Mechanical self-adaptive band sawing machine with constant cutting force and method thereof

Abstract

The present application relates to the field of metal cutting machine tool and automation control, in particular to a mechanical self-adaptive band sawing machine with constant cutting force and a method thereof; comprising a feeding driving part, a sawing function part, a mechanical self-adaptive measuring part and an industrial control computer; the system combines a floating guide arm and a spiral compression spring to convert the cutting reaction force received by the ring saw blade into mechanical displacement; the core is to use the straight rack to drive the measuring gear and the photoelectric encoder to detect the displacement, and then accurately calculate the real cutting force; the present application discards the traditional electronic force sensor, uses mechanical displacement conversion to solve the problems of unstable signal and easy to be disturbed under harsh working conditions, effectively improves the anti-interference ability and cutting control precision of the system.

Description

Technical Field

[0001] This invention relates to the field of metal cutting machine tools and automation control, specifically to a mechanical adaptive band saw with constant cutting force and its method. Background Technology

[0002] Under current metal cutting conditions, band saws are commonly used for sawing pipes, H-beams, and other materials with variable cross-sections. During the cutting of these materials, the abrupt change in the cutting contact area when the saw blade crosses from a thick-walled region to a thin-walled or hollow region causes significant nonlinear fluctuations in the cutting reaction force. To complete such sawing operations, existing solutions generally employ a constant-speed feed control architecture, i.e., using a hydraulic system to drive the saw bow downwards at a fixed speed while maintaining a constant speed for the spindle motor. Although this solution has a certain cutting capability in the processing of solid bars with uniform cross-sections, its overall... Lacking the ability to sense and adapt to changes in cutting load, saw blades are prone to forward thrust and high-frequency vibration when facing cavities or thin-walled materials with sudden drops in resistance. In some cases, sudden changes in local stress can even lead to blade breakage. Some improvement solutions attempt to place strain gauge-based electronic force sensors directly in areas of high vibration and cutting fluid scouring to collect force data. However, this method is highly dependent on minute resistance changes, resulting in poor anti-interference capabilities, low signal stability, and an inability to quickly convert static force data into indicators that characterize the dynamic trend of resistance changes. This leads to high control response delays and makes it difficult to support high-frequency linkage adjustment of feed rate and spindle speed.

[0003] Therefore, how to stably obtain the real cutting force characteristics under high-frequency vibration and liquid washing conditions, and thereby achieve adaptive linkage and coordination between the feed pressing speed and the saw blade linear speed, has become an urgent technical problem to be solved. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a mechanically adaptive band saw with constant cutting force and a method thereof. Specifically, the technical solution of the present invention is as follows: A mechanically adaptive band saw with constant cutting force, comprising: The feed drive unit includes a base, a vertical column located on top of it, a feed hydraulic cylinder, and a feed slide that is slidably connected to the side of the vertical column. The feed hydraulic cylinder drives the feed slide to move up and down along the vertical column. The sawing function unit is connected to the side of the feed slide and driven by the feed drive unit. It includes a horizontal saw bow, a spindle servo motor, a drive wheel, a driven wheel, and a ring saw blade. The drive wheel and the driven wheel are located at the inner end of the horizontal saw bow. The ring saw blade is tensioned between the two wheels. The spindle servo motor drives the drive wheel to rotate. The mechanical adaptive measurement unit is located at the bottom of the horizontal saw bow and includes a fixed guide arm, a floating guide arm, a helical compression spring, and a displacement detection assembly. The fixed guide arm is fixed to the side of the horizontal saw bow near the drive wheel, and the floating guide arm slides along a linear guide rail to the side of the horizontal saw bow near the driven wheel. The helical compression spring abuts against the displacement detection assembly, which is connected between the horizontal saw bow and the floating guide arm. When the annular saw blade is subjected to cutting reaction force, it drives the floating guide arm to overcome the elastic force of the helical compression spring and slide upward along the linear guide rail. An industrial control computer is communicatively connected to the feed hydraulic cylinder, the spindle servo motor, and the displacement detection component, and is used to control the feed drive unit, the sawing function unit, and the mechanical adaptive measurement unit.

[0005] According to one embodiment of the present invention, the displacement detection assembly includes a rack fixed to the side of the floating guide arm, a measuring gear rotatably connected to the side wall of the horizontal saw bow, and a photoelectric encoder connected to the shaft of the measuring gear, wherein the measuring gear meshes with the rack.

[0006] According to one embodiment of the present invention, a spring guide post is machined on the top of the floating guide arm, and a helical compression spring is sleeved on the outside of the spring guide post. The top end of the helical compression spring abuts against the inner wall of the horizontal saw bow. The preload of the helical compression spring is set to a preset reference value greater than zero so that the floating guide arm is kept in the reference position when the ring saw blade is unloaded.

[0007] According to one embodiment of the present invention, both the fixed guide arm and the floating guide arm are machined with clamping grooves at their bottom ends, and a carbide guide block is fixed in the clamping groove. The annular saw blade passes through the gap between the carbide guide blocks.

[0008] According to one embodiment of the present invention, the shaft of the main spindle servo motor is directly connected to the drive wheel via a plum blossom coupling, the housing of the photoelectric encoder is fixed to the side wall of the horizontal saw bow via a flange, and the photoelectric encoder is connected to the shaft of the measuring gear via a cross-slider coupling.

[0009] According to one embodiment of the present invention, the extending direction of the linear guide is parallel to the feeding direction of the feed hydraulic cylinder.

[0010] According to one embodiment of the present invention, the side of the vertical column is machined with a dovetail guide rail, the feed slide is slidably connected to the dovetail guide rail, and the piston rod of the feed hydraulic cylinder has a preset stroke to meet the height requirements of the material to be cut.

[0011] A mechanical adaptive band saw control method with constant cutting force includes: S1. Control the spindle servo motor to drive the drive wheel to rotate, thereby driving the ring saw blade to rotate, and control the feed hydraulic cylinder to drive the horizontal saw bow to move downward. S2. Control the displacement detection component to record the zero coordinates when the floating guide arm is at the extreme position of the lower end of the linear guide rail; S3. When the ring saw blade contacts the material to be cut and generates a cutting reaction force that causes the floating guide arm to slide, the displacement detection component is controlled to continuously record measurement data within a set sampling period and calculate the actual upward displacement of the floating guide arm. S4. Calculate the moving speed and speed change trend of the floating guide arm based on the actual upward displacement of the adjacent sampling cycles; calculate the actual upward displacement of the current cycle, the stiffness coefficient of the pre-acquired helical compression spring, and the initial preload to calculate the actual cutting force borne by the ring saw blade. S5. Compare the actual cutting force with the preset target constant cutting force. When the actual cutting force is greater than the target constant cutting force, reduce the downward pressing speed of the feed hydraulic cylinder. When the actual cutting force is equal to or less than the target constant cutting force, if the moving speed of the floating guide arm is zero or positive but does not continue to increase, maintain the downward pressing speed of the feed hydraulic cylinder. S6. When the moving speed is positive and continues to increase, reduce the speed of the spindle servo motor; when the actual cutting force is equal to or less than the target constant cutting force and the moving speed is negative, increase the speed of the spindle servo motor and simultaneously increase the downward pressing speed of the feed hydraulic cylinder. S7. Repeat the steps from controlling the displacement detection component to record measurement data to maintaining the rotational speed of the spindle servo motor and the pressing speed of the feed hydraulic cylinder.

[0012] According to one embodiment of the present invention, the feed hydraulic cylinder is connected to a servo proportional valve; When the actual cutting force is greater than the target constant cutting force, the difference between the actual cutting force and the target constant cutting force is multiplied by a preset proportional coefficient to obtain the speed reduction amount. The current downward pressing speed of the feed hydraulic cylinder is subtracted from the speed reduction amount, which is then sent to the servo proportional valve as a new feed command to reduce the downward pressing speed.

[0013] According to one embodiment of the present invention, when the moving speed is positive and continuously increasing, the rate of change of the moving speed is extracted, the rate of change of the speed is multiplied by a preset speed compensation coefficient, and the compensation value is subtracted from the current speed of the spindle servo motor to reduce the linear speed of the ring saw blade. When the moving speed is negative, an acceleration command is issued to simultaneously increase the pressing speed of the feed hydraulic cylinder and the rotation speed of the spindle servo motor.

[0014] The present invention has the following beneficial effects: 1. This invention employs a mechanical adaptive measurement unit comprising a fixed guide arm, a floating guide arm, a helical compression spring, and a displacement detection assembly. It utilizes a rack and pinion drive measuring gear and a photoelectric encoder to record measurement data and calculate the actual lifting displacement. This structure overcomes the defect of unstable signal of traditional electronic force sensors under harsh working conditions, improves anti-interference capability, and can stably acquire the actual lifting displacement to accurately calculate the real cutting force. 2. This invention adjusts the downward pressing speed of the feed hydraulic cylinder by comparing the actual cutting force with the target constant cutting force, and synchronously adjusts the speed of the spindle servo motor by combining the moving speed and the speed change rate. This collaborative control method can effectively address the drastic fluctuations in resistance caused by sudden changes in the contact area of ​​the material to be cut, avoid the forward rushing and high-frequency vibration of the ring saw blade, and thus reduce the risk of blade breakage. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the device; Figure 2 This is a schematic diagram of the sawing function section of the device; Figure 3 This is a schematic diagram of the floating guide arm structure of the device; Figure 4 This is a schematic diagram of the displacement detection component of the device; Figure 5 This is a flowchart of the method of the present invention.

[0016] In the diagram: 1. Feed drive unit; 2. Base; 3. Vertical column; 4. Feed hydraulic cylinder; 5. Feed slide; 6. Sawing function unit; 7. Horizontal saw bow; 8. Spindle servo motor; 9. Drive wheel; 10. Driven wheel; 11. Ring saw blade; 12. Mechanical adaptive measurement unit; 13. Fixed guide arm; 14. Floating guide arm; 15. Helical compression spring; 16. Displacement detection assembly; 17. Linear guide rail; 18. Industrial control computer; 19. Spur rack; 20. Measuring gear; 21. Photoelectric encoder; 22. Spring guide column; 23. Clamping groove; 24. Carbide guide block; 25. Plum blossom coupling; 26. Flange; 27. Cross slider coupling; 28. Dovetail guide rail; 29. ​​Piston rod; 30. Servo proportional valve. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0018] Example 1: A mechanically adaptive band saw with constant cutting force, comprising: Combination Figure 1 The feed drive unit 1 includes a base 2, a vertical column 3 located on top of it, a feed hydraulic cylinder 4, and a feed slide 5 slidably connected to the side of the vertical column 3. The feed hydraulic cylinder 4 drives the feed slide 5 to rise and fall along the vertical column 3. Combination Figure 2 The sawing function unit 6 is connected to the side of the feed slide table 5 and is driven by the feed drive unit 1. It includes a horizontal saw bow 7, a spindle servo motor 8, a drive wheel 9, a driven wheel 10, and a ring saw blade 11. The drive wheel 9 and the driven wheel 10 are located at the inner end of the horizontal saw bow 7, and the ring saw blade 11 is tensioned between the two wheels. The spindle servo motor 8 drives the drive wheel 9 to rotate. Combination Figure 3 The mechanical adaptive measurement unit 12 is located at the bottom of the horizontal saw bow 7 and includes a fixed guide arm 13, a floating guide arm 14, a helical compression spring 15, and a displacement detection assembly 16. The fixed guide arm 13 is fixed to the side of the horizontal saw bow 7 near the drive wheel 9, and the floating guide arm 14 is slidably connected to the side of the horizontal saw bow 7 near the driven wheel 10 via a linear guide rail 17. The helical compression spring 15 abuts and engages. Figure 4 The displacement detection component 16 is connected between the horizontal saw bow 7 and the floating guide arm 14; when the ring saw blade 11 is subjected to cutting reaction force, it drives the floating guide arm 14 to overcome the elastic force of the helical compression spring 15 and slide upward along the linear guide rail 17. The industrial control computer 18 is connected to the feed hydraulic cylinder 4, the spindle servo motor 8 and the displacement detection component 16 respectively, and is used to control the feed drive unit 1, the sawing function unit 6 and the mechanical adaptive measurement unit 12. The base 2 is used to support the weight of the whole machine and absorb the sawing vibration. It can be made of cast iron or welded box structure. The vertical column 3 is fixed to the top of the base 2 and provides lifting and lowering guidance for the feed slide 5. The feed hydraulic cylinder 4 is set between the base 2 and the feed slide 5. It drives the feed slide 5 to move up and down along the vertical column 3 through the piston rod 29, thereby driving the horizontal saw bow 7 to feed as a whole. The horizontal saw bow 7 is installed on the side of the feed slide table 5. The drive wheel 9 and the driven wheel 10 are installed at both ends of the interior respectively. The ring saw blade 11 is tensioned between the two wheels. The spindle servo motor 8 is fixedly installed on the outer wall of the horizontal saw bow 7, which drives the drive wheel 9 to rotate to form the cutting line speed. The mechanical adaptive measurement unit 12 is arranged at the bottom of the horizontal saw bow 7, wherein the fixed guide arm 13 is located near the drive wheel 9, the floating guide arm 14 is located near the driven wheel 10, the ring saw blade 11 passes between the two guide arms and maintains the cutting posture under the constraint of the two guide arms; the bottom end of the floating guide arm 14 is machined with a guide member that slides in contact with the ring saw blade 11 to serve as a physical medium for transmitting the cutting reaction force. The floating guide arm 14 is slidably connected to the horizontal saw arm 7 via the linear guide rail 17. It can generate controlled displacement in the direction corresponding to the cutting reaction force. The helical compression spring 15 is set between the horizontal saw arm 7 and the floating guide arm 14 to provide reference elastic force and mechanical buffer. The displacement detection component 16 detects the displacement of the floating guide arm 14 in real time. The industrial control computer 18 receives the displacement signal and calculates the cutting force by combining it with the stiffness coefficient of the helical compression spring 15. Compared to the method of directly installing electronic force sensors in areas of high vibration and cutting fluid scouring, this structure first converts the cutting reaction force into mechanical displacement before detection, resulting in higher stability of the displacement signal. Furthermore, the measuring components are arranged on the side of the horizontal saw bow 7, which facilitates sealing and maintenance. A servo proportional valve 30 controlled by an industrial control computer 18 is connected in series in the hydraulic circuit of the feed drive unit 1. The industrial control computer 18 adjusts the downward pressing speed of the feed hydraulic cylinder 4 according to the calculated cutting force, and adjusts the speed of the spindle servo motor 8 according to the displacement change trend, so that the feed drive unit 1, the sawing function unit 6 and the mechanical adaptive measurement unit 12 form a mutually coordinated control relationship to adapt to the changes in cutting resistance of pipes, H-beams and other variable cross-section materials in thick-walled areas, thin-walled areas and cavity areas.

[0019] The displacement detection assembly 16 includes a rack 19 fixed to the side of the floating guide arm 14, a measuring gear 20 rotatably connected to the side wall of the horizontal saw bow 7, and a photoelectric encoder 21 connected to the shaft of the measuring gear 20, wherein the measuring gear 20 meshes with the rack 19. The displacement detection component 16 adopts a combination structure of rack and pinion and photoelectric encoder 21 to convert the linear displacement of the floating guide arm 14 into an angular displacement measurement signal; the straight rack 19 is fixed to the side of the floating guide arm 14 by screws, the length of the rack covers the entire effective stroke of the floating guide arm 14, and the tooth profile can adopt a standard involute tooth profile to reduce meshing error. The measuring gear 20 is mounted in the bearing seat on the side wall of the horizontal saw bow 7 via a bearing. The gear meshes with the rack 19. When the floating guide arm 14 slides up and down along the linear guide rail 17, the rack 19 drives the measuring gear 20 to rotate synchronously. The photoelectric encoder 21 is connected to the shaft of the measuring gear 20. The encoder outputs a pulse signal or an absolute angle signal. The industrial control computer 18 calculates the actual upward displacement of the floating guide arm 14 based on the correspondence between the pitch circle radius of the measuring gear 20 and the rotation angle. If the pitch circle radius of the measuring gear 20 is set as r, and the angular displacement obtained by the encoder is θ, then the displacement of the floating guide arm 14 can be converted by multiplying r by θ. This structure does not rely on the measurement of the small resistance change of the strain gauge, but uses geometric relationships to achieve displacement acquisition, and can maintain stable data output under conditions of iron filings, cutting fluid and continuous vibration. The side of the horizontal saw bow 7 is covered with a closed shell, which seals the measuring gear 20, the spur rack 19 and the photoelectric encoder 21 inside. The rack 19 is fixed to the side of the floating guide arm 14, so that the displacement acquisition path is consistent with the actual movement path of the floating guide arm 14, reducing intermediate conversion links and making it easier for the industrial control computer 18 to continue to calculate the cutting force, displacement change rate and speed change rate based on the displacement data. In actual equipment configuration, in order to balance measurement accuracy and structural compactness, the pitch circle radius of the measuring gear 20 is preferably set to 10mm to 30mm, and the photoelectric encoder 21 is preferably a multi-turn absolute encoder with a resolution of not less than 17 bits, so as to ensure sufficient resolution of the displacement change of the floating guide arm at the 14-micron level, and eliminate the step of re-zeroing after power failure and restart of conventional incremental encoders, further improving the data reliability of displacement detection component 16.

[0020] The top of the floating guide arm 14 is machined with a spring guide post 22, and a spiral compression spring 15 is sleeved on the outside of the spring guide post 22. The top of the spiral compression spring 15 abuts against the inner wall of the horizontal saw bow 7. The preload of the spiral compression spring 15 is set to a preset reference value greater than zero so that the floating guide arm 14 is kept in the reference position when the ring saw blade 11 is unloaded. A spring guide post 22 is provided at the top of the floating guide arm 14. The guide post can be a cylindrical boss, which is integrally processed with the floating guide arm 14 or installed separately and then fixed. A helical compression spring 15 is sleeved on the outside of the spring guide post 22. The guide post is used to limit the radial sway of the spring when it is compressed, and to prevent the spring from bending laterally during repeated compression, thereby ensuring the stability of the force direction of the floating guide arm 14. The top end of the spiral compression spring 15 abuts against the inner wall of the horizontal saw bow 7, and the bottom end abuts against the top surface of the floating guide arm 14. In the unloaded state, the spring is in a pre-compressed state, and the preload is set to 500N. This preload setting ensures that when the ring saw blade 11 is not in contact with the workpiece, the floating guide arm 14 is stably maintained at the reference position at the lower end of the linear guide rail 17, avoiding the floating guide arm 14 from drifting due to its own weight, band saw vibration, or slight friction. The lower end of the linear guide 17 is fixed with a limit stop to support the floating guide arm 14 in an unloaded state and provide a physical reference for the lower limit position. After the cutting starts, the floating guide arm 14 will only produce a measurable displacement when the cutting reaction force exceeds the threshold corresponding to the preload force. The industrial control computer 18 can distinguish between the unloaded approach stage and the actual cutting stage based on this. When calculating the cutting force, the industrial control computer 18 multiplies the displacement of the floating guide arm 14 by the stiffness coefficient of the helical compression spring 15, and then adds an initial preload of 500N to obtain the current cutting force; assuming the actual cutting force is... The stiffness coefficient of the helical compression spring 15 is The actual lift displacement is The initial preload is The calculation formula is: ; In actual conversions, since the linear guide 17 has an extremely low coefficient of friction and the surface of the carbide guide block 24 is lubricated, its frictional resistance is negligible relative to the main cutting reaction force, or it can be mitigated by applying an initial preload. Constant compensation is used to eliminate its influence; in terms of specific parameter settings, for common metal band saw cutting conditions, the stiffness coefficient of the helical compression spring 15 is... It can be set from 50N / mm to 150N / mm to ensure that the spring can provide smooth linear resistance without compression within the effective stroke of the floating guide arm 14, thus ensuring the linearity of the cutting force conversion relationship. By using the spring guide post 22 in conjunction with the preloaded spring, a clear force-displacement correspondence is established. Furthermore, the mechanical compliance of the spring body weakens the direct impact of high-frequency impacts on the displacement signal, making subsequent control easier to maintain stability.

[0021] Both the fixed guide arm 13 and the floating guide arm 14 have clamping grooves 23 machined at their bottom ends. Carbide guide blocks 24 are fixed in the clamping grooves 23, and the ring saw blade 11 passes through the gap between the carbide guide blocks 24. Both the fixed guide arm 13 and the floating guide arm 14 are provided with clamping grooves 23 at their bottom ends. The clamping grooves 23 are used to install carbide guide blocks 24. The carbide guide blocks 24 are fixed in the clamping grooves 23 by bolts or pressure plates. The material of the carbide block 24 can be wear-resistant carbide to withstand the long-term friction generated by the ring saw blade 11 during high-speed operation and load cutting. A guide gap is formed between the two sets of carbide guide blocks 24 for the ring saw blade 11 to pass through. The width of the gap is set according to the thickness of the ring saw blade 11 and the allowable lateral swing, so that the ring saw blade 11 can run smoothly and maintain the cutting direction. The guide block on one side of the fixed guide arm 13 provides a reference constraint, and the guide block on one side of the floating guide arm 14 moves together with the floating guide arm 14 under the action of the cutting reaction force. Therefore, the cutting reaction force can be directly transmitted to the floating guide arm 14 and the helical compression spring 15 through the guide block. Using carbide guide blocks 24 can reduce the wear rate of the guide surface, reduce saw blade sway caused by the expansion of the guide gap, and thus improve the consistency between displacement measurement and actual cutting reaction force. The clamping groove 23 is easy to disassemble and replace after the guide block is worn, and it is also easy to replace guide blocks of different thicknesses or different contact surfaces according to different saw blade specifications.

[0022] The shaft of the main spindle servo motor 8 is directly connected to the drive wheel 9 through the plum blossom coupling 25. The housing of the photoelectric encoder 21 is fixed to the side wall of the horizontal saw bow 7 through the flange 26. The photoelectric encoder 21 is connected to the shaft of the measuring gear 20 through the cross slider coupling 27. The output shaft of the main spindle servo motor 8 is directly connected to the drive wheel 9 shaft through the plum blossom coupling 25, eliminating the intermediate reduction or speed increase transmission stage, so that the speed change of the main spindle servo motor 8 can be directly transmitted to the drive wheel 9; the plum blossom coupling 25 has a certain compensation capability, which can absorb the small coaxiality deviation between the motor shaft and the drive wheel 9 shaft, and reduce the additional load caused by eccentricity; The housing of the photoelectric encoder 21 is fixed to the side wall of the horizontal saw bow 7 via flange 26. The flange 26 fixing method facilitates the stability of the encoder housing position and reduces the measurement deviation caused by relative vibration of the housing. The photoelectric encoder 21 is connected to the rotating shaft of the measuring gear 20 via a cross-slider coupling 27. The cross-slider coupling 27 allows for a certain axial deviation and a small installation error, so that the gear shaft system and the encoder shaft system can still stably transmit angular displacement when they are not completely coaxial. A plum blossom coupling 25 is used to connect the spindle servo motor 8 and the drive wheel 9, and a cross-slider coupling 27 is used to connect the encoder and the measuring gear 20. Error compensation can be performed on the power transmission chain and the measurement transmission chain respectively, so as to ensure that the sawing drive and displacement measurement have corresponding mechanical adaptability. This configuration reduces the additional pulsation caused by assembly errors and operating vibrations, so that the spindle speed control response and displacement detection response obtained by the industrial control computer 18 are closer to the actual mechanical state.

[0023] The extension direction of the linear guide 17 is parallel to the feed direction of the feed hydraulic cylinder 4; The linear guide rail 17 is arranged at the bottom of the horizontal saw bow 7 and is parallel to the feed direction of the feed hydraulic cylinder 4. The feed direction of the feed hydraulic cylinder 4 can be understood as the downward pressing direction of the horizontal saw bow 7 as a whole relative to the workpiece. The extension direction of the linear guide rail 17 is the movable direction of the floating guide arm 14. The two remain parallel, so that the main component of the cutting reaction force formed at the guide block is transmitted along the sliding direction of the floating guide arm 14, reducing the jamming and measurement distortion caused by the lateral component force; if there is an angle between the direction of the linear guide 17 and the feed direction, the floating guide arm 14 will generate both the component along the guide rail direction and the component perpendicular to the guide rail direction after being subjected to force, the latter will increase the guide rail friction and cause the conversion relationship between displacement and cutting force to deviate from linearity. After adopting a parallel arrangement, when the industrial control computer 18 calculates the cutting force based on the stiffness and displacement of the helical compression spring 15, the mechanical path is clearer, and the displacement of the floating guide arm 14 can be directly regarded as the response value of the cutting reaction force in the main direction. This structural relationship plays a fundamental role in constant cutting force control because when the measurement direction is consistent with the execution direction, the speed adjustment of the feed hydraulic cylinder 4 is more likely to correspond to the actual force changes.

[0024] The side of the vertical column 3 is machined with a dovetail guide rail 28, the feed slide 5 is slidably connected to the dovetail guide rail 28, and the piston rod 29 of the feed hydraulic cylinder 4 has a preset stroke to meet the height dimension requirements of the material to be cut. The side of the vertical column 3 is machined with dovetail guide rail 28. The feed slide 5 and the dovetail guide rail 28 cooperate to form a lifting guide pair. The dovetail guide rail 28 has an increased contact area and lateral load-bearing capacity, and is suitable for bearing the combined load of the horizontal saw bow 7, the drive wheel 9, the driven wheel 10 and the spindle servo motor 8 during the feeding process. When the feed slide 5 slides along the dovetail guide rail 28, the fitting clearance can be adjusted by the pressure plate or the wedge to control the guiding accuracy and motion damping; the piston rod 29 of the feed hydraulic cylinder 4 has a stroke of 600mm, which can cover the cutting height requirements of common pipes, steel sections and bars, and reserve enough distance for the return stroke of the saw bow. In actual operation, after the workpiece is placed in the working area of ​​the saw, the feed hydraulic cylinder 4 drives the feed slide 5 and the horizontal saw bow 7 to move downward as a whole until the ring saw blade 11 contacts the workpiece; after the cutting is completed, the feed slide 5 is driven to rise back to the standby position; the 600mm stroke, combined with the dovetail guide rail 28, enables the whole machine to maintain the stability of the saw bow posture within the entire stroke lifting range, providing a stable installation benchmark for the displacement measurement and constant force control of the floating guide arm 14.

[0025] Example 2: Combination Figure 5 A mechanical adaptive band saw control method with constant cutting force, comprising: S1. Control the spindle servo motor 8 to drive the drive wheel 9 to rotate, thereby driving the ring saw blade 11 to rotate, and control the feed hydraulic cylinder 4 to drive the horizontal saw bow 7 to move downward. S2. Control displacement detection component 16 records the zero coordinate of floating guide arm 14 when it is at the lower limit position of linear guide rail 17. S3. When the ring saw blade 11 contacts the material to be cut and generates a cutting reaction force that causes the floating guide arm 14 to slide, the displacement detection component 16 continuously records the measurement data within the set sampling period and calculates the actual upward displacement of the floating guide arm 14. S4. Calculate the moving speed and speed change trend of the floating guide arm 14 based on the actual upward displacement of the adjacent sampling cycles; calculate the actual cutting force borne by the ring saw blade 11 based on the actual upward displacement of the current cycle, the stiffness coefficient of the pre-acquired spiral compression spring 15, and the initial preload. S5. Compare the actual cutting force with the preset target constant cutting force. When the actual cutting force is greater than the target constant cutting force, reduce the downward pressing speed of the feed hydraulic cylinder 4. When the actual cutting force is equal to or less than the target constant cutting force, if the moving speed of the floating guide arm 14 is zero or positive but does not continue to increase, maintain the downward pressing speed of the feed hydraulic cylinder 4. S6. When the moving speed is positive and continues to increase, reduce the speed of the spindle servo motor 8; when the actual cutting force is equal to or less than the target constant cutting force and the moving speed is negative, increase the speed of the spindle servo motor 8 and simultaneously increase the pressing speed of the feed hydraulic cylinder 4. S7. Repeat the steps from recording measurement data from the control displacement detection component 16 to maintaining the speed of the spindle servo motor 8 and the pressing speed of the feed hydraulic cylinder 4; The control method is executed by the industrial control computer 18, which is electrically connected to the spindle servo motor 8 driver, the feed hydraulic cylinder 4 control unit and the displacement detection component 16 respectively. During the no-load approach stage, the industrial control computer 18 outputs a start command to drive the spindle servo motor 8 to rotate the drive wheel 9, and the ring saw blade 11 runs at the set initial linear speed. At the same time, it controls the feed hydraulic cylinder 4 to push the horizontal saw bow 7 to move downward. When unloaded, the floating guide arm 14 is located at the lower limit position of the linear guide rail 17, and the displacement detection component 16 collects this position as the zero coordinate. After the ring saw blade 11 contacts the material to be cut, the cutting reaction force is transmitted to the floating guide arm 14 through the carbide guide block 24. The floating guide arm 14 slides upward against the elastic force of the spiral compression spring 15. The displacement detection component 16 continuously collects and measures the angular displacement of the gear 20 and calculates the actual upward displacement of the floating guide arm 14. The industrial control computer 18 reads the stiffness coefficient k and the initial preload F0 of the spiral compression spring 15, and calculates the actual cutting force currently borne by the ring saw blade 11 according to the relationship that the actual cutting force is equal to k multiplied by the upward displacement plus F0. The industrial control computer 18 compares the actual cutting force with the target constant cutting force. When the actual cutting force is higher than the target value, it indicates that the cutting resistance has increased. The industrial control computer 18 outputs a deceleration control signal to reduce the downward speed of the feed hydraulic cylinder 4. When the actual cutting force is equal to or less than the target value, if the moving speed is detected... If the above logic holds, skip the following hold logic and proceed directly to the acceleration phase of S6; otherwise, maintain the current feed rate. The industrial control computer 18 simultaneously performs successive difference calculations on the displacement data obtained by continuous sampling, obtains the moving speed by dividing the displacement difference between adjacent sampling periods by the sampling time, and obtains the speed change rate by dividing the speed difference between adjacent sampling periods by the sampling time. When the moving speed is positive and continues to increase, it indicates that the cutting contact area is increasing, and the industrial control computer 18 reduces the speed of the spindle servo motor 8; when the moving speed is negative, it indicates that the cutting resistance is decreasing, and the industrial control computer 18 increases the speed of the spindle servo motor 8 and increases the pressing speed of the feed hydraulic cylinder 4; when the moving speed is zero or the moving speed is positive but does not continue to increase, the current spindle speed and feed speed are maintained. The above-mentioned steps of acquisition, conversion, comparison and adjustment are performed cyclically throughout the cutting process, so that the mechanical displacement measurement results directly participate in the speed adjustment, thereby adapting to the resistance changes of the variable cross-section material; the target constant cutting force is the target control quantity called by the industrial control computer 18 before the start of cutting. Its physical meaning is the nominal force level that the ring saw blade 11 is expected to maintain in the stable cutting stage. It serves as both a comparison benchmark for feed adjustment and a judgment input to distinguish between normal cutting and overload trends. The target value can be pre-entered by the operator according to the workpiece material type, cross-sectional specifications, saw blade pitch and initial spindle linear speed, or it can be automatically given by the industrial control computer 18 by calling the pre-stored parameter table of the corresponding material. It can be determined after fine-tuning by observing the displacement fluctuation range, sawing sound and cutting surface condition during the first trial cut. In fact, the calculation process of displacement, moving speed and speed change rate is carried out in the following order: the industrial control computer 18 reads the angular displacement data output by the photoelectric encoder 21 in each sampling cycle, and calculates the real-time displacement value of the floating guide arm 14 relative to the zero position coordinate based on the meshing relationship between the measuring gear 20 and the rack 19. The current displacement value is compared with the displacement value of the previous sampling period to obtain the displacement change in a single period. This change is then divided by the sampling period to obtain the moving speed. The moving speed in the current period is then compared with the moving speed in the previous period to obtain the speed change. This speed change is then divided by the sampling period to obtain the result, which is used to characterize the speed change rate. Specifically, let the sampling period be... ,in, For a positive integer greater than 1, the first... The actual upward displacement measured in each sampling period is , No. The actual upward displacement measured in each sampling period is Then the first The speed of movement per sampling period The calculation formula is: ; Combined with the The speed of movement per sampling period and sampling period Let the first The moving speed of each sampling period is The corresponding rate of change of velocity The calculation formula is: ; Through the above-mentioned explicit successive difference calculation, the industrial control computer 18 can transform static displacement data into dynamic indicators that characterize the rate of change of cutting resistance; send the displacement value into the force calculation stage, and send the speed and speed change rate into the spindle speed judgment stage and trend judgment stage, respectively. The input sources for the above processing flow are the angular displacement signal of the photoelectric encoder 21, the zero coordinate, the radius parameter of the measuring gear 20, and the internal sampling clock of the industrial control computer 18. The output results are real-time displacement, real-time speed, speed change trend, and actual cutting force, where the actual cutting force is used for the adjustment of the feed hydraulic cylinder 4, and the speed and speed change trend are used for the adjustment of the spindle servo motor 8. A positive and continuously increasing moving speed means that the floating guide arm 14 maintains an upward movement in multiple consecutive sampling periods, and the moving speed obtained in the later sampling period is greater than the moving speed obtained in the previous sampling period; in one embodiment, the condition of continuously increasing speed can be used as the condition that the moving speed meets the relationship in three consecutive sampling periods. A positive but not continuously increasing moving speed means that the current moving speed is greater than zero, but the continuous sampling results do not meet the aforementioned judgment condition of continuous increase; a moving speed of zero includes the speed calculation result being equal to zero and the near-zero state within the system's allowable error band, thereby avoiding frequent misjudgments caused by encoder quantization errors or sawing vibrations. The industrial control computer 18 preferably first performs a comparison between the actual cutting force and the target constant cutting force to determine whether the pressing speed of the feed hydraulic cylinder 4 needs to be corrected in this cycle, and then performs a judgment on the moving speed and the rate of change of speed to determine whether the speed of the spindle servo motor 8 needs to be corrected. When a deceleration command has been issued in the previous cycle and the movement speed is detected to turn negative in the next cycle, the industrial control computer 18 can release the deceleration holding state of the previous cycle and enter the acceleration judgment, so that the feed adjustment and spindle adjustment can maintain the same data flow logic under the same sampling reference. The above control method can be logically divided into three continuous processing parts: a measurement conversion unit, a force control judgment unit, and a trend compensation unit. The measurement conversion unit receives the encoder angular displacement signal and outputs the real-time displacement, moving speed, and speed change rate. The force control judgment unit receives the real-time displacement and calculates the actual cutting force, compares the actual cutting force with the target constant cutting force, and outputs the feed hold or feed deceleration result; the trend compensation unit receives the moving speed and the rate of change of speed, judges the increasing or decreasing trend of the cutting resistance, and outputs the spindle deceleration, spindle acceleration, or state hold result. The three processing sections use the output of the previous stage as the input of the next stage. Overall, they represent the causal relationship between the cutting reaction force transmitted from the saw blade to the floating guide arm 14 and converted into mechanical displacement, the displacement change reflecting the trend of material cross-section change, and finally driving the feed speed and spindle speed linkage correction. When the actual cutting force is greater than the target constant cutting force and the moving speed is positive and continues to increase, it indicates that not only has the actual force exceeded the target value, but the resistance is also continuing to increase. The industrial control computer 18 simultaneously executes feed deceleration and spindle deceleration during this sampling period. When the actual cutting force is equal to or less than the target constant cutting force and the moving speed is negative, it indicates that the current force has not exceeded the control target and the resistance is decreasing. The industrial control computer 18 can execute spindle speed increase and allow the feed to speed up. When the actual cutting force is equal to or less than the target constant cutting force and the moving speed is zero or positive but not continuously increasing, it is handled as a holding state. By using the above priority order and state combination relationship, it is possible to avoid the conflict of understanding between maintaining the feed rate and increasing the feed rate in the same sampling judgment, and to make the triggering conditions of each control action clearer. In the specific programming implementation, the sampling period of the industrial control computer 18 can be set to 10ms to 50ms, and the data collected by the displacement detection component 16 is transmitted in real time to the circular queue in the memory of the industrial control computer 18 through the industrial bus. To verify the adaptability of this method to materials with variable cross-sections, we take the theoretical deduction and actual test of cutting H-beams as an example: when the saw blade enters the thin-walled web region from the thick-walled flange, the sudden change in contact area leads to a nonlinear decrease in cutting force. Traditional constant-speed saws are prone to saw blade forward movement and high-frequency vibration because they cannot respond in time. In this embodiment, the industrial control computer 18 detects the negative change in the moving speed within 20ms and immediately increases the spindle speed and feed rate synchronously. This linkage response mechanism not only improves the cutting continuity in the cavity and thin-walled areas, but also avoids the risk of strip breakage caused by stress change. It verifies that the combination of algorithm logic and mechanical adaptive measurement can adapt to the cutting requirements of materials with variable cross-sections.

[0026] The feed hydraulic cylinder 4 is connected to a servo proportional valve 30; wherein, when the actual cutting force is greater than the target constant cutting force, the difference between the actual cutting force and the target constant cutting force is multiplied by a preset proportional coefficient to obtain the speed reduction amount; The current pressing speed of the feed hydraulic cylinder 4 is subtracted from the speed reduction amount, and a new feed command is sent to the servo proportional valve 30 to reduce the pressing speed. The oil flow rate of the feed hydraulic cylinder 4 is regulated by the servo proportional valve 30. The industrial control computer 18 outputs analog signals, current signals or bus control signals to the servo proportional valve 30 to change the extension and retraction speed of the hydraulic cylinder piston rod 29. The industrial control computer 18 calculates the difference between the actual cutting force and the target constant cutting force in each sampling period and records the difference as the force deviation. If the force deviation is greater than zero, the industrial control computer 18 will multiply the force deviation by a preset proportional coefficient to obtain the speed reduction. The unit of the proportional coefficient is set according to the control program as a conversion parameter between speed and force, and its value can be calibrated according to the hydraulic system flow characteristics, saw blade specifications and material type. The industrial control computer 18 subtracts the speed reduction from the current feed speed to obtain a new feed speed command, and sends the command to the servo proportional valve 30, causing the servo proportional valve 30 to reduce the opening of the corresponding valve port, thereby reducing the pressing speed of the feed hydraulic cylinder 4; if the force deviation continues to increase, the speed reduction will increase accordingly; if the force deviation decreases to near zero, the new feed speed will approach the current speed. This control method, which reduces the feed speed proportionally to the force deviation, has a clear calculation path and can directly use the cutting force obtained by converting the displacement of the floating guide arm 14 for hydraulic feed adjustment, avoiding the increase of saw blade force in thick-walled areas due to the constant pressing speed. Since the servo proportional valve 30 directly controls the hydraulic flow, this method can achieve real-time feed correction without changing the mechanical structure of the hydraulic cylinder. Force deviation indicates the degree to which the current actual cutting force exceeds the target constant cutting force. It is a direct judgment quantity for whether the feed hydraulic cylinder 4 needs to decelerate and the magnitude of the deceleration. Its input source is the actual cutting force and the target constant cutting force obtained in the previous embodiment. The industrial control computer 18 first compares these two quantities with the same dimension. Only when the actual cutting force is greater than the target constant cutting force will a positive force deviation be generated. When the actual cutting force is equal to or less than the target constant cutting force, the force deviation is treated as zero and will not be further amplified into a speed reduction amount. The method for determining the preset proportional coefficient is as follows: First, during the equipment debugging stage, select a typical workpiece material and a commonly used saw blade specification, and start trial cutting at the first preset feed speed; then gradually increase the feed speed and record the speed correction range required for the system to recover to stable cutting when the force deviation increases; select a coefficient value that can make the feed response free of overshoot and the saw blade force fluctuation lower than the safety preset threshold and write it into the parameter table of the industrial control computer. When cutting different materials in the future, different proportional coefficients can be called according to the material hardness grade or cross-sectional thickness grade. The logical function of the proportional coefficient is not to directly give the final flow rate, but to convert the force deviation into the amount of feed rate to be reduced, so that the industrial control computer 18 can send executable speed correction commands to the servo proportional valve 30 through a unified data interface. The process for generating a new feed command is as follows: first, read the current feed speed; then, determine whether the force deviation is greater than zero; if so, obtain the speed reduction amount based on the proportional coefficient; subtract the speed reduction amount from the current feed speed to obtain the new feed speed; convert the new feed speed into a valve opening command or control current command corresponding to the control mode of the servo proportional valve 30 and send it out. To avoid a sudden drop in feed command due to instantaneous impact, the industrial control computer 18 can set a minimum allowable value for the new feed speed. When the calculated result is lower than the minimum allowable value, the output is based on the minimum allowable value to ensure that the hydraulic cylinder remains under controlled pressure rather than completely losing feed. The final output of the above process is the control command of the servo proportional valve 30, which directly acts on the hydraulic feed circuit. The proportional adjustment relationship logically includes three sequential steps: force deviation acquisition, speed correction calculation, and valve port command output. The force deviation acquisition step receives the actual cutting force and the target constant cutting force as inputs and outputs whether the deviation is out of tolerance and the magnitude of the deviation. The speed correction calculation stage receives the out-of-tolerance amplitude and the preset proportional coefficient and outputs the speed decrease; the valve port command output stage receives the current feed speed and the speed decrease and outputs a new servo proportional valve 30 control command. The physical relationship represented by this logic structure is as follows: the greater the cutting force, the higher the actual resistance in the contact area between the saw blade and the workpiece, therefore the hydraulic cylinder should reduce the downward displacement per unit time; the more obvious the cutting force deviation, the more significant the increase in resistance, therefore the corresponding feed deceleration should also be greater. Since this implementation method directly corrects the speed based on the deviation amplitude, rather than directly correcting the pressure or flow target, it is easy to directly map the mechanically measured force changes into hydraulic feed actions, reducing intermediate data conversion steps. When the current cycle has entered the spindle deceleration state based on the trend, the feed deceleration in this embodiment is still triggered by the force deviation result. The two correspond to two different judgment dimensions: the current force magnitude and the force change trend. The former solves the problem of whether the constant force target is exceeded, and the latter solves the problem of whether the resistance is still increasing, thereby avoiding the confusion of the two types of control quantities into the same meaning. To further clarify the programming implementation logic and disclose the specific algorithm execution process, a quantitative simulation example is provided here: Assume the current feed rate command is 25 mm / min, the target constant cutting force is set to 1000 N, and the preset proportional coefficient is calibrated to 0.01 (mm / min) / N; when the industrial control computer 18 detects that the actual cutting force reaches 1200 N, the calculated force deviation is 200 N; The industrial control computer 18 multiplies the force deviation of 200N by the proportional coefficient of 0.01 to obtain a speed reduction of 2mm / min; the industrial control computer 18 subtracts the reduction of 2 from the current feed speed of 25 to obtain a new feed speed of 23mm / min, and converts it into the corresponding analog voltage or digital control word and sends it to the servo proportional valve 30. The above quantitative examples illustrate the calculation process by which the industrial control computer 18 performs quantitative adjustment of the servo proportional valve 30 based on force deviation.

[0027] When the moving speed is positive and continues to increase, the speed change rate of the moving speed is extracted, the speed change rate is multiplied by the preset speed compensation coefficient, and the compensation value is subtracted from the current speed of the spindle servo motor 8 to reduce the linear speed of the ring saw blade 11. When the movement speed is negative, an acceleration command is issued to simultaneously increase the pressing speed of the feed hydraulic cylinder 4 and the rotation speed of the spindle servo motor 8. The industrial control computer 18 performs continuous successive difference calculations on the displacement sequence of the floating guide arm 14 to obtain the moving speed and its changing trend. A positive moving speed indicates that the floating guide arm 14 continues to move upward, indicating that the cutting reaction force is still increasing. If the moving speed continues to increase in multiple consecutive sampling periods, it indicates that the cutting contact area has a further expansion trend. At this time, the industrial control computer 18 extracts the rate of change of the moving speed and multiplies the rate of change of the speed by a preset speed compensation coefficient to obtain the speed compensation value. Then, the current speed of the spindle servo motor 8 is subtracted from the compensation value to form a new speed command, thereby reducing the linear speed of the ring saw blade 11. After reducing the linear speed, although the single tooth cutting thickness may increase slightly under constant feed, it can significantly reduce the high-frequency impact kinetic energy and frictional heat accumulation rate when the saw teeth cut into the material, thereby suppressing the trend of overall resistance deterioration caused by thermal stress and high-frequency impact in the cutting zone. When the moving speed is negative, it indicates that the floating guide arm 14 has fallen back, the cutting reaction force has decreased, and the ring saw blade 11 may be moving from the thick-walled area to the thin-walled area or the cavity area. Based on this, the industrial control computer 18 issues an acceleration command, which increases the downward speed of the feed hydraulic cylinder 4 on the one hand, and increases the speed of the spindle servo motor 8 on the other hand, so that the cutting process maintains a high material removal rate during the resistance reduction stage. This method uses both the first-order and second-order displacement changes to correct the spindle speed. It not only adjusts the feed according to the current force state, but also pre-corrects the linear velocity according to the resistance change trend, so that the spindle speed adjustment and hydraulic feed adjustment are coordinated on the same data basis. In this embodiment, the rate of change of speed represents how fast the moving speed changes with time, and its physical meaning is the strength of the trend of increasing or decreasing cutting resistance. This quantity is not collected independently, but is obtained by the industrial control computer 18 through step-by-step processing of displacement data obtained from continuous sampling: first, the moving speed is calculated from the displacement sequence, then the speed change rate is obtained from the change of moving speed in adjacent cycles, and the speed change rate is sent to the speed compensation calculation stage. Therefore, the input sources for the rate of change of speed are the displacement data output by the displacement detection component 16 and the internal sampling time reference of the industrial control computer 18, and the output is a trend quantity used to correct the spindle speed. The logical function of the speed compensation coefficient is to convert the trend of resistance change into the range of spindle speed adjustment. Its determination method can be completed during the equipment debugging stage: first, select commonly used materials for trial cutting, record the saw blade force fluctuation, kerf stability and the effect of spindle speed correction under different speed change rates; then select the coefficient value that can make the speed adjustment response time within the preset period and not cause abnormal vibration of the saw blade and store it in the parameter table of the industrial control computer. For hard materials, thick-walled materials, and irregularly shaped materials with significant cavity variations, the industrial control computer 18 can call up different speed compensation coefficients; the spindle speed correction process can be executed in the following order: read the current cycle movement speed, and combine it with the movement speed of the previous two cycles to determine whether it meets the condition of being positive and continuously increasing; If satisfied, the speed change rate for that stage is extracted; the speed compensation value is obtained based on the speed compensation coefficient; the compensation value is then subtracted from the current speed of the spindle servo motor 8 to form a new spindle speed command; the command is then sent to the spindle servo driver. If the current cycle detects a negative moving speed, the industrial control computer 18 will no longer use the deceleration logic, but will switch to the acceleration logic, and at the same time issue a spindle speed increase command and a feed speed increase command. In order to avoid repeatedly switching between acceleration and deceleration states when the moving speed is close to zero, the industrial control computer 18 can set a speed judgment dead zone. Whenever the moving speed is within the range of this dead zone, it will be treated as zero speed state, and the current spindle speed and the pressing speed of the feed hydraulic cylinder 4 will be maintained. This allows for clear boundaries between the three states: negative moving speed, zero moving speed, and positive moving speed that does not increase continuously, reducing malfunctions caused by encoder pulsation, saw blade jumping, or cutting fluid scouring. In this embodiment, the spindle speed compensation is not used to directly represent a certain absolute cutting force value, but rather to represent the correction requirement of the saw blade linear speed due to the changing trend of cutting resistance. Logically, it includes three parts: trend identification, compensation amount generation, and speed command correction. The trend recognition section receives the moving speed and the rate of change of speed and outputs the state results: resistance continues to increase, resistance decreases, or the trend is not obvious; the compensation amount generation section generates a deceleration compensation value based on the speed compensation coefficient when the resistance continues to increase; the speed command correction section selects deceleration, acceleration, or maintenance based on the state results. The logical structure represents the following physical relationship: when the material cross-section gradually becomes thicker or the saw blade cuts into a larger contact area, the upward movement speed of the guide arm and its increasing trend will be more obvious, and the corresponding saw tooth load-bearing growth trend will be stronger. Therefore, the linear speed should be reduced in advance. When the material cross-section becomes thinner or cuts into a cavity, the guide arm falls back, indicating that the cutting resistance per unit time has decreased. At this time, increasing the linear speed and feed rate can restore the machining efficiency. The aforementioned reduction in linear speed, resulting in a decrease in the volume of material involved in cutting per unit time, refers to the fact that in the short period before the feed adjustment has completely eliminated the upward trend of resistance, the spindle speed reduction can reduce the cycle time of the saw teeth entering the cutting zone and the instantaneous cutting impact, thereby suppressing the trend of force growth, rather than relying solely on the spindle speed reduction to define the final amount removed. Therefore, this implementation method and the feed deceleration are synergistic. The former mainly suppresses the trend of resistance growth, while the latter mainly corrects the current excessive force. The combination of the two can make the constant force control logic more self-consistent. To ensure that the trend judgment logic is clear and feasible, a quantitative deduction example of speed compensation is provided here: the sampling period of the industrial control computer 18 is set to 20ms, the current speed of the spindle servo motor 8 is 800r / min, and the speed compensation coefficient is set to 20 (r / min) / (mm / s²). If the moving speeds measured in three consecutive sampling cycles are 1.0 mm / s, 1.2 mm / s, and 1.4 mm / s respectively, satisfying the condition that the speed is positive and continuously increasing, the industrial control computer 18 calculates that the speed difference between adjacent cycles is 0.2 mm / s. Dividing this by the sampling cycle of 0.02 s, the speed change rate is extracted as 10 mm / s². The industrial control computer 18 multiplies the speed change rate 10 by the speed compensation coefficient 20 to obtain a speed compensation value of 200 r / min; the industrial control computer 18 subtracts 200 from the current speed 800 to generate a new command of 600 r / min and sends it to the spindle servo motor 8; through the above calculation process, the industrial control computer 18 can accurately generate and output the corresponding speed correction command for the spindle servo motor 8.

[0028] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mechanically adaptive band saw with constant cutting force, characterized in that, include: The feed drive unit includes a base, a vertical column located on top of it, a feed hydraulic cylinder, and a feed slide that is slidably connected to the side of the vertical column. The feed hydraulic cylinder drives the feed slide to move up and down along the vertical column. The sawing function unit is connected to the side of the feed slide and driven by the feed drive unit. It includes a horizontal saw bow, a spindle servo motor, a drive wheel, a driven wheel, and a ring saw blade. The drive wheel and the driven wheel are located at the inner end of the horizontal saw bow. The ring saw blade is tensioned between the two wheels. The spindle servo motor drives the drive wheel to rotate. The mechanical adaptive measurement unit is located at the bottom of the horizontal saw bow and includes a fixed guide arm, a floating guide arm, a helical compression spring, and a displacement detection assembly. The fixed guide arm is fixed to the side of the horizontal saw bow near the drive wheel, and the floating guide arm slides along a linear guide rail to the side of the horizontal saw bow near the driven wheel. The helical compression spring abuts against the displacement detection assembly, which is connected between the horizontal saw bow and the floating guide arm. When the annular saw blade is subjected to cutting reaction force, it drives the floating guide arm to overcome the elastic force of the helical compression spring and slide upward along the linear guide rail. An industrial control computer is communicatively connected to the feed hydraulic cylinder, the spindle servo motor, and the displacement detection component, and is used to control the feed drive unit, the sawing function unit, and the mechanical adaptive measurement unit.

2. The mechanically adaptive band saw with constant cutting force according to claim 1, characterized in that, The displacement detection assembly includes a rack fixed to the side of the floating guide arm, a measuring gear rotatably connected to the side wall of the horizontal saw bow, and a photoelectric encoder connected to the shaft of the measuring gear, wherein the measuring gear meshes with the rack.

3. The mechanically adaptive band saw with constant cutting force according to claim 2, characterized in that, The top of the floating guide arm is machined with a spring guide post, and the spiral compression spring is sleeved on the outside of the spring guide post. The top end of the spiral compression spring abuts against the inner wall of the horizontal saw bow. The preload of the spiral compression spring is set to a preset reference value greater than zero so that the floating guide arm remains in the reference position when the ring saw blade is unloaded.

4. The mechanically adaptive band saw with constant cutting force according to claim 1, characterized in that, Both the fixed guide arm and the floating guide arm have clamping grooves machined at their bottom ends. Carbide guide blocks are fixed in the clamping grooves, and the annular saw blade passes through the gap between the carbide guide blocks.

5. The mechanically adaptive band saw with constant cutting force according to claim 2, characterized in that, The spindle servo motor's shaft is directly connected to the drive wheel via a plum blossom coupling. The photoelectric encoder's housing is fixed to the side wall of the horizontal saw bow via a flange. The photoelectric encoder is connected to the measuring gear's shaft via a cross-slider coupling.

6. The mechanically adaptive band saw with constant cutting force according to claim 1, characterized in that, The extension direction of the linear guide is parallel to the feed direction of the feed hydraulic cylinder.

7. The mechanically adaptive band saw with constant cutting force according to claim 1, characterized in that, The vertical column is machined with dovetail guide rails on its side, the feed slide is slidably connected to the dovetail guide rails, and the piston rod of the feed hydraulic cylinder has a preset stroke to meet the height requirements of the material to be cut.

8. A control method, applied to the mechanical adaptive band saw with constant cutting force as described in claim 1, characterized in that, include: S1. Control the spindle servo motor to drive the drive wheel to rotate, thereby driving the ring saw blade to rotate, and control the feed hydraulic cylinder to drive the horizontal saw bow to move downward. S2. Control the displacement detection component to record the zero coordinates when the floating guide arm is at the extreme position of the lower end of the linear guide rail; S3. When the ring saw blade contacts the material to be cut and generates a cutting reaction force that causes the floating guide arm to slide, the displacement detection component is controlled to continuously record measurement data within a set sampling period and calculate the actual upward displacement of the floating guide arm. S4. Calculate the moving speed and speed change trend of the floating guide arm based on the actual upward displacement of the adjacent sampling cycles; calculate the actual upward displacement of the current cycle, the stiffness coefficient of the pre-acquired helical compression spring, and the initial preload to calculate the actual cutting force borne by the ring saw blade. S5. Compare the actual cutting force with the preset target constant cutting force. When the actual cutting force is greater than the target constant cutting force, reduce the downward pressing speed of the feed hydraulic cylinder. When the actual cutting force is equal to or less than the target constant cutting force, if the moving speed of the floating guide arm is zero or positive but does not continue to increase, maintain the downward pressing speed of the feed hydraulic cylinder. S6. When the moving speed is positive and continues to increase, reduce the speed of the spindle servo motor; when the actual cutting force is equal to or less than the target constant cutting force and the moving speed is negative, increase the speed of the spindle servo motor and simultaneously increase the downward pressing speed of the feed hydraulic cylinder. S7. Repeat the steps from controlling the displacement detection component to record measurement data to maintaining the rotational speed of the spindle servo motor and the pressing speed of the feed hydraulic cylinder.

9. The control method according to claim 8, characterized in that, The feed hydraulic cylinder is connected to a servo proportional valve; When the actual cutting force is greater than the target constant cutting force, the difference between the actual cutting force and the target constant cutting force is multiplied by a preset proportional coefficient to obtain the speed reduction amount. The current downward pressing speed of the feed hydraulic cylinder is subtracted from the speed reduction amount, which is then sent to the servo proportional valve as a new feed command to reduce the downward pressing speed.

10. The control method according to claim 8, Its features are, When the moving speed is positive and continues to increase, the speed change rate of the moving speed is extracted, the speed change rate is multiplied by a preset speed compensation coefficient, and the compensation value is subtracted from the current speed of the spindle servo motor to reduce the linear speed of the ring saw blade. When the moving speed is negative, an acceleration command is issued to simultaneously increase the pressing speed of the feed hydraulic cylinder and the rotation speed of the spindle servo motor.

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