Cutter, cutting method, and program

Abstract

To provide a cutter, a cutting method, and a program capable of reducing a minimum groove width in cutting of a back groove.SOLUTION: A cutter 1 includes: a plasma torch 10 that includes an electrode 11 and jets plasma arc in an axial direction to cut a material to be cut W; a power source part 30 that supplies power to the plasma torch 10; and a control part 40 that controls the plasma torch 10. The control part 40 causes the plasma torch 10 to jet the plasma arc to cut the material to be cut W in a first process, causes the plasma torch 10 to cut the material to be cut W while inclining the plasma torch 10 in a first inclination direction such that an absolute value of an inclination angle formed by the axial direction of the plasma torch 10 and the material to be cut becomes larger than an absolute value of an inclination angle of the first process, in a second process, and causes the plasma torch 10 inclined in a second inclination direction to cut the material to be cut W in a third process, to form an inverted-V-shaped groove inclined in a direction away from a reference cutting axis as becoming close to a rear surface Wb of the material to be cut W in a cross section perpendicular to a cutting path.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cutting machine, a cutting method, and a program. [Background technology]

[0002] BACKGROUND ART Conventionally, plasma cutting machines that cut materials such as steel plates by plasma cutting are known (for example, Patent Document 1).

[0003] A plasma cutting machine applies a voltage between an electrode in a plasma torch and the material to be cut, and generates a plasma arc by flowing a working gas such as oxygen gas, and the plasma arc melts and cuts the material to be cut.

[0004] When cutting holes using plasma cutting, groove cutting is performed so that the cut surface of the material is inclined obliquely relative to the plate thickness direction. Groove cutting is performed, for example, to make the material easier to weld after cutting.

[0005] There are two types of groove cutting: V-groove cutting, which creates a V-shaped groove cross section on the material being cut. There is also back groove cutting, which cuts the material so that the groove width on the back side is wider than the groove width on the front side. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 7-88654 Summary of the Invention [Problem to be solved by the invention]

[0007] In groove cutting such as back groove cutting, it is required to narrow the minimum groove width in order to reduce the amount of welding material and welding time required for welding after cutting.

[0008] In view of the above circumstances, the present invention aims to provide a cutting machine, a cutting method, and a program that can further narrow the minimum groove width in back groove cutting. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention proposes the following means. The cutting machine of the present invention comprises a plasma torch having an electrode and configured to cut a workpiece by spraying a plasma arc in an axial direction, a power supply unit that supplies power to the plasma torch, and a control unit that controls the plasma torch. In a first step of cutting the workpiece, the control unit sprays the plasma arc from the plasma torch onto the surface of the workpiece to cut the workpiece, and in a second step, the control unit cuts the workpiece with the plasma torch tilted in a first tilt direction so that the absolute value of the tilt angle, which is the angle between the axial direction of the plasma torch and the thickness direction of the workpiece, is greater than the absolute value of the tilt angle in the first step, and in a third step, the control unit cuts the workpiece with the plasma torch tilted in a second tilt direction opposite to the first tilt direction, and forms an inverted V-shaped groove that slopes away from the reference cutting axis, which is the axis of the plasma torch in the first step, as it approaches the back surface of the workpiece in a cross section perpendicular to the cutting path.

[0010] The cutting method of the present invention is a cutting method for cutting a workpiece using a cutting machine equipped with a plasma torch having an electrode and spraying a plasma arc in an axial direction to cut the workpiece, and a power supply unit that supplies power to the plasma torch. The cutting method includes: a first step of spraying the plasma arc from the plasma torch onto the surface of the workpiece to cut the workpiece; a second step of cutting the workpiece with the plasma torch tilted in a first tilt direction so that the absolute value of the tilt angle, which is the angle between the axial direction of the plasma torch and the thickness direction of the workpiece, is greater than the absolute value of the tilt angle in the first step; and a third step of cutting the workpiece with the plasma torch tilted in a second tilt direction opposite to the first tilt direction. In a cross section perpendicular to the cutting path, an inverted V-shaped groove is formed that slopes away from the reference cutting axis, which is the axis of the plasma torch in the first step, as it approaches the back surface of the workpiece.

[0011] The program of the present invention is a program for controlling a cutting machine that includes a plasma torch having an electrode and that cuts a material to be cut by spraying a plasma arc in an axial direction, and a power supply unit that supplies power to the plasma torch. In a first step of cutting the material to be cut, the plasma arc is sprayed from the plasma torch onto the surface of the material to be cut, thereby cutting the material to be cut. In a second step, the plasma torch is tilted in a first tilt direction so that the absolute value of the tilt angle, which is the angle between the axial direction of the plasma torch and the thickness direction of the material to be cut, is greater than the absolute value of the tilt angle in the first step. In a third step, the plasma torch is tilted in a second tilt direction opposite to the first tilt direction, thereby forming an inverted V-shaped groove that tilts away from the reference cutting axis, which is the axis of the plasma torch in the first step, as it approaches the back surface of the material to be cut in a cross section perpendicular to the cutting path. [Effects of the Invention]

[0012] According to the cutting machine, cutting method, and program of the present invention, it is possible to provide a cutting machine, cutting method, and program that can further narrow the minimum groove width in back groove cutting. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a diagram schematically illustrating a cutting machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a first step of the cutting method according to the present embodiment. [Figure 3] FIG. 10 is a diagram showing a second step of the cutting method. [Figure 4] FIG. 10 is a diagram showing a third step of the cutting method. [Figure 5] FIG. 1 is a diagram showing a first step of a conventional cutting method. [Figure 6] FIG. 10 is a diagram showing a second step of the conventional cutting method. [Figure 7] 1 is a photograph showing the minimum groove width of Example 1. [Figure 8] 1 is a photograph showing the minimum groove width of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] FIG. 1 is a diagram schematically showing a cutting machine 1 according to this embodiment. FIG. 2 is a diagram showing a first step of a cutting method for cutting a workpiece W by the cutting machine 1. As shown in FIG.

[0016] In this embodiment, as shown in FIG. 1, the X-axis, Y-axis, and Z-axis are perpendicular to each other, and the X-axis is defined as the horizontal left-right direction, the Y-axis is defined as the horizontal front-back direction, and the Z-axis is defined as the vertical up-down direction.

[0017] The cutting machine 1 includes a plasma torch 10, a working gas supply unit 20, a power supply unit 30, and a control unit 40.

[0018] In this embodiment, the cutting machine 1 is a plasma cutting machine capable of cutting a workpiece W placed vertically below the plasma torch 10.

[0019] In the following description, the side of the plasma torch 10 in the direction in which the axis O of the plasma torch 10 extends (axial direction) where the material to be cut is provided will be referred to as the "tip side" and the opposite side will be referred to as the "base side".

[0020] The plasma torch 10 includes an electrode 11, a nozzle portion 12, a working gas passage 13, and an electrode material 14.

[0021] 1, the electrode 11 is provided in the internal space of the nozzle portion 12. The electrode 11 has a cylindrical outer shape with a bottom and centered on an axis O. The electrode 11 has a bottom on the tip side in the axial direction of the plasma torch 10.

[0022] The electrode 11 is formed of a material with a relatively high conductivity, such as copper. Cooling water for cooling the electrode 11 can be circulated in the internal space of the electrode 11, for example.

[0023] The nozzle portion 12 has a cylindrical outer shape centered on an axis O. The tip portion of the nozzle portion 12 has a hollow truncated cone shape that tapers toward the tip.

[0024] The working gas flow path 13 is formed in the internal space of the nozzle portion 12 between the outer peripheral surface of the electrode 11 and the inner peripheral surface of the nozzle portion 12. A nozzle hole 12a communicating with the working gas flow path 13 is formed at the tip of the nozzle portion 12.

[0025] The electrode material 14 is provided on the tip side of the electrode 11 and is made of a material such as hafnium.

[0026] The working gas supply unit 20 is connected to the base end side of the working gas flow path 13 via a hose or the like, and supplies a working gas such as oxygen gas to the working gas flow path 13. The working gas supplied from the working gas supply unit 20 to the working gas flow path 13 is sprayed toward the tip side of the plasma torch 10 from the nozzle hole 12a that communicates with the working gas flow path 13.

[0027] The nozzle section 12 may be configured with two or more nozzle layers, and may have an auxiliary fluid flow path for flowing an auxiliary fluid around the working gas. Examples of the auxiliary fluid include air, oxygen, nitrogen, mixed gases mainly containing oxygen, and water.

[0028] The power supply unit 30 supplies current to the electrode 11 of the plasma torch 10 and the workpiece W to generate a plasma arc P between the electrode 11 and the workpiece W. The power supply unit 30 is electrically connected to both the electrode 11 and the workpiece W. The power supply unit 30 is also electrically connected to the nozzle unit 12 of the plasma torch 10.

[0029] The power supply unit 30 uses power supplied from a commercial power source, for example, to supply current to the plasma torch 10 and the workpiece W. The current supplied from the power supply unit 30 may be either direct current or alternating current.

[0030] A predetermined voltage is applied between the electrode 11 and the workpiece W by the power supply unit 30 to generate a plasma arc P, which can be sprayed onto the workpiece W from the nozzle hole 12 a of the plasma torch 10 .

[0031] The control unit 40 controls a part or the whole of the cutting machine 1 .

[0032] The control unit 40 changes the position and angle of the plasma torch 10 by controlling, for example, a support (not shown) connected to the base end side of the nozzle unit 12 .

[0033] For example, the control unit 40 changes the angle of the plasma torch 10 to change the angle between the axis O of the plasma torch 10 and the thickness direction of the workpiece W. The control unit 40 also changes the position of the plasma torch 10 in the X-axis direction or the Y-axis direction, thereby moving the plasma torch 10 in the cutting direction of the workpiece W. The control unit 40 may also move the position of the plasma torch 10 in the Z-axis direction so as to follow the surface position of the workpiece W.

[0034] The control unit 40 may control the working gas supply unit 20 to change the flow rate of the working gas supplied from the working gas supply unit 20 to the working gas flow path 13. The control unit 40 may change the flow rate of the auxiliary fluid.

[0035] The control unit 40 may control the power supply unit 30 to change the current value and voltage supplied from the power supply unit 30 to the plasma torch 10 and the workpiece W to be cut.

[0036] The control unit 40 is, for example, a programmable device (computer) equipped with a processor, a memory, a storage unit, etc. Each function of the control unit 40 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 a program memory. However, all or part of these functions may be realized by hardware (e.g., circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a PLD (Programmable Logic Device). Furthermore, all or part of the above functions may be realized by a combination of software and hardware. The storage unit is realized by a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), a ROM (Read-Only Memory), a RAM (Random Access Memory), etc.

[0037] Next, a cutting method using the cutting machine 1 will be described.

[0038] The cutting method described below is a cutting method in which a back groove is cut on a workpiece W to form a groove in the workpiece W. In the following description, the groove formed by the back groove cutting is also referred to as an "inverted V-shaped groove."

[0039] (first step) First, the control unit 40 performs the first step of the cutting method using the cutting machine 1. In the first step, as shown in Fig. 2, the control unit 40 causes a plasma arc P to be sprayed from the nozzle hole 12a of the plasma torch 10 onto the processing location C of the workpiece W, and causes the plasma arc P to cut the workpiece W.

[0040] When the workpiece W is cut by the plasma arc P, the working gas supply unit 20 supplies working gas to the periphery of the electrode 11 of the plasma torch 10 through the working gas passage 13 .

[0041] Furthermore, a voltage is applied between the electrode 11 and the nozzle portion 12 by the power supply portion 30 , thereby generating a pilot arc from the electrode 11 within the nozzle portion 12 .

[0042] By continuing to supply the working gas in this state, the working gas that has been plasmatized in the nozzle section 12 by the pilot arc is sprayed from the nozzle hole 12a, and a voltage is applied between the electrode 11 and the workpiece W by the power supply section 30 to form a plasma arc (main arc) P.

[0043] Furthermore, the voltage applied between the electrode 11 and the nozzle portion 12 is stopped to stop the pilot arc.

[0044] The workpiece W is melted by the thermal energy of the plasma arc P, and the molten material is expelled by the jet energy of the plasma arc P. In this way, the cutting machine 1 forms a groove penetrating the workpiece W, and performs plasma cutting.

[0045] In the first step, the control unit 40 positions the plasma torch 10 within a range in which the angle formed between the axis O of the plasma torch 10 and the thickness direction of the workpiece W is relatively small. In this embodiment, the thickness direction of the workpiece W coincides with the Z-axis direction. Also, in this embodiment, the axis O of the plasma torch 10 in the first step coincides with the thickness direction of the workpiece W.

[0046] 2, in the first step, the plasma arc P penetrates from the front surface Wa to the back surface Wb of the workpiece W. The front surface Wa of the workpiece W is the surface facing the plasma torch 10 in the thickness direction of the workpiece W. The back surface Wb is the surface opposite to the front surface Wa in the thickness direction of the workpiece W.

[0047] In this embodiment, the front surface Wa of the workpiece W is the vertically upper surface, and the back surface Wb is the vertically lower surface.

[0048] By cutting the workpiece W with the plasma arc P in the first step, a first cut surface S1 and a second cut surface S2 are formed in the workpiece W, as shown in Fig. 2. The cross section shown in Fig. 2 is perpendicular to the cutting path along which the cutting machine 1 cuts the workpiece W.

[0049] In the following description, the end of the first cut surface S1 on the surface Wa side will be referred to as a first cut edge W1, and the end of the second cut surface S2 on the surface Wa side will be referred to as a second cut edge W2.

[0050] In the first step, the control unit 40 moves the plasma torch 10 in the X-axis direction or the Y-axis direction, and causes the plasma torch 10 moved along a predetermined cutting path to cut the workpiece W.

[0051] (Second process) Next, the control unit 40 performs the second step of the cutting method using the cutting machine 1. FIG. 3 is a diagram showing a second step of the cutting method for cutting the workpiece W by the cutting machine 1. As shown in FIG.

[0052] The reference cutting axis V shown in Fig. 3 is an axis line that coincides with the axis O of the plasma torch 10 in the first step shown in Fig. 2. In this embodiment, the reference cutting axis V extends in the thickness direction (Z-axis direction) of the workpiece W.

[0053] In the second step, as shown in FIG. 3, the control unit 40 injects a plasma arc P from the plasma torch 10 tilted so that the absolute value of the tilt angle (first tilt angle θ1), which is the angle between the axis O of the plasma torch 10 and the reference cutting axis V, is greater than the absolute value of the tilt angle (reference tilt angle) in the first step, thereby cutting the workpiece W.

[0054] The first tilt angle θ1 in the second step is the angle formed between the axial direction of the plasma torch 10 and the thickness direction of the workpiece W to be cut.

[0055] As described above, in this embodiment, the axis O of the plasma torch 10 in the first step shown in Fig. 2 extends in the thickness direction of the workpiece W. The reference cutting axis V coincides with the thickness direction of the workpiece W. Therefore, the reference tilt angle in the first step is 0 degrees.

[0056] In the second step, the control unit 40 tilts the plasma torch 10 toward the first cut surface S1 side, as shown in Fig. 3. The direction in which the plasma torch 10 is tilted in the second step is referred to as a first tilt direction D1.

[0057] The second cut surface S2 formed in the first step is cut by ejecting a plasma arc from the plasma torch 10 tilted in the first tilt direction D1.

[0058] The cross section shown in Fig. 3 is a cross section perpendicular to the cutting path along which the cutting machine 1 cuts the workpiece W. As shown in Fig. 3, the second cut surface S2 cut in the second step is an inclined surface that inclines in a direction away from the reference cutting axis V as it approaches the back surface Wb in the cross section perpendicular to the cutting path.

[0059] In the second step, the plasma torch 10 sprays a plasma arc P onto the processing location C cut in the first step. Therefore, the distance in the X-axis direction between the first cut end W1 and the second cut end W2 is approximately the same in the first step and the second step.

[0060] In the second step, the control unit 40 moves the plasma torch 10 in the X-axis direction or the Y-axis direction, and causes the plasma torch 10 moved along a predetermined cutting path to cut the workpiece W.

[0061] The plasma torch 10 moves along a predetermined cutting path while maintaining a posture inclined in the first inclination direction D1.

[0062] In this embodiment, the cutting path along which the plasma torch 10 moves in the second step is the same as the cutting path in the first step, but the cutting path may be adjusted using cutting width correction or the like.

[0063] (Third step) Next, the control unit 40 performs the third step of the cutting method using the cutting machine 1. FIG. 4 is a diagram showing a third step of the cutting method for cutting the workpiece W by the cutting machine 1. As shown in FIG.

[0064] In the third step, as shown in FIG. 4, the control unit 40 injects a plasma arc P from the plasma torch 10 tilted so that the tilt angle (second tilt angle θ2) of the plasma torch 10 is larger than the reference tilt angle in the first step, thereby cutting the workpiece W.

[0065] The second tilt angle θ2 in the third step is the angle between the axial direction of the plasma torch 10 and the thickness direction of the workpiece W. In this embodiment, the second tilt angle θ2 in the third step is equal to the first tilt angle θ1 in the second step.

[0066] In the third step, the control unit 40 tilts the plasma torch 10 toward the second cut surface S2, as shown in Fig. 4. The direction in which the plasma torch 10 is tilted in the third step is referred to as a second tilt direction D2. The second tilt direction D2 is opposite to the first tilt direction D1.

[0067] The first cut surface S1 formed in the first step is cut by ejecting a plasma arc from the plasma torch 10 tilted in the second tilt direction D2.

[0068] The cross section shown in Fig. 4 is a cross section perpendicular to the cutting path along which the cutting machine 1 cuts the workpiece W. As shown in Fig. 4, the first cut surface S1 cut in the third step is an inclined surface that is inclined in a direction away from the reference cutting axis V as it approaches the back surface Wb in the cross section perpendicular to the cutting path.

[0069] In the third step, the plasma torch 10 sprays a plasma arc P onto the processing area C cut in the first and second steps. Therefore, the distance in the X-axis direction between the first cut end W1 and the second cut end W2 is approximately the same in the second and third steps.

[0070] In the third step, the control unit 40 moves the plasma torch 10 in the X-axis direction or the Y-axis direction, and causes the plasma torch 10 moved along a predetermined cutting path to cut the workpiece W.

[0071] The plasma torch 10 moves along a predetermined cutting path while maintaining a posture inclined in the second inclination direction D2.

[0072] In this embodiment, the cutting path along which the plasma torch 10 moves in the third step is the same as the cutting path in the first step, but the cutting path may be adjusted using cutting width correction or the like.

[0073] By carrying out the second and third steps, an inverted V-shaped groove is formed in the workpiece W. As shown in Fig. 4, the inverted V-shaped groove is a V-shaped groove inclined in a direction away from the reference cutting axis V as the first cutting surface S1 and the second cutting surface S2 approach the back surface Wb side.

[0074] In the inverted V-shaped groove formed in the workpiece W, the width of the groove on the front surface Wa side is narrower than the width of the groove on the back surface Wb side. In the following description, the width of the inverted V-shaped groove on the front surface Wa side is referred to as the minimum groove width L1. The minimum groove width L1 is the distance in the X-axis direction between the first cutting edge W1 and the second cutting edge W2.

[0075] Here, a conventional cutting method using a back groove cutting will be described.

[0076] Fig. 5 is a diagram showing a first step of a conventional cutting method for rear groove cutting, and Fig. 6 is a diagram showing a second step of a conventional cutting method for rear groove cutting.

[0077] In the first step of conventional back groove cutting, as shown in Figure 5, the plasma torch 10 is positioned so that its axial direction is tilted from the thickness direction of the workpiece W, and a plasma arc P is sprayed to cut the workpiece W.

[0078] Therefore, in the first step of conventional back groove cutting, a cutting groove is formed in the workpiece W that extends in a direction inclined from the plate thickness direction of the workpiece W.

[0079] Next, in the second step of conventional back groove cutting, as shown in Fig. 6, the plasma torch 10 is positioned so that its axial direction is tilted from the thickness direction of the workpiece W, and a plasma arc P is sprayed to cut the workpiece W. At this time, the plasma torch 10 is tilted in the opposite direction to the direction in which it was tilted in the first step.

[0080] In conventional back groove cutting, an inverted V-shaped groove is formed in a workpiece W by carrying out two steps shown in FIGS.

[0081] In the cutting method using the cutting machine 1 of this embodiment, as described above, an inverted V-shaped groove is formed in the workpiece W by carrying out the three steps (first step to third step) shown in Figures 2 to 4.

[0082] The back groove cutting by the cutting machine 1 of this embodiment further includes a first step shown in FIG. 2 in addition to the conventional back groove cutting.

[0083] The first step of this embodiment is a step of cutting the workpiece W using a plasma torch 10 positioned so that the absolute value of the angle (tilt angle) between the axial direction of the plasma torch 10 and the thickness direction of the workpiece W is smaller than the absolute values ​​of the tilt angles in the second and third steps.

[0084] In the second step of back groove cutting by the cutting machine 1 of this embodiment, the plasma arc P is sprayed onto the cut surface formed in the first step, so the cutting distance is shorter than in the first step of conventional back groove cutting. Here, the cutting distance refers to the distance of the path traveled by the plasma arc P sprayed onto the front surface Wa of the workpiece W or the cut surface formed in the previous step until it penetrates to the back surface Wb.

[0085] Furthermore, in the second step of this embodiment, the groove cut in the first step serves as a path for discharging slag, making it easier to discharge slag than in the first step of conventional back groove cutting.

[0086] Therefore, in the second step of this embodiment, the cutting speed can be made faster than in the first step of conventional back groove cutting. In conventional back groove cutting, heat tends to concentrate on the second cut edge W2, which has an acute angle, increasing the amount of melting at the second cut edge W2. However, in this embodiment, the heat concentration on the second cut edge W2, which has an acute angle, is reduced by increasing the cutting speed, thereby reducing the amount of melting at the second cut edge W2.

[0087] The same is true for the third step of this embodiment, which allows the cutting speed to be faster than in the second step of conventional back groove cutting, thereby reducing the amount of melting of the first cut edge W1, which has an acute angle.

[0088] In this way, the cutting machine 1 of this embodiment can form an inverted V-shaped groove with a minimum groove width L1 that is smaller than the minimum groove width L2 of an inverted V-shaped groove formed by a conventional plasma cutting machine.

[0089] The cutting machine 1 of this embodiment includes a plasma torch 10 having an electrode 11 and spraying a plasma arc P in the axial direction to cut the workpiece W, a power supply unit 30 that supplies power to the plasma torch 10, and a control unit 40 that controls the plasma torch 10.

[0090] In the first step of cutting the workpiece W, the control unit 40 cuts the workpiece W by injecting a plasma arc P from the plasma torch 10 onto the surface Wa of the workpiece W.

[0091] In addition, in the second step, the control unit 40 causes the plasma torch 10 tilted in the first tilt direction D1 to cut the workpiece W so that the absolute value of the tilt angle (first tilt angle θ1), which is the angle between the axial direction of the plasma torch 10 and the thickness direction of the workpiece W, is greater than the absolute value of the tilt angle (reference tilt angle) in the first step.

[0092] In addition, in the third step, the control unit 40 causes the plasma torch 10 tilted in a second tilt direction D2 opposite to the first tilt direction D1 to cut the workpiece W.

[0093] The cutting machine 1 forms an inverted V-shaped groove that slopes away from the reference cutting axis V as it approaches the back surface Wb of the workpiece W in a cross section perpendicular to the cutting path along which the workpiece W is cut by the plasma torch 10.

[0094] The inverted V-shaped groove formed by the cutting machine 1 is a groove in which the first cutting surface S1 and the second cutting surface S2 formed on both sides of the reference cutting axis V face each other in the plate surface direction of the workpiece W (here, the X-axis direction), as shown in Figure 4.

[0095] The cutting method of this embodiment is a cutting method for cutting a workpiece W using a cutting machine 1, and includes a first step of spraying a plasma arc P from a plasma torch 10 onto the surface Wa of the workpiece W to cut the workpiece W; a second step of cutting the workpiece W with the plasma torch 10 tilted in a first tilt direction D1 so that the absolute value of the tilt angle (first tilt angle θ1), which is the angle between the axial direction of the plasma torch 10 and the thickness direction of the workpiece W, is greater than the absolute value of the tilt angle (reference tilt angle) of the first step; and a third step of cutting the workpiece W with the plasma torch 10 tilted in a second tilt direction D2 opposite to the first tilt direction D1, and forms an inverted V-shaped groove inclined away from the reference cutting axis V as it approaches the back surface Wb of the workpiece W in a cross section perpendicular to the cutting path.

[0096] The program of this embodiment is a program for controlling a cutting machine 1, and in a first step of cutting the workpiece W, a plasma arc P is sprayed from the plasma torch 10 onto the surface Wa of the workpiece W to cut the workpiece W; in a second step, the workpiece W is cut with the plasma torch tilted in a first tilt direction D1 so that the absolute value of the tilt angle (first tilt angle θ1), which is the angle between the axial direction of the plasma torch 10 and the thickness direction of the workpiece W, is greater than the absolute value of the tilt angle (reference tilt angle) in the first step; and in a third step, the workpiece W is cut with the plasma torch 10 tilted in a second tilt direction D2 opposite to the first tilt direction D1, so that an inverted V-shaped groove is formed in a cross section perpendicular to the cutting path that tilts away from the reference cutting axis V as it approaches the back surface Wb of the workpiece W.

[0097] As a result, the cutting machine 1, cutting method, and program of the present embodiment can provide the cutting machine 1, cutting method, and program that can further narrow the minimum groove width L1 in back groove cutting.

[0098] Although one embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the present invention. Furthermore, the components shown in the above-described embodiment and the following modified examples can be appropriately combined to form a configuration.

[0099] (Variation 1) In the above embodiment, the control unit 40 positions the plasma torch 10 in the first step so that the axis O of the plasma torch 10 extends in the Z-axis direction, but the aspect of the control unit is not limited to this.

[0100] In the first step, the control unit may cut the workpiece by positioning the plasma torch so that the axis of the plasma torch extends in a direction different from the Z-axis direction.

[0101] Even if the axis of the plasma torch in the first step extends in a direction different from the Z-axis direction, the minimum groove width can be made narrower than in conventional back groove cutting by making the reference inclination angle, which is the angle between the axis of the plasma torch in the first step and the thickness direction of the workpiece, smaller than the first inclination angle θ1 in the second step and the second inclination angle θ2 in the third step.

[0102] (Variation 2) In the above embodiment, the first tilt angle θ1 in the second step and the second tilt angle θ2 in the third step are equal, but the first tilt angle and the second tilt angle are not limited to this. The first tilt angle in the second step and the second tilt angle in the third step may be different angles.

[0103] (Variation 3) In the above embodiment, the control unit changes the angle of the plasma torch 10 in the first step, the second step, and the third step, but the aspect of the control unit is not limited to this.

[0104] The control unit may change cutting conditions such as the current value supplied from the power supply unit, the flow rate of the working gas supplied from the working gas supply unit, the flow rate of the auxiliary fluid, the cutting height, or the cutting width correction value in the first, second, and third steps.

[0105] For example, the control unit may increase the cutting speed in the first step to a level at which blow-up does not occur, and may increase the cutting speed in the second and third steps within a range that satisfies cutting quality.

[0106] The control unit may also set arbitrary cutting conditions depending on the thickness and material of the workpiece W. For example, information on various thicknesses and materials of the workpiece W (workpiece information) and cutting conditions corresponding to each piece of workpiece information may be stored in a memory unit of the control unit. In this case, the control unit may control the plasma torch, the working gas supply unit, or the power supply unit based on the cutting conditions stored in the memory unit.

[0107] (Variation 4) In the above embodiment, the control unit 40 performs the first, second, and third steps in this order to cut the workpiece W, but the control unit is not limited to this. The control unit may perform another step between the first and second steps or between the second and third steps.

[0108] For example, the control unit may insert an arc-extinguishing sequence or an arc-activating sequence between the first step and the second step, or between the second step and the third step. Also, the control unit may execute the third step after the first step, and the second step after the third step.

[0109] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

[0110] Example 1 The cutting machine 1 of the above embodiment performed the first, second and third steps shown in FIGS. 2, 3 and 4 to plasma cut the workpiece W to form an inverted V-shaped groove.

[0111] The thickness of the workpiece W was 22 mm. The material of the workpiece W was a zinc-rich primer material (SS400).

[0112] (Comparative Example 1) The first and second steps of conventional back groove cutting shown in Figures 5 and 6 were carried out, and the material to be cut was plasma cut to form an inverted V-shaped groove.

[0113] The thickness and material of the workpiece were the same as those in the example.

[0114] (Experiment 1) The minimum groove width of the inverted V-shaped grooves in Example 1 and Comparative Example 1 was measured.

[0115] (Experimental results) 7 is a photograph showing the minimum groove width L1 of Example 1. FIG. 8 is a photograph showing the minimum groove width L2 of Comparative Example 1.

[0116] The results of Experiment 1 are shown in Table 1.

[0117] The minimum groove width L1 of Example 1, in which the first, second and third steps were performed using the cutting machine 1 of the above embodiment, was 6.0 mm.

[0118] The minimum groove width L2 of Comparative Example 1, which was subjected to the first and second steps of conventional back V groove cutting, was 7.5 mm, which was wider than the minimum groove width L1 of Example 1.

[0119] [Table 1] [Explanation of symbols]

[0120] 1 cutting machine 10 Plasma Torch 11 electrodes 30 Power supply section 40 Control Unit O Plasma torch shaft V Reference cutting axis C. Processing area W Material to be cut Wa Surface of the material to be cut Wb Back side of the workpiece P Plasma Arc θ1 First tilt angle (tilt angle) θ2 Second tilt angle (tilt angle) D1 First tilt direction D2 Second tilt direction

Claims

1. a plasma torch having an electrode and configured to cut a workpiece by ejecting a plasma arc in an axial direction; a power supply unit that supplies power to the plasma torch; a control unit for controlling the plasma torch; Equipped with The control unit In a first step of cutting the workpiece, the plasma arc is sprayed from the plasma torch onto the surface of the workpiece to cut the workpiece, In a second step, the workpiece is cut by the plasma torch tilted in a first tilt direction so that the absolute value of the tilt angle, which is the angle between the axial direction of the plasma torch and the thickness direction of the workpiece, is larger than the absolute value of the tilt angle in the first step; In a third step, the workpiece is cut by the plasma torch tilted in a second tilt direction opposite to the first tilt direction, In a cross section perpendicular to the cutting path, an inverted V-shaped groove is formed which is inclined in a direction away from a reference cutting axis, which is the axis of the plasma torch in the first step, as it approaches the back surface of the workpiece. cutting machine.

2. The reference cutting axis substantially coincides with the plate thickness direction.

2. The cutting machine according to claim 1.

3. In the second step and the third step, the plasma torch sprays the plasma arc onto approximately the same location on the surface of the workpiece that was cut in the first step. The cutting machine according to claim 1 or 2.

4. A cutting method for cutting a workpiece using a cutting machine including a plasma torch having an electrode and cutting the workpiece by spraying a plasma arc in an axial direction, and a power supply unit supplying power to the plasma torch, a first step of cutting the workpiece by spraying the plasma arc from the plasma torch onto the surface of the workpiece; a second step of cutting the workpiece with the plasma torch tilted in a first tilt direction so that the absolute value of the tilt angle, which is the angle between the axial direction of the plasma torch and the thickness direction of the workpiece, is larger than the absolute value of the tilt angle in the first step; a third step of cutting the workpiece with the plasma torch tilted in a second tilt direction opposite to the first tilt direction; Equipped with In a cross section perpendicular to the cutting path, an inverted V-shaped groove is formed which is inclined in a direction away from a reference cutting axis, which is the axis of the plasma torch in the first step, as it approaches the back surface of the workpiece. Cutting method.

5. The reference cutting axis substantially coincides with the plate thickness direction. The cutting method according to claim 4.

6. In the second step and the third step, the plasma arc is sprayed onto substantially the same location on the surface of the workpiece as that cut in the first step. The cutting method according to claim 4 or 5.

7. A program for controlling a cutting machine including a plasma torch having an electrode and cutting a workpiece by spraying a plasma arc in an axial direction, and a power supply unit supplying power to the plasma torch, In a first step of cutting the workpiece, the plasma arc is sprayed from the plasma torch onto the surface of the workpiece to cut the workpiece, In a second step, the workpiece is cut by the plasma torch tilted in a first tilt direction so that the absolute value of the tilt angle, which is the angle between the axial direction of the plasma torch and the thickness direction of the workpiece, is larger than the absolute value of the tilt angle in the first step; In a third step, the workpiece is cut by the plasma torch tilted in a second tilt direction opposite to the first tilt direction, In a cross section perpendicular to the cutting path, an inverted V-shaped groove is formed which is inclined in a direction away from a reference cutting axis, which is the axis of the plasma torch in the first step, as it approaches the back surface of the workpiece. program.

8. The reference cutting axis substantially coincides with the plate thickness direction. The program according to claim 7.

9. In the second step and the third step, the plasma arc is sprayed onto substantially the same location on the surface of the workpiece as that cut in the first step. The program according to claim 7 or 8.

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