Cutting device and method with positioning function for high-speed rail accessory manufacturing

Abstract

The invention relates to the technical field of high-speed rail accessory manufacturing, and discloses a high-speed rail accessory manufacturing cutting device and method.The high-speed rail accessory manufacturing cutting device comprises a five-axis mechanical arm, a laser cutting head is arranged at the moving end of the five-axis mechanical arm, a plurality of magnetic adsorption mechanisms are arranged on mounting bases, and the two mounting bases are arranged close to the left side and the right side of a steel plate correspondingly; and the lower surface of the steel plate is magnetically adsorbed on the magnetic adsorption mechanisms on the two mounting seats. The steel plate is adsorbed from the bottom face of the steel plate through the magnetic adsorption mechanism, the steel plate is not clamped and damaged, deformation is avoided, the distance between the two installation bases can be adjusted through the air cylinder, and then the steel plate clamping device is suitable for steel plates of different sizes. In order to solve the problem of contour thermal deformation caused by laser cutting, a sample plate of a steel plate is firstly cut before cutting, then the thermal deformation amount of the steel plate at different cutting speeds and different laser power is obtained, when cutting parameters are set, the set power and speed can be compensated and corrected based on the thermal deformation amount, and the rejection rate can be greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of high-speed rail component manufacturing technology, and in particular to a cutting device and method for manufacturing high-speed rail components with positioning function. Background Technology

[0002] Among various high-speed rail components, steel plates are a common structural form. During manufacturing, the steel plates need to be cut into the required shapes using lasers, such as weight-reducing window frames and bayonet openings. Before cutting, the steel plate is first clamped and fixed using fixtures. After determining the cutting position, laser cutting is performed. This process has the following technical drawbacks:

[0003] 1. Different sizes of steel plates require different rigid fixtures to be made. Once the steel plate is reshaped, the fixtures need to be reassembled and the positioning needs to be calibrated, which is inefficient. In addition, the clamping force of the rigid fixtures can easily cause the steel plate to deform.

[0004] 2. The heat generated during laser cutting can cause thermal deformation of the cutting contour, which will result in contour deviation after cooling, thus leading to a high scrap rate.

[0005] In view of this, how to provide a laser cutting device that can partially or completely overcome the above-mentioned technical defects is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a cutting device and method for manufacturing high-speed rail components with positioning function, so as to solve the problems existing in the prior art.

[0007] To achieve the above objectives, the present invention provides a cutting device for manufacturing high-speed rail components with positioning function, comprising:

[0008] A five-axis robotic arm, with a laser cutting head mounted on its moving end, the laser cutting head being connected to a laser generator via an optical path;

[0009] Two mounting bases are provided, each equipped with multiple magnetic adsorption mechanisms. The two mounting bases are positioned close to the left and right sides of the steel plate, respectively. The lower surface of the steel plate is magnetically adsorbed onto the magnetic adsorption mechanisms on the two mounting bases. The five-axis robotic arm is used to drive the laser cutting head to move above the steel plate and cut it.

[0010] Furthermore, the magnetic adsorption mechanism includes:

[0011] The electromagnetic column has a magnetic surface at the top and a power supply module that is electrically connected to the magnetic surface inside. When the power supply module supplies power to the magnetic surface, the magnetic surface generates magnetism and can attract the bottom surface of the steel plate.

[0012] Furthermore, an elastic connector is provided on the magnetic surface, and the upper surface of the elastic connector is a hemispherical surface.

[0013] Furthermore, it also includes:

[0014] The slide rail, the mounting base includes a first mounting base and a second mounting base, the first mounting base is slidably connected to the slide rail, and the second mounting base is fixed on the slide rail;

[0015] A drive mechanism, connected to the first mounting base, is used to drive the first mounting base to slide along the slide rail, moving closer to or away from the second mounting base.

[0016] Furthermore, the driving mechanism is a cylinder.

[0017] Furthermore, the mounting base is equipped with multiple telescopic motors, each corresponding to a multiple electromagnetic column. The mounting base has mounting holes, through which the bottom of the electromagnetic column passes and connects to the output end of the telescopic motor. The telescopic motor is used to drive the electromagnetic column to move up and down.

[0018] Furthermore, the steel plate is flat or curved.

[0019] Furthermore, it also includes:

[0020] A stripe projector is positioned above the steel plate;

[0021] Two industrial cameras are positioned on the front and rear sides of the stripe projector, respectively, to jointly acquire images of the steel plate through the stripe projector and the two industrial cameras.

[0022] This invention also provides a cutting method for manufacturing high-speed rail components with positioning function, which uses a cutting device for manufacturing high-speed rail components with positioning function and includes the following steps:

[0023] S1: Adjust the distance between the first mounting base and the second mounting base according to the length of the steel plate so that the electromagnetic columns on both mounting bases are located on the lower surface of the steel plate; adjust the height of multiple electromagnetic columns by telescopic motor so that the elastic connectors on each electromagnetic column are in contact with the lower surface of the steel plate; supply power to the magnetic surface through the power supply module so that the steel plate is attracted to the electromagnetic columns and the target cutting position is located in the area between the two mounting bases.

[0024] S2: Images of the steel plate are acquired using a stripe projector and two industrial cameras. The images are then fused to obtain the complete point cloud of the steel plate. The point cloud of the steel plate is aligned with the 3D model of the standard steel plate part. Point sets with height abrupt changes > 0.2 mm and normal angles > 15° are extracted to obtain the true edge of the steel plate.

[0025] S3: Before laser cutting, a template of the same thickness as the steel plate is made. The template is cut with lasers of different power and speed, and the thermal rebound of the template is recorded. The power-thermal rebound curve and the speed-thermal rebound curve are obtained and stored in the CNC system database.

[0026] S4: The power and speed of laser cutting are set through the CNC system. Based on the set power and speed, the corresponding thermal rebound amount of the steel plate is obtained. The CNC system compensates and corrects the set power and speed according to the thermal rebound amount to obtain the actual laser cutting power and speed.

[0027] S5: Based on the actual edge of the steel plate, the target cutting position, and the cutting shape obtained in step S2, confirm the movement path of the laser cutting head. The CNC system controls the five-axis robot to drive the laser cutting head to perform laser cutting on the steel plate according to the movement path of the laser cutting head, the actual laser cutting power, and the speed.

[0028] Furthermore, in step S4, the CNC system corrects the set power and speed rules according to the thermal rebound compensation as follows:

[0029] When the thermal rebound is greater than 0.3mm, the cutting power is 2kW and the cutting speed is 8m / min;

[0030] When the thermal rebound is 0.15 < 0.3 mm, the cutting power is 2.5 kW and the cutting speed is 12 m / min.

[0031] When the thermal rebound is ≤0.15mm, the cutting power is 3kW and the cutting speed is 18m / min.

[0032] The present invention discloses the following technical effects:

[0033] 1. This invention uses a magnetic adsorption mechanism to adsorb the steel plate from the bottom surface, without clamping damage or deformation. Furthermore, the magnetic adsorption mechanism is arranged on two mounting bases, and the distance between the two mounting bases can be adjusted by a cylinder to accommodate steel plates of different sizes. When the steel plate is reshaped, it is no longer necessary to replace different fixing mechanisms, thus improving the cutting efficiency of the steel plate.

[0034] 2. To address the issue of contour thermal deformation caused by laser cutting, this invention first cuts a template of the steel plate before cutting to obtain the amount of thermal deformation of the steel plate under different cutting speeds and laser powers. When setting cutting parameters, the power and speed can be adjusted based on the amount of thermal deformation to obtain the actual laser cutting power and speed, ensuring that the amount of contour deformation is within the preset range. In this way, the thermal deformation problem after laser cutting is effectively controlled, which can significantly reduce the scrap rate. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of the present invention;

[0037] Figure 2 This is a sectional view of the second mounting bracket portion;

[0038] Among them, 1. Five-axis robot; 2. Laser cutting head; 3. Magnetic adsorption mechanism; 301. Electromagnetic column; 302. Magnetic adsorption surface; 303. Elastic connector; 4. Steel plate; 5. Slide rail; 6. First mounting base; 7. Second mounting base; 8. Drive mechanism; 9. Telescopic motor. Detailed Implementation

[0039] Among the existing technologies retrieved, CN118357483A discloses a cutting device for manufacturing high-speed rail parts with positioning function. The device discloses the following: During use, the parts are placed on a worktable. A movable positioning fixture positions and fixes the parts on the worktable. The main spindle drives a boring bar to rotate, causing the boring bar head to drive a first boring tool to rotate, cutting and drilling the parts. When the first boring tool is damaged from prolonged grinding and needs replacement, a first electric push rod is activated to move a baffle, causing the baffle to move into the mounting groove away from the first movable opening, exposing the first movable opening. Then, a first motor is activated to drive a rotating rod and gear to rotate, causing the gear to drive a rack to move. The moving block moves on the support block, causing the first boring bar to move into the mounting slot. The second boring bar moves to the outside of the mounting slot through the first movable opening. The main spindle component drives the boring bar and boring head to rotate, allowing the second boring bar to continue grinding. When different styles and functions of holes need to be drilled, the second boring bar is removed, and the second electric push rods on the upper and lower sides of the connecting block are activated, causing the second electric push rods to move up and down respectively, pushing the fixed plate to move out of the second movable opening. The movement of the fixed plate simultaneously causes the telescopic rod to retract, causing the fixed plate to move the third boring bar connected to one side out of the second movable opening to the outside of the boring bar head. When the boring bar and boring bar head rotate, the third boring bar rotates to grind and cut.

[0040] When grinding and cutting parts, debris will get tangled on the boring bar head. When switching between the first, second, and third boring tools, the second motor is started first to drive the threaded rod to rotate. Through the action of the limit rod, the threaded block moves downward along the threaded rod, causing the movable plate to rotate and press against the moving plate. The moving plate moves along the inner wall of the mounting block, and the movable plate drives the pressing rod to move out of the second movable opening. The pressing rod presses the pressing plate into the groove on one side of the baffle, which compresses the connecting spring. The pressing plate presses against the mounting plate, causing the mounting plate to drive the cutting blade to move outward from the first movable opening. When the pressing... When the insert rod on one side of the plate is inserted into the slot inside the groove, the position of the cutting blade is fixed. When the first electric push rod moves the baffle, the extrusion plate moves the extrusion rod, causing the slider at the bottom of the mounting block to move in the groove. This allows the cutting blade to cut the debris wrapped around the boring bar head as the baffle moves. After cutting, the first electric telescopic rod is activated to push the ring along the outer wall of the boring bar head, so that the pushing ring removes the debris remaining on the boring bar head, thereby keeping the boring bar head clean and facilitating the switching of the first boring bar, the second boring bar, and the third boring bar.

[0041] As can be seen from the above, the core idea of ​​this existing technology is to prevent the boring tool from being damaged by grinding after prolonged use by replacing the boring tool. Regarding the clamping, it uses movable clamps to hold the workpiece to be cut from both sides. However, many steel plates in high-speed rail components are relatively thin, making it difficult to clamp them using this type of clamp. Furthermore, the cutting accuracy of the boring tool is far lower than that of laser cutting, and it also introduces vibration cutting errors. When cutting precision structures such as weight-reducing window frames and bayonet joints, the boring tool cannot meet the cutting accuracy requirements of high-speed rail components.

[0042] In summary, the existing technology has not yet been able to solve the technical defects mentioned in the background technology.

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0044] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0045] like Figures 1 to 2 As shown, the present invention provides a cutting device for manufacturing high-speed rail components with positioning function, comprising:

[0046] A five-axis robotic arm 1 has a laser cutting head 2 mounted on its moving end, and the laser cutting head 2 is connected to a laser generator via an optical path.

[0047] Two mounting bases are provided, each equipped with multiple magnetic adsorption mechanisms 3. The two mounting bases are positioned close to the left and right sides of the steel plate 4, respectively. The lower surface of the steel plate 4 is magnetically adsorbed onto the magnetic adsorption mechanisms 3 on the two mounting bases. The five-axis robot 1 is used to drive the laser cutting head 2 to move above the steel plate 4 and cut it.

[0048] In this embodiment, the steel plate 4 is a thin plate with a length of 2 to 4 m, a width of 0.8 to 1.5 m, and a thickness of 2 to 4 mm.

[0049] In this embodiment, the five-axis robot 1 can move along the X, Y, and Z axes, rotate along the A axis, and swing along the C axis. Specifically, the linear travel of the X and Y axes is 3000mm * 1500mm, the travel of the Z axis is 300mm, the A axis can rotate 135°, and the C axis can swing 360°. The laser generator is an IPG, 3kW, with a wavelength of 1.07μm and an optical fiber core diameter of 50μm.

[0050] In this embodiment, the magnetic adsorption mechanism 3 includes:

[0051] The electromagnetic column 301 has a magnetic surface 302 at its top and a power supply module that is electrically connected to the magnetic surface 302 inside. When the power supply module supplies power to the magnetic surface 302, the magnetic surface 302 generates magnetism and can attract the bottom surface of the steel plate 4.

[0052] In this embodiment, an elastic connector 303 is provided on the magnetic surface 302, and the upper surface of the elastic connector 303 is hemispherical. The elastic connector 303 is made of an elastic material that does not affect the magnetism, and can adapt to the lower surface of the curved steel plate 4 and generate elastic deformation accordingly, thereby improving the connection stability. It should be noted that the elasticity of the elastic connector 303 is much less than the magnetism of the magnetic surface 302.

[0053] In this embodiment, it also includes:

[0054] The slide rail 5 and the mounting base include a first mounting base 6 and a second mounting base 7. The first mounting base 6 is slidably connected to the slide rail 5, and the second mounting base 7 is fixed on the slide rail 5.

[0055] The drive mechanism 8 is connected to the first mounting base 6 and is used to drive the first mounting base 6 to slide along the slide rail 5, moving closer to or away from the second mounting base 7.

[0056] In this embodiment, the drive mechanism 8 is a cylinder, which is mounted on the base. The base and the slide rail 5 are arranged on the same plane.

[0057] In this embodiment, a plurality of telescopic motors 9 are provided in the mounting base, and the plurality of telescopic motors 9 correspond one-to-one with a plurality of electromagnetic columns 301. The mounting base is provided with mounting holes, and the bottom of the electromagnetic column 301 passes through the mounting holes and is connected to the output end of the telescopic motor 9. The telescopic motor 9 is used to drive the electromagnetic column 301 to move up and down.

[0058] In this embodiment, the steel plate 4 is flat or curved.

[0059] In this embodiment, it also includes:

[0060] A stripe projector is positioned above steel plate 4;

[0061] Two industrial cameras are positioned on the front and rear sides of the stripe projector, respectively, to jointly acquire images of the steel plate 4 through the stripe projector and the two industrial cameras.

[0062] The two industrial cameras are positioned at an angle of 30° to the vertical direction, with a reference distance of 800mm. The stripe projector has a projection stripe period of 0.5mm and a single shooting area of ​​1200mm×800mm. The combination of the three can acquire a complete point cloud of steel plate 4 with a point cloud density of 0.2mm / point.

[0063] In this embodiment, a bracket can be set above the steel plate 4 for mounting a stripe projector and an industrial camera.

[0064] This invention also provides a cutting method for manufacturing high-speed rail components with positioning function, which uses a cutting device for manufacturing high-speed rail components with positioning function and includes the following steps:

[0065] S1: Adjust the distance between the first mounting base 6 and the second mounting base 7 according to the length of the steel plate 4, so that the electromagnetic columns 301 on both mounting bases are located on the lower surface of the steel plate 4; adjust the height of the multiple electromagnetic columns 301 by the telescopic motor 9, so that the elastic connectors 303 on each electromagnetic column 301 are in contact with the lower surface of the steel plate 4; supply power to the magnetic surface 302 by the power supply module, so that the steel plate 4 is attracted to the electromagnetic columns 301, and the target cutting position is located in the area between the two mounting bases;

[0066] S2: Images of steel plate 4 are acquired using a stripe projector and two industrial cameras. After image fusion processing, the complete point cloud of steel plate 4 is obtained. The point cloud of steel plate 4 is aligned with the 3D model of the standard part of steel plate 4. Point sets with height abrupt change > 0.2 mm and normal angle > 15° are extracted to obtain the true edge of steel plate 4.

[0067] S3: Before laser cutting, a template with the same thickness as steel plate 4 is made. The template is cut with lasers of different power and speed, and the thermal rebound of the template is recorded. The power-thermal rebound curve and the speed-thermal rebound curve are obtained and stored in the CNC system database.

[0068] S4: The power and speed of laser cutting are set by the CNC system. Based on the set power and speed, the corresponding thermal rebound amount of steel plate 4 is obtained. The CNC system compensates and corrects the set power and speed according to the thermal rebound amount to obtain the actual laser cutting power and speed.

[0069] S5: Based on the actual edge of the steel plate 4, the target cutting position, and the cutting shape obtained in step S2, the moving path of the laser cutting head 2 is confirmed. The CNC system controls the five-axis robot 1 to drive the laser cutting head 2 to perform laser cutting on the steel plate 4 according to the moving path of the laser cutting head 2, the actual laser cutting power, and the speed.

[0070] In this embodiment, in step S4, the CNC system corrects the set power and speed rules according to the thermal rebound compensation as follows:

[0071] When the thermal rebound is greater than 0.3mm, the cutting power is 2kW and the cutting speed is 8m / min;

[0072] When the thermal rebound is 0.15 < 0.3 mm, the cutting power is 2.5 kW and the cutting speed is 12 m / min.

[0073] When the thermal rebound is ≤0.15mm, the cutting power is 3kW and the cutting speed is 18m / min.

[0074] In this embodiment, the CNC system uses a Beckhoff CX2040 industrial computer + TwinCAT3NCPTP5-axis. The power-thermal rebound curve and speed-thermal rebound curve are stored in an industrial SSD and retained even after power failure.

[0075] Upon testing, the steel plate 4 cut using this embodiment has a cutting profile of ≤0.15mm, which meets the requirements of high-speed rail grade 0 flatness (0.2mm / 1000mm).

[0076] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0077] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A cutting device for high-speed rail fitting manufacturing with positioning function, characterized in that, Include: Five-axis manipulator (1), which is provided with a laser cutting head (2) on the moving end, the laser cutting head (2) is connected with a laser generator through an optical path; Two mounting seats, a plurality of magnetic adsorption mechanisms (3) are arranged on the mounting seat, two mounting seats are arranged near the left and right sides of the steel plate (4) respectively, the lower surface of the steel plate (4) is magnetically adsorbed on the magnetic adsorption mechanism (3) on the two mounting seats, and the five-axis manipulator (1) is used to drive the laser cutting head (2) to move above the steel plate (4) and cut it.

2. The cutting device with positioning function for high-speed rail accessory manufacturing according to claim 1, characterized in that, The magnetic adsorption mechanism (3) comprises: An electromagnetic column (301), the top of which is a magnetic surface (302), and an internal power supply module is arranged in the electromagnetic column (301) and electrically connected with the magnetic surface (302), when the power supply module supplies power to the magnetic surface (302), the magnetic surface (302) generates magnetism and can adsorb the bottom surface of the steel plate (4).

3. The cutting device with positioning function for high-speed rail accessory manufacturing according to claim 2, characterized in that, The magnetic surface (302) is provided with an elastic connecting piece (303), and the upper surface of the elastic connecting piece (303) is a hemispherical surface.

4. The cutting device with positioning function for high-speed rail accessory manufacturing according to claim 3, characterized in that, Further comprising: A slide rail (5), the mounting seat comprises a first mounting seat (6) and a second mounting seat (7), the first mounting seat (6) is in sliding connection with the slide rail (5), and the second mounting seat (7) is fixed on the slide rail (5); A driving mechanism (8) connected with the first mounting seat (6) is used to drive the first mounting seat (6) to slide along the slide rail (5) and approach or move away from the second mounting seat (7).

5. The cutting device with positioning function for manufacturing high-speed rail fittings according to claim 4, characterized in that, The driving mechanism (8) is a gas cylinder.

6. The cutting device with positioning function for high-speed rail accessory manufacturing according to claim 4, characterized in that, A plurality of telescopic motors (9) are arranged in the mounting seat, the plurality of telescopic motors (9) correspond to the plurality of electromagnetic columns (301) one by one, a mounting hole is formed in the mounting seat, the bottom of the electromagnetic column (301) penetrates through the mounting hole and is connected with the output end of the telescopic motor (9), and the telescopic motor (9) is used to drive the electromagnetic column (301) to move up and down.

7. The cutting device with positioning function for high-speed rail accessory manufacturing according to claim 6, characterized in that, The steel plate (4) is flat or arc-shaped.

8. The cutting device with positioning function for high-speed rail accessory manufacturing according to claim 7, characterized in that, Further comprising: A stripe projector is arranged above the steel plate (4); Two industrial cameras are arranged on the front and back of the stripe projector respectively, and the images of the steel plate (4) are collected by the stripe projector and the two industrial cameras.

9. A cutting method for manufacturing a high-speed rail fitting having a positioning function, characterized by, The cutting device with positioning function for manufacturing high-speed rail accessories according to claim 8 comprises the following steps: S1: adjust the distance between the first mounting seat (6) and the second mounting seat (7) according to the length of the steel plate (4), so that the electromagnetic columns (301) on the two mounting seats are located on the lower surface of the steel plate (4); adjust the height of the plurality of electromagnetic columns (301) through the telescopic motor (9), so that the elastic connecting piece (303) on each electromagnetic column (301) is in contact with the lower surface of the steel plate (4); power is supplied to the magnetic surface (302) through the power supply module, so that the steel plate (4) is adsorbed on the electromagnetic column (301), and the target cutting position is located in the region between the two mounting seats; S2: Collect the image of the steel plate (4) by the stripe projector and two industrial cameras, get the complete point cloud of the steel plate (4) after image fusion processing, align the point cloud of the steel plate (4) with the three-dimensional model of the standard part of the steel plate (4), extract the point set with a height mutation >0.2mm and a normal angle >15°, and get the real edge of the steel plate (4); S3: Before laser cutting, a sample plate with the same thickness as the steel plate (4) is made, and the sample plate is cut at different powers and different speeds, and the thermal springback amount of the sample plate is recorded, the power-thermal springback amount curve and the speed-thermal springback amount curve are obtained and stored in the numerical control system database; S4: Set the power and speed of laser cutting through the numerical control system, obtain the corresponding thermal springback amount of the steel plate (4) based on the set power and speed, and the numerical control system compensates and corrects the set power and speed according to the thermal springback amount, to obtain the actual power and speed of laser cutting; S5: According to the real edge of the steel plate (4) obtained in step S2 and the target cutting position and cutting shape, the moving path of the laser cutting head (2) is confirmed, and the numerical control system controls the five-axis manipulator (1) to drive the laser cutting head (2) to cut the steel plate (4) according to the moving path of the laser cutting head (2), the actual power and speed of laser cutting.

10. The cutting method for high-speed rail fitting manufacturing with positioning function according to claim 9, characterized in that, In step S4, the rule for the numerical control system to compensate and correct the set power and speed according to the thermal springback amount is: when the thermal springback amount is >0.3mm, the cutting power is 2kW and the cutting speed is 8m / min; When the thermal springback amount is 0.15mm, the cutting power is 3kW and the cutting speed is 18m / min.

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