Control method for continuously cutting metal sheet blank

Abstract

The invention discloses a control method for continuously cutting a metal sheet blank, which comprises the following steps of: arranging at least two laser cutting devices which are provided with at least two laser cutting heads which can move in a conveying direction X and a Y direction vertical to the conveying direction; and the numerical control system is used for controlling the laser cutting head to move along a cutting path corresponding to the preset contour. A first distance measuring device arranged on the upstream of a laser cutting device is used for continuously measuring a first distance value between a first strip edge of a metal sheet strip in the Y direction and a fixed first measuring point, and the measured first distance value is sent to a numerical control system. And continuously measuring a second distance value between a second strip edge of the metal sheet strip in the Y direction and a fixed second measuring point through a second distance measuring device arranged at the downstream of the laser cutting device, and sending the measured second distance value to the numerical control system. A corrected cutting path is calculated by a control program of the numerical control system using the predetermined cutting path and the measured first and second distance values, and a kerf is generated in the sheet metal strip by moving the laser cutting head along the corrected cutting path.

Description

Technical Field

[0001] The invention relates to the technical field of material processing, and in particular to a control method for continuously cutting a metal sheet blank. Background Art

[0002] In laser blanking equipment, the metal sheet strip is in continuous motion, and each laser head performs dynamic cycle cutting on the sheet strip. The metal sheet strip is subjected to external force in the y direction perpendicular to the conveying direction, and cannot maintain linear motion. It swings left and right in the y direction perpendicular to the conveying direction, resulting in the inability of the cutting pattern to form a closed cutting path when the multi-zone laser heads cooperate in blanking. Summary of the invention

[0003] In view of the above technical problems, the present invention provides a control method for continuously cutting metal sheet blanks.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A control method for continuously cutting a metal sheet blank comprises the following steps:

[0006] S1. Arrange multiple laser cutting heads along the transmission direction of the plate, and divide the closed cutting track of the plate processing pattern into segmented cutting tracks of multiple processing areas;

[0007] S2. Use a numerical control system to control the movement of the laser cutting head, that is, control the movement speed of the laser cutting head in the X-axis direction of the plate transmission direction, and control the movement speed of the laser cutting head in the Y-axis direction perpendicular to the X-axis;

[0008] S3, continuously measuring a first distance value between a first strip edge of the plate and a first fixed measuring point in the Y-axis direction, and a second distance value between a second strip edge of the plate and a second fixed measuring point in the Y-axis direction, and sending the first distance value and the second distance value to the numerical control system in real time;

[0009] S4. The numerical control system calculates a corrected cutting path using the predetermined cutting path and the measured first distance value and second distance value, and generates a cut in the plate by moving the laser cutting head along the corrected cutting path.

[0010] As a preferred embodiment of the above solution, in step S1, the plate is transported forward along the transport direction X-axis by multiple sets of belt conveyors.

[0011] As a preferred embodiment of the above solution, a light-transmitting slit is provided on the belt conveyor for passing the laser.

[0012] As a preferred embodiment of the above scheme, each laser cutting head is individually controlled by a set of three-axis transmission mechanisms, and the three-axis transmission mechanism can drive the laser cutting head to move along the X-axis, Y-axis, and Z-axis directions, and the X-axis, Y-axis, and Z-axis are perpendicular to each other in three-dimensional space.

[0013] As a preferred embodiment of the above scheme, in step S2, the CNC system controls the actual movement speed of the laser cutting head in the X-axis direction to be equal to the sum of the movement speed of the plate along the conveyor belt direction and the set speed of the laser cutting head in the X-axis direction when the plate is stationary to process the set trajectory. The CNC system controls the actual movement speed of the laser cutting head in the Y-axis direction to be equal to the set speed of the laser cutting head in the Y-axis direction when the plate is stationary to process the set trajectory.

[0014] As a preferred embodiment of the above scheme, in step S3, the first distance value and the second distance value are measured by a first distance measuring device arranged upstream of the laser cutting device and a second distance measuring device arranged downstream of the laser cutting device, respectively, and the measured values ​​are sent to the numerical control system in real time.

[0015] As a preferred embodiment of the above scheme, in step S4, the displacement compensation value of the laser cutting head in the Y direction and the rotation angle compensation value in the X direction are calculated according to the following formula (1):

[0016]

[0017] The first measuring point is set at a fixed position in the entrance area of ​​the first cutting processing area, and the small displacement a(t) at the first measuring point is measured in millimeters. In formula (1), a(t i )、a(t n ) are the initial sampling time t i time, at t i The sampling time after t n At the sampling value of time (where n ranges from j to infinity), the metal sheet strip moves from left to right to the processing area, and the first distance a(t i ) as the initial sampling time, and the initial sampling time t i The measured value a(t i ) as the reference value;

[0018] A second measuring point is set at a fixed position in the entrance area of ​​the second cutting processing area, and the small displacement b(t) at the second measuring point is measured in millimeters. In formula (1), b(t j )、b(t n ) are the initial sampling time t j time, at t j The sampling time after t nAt the sampling value of time (where n is from j to infinity), the metal sheet strip moves from left to right to the processing area, and the second distance value b (t j ) as the initial sampling time, and the initial sampling time t j The measured value b(t j ) as the reference value;

[0019] In formula (1), m is the vertical distance between the first measuring point and the second measuring point along the X-axis direction, which is a constant value in millimeters. The first measuring point and the second measuring point are not necessarily on a straight line along the X-axis direction. k1 and k2 are respectively n At the moment, the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction of the two areas is in millimeters, and α is the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction at the moment, and the unit is in millimeters. n At this moment, the laser cutting head processing set trajectory of the two areas is the rotation angle compensation value of the angle between the positive direction of the X axis.

[0020] As a preferred embodiment of the above scheme, during the first cutting, the machining coordinate system is manually calibrated to perform displacement compensation in the X and Y directions to close the cutting pattern. During the subsequent dynamic cycle cutting, the CNC system converts the displacement compensation value and the rotation angle compensation value into G code. The converted G code uses the displacement compensation value and the rotation angle compensation value to perform displacement compensation in the Y direction and rotation angle compensation on the machining coordinate system in the positive direction of the X-axis. The converted G code performs real-time compensation for the rotation angle of the laser cutting head processing setting trajectory in the first cutting processing area and the second cutting processing area in the Y direction and the positive direction of the X-axis.

[0021] Due to the above structure, the beneficial effects of the present invention are:

[0022] By utilizing the method provided by the present invention, a metal sheet blank with a predetermined contour can be cut safely and reliably from a continuously conveyed metal sheet strip. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below.

[0024] Figure 1 It is a work flow chart of the present invention;

[0025] Figure 2 It is a schematic diagram of the working principle of the present invention. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.

[0027] like Figure 1 , Figure 2 As shown, a control method for continuously cutting a metal sheet blank comprises the following steps:

[0028] S1. Arrange multiple laser cutting heads along the transmission direction of the plate, and divide the closed cutting track of the plate processing pattern into segmented cutting tracks of multiple processing areas;

[0029] S2. Use a numerical control system to control the movement of the laser cutting head, that is, control the movement speed of the laser cutting head in the X-axis direction of the plate transmission direction, and control the movement speed of the laser cutting head in the Y-axis direction perpendicular to the X-axis;

[0030] S3, continuously measuring a first distance value between a first strip edge of the plate and a first fixed measuring point in the Y-axis direction, and a second distance value between a second strip edge of the plate and a second fixed measuring point in the Y-axis direction, and sending the first distance value and the second distance value to the numerical control system in real time;

[0031] S4. The numerical control system calculates a corrected cutting path using the predetermined cutting path and the measured first distance value and second distance value, and generates a cut in the plate by moving the laser cutting head along the corrected cutting path.

[0032] Specific:

[0033] In step S1, the plate is transported forward along the transmission direction X-axis through multiple groups of belt conveyors, and a light-transmitting slit is provided on the belt conveyor for passing the laser. N laser cutting heads are provided along the conveying direction of the plate, and the serial numbers change in the order of 1, 2, 3, ..., N, correspondingly setting the closed figure of the moving plate into N processing areas, which are the areas corresponding to the predetermined cutting trajectory processed by each laser cutting head. Each laser cutting head is individually controlled by a group of three-axis transmission mechanisms, which can drive the laser cutting head to move along the X-axis, Y-axis, and Z-axis directions, and the X-axis, Y-axis, and Z-axis are perpendicular to each other in three-dimensional space.

[0034] In step S2, the numerical control system controls the actual movement speed of the laser cutting head in the X-axis direction to be equal to the sum of the movement speed of the plate along the conveyor belt direction and the set speed of the laser cutting head in the X-axis direction when the plate is stationary, and the numerical control system controls the actual movement speed of the laser cutting head in the Y-axis direction to be equal to the set speed of the laser cutting head in the Y-axis direction when the plate is stationary.

[0035] In step S3, the first distance value and the second distance value are measured by a first distance measuring device arranged upstream of the laser cutting device and a second distance measuring device arranged downstream of the laser cutting device, respectively, and the measured values ​​are sent to the numerical control system in real time.

[0036] In step S4, the displacement compensation value of the laser cutting head in the Y direction and the rotation angle compensation value in the X direction are calculated according to the following formula (1):

[0037]

[0038] The first measuring point is set at a fixed position in the entrance area of ​​the first cutting processing area, and the small displacement a(t) at the first measuring point is measured in millimeters. In formula (1), a(t i )、a(t n ) are the initial sampling time t i time, at t i The sampling time after t n At the sampling value of time (where n ranges from j to infinity), the metal sheet strip moves from left to right to the processing area, and the first distance a(t i ) as the initial sampling time, and the initial sampling time t i The measured value a(t i ) as the reference value;

[0039] A second measuring point is set at a fixed position in the entrance area of ​​the second cutting processing area, and the small displacement b(t) at the second measuring point is measured in millimeters. In formula (1), b(t j )、b(t n ) are the initial sampling time t j time, at t j The sampling time after t n At the sampling value of time (where n is from j to infinity), the metal sheet strip moves from left to right to the processing area, and the second distance value b (t j ) as the initial sampling time, and the initial sampling time t j The measured value b(t j ) as the reference value;

[0040] In formula (1), m is the vertical distance between the first measuring point and the second measuring point along the X-axis direction, which is a constant value in millimeters. The first measuring point and the second measuring point are not necessarily on a straight line along the X-axis direction. k1 and k2 are respectively nAt the moment, the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction of the two areas is in millimeters, and α is the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction at the moment, and the unit is in millimeters. n At this moment, the laser cutting head processing set trajectory of the two areas is the rotation angle compensation value of the angle between the positive direction of the X axis.

[0041] During the first cutting, the machining coordinate system is manually calibrated to perform displacement compensation in the X and Y directions to close the cutting pattern. During the subsequent dynamic cycle cutting, the CNC system converts the displacement compensation value and the rotation angle compensation value into G code. The converted G code uses the displacement compensation value and the rotation angle compensation value to perform displacement compensation in the Y direction and rotation angle compensation on the machining coordinate system in the positive direction of the X axis. The converted G code performs real-time compensation on the rotation angle of the laser cutting head processing setting trajectory in the first cutting processing area and the second cutting processing area in the Y direction and the positive direction of the X axis.

[0042] Take two laser cutting heads for plate cutting and processing closed figures as an example. Two laser cutting devices are set up, which have two laser cutting heads that can move in the plate conveying direction (X direction), in the Y direction perpendicular to the plate conveying direction, and in the Z direction perpendicular to the plane formed by the X and Y directions; the two laser cutting heads are arranged in a front-to-back order in the conveying direction (X direction) to form two cutting processing areas (the first cutting processing area and the second cutting processing area); and there is also a numerical control system for controlling the two laser cutting heads to move along the cutting path corresponding to the predetermined contour, and two groups of belts convey the plate along the conveying direction (X direction). Each group of belts has a group of light slits. When the cutting head cuts the plate, it is located in the middle position of this group of light slits, so that when the cutting head cuts the plate, it will not damage the belt equipment itself. Laser measurement is widely used in non-contact measurement because of its advantages such as non-contact, high precision, fast measurement speed, stable and reliable performance. In order to solve the demand for high-speed real-time precision ranging in the laser blanking equipment industry, a laser displacement ranging sensor is used to measure the moving distance of the plate side in the Y-axis direction. The specific process is as follows:

[0043] 1. Assume that at time t, the first distance value from the first measuring point fixed at the entrance area of ​​the first cutting process to the edge of the first strip is a(t) mm, and the second distance value from the second measuring point fixed at the entrance area of ​​the second cutting process to the edge of the second strip is b(t) mm.

[0044] 2. The metal sheet strip moves from left to right to the processing area, and the first distance a(t i ) as the initial sampling time, and the initial sampling time t i The measured value a(t i) as the reference value. The metal sheet strip moves from left to right to the processing area, and the second distance value b (t j ) as the initial sampling time, and the initial sampling time t j The measured value b(t j ) as the reference value.

[0045] 3. In t i ,t j The sampling time after t n At the time (where n ranges from j to infinity), the first distance value from the first fixed measuring point in the entry area of ​​the cutting process to the first strip edge is a(t n ) mm, the second distance value from the second measuring point fixed in the entry area of ​​the second zone cutting process to the second strip edge is b(t n ) mm.

[0046] 4. The vertical distance between the first measuring point and the second measuring point along the X-axis is set to m, which is a fixed value in millimeters. The first measuring point and the second measuring point do not have to be in a straight line along the X-axis.

[0047] 5. Calculate the displacement compensation of the laser cutting head in the Y direction and the rotation angle compensation in the X direction according to the following formula (1):

[0048]

[0049] In the formula, k1 and k2 are respectively n At the moment, the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction of the two areas is in millimeters. α is the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction at the moment, in millimeters. n At this moment, the laser cutting head processing set trajectory of the two areas is the rotation angle compensation value of the angle between the positive direction of the X axis.

[0050] 6. During the first cutting, the machining coordinate system is manually calibrated to compensate for displacement in the X and Y directions to close the cutting pattern. During the subsequent dynamic cycle cutting, the CNC system converts the displacement compensation value and the rotation angle compensation value into G code. The converted G code uses the displacement compensation value and the rotation angle compensation value to compensate for the displacement in the Y direction and the rotation angle of the angle with the positive direction of the X axis of the machining coordinate system. The converted G code performs real-time compensation for the rotation angle of the laser cutting head machining setting trajectory in the first cutting processing area and the second cutting processing area in the Y direction and the angle with the positive direction of the X axis: the CNC system collects a(t n )、b(t n ) value. The control system uses the converted G code at t nAt this moment, the displacement compensation in the Y direction of the cutting path in zone 1 is k1 mm, and the rotation angle compensation in the X direction is α; the displacement compensation in the Y direction of the cutting path in zone 2 is k2 mm, and the rotation angle compensation in the X direction is α. In this case, a corrected cutting path represented by a dotted line is generated.

[0051] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control method for continuously cutting a metal sheet blank, characterized in that: The following steps are involved: S1. Arrange multiple laser cutting heads along the transmission direction of the plate, and divide the closed cutting track of the plate processing pattern into segmented cutting tracks of multiple processing areas; S2. Use a numerical control system to control the movement of the laser cutting head, that is, control the movement speed of the laser cutting head in the X-axis direction of the plate transmission direction, and control the movement speed of the laser cutting head in the Y-axis direction perpendicular to the X-axis; S3, continuously measuring a first distance value between a first strip edge of the plate and a first fixed measuring point in the Y-axis direction, and a second distance value between a second strip edge of the plate and a second fixed measuring point in the Y-axis direction, and sending the first distance value and the second distance value to the numerical control system in real time; S4. The numerical control system calculates a corrected cutting path using the predetermined cutting path and the measured first distance value and second distance value, and generates a cut in the plate by moving the laser cutting head along the corrected cutting path.

2. A control method for continuously cutting a metal sheet blank according to claim 1, characterized in that: In step S1, the plate is transported forward along the transport direction X-axis by multiple sets of belt conveyors.

3. A control method for continuously cutting a metal sheet blank according to claim 2, characterized in that: A light-transmitting slit is provided on the conveyor belt for the laser to pass through.

4. The control method for continuously cutting a metal sheet blank according to claim 1, characterized in that: Each laser cutting head is individually controlled by a set of three-axis transmission mechanisms, which can drive the laser cutting head to move along the X-axis, Y-axis, and Z-axis directions, and the X-axis, Y-axis, and Z-axis are perpendicular to each other in three-dimensional space.

5. The control method for continuously cutting a metal sheet blank according to claim 1, characterized in that: In step S2, the numerical control system controls the actual movement speed of the laser cutting head in the X-axis direction to be equal to the sum of the movement speed of the plate along the conveyor belt direction and the set speed of the laser cutting head in the X-axis direction when the plate is stationary, and the numerical control system controls the actual movement speed of the laser cutting head in the Y-axis direction to be equal to the set speed of the laser cutting head in the Y-axis direction when the plate is stationary.

6. A control method for continuously cutting a metal sheet blank according to claim 1, characterized in that: In step S3, the first distance value and the second distance value are measured by a first distance measuring device arranged upstream of the laser cutting device and a second distance measuring device arranged downstream of the laser cutting device, respectively, and the measured values ​​are sent to the numerical control system in real time.

7. A control method for continuously cutting a metal sheet blank according to claim 1, characterized in that: In step S4, the displacement compensation value of the laser cutting head in the Y direction and the rotation angle compensation value in the X direction are calculated according to the following formula (1): The first measuring point is set at a fixed position in the entrance area of ​​the first cutting processing area, and the small displacement a(t) at the first measuring point is measured in millimeters. In formula (1), a(t i )、a(t n ) are the initial sampling time t i time, at t i The sampling time after t n The sampling value at the time, where n ranges from j to infinity, the metal sheet strip moves from left to right to the processing area, and the first distance value a(t i ) as the initial sampling time, and the initial sampling time t i The measured value a(t i ) as the reference value; A second measuring point is set at a fixed position in the entrance area of ​​the second cutting processing area, and the small displacement b(t) at the second measuring point is measured in millimeters. In formula (1), b(t j )、b(t n ) are the initial sampling time t j time, at t j The sampling time after t n The sampling value at the time, the metal sheet strip moves from left to right to the processing area, and the second distance value b (t j ) as the initial sampling time, and the initial sampling time t j The measured value b(t j ) as the reference value; In formula (1), m is the vertical distance between the first measuring point and the second measuring point along the X-axis direction, which is a constant value in millimeters. The first measuring point and the second measuring point are not necessarily on a straight line along the X-axis direction. k1 and k2 are respectively n At the moment, the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction of the two areas is in millimeters, and α is the displacement compensation value of the laser cutting head processing setting trajectory in the Y direction at the moment, and the unit is in millimeters. n At this moment, the laser cutting head processing set trajectory of the two areas is the rotation angle compensation value of the angle between the positive direction of the X axis.

8. A control method for continuously cutting a metal sheet blank according to claim 7, characterized in that: During the first cutting, the machining coordinate system is manually calibrated to perform displacement compensation in the X and Y directions to close the cutting pattern. During the subsequent dynamic cycle cutting, the CNC system converts the displacement compensation value and the rotation angle compensation value into G code. The converted G code uses the displacement compensation value and the rotation angle compensation value to perform displacement compensation in the Y direction and rotation angle compensation on the machining coordinate system in the positive direction of the X axis. The converted G code performs real-time compensation on the rotation angle of the laser cutting head processing setting trajectory in the first cutting processing area and the second cutting processing area in the Y direction and the positive direction of the X axis.

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