JP2006255773A - Thermal cutting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal cutting device where both of plasma cutting and gas cutting can be performed with one torch. <P>SOLUTION: The thermal cutting device capable of performing both of plasma cutting and gas cutting is provided with: a torch body (100); a means (13) of at least feeding combustion gas and oxygen gas to the torch body; a plasma attachment (160) fittable to the torch body freely attachably and detachably and making plasma cutting possible when being fitted; and gas attachments (140, 150) which are detachably fittable to the torch body and enables gas cutting when being fitted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention provides a thermal cutting apparatus capable of performing both plasma cutting and gas cutting.

Related.

Conventionally, a plasma torch for performing plasma cutting and a gas torch for performing gas cutting are known (for example, Patent Documents 1 and 2).
JP 2000-326072 A JP 2000-88216 A

  In addition, in a conventional thermal cutting apparatus that controls plasma cutting and gas cutting with a single controller, a plasma torch and a gas torch are provided separately, and either one is selectively used. When cutting a flat workpiece (material to be cut), the XY table on which the workpiece is placed has a Z-axis as an axis for copying the height to keep the distance between the workpiece and the torch constant. A plasma torch and a gas torch are mounted side by side. In this case, a gas pipe is connected to each torch from each gas supply source such as a plasma gas and a cutting gas for gas cutting. A cooling water hose is also connected.

  For this reason, in a conventional thermal cutting apparatus capable of performing plasma cutting and gas cutting, it is necessary to install two torches at a distance in order to mount the plasma torch and the gas torch side by side and attach them to a moving mechanism that moves the torch. For this reason, the torch mounting part becomes large, and as a result, the size of the XY table becomes larger by the offset of the two torches than when only one of the gas torch or the plasma torch is used.

  In addition, when the Z-axis of the height copy is attached to each of the plasma torch and the gas torch, or when they are attached to the same Z-axis, the plasma torch is changed in the height direction (Z direction) when switching between the two torches. A mechanism for changing the height relationship of the gas torch is required, which increases the size of the apparatus and increases the manufacturing cost.

  Furthermore, in the conventional gas torch, ignition of the preheating flame and setting of the initial height had to be performed manually.

  Therefore, an object of the present invention is to provide a thermal cutting apparatus capable of performing both plasma cutting and gas cutting with a single torch.

  Furthermore, another object of the present invention is to simplify the configuration of a thermal cutting apparatus that can perform both plasma cutting and gas cutting with a single torch.

  The thermal cutting device according to one embodiment of the present invention is a thermal cutting device capable of performing both plasma cutting and gas cutting. And, the torch body (100), the means (13) for supplying fuel gas and oxygen gas to the torch body, and can be detachably attached to the torch body, enabling plasma cutting when attached. A plasma attachment (160) and a gas attachment (140, 150) that can be detachably attached to the main body of the torch and allow gas cutting when attached.

  In a preferred embodiment, the plasma attachment and the gas attachment may be selectively attached to the tip of the torch body.

  In a preferred embodiment, the plasma attachment includes an electrode (161), a plasma nozzle (163) surrounding the tip of the electrode, and a retainer cap (166) for fixing the electrode and the plasma nozzle to the torch body. The gas attachment may have a gas cutting crater (151) and a retainer cap (155) for fixing the gas cutting crater to the torch body.

  In a preferred embodiment, the torch body has first, second, and third gas passages (111, 121, 131). When the plasma attachment is attached to the torch body, at least one of the first, second, and third gas passages of the torch body is a plasma gas passage of the plasma attachment, a secondary When the gas attachment is attached to the torch body in communication with the gas passage and the tertiary gas passage, each of the first, second and third gas passages of the torch body cuts the gas attachment. Each of the gas passage, the fuel gas passage, and the preheated oxygen passage, the other one, and the remaining one may be communicated with each other.

  In a preferred embodiment, when the plasma attachment is attached to the torch body, a high voltage circuit (51) for outputting a high voltage for generating a pilot arc, and the gas attachment is attached to the torch body. In this case, the high voltage circuit may further include a wiring that applies a high voltage in the vicinity of the gas cutting crater and generates a spark for igniting a preheating flame.

  In a preferred embodiment, a gas supply source (64 to 69) for supplying gas to the torch body is further provided. When the plasma attachment is attached to the torch body, the gas supply source is any one of oxygen or nitrogen in the first gas passage, air, propane, and a mixed gas of propane and nitrogen in the second gas passage. Alternatively, oxygen or nitrogen is supplied to the third gas passage, respectively. On the other hand, when the gas attachment is attached to the torch body, oxygen may be supplied to the first gas passage, fuel gas to the second gas passage, and oxygen to the third gas passage, respectively.

  Hereinafter, the thermal cutting device concerning one embodiment of the present invention is explained using a drawing.

  First, the schematic block diagram of the thermal cutting apparatus which concerns on this embodiment is shown in FIG.

  As will be described later, the thermal cutting apparatus 1 according to the present embodiment includes a torch 10 that can be used for both plasma cutting and gas cutting by exchanging attachments, and a power supply system 11 that supplies ignition voltage and plasma current to the torch 10. A gas system 13 for supplying a plurality of types of gases to the torch 10; a cooling water system 15 for supplying cooling water to the torch 10; and a plate-like workpiece (for example, A torch moving system 17 that moves the torch 10 in the X, Y, and Z directions with respect to the mild steel or stainless steel plate material 21 and a controller 18 that controls the systems 11, 13, 15, and 17 are provided.

  The torch 10 includes a torch body that is fixed to the torch moving system 17 for both plasma cutting and gas cutting, an attachment for plasma cutting and an attachment for gas cutting that are replaceably attached to the tip of the torch body. Have. By selectively attaching the plasma cutting attachment and the gas cutting attachment to the torch body, it is possible to perform both plasma cutting and gas cutting with one torch body.

  When performing plasma cutting, the power supply system 11 applies an ignition circuit for applying a high voltage for main arc ignition (that is, for generating a pilot arc) between the plasma nozzle and the electrode in the torch 10, and this after the main arc ignition. A plasma power supply circuit that causes a plasma current to be maintained between the electrode in the torch 10 and the workpiece 21 is provided.

  Further, when performing gas cutting, the power supply system 11 applies a high voltage for preheating flame ignition between the gas cutting crater in the torch 10 and the work 21 using the above-described ignition circuit. Therefore, automatic ignition is possible for both plasma cutting and gas cutting.

  In the case of plasma cutting, the gas system 13 supplies plasma gas, secondary gas, and tertiary gas to the torch 10, and in the case of gas cutting, the cutting oxygen gas, fuel gas, and preheated oxygen gas are supplied to the torch 10. Supply. The gas system 13 includes a plurality of types of gas sources such as an oxygen source, a nitrogen source, and a fuel gas (for example, propane, acetylene, hydrogen, etc.) source, and a combination of the plurality of types of gas from these gas sources Various gases for plasma cutting and gas cutting are produced.

  The cooling water system 15 sends the cooling water to the torch 10 and circulates the cooling water in the torch 10 at the time of both plasma cutting and gas cutting.

  The torch moving system 17 automatically controls the position of the torch 10 in the Z-axis direction during both plasma cutting and gas cutting according to the dimensions in the Z-axis direction of the plasma cutting attachment and the gas cutting attachment. . For example, the torch moving system 17 lowers the torch 10 in the Z-axis direction, detects contact between the tip of the torch 10 and the workpiece using a continuity tester, and determines the initial height of the torch.

  Next, the plasma cutting attachment for performing the torch body and plasma cutting will be described.

  FIG. 2A shows a cross-sectional structure of the torch body 100. A water conduit 101 for introducing cooling water into the electrode 161 is disposed at the central axis position of the torch body 100. An inner sleeve 102 fitted to the outer periphery of the water guide pipe 101 in a coaxial positional relationship with an outer sleeve 103 fitted to the outer periphery of the inner sleeve 102 is provided. A holder 104 for fixing the plasma cutting and gas cutting attachments is fitted to the outer periphery of the outer sleeve 103. Inside the nozzle pedestal 106, an internal space 109 into which the electrode 161, the guide 162, the plasma nozzle 163 and the like are fitted is formed.

  The inner sleeve 102 serves as a pedestal for holding a plasma cutting electrode 161 (see FIG. 2B), is made of metal, and is connected to one output terminal of the power supply system 11 shown in FIG. The The nozzle pedestal 106 is also made of metal and is connected to another output terminal of the power supply system 11. The inner sleeve 102 and the nozzle base 106 are insulated in the torch body 100.

  The outer sleeve 103 is formed with a first gas passage 111 penetrating through the wall. A plasma gas (for example, a mixed gas of 80 mol% of oxygen and 20 mol% of nitrogen in the case of oxygen plasma cutting) is introduced into the first gas passage 111 at the time of plasma cutting. Etc. will be guided. The plasma gas outlet 111 a at the tip of the first gas passage 111 is open toward the internal space 109.

  The outer sleeve 103 has a second gas passage 121 formed through the wall. A secondary gas (for example, a mixed gas having an oxygen concentration lower than the plasma gas in the case of oxygen plasma cutting) is guided to the second gas passage 121 during plasma cutting, and fuel gas is supplied during gas cutting. Led. The secondary gas outlet 121 a at the tip of the second gas passage 121 is provided on the outer surface of the outer sleeve 113.

  A third gas passage 131 is formed in the holder 104 so as to penetrate the wall. A tertiary gas (for example, a mixed gas having a higher oxygen concentration than the secondary gas or pure oxygen gas in the case of oxygen plasma cutting) is guided to the third gas passage 121 during plasma cutting. Preheated oxygen gas is introduced. The tertiary gas outlet 131a is provided at a place where the holder 104 fits with the plasma cutting attachment and the gas cutting attachment.

  FIG. 2B shows a cross-sectional view of a plasma cutting attachment 160 (hereinafter referred to as a plasma attachment) 160 that can be attached to and detached from the tip of the torch body 100.

  The plasma attachment 160 has an electrode 161 at the center axis position. A guide 162 made of an insulating material is fitted to the outer periphery of the central portion of the electrode 161 at a position coaxial with this. A cylindrical plasma nozzle 163 tapered toward the tip is fitted on the outer periphery of the guide 162.

  At the tip of the electrode 161, a heat-resistant insert 161a serving as a generation point of a plasma arc is provided. The heat-resistant insert 161a is made of a high melting point material that can withstand the high temperature of the plasma arc, for example, hafnium, zirconium, or an alloy thereof in the case of oxygen plasma cutting. A cooling water channel 161 b is formed inside the electrode 106.

  A plasma gas passage 113 is formed between the electrode 161 and the plasma nozzle 163. The plasma gas passage 113 communicates with a through hole (not shown) provided in the guide 162. This through-hole further communicates with a plasma gas passage 112 (see FIG. 3) formed when the plasma attachment 160 is attached to the torch body 100.

  A nozzle orifice 163a is formed at the tip of the plasma nozzle 163 to sufficiently squeeze the plasma arc into a jet stream and eject it forward. A flanged shield cap 164 for preventing damage to the plasma nozzle 163 due to a workpiece jumping up (not shown) is fitted to the tip of the plasma nozzle 163. Further, a secondary gas passage 123 is formed between the plasma nozzle 163 and the shield cap 164. The secondary gas passage 123 communicates with the opening 164a of the shield cap 164 disposed in front of the nozzle orifice 163a.

  The plasma attachment 160 has a retainer cap 166 for detachably attaching these structures to the torch body 100 outside the structures of the electrode 161, the guide 162, the plasma nozzle 163, and the like. The retainer cap 166 serves not only as a retainer but also as an outer shell of the plasma attachment 160. The hook 166a formed at the tip of the retainer cap 166 engages with the outer periphery of the shield cap 164.

  The retainer cap 166 is formed with a secondary gas passage 122 that penetrates through the wall. A secondary gas inlet 122 a at the rear end of the secondary gas passage 122 is provided at a position where the secondary gas inlet 122 a is connected to the second gas outlet 121 a of the torch body 100 when the plasma attachment 160 is attached to the torch body 100. The secondary gas outlet 122b at the tip of the secondary gas passage 122 opens at a position where the retainer cap 166 engages with the shield cap 164, and communicates with the secondary gas passage 123 inside the shield cap 164 described above. .

  Further, the retainer cap 166 is formed with a tertiary gas passage 133 penetrating the inside of the wall. The tertiary gas inlet 133a at the rear end of the tertiary gas passage 133 is formed in front of the third gas outlet 131a described above when the plasma attachment 160 is attached to the torch body 100 (FIG. 3). Open). The tertiary gas outlet 133 b at the tip of the tertiary gas passage 133 is open toward the outer surface of the shield cap 164 at the tip of the retainer cap 166.

  When the plasma attachment 160 is attached to the torch main body 100, the retainer cap 166 accommodates the components 161, 162, 163, and 164 so that the water conduit 101 of the torch main body 100 enters the electrode 161. The retainer cap 166 is put on the front end portion of the torch body 100 at the position of the central axis. Here, a female screw is cut on the inner peripheral surface 166 b at the rear end of the retainer cap 166, and a male screw is cut on the outer peripheral surface 104 b of the holder 104 of the torch body 100. In this state, the plasma attachment 160 is fixed to the torch body 100 by screwing the female screw of the retainer cap 166 with the male screw of the holder 104, and the plasma torch is completed.

  FIG. 3 is a cross-sectional view of the plasma torch.

  By attaching the plasma attachment 160 to the torch body 100, the first, second, and third gas passages 111, 121, and 131 in the torch body 100 are connected to the plasma gas, the secondary gas, and the retainer cap 166, respectively. The tertiary gas passages 113, 123 and 133 communicate with each other.

  That is, the plasma gas passage 112 is formed in front of the first gas outlet 111a. Here, the plasma gas passage 112 communicates with the plasma gas passage 113 through a through hole (not shown) provided in the guide 162, and as a result, the first gas passage 111 communicates with the plasma gas passage 113. The second gas passage 121 communicates with the secondary gas passage 122 at the second gas outlet 121a. A tertiary gas passage 132 is formed in front of the third gas outlet 131a. The tertiary gas passage 132 communicates with the tertiary gas passage 133 through the tertiary gas inlet 133a.

  At the time of plasma cutting, the plasma gas flows from the first gas passage 111 into the plasma gas passage 113 and is turned into plasma by the energy of the arc emitted from the heat-resistant insert 161a to be turned into a plasma arc and ejected from the nozzle orifice 163 to the outside. To do. Further, the secondary gas flows into the secondary gas passages 122 and 123 from the second gas passage 121 and is ejected from the opening 164a of the shield cap 164 to form a secondary gas curtain around the plasma arc. Further, the tertiary gas flows from the third gas passage 131 into the tertiary gas passages 132 and 133 and is ejected toward the outer surface of the shield cap 164 to form a tertiary gas curtain around the secondary gas curtain.

  For plasma cutting, cooling water circulates in the torch body 100 and the plasma attachment 160. That is, the cooling water supplied from the cooling water system 15 to the water conduit 101 flows out from the water conduit outlet 101 a at the tip of the water conduit 101. Then, it passes through the cooling water passage 161 b formed between the outer surface of the water conduit 101 and the inner surface of the electrode 161, and flows into the cooling water passages 171 and 172 provided along the outer periphery of the water conduit 101. Thereafter, the cooling water flows into the cooling water jacket 173 through a cooling water passage (not shown), and is discharged from the rear end of the torch body 100 through a cooling water discharge pipe (not shown).

  Next, a gas cutting attachment (hereinafter referred to as a gas attachment) attached to the tip of the torch body 100 when performing gas cutting will be described.

  4 is a cross-sectional view of the gas attachment, FIG. 4 (a) is a cross-sectional view of a gas attachment main body (hereinafter simply referred to as an attachment main body) 150, and FIG. 4 (b) is a cross-sectional view of an adapter 140 incorporated in the attachment main body 150. It is.

  As shown in FIG. 4A, the attachment main body 150 includes a cylindrical retainer cap 155 for coupling the attachment main body 150 to the torch main body 10 and a length attached to the central axis position of the distal end portion of the retainer cap 155. A cylindrical gas cutting crater 151 is provided. The gas cutting crater 151 includes a long cylindrical metal nozzle main body 152 and a metal nozzle cover 153 that is fitted on the tip side of the nozzle main body 152 at about 2/3. The gas cutting crater 151 is fitted into the opening 155 a at the tip of the retainer cap 155 at a position near the rear end of the portion covered with the nozzle cover 153. A metal nozzle body 152 is exposed at a portion of about 1/3 of the rear end side of the gas cutting crater 151, and this protrudes into the internal space of the retainer cap 155.

  The nozzle main body 152 is provided with a long cylindrical cutting oxygen gas passage 118 penetrating therethrough at the center axis position. The cutting oxygen gas inlet 118 a of the cutting oxygen gas inlet 118 is opened at the rear end of the gas cutting crater 151, and the cutting oxygen gas outlet 118 b is opened at the tip of the gas cutting crater 151.

  A preheated oxygen gas passage 130 is formed in the wall of about の of the rear end side of the nozzle body 152. The preheating gas inlet 130a of the preheating oxygen gas passage 130 is provided on the outer peripheral surface of the rear end side about 1/3 of the nozzle body 152. The preheated oxygen gas passage 130 communicates with a mixed gas passage 129 formed between the nozzle body 152 and the nozzle cover 153. The preheating gas outlet 129b of the mixed gas passage 129 opens around the cutting oxygen gas outlet 118b. Further, the nozzle main body 152 includes a fuel gas passage 128 that is formed obliquely in a direction from the fuel gas inlet 128a provided on the outer peripheral surface of the rear end side approximately 1/3 of the nozzle main body 152 toward the central axis. The fuel gas passage 128 merges with the preheated oxygen gas passage 130.

  A fuel gas passage 125 and a preheated oxygen gas passage 136 are formed in the wall of the retainer cap 155. The fuel gas inlet 125a at the rear end of the fuel gas passage 125 is open to a position where it is connected to the second gas outlet 121 of the torch body 100 when the gas attachment is attached to the torch body 100 (see FIG. 5). The preheated oxygen gas inlet at the rear end of the preheated oxygen gas passage 136 opens to a position communicating with the gas passage 135 in front of the third gas passage 131 of the torch main body 100 when the gas attachment is attached to the main body ( (See FIG. 5).

  The adapter 140 shown in FIG. 4 (b) is a metal member, and has a concave portion in the front half thereof, and the concave portion of the nozzle body 152 shown in FIG. It is fitted to the part and is in close contact with it. The second half of the adapter 140 has the same outer shape as that obtained by combining the electrode 161, the guide 162, and the plasma nozzle 163 of the plasma attachment 160 shown in FIGS. 2 and 3, and the gas attachment is attached to the torch body 100. When attached, it fits closely into the inner sleeve 102 and the nozzle base 106 of the torch body 100 (see FIG. 5).

  A cooling water passage 141 into which the water guide pipe 101 of the torch main body 100 enters is formed at the center axis position of the latter half portion of the adapter 140 (see FIG. 5).

  The adapter 140 has a cutting oxygen gas passage 116, a preheated oxygen gas passage 138, and a fuel gas passage 127 that pass through the wall from the outer peripheral surface upward to the inner peripheral surface of the recess.

  When the adapter 140 is attached to the nozzle body 152, the outlet of the cutting oxygen gas passage 116 communicates with the cutting oxygen gas inlet 118a of the nozzle body 152 via the gas passage 117 (see FIG. 5). Further, the outlet of the preheating oxygen gas passage 138 communicates with the preheating oxygen gas inlet 130a of the nozzle body 152 via the gas passage 139 (see FIG. 5). Further, the outlet of the fuel gas passage 127 communicates with the inlet of the fuel gas passage 128 (see FIG. 5).

  FIG. 5 is a sectional view of the gas torch.

  By attaching the gas attachments 140 and 150 to the torch body 100, the first, second and third gas passages 111, 121 and 131 in the torch body 100 are connected to the cut oxygen gas passage 116 and the fuel in the adapter 140, respectively. The cutting oxygen gas passage 118, the fuel gas passage 128, and the preheating oxygen gas passage 130 of the attachment main body 150 are communicated with each other through the gas passage 127 and the preheating oxygen gas passage 138, respectively.

  That is, a cut oxygen gas passage 115 is formed in front of the first gas outlet 111a, and the first gas passage 111 communicates with the cut oxygen gas passage 116. A cutting oxygen gas passage 117 is formed between the outlet of the cutting oxygen gas passage 116 and the cutting oxygen gas inlet 118a. As a result, the first gas passage 111 and the cut oxygen gas passages 116 and 118 communicate with each other.

  The second gas passage 121 communicates with the fuel gas passage 125 at the second gas outlet 121a. A fuel gas passage 126 is formed in front of the fuel gas outlet 125 b and communicates with the fuel gas passage 127. The fuel gas passage 127 communicates with the fuel gas passage 128 at the outlet thereof. As a result, the second gas passage 121 and the fuel gas passages 125, 127, and 128 communicate with each other.

Further, a preheating oxygen gas passage 135 is formed in front of the third gas outlet 131a. The preheated oxygen gas passage 135 communicates with the preheated oxygen gas passage 136 via the preheated oxygen gas inlet 136a. A preheating oxygen gas passage 137 is formed in front of the preheating oxygen gas outlet 136b.
A preheated oxygen gas passage 139 is formed at the outlet of the preheated oxygen gas passage 138 communicating with the preheated oxygen gas passage 137. The preheated oxygen gas passage 139 is connected to the preheated oxygen gas inlet 130a. As a result, the third gas passage 131 and the preheated oxygen gas passages 136, 138, and 130 communicate with each other.

  At the time of gas cutting, the cutting oxygen gas flows from the first gas passage 111 into the cutting oxygen passage 118 and is ejected from the cutting oxygen gas outlet 118b. Further, when the fuel gas flows from the second gas passage 121 to the fuel gas passage 128 and the preheated oxygen gas flows from the third gas passage 131 to the preheated oxygen gas passage 130, the fuel gas and the preheated oxygen gas flow in the mixed gas passage 129. The mixed gas is ejected from the mixed gas outlet 129b. When this mixed gas is ignited, it is ejected from the mixed gas outlet 129b as a preheating flame.

  Even when the gas torch is used, the cooling water may be circulated in the torch as in the case of the plasma torch. Thereby, since the gas torch is water-cooled, it becomes difficult to cause backfire, which is a problem in the gas torch.

  Next, FIG. 6 shows a circuit diagram of the power supply system 11.

  The power supply system 11 includes a high frequency high voltage circuit 51, a plasma power supply 52, a transistor 53, a changeover switch 54, and a continuity tester 55. One end of the high frequency high voltage circuit 51 is connected to the inner sleeve 102 (see FIG. 2) of the torch main body 100. The other end is connected to the negative terminal of the plasma power source 52 and the changeover switch 54. The changeover switch 54 has an A terminal connected to the workpiece and a B terminal connected to the nozzle base 106 (see FIG. 2). When the gas attachment is attached to the torch body 100 and used as a gas torch, the changeover switch 54 is connected to the A terminal, and when the plasma attachment is attached and used as a plasma torch, the changeover switch is connected to the B terminal. Is done. The plus terminal of the plasma power source 52 is connected to the B terminal of the changeover switch 54 through the transistor 53. In the path between the A terminal of the changeover switch 54 and the workpiece, a continuity tester 55 is incorporated in parallel.

  When used as a plasma torch, the changeover switch 54 is connected to the B terminal. Therefore, the high frequency high voltage circuit 51 applies a high frequency high voltage to the inner sleeve 102 and the nozzle base 106. At this time, the transistor 53 is on. The inner sleeve 102 and the nozzle base 106 are electrically connected to the electrode 161 and the plasma nozzle 163, respectively, and the electrode 161 and the plasma nozzle 163 are insulated by the guide 162 (see FIG. 3). Accordingly, a pilot arc is generated between the electrode and the nozzle, whereby the plasma gas existing in the plasma gas passage 113 is turned into plasma, and the plasma arc is ignited. After the plasma arc is ignited, a plasma arc is sprayed on the workpiece by a voltage applied between the workpiece and the electrode by the plasma power source 52.

  On the other hand, when used as a gas torch, the changeover switch 54 is connected to the A terminal. In this case, the initial height of the gas torch can be set by the following procedure. That is, the torch moving system 17 lowers the gas torch based on an instruction from the controller 18. At this time, when the gas cutting crater 151 comes into contact with the workpiece, the continuity tester 55 detects continuity. Thereby, it can be detected that the gas cutting crater 151 is in contact with the workpiece. Therefore, the controller 18 stops the lowering of the gas torch when this conduction is detected, and thereafter, the controller 18 can automatically control the height of the gas cutting crater 151 with reference to the position at this time.

  Further, a high frequency high voltage is applied between the inner sleeve 102 and the workpiece in a state where the gas cutting crater 151 is slightly raised from the height when the gas cutting crater 151 and the workpiece are in contact with each other. Here, when the gas attachments 140 and 150 are attached to the torch main body 100, the inner sleeve 102 is electrically connected to the nozzle main body 152 through the metal adapter 140 (see FIG. 5). Accordingly, a high frequency high voltage is applied between the nozzle body 152 and the workpiece, and a pilot arc is generated between the nozzle body 152 and the workpiece. Using this pilot arc, the mixed gas ejected from the mixed gas outlet 129b can be automatically ignited.

  Next, the block diagram of the gas system 13 is shown in FIG.

  The gas system 13 includes a first supply passage 71 that supplies gas to the first gas passage 111 of the torch body 100, a second supply passage 72 that supplies gas to the second gas passage 121, and a gas to the third gas passage 131. And a third supply path 73 for supplying. Two gas sources, an oxygen source 64 and a nitrogen source 65, are connected to the first supply path 71, and switching means 61 is provided for selecting any one of them and sending it to the first gas passage 111. . Three gas sources of an air source 66, a propane source 67, and a nitrogen source 68 are connected to the second supply path 72. The mixing means 63 for mixing the propane gas from the propane source 67 and the nitrogen gas from the nitrogen source 68, and the switching means 62 for sending one of the mixed gas of propane and nitrogen and air to the second gas passage 121. With. An oxygen gas source 69 is connected to the second supply path 73 and supplies oxygen gas to the third gas path 131.

  Thereby, for example, when cutting mild steel by plasma cutting, a combination of oxygen gas as plasma gas, air as secondary gas, oxygen gas as tertiary gas can be used, and when cutting stainless steel by plasma cutting, plasma Nitrogen gas can be used for the gas, a mixed gas of propane and nitrogen can be used for the secondary gas, and a combination of nitrogen gas can be used for the tertiary gas. In the case of gas cutting, a combination of cutting oxygen gas, propane as fuel gas, and preheated oxygen gas can be used.

  According to this embodiment, both plasma cutting and gas cutting can be performed with one thermal cutting apparatus. Furthermore, in the thermal cutting device of the present embodiment, plasma cutting and gas cutting can be properly used by replacing the attachment attached to one torch body, so that the cost is lower than that of a conventional thermal cutting device including a gas torch and a plasma torch. And can be downsized.

  Furthermore, in this embodiment, plasma cutting and gas cutting can be performed with a single torch. Therefore, if applied to a small table type plasma cutting machine, it can be combined with gas cutting. Due to capacity restrictions, it is possible to cut a thick mild steel plate, which cannot be cut by plasma cutting, by gas cutting. As a result, the applied plate thickness of one cutting machine is remarkably improved.

  In the case of gas cutting, conventionally, an operator ignites manually or a dedicated ignition circuit is required. However, according to the present embodiment, automatic ignition can be performed using the high voltage circuit used in the plasma torch even if no dedicated ignition circuit is provided.

  Furthermore, in the case of a gas torch, conventionally, the height setting has been performed manually, but according to the present embodiment, this can be performed automatically.

  Moreover, according to this embodiment, even when performing gas cutting, cooling water can be circulated in the torch, and the gas torch can be water-cooled. Thereby, the backfire which becomes a problem with a gas torch becomes difficult to occur.

  The combustible gas can be used not only as a fuel gas for the preheating flame for gas cutting, but also for high-quality cutting of stainless steel by plasma cutting.

  The above-described embodiments of the present invention are examples for explaining the present invention, and are not intended to limit the scope of the present invention only to those embodiments. Those skilled in the art can implement the present invention in various other modes without departing from the gist of the present invention.

  For example, in this embodiment, the gas attachment is separated into the adapter and the gas attachment main body, but these may be configured integrally.

It is a schematic structure figure of a thermal cutting device concerning one embodiment of the present invention. It is sectional drawing of a torch main body and a plasma attachment. It is sectional drawing of a plasma torch. It is sectional drawing of a gas attachment. It is sectional drawing of a gas torch. It is a circuit diagram of a power supply system. It is a block diagram of a gas system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Torch 11 Power supply system 13 Gas system 15 Cooling water system 17 Torch moving system 18 Controller 51 High frequency circuit 52 Plasma power supply 53 Transistor 54 Changeover switch 55 Continuity tester 100 Torch main body 111, 112, 113 First, second, third gas passage 121, 122, 123 Secondary gas passages 131, 132, 133 Tertiary gas passage 140 Adapter 150 Gas attachment body 151 Gas cutting crater 152 Nozzle body 160 Plasma attachment 161 Electrode 163 Plasma nozzle

Claims (6)

A thermal cutting apparatus capable of performing both plasma cutting and gas cutting,
Torch body (100),
Means (13) for supplying at least fuel gas and oxygen gas to the torch body;
A plasma attachment (160) that is detachably attachable to the torch body, and that enables plasma cutting when attached;
A thermal cutting apparatus comprising a gas attachment (140, 150) that is detachably attachable to the torch body and that enables gas cutting when attached.   The thermal cutting device according to claim 1, wherein the plasma attachment and the gas attachment are selectively attached to a tip of the torch body. The plasma attachment has at least an electrode (161), a plasma nozzle (163) surrounding the tip of the electrode, and a retainer cap (166) for fixing the electrode and the plasma nozzle to the torch body. ,
The thermal cutting device according to claim 2, wherein the gas attachment includes a gas cutting crater (151) and a retainer cap (155) for fixing the gas cutting crater to the torch body. The torch body has first, second, and third gas passages (111, 121, 131);
When the plasma attachment is attached to the torch body, at least one of the first, second, and third gas passages of the torch body is a plasma gas passage or a secondary gas passage of the plasma attachment. And communicating with the tertiary gas passage,
When the gas attachment is attached to the torch body, each of the first, second, and third gas passages of the torch body includes a cutting gas passage, a fuel gas passage, and a preheating oxygen passage of the gas attachment. The thermal cutting device according to claim 1, wherein the thermal cutting device communicates with any one of them, the other one, and the remaining one. A high voltage circuit (51) for outputting a high voltage for generating a pilot arc when the plasma attachment is mounted on the torch body;
When the gas attachment is mounted on the torch body, the high voltage circuit applies a high voltage in the vicinity of the gas cutting crater and generates a spark for igniting a preheating flame, and Furthermore, the thermal cutting device of Claim 1 which has. A gas supply source (64-69) for supplying gas to the torch body;
The gas supply source is:
When the plasma attachment is attached to the torch body,
Oxygen or nitrogen is supplied to the first gas passage, air, propane, or a mixed gas of propane and nitrogen is supplied to the second gas passage, and oxygen or nitrogen is supplied to the third gas passage, respectively.
When the gas attachment is attached to the torch body,
The thermal cutting device according to claim 4, wherein oxygen is supplied to the first gas passage, fuel gas is supplied to the second gas passage, and oxygen is supplied to the third gas passage.

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