A laser cutting control method for a bulletproof plate and its cutting machine

Abstract

The present invention discloses a laser cutting control method for a bulletproof plate and a cutting machine thereof, which specifically relates to the technical field of bulletproof plate cutting. It includes an equipment body, a laser head, detectors, a driving mechanism, and a controller. The detectors are multiple and are circumferentially and arrayedly distributed on the side of the laser head. The multiple detectors can form a detection area around the laser head and can detect the coordinates of the surfaces of multiple bulletproof plates on the cutting path. The controller can preset a fitting curve of the bulletproof plate curved surface according to the detected coordinates of the detectors; the controller can preset the cutting path of the laser head according to the fitting curve, and the controller can control the movement of the driving mechanism and the rotation of the laser head according to the cutting path. By calculating the fitting curve and presetting the cutting parameters, the present invention solves the problems that when the surface height at different positions of the curved surface changes, the laser focus cannot always fall on the material surface, and when the laser is vertically incident on the inclined curved surface, the energy density per unit area decreases.

Description

Technical Field

[0001] The present invention relates to the technical field of bulletproof plate cutting. More specifically, the present invention relates to a laser cutting control method for bulletproof plates and a cutting machine therefor. Background Art

[0002] A bulletproof plate is a key piece of equipment that achieves ballistic protection through material and structural design. It mainly uses high-performance materials such as ultra-high molecular weight polyethylene fibers and ceramic composite materials, combined with a "ceramic panel + fiber back panel" composite structure to resist the impact energy of projectiles while ensuring light weight. After the bulletproof plate is processed and formed, a laser cutting machine is generally used for cutting.

[0003] However, bulletproof plates are generally curved inserts designed according to ergonomics. When a laser cutting machine performs curved surface cutting, it may cause beam focusing problems because the laser head is usually designed for planar cutting and the laser focus position is fixed on the plane. When the surface height at different positions of the curved surface changes, the laser focus cannot always fall on the material surface, and the incision depth fluctuates, which may result in non-compliance with the local strength requirements of the bulletproof insert.

[0004] Chinese Patent with Application No. 202410235219.3 discloses a laser cutting machine for steel. This invention solves the problem that traditional laser cutting machines can only cut steel at a fixed angle and have a narrow scope of application by setting lifting mechanisms at the four corners of the material stabilizer to endow the steel placed on the material stabilizer with the function of adjusting the angle. However, when cutting bulletproof plates, the cutting path usually needs to match the size of the bulletproof plate, and usually multiple bulletproof plates can be cut from one piece of material. Therefore, it is necessary to adjust the angle multiple times for cutting, and the method of changing the cutting angle by adjusting the material stabilizer is relatively inconvenient.

[0005] At the same time, when the laser beam has a certain angle with the irradiated surface, the light spot will become elliptical, the actual acting area increases, and the energy density per unit area decreases, which may cause the material not to be cut through. In the steep area of the curved surface, heat may be concentrated due to multiple reflections, resulting in material burning or performance degradation. Therefore, the present invention proposes a laser cutting control method for bulletproof plates and a cutting machine therefor to solve the above problems. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a laser cutting control method for bulletproof plates and a cutting machine therefor to solve the problems raised in the above background art.

[0007] To achieve the above object, the present invention provides the following technical solution: A control method for laser cutting of bulletproof plates, comprising the following steps:

[0008] S1. Periodically measure the coordinates of multiple points on the surface of the bulletproof plate, analyze the coordinates of the multiple points, and screen at least three key coordinates;

[0009] S2. According to the key coordinates, calculate the center and radius of the arc that fits the local surface of the bulletproof plate, and calculate the fitting curve based on the center and radius;

[0010] S3. Calculate the coordinates and incident direction of the laser head when it is at the point to be cut according to the fitting curve;

[0011] S4. Take the coordinates and incident directions of multiple points to be cut as preset parameters, generate a parameter mapping table according to the preset parameters, and preset the cutting path according to the parameter mapping table;

[0012] S5. Control the laser head to be positioned according to the cutting path and cut the bulletproof plate.

[0013] Preferably, divide the curved surface of the bulletproof plate into multiple independent curved surface segments, calculate the local surface parameters for each segment independently, and generate the fitting curve.

[0014] Preferably, in step S1, periodically measure the coordinates of at least three points on the surface of the bulletproof plate, and the coordinates of the multiple points are coplanar with the coordinates of the points to be cut.

[0015] Preferably, the incident direction of the laser head is perpendicular to the tangent of the fitting curve at the point to be cut.

[0016] Preferably, calculate the initial coordinates of the starting point of the cutting path according to the initial distance from the laser head to the bulletproof plate and the radius of the fitting curve.

[0017] Preferably, calculate the deflection angle of the laser head according to the initial coordinates of the starting point of the cutting path and the incident direction.

[0018] Preferably, preset the cutting path according to the deflection angle of the laser head and the initial distance from the laser head to the curved surface.

[0019] The present application also provides a cutting machine, which adopts the above control method for laser cutting of bulletproof plates, and includes: a device body, a laser head, a detector, a driving mechanism, and a controller; the laser head is arranged inside the device body, and the laser head is in transmission connection with the driving mechanism for laser cutting of the bulletproof plate; there are multiple detectors, which are circumferentially and arrayed on the side of the laser head, and the multiple detectors can form a detection area around the laser head to detect the coordinates of multiple points on the surface of the bulletproof plate; the controller is electrically connected to the detector, and the controller is used to calculate the fitting curve of the bulletproof plate surface according to the coordinates of multiple points detected by the detector, and preset the cutting path of the laser head according to the fitting curve, and then control the driving mechanism to drive the laser head to move or rotate according to the cutting path to cut the bulletproof plate.

[0020] Preferably, one end of the laser head is fixedly connected with a fixing plate, the end of the fixing plate away from the laser head is fixedly connected with an electric push rod, the electric push rod is electrically connected to the controller, and multiple detectors are fixedly connected to the fixing plate.

[0021] Preferably, the controller is electrically connected to the driving mechanism, the controller can remotely control the driving mechanism to drive the laser head for positioning, a motor is fixedly connected to the side of the electric push rod, one end of the motor is fixedly connected with a mounting plate, the mounting plate is in transmission connection with the driving mechanism, and the motor is electrically connected to the controller.

[0022] The technical effects and advantages of the present invention:

[0023] 1. According to the present invention, the controller controls the electric push rod according to the fitting curve and the initial distance D, so that the height of the laser head follows the change of the radian of the fitting curve during the cutting process, so as to ensure that the focus of the laser head is always on the surface of the bulletproof plate, thereby preventing the problem that when the surface height at different positions of the curved surface changes, the laser focus cannot always fall on the material surface, and the cutting depth fluctuates, resulting in the local strength of the bulletproof insert not meeting the standard.

[0024] 2. According to the present invention, by making the incident direction of the laser perpendicular to the tangent direction of the fitting curve at the cutting point, it is possible to prevent the problem that when the laser is vertically incident on an inclined curved surface, the light spot will become elliptical, the energy density per unit area will decrease, and the steep area of the curved surface may accumulate heat due to multiple reflections, resulting in material burning or performance degradation.

[0025] 3. According to the present invention, by presetting the cutting parameters and refreshing the fitting curve data in real time, it is possible to prevent the problems of data delay when the laser head performs cutting and inaccurate incident angles and distances caused by different curved surface degrees at different positions of the bulletproof plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 This is a schematic diagram of the structure of the laser head of the present invention.

[0028] Figure 3 It is a schematic diagram of the coordinates of the curved surface detected by the detector of the present invention.

[0029] Figure 4 This is a schematic diagram of the fitting curve calculated by the controller of the present invention.

[0030] Figure 5 Schematic diagram of incident direction calculation for the controller of the present invention.

[0031] Figure 6 The figure is a flow chart of the control method of the controller of the present invention.

[0032] The accompanying drawings are marked as follows: 1. Equipment body; 2. Laser head; 21. Fixing plate; 22. Electric push rod; 23. Motor; 3. Detector; 4. Driving mechanism; 5. Controller. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] In the actual production process, due to the change in surface height at different positions of the curved surface, the laser focus cannot always fall on the material surface, and the incision depth fluctuates, which will cause the local strength of the bulletproof insert to fail to meet the standard. This embodiment is specially invented to solve the above problem.

[0036] See also Figures 1 to 6 As shown, a control method for laser cutting of a bulletproof plate according to an embodiment of the present invention, the control method relates to a cutting machine, comprising: an equipment body 1, a laser head 2, a detector 3, a driving mechanism 4 and a controller 5; the laser head 2 is arranged inside the equipment body 1, and the laser head 2 is connected to the driving mechanism 4 for laser cutting of the bulletproof plate; the detectors 3 are multiple and circumferentially arrayed on the side of the laser head 2, and the multiple detectors 3 can form a detection area around the laser head 2 to detect the coordinates of multiple points on the surface of the bulletproof plate; the controller 5 is electrically connected to the detector 3, and the controller 5 is used to calculate the fitting curve of the surface of the bulletproof plate according to the coordinates of the multiple points detected by the detector 3, and preset the cutting path of the laser head 2 according to the fitting curve, and then control the driving mechanism 4 to drive the laser head 2 to move or rotate according to the cutting path to cut the bulletproof plate.

[0037] Please refer to Figure 2 As shown, one end of the laser head 2 is fixedly connected with a fixing plate 21. The end of the fixing plate 21 away from the laser head 2 is fixedly connected with an electric push rod 22. The electric push rod 22 is electrically connected with the controller 5 in an electrical signal manner. A plurality of detectors 3 are all fixedly connected with the fixing plate 21.

[0038] Please refer to Figure 1 and Figure 2 As shown, the controller 5 is electrically connected with the driving mechanism 4 in an electrical signal manner. The controller 5 can remotely control the driving mechanism 4 to drive the laser head 2 for positioning. A motor 23 is fixedly connected to the side of the electric push rod 22. One end of the motor 23 is fixedly connected with a mounting plate. The mounting plate is in transmission connection with the driving mechanism 4. The motor 23 is electrically connected with the controller 5 in an electrical signal manner.

[0039] Please refer to Figure 3 and Figure 4 As shown, the control method for laser cutting includes the following steps:

[0040] S1. Periodically measure the coordinates of multiple points on the surface of the bulletproof plate, analyze the coordinates of the multiple points, and screen at least three key coordinates;

[0041] S2. According to the key coordinates, calculate the center and radius of the arc that fits the local surface of the bulletproof plate, and calculate the fitting curve based on the center and radius;

[0042] S3. Calculate the coordinates and incident direction of the laser head when it is at the point to be cut according to the fitting curve;

[0043] S4. Take the coordinates and incident direction of multiple points to be cut as preset parameters, generate a parameter mapping table according to the preset parameters, and preset the cutting path according to the parameter mapping table;

[0044] S5. Control the laser head to be positioned and cut the bulletproof plate according to the cutting path.

[0045] Please refer to Figure 3 and Figure 4 As shown, the curved surface of the bulletproof plate is divided into multiple independent curved surface segments, and the local curved surface parameters are calculated independently for each segment to generate a fitting curve.

[0046] Please refer to Figure 3 and Figure 4 As shown, in step S1, the coordinates of at least three points on the surface of the bulletproof plate are measured periodically, and the coordinates of the multiple points are coplanar with the coordinates of the points to be cut.

[0047] Please refer to Figure 5As shown, the incident direction of the laser head 2 is perpendicular to the tangent of the fitting curve at the point to be cut. The controller 5 calculates the initial coordinates of the starting point of the cutting path based on the initial distance from the laser head 2 to the bulletproof plate and the radius of the fitting curve, and calculates the deflection angle of the laser head 2 based on the initial coordinates of the starting point of the cutting path and the incident direction.

[0048] Please refer to Figure 5 As shown, the controller 5 presets the cutting path according to the deflection angle of the laser head 2 and the initial distance from the laser head 2 to the curved surface.

[0049] During use, the operator controls the drive mechanism 4 through the controller 5 to move the laser head 2 to the processing area, and controls the electric push rod 22 through the controller 5 to drive the laser head 2 to move so that the focus falls on the surface of the bulletproof plate. At this time, the controller 5 records the initial distance D between the laser head 2 and the bulletproof plate. During cutting, the detector 3 detects the surface coordinates of the bulletproof plate. When the detector 3 detects the surface coordinates of the bulletproof plate, the controller 5 calculates the center and radius of the curved surface of the bulletproof plate according to the detection parameters of the detector 3. For example, if the detector 3 detects three coordinates P1(x1, y1), P2(x2, y2), and P3(x3, y3) respectively, then through the following formula

[0050] ,

[0051] ,

[0052] , the coordinates of the center O(h, k) can be calculated. When the controller 5 calculates the coordinates of the center of the curved surface, the radius R of the curved surface can be calculated according to any detected coordinate. The curve fitting the curved surface can be obtained through the center O and the radius R. The controller 5 controls the electric push rod 22 according to the fitting curve and the initial distance D, so that the height of the laser head 2 follows the change of the arc of the fitting curve during the cutting process, so as to ensure that the focus of the laser head 2 is always on the surface of the bulletproof plate, thus preventing the problem that when the surface height at different positions of the curved surface changes, the laser focus cannot always fall on the surface of the material, the cutting depth fluctuates, and the local strength of the bulletproof insert does not meet the standard.

[0053] Embodiment 2

[0054] It is found in actual use that when the laser is vertically incident on an inclined curved surface, the light spot will become elliptical, the actual acting area increases, and the energy density per unit area decreases, which may cause incomplete cutting. In the steep area of the curved surface, heat may be concentrated due to multiple reflections, resulting in material burning or performance degradation. Further improvements are made on the basis of the above embodiments.

[0055] Based on the above embodiments, during use, the controller 5 calculates the coordinates of the point to be cut according to the fitting curve, and calculates the incident direction at the coordinates of the point to be cut according to the center O and radius R of the fitting curve. For example, when the coordinates of the point to be cut are P1(x1, y1), the angle between the incident direction when the laser head 2 is at P1 and the initial incident direction can be calculated, that is, the angle θ by which the laser head 2 needs to deflect:

[0056]

[0057] As Figure 5 shown, after the controller 5 calculates the deflection angle θ, it calculates the cutting path of the laser head 2 according to the deflection angle θ and the initial distance D. The controller 5 controls the rotation of the motor 23 and the movement of the electric push rod 22 according to the cutting path, so that the laser head 2 changes the incident direction and incident distance of the laser according to the radian of the fitting curve during cutting, so that the incident direction of the laser is perpendicular to the tangent direction of the fitting curve at the cutting point, preventing the problem that when the laser is vertically incident on the inclined surface, the light spot will become oval, the energy density per unit area will decrease, and the steep area of the surface may accumulate heat due to multiple reflections, resulting in material burn or performance degradation.

[0058] Embodiment 3

[0059] During actual use, it is found that since the detector 3 and the controller 5 perform calculations while the cutting is in progress, it is easy to cause data delay when the laser head 2 performs cutting, and the surface degrees of different positions of the bulletproof plate are different, which will cause the actual incident angle and distance of the laser during cutting to be inaccurate. Further improvements are made based on the above embodiments.

[0060] During use, multiple detectors 3 divide the curved surface of the bulletproof plate into several segments. Each segment independently calculates the local surface parameters and presets the fitting curve through the controller 5. At the same time, during the movement of the laser head 2, the detectors 3 move synchronously and continuously detect new coordinates to provide to the controller 5 for calculating the fitting curve, so as to ensure that during the cutting process, the data of the fitting curve is continuously detected and refreshed. The controller 5 uses the coordinates and incident directions of multiple points to be cut in the fitting curve as preset parameters. The controller 5 uses each point coordinate to be cut and its corresponding deflection angle in the preset parameters as mapping parameters, and generates a mapping parameter table according to the coordinate-angle mapping principle (the coordinate-angle mapping principle is to unify the spatial position and rotation posture into executable processing parameters through geometric modeling and kinematic algorithms) based on multiple mapping parameters, and presets the cutting path according to the mapping parameter table, so as to ensure that before the laser head 2 moves to the point to be cut, the controller 5 has calculated the parameters of the point to be cut, and prevent the data delay when the laser head 2 performs cutting and the problem of inaccurate incident angle and distance caused by different surface degrees of different positions of the bulletproof plate through preset cutting parameters and real-time refreshing of the fitting curve data.

[0061] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A control method for laser cutting of bulletproof plates, characterized in that, The following steps are involved: S1, periodically measuring the coordinates of multiple points on the surface of the bulletproof plate, analyzing the coordinates of the multiple points and selecting at least three key coordinates; S2. Calculate the center and radius of the arc that fits the local surface of the bulletproof plate according to the key coordinates, and calculate the fitting curve according to the center and radius; S3, calculating the coordinates and incident direction of the laser head when it is located at the point to be cut according to the fitting curve; S4, taking the coordinates of the multiple points to be cut and the incident direction as preset parameters, generating a parameter mapping table according to the preset parameters and presetting the cutting path according to the parameter mapping table; S5, controlling the laser head to position and cut the bulletproof plate according to the cutting path; In step S1, the coordinates of at least three points on the surface of the bulletproof plate are periodically measured, and the coordinates of the multiple points are coplanar with the coordinates of the points to be cut; The incident direction of the laser head is perpendicular to the tangent line of the fitting curve at the point to be cut; According to the fitting curve and the initial distance from the laser head to the bulletproof plate, the laser head is made to follow the arc change of the fitting curve during the cutting process; The initial coordinates of the starting point of the cutting path are calculated according to the initial distance from the laser head to the bulletproof plate and the radius of the fitting curve.

2. The control method according to claim 1, characterized in that The curved surface of the bulletproof plate is divided into a plurality of independent curved surface segments, and local curved surface parameters are calculated independently for each segment to generate the fitting curve.

3. The control method according to claim 2, characterized in that: The deflection angle of the laser head is calculated according to the initial coordinates of the starting point of the cutting path and the incident direction.

4. The control method according to claim 3, characterized in that: The cutting path is preset according to the deflection angle of the laser head and the initial distance from the laser head to the curved surface.

5. A bulletproof plate laser cutting machine, adopting the control method according to any one of claims 1-4, characterized in that, It includes the equipment body, laser head, detector, driving mechanism and controller; The laser head is arranged inside the equipment body, and the laser head is transmission-connected with the driving mechanism for laser cutting the bulletproof plate; The detectors are multiple and circumferentially arrayed on the side of the laser head, and the multiple detectors can form a detection area around the laser head to detect the coordinates of multiple points on the surface of the bulletproof plate; The controller is connected to the detector by electrical signals. The controller is used to calculate the fitting curve of the bulletproof plate surface according to the coordinates of multiple points detected by the detector, and preset the cutting path of the laser head according to the fitting curve, and then control the driving mechanism to drive the laser head to move or rotate according to the cutting path to cut the bulletproof plate.

6. The bulletproof plate laser cutting machine according to claim 5, characterized in that: One end of the laser head is fixedly connected to a fixing plate, and one end of the fixing plate away from the laser head is fixedly connected to an electric push rod, the electric push rod is connected to the controller by electrical signals, and the plurality of detectors are fixedly connected to the fixing plate.

7. The bulletproof plate laser cutting machine according to claim 6, wherein: The controller is connected to the driving mechanism by electrical signals. The controller can remotely control the driving mechanism to drive the laser head for positioning. A motor is fixedly connected to the side of the electric push rod. One end of the motor is fixedly connected to a mounting plate. The mounting plate is transmission-connected to the driving mechanism. The motor is connected to the controller by electrical signals.

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