JP2011235291A - Laser cutting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a connection connecting with a material to be cut in a part of a path corresponding to a target figure.SOLUTION: When a laser cutting nozzle is moved relative to a material to be cut 1 in a path 3 corresponding to a target figure 2 at a cutting speed, an average laser output, an assist gas pressure and a laser beam focus position suitable to cut the material 1, the capability of cutting the material is reduced in a local section to form a connection connecting the target figure to the material under a selected condition that the cutting speed is increased above the cutting speed suitable to cut the material, that the average laser output is reduced below the average laser output suitable to cut the material, that the assist gas pressure is reduced below the assist gas pressure suitable to cut the material, or that the laser beam focus position is moved inward of the focus position suitable to cut the material with respect to the thickness of the material.

Description

  The present invention connects a target figure and a material to be cut when irradiating a laser beam from a laser cutting nozzle toward the material to be cut and also injecting an assist gas to cut the target figure from the material to be cut. The present invention relates to a laser cutting method capable of forming a connecting portion.

  A laser cutting method may be employed when cutting a metal workpiece. In this laser cutting method, a laser beam is irradiated from a laser cutting nozzle toward a material to be cut, an assist gas is injected to evaporate or melt the base material, and the generated melt is excluded from the base material. The cutting nozzle is moved along a path corresponding to the target figure to form a continuous groove and cut.

  When laser cutting is performed on a material to be cut, the material to be cut is placed on a cutting surface plate, and then a through-hole in the thickness direction is formed (piercing) on the material to be cut to make a cutting start point, and laser In general, the target figure is separated from the material to be cut by moving the cutting nozzle along a path corresponding to the target figure. When such cutting is performed, the product cut into a shape corresponding to the target figure and the remaining material from which the product is cut are present on the cutting platen independently of each other. Become. For this reason, after the cutting operation is completed, it is necessary to individually perform the operation of discharging the remaining material from the cutting surface plate and the operation of discharging the product from the cutting surface plate. If the remaining material and the product are discharged separately from the cutting platen in this way, the work becomes complicated and there is a risk that the working time on the cutting platen will become short.

  For this reason, as shown in FIG. 7, when the target graphic 52 is cut from the material to be cut 51, a connection portion 53 that connects the two may be provided. In this case, after the cutting of the material to be cut is completed, the target graphic 52 can be discharged at the same time as the material 51 to be cut is discharged from the cutting surface plate, and the discharge work can be shortened.

  The above cutting will be briefly described. As shown in FIG. 7A, after piercing is performed at a position 55 off the path 54 corresponding to the target graphic 52 in the workpiece 51, the laser cutting nozzle is moved along the path 54 in the direction of the arrow. Move and cut. Then, when cutting to a preset interruption point 53 a of the connecting portion 53 on the path 54, the laser cutting nozzle is detached from the path 54 and the cutting is stopped at the point 56. Thereafter, piercing is performed at a point 57 separated from the path 54 to resume cutting, and the laser cutting nozzle is moved along the remaining path 54 from the resuming point 53b on the path 54, so that the product as the target graphic 52 is obtained. Disconnect.

  By performing laser cutting as described above, as shown in FIG. 7B, the product 52 and the material to be cut 51 have a length L and a plate thickness T from the cutting interruption point 53a to the resumption point 53b. It will be connected by the connection part 53 with the area which has a dimension equivalent to. For this reason, when discharging from the cutting surface plate, the material to be cut 51 and the product 52 can be handled as one material (the material to be cut 51). Therefore, the work of discharging the material to be cut 51 and the product 52 after cutting becomes extremely easy, and along with this, the time until the start of the work of bringing a new material to be cut onto the cutting surface plate can be shortened. It becomes possible.

  Then, the material to be cut 51 having the connection portion 53 between the product 52 discharged from the cutting surface plate is sent to the subsequent process, and the work for separating the product 52 from the material to be cut 51 is performed. This separation operation is generally performed by an operator giving an impact around the connection portion 53 using a plastic hammer or the like.

  As described above, when the product 52 and the material to be cut 51 are cut in a connected state, the connection portion 53 has an area formed by the product of the dimension L and the plate thickness T from the interruption point 53a to the resumption point 53b. For this reason, when the plate thickness is increased, there is a problem that it becomes difficult to separate the material to be cut from the product even if an impact is applied due to an increase in the area of the connecting portion.

  In order to solve the above problem, it is effective to reduce the dimension L from the interruption point to the resumption point at the connection portion. However, if this dimension is reduced, the heat applied at the interruption point or the resumption point is reduced. Under the influence of the applied heat, the base material constituting the connecting portion is melted, resulting in a problem that the strength sufficient to keep the product connected to the material to be cut cannot be exhibited.

  Further, since the cutting is resumed by piercing after the cutting is interrupted, there arises a problem that the working time required for the cutting is shortened. Furthermore, since the position where the cutting is stopped and the piercing position are set on the remaining material side, that is, on the remaining material side, it is possible to cut the remaining material after cutting the product. As a result, the area is reduced and the yield of the material is reduced.

  An object of the present invention is to perform laser cutting on a material to be cut while reducing a cutting ability of a part of a path corresponding to a target figure, while continuously moving a laser cutting nozzle along the path. Another object of the present invention is to provide a laser cutting method capable of forming a connection portion for connecting a target graphic and a material to be cut in a part of the path.

  The laser cutting method according to the present invention performs laser cutting at a cutting speed, laser average output, assist gas pressure, and laser beam focal position suitable for cutting the material to be cut from the laser cutting nozzle. When cutting by moving the nozzle along the path corresponding to the target graphic, the cutting speed is set to the cutting speed in a part of the process in which the laser cutting nozzle is moved along the path corresponding to the target graphic. Conditions for increasing the cutting speed suitable for cutting the material to be cut, conditions for reducing the average output of the laser to be lower than the average power for laser suitable for cutting the material to be cut, and assist gas pressure Conditions for lowering the assist gas pressure suitable for cutting the cutting material, and moving the focal position of the laser beam to the inner direction of the thickness of the cutting material from the focal position suitable for cutting the material to be cut Condition By selecting one condition or a plurality of conditions from the above conditions and reducing the cutting ability with respect to the material to be cut, a connection part for connecting the material to be cut and the target figure is formed. is there.

  In the laser cutting method, the material to be cut is obtained by reducing the cutting ability for the material to be cut in a part of the process in which the laser cutting nozzle is moved along a path corresponding to the target figure. After forming the connection part that connects the target figure and the target figure, the laser cutting nozzle is returned to the cutting speed, laser average output, assist gas pressure, and laser beam focus position suitable for cutting the workpiece. It is preferable to move and cut along a path corresponding to the target figure.

  In the laser cutting method according to the present invention, a connection portion that connects the material to be cut and the target graphic is formed in a path corresponding to the target graphic from the material to be cut without interrupting the cutting operation on the material to be cut. can do. In other words, in a part of the process of moving the laser cutting nozzle, the thickness is cut from the surface side of the material to be cut by cutting with a cutting ability lower than the cutting ability suitable for cutting the material to be cut. A kerf that does not penetrate in the direction can be formed. A connection part can be formed on the back side of the material to be cut by the cut groove.

  The depth of the kerf can be changed according to the degree to which the cutting ability is reduced. That is, one or more conditions selected from the cutting speed, the average laser output, the assist gas pressure, and the focal position of the laser light, which are conditions for determining the cutting ability, are set so as to reduce the cutting ability. Thus, the depth of the kerf can be adjusted, whereby the area of the connection portion between the target graphic and the material to be cut in the connection portion can be adjusted.

  Therefore, when the material to be cut that has been subjected to laser cutting is discharged from the cutting surface plate, the discharge work can be performed easily and in a short time with the material to be cut and the target graphic connected. Further, when separating the material to be cut and the target graphic in a subsequent process, they can be easily separated by applying an appropriate impact to the connecting portion.

  Furthermore, after cutting the cutting ability in a part of the path corresponding to the target figure to form a connection part, the cutting ability is restored to the cutting ability suitable for cutting the material to be cut, and laser cutting is performed. The nozzle can be continuously cut without deviating from the path of the target graphic. For this reason, it is not necessary to perform piercing other than the first piercing on the material to be cut, and cutting work can be performed without wasting time.

  In particular, since piercing other than piercing at the start of cutting is not performed, the material to be cut has a continuous portion of the initial piercing and a portion where the cutting is finished continuous with the path corresponding to the target figure. Although kerfs are formed, no extra kerfs are formed at other sites. Therefore, the area that can be cut in the remaining material after cutting the target graphic can be increased, and the material yield can be improved.

It is a figure which illustrates typically the composition for cutting a material to be cut. It is a figure explaining the example of the connection part which connects between a to-be-cut material and the target figure. It is a figure explaining the shape of a connection part when cutting speed is reduced rather than appropriate speed. It is a figure explaining the shape of a connection part when cutting speed is reduced rather than appropriate speed. It is a figure explaining the shape of a connection part when average output conditions are reduced from appropriate output. It is a figure explaining the shape of a connection part when average output conditions are reduced from appropriate output. It is a figure explaining the example of the connection part which connects between the to-be-cut material and the target figure conventionally performed.

  Hereinafter, the laser cutting method according to the present invention will be described. As shown in FIG. 1, the laser cutting method according to the present invention is referred to as a path (hereinafter referred to as “scheduled cutting line” or “grooving”) corresponding to a target figure (also referred to as “product”) 2 from a material 1 to be cut. ) When laser cutting 3, a connecting portion 4 for connecting the material 1 to be cut and the target graphic 2 is provided at a part of the planned cutting line 3. And by providing this connection part 4, after cutting | disconnection is complete | finished, while performing the operation | work at the time of discharging | emitting the to-be-cut material 1 from a cutting surface plate, the product 2 cut | disconnected from the discharged to-be-cut | disconnected material 1 Can be easily separated.

  In the present invention, the shape of the connecting portion 4 that connects the workpiece 1 and the target graphic 2 is not limited. However, the laser cutting method according to the present invention cuts more than the cutting conditions (appropriate cutting conditions) suitable for cutting the workpiece 1 in part while continuously cutting along the planned cutting line 3. Since the connection part 4 is formed by cutting under conditions with reduced capability (capacity reduction condition), a continuous kerf 3 is formed on the upper surface side of the material 1 to be cut. It is formed on the back side of the cutting material 1.

  Further, the area of the connecting portion 4 is not limited, and when the workpiece 1 after cutting the target graphic 2 is removed from the cutting surface plate, it is easily broken when the weight of the graphic 2 is applied. It is preferable that the area is such that it can be easily separated when an impact is applied when the target figure 2 is separated from the material 1 to be cut into a product.

  However, since it is not preferable to apply a large impact when separating the workpiece 1 and the product 2, when the weight of the product 2 is increased, two or more locations on the planned cutting line 3. It is preferable to form the connection part 4. In other words, in the present invention, the number of connecting portions 4 formed on the planned cutting line 3 is not limited, and is appropriately determined according to conditions such as the area of the target graphic 2 and the thickness of the material 1 to be cut. It is preferable to form the connecting portion 4.

  The connection portion 4 that connects the workpiece 1 and the target graphic 2 is formed in a state in which the planned cutting line 3 corresponding to the graphic 2 is not interrupted. That is, a continuous kerf 3 that does not penetrate the back surface in the thickness direction from the upper surface side of the material 1 to be cut is formed. As a result, the non-penetration of the kerf 3 is formed on the back surface side of the material 1 to be cut. Depending on the height h of the portion (the thickness of the material 1 to be cut in the non-cut portion) and the length L (the length along the planned cutting line 3 in the non-cut portion) of the non-penetrated portion A connecting portion 4 having a large area is formed.

  The length L in the connection part 4 is the length of a section in which the cutting ability is reduced when the connection part 4 is formed on the material 1 to be cut, and is set according to the time during which the cutting ability is reduced. . To shorten the time during which the cutting ability is reduced is to shorten the length of the connecting portion 4, and the base material that should form the connecting portion 4 may be melted by the heat generated during cutting. Arise. Further, to increase the time for reducing the cutting ability is to increase the length of the connecting portion 4, and if it is too long, it may be difficult to separate the product 2 from the workpiece 1. Arise.

  The height h at the connection portion 4 is set according to the degree of reduction when the cutting ability is reduced when the connection portion 4 is formed on the workpiece 1. That is, if the degree of lowering the cutting ability is small, the dimension of the height h is increased, and there is a risk that the work of separating the product 2 from the material to be cut 1 may be difficult. There is a possibility that the dimension of the height h becomes small and the function as the connection portion 4 cannot be exhibited.

  In the present invention, the condition for reducing the ability when forming the connecting portion 4 is a condition (speed condition) for increasing the cutting speed to a cutting speed suitable for cutting the material 1 to be cut, and the average output of the laser. For lowering the average output of the laser suitable for cutting the workpiece 1 (average output condition), and for reducing the assist gas pressure lower than the assist gas pressure suitable for cutting the workpiece 1 (Assist gas condition) is a condition (focus condition) in which the focal position of the laser beam is moved inward of the thickness of the material to be cut from the focus position suitable for cutting the material 1 to be cut. And it is possible to form the connection part 4 in a part of the scheduled cutting line 3 by selecting one of these conditions or selecting and combining a plurality of conditions.

  When the speed condition is selected when forming the connection part 4, the degree to which the cutting speed (appropriate speed) suitable for cutting the workpiece 1 is increased is not limited, and the connection part to be formed It is preferable to set according to the area and shape of 4. In particular, when changing the cutting speed, it takes time (rise time, fall time) to shift from the current speed to the speed to be changed. Therefore, the shape of the connecting portion 4 is such that the back surface of the workpiece 1 is the bottom. It becomes a triangle or trapezoid.

  Further, when the average output condition is selected, there is no limitation on how much the average output suitable for cutting (appropriate average output) is reduced. Since the time required to change the output of the laser oscillator is extremely short, and the average output is changed instantaneously, the shape of the connecting portion 4 is substantially rectangular.

  Moreover, when assist gas conditions are selected, it is not limited to how much the assist gas pressure (appropriate pressure) suitable for cutting is reduced. When changing the assist gas, since there is a distance from the assist gas supply device to the laser cutting nozzle, it takes time until the pressure actually changes after a command to change the pressure of the assist gas is issued. For this reason, the shape of the connection part 4 becomes a substantially triangle.

  In addition, when the focus condition is selected, there is no limitation on how to change the focus suitable for cutting (appropriate focus). The focal position is changed by moving the laser cutting nozzle up and down or moving the lens up and down with a motor, and the focal position changes while laser light is emitted from the laser oscillator. For this reason, inclined portions are formed on the start point 4a side and the end point 4b side of the connecting portion 4, and the overall shape is trapezoidal.

  The apparatus configuration for moving the laser cutting nozzle when laser cutting the target figure 2 on the workpiece 1 is not limited. As a cutting apparatus for laser cutting the workpiece 1, there are a cutting robot and an apparatus configured to move along the same route while tracing a drawing.

  In this embodiment, as schematically shown in FIG. 1, a gate-type frame 15 that is movably mounted on a pair of rails 12 laid across a cutting surface plate 11, and is mounted on the frame 15. The traverse carriage 16 traversing in a direction perpendicular to the laying direction of the rail 12, the laser cutting nozzle 17 mounted on the traverse carriage 16, the laser oscillator 18 connected to the laser cutting nozzle 17, the traveling of the frame 15, and A laser cutting device 20 having a control panel 19 incorporating a numerical control (NC) device that performs a series of controls necessary for cutting including the traverse of the traverse carriage 16 and the operation of the laser oscillator 18 is used.

  An assist gas supply device (not shown) is connected to the laser cutting nozzle 17. The assist gas supply device includes an oxygen gas supply source such as a cylinder or a pipe in a factory, and a pressure regulator that adjusts the pressure of the supplied oxygen gas to an appropriate pressure or a pressure lower than the appropriate pressure. , And is configured.

  The laser cutting nozzle 17 incorporates a lens (not shown) that collects the laser beam. This lens is fixed to the laser cutting nozzle 17 or configured to move along the optical axis of the laser light within the laser cutting nozzle 17. For this reason, the focal point position with respect to the to-be-cut | disconnected material 1 is made into an appropriate focus, or cutting capability by making the lens incorporated in the laser cutting nozzle 17 and the laser-cutting nozzle 17 approach or separate from the surface of the to-be-cut | disconnected material 1. It is possible to adjust to the lowered position.

  Information on the figure 2 to be cut from the preset workpiece 1 is input to the NC device built in the control panel 19 and the formation position of the connection portion 4 in the figure 2 is input. Further, the NC device includes a speed condition composed of a combined speed of the frame 15 and a transverse speed of the transverse carriage 16, an average output condition composed of an average output of the laser oscillator 18, an assist gas condition composed of an assist gas pressure, a laser. An appropriate cutting condition with respect to a focus condition composed of the focal position of light and an ability reduction condition for reducing the ability of one or more conditions selected from the above conditions are input.

  Then, the workpiece 1 is placed on the cutting platen 11 and the laser cutting device 20 is operated to cut the figure 2 from the workpiece 1. At this time, according to the information on the planned cutting line 3 for cutting the figure 2 with respect to the workpiece 1 and the information on the connection part 4 and the appropriate condition and the ability reduction condition according to the information for cutting the figure 2 Then, the assist gas supply device connected to the frame 15, the transverse carriage 16, the laser oscillator 18, and the laser cutting nozzle 17 is controlled, and the figure 2 in which the connecting portion 4 is formed between the workpiece 1 and the cutting object 1 is cut. .

  After the connection part 4 is formed between the workpiece 1 and the figure 2 as described above and the cutting is completed, the workpiece 1 is conveyed from the cutting surface plate 11 to a separation yard (not shown). When the workpiece 1 is transported, when the hook is hooked on both sides in the width direction and lifted by the crane, the figure 2 is lifted together with the workpiece 1 so that the workpiece 1 and the figure 2 are cut in one operation. It becomes possible to discharge from the surface plate 11.

  The present inventors changed the speed condition, the average output condition, the assist gas condition, and the focus condition described above when forming the connection part 4 between the workpiece 1 and the figure 2, and formed the connection part. An experiment to determine 4 was conducted.

  This experiment was performed with materials: SS400, plate thickness: 6 mm, 12 mm, 16 mm, 19 mm, 22 mm, laser oscillator; carbon dioxide laser with a peak output of 4000 W, assist gas; oxygen gas. In addition, an appropriate cutting speed and an appropriate assist gas pressure change corresponding to the plate thickness.

  The speed condition was changed so as to increase every 50% within the range of 150% to 350% from the appropriate speed. The average output condition was changed so that the duty ratio was decreased every 10% in the range of 10% to 30%. Moreover, the pressure conditions were changed so as to decrease from 10% to 30% from the appropriate pressure every 10%. Further, the focal condition was changed so as to enter the inside every 2 mm within a range of 2 mm to 6 mm from the surface of the workpiece 1. Furthermore, the length (the length corresponding to the length L of the connecting portion 4) for changing the appropriate condition to the capability reduction condition was changed every 2 mm in the range of 2 mm to 10 mm. In the experiment, there was one variable and the other conditions were kept under proper conditions.

  As a result of the above experiment, when cutting a steel plate having a small thickness, for example, a steel plate having a thickness of 6 mm, when the speed condition is 150%, the connecting portion 4 is in the range of 2 mm to 10 mm when the length to be changed to the capacity reduction condition is set. It has been found that a normal severing and cutting is performed without forming. Further, when the speed condition is set to 200%, it has been found that when the length to be changed to the capacity reduction condition is 2 mm to 6 mm, the normal disconnection and cutting is performed without forming the connection portion 4.

  When the speed condition was set to 250% to 350%, it was possible to form a good connection portion 4 in a range where the length changed to the capacity reduction condition was larger than 6 mm (see FIG. 3). As shown in the figure, the shape of the connecting portion 4 is a substantially triangular shape, and the area can be increased as the ability deterioration condition is made more severe.

  Further, when the plate thickness is increased, for example, when cutting a steel plate having a thickness of 12 mm, when the speed condition is set to 150%, the connecting portion 4 is changed in the range of 2 mm and 4 mm to be changed to the capacity reduction condition. Although normal separation and cutting were performed without forming, it was possible to form a good connection portion 4 in the range where the length was larger than 6 mm (see FIG. 4).

  Further, it was found that when the speed condition is 200%, normal disconnection is performed without forming the connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm. When the length is 6 mm, it is possible to form a good connection portion 4, but when the length is larger than 8 mm, cutting itself is impossible.

  Further, it was found that when the speed condition is in the range of 250% and 300%, a normal disconnection and cutting is performed without forming the connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm. When the length is 4 mm, a good connecting portion 4 can be formed, but when it is larger than 6 mm, cutting itself is impossible.

  Further, it was found that when the speed condition is 350%, normal disconnection and cutting are performed without forming the connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm. When the length was larger than 4 mm, cutting itself was impossible.

  Also, when cutting a steel plate with a plate thickness of 16 mm, if the speed condition is 150%, a normal disconnect cutting without forming the connection part 4 in the range of 2 mm and 4 mm to be changed to the capacity reduction condition. However, in the range where the length is larger than 6 mm, it was possible to form a good connection portion 4.

  Further, when the speed condition is 200%, it has been found that when the length to be changed to the capacity reduction condition is 2 mm and 4 mm, the normal cutting is performed without forming the connection portion 4. When the length was 6 mm, cutting itself was impossible.

  Further, when the speed condition is 250%, it has been found that when the length to be changed to the capacity reduction condition is 2 mm, normal disconnection cutting is performed without forming the connection portion 4. When the length is 4 mm, a good connecting portion 4 can be formed, but when it is larger than 6 mm, cutting itself is impossible.

  Further, it was found that when the speed condition was set to 300% and 350%, normal disconnection / cutting was performed without forming the connection portion 4 when the length to be changed to the capacity reduction condition was 2 mm. When the length was larger than 4 mm, cutting itself was impossible.

  Furthermore, when cutting a steel plate having a thickness of 19 mm, when the speed condition is 150%, a normal cutting is performed without forming the connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm. However, it was possible to form an excellent connection portion 4 in the range where the length was larger than 4 mm.

  In addition, when the speed condition is in the range of 200% to 300%, it is possible to form a good connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm. When the length was larger than 4 mm, cutting itself was impossible. Further, when the speed condition was 350%, cutting itself was impossible even when the length of the capacity reduction condition was 2 mm.

  Furthermore, when cutting a steel sheet having a plate thickness of 22 mm, when the speed condition is in the range of 150% to 350%, a good connection portion 4 can be formed when the length to be changed to the capacity reduction condition is 2 mm. It was possible. However, in the range where the length is larger than 4 mm, cutting itself was impossible.

  Although it changes according to the board thickness which should be cut | disconnected from the said result, when cutting conditions are selected, the process of cutting the figure 2 from the to-be-cut material 1 by setting the capability fall condition raised rather than the appropriate speed Thus, it can be said that the connecting portion 4 can be formed.

  The average output condition was changed so that the duty ratio of the appropriate output was decreased every 10% in the range of 10% to 30%. When cutting a steel plate with a plate thickness of 6 mm, when the duty ratio is reduced by 10% or 20%, the length to be changed to the capability reduction condition is in the range of 2 mm to 10 mm without forming the connection part 4, It was found that separation and cutting were performed (see FIG. 5).

  Further, it was found that when the duty ratio is reduced by 30%, normal disconnection / cutting is performed without forming the connecting portion 4 when the length to be changed to the capacity reduction condition is 2 mm or 4 mm. However, it was possible to form a good connection portion 4 in a range where the length to be changed to the capacity reduction condition was larger than 6 mm. As shown in FIG. 5, the shape of the connection part 4 becomes a substantially square shape, and it is possible to increase the area as the performance degradation condition becomes severe.

  When cutting a steel plate having a thickness of 12 mm, when the duty ratio is reduced by 10%, normal disconnection and cutting can be performed without forming the connecting portion 4 in the range of 2 mm to 10 mm which is changed to the capacity reduction condition. It was found that this was done (see FIG. 6).

  Further, it was found that when the duty ratio is reduced by 20%, normal disconnection and cutting are performed without forming the connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm and 4 mm. Further, when the length to be changed to the capacity reduction condition was 6 mm, it was possible to form a good connection portion 4, but when it was 8 mm, normal disconnection and cutting were performed.

  Further, it was found that when the duty ratio is reduced by 30%, normal disconnection and cutting are performed without forming the connection portion 4 in the length range of 2 mm to 6 mm which is changed to the capacity reduction condition. However, in the range where the length to be changed to the capacity reduction condition is larger than 8 mm, cutting itself was impossible.

  When cutting a steel plate with a plate thickness of 16 mm, when the duty ratio is reduced by 10% or 20%, the length to be changed to the capacity reduction condition is in the range of 2 mm to 10 mm without forming the connection part 4, It has been found that detachment is performed.

  Further, when the duty ratio was decreased by 30%, cutting itself was impossible within the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  When cutting a steel plate with a plate thickness of 19 mm, when the duty ratio is reduced by 10%, normal disconnection cutting is possible without forming the connecting portion 4 in the range of 2 mm to 10 mm which is changed to the capacity reduction condition. It turned out to be done.

  Further, it was found that when the duty ratio is reduced by 20%, normal disconnection and cutting are performed without forming the connecting portion 4 when the length to be changed to the capacity reduction condition is 2 mm. Moreover, it was possible to form the favorable connection part 4 in the range whose length changed to capability fall conditions is larger than 4 mm.

  Further, when the duty ratio was decreased by 30%, cutting itself was impossible within the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  When cutting a steel sheet with a plate thickness of 22 mm, when the duty ratio is reduced by 10%, normal disconnection cutting can be performed without forming the connection portion 4 in the range where the length to be changed to the capacity reduction condition is 2 mm to 10 mm. It turned out to be done.

  Further, it was found that when the duty ratio is reduced by 20%, normal disconnection and cutting are performed without forming the connecting portion 4 when the length to be changed to the capacity reduction condition is 2 mm. In addition, when the length to be changed to the capacity reduction condition is 4 mm to 8 mm, it was possible to form a good connection portion 4, but when it was 10 mm, cutting was impossible.

  In addition, when the duty ratio was reduced by 30%, it was possible to form a good connection portion 4 when the length to be changed to the capability reduction condition was 2 mm. However, in the range where the length to be changed to the capacity reduction condition is larger than 4 mm, cutting itself was impossible.

  Although it changes according to the plate | board thickness which should be cut | disconnected from the said result, when an average output condition is selected, the figure 2 from the to-be-cut material 1 is set by setting the capability fall condition which reduced the duty ratio rather than appropriate output. It can be said that it is possible to form the connection part 4 in the process of cutting.

  The pressure condition was changed so as to decrease every 10% within a range of 10% to 30% from the appropriate pressure. When a steel plate having a thickness of 6 mm is cut, the appropriate pressure is 0.034 MPa. It has been found that when the appropriate pressure is reduced by 10%, normal disconnection and cutting are performed without forming the connecting portion 4 in the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  In addition, when the pressure condition was reduced by 20%, it was possible to form a good connection portion 4 in a range where the length changed to the ability reduction condition was larger than 10 mm. In addition, when the pressure condition was reduced by 30%, it was possible to form a good connection portion 4 in a range where the length changed to the ability reduction condition was larger than 6 mm.

  Moreover, when cutting a steel plate having a plate thickness of 12 mm, the appropriate pressure is 0.041 MPa. It has been found that when the appropriate pressure is reduced by 10%, normal disconnection and cutting are performed without forming the connecting portion 4 in the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  In addition, when the pressure condition was reduced by 20%, it was possible to form a good connection portion 4 in a range where the length changed to the ability reduction condition was larger than 10 mm. Further, when the pressure condition was lowered by 30, it was possible to form a good connection portion 4 in a range where the length to be changed to the ability reduction condition was larger than 6 mm.

  When cutting a steel plate having a thickness of 16 mm, the appropriate pressure is 0.041 MPa, and a shield gas made of oxygen gas is injected outside the assist gas. It has been found that when the appropriate pressure is reduced by 10%, normal disconnection and cutting are performed without forming the connecting portion 4 in the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  Further, when the pressure condition was reduced by 20%, it was possible to form a good connection portion 4 in a range where the length to be changed to the capability reduction condition was larger than 8 mm. Further, when the pressure condition was reduced by 30%, it was possible to form a good connection part 4 in a range where the length changed to the ability reduction condition was larger than 4 mm.

  Further, when a steel plate having a thickness of 19 mm is cut, the appropriate pressure is 0.041 MPa, and a shielding gas made of oxygen gas is injected outside the assist gas. It has been found that when the appropriate pressure is reduced by 10%, normal disconnection and cutting are performed without forming the connecting portion 4 in the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  Further, when the pressure condition was reduced by 20%, it was possible to form a good connection portion 4 when the length to be changed to the ability reduction condition was in the range of 4 mm to 8 mm. However, when it was 10 mm, cutting was impossible. Further, when the pressure condition was reduced by 30%, it was possible to form a good connection portion 4 when the length to be changed to the ability reduction condition was in the range of 2 mm to 4 mm. However, cutting was impossible in a range larger than 6 mm.

  Further, when a steel plate having a thickness of 22 mm is cut, the appropriate pressure is 0.040 MPa, and a shield gas made of oxygen gas is injected outside the assist gas. It has been found that when the appropriate pressure is reduced by 10%, normal disconnection and cutting are performed without forming the connecting portion 4 in the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  Further, when the pressure condition was reduced by 20%, it was possible to form a good connection portion 4 when the length to be changed to the capability reduction condition was in the range of 4 mm to 6 mm. However, cutting was impossible in a range larger than 8 mm. Further, when the pressure condition was reduced by 30%, cutting itself was impossible within the range of 2 mm to 10 mm for changing to the capacity reduction condition.

  Although it changes according to the plate | board thickness which should be cut | disconnected from the said result, when pressure conditions are selected, the process of cutting the figure 2 from the to-be-cut material 1 by setting the capability fall conditions reduced rather than the appropriate pressure Thus, it can be said that the connecting portion 4 can be formed.

  The focus condition was changed so as to enter the inside every 2 mm within a range of 2 mm to 6 mm from the surface of the workpiece 1. When cutting a steel plate with a plate thickness of 6 mm, when the focus condition is 2 mm to 6 mm, normal disconnection without forming the connection portion 4 in the range of 2 mm to 10 mm to be changed to the capacity reduction condition. It was found that the cutting was done.

  Further, when cutting a steel plate having a thickness of 12 mm, when the focus condition is 2 mm, the normal cutting can be performed without forming the connection portion 4 in the range of 2 mm to 10 mm to be changed to the capacity reduction condition. It turned out to be done. When the focus condition is 4 mm, it is possible to form a good connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm to 10 mm. Further, when the focus condition was 6 mm, cutting itself was impossible.

  Also, when cutting a steel plate with a plate thickness of 16 mm, if the focus condition is 2 mm, normal disconnection and cutting can be performed without forming the connecting portion 4 in the range of 2 mm to 10 mm to be changed to the capacity reduction condition. It turned out to be done. When the focus condition is 4 mm, it has been found that when the length to be changed to the capability reduction condition is 2 mm, the normal disconnection and cutting is performed without forming the connection portion 4. When the length was 4 mm to 8 mm, it was possible to form a good connecting portion 4, but when the length was 10 mm, cutting was impossible. Further, when the focus condition was 6 mm, cutting itself was impossible.

  Further, when cutting a steel plate having a thickness of 19 mm, when the focus condition is set to 2 mm, normal disconnection cutting is performed without forming the connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm. It has been found. When the length is 4 mm to 10 mm, it is possible to form a good connection portion 4. Further, when the focus condition was 4 mm and 6 mm, cutting itself was impossible.

  Further, when a steel plate having a thickness of 22 mm is cut, when the focus condition is set to 2 mm, it is possible to form a good connection portion 4 when the length to be changed to the capacity reduction condition is 2 mm to 6 mm. However, cutting was impossible in a range larger than 8 mm. When the focal conditions were 4 mm and 6 mm, cutting itself was impossible within the range of 2 mm to 10 mm in which the length was changed to the ability reduction condition.

  Although it changes according to the plate | board thickness which should be cut | disconnected from the said result, when a focus condition is selected, by setting the capability fall condition which made the focus position fall from the surface of the to-be-cut | disconnected material 1, from the to-be-cut | disconnected material 1 It can be said that the connecting portion 4 can be formed in the process of cutting the figure 2.

  The laser cutting method of the present invention configured as described above is advantageous when used for cutting a plurality of products from a large-sized workpiece.

DESCRIPTION OF SYMBOLS 1 Material to be cut 2 Shape, product 3 Path | route, planned cutting line, kerf 4 Connection part 11 Cutting surface plate 12 Rail 15 Frame 16 Traverse carriage 17 Laser cutting nozzle 18 Laser oscillator 19 Control panel 20 Laser cutting device

Claims (2)

The laser cutting nozzle is made to correspond to the target figure at the cutting speed suitable for cutting the material to be cut from the laser cutting nozzle, the average output of the laser, the assist gas pressure, and the focal position of the laser beam. When moving along the route and cutting,
In some sections in the process of moving the laser cutting nozzle along the path corresponding to the target figure,
Conditions for increasing the cutting speed higher than the cutting speed suitable for cutting the workpiece,
Conditions for lowering the average output of the laser below the average output of the laser suitable for cutting the workpiece,
Conditions for lowering the assist gas pressure below the assist gas pressure suitable for cutting the material to be cut,
A condition for moving the focal position of the laser beam in the inner direction of the thickness of the material to be cut from the focal position suitable for cutting the material to be cut;
Laser cutting characterized by forming a connecting portion for connecting a material to be cut and a target figure by selecting one condition or a plurality of conditions from the conditions and reducing the cutting ability for the material to be cut Method. The material to be cut and the target figure are connected by reducing the cutting ability for the material to be cut in a part of the process in which the laser cutting nozzle is moved along a path corresponding to the target figure. After forming the connection part, the cutting speed suitable for cutting the material to be cut, the average laser output, the assist gas pressure, the path where the laser cutting nozzle corresponds to the target figure by returning to the focal position of the laser beam The laser cutting method according to claim 1, wherein the laser cutting method is performed by cutting with a laser beam.