Cold cutting flying saw machine

Abstract

The invention relates to the technical field of cutting machine tools, and discloses a cold cutting flying saw machine which comprises a movable clamping block and a positive pressure rod, the positive pressure rod drives the movable clamping block to reciprocate to clamp and fix a to-be-cut body, and the positive pressure rod provides two-stage pressurization for the movable clamping block to eliminate internal residual stress of the to-be-cut body. The first-stage pressurization is the rated pressure, the second-stage pressurization is the step pressurization to the working pressure on the basis of the first-stage pressure, and an axial compression rod is hinged to the joint of the positive compression rod and the movable clamping block and used for eliminating the tensile stress generated by contraction of a notch of a body to be cut. And the loading time period of the axial pressure rod to the movable clamping block is synchronous with the second-stage pressurizing time period. The internal residual stress of the pipe is eliminated through staged stepped pressurization and a pre-clamping stress release mechanism, compared with the prior art, the stress release efficiency can be improved, after cutting is completed, tensile stress generated by contraction of a notch is eliminated, and burrs or local deformation of the notch is prevented.

Description

Technical Field

[0001] The invention relates to the technical field of cutting machine tools, in particular to a cold-cut flying saw machine. Background Art

[0002] Flying saw cutting of welded pipes can be divided into cold cutting and hot cutting. Traditional hot cutting relies on friction and high temperature cutting, while cold cutting uses specially designed saw blades to mill the pipes at low speeds and uses coolant to achieve cooling, thus avoiding material deformation or burr formation caused by high temperature.

[0003] The cold-cut flying saw machine achieves fixed-length cutting by synchronously moving the saw blade and the steel pipe clamp, and adopts cold milling technology to achieve burr-free cutting of pipes. It is used for high-precision cutting of steel pipes. Its core advantages lie in high precision, low noise, environmental protection and intelligent control.

[0004] Due to the internal residual stress generated in the cold rolling, cold drawing and other plastic deformation processes, the free end of the cut will have residual stress redistribution during the cutting process, which will cause the cut to shrink and produce cut burrs or local deformation, affecting the high-precision cutting requirements of the equipment. In addition, at the moment when the saw blade starts to cut the steel pipe, there is an impact load, and the steel pipe clamp will produce cut burrs due to unstable clamping due to vibration during the clamping process. Therefore, a cold cutting flying saw is proposed to solve the above technical problems. Summary of the invention

[0005] In view of the shortcomings of the existing cold cutting flying saws mentioned in the background technology, the present invention provides a cold cutting flying saw machine, which has the advantages of improving the efficiency of eliminating residual stress, preventing cutting burrs caused by axial residual stress, and absorbing high-frequency vibrations by hydraulic damping, thereby solving the technical problems raised in the above background technology.

[0006] The present invention provides the following technical solution: a cold cutting flying saw machine, comprising a movable clamping block and a positive pressure rod, wherein the positive pressure rod drives the movable clamping block to move back and forth to complete the clamping and fixing of the body to be cut, and the positive pressure rod provides two-stage pressurization to the movable clamping block to eliminate the internal residual stress of the body to be cut, the first stage pressurization is to maintain the rated pressure, and the second stage pressurization is to step-pressurize to the working pressure based on the pressure of the first stage.

[0007] Preferably, an axial pressure rod is hinged at the connection between the positive pressure rod and the movable clamping block. The directions of the axial pressure rod and the positive pressure rod when loading the movable clamping block are perpendicular to each other. The axial pressure rod is used to eliminate the tensile stress caused by the contraction of the incision of the body to be cut.

[0008] Preferably, the period in which the axial pressure rod loads the dynamic clamp is synchronized with the second stage pressurization period.

[0009] Preferably, a pressure-delay cylinder is fixedly installed on one side of the positive-pressure rod, a pressure-delay piston is slidably sleeved in the pressure-delay cylinder, a limit pressure ring is fixedly connected to the inner wall of the pressure-delay cylinder and close to the positive-pressure rod, the limit pressure ring is used to limit the movement of the pressure-delay piston to the terminal position of the positive-pressure rod, a pressure-delay spring and a pressure regulating plate are provided on one side of the pressure-delay piston, one end of the pressure-delay spring contacts the pressure-delay piston, and the other end of the pressure-delay spring contacts the pressure regulating plate, the inner cavity of the pressure-delay cylinder is connected to the inner cavity of the axial pressure rod through a hydraulic oil pipe, and the inner cavity of the pressure-delay cylinder on the other side of the pressure-delay piston is connected to the inner cavity of the positive-pressure rod.

[0010] Preferably, a pressure regulating bolt is movably sleeved on one side of the pressure regulating plate, the pressure regulating bolt extends out of the pressure-delay cylinder, and the pressure regulating bolt is threadedly connected to the cylinder wall of the pressure-delay cylinder. The position of the pressure regulating plate is adjusted by the pressure regulating bolt to adjust the initial compression amount of the pressure-delay spring.

[0011] Preferably, one end of the axial pressure rod is hinged to one end of the support block, and the hinge point between the axial pressure rod and the support block is sleeved by opening an avoidance groove on the axial pressure rod, and the length direction of the avoidance groove is the same as the axial direction of the axial pressure rod.

[0012] Preferably, the initial elastic force of the hysteresis spring is adjusted to the working pressure of the cutting clamp to be applied to the cutting of short fixed-length steel pipes.

[0013] The present invention has the following beneficial effects: 1. The present invention eliminates the residual stress inside the pipe by applying pressure in stages and adopts a pre-clamping stress release mechanism, which can improve the stress release efficiency compared with the prior art.

[0014] 2. The present invention installs an axial pressure rod on the movable clamping block, so that the body to be cut is axially prestressed before cutting, so that after the cutting is completed, the tensile stress caused by the shrinkage of the incision is eliminated to prevent burrs or local deformation of the incision.

[0015] 3. The present invention installs a delay pressure cylinder in the hydraulic inlet section of the positive pressure rod, connects the delay pressure cylinder with the axial pressure rod, and under the action of the delay pressure piston and the delay pressure spring, the loading of the axial prestress is stably completed in the second half of the clamping force loading, which can reduce the precise coordination requirements of the servo system and avoid inaccurate fixed-length dimensional accuracy caused by premature loading of the axial prestress in the feeding stage.

[0016] 4. The present invention produces a slight movable performance through the avoidance groove opened at the end of the axial pressure rod and the cooperation of the hysteresis piston and the hysteresis spring, so that the cold cutting saw blade contacts the body to be cut to generate impact load and vibration during the cutting process. The high-frequency vibration can be absorbed by this hydraulic damping structure, which helps to improve the cutting accuracy of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the structure of a traditional cold-cut flying saw; Figure 2 It is a front view of the cold-cut flying saw of the present invention; Figure 3 For the present invention Figure 2 A schematic diagram of the structure enlargement at point A; Figure 4 For the present invention Figure 2 The top view after sectioning at aa in FIG. Figure 5 For the present invention Figure 4 A schematic diagram of the structure at B in FIG. Figure 6 For the present invention Figure 4 Schematic diagram of the position state of the axle pressure rod after the center pressure rod is retracted; Figure 7 For the present invention Figure 6 A schematic diagram of the structure at position C in FIG. Figure 8 For the present invention Figure 5 A schematic diagram of the structure at D in FIG. Fig. 9 For the present invention Figure 7 Schematic diagram of the enlarged structure at E in FIG.

[0018] In the figure: 1. Machine tool frame; 2. Clamping base; 3. Cutting base; 4. Cold cutting saw blade; 5. Moving clamp block; 6. Fixed clamp block; 7. Guard plate; 8. Mounting block; 9. Power mechanism; 10. Positive pressure rod; 11. Body to be cut; 12. Connecting block; 13. Axial pressure rod; 14. Support block; 15. Delay pressure cylinder; 16. Delay pressure piston; 17. Limit pressure ring; 18. Delay pressure spring; 19. Pressure regulating plate; 20. Pressure regulating bolt; 21. Avoidance groove. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] In order to facilitate the clarification of the types of flying saws targeted by this application, a guide is provided before the specific implementation method is described. Figure 1 , which is the basic structure of the cutting part of the current cold-cut flying saw. The clamping base 2 and the cutting base 3 slide synchronously on the top of the machine tool frame 1, and are driven to move back and forth by a power device. The top of the clamping base 2 is respectively embedded with a moving clamping block 5 and a fixed clamping block 6. The moving clamping block 5 and the fixed clamping block 6 cooperate to form a steel pipe clamping surface with different cross-sectional shapes (round pipes or square pipes, etc., such as Figure 1The cross-sectional shape of the body 11 to be cut in the figure), the fixed clamping block 6 is fixed on the clamping base 2 and does not move, and the dynamic clamping block 5 can move left and right along the clamping base 2. The movement of the dynamic clamping block 5 depends on electric or hydraulic drive. A mounting block 8 is embedded in one side of the clamping base 2, and a power mechanism 9 is fixedly installed on the other side of the clamping base 2 by an inner hexagonal bolt. A positive pressure rod 10 is provided at the output end of the power mechanism 9. The positive pressure rod 10 extends into the mounting block 8 and is fixedly connected to one side of the dynamic clamping block 5. The power mechanism 9 is opened by an electric or hydraulic station to push out the positive pressure rod 10, thereby pushing the dynamic clamping block 5 to move closer to or away from the fixed clamping block 6. A guard plate 7 is provided at the top end of the clamping base 2 and above the mounting block 8. The guard plate 7 is used to limit the longitudinal displacement of the dynamic clamping block 5 and to prevent waste chips from entering the vicinity of the positive pressure rod 10 during the cutting process. The mounting block 8 is used to support the installation of the positive pressure rod 10 and bear the reaction force when clamping the steel pipe. The movable clamp block 5 to the positive pressure rod 10 are a group, and there are two groups in total, which are symmetrically arranged along the length direction of the workpiece to be cut with the cold cutting saw blade 4 as the symmetry plane, and the cutting seam of the body 11 to be cut is located between the two groups of clamps.

[0021] Its working process is as follows: place the body 11 to be cut between the moving clamp block 5 and the fixed clamp block 6, and at the end position of the fixed-length cutting, move the clamping base 2 and the cutting base 3 along the length direction of the body 11 to be cut to the starting position, start the power mechanism 9 and the positive pressure rod 10, so that the moving clamp block 5 cooperates with the fixed clamp block 6 to clamp the body 11 to be cut, and then start the driving mechanism to drive the clamping base 2 and the cutting base 3 to move along the length direction of the machine tool frame 1 to the fixed length direction. During this movement, the clamped and fixed body 11 to be cut also moves synchronously to complete the loading preparation for the next sawing. When the cutting base 3 moves to the end position of the fixed-length cutting, push down the cold cutting saw blade 4 for cutting. After the cutting is completed, release the power mechanism 9 and the positive pressure rod 10, and at the end position of the fixed-length cutting, move the clamping base 2 and the cutting base 3 along the length direction of the body 11 to be cut to the starting position, forming a cutting cycle.

[0022] The present invention discloses a cold-cut flying saw machine, please refer to Figure 2 , Figure 3 , Figure 4 and Figure 5One side of the moving clamp block 5 is fixedly connected with a connecting block 12, and the connecting block 12 and the moving clamp block 5 are fixedly installed by hexagon socket bolts. A positive pressure rod 10 and an axial pressure rod 13 are hinged on one side of the connecting block 12 at the same time. The output end of the positive pressure rod 10 is hinged to one side of the connecting block 12, and the output end of the axial pressure rod 13 is hinged to one side of the connecting block 12. The hinge points of the positive pressure rod 10, the connecting block 12, and the axial pressure rod 13 are coaxial, and the other end of the axial pressure rod 13 is hinged to one end of the support block 14, and the other end of the support block 14 is fixedly connected to the inner wall of the mounting block 8. The mounting block 8 is a rectangular block, and an installation groove is opened from the middle of the mounting block 8 for the installation space required for the structure of the present invention. A pressure-delay cylinder 15 is fixedly installed on one side of the positive pressure rod 10, and a pressure-delay piston 16 is slidably sleeved in the pressure-delay cylinder 15. A limit pressure ring 17 is fixedly connected to the inner wall of the pressure-delay cylinder 15 and close to the positive pressure rod 10. The limit pressure ring 17 is used to limit the movement of the pressure-delay piston 16 to the terminal position of the positive pressure rod 10 and to bear the axial force. A pressure-delay spring 18 and a pressure regulating plate 19 are provided on one side of the pressure-delay piston 16. One end of the pressure-delay spring 18 contacts the pressure-delay piston 16, and the other end of the pressure-delay spring 18 contacts the pressure regulating plate 19. A pressure regulating bolt 20 is movably sleeved on one side of the pressure regulating plate 19. The pressure regulating bolt 20 extends out of the outside of the pressure-delay cylinder 15, and the pressure regulating bolt 20 is threadedly connected to the wall of the cylinder 15. By adjusting the position of the pressure regulating plate 19 by the pressure regulating bolt 20, the initial compression amount of the pressure-delay spring 18 can be adjusted to achieve the pressure regulating function. The inner cavity of the pressure-delay cylinder 15 is communicated with the inner cavity of the axial pressure rod 13 through a hydraulic oil pipe, and the inner cavity of the pressure-delay cylinder 15 located on the other side of the pressure-delay piston 16 is communicated with the inner cavity of the positive pressure rod 10 .

[0023] See also Figure 6 , Figure 7 , Figure 8 and Fig. 9 The hinge point of the axial pressure rod 13 and the support block 14 is connected by opening an avoidance groove 21 on the axial pressure rod 13. The length direction of the avoidance groove 21 is the same as the axial direction of the axial pressure rod 13. The length of the avoidance groove 21 is adapted to the length requirement brought by the rotation angle of the axial pressure rod 13. This length requirement is specifically: the moving clamping distance of the dynamic clamping block 5 drives the axial pressure rod 13 to rotate around the support block 14 at a fixed point. Under the premise that the amount of hydraulic oil in the hysteresis cylinder 15 and the axial pressure rod 13 remains unchanged, in order to adapt to the linear movement of the output end of the axial pressure rod 13 with the connecting block 12, and the axial pressure rod 13 rotates around the support block 14 at the same time, the required length change of the axial pressure rod 13.

[0024] Thus, the method of use of the present invention is as follows: Figure 4 , Figure 5 and Figure 8When the liquid pressure is gradually introduced into the positive pressure rod 10, before the liquid pressure reaches the initial elastic force of the delay pressure spring 18, the liquid pressure in the positive pressure rod 10 applies positive pressure to the connecting block 12 through its output end, so that the movable clamping block 5 moves forward to the fixed clamping block 6, forming an extrusion clamping on the body to be cut 11, and completing the radial pressure on the body to be cut 11; continue to apply pressure to the positive pressure rod 10, when the liquid pressure reaches a balance with the initial elastic force of the delay pressure spring 18, at this time, the two sides of the delay pressure piston 16 are equivalent to being unpressurized, and thereafter, continue to apply pressure, that is, the delay pressure cylinder 15 will transmit pressure to the axial pressure rod 13, the support block 14 will be pressed against the top end of the avoidance groove 21, and the axial pressure rod 13 will apply axial pressure to the connecting block 12 along the axial direction of the body to be cut 11. That is, the static friction force generated by the positive pressure of the positive pressure rod 10 on the connecting block 12 generates an axial force in the forward direction of the body 11 to be cut under the horizontal action of the axial pressure rod 13 on the connecting block 12 (the other set of clamping parts generates a force in the opposite direction), thereby generating a relative extrusion stress for the cutting point of the body 11 to be cut.

[0025] The axial positive pressure of the axial pressure rod 13 can also be controlled by an independent hydraulic system, which requires that the positive pressure rod 10 pressurizes the dynamic clamp block 5 and then pressurizes it synchronously.

[0026] The purpose of the above-mentioned implementation technology is to provide radial positive pressure and axial positive pressure to the body 11 to be cut in turn, thereby applying prestress to the body 11 to be cut in sections, so that the residual stress in the body 11 to be cut can be released. After the cutting is completed, the deformation of the cutting pipe mouth can be effectively controlled to reduce the deformation caused by the stress change of the cutting mouth.

[0027] The specific implementation steps are as follows: S1, adjusting the initial elastic force Fn of the hysteresis spring 18 by the pressure adjusting bolt 20; S2, introduce hydraulic pressure Fn into the positive pressure rod 10 and maintain it; S3, following step S2, continue to pressurize the positive pressure rod 10, and the pressurization method adopts step-by-step pressurization to the working pressure; S4, advancing the cold cutting saw blade 4 to start cutting.

[0028] The present invention provides an implementation method in which: in step S2, Fn is 500N and maintained for 3s, and in step S3, the step pressure is 50N / ms. The stress release efficiency can reach 92% compared with the traditional direct pressing process.

[0029] Through the above-mentioned settings and operations, the hysteresis piston 16 and the axial pressure rod 13 have slight movable properties. In the initial stage of cutting, that is, when the cold cutting saw blade 4 contacts the cutting body 11 to be cut and generates an impact load, the vibration energy of the dynamic clamping block 5 caused by it is transmitted through the connecting block 12, and then can be decomposed and consumed in two axial directions by the positive pressure rod 10 and the axial pressure rod 13, thereby avoiding unstable cutting caused by vibration and ensuring high-precision requirements during cutting.

[0030] In order to make the adjustment of the initial elastic force more intuitive, a scale may be provided on the threaded rod of the pressure regulating bolt 20 , and the scale is the elastic force calculated according to the deformation amount of the corresponding hysteresis spring 18 .

[0031] The components in the pressure-delay cylinder 15 can be installed by adding a sealing cover at one end of the pressure-delay cylinder 15 and threadedly installing it, and then installing the pressure-delay piston 16, the pressure-delay spring 18, the pressure-regulating plate 19, and the pressure-regulating bolt 20 inward in sequence.

[0032] In order to improve the working efficiency of cutting, step S2 starts at the starting point of the fixed-length cutting and ends at the end point, and step S3 starts when the cold-cutting saw blade 4 starts to push down and cuts, and is completed before it contacts the body 11 to be cut. Therefore, it is more suitable for the fixed-length cutting of long steel pipes, while for the short fixed-length cutting, since the residual stress of each section of the steel pipe is small, the residual stress elimination may not be performed, so the operation method for the short fixed-length steel pipe is: the initial elastic force of the hysteresis spring 18 is adjusted to the working pressure of the cutting clamp.

Claims

1. A cold-cut flying saw machine, comprising a movable clamping block (5) and a positive pressure rod (10), characterized in that: The positive pressure rod (10) drives the movable clamping block (5) to move back and forth to complete the clamping and fixing of the body to be cut (11). The positive pressure rod (10) provides two-stage pressurization to the movable clamping block (5) to eliminate the internal residual stress of the body to be cut (11). The first stage of pressurization is to maintain the rated pressure, and the second stage of pressurization is to step-pressurize to the working pressure based on the pressure of the first stage.

2. A cold-cut flying saw machine according to claim 1, characterized in that: An axial pressure rod (13) is hingedly connected at the connection between the positive pressure rod (10) and the movable clamp block (5). The axial pressure rod (13) and the positive pressure rod (10) are perpendicular to each other when loading the movable clamp block (5). The axial pressure rod (13) is used to eliminate the tensile stress generated by the contraction of the incision of the body (11) to be cut.

3. A cold-cut flying saw machine according to claim 2, characterized in that: The period during which the axial pressure rod (13) loads the movable clamp (5) is synchronized with the second stage pressurization period.

4. A cold-cut flying saw machine according to claim 2, characterized in that: A pressure-delay cylinder (15) is fixedly mounted on one side of the positive pressure rod (10), a pressure-delay piston (16) is slidably sleeved in the pressure-delay cylinder (15), a limit pressure ring (17) is fixedly connected to the inner wall of the pressure-delay cylinder (15) and close to the positive pressure rod (10), the limit pressure ring (17) is used to limit the movement of the pressure-delay piston (16) toward the end position of the positive pressure rod (10), a pressure-delay spring (18) and a pressure regulating plate (19) are provided on one side of the pressure-delay piston (16), one end of the pressure-delay spring (18) contacts the pressure-delay piston (16), and the other end of the pressure-delay spring (18) contacts the pressure regulating plate (19), the inner cavity of the pressure-delay cylinder (15) is connected to the inner cavity of the axial pressure rod (13) through a hydraulic oil pipe, and the inner cavity of the pressure-delay cylinder (15) located on the other side of the pressure-delay piston (16) is connected to the inner cavity of the positive pressure rod (10).

5. A cold-cut flying saw machine according to claim 4, characterized in that: A pressure regulating bolt (20) is movably sleeved on one side of the pressure regulating plate (19), the pressure regulating bolt (20) extends out of the pressure-delay cylinder (15), and the pressure regulating bolt (20) is threadedly connected to the cylinder wall of the pressure-delay cylinder (15). The position of the pressure regulating plate (19) is adjusted by the pressure regulating bolt (20) to adjust the initial compression amount of the pressure-delay spring (18).

6. A cold-cut flying saw machine according to claim 4, characterized in that: One end of the axial pressure rod (13) is hinged to one end of the support block (14), and the hinge point between the axial pressure rod (13) and the support block (14) is sleeved by an avoidance groove (21) provided on the axial pressure rod (13), and the length direction of the avoidance groove (21) is the same as the axial direction of the axial pressure rod (13).

7. The cold-cut flying saw machine according to claim 5, characterized in that: The initial elastic force of the hysteresis spring (18) is adjusted to the working pressure of the cutting clamp to be applied to the cutting of short fixed-length steel pipes.

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