Cutter and cutting method

Abstract

A cutting machine comprises an injection unit capable of cutting a workpiece by injecting a laser and an assist gas into the workpiece, a switching unit capable of supplying a first gas and a second gas having a higher nitrogen concentration than the first gas as the assist gas to the injection unit and switching the assist gas supplied to the injection unit, and a control unit capable of changing the assist gas supplied by the switching unit to the injection unit by controlling the switching unit, wherein the injection unit can change the cutting speed of cutting the workpiece to a first speed or a second speed slower than the first speed, and the control unit changes the assist gas supplied to the injection unit based on the cutting speed.

Description

Technology Field

[0001] The present disclosure relates to a cutting machine and a cutting method.

[0002] The present application claims priority based on patent application No. 2024-012891 filed in Japan on January 31, 2024, and incorporates the contents thereof herein. Background Technology

[0003] Conventionally, there are laser cutting machines that laser cut workpieces such as steel plates. Types of laser cutting machines include, for example, bed type and gantry type.

[0004] A bed-type laser cutter is a laser cutter in which a cutting head moves to perform laser cutting on a workpiece placed on a table inside the machine cover. A bed-type laser cutter is a small and lightweight laser cutter. A bed-type laser cutter is also called a table-type laser cutter.

[0005] A gantry-type laser cutter is a laser cutter in which a gantry-type cutter body travels along a rail to cut the workpiece. A gantry-type laser cutter is a large and heavy laser cutter. A gantry-type laser cutter is also called a gantry-type laser cutter.

[0006] Conventionally, in laser cutting for cutting mild steel and the like, oxygen gas is often used as the assist gas. In recent years, as the power output of lasers has increased, laser cutting using nitrogen gas, which does not rely on oxidation reactions, has also become common for the purpose of achieving higher speeds.

[0007] In laser cutting using nitrogen gas as an assist gas, dross adheres to the back side of the cut surface, so post-processing such as grinding is required after laser cutting. As a laser cutting method to improve dross adhesion, there is a laser cutting method that uses a mixed gas, in which a small amount of oxygen gas or compressed air is mixed with nitrogen gas, as an assist gas (e.g., Patent Document 1).

[0008] Laser cutting using a mixed gas reduces the amount of attached dross compared to laser cutting using nitrogen gas in high-speed cutting, but tends to increase the amount of attached dross compared to laser cutting using nitrogen gas in low-speed cutting.

[0009] In cutting fine shapes such as small circles, it may be necessary to lower the cutting speed to ensure cutting precision, and there is a possibility that the amount of dross attached may increase by using a mixed gas.

[0010] Bed-type laser cutters do not require a significant reduction in cutting speed even when cutting fine shapes, so they can cut various shapes using the same mixed gas. Prior art literature

[0011] Japanese Patent Publication No. 2001-353588 The problem to be solved

[0012] However, compared to bed-type laser cutters, gantry-type laser cutters have a large variation in speed depending on the cutting shape. Therefore, in gantry-type laser cutters, when using mixed gas to suppress the amount of dross, there is a concern that the cutting shape may be limited.

[0013] Taking the above circumstances into account, the present disclosure aims to provide a cutting machine and a cutting method that suppress dross adhesion without relying on the cutting shape of the workpiece. means of solving the problem

[0014] A cutting machine according to a first aspect of the present disclosure comprises: an injection unit capable of cutting a workpiece by injecting a laser and an assist gas into the workpiece; a switching unit capable of switching the assist gas supplied to the injection unit, wherein a first gas and a second gas having a higher nitrogen concentration than the first gas are supplied to the injection unit as the assist gas; and a control unit capable of changing the assist gas supplied to the injection unit by the switching unit by controlling the switching unit. The injection unit is capable of changing the cutting speed of cutting the workpiece to a first speed or a second speed slower than the first speed, and the control unit changes the assist gas supplied to the injection unit based on the cutting speed.

[0015] A cutting method according to a second aspect of the present disclosure is a cutting method for cutting a workpiece by injecting a laser and an assist gas into the workpiece, wherein, based on the cutting speed of cutting the workpiece, the assist gas injected into the workpiece is converted into a first gas or a second gas having a higher nitrogen concentration than the first gas.

[0016] A cutting machine according to a third aspect of the present disclosure comprises: an injection unit capable of cutting a workpiece by injecting a laser and an assist gas into the workpiece; a switching unit capable of switching the assist gas supplied to the injection unit, wherein a first gas and a second gas having a higher nitrogen concentration than the first gas are supplied to the injection unit as the assist gas; and a control unit capable of changing the assist gas supplied to the injection unit by the switching unit by controlling the switching unit. The control unit changes the assist gas supplied to the injection unit based on the cutting area of ​​the workpiece that the injection unit cuts.

[0017] A cutting method according to a fourth aspect of the present disclosure is a cutting method for cutting a workpiece by injecting a laser and an assist gas into the workpiece, wherein, based on the cutting area of ​​the workpiece, the assist gas injected into the workpiece is converted into a first gas or a second gas having a higher nitrogen concentration than the first gas. Effects of the invention

[0018] According to the cutting machine and cutting method of the present disclosure, a cutting machine and cutting method that suppress dross adhesion without relying on the cutting shape of the workpiece can be provided. Brief explanation of the drawing

[0019] FIG. 1 is a perspective view schematically showing a cutter according to one embodiment of the present disclosure. Figure 2 is a block diagram schematically illustrating the method of supplying assist gas in a copper cutter. Figure 3 is a photograph showing the back side of a workpiece that has been cut around the outer edge using a first gas. Figure 4 is a photograph showing the back side of a workpiece that has been cut around the outer edge using a second gas. Figure 5 is a photograph showing the back side of a workpiece that has undergone small hole cutting using a second gas. Figure 6 is a photograph showing the back side of a workpiece that has undergone small hole cutting using a first gas. Specific details for implementing the invention

[0020] (First embodiment)

[0021] Hereinafter, a first embodiment of the present disclosure will be described with reference to the drawings.

[0022] FIG. 1 is a perspective view schematically showing a cutter (1) according to one embodiment of the present disclosure.

[0023] FIG. 2 is a block diagram schematically illustrating the method of supplying assist gas in a cutter (1).

[0024] The cutter (1) is equipped with a workbench (10), a cutter body (20), an operation deck (30), an operation section (40), a control section (50), and a switching section (60). The cutter (1) is a device for cutting a workpiece, such as a steel plate, placed on the workbench (10), and is a gantry-type laser cutter in which the gantry-type cutter body is capable of traveling on a rail.

[0025] In this embodiment, the vertical direction of the cutter (1) is defined as the "up-down direction (Z)," the vertical upward direction as the "upward direction (Z1)" in the up-down direction (Z), and the vertical downward direction as the "downward direction (Z2)" in the up-down direction (Z). Additionally, among the horizontal directions perpendicular to the up-down direction (Z), the direction in which the cutter (1) travels is defined as the "travel direction (X)," the direction in which the cutter (1) moves forward is defined as the "forward direction (X1)" in the travel direction (X), and the direction opposite to the forward direction (X1), in which the cutter (1) moves backward, is defined as the "rear direction (X2)" in the travel direction (X). Furthermore, the direction perpendicular to the up-down direction (Z) and the travel direction (X) is defined as the "width direction (Y)," one side in the width direction (Y) is defined as the "left direction (Y1)," and the other side is defined as the "right direction (Y2)" in the width direction (Y).

[0026] The workpiece plate (10) is a platform capable of supporting a workpiece to be cut by a cutter (1) on the surface above (Z1), and is formed in a rectangular shape when viewed from the top (Z1) plane. The workpiece plate (10) is placed on the ground or floor surface. The workpiece supported on the workpiece plate (10) is, for example, a steel plate formed from mild steel.

[0027] The cutter body (20) is configured to be traversable on a pair of rails (R) arranged along the driving direction (X) and positioned above (Z1) the platen (10). As shown in FIG. 1, the rails (R) are positioned on the left (Y1) and right (Y2) sides of the platen (10).

[0028] The cutter body (20) is equipped with a carriage (21), a drive unit (22), a body cover unit (25), a cutting head (injection unit) (27), an area sensor (28), and an alarm unit (29).

[0029] The trolley (21) is a gantry-type frame that is movable in the driving direction (X) above (Z1) the platen (10). The cutter body (20) moves in the driving direction (X) as the trolley (21) travels on the rail (R).

[0030] The drive unit (22) is provided on a rail (R) and has a wheel (not shown) that is rotatable with respect to the rail (R), and an electric motor (not shown), such as an electric motor, that can rotate the wheel with an axis extending in the width direction (Y) as the center of rotation.

[0031] The drive unit (22) moves the bogie (21) by rotating the wheel by means of an electric motor and moves the cutter body (20) in the driving direction (X). The cutter body (20) is equipped with a pair of drive units (22). The pair of drive units (22) are provided corresponding to a pair of rails (R) provided on the left side (Y1) and right side (Y2) of the platen (10).

[0032] The body cover portion (25) is provided above (Z1) the trolley (21) and is a member that covers the cutting space for cutting a workpiece placed on the platen (10). By covering the cutting space with the body cover portion (25), the inner side (cutting space) and the outer side of the cutter (1) can be partitioned, thereby improving safety during the cutting operation.

[0033] The gas cover portion (25) may be configured to be able to open and close the aforementioned cutting space. Additionally, the gas cover portion (25) may be configured such that a plurality of gas cover portions (25) are arranged side by side in the width direction (Y) and each of the plurality of gas cover portions (25) opens and closes independently.

[0034] The cutting head (injection part) (27) is a cutting device capable of cutting a workpiece placed on a platen (10). The cutting head (27) is provided in the aforementioned cutting space covered by the body cover part (25).

[0035] The cutting head (27) is provided to be movable in the width direction (Y). For example, the cutting head (27) is provided on a rail extending in the width direction (Y) and configured to be movable in the width direction (Y) along the rail. Additionally, the cutting head (27) is provided to be movable in the vertical direction (Z).

[0036] A cutting torch (not shown) is provided at the lower end (Z2) of the cutting head (27). The cutting head (27) laser cuts the workpiece by injecting assist gas and a laser beam from the cutting torch onto the workpiece. As for the laser ejected from the cutting head (27), for example, a fiber laser with an output of 1 kW or more may be used.

[0037] The cutting head (27) can move in the driving direction (X) relative to the workpiece as the cutter body (20) travels along the rail (R) in the driving direction (X). Additionally, the cutting head (27) is provided on the cutter body (20) so as to be movable in the width direction (Y) and the up-down direction (Z) as described above. Therefore, the cutting head (27) can move in the up-down direction (Z), the width direction (Y), and the driving direction (X) relative to the workpiece, and cuts the workpiece by moving in any direction.

[0038] The area sensor (28) is provided at the front (X1) of the gas cover part (25), as shown in FIG. 1. The cutter body (20) is equipped with a pair of area sensors (28) provided at the left (Y1) and right (Y2) sides of the gas cover part (25).

[0039] The area sensor (28) is a sensor capable of detecting an object blocking an area between a pair of area sensors (28). The area sensor (28) is provided as a safety device in the cutter (1).

[0040] The alarm unit (29) is a warning light provided protruding upward (Z1) from the main body (20) of the cutter. The alarm unit (29) is an alarm device that alerts to danger by illuminating the warning light. For example, the control unit (50) described later acquires the detection result of the area sensor (28) and controls the alarm unit (29) based on the acquired detection result to illuminate the warning light.

[0041] The operation deck (30) is provided on the left side (Y1) of the cutter body (20) and is a work deck that can be boarded by a worker. The operation deck (30) is equipped with a door that can open and close the cutting space described above. The worker can board the operation deck (30) and perform maintenance on the cutting head (27) by opening the door. In addition, the worker's safety can be ensured by closing the door when cutting the workpiece.

[0042] The control unit (40) is provided above (Z1) the control deck (30) and is an input device that allows an operator to input operations to the cutter (1). The control unit (40) is equipped with, for example, a display device such as a display capable of displaying various information, and buttons capable of inputting operations to the cutter (1). The control unit (40) may also have a touch panel capable of inputting operations to the cutter (1).

[0043] The control unit (50) is a control device capable of controlling part or all of the cutter (1). The control unit (50) is provided at the rear (X2) of the cutter body (20). The control unit (50) controls the cutter (1) based on, for example, an operation input to the operation unit (40), and causes the cutting head (27) to cut the workpiece placed on the platen (10).

[0044] The control unit (50) is, for example, a program-executable device (computer) equipped with a processor, memory, and a storage unit. Each function of the control unit (50) is realized by one or more processors, such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), executing a program stored in program memory. However, all or part of these functions may be realized by hardware (e.g., circuitry) such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or PLD (Programmable Logic Device). Additionally, all or part of the above functions may be realized by a combination of software and hardware. The storage unit is realized by flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), ROM (Read-Only Memory), or RAM (Random Access Memory).

[0045] The switching unit (60) is a switching device capable of switching the assist gas ejected from the cutting head (27). The switching unit (60) is, for example, a three-way valve capable of opening and closing the path of the assist gas. The control unit (50) controls the switching unit (60) so that the switching unit (60) performs the switching of the assist gas.

[0046] As shown in FIG. 2, a first gas (GA) and a second gas (GB) are introduced into the switching section (60). The first gas (GA) and the second gas (GB) are assist gases used when the cutter (1) cuts the workpiece.

[0047] The control unit (50) changes the assist gas flowing into the cutting head (27) by opening and closing a flow path within the switching unit (60) so that either the first gas (GA) or the second gas (GB) flows into the cutting head (27).

[0048] The first gas (GA) is a mixed gas comprising nitrogen gas and a gas other than nitrogen gas. In the first gas (GA), the gas mixed with nitrogen gas may be oxygen gas or air. Additionally, inert gases such as helium gas and argon gas may be used instead of nitrogen gas. The oxygen concentration of the first gas (GA) is preferably 10% or less.

[0049] The second gas (GB) is an assist gas with a higher nitrogen concentration than the first gas (GA). The second gas (GB) is, for example, a high-purity nitrogen gas with a nitrogen purity of 99.999% or higher.

[0050] In the cutter (1), the first gas (GA) and the second gas (GB) are used under gas conditions, for example, a pressure of 0.5 MPa or higher and a flow rate of 50 m³ / h or higher.

[0051] The control unit (50) switches the assist gas flowing from the switching unit (60) to the cutting head (27) based on the cutting speed at the cutting head (27). For example, the control unit (50) switches the assist gas based on the cutting speed entered by the operator to the operating unit (40).

[0052] Generally, when cutting a workpiece with a laser cutter, the cutting speed is determined based on the cutting shape.

[0053] In a gantry-type cutter (1), when cutting the outer edge of a workpiece, it is preferable to set the cutting speed at the cutting head (27) to a high-speed range. Also, when cutting fine shapes such as small holes, it is preferable to set the cutting speed at the cutting head (27) to a low-speed range.

[0054] In the following description, the cutting speed when the cutter (1) cuts the workpiece in a high-speed range is referred to as the first speed. Also, the cutting speed when the cutter (1) cuts the workpiece in a low-speed range is referred to as the second speed.

[0055] The first speed is a cutting speed faster than the second speed and is primarily used for cutting the outer periphery of a workpiece. When performing outer periphery cutting on a workpiece, the cutting time can be shortened by cutting at the first speed.

[0056] The second speed is a cutting speed primarily used for cutting fine shapes, such as small holes. When cutting fine shapes, such as small holes, on a workpiece, cutting precision can be ensured by cutting at a second speed that is slower than the first speed.

[0057] Here, the first speed and the second speed are distinguished based on a predetermined value and are speed ranges having a predetermined width. The first speed, which is a high-speed range, is a cutting speed greater than or equal to a predetermined value. The second speed, which is a low-speed range, is a cutting speed less than a predetermined value. For example, the first speed represents a cutting speed of 3000 mm / min or more. For example, the second speed represents a cutting speed of less than 3000 mm / min.

[0058] The control unit (50) controls the switching unit (60) when the cutting speed is the first speed to inject the first gas (GA) as an assist gas from the cutting head (27).

[0059] FIG. 3 is a photograph showing the back side of a workpiece that has been cut around the periphery using a first gas (GA). That is, FIG. 3 is a photograph showing the back side of a workpiece that has been cut under the cutting conditions of a first gas (GA) and a first speed.

[0060] FIG. 4 is a photograph showing the back side of a workpiece cut using a second gas (GB). That is, FIG. 4 is a photograph showing the back side of a workpiece cut using a second gas (GB) and also under cutting conditions of a first speed.

[0061] The workpiece shown in FIGS. 3 and 4 is an SS400 material with a plate thickness of 12 mm. In addition, the workpiece shown in FIGS. 3 and 4 is a workpiece cut at a cutting speed of 5500 mm / min.

[0062] As shown in FIGS. 3 and 4, the amount of dross attached to the back surface of the workpiece shown in FIG. 3 is less than the amount of dross attached to the back surface of the workpiece shown in FIG. 4. That is, when the workpiece is cut at a first speed, the amount of dross attached to the back surface of the workpiece cut using the first gas (GA) as the assist gas is less than the amount of dross attached to the back surface of the workpiece cut using the second gas (GB) as the assist gas.

[0063] The control unit (50) controls the switching unit (60) when the cutting speed is the second speed to inject the second gas (GB) as an assist gas from the cutting head (27).

[0064] FIG. 5 is a photograph showing the back side of a workpiece that has undergone small hole cutting using a second gas (GB). That is, FIG. 5 is a photograph showing the back side of a workpiece that has been cut under the conditions of a second gas (GB) and a second speed.

[0065] FIG. 6 is a photograph showing the back side of a workpiece that has undergone small hole cutting using a first gas (GA). That is, FIG. 6 is a photograph showing the back side of a workpiece that has been cut under the cutting conditions of a first gas (GA) and a second speed.

[0066] The workpiece shown in FIGS. 5 and 6 is an SS400 material with a plate thickness of 12 mm. In addition, the workpiece shown in FIGS. 5 and 6 is a workpiece cut at a cutting speed of 1000 mm / min.

[0067] As shown in FIGS. 5 and 6, the amount of dross attached to the back surface of the workpiece shown in FIG. 5 is less than the amount of dross attached to the back surface of the workpiece shown in FIG. 6. That is, when the workpiece is cut at a second speed, the amount of dross attached to the back surface of the workpiece cut using the second gas (GB) as the assist gas is less than the amount of dross attached to the back surface of the workpiece cut using the first gas (GA) as the assist gas.

[0068] When the control unit (50) determines that the cutting speed for cutting the workpiece is the first speed, it switches the flow path within the switching unit (60) so that the first gas (GA) is ejected from the cutting head (27). When the control unit (50) determines that the cutting speed for cutting the workpiece is the second speed, it switches the flow path within the switching unit (60) so that the second gas (GB) is ejected from the cutting head (27).

[0069] In the memory unit of the control unit (50), a cutting condition database in which the cutting speed and the assist gas are correlated is stored. The control unit (50) refers to the cutting condition database and selects the assist gas based on the cutting speed. The control unit (50) controls the switching unit (60) based on the selected assist gas to change the assist gas ejected from the cutting head (27).

[0070] According to the cutting machine (1) of the present embodiment, it comprises an injection unit (cutting head) (27) capable of cutting a workpiece by injecting a laser and an assist gas into the workpiece, a first gas (GA) and a second gas (GB) having a higher nitrogen concentration than the first gas (GA) as assist gas, a switching unit (60) capable of switching the assist gas supplied to the injection unit (27), and a control unit (50) capable of changing the assist gas supplied by the switching unit (60) to the injection unit (27) by controlling the switching unit (60).

[0071] The injection unit (27) can change the cutting speed of the workpiece to a first speed or a second speed slower than the first speed. The control unit (50) changes the assist gas supplied to the injection unit (27) based on the cutting speed.

[0072] For example, the control unit (50) supplies a first gas (GA) from the switching unit (60) to the injection unit (27) when the cutting speed is a first speed, and supplies a second gas (GB) from the switching unit (60) to the injection unit (27) when the cutting speed is a second speed.

[0073] As a result, even if it is necessary to change the cutting speed based on the cutting shape of the workpiece, a cutting machine (1) and a cutting method that suppress dross attachment without relying on the cutting shape of the workpiece can be provided.

[0074] (Second embodiment)

[0075] A cutter (1A) according to a second embodiment of the present disclosure will be described. In the following description, components common to those already described will be given the same reference numerals and redundant descriptions will be omitted.

[0076] The cutter (1A) is equipped with a plate (10), a cutter body (20), an operation deck (30), an operation unit (40), a control unit (50A), and a switching unit (60).

[0077] The control unit (50A) is a control device capable of controlling part or all of the cutter (1A), similar to the control unit (50) of the first embodiment. The control unit (50A) controls the cutter (1A) based on, for example, an operation input to the operating unit (40), and causes the cutting head (27) to cut the workpiece placed on the platen (10).

[0078] The control unit (50A), like the control unit (50) of the first embodiment, opens and closes a flow path within the switching unit (60) so that either the first gas (GA) or the second gas (GB) flows into the cutting head (27), thereby switching the assist gas flowing into the cutting head (27).

[0079] The control unit (50A) switches the assist gas flowing from the switching unit (60) to the cutting head (27) based on the cutting area of ​​the workpiece being cut by the cutting head (27). For example, the control unit (50A) switches the assist gas based on the cutting area entered by the operator in the operating unit (40).

[0080] In the following description, among the cutting areas where the cutter (1) cuts the workpiece, the cutting area when the outer edge is cut, which is larger than the cutting area of ​​a fine shape such as a small hole, is referred to as the first area. Additionally, the cutting area when cutting a fine shape such as a small hole, which is smaller than the first area, is referred to as the second area.

[0081] Here, the first area and the second area are distinguished based on a predetermined value and are area regions having a predetermined width. The first area is a shape area greater than or equal to the predetermined value. The second area is a shape area less than the predetermined value. For example, the first area represents a shape area of ​​400 mm² or more. The second area represents a shape area of ​​less than 400 mm².

[0082] The control unit (50A) controls the switching unit (60) when the cutting area is the first area to inject the first gas (GA) as an assist gas from the cutting head (27).

[0083] As described above, FIG. 3 is a photograph showing the back side of a workpiece that has been cut around the outer edge using a first gas (GA). That is, FIG. 3 shows a workpiece cut using a first gas (GA) when the cutting area is the first area.

[0084] As described above, FIG. 4 is a photograph showing the back side of a workpiece that has been cut around the outer edge using a second gas (GB). That is, FIG. 4 shows a workpiece cut using a second gas (GB) when the cutting area is the first area.

[0085] As shown in FIGS. 3 and 4, when the cutting area of ​​the workpiece is the first area, the amount of dross attached to the back surface of the workpiece cut using the first gas (GA) as the assist gas is less than the amount of dross attached to the back surface of the workpiece cut using the second gas (GB) as the assist gas.

[0086] The control unit (50A) controls the switching unit (60) when the cutting area is the second area to inject the second gas (GB) as an assist gas from the cutting head (27).

[0087] As described above, FIG. 5 is a photograph showing the back side of a workpiece in which a small hole is cut using a second gas (GB). That is, FIG. 5 shows a workpiece cut using a second gas (GB) when the cutting area is the second area.

[0088] As described above, FIG. 6 is a photograph showing the back side of a workpiece in which a small hole is cut using a first gas (GA). That is, FIG. 6 shows a workpiece cut using a first gas (GA) when the cutting area is the second area.

[0089] As shown in FIGS. 5 and 6, when the cutting area of ​​the workpiece is the second area, the amount of dross attached to the back surface of the workpiece cut using the second gas (GB) as the assist gas is less than the amount of dross attached to the back surface of the workpiece cut using the first gas (GA) as the assist gas.

[0090] When the control unit (50A) determines that the cutting area for cutting the workpiece is the first area, it switches the flow path within the switching unit (60) so that the first gas (GA) is ejected from the cutting head (27). When the control unit (50A) determines that the cutting area for cutting the workpiece is the second area, it switches the flow path within the switching unit (60) so that the second gas (GB) is ejected from the cutting head (27).

[0091] In the memory unit of the control unit (50A), a cutting condition database in which the cutting area and the assist gas are corresponded is stored. The control unit (50A) refers to the cutting condition database and selects the assist gas based on the cutting area. The control unit (50A) controls the switching unit (60) based on the selected assist gas to change the assist gas ejected from the cutting head (27).

[0092] According to the cutting machine (1A) of the present embodiment, it comprises an injection unit (cutting head) (27) capable of cutting a workpiece by injecting a laser and an assist gas into the workpiece, a first gas (GA) and a second gas (GB) having a higher nitrogen concentration than the first gas (GA) as assist gas, a switching unit (60) capable of switching the assist gas supplied to the injection unit (27), and a control unit (50A) capable of changing the assist gas supplied by the switching unit (60) to the injection unit (27) by controlling the switching unit (60).

[0093] The control unit (50A) changes the assist gas supplied to the injection unit (27) based on the cutting area.

[0094] For example, the control unit (50A) supplies a first gas (GA) from the switching unit (60) to the injection unit (27) when the cutting area for cutting the workpiece is a first area, such as a large cutting area for an outer edge cut. Additionally, the control unit (50A) supplies a second gas (GB) from the switching unit (60) to the injection unit (27) when the cutting area for cutting the workpiece is a second area, such as a small hole cut, which is a smaller area than the first area.

[0095] As a result, a cutting machine (1A) and a cutting method that suppress dross adhesion without relying on the cutting shape of the workpiece can be provided.

[0096] Although each embodiment of the present disclosure has been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments and includes design modifications that do not deviate from the gist of the present disclosure. Furthermore, the components shown in each of the embodiments described above and the variations shown below can be configured by appropriately combining them.

[0097] (Variation Example 1)

[0098] In each of the above embodiments, the switching unit (60) switches the assist gas by a three-way valve, but the form of the switching unit is not limited thereto.

[0099] The switching unit may switch the assist gas by switching multiple gas circuits using an electronic valve. The switching unit may also switch the assist gas using a mass flow controller of high flow rate and high pressure specifications.

[0100] (Variation Example 2)

[0101] In each of the above embodiments, the cutter (1, 1A) switches the assist gas for each workpiece based on the cutting speed or cutting area, but the form of the cutter is not limited thereto. The cutter may switch the assist gas for each cutting location based on the cutting speed or cutting area.

[0102] For example, when performing circumference cutting and small hole cutting on the same workpiece, the cutting machine switches the assist gas based on the cutting speed or cutting area set for each cutting location.

[0103] In this case, the cutting machine uses a first gas (GA) when cutting a cutting point (e.g., outer circumference) at a first speed for the same workpiece, and uses a second gas (GB) when cutting a cutting point (e.g., small hole) at a second speed.

[0104] In addition, the cutting machine uses a first gas (GA) when cutting a cutting location (e.g., outer periphery) with a first cutting area for the same workpiece, and uses a second gas (GB) when cutting a cutting location (e.g., small hole) with a second cutting area.

[0105] (Variation Example 3)

[0106] In each of the above embodiments, the assist gas used by the cutter (1, 1A) is a first gas (GA) and a second gas (GB), but the types of assist gas used by the cutter are not limited thereto. The cutter may be configured to switch between three or more assist gases.

[0107] When there are three types of assist gases that can be switched by the switching unit, the control unit determines which of the three speed ranges (first speed, second speed, third speed) is distinguished by a predetermined value, and injects the assist gas corresponding to the determined cutting speed from the cutting head (27).

[0108] In addition, the control unit determines which of the three area regions (first area, second area, and third area) the cutting area is distinguished by a predetermined value, and injects an assist gas corresponding to the determined cutting area from the cutting head (27).

[0109] (Variation Example 4)

[0110] In each of the above embodiments, the cutter (1, 1A) is a gantry-type laser cutter, but it may also be a laser cutter other than a gantry-type, such as a bed type. Explanation of the symbols

[0111] 1, 1A: Cutter 10: Standard 20: Cutter body 27: Cutting head (injection part) 50, 50A: Control unit 60: Transition section Y: Driving direction X1: Forward X2: Rear Y: Width direction Y1: Left side Y2: Ally Z: Up / Down direction (Vertical direction) Z1: Up Z2: Downward

Claims

Claim 1 A cutting machine comprising: an injection unit capable of cutting a workpiece by injecting a laser and an assist gas into the workpiece; a switching unit capable of supplying a first gas and a second gas having a higher nitrogen concentration than the first gas as the assist gas to the injection unit and switching the assist gas supplied to the injection unit; and a control unit capable of changing the assist gas supplied to the injection unit by the switching unit by controlling the switching unit, wherein the injection unit can change the cutting speed of cutting the workpiece to a first speed or a second speed slower than the first speed, and the control unit changes the assist gas supplied to the injection unit based on the cutting speed. Claim 2 A cutter according to claim 1, wherein the control unit supplies the first gas from the switching unit to the injection unit when the cutting speed is the first speed, and supplies the second gas from the switching unit to the injection unit when the cutting speed is the second speed. Claim 3 A cutting method for cutting a workpiece by injecting a laser and an assist gas into the workpiece, wherein, based on the cutting speed of cutting the workpiece, the assist gas injected into the workpiece is converted into a first gas or a second gas having a higher nitrogen concentration than the first gas. Claim 4 A cutting method according to paragraph 3, wherein when the cutting speed is a first speed which is a fast speed range among the cutting speeds, the first gas is injected into the workpiece, and when the cutting speed is a second speed which is slower than the first speed, the second gas is injected into the workpiece. Claim 5 A cutting machine comprising: an injection unit capable of cutting a workpiece by injecting a laser and an assist gas into the workpiece; a switching unit capable of switching the assist gas supplied to the injection unit, wherein a first gas and a second gas having a higher nitrogen concentration than the first gas are supplied to the injection unit as the assist gas; and a control unit capable of changing the assist gas supplied to the injection unit by the switching unit by controlling the switching unit, wherein the control unit changes the assist gas supplied to the injection unit based on the cutting area in which the injection unit cuts the workpiece. Claim 6 A cutter according to claim 5, wherein the control unit supplies the first gas from the conversion unit to the injection unit when the cutting area is the first area, which is the larger area of ​​the cutting areas, and supplies the second gas from the conversion unit to the injection unit when the cutting area is the second area, which is the smaller area of ​​the cutting area. Claim 7 A cutting method for cutting a workpiece by injecting a laser and an assist gas into the workpiece, wherein, based on the cutting area of ​​the workpiece, the assist gas injected into the workpiece is converted into a first gas or a second gas having a higher nitrogen concentration than the first gas. Claim 8 A cutting method according to claim 7, wherein when the cutting area is a first area which is a larger area region among the cutting areas, the first gas is injected into the workpiece, and when the cutting area is a second area which is smaller than the first area, the second gas is injected into the workpiece.

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