the platform supporting roller 9 is driven in a lifting manner, and the milling cutter 17 is driven in a telescopic adjusting mechanism through air pressure or oil pressure, so that precise distance driving is realized.

The technical scheme of the invention is not limited to the scope of the embodiments of the invention. The technical content that is not described in detail in the invention is known in the prior art.

Claims

1. An inner wall cutting device of polyethylene plastic steel winding pipe, its characterized in that: including two tubular product mounts (1) that arrange side by side, the bottom between two tubular product mounts (1) is equipped with a plurality of tubular product supports (2), install concentric setting central lead screw (3) in tubular product mount (1), first guide wheel (4) are installed to the front end of central lead screw (3), tubular product mount (1) front side is equipped with lead screw support (5), offer on lead screw support (5) with central lead screw (3) matched with location jack (6), install lead screw translation mechanism at the rear end of central lead screw (3), lead screw translation mechanism can drive central lead screw (3) horizontal migration and be close to or keep away from lead screw support (5), all install guide wheel support (7) between tubular product mount (1) and lead screw support (5) and between tubular product mount (1) and the lead screw translation mechanism, cutting platform (8) are installed along axial movement's cutting platform (8) are installed to the cooperation on central lead screw (3), telescopic platform supporting roller (9) are installed to the bottom of cutting platform (8), set up on central lead screw support (3) axial and are equipped with on cutting platform (8) guide block (10), guide motor (12) are installed in cutting platform (8), install ball bearing (13) between cutting platform (8) and central lead screw (3), the stator outer lane of ball bearing (13) is fixed on cutting platform (8), and the rotor inner race suit of ball bearing (13) is in the periphery of central lead screw (3), is connected with on the rotor inner race of ball bearing (13) and rotates cover (14), and milling cutter motor (12) can drive through drive mechanism and rotate cover (14) and rotate, install in rotating cover (14) can with central lead screw (3) matched with screw thread (15), be equipped with milling cutter arm (16) at the periphery of rotating cover (14), install milling cutter (17) through telescopic adjustment mechanism on milling cutter arm (16), can drive milling cutter (17) and rotate and cutting platform (8) along the axial horizontal migration of central lead screw (3) when milling cutter motor (12) start.

2. An inner wall cutting device for a polyethylene plastic steel wound pipe as claimed in claim 1, wherein: the screw translation mechanism comprises a translation control console (18), a translation motor (19) is arranged in the translation control console (18), a rubber roller (20) which is in contact with the central screw (3) is also arranged in the translation control console (18), an output shaft of the translation motor (19) is connected with a rotating shaft of the rubber roller (20) through a power transmission belt (21), and the rotation of the rubber roller (20) can drive the central screw (3) to horizontally move.

3. An inner wall cutting device for a polyethylene plastic steel wound pipe as claimed in claim 2, wherein: the end part of the center lead screw (3) extending out of the translation control console (18) is provided with a second guide wheel (22).

4. An inner wall cutting device for a polyethylene plastic steel wound pipe as claimed in claim 1, wherein: the transmission mechanism comprises a driven gear (23) arranged on the rotating sleeve (14), a driving gear (24) is arranged on an output shaft of the milling cutter motor (12), a plurality of meshed transmission gears (39) are arranged on the cutting platform (8), and the transmission gears (39) are respectively meshed with the driving gear (24) and the driven gear (23).

5. An inner wall cutting device for a polyethylene plastic steel wound pipe as claimed in claim 1, wherein: the screw thread (15) is installed in rotating sleeve (14) through rotating locking mechanism, rotating locking mechanism is including seting up square groove (25) in rotating sleeve (14), screw thread (15) can be close to or keep away from center lead screw (3) in square groove (25), install locking lever (26) that can rotate relatively in screw thread (15), one end that locking lever (26) worn out rotating sleeve (14) is equipped with handle (27), locking lever (26) periphery cover between rotating sleeve (14) and handle (27) is equipped with spring (28), spring (28) have all the time and let trend that screw thread (15) kept away from center lead screw (3), set up rectangular hole (29) on rotating sleeve (14), be equipped with on locking lever (26) with rectangular hole (29) matched with rectangular rod (30), rectangular rod (30) can be through rectangular hole (29) entering into rotating sleeve (14), rectangular rod (30) are located rotating sleeve (14) when rotating sleeve (15) one end meshing on center (3), rotating lever (26) can let rectangular rod (30) keep the effect of rectangular rod (30) and change rectangular rod (30) and let rectangular rod (30) to keep down in rotating sleeve (14) and lock spring (30).

6. The device for cutting the inner wall of a polyethylene plastic steel wound pipe according to claim 5, wherein: a winch (37) is arranged between the screw rod translation mechanism and the pipe fixing frame (1), and a recovery rope (38) connected with the cutting platform (8) is wound on a rotating shaft of the winch (37).

7. An inner wall cutting device for a polyethylene plastic steel wound pipe as claimed in claim 1, wherein: the pipe fixing frame (1) comprises two semicircular hoops (31), pipe fastening clamps (32) are arranged in each semicircular hoop (31) through telescopic rods, and pipe supporting rollers (33) are further arranged on the pipe support (2).

8. An inner wall cutting device for a polyethylene plastic steel wound pipe as claimed in claim 1, wherein: the telescopic adjusting mechanism comprises a first screw rod (34) arranged on a milling cutter arm (16), a second screw rod (35) is arranged on the milling cutter (17), an adjusting screw sleeve (36) is arranged between the first screw rod (34) and the second screw rod (35) in a matched mode, threads of the first screw rod (34) and threads of the second screw rod (35) are opposite in rotation direction, and the milling cutter (17) can be close to or far away from the milling cutter arm (16) by rotating the adjusting screw sleeve (36).