CN117047498A - Double-end beveling machine for large-diameter steel pipe - Google Patents

Abstract

The invention relates to the technical field of steel pipe machining, in particular to a double-end beveling machine for a large-diameter steel pipe, which comprises the following steps: the working platform is provided with a horizontal rail; the fixed base is arranged on the working platform and positioned at one end of the horizontal track; the movable base is arranged on the horizontal rail in a sliding manner; the gantry bracket is respectively arranged on the fixed base and the movable base, is used for clamping and fixing the steel pipe to be processed, and exposes two end parts of the steel pipe; and the groove assembly is respectively arranged on the fixed base and the movable base and is used for carrying out groove processing on the end part of the steel pipe. The double-end beveling machine realizes reliable clamping and rapid beveling of two ends of a steel pipe, and a plurality of cutters of different types are loaded on the cutter disc, so that the machining of a single V-shaped groove, a double V-shaped groove and a composite groove can be satisfied, the universality of equipment is improved, and the machining efficiency and the precision of groove machining are improved.

Description

Double-end beveling machine for large-diameter steel pipe

Technical Field

The invention relates to the technical field of steel pipe machining, in particular to a double-end beveling machine for a large-diameter steel pipe.

Background

As the diameter of the pipeline is larger and larger, the wall thickness range of the steel pipe is enlarged, the absolute values of the diameter deviation and the wall thickness deviation are larger and larger, and for the thin-wall steel pipe, the pipe end out-of-roundness has a great influence on the machining precision of the groove. In addition, the form of the end groove processing of the steel pipe is more and more, and frequent tool replacement is time-consuming and labor-consuming. The existing beveling machine has fewer beveling tools, the tools can only feed axially and cannot feed radially, one tool can only process a bevel at a specific angle, and when the angle of the bevel is changed, the tools can only be replaced, so that the time for beveling is prolonged.

Disclosure of Invention

Based on the problems, the invention aims to provide a double-end beveling machine for a large-diameter steel pipe, which improves the accuracy of beveling and the tool universality of bevels with different angles and compound bevels.

In order to achieve the above purpose, the invention adopts the following technical scheme:

a double-ended beveling machine for large diameter steel pipes, comprising:

the working platform is provided with a horizontal rail;

the fixed base is arranged on the working platform and positioned at one end of the horizontal track;

the movable base is arranged on the horizontal rail in a sliding manner;

the gantry bracket is respectively arranged on the fixed base and the movable base, is used for clamping and fixing the steel pipe to be processed, and exposes two end parts of the steel pipe;

the groove assembly is respectively arranged on the fixed base and the movable base and used for groove processing of the end part of the steel pipe, the groove assembly comprises a rotary cutter disc, an end face cutter, an inner bevel cutter, an outer bevel cutter and a travel cutter, the end face cutter, the inner bevel cutter, the outer bevel cutter and the travel cutter are used for processing the end face of the steel pipe, the inner bevel cutter is used for processing an inner V-shaped groove of the steel pipe, the outer bevel cutter is used for processing an outer V-shaped groove of the steel pipe with the wall thickness not exceeding 50mm, and the travel cutter is used for processing a composite groove and an outer V-shaped groove of the steel pipe with the wall thickness being greater than 50 mm.

Optionally, a plurality of radially arranged knife grooves are formed in the rotary cutter disc, dovetail grooves for installing a cutter base are formed in two sides of each knife groove, each knife groove comprises a through groove for installing a travel knife, a first half side groove for installing an outer bevel knife, a second half side groove for installing an inner bevel knife and a third half side groove for installing an end face knife, and the through groove, the second half side groove, the third half side groove and the two first half side grooves divide the disc surface of the rotary cutter disc into six equal parts.

Optionally, the groove assembly further comprises a sleeve for driving the rotary cutter disc to rotate, a driving shaft is arranged in the sleeve in a penetrating mode, a first bevel gear extending into the rotary cutter disc is arranged at the end portion of the driving shaft, a lead screw is arranged in the through groove, a second bevel gear matched with the first bevel gear is arranged on the lead screw, a nut is arranged on the lead screw, the driving shaft rotates to drive the lead screw to rotate, the nut is driven to move along the axial direction of the lead screw, and the base of the travel cutter is fixedly connected with the nut.

Optionally, the gantry bracket comprises a frame erected on the fixed base and the movable base, a plurality of V-shaped seats are annularly distributed on the frame, each V-shaped seat is driven by an independent hydraulic cylinder to feed towards the annular center, and an arc-shaped base plate contacted with the surface of the steel pipe is arranged on each V-shaped seat.

Optionally, the frame is square, and is provided with V type seat on the four sides of frame respectively, and the V type seat on higher authority cooperates with V type seat on lower and forms the clamping force on the vertical direction to the steel pipe, and the V type seat on left cooperates with V type seat on right and forms the clamping force on the horizontal direction to the steel pipe.

Optionally, the distance between the arc-shaped base plate of the upper V-shaped base and the arc-shaped base plate of the lower V-shaped base and the distance between the arc-shaped base plate of the left V-shaped base and the arc-shaped base plate of the right V-shaped base are measured through a magnetic grating ruler respectively, after the four arc-shaped base plates are in contact with the surface of the steel pipe, the clamping force in the corresponding direction is adjusted according to the measured distance value feedback, and the ratio of the difference value of the two distance values to the nominal diameter of the steel pipe is controlled within 1.5%.

Optionally, the lower V-shaped seats on the two gantry brackets are controlled to be equal in height through a magnetic grid ruler, so that the steel pipe is in a horizontal state after being clamped.

Optionally, the groove assembly further comprises a groove main body, the rotary cutter head is installed on the groove main body, sliding table mechanisms along the axial direction of the steel pipe are respectively arranged on the fixed base and the movable base, and the groove main body is driven by the sliding table mechanisms to feed along the axial direction of the steel pipe.

Optionally, racks are arranged on the horizontal track, a transmission gear matched with the racks is arranged on the movable base, and the transmission gear is driven to rotate by a speed reducer so as to drive the movable base to reciprocate relative to the fixed base.

Optionally, a plurality of lifting supports are arranged on the working platform and between the fixed base and the movable base, and supporting seats for supporting the steel pipes are arranged on the lifting supports.

In summary, compared with the prior art, the double-end beveling machine for the large-diameter steel pipe has the following advantages:

1) Two groove components are adopted to process two ends of the steel pipe at the same time, so that the processing efficiency is remarkably improved;

2) The distance between the two groove components can be adjusted at will and quickly, and the two groove components are suitable for steel pipes with different lengths;

3) The clamping force is respectively adjusted by a plurality of hydraulic cylinders in a gantry support mode, so that the out-of-roundness of the pipe end of the steel pipe can be calibrated;

4) The cutter head is provided with a plurality of cutter grooves, a plurality of cutters of different types can be arranged, a single V-shaped groove, a double V-shaped groove, a composite groove and the like can be processed, the cutters of different types are not interfered with each other, and the cutter changing time is saved;

5) The rotary motion of the cutter head and the radial feeding of the travel cutter are not interfered with each other, the travel cutter can realize axial feeding and radial feeding simultaneously, and the efficiency of processing large-wall-thickness steel pipe grooves and composite grooves is improved.

Drawings

Fig. 1 is a schematic structural view of a double-ended beveling machine for large-diameter steel pipes according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a gantry bracket in a double-end beveling machine for a large-diameter steel pipe, which is provided by the embodiment of the invention;

fig. 3 is a schematic structural view of a groove assembly in a double-end beveling machine for a large-diameter steel pipe according to an embodiment of the present invention;

fig. 4 is an end view schematically showing a cutterhead in a double-end beveling machine for a large-diameter steel pipe according to an embodiment of the present invention.

In the figure:

1. a working platform; 11. a horizontal rail;

2. a fixed base;

3. a movable base;

4. a gantry bracket; 41. a frame; 42. a V-shaped seat; 43. a hydraulic cylinder; 44. an arc-shaped backing plate;

5. a groove assembly; 51. rotating the cutterhead; 52. a sleeve; 53. a knife slot; 531. a through groove; 532. a first half-groove; 533. a second half-side groove; 534. is formed on the first half side of the first half side; 54. a dovetail groove; 55. a drive shaft; 56. a first bevel gear; 57. a screw rod; 58. a second bevel gear; 59. a nut;

6. a slipway mechanism;

7. lifting the bracket; 71. and a supporting seat.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar parts throughout, or parts having like or similar functions. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

In the description of the present invention, unless explicitly stated and limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, mechanically connected, electrically connected, indirectly connected through an intermediary, or may be in communication with each other between two elements or in an interaction relationship between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the description of the present invention, unless explicitly stated and limited otherwise, a first feature "above" or "below" a second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature not being in direct contact but being in contact by another feature therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature. The technical scheme of the invention is further described below by the specific embodiments with reference to the accompanying drawings.

Referring to fig. 1 to 4, the present preferred embodiment provides a double-ended beveling machine for large diameter steel pipes, which comprises a working platform 1, a fixed base 2, a movable base 3, a gantry bracket 4 and a beveling assembly 5.

Wherein, be provided with horizontal track 11 on the work platform 1, unable adjustment base 2 installs on work platform 1 and is located horizontal track 11's one end, and movable base 3 slides and sets up on horizontal track 11.

Specifically, racks are arranged on the horizontal track 11, the lengths of the racks are determined according to the longest and shortest lengths of the processed steel pipes, a transmission gear matched with the racks is arranged on the movable base 3, and the transmission gear is driven to rotate by a speed reducer so as to drive the movable base 3 to reciprocate relative to the fixed base 2, so that the steel pipes with different lengths can be adapted.

Wherein, the gantry bracket 4 is respectively arranged on the fixed base 2 and the movable base 3, is used for clamping and fixing the steel pipe to be processed, and exposes two ends of the steel pipe.

Specifically, referring to fig. 2 in detail, the gantry bracket 4 includes a frame 41 erected on the fixed base 2 and the movable base 3, a plurality of V-shaped seats 42 are annularly distributed on the frame 41, each V-shaped seat 42 is driven by a separate hydraulic cylinder 43 to feed toward an annular center, and an arc-shaped pad 44 contacting with the surface of the steel pipe is provided on the V-shaped seat 42.

The frame 41 in this embodiment is square, and V-shaped seats 42 are respectively provided on four sides of the frame 41, the upper V-shaped seat 42 and the lower V-shaped seat 42 cooperate to form a clamping force on the steel pipe in the vertical direction, the left V-shaped seat 42 and the right V-shaped seat 42 cooperate to form a clamping force on the steel pipe in the horizontal direction, and each hydraulic cylinder 43 is controlled by an independent electromagnetic valve and can act independently to adjust the clamping force in the vertical direction and the horizontal direction.

The gantry bracket 4 can clamp steel pipes with diameters below 1500mm, and clamps for steel pipes with different diameters do not need to be replaced. The arc-shaped backing plates 44 with the same or similar radian are adopted for the steel pipes with different diameters, so that the supporting surface of the arc-shaped backing plates 44 is better attached to the steel pipes during clamping, and the clamping device has the advantages of being stable in clamping and convenient to operate.

Further, the distance between the arc-shaped pad 44 of the upper V-shaped seat 42 and the arc-shaped pad 44 of the lower V-shaped seat 42, and the distance between the arc-shaped pad 44 of the left V-shaped seat 42 and the arc-shaped pad 44 of the right V-shaped seat 42 are measured by a magnetic grating ruler, which adopts a magneto-electric design, and the absolute position of the reading head is determined by the magnetic induction device through the change of the magnetic field. After the four arc-shaped backing plates 44 are in contact with the surface of the steel pipe, the clamping force in the corresponding direction is adjusted according to the measured distance value feedback, the ratio of the difference value of the two distance values to the nominal diameter of the steel pipe is controlled within 1.5%, and is generally not more than 2mm, otherwise, the out-of-roundness of the end part of the steel pipe is larger, the machining precision of a groove can be influenced, at the moment, the clamping force of the hydraulic cylinder 43 in the direction with larger spacing can be adjusted, the spacing in the direction is reduced, and the effect of correcting the out-of-round steel pipe is achieved.

In addition, the lower V-shaped seats 42 on the two gantry brackets 4 can be controlled to be equal in height through a magnetic grating ruler, so that the steel pipe is in a horizontal state after being clamped, and the machining precision is ensured.

The groove assemblies 5 are respectively arranged on the fixed base 2 and the movable base 3 and are used for carrying out groove processing on the end parts of the steel pipes.

Specifically, the groove assembly 5 comprises a rotary cutter disc 51, and an end face cutter, an inner bevel cutter, an outer bevel cutter and a travel cutter which are not mutually influenced are loaded on the rotary cutter disc 51, wherein the end face cutter is used for processing the end face of a steel pipe, and the end face is perpendicular to the axis of the steel pipe; the inner groove cutter is used for processing an inner V-shaped groove of the steel pipe; the outer groove cutter is used for processing an outer V-shaped groove of the steel pipe with the wall thickness not exceeding 50 mm; the travel knife is used for processing the composite groove and the outer V-shaped groove of the steel pipe with the wall thickness of more than 50 mm.

Referring to fig. 3 in detail, the groove assembly 5 further includes a sleeve 52 for driving the rotary cutter head 51 to rotate, the surface of the sleeve 52 is provided with a driven wheel, the rotary motion of the rotary cutter head 51 is realized by an independent motor, and the motor is connected with the driven wheel through a belt transmission, so that the sleeve 52 drives the rotary cutter head 51 to perform rotary motion.

In order to meet the requirements of groove machining of steel pipes with different wall thicknesses and diameters below 1500mm, the disc surface diameter of the rotary cutter disc 51 is 1600mm, and the motor is preferably a variable frequency motor. For large diameter steel pipes, a lower rotation speed is selected, and for small diameter steel pipes, a higher rotation speed is selected. When the diameter of the steel pipe is 500mm to 1500mm, the corresponding rotation speed of the rotary cutterhead 51 can be referred to in table 1 below.

TABLE 1

Specifically, a plurality of radially arranged cutter grooves 53 are formed on the rotary cutter disc 51, dovetail grooves 54 for mounting cutter bases are formed on two sides of each cutter groove 53, each cutter groove 53 comprises a through groove 531 for mounting a travel cutter, a first half groove 532 for mounting an outer bevel cutter, a second half groove 533 for mounting an inner bevel cutter and a third half groove 534 for mounting an end surface cutter, as shown in fig. 4, the through groove 531, the second half groove 533, the third half groove and the two first half grooves 532 equally divide the disc surface of the rotary cutter disc 51 in six, the two first half grooves 532 are located on the same straight line, and if the number of cutter grooves 53 is increased or decreased, the disc surface adaptability of the rotary cutter disc 51 is equally divided.

Further, the axis of each cutter is perpendicular to the disk surface of the rotary cutter head 51, the cutter base is inserted into the through groove 531 or the dovetail grooves 54 on both sides of each half groove, and is locked by a locking mechanism, and the radial position of the cutter on the rotary cutter head 51 can be adjusted according to the diameter of the steel pipe.

Specifically, the sleeve 52 is provided with a driving shaft 55 in a penetrating way, the rotation of the driving shaft 55 is not interfered with the rotation of the sleeve 52, a first bevel gear 56 extending into the rotary cutter disc 51 is arranged at the end part of the driving shaft 55, a lead screw 57 is arranged in a through groove 531, a second bevel gear 58 matched with the first bevel gear 56 is arranged on the lead screw 57, a nut 59 is arranged on the lead screw 57, the driving shaft 55 rotates to drive the lead screw 57 to rotate, the nut 59 is driven to move along the axial direction of the lead screw 57, and the base of the travel cutter is fixedly connected with the nut 59.

Specifically, the stroke knife is a shockproof long knife with the length of 100-200 mm, the knife rest frame of the stroke knife is higher than the knife rest frame of the outer bevel knife and the knife rest frame of the inner bevel knife, and the outer bevel knife and the inner bevel knife fixed on the cutter head can not prevent the stroke knife from acting when the compound bevel is machined. When the outer V-shaped groove and the inner V-shaped groove are machined, the stroke knife rest is driven by the lead screw 57 and the nut 59 to move to a position close to the center of the cutter disc along the through groove 531 and the dovetail grooves 54 on the two sides, so that the actions of the outer groove knife and the inner bevel knife are not hindered.

Further, the end face cutter adopts a fixed cutter holder, and can be folded after finishing the processing of the end face of the pipe end, so that the groove processing of the pipe end by other cutters is not hindered; the outer bevel blade, the inner bevel blade and the travel blade all adopt floating blade holders, and when the out-of-roundness of the pipe end affects the machining cutting amount, the cutter is prevented from being subjected to excessive cutting force. In addition, the end face cutter, the outer bevel edge cutter, the inner bevel edge cutter and the travel cutter are all provided with limit switches, and after each cutter reaches a set feeding amount, the corresponding limit switches act, so that the cutter stops processing and automatically withdraws.

In addition, the groove assembly 5 further comprises a groove main body, the rotary cutter disc 51 is arranged on the groove main body, sliding table mechanisms 6 along the axial direction of the steel pipe are respectively arranged on the fixed base 2 and the movable base 3, the groove main body is driven by the sliding table mechanisms 6 to feed along the axial direction of the steel pipe, and further the rotary cutter disc 51 and each cutter are fed along the axial direction of the steel pipe, so that groove processing is completed. Specifically, the axial feed speed of the rotary cutterhead 51 is continuously adjustable in the range of 0 to 20mm/min, which is determined mainly based on the wall thickness of the steel pipe, the speed selection being seen in table 2 below.

TABLE 2

Wall thickness (mm)

≤10

10～30

30～60

60～80

80～100

≥100

Feed speed (rpm)

2～5

5～8

8～11

11～15

15～18

18～20

In addition, the rotary cutter disc 51 can move along the radial direction of the steel pipe through a transverse hand wheel, and the center of the cutter disc is ensured to coincide with the center of the end face of the steel pipe through a coaxiality detector; and the verticality display device is arranged on the rotary cutterhead 51, so that the verticality of the rotary cutterhead 51 can be monitored at any time, and the verticality error of the end face of the steel pipe is ensured not to exceed 2 per mill of the diameter of the steel pipe.

Particularly, a plurality of lifting supports 7 are further arranged on the working platform 1 and located between the fixed base 2 and the movable base 3, and supporting seats 71 for supporting the steel pipes are arranged on the lifting supports 7, so that span bending of the steel pipes can be avoided. The lifting support 7 adopts a hydraulic lifting mode, the lifting support 7 can be lifted independently, two or more lifting supports 7 can be lifted synchronously through the cooperation of the magnetic grating ruler, and the structure of the support seat 71 can be similar to that of the V-shaped seat 42, and the description is omitted here.

Based on the structure, firstly, an arc-shaped backing plate 44 with a proper radian is fixed on a V-shaped seat 42 of a gantry bracket 4 according to the diameter of a steel pipe to be processed, the steel pipe with a groove at the end part to be processed is horizontally placed on a lifting bracket 7, and the lifting position of the lifting bracket 7 is adjusted through the cooperation of a magnetic grating ruler, so that the steel pipe is horizontal; the distance between the movable base 3 and the fixed base 2 is adjusted, so that two ends of the steel pipe extend into the gantry bracket 4 and extend for a set length, and each V-shaped seat 42 of the gantry bracket 4 clamps the steel pipe. Comparing the distance between the arc-shaped backing plates 44 of the upper and lower V-shaped seats 42 with the distance between the arc-shaped backing plates 44 of the left and right V-shaped seats 42, if the difference between the two is more than 2mm, or the ratio of the difference between the two and the nominal diameter of the steel pipe is more than 1.5%, the clamping force of the hydraulic cylinder 43 in the direction with larger spacing needs to be adjusted, so that the spacing in the direction is reduced, and the effect of rounding the out-of-round steel pipe is achieved.

Secondly, adjusting the rotary cutter disc 51 to be positioned at a position vertical to the steel pipe, and determining the rotary speed according to the diameter and the wall thickness of the steel pipe; machining the end surfaces of two pipe ends of the steel pipe by using an end surface cutter, and setting the required end surface machining amount according to the original perpendicularity of the end surfaces of the steel pipe and the end surface condition; after the set end face machining amount is reached, the end face cutter stops machining and automatically retreats, and then the end face cutter is folded to be parallel to the cutter disc.

Moreover, for the steel pipe with the wall thickness not exceeding 50mm, an outer bevel edge is used for processing an outer V-shaped groove, if an inner V-shaped groove is processed at the same time, the radial positions of the outer bevel edge and the inner bevel edge on the rotary cutter disc 51 can be adjusted at the same time, particularly, the manual disc-driven cutter disc is used for detecting the distances between the outer bevel edge and the inner bevel edge at different circumferential positions and the outer circle and the inner circle of the pipe end, the outer bevel edge and the inner bevel edge are fixed at proper positions on the cutter disc, the axial feeding quantity of the outer V-shaped groove and the inner V-shaped groove is set, and each end of the outer V-shaped groove and the inner V-shaped groove of the pipe end can be processed at the same time by the two outer bevel edge and the inner bevel edge.

If the composite bevel is to be machined, the stroke blade carrier is fixed to the rotary cutter disc 51 at a proper position, and the stroke blade carrier is a vibration-proof long blade having a length of 100mm to 200mm, because the stroke blade carrier is higher than the outer bevel blade carrier and the inner bevel blade carrier, the outer bevel blade and the inner bevel blade fixed to the cutter disc do not interfere with the machining of the composite bevel.

In summary, the double-end beveling machine for the large-diameter steel pipe has the following advantages: (1) the structure is simple, various grooves can be processed, and the groove processing precision is high because the levelness of the axis of the steel pipe and the verticality of the cutter disc can be adjusted and the pipe end can be rounded; (2) the outer bevel edge and the inner bevel edge can be simultaneously used for processing at the two ends of the steel pipe, so that the processing efficiency is high; (3) the single V-shaped groove, the double V-shaped groove and the composite groove can be processed, so that various processing requirements are met; (4) the travel knife can realize axial feeding and radial feeding simultaneously, and the efficiency of processing the steel pipe groove with large wall thickness and the compound groove is improved.

The above embodiments merely illustrate the basic principles and features of the present invention, and the present invention is not limited to the above embodiments, but can be variously changed and modified without departing from the spirit and scope of the present invention, which is within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (10)

1. A double-ended beveling machine for large diameter steel pipes, comprising:

the device comprises a working platform (1), wherein a horizontal rail (11) is arranged on the working platform (1);

the fixed base (2) is arranged on the working platform (1) and is positioned at one end of the horizontal track (11);

the movable base (3) is arranged on the horizontal rail (11) in a sliding manner;

the gantry bracket (4) is respectively arranged on the fixed base (2) and the movable base (3) and is used for clamping and fixing the steel pipe to be processed and exposing two ends of the steel pipe;

groove component (5), arrange respectively in unable adjustment base (2) with on movable base (3) for carry out the groove processing to the tip of steel pipe, groove component (5) are including rotatory blade disc (51), load on rotatory blade disc (51) and do not influence terminal surface sword, interior slope sword, outer slope sword and the stroke sword that use each other, the terminal surface sword is used for processing the terminal surface of steel pipe, interior slope sword is used for processing the interior V type groove of steel pipe, outer slope sword is used for processing the outer V type groove of steel pipe that the wall thickness is no more than 50mm, the stroke sword is used for processing compound groove and the outer V type groove of steel pipe that the wall thickness is greater than 50 mm.

2. The double-end beveling machine for large-diameter steel pipes according to claim 1, wherein a plurality of radially arranged cutter grooves (53) are formed in the rotary cutter head (51), dovetail grooves (54) for installing cutter bases are formed in two sides of each cutter groove (53), each cutter groove (53) comprises a through groove (531) for installing a travel cutter, a first half groove (532) for installing an outer bevel cutter, a second half groove (533) for installing an inner bevel cutter and a third half groove (534) for installing an end surface cutter, and the through groove (531), the second half groove (533), the third half groove and two first half grooves (532) divide the disc surface of the rotary cutter head (51) into six equal parts.

3. The double-end beveling machine for large-diameter steel pipes according to claim 2, wherein the beveling assembly (5) further comprises a sleeve (52) for driving the rotary cutter head (51) to rotate, a driving shaft (55) is arranged in the sleeve (52) in a penetrating manner, a first bevel gear (56) extending into the rotary cutter head (51) is arranged at the end part of the driving shaft (55), a lead screw (57) is arranged in the through groove (531), a second bevel gear (58) matched with the first bevel gear (56) is arranged on the lead screw (57), a nut (59) is assembled on the lead screw (57), the driving shaft (55) rotates to drive the lead screw (57) to rotate, the nut (59) is driven to move along the axial direction of the lead screw (57), and the base of the travel cutter is fixedly connected with the nut (59).

4. Double-end beveling machine for large-diameter steel pipes according to claim 1, characterized in that the gantry bracket (4) comprises a frame (41) erected on the fixed base (2) and the movable base (3), the frame (41) is provided with a plurality of V-shaped seats (42) distributed annularly, each V-shaped seat (42) is driven by a separate hydraulic cylinder (43) to feed towards the annular center, and the V-shaped seats (42) are provided with arc-shaped backing plates (44) which are in contact with the surface of the steel pipe.

5. The double-end beveling machine for large-diameter steel pipes according to claim 4, wherein the frame (41) is square, V-shaped seats (42) are respectively arranged on four sides of the frame (41), the upper V-shaped seat (42) and the lower V-shaped seat (42) cooperate to form a clamping force in the vertical direction on the steel pipe, and the left V-shaped seat (42) and the right V-shaped seat (42) cooperate to form a clamping force in the horizontal direction on the steel pipe.

6. The double-end beveling machine for large-diameter steel pipes according to claim 5, wherein the distance between the arc-shaped base plate (44) of the upper V-shaped base (42) and the arc-shaped base plate (44) of the lower V-shaped base (42) and the distance between the arc-shaped base plate (44) of the left V-shaped base (42) and the arc-shaped base plate (44) of the right V-shaped base (42) are respectively measured by a magnetic grid ruler, and after four arc-shaped base plates (44) are in contact with the surface of the steel pipe, the clamping force in the corresponding direction is adjusted according to the measured distance values in a feedback manner, and the ratio of the difference value of the two distance values to the nominal diameter of the steel pipe is controlled within 1.5%.

7. Double-end beveling machine for large-diameter steel pipes according to claim 5, characterized in that the lower V-shaped seats (42) on two gantry brackets (4) are controlled to be equal in height by a magnetic grid ruler, so that the steel pipes are in a horizontal state after being clamped.

8. The double-end beveling machine for large-diameter steel pipes according to claim 1, wherein the beveling assembly (5) further comprises a beveling main body, the rotary cutter disc (51) is installed on the beveling main body, sliding table mechanisms (6) along the axial direction of the steel pipe are respectively arranged on the fixed base (2) and the movable base (3), and the beveling main body is driven by the sliding table mechanisms (6) to feed along the axial direction of the steel pipe.

9. The double-end beveling machine for large-diameter steel pipes according to claim 1, wherein racks are arranged on the horizontal rail (11), a transmission gear matched with the racks is arranged on the movable base (3), and the transmission gear is driven to rotate by a speed reducer so as to drive the movable base (3) to reciprocate relative to the fixed base (2).

10. The double-end beveling machine for large-diameter steel pipes according to claim 1, wherein a plurality of lifting supports (7) are arranged on the working platform (1) and between the fixed base (2) and the movable base (3), and a supporting seat (71) for supporting the steel pipes is arranged on the lifting supports (7).