Manual gas cutting machine

Abstract

A manual gas cutting machine comprises: a body part in which a flow passage through which oxygen flows is formed; and a cutting oxygen valve that can close or open the flow passage. The cutting oxygen valve includes: a cylinder part communicating with the flow passage; a valve that is inserted into the cylinder part, capable of advancing and retreating, and has a valve closing part capable of closing the flow passage; and an operating part that is connected to the valve and rotatable relative to the valve about a rotation axis extending in a direction different from the advance / retreat direction of the valve. By rotating the operating part about the rotation axis, the valve advances and retreats in the advance / retreat direction and can close or open the flow passage.

Description

Manual gas cutter

[0001] This application claims priority to Japanese Patent Application No. 2023-199283, filed on November 24, 2023, the contents of which are incorporated herein by reference.

[0002] Conventionally, there have been gas cutting tools that cut a workpiece such as a steel plate by supplying fuel gas and oxygen. The gas cutting tool heats the cutting portion of the workpiece by emitting a flame from a nozzle at the tip of the gas cutting tool, then emits oxygen into the heated cutting portion to burn it, and then blows away the burned cutting portion with the oxygen to cut the workpiece. Gas cutting tools include manual gas cutting tools that are held by an operator to perform cutting work (for example, Patent Document 1).

[0003] Manual gas cutters are equipped with a cutting oxygen valve that adjusts the amount of oxygen (cutting oxygen) released to cut the workpiece. When an operator uses a manual gas cutter to cut steel or other materials, they may begin cutting from a location other than the edge of the steel plate. In this case, a preheating flame is first used to heat a location on the steel plate. Once the steel plate is red-hot, the cutting oxygen valve is fully opened, a hole is made in the steel plate (piercing), and then the cutting begins.

[0004] Conventionally, cutting oxygen valves installed on manual gas cutters are either handle (knob) type or lever type. Handle type cutting oxygen valves allow the flow rate of cutting oxygen to be adjusted by rotating the handle (knob). When the handle is released, the flow rate of cutting oxygen is maintained. Lever type cutting oxygen valves allow the flow rate of cutting oxygen to be fully opened by squeezing the lever, and the flow of cutting oxygen to be shut off by releasing the lever.

[0005] Japanese Registered Utility Model No. 2544700

[0006] However, when using a handle-type cutting oxygen valve, the operator must hold the body of the manual gas cutter with one hand and rotate the handle of the cutting oxygen valve with the other, which can cause the cutting oxygen stream emitted from the nozzle to miss the piercing point. This makes it difficult to fix the position of the manual gas cutter, which can lead to poor workability. Furthermore, when using a lever-type cutting oxygen valve, the operator must continue to hold the lever while cutting, which can tire the operator's hands and make long-term work difficult, resulting in poor workability.

[0007] In view of the above circumstances, an object of the present disclosure is to provide a manual gas cutter with improved operability.

[0008] A manual gas cutter according to a first aspect of the present disclosure comprises a main body portion having a flow path formed therein through which oxygen flows, and a cutting oxygen valve capable of closing or opening the flow path, wherein the cutting oxygen valve comprises a cylinder portion connected to the flow path, a valve that is inserted into the cylinder portion and can move back and forth and has a valve closing portion that can close the flow path, and an operating unit connected to the valve and rotatable relative to the valve around a rotation axis that extends in a direction different from the direction in which the valve moves back and forth, and wherein the valve can move back and forth in the direction in which it moves back and forth by rotating the operating unit around the rotation axis, thereby closing or opening the flow path.

[0009] According to the manual gas cutter of the present disclosure, it is possible to provide a manual gas cutter with improved operability.

[0010] Fig. 1 is a diagram showing an example of the configuration of a manual gas cutter according to the present embodiment; Fig. 2 is a diagram showing an example of the outer shape of the manual gas cutter; Fig. 3 is a cross-sectional view showing the cutting oxygen valve of the manual gas cutter when an operating part of the cutting oxygen valve is located at a first position; Fig. 4 is a cross-sectional view showing the cutting oxygen valve when the operating part is located at a second position; Fig. 5 is a cross-sectional view showing the cutting oxygen valve when the operating part is located at a third position.

[0011] An embodiment of the present disclosure will be described below with reference to the drawings. Fig. 1 is a diagram showing an example of the configuration of a manual gas cutter 1 according to this embodiment. Fig. 2 is a diagram showing an example of the outer shape of the manual gas cutter 1.

[0012] The manual gas cutter 1 comprises a main body 10, an oxygen supply port 20, a fuel gas supply port 30, a torch 40, a cutting oxygen valve 50, a preheating oxygen valve 60, and a fuel gas valve 70.

[0013] The manual gas cutting tool 1 is a gas cutting tool in which oxygen supplied from an oxygen supply port 20 and fuel gas supplied from a fuel gas supply port 30 are released from a torch 40 via a flow path (conduit) provided inside the main body 10.

[0014] An operator can ignite the gas released from the manual gas cutting tool 1 with a lighter or the like, thereby causing a flame P to be emitted from the torch 40. The operator applies the flame P emitted from the manual gas cutting tool 1 to the cutting portion of the workpiece W to heat the cutting portion, releases oxygen into the heated cutting portion to burn it, and blows away the burned cutting portion with the oxygen, thereby cutting the workpiece W.

[0015] 1 and 2 , in the manual gas cutter 1, the horizontal direction in which mainly oxygen and fuel gas flow is defined as the "flow direction A," the side on which the oxygen supply port 20 and the fuel gas supply port 30 are provided is defined as the "upstream side A1" in the flow direction A, and the side opposite the upstream side A1 is defined as the "downstream side A2" in the flow direction A. Furthermore, the vertical direction in the manual gas cutter 1 is defined as the "up-down direction B," the vertically upward direction is defined as the "upper side B1" in the vertical direction B, and the vertically downward direction is defined as the "lower side B2" in the vertical direction B. Furthermore, the direction perpendicular to the flow direction A and the vertical direction B is defined as the "width direction C."

[0016] In this embodiment, an example will be described in which the flame P is emitted from the manual gas cutter 1 in a vertical direction toward the workpiece W, but the orientation in which the manual gas cutter 1 is used is not limited to this, and for example, the manual gas cutter 1 may be used so as to emit the flame P in a horizontal direction. In this case, the oxygen and fuel gas may flow mainly vertically in the manual gas cutter 1.

[0017] The main body 10 includes a grip 11 , a cutting oxygen tube 12 , and a mixing tube 13 .

[0018] 1, in the manual gas cutter 1, oxygen supplied from the oxygen supply port 20 branches into oxygen (cutting oxygen) that passes through the cutting oxygen valve 50 and oxygen (preheated oxygen) that passes through the preheating oxygen valve 60. The fuel gas supplied from the fuel gas supply port 30 passes through the fuel gas valve 70, and then merges with and is mixed with the preheated oxygen to form a mixed gas.

[0019] The grip 11 is a gripping portion of the main body 10 that is primarily gripped by an operator's hand. Inside the grip 11, a flow path through which oxygen supplied from the oxygen supply port 20 flows and a flow path through which fuel gas supplied from the fuel gas supply port 30 flows are formed.

[0020] The cutting oxygen pipe 12 is a conduit through which cutting oxygen flows via a cutting oxygen valve 50. The mixing pipe 13 is a conduit through which a mixed gas of preheated oxygen and fuel gas flows.

[0021] The oxygen supply port 20 is provided on the upstream side A1 of the main body 10 and is an opening through which oxygen can be supplied from the outside into the inside of the manual gas cutter 1. For example, the oxygen supply port 20 is connected to an oxygen cylinder (not shown) filled with oxygen by a hose (not shown) via a pressure regulator. Oxygen is supplied from the oxygen cylinder to the oxygen supply port 20 via the pressure regulator and the hose, and oxygen flows into the inside of the manual gas cutter 1 from the oxygen supply port 20.

[0022] Oxygen flowing into the manual gas cutter 1 from the oxygen supply port 20 flows through a flow path formed in the main body 10 to the cutting oxygen valve 50 and the preheating oxygen valve 60 .

[0023] The fuel gas supply port 30 is provided on the upstream side A1 of the main body 10 and is an opening through which fuel gas can be supplied from the outside into the interior of the manual gas cutter 1. For example, the fuel gas supply port 30 is connected to a fuel gas cylinder (not shown) filled with fuel gas by a hose (not shown) via a pressure regulator. Fuel gas is supplied from the fuel gas cylinder to the fuel gas supply port 30 via the pressure regulator and the hose, and the fuel gas flows from the fuel gas supply port 30 into the interior of the manual gas cutter 1.

[0024] The fuel gas that flows into the manual gas cutter 1 from the fuel gas supply port 30 flows to the fuel gas valve 70 via a flow path formed in the main body 10 .

[0025] The torch 40 is provided on the downstream side A2 of the main body 10, and is a portion into which the cutting oxygen that has passed through the cutting oxygen pipe 12 and the mixed gas that has passed through the mixing pipe 13 flow. A nozzle 41 that can release oxygen and the mixed gas from a tip 41 a is provided at the tip of the torch 40. As shown in Fig. 1, the nozzle 41 is provided with an oxygen release flow path 42 through which the oxygen that has flowed in from the main body 10 flows, and a gas release flow path 43 through which the mixed gas that has flowed in from the main body 10 flows.

[0026] The cutting oxygen valve 50 is provided in the main body 10 and is a valve that can change the flow rate of oxygen flowing from the oxygen supply port 20 to the oxygen release flow path 42. By operating the cutting oxygen valve 50, the operator can change the amount of oxygen (cutting oxygen) released from the tip 41 a of the nozzle 41. Details of the cutting oxygen valve 50 will be described later.

[0027] The preheating oxygen valve 60 is provided in the main body 10 and is a valve that can change the flow rate of oxygen (preheated oxygen) that flows from the oxygen supply port 20 to the gas release flow path 43. By operating the preheating oxygen valve 60, the operator can change the amount of preheated oxygen that is mixed with fuel gas and released from the tip 41 a of the burner nozzle 41. By operating the preheating oxygen valve 60, the operator can change the mixture ratio of preheated oxygen and fuel gas.

[0028] The fuel gas valve 70 is provided in the main body 10 and is capable of changing the flow rate of fuel gas flowing from the fuel gas supply port 30 to the gas release flow path 43. By operating the fuel gas valve 70, the operator can change the amount of fuel gas mixed with preheated oxygen and released from the tip 41a of the nozzle 41 as a mixed gas. By operating the fuel gas valve 70, the operator can change the mixture ratio of preheated oxygen and fuel gas. The preheating oxygen valve 60 and the fuel gas valve 70 can employ known valve structures used in conventional manual gas cutters.

[0029] The operator can hold the grip 11 with one hand and operate the cutting oxygen valve 50, preheating oxygen valve 60, and fuel gas valve 70 with the other hand to change the amount of cutting oxygen and mixed gas released from the tip 41 a of the nozzle 41. The operator may also operate the cutting oxygen valve 50, preheating oxygen valve 60, and fuel gas valve 70 with the hand holding the grip 11.

[0030] Next, a description will be given of the configuration of the cutting oxygen valve 50. Fig. 3 is a cross-sectional view showing the cutting oxygen valve 50. The cutting oxygen valve 50 shown in Fig. 3 is the cutting oxygen valve 50 in which an operating unit 57 (described later) is located at a first position P1.

[0031] The cutting oxygen valve 50 includes a cylinder portion 51 , a valve 54 , a biasing member 55 , an O-ring 56 , an operating portion 57 , and a pivot pin 58 .

[0032] The cylinder 51 includes a nut 52 and a packing 53. The cylinder 51 is provided in the main body 10. In the main body 10, a first flow path 11a, a second flow path 11b, and a third flow path 11c, which are flow paths through which oxygen flows, are formed near the cutting oxygen valve 50.

[0033] A cylinder flow path 51a communicating with the first flow path 11a is formed in the cylinder portion 51. The first flow path 11a and the cylinder flow path 51a communicate with each other through a communication hole 51b provided below the cylinder flow path 51a at a position B2 below the cylinder flow path 51a.

[0034] Oxygen flowing into the main body 10 from the oxygen supply port 20 flows through the first flow path 11a to the vicinity of the cutting oxygen valve 50. Near the cutting oxygen valve 50, the oxygen flowing through the first flow path 11a branches into a cylinder flow path 51a and a second flow path 11b.

[0035] 3, the second flow passage 11b is connected to the downstream side A2 of the first flow passage 11a and extends downward B2. Oxygen flowing from the first flow passage 11a into the second flow passage 11b flows through the second flow passage 11b to the preheating oxygen valve 60. When the preheating oxygen valve 60 is open, the oxygen flowing through the second flow passage 11b merges with the fuel gas that has passed through the fuel gas valve 70 to form a mixed gas. As described above, the mixed gas flows into the gas discharge passage 43 of the burner nozzle 41 and is discharged from the tip 41a of the burner nozzle 41.

[0036] The cylinder flow path 51a is connected to the third flow path 11c on the downstream side A2. Therefore, oxygen flowing from the first flow path 11a into the cylinder flow path 51a flows from the cylinder flow path 51a into the third flow path 11c. The oxygen (cutting oxygen) flowing into the third flow path 11c passes through the inside of the cutting oxygen pipe 12, flows into the oxygen release flow path 42 of the nozzle 41, and is released from the tip 41a of the nozzle 41. The cylinder flow path 51a is open upward B1.

[0037] The nut portion 52 is provided above the cylinder flow passage 51a in a position B1 above the cylinder flow passage 51a. The nut portion 52 is, for example, a gland nut, and is connected by being threaded into a groove provided in the main body portion 10.

[0038] The packing 53 is provided below the nut portion 52 at a position B2. The packing 53 is a packing member that fills a gap in the vertical direction B between the nut portion 52 and a portion of the main body 10 that is screwed onto the nut portion 52.

[0039] The valve 54 is a cylindrical member centered on an axis O1 extending in the vertical direction B, and is inserted into the cylinder flow path 51a of the cylinder portion 51 in the vertical direction B. Here, the cylindrical shape does not necessarily mean that the valve 54 is a cylinder. The valve 54 includes a valve core rod 54a, a valve large-diameter portion 54b, and a valve closing portion 54c.

[0040] As shown in FIG. 3, the valve stem 54a is inserted in the vertical direction B through openings provided in the nut portion 52 and the packing 53.

[0041] The large-diameter valve portion 54b is provided below the valve stem 54a at B2 and has a diameter larger than that of the valve stem 54a. The diameter of the large-diameter valve portion 54b is slightly smaller than the diameter of the cylinder flow path 51a.

[0042] The valve closing portion 54c is provided below the valve large diameter portion 54b at B2 and forms the tip of the valve 54 at the lower B2. As shown in Fig. 3, the valve closing portion 54c has a conical shape that tapers downward at B2. Here, the conical shape does not necessarily have to be a cone.

[0043] 3 is capable of closing the communication hole 51 b by contacting the edge of the communication hole 51 b provided at the lower portion B2 of the cylinder flow path 51 a. When the communication hole 51 b is closed by the valve closing part 54 c, oxygen flowing through the first flow path 11 a does not flow from the first flow path 11 a into the cylinder flow path 51 a.

[0044] 3, the biasing member 55 is a spring member through which the valve stem 54a is inserted, and is disposed between the packing 53 and the valve large-diameter portion 54b in the vertical direction B. The communication hole 51b of the cylinder flow path 51a is closed by the valve closing portion 54c of the valve 54, which is biased downward B2 by the biasing member 55.

[0045] The O-ring 56 is an annular O-ring made of rubber or the like, and is provided in a recess formed in the outer peripheral surface of the valve large-diameter portion 54b, as shown in Fig. 3. The O-ring 56 is sandwiched between the valve large-diameter portion 54b and the cylinder flow path 51a in the horizontal direction (flow direction A and width direction C), and is in contact with the valve large-diameter portion 54b and the cylinder flow path 51a.

[0046] Since the O-ring 56 fills the gap between the large diameter valve portion 54b and the cylinder flow path 51a, oxygen that flows from the first flow path 11a into the cylinder flow path 51a does not leak from the opening at the upper B1 of the cylinder flow path 51a.

[0047] The operating part 57 is provided above B1 of the nut part 52. The pivot pin 58 is a rod-shaped member extending in the width direction C, and is an axial member that rotatably connects the operating part 57 and the valve core rod 54a. The operating part 57 is provided rotatably with respect to the valve 54 via the pivot pin 58, with a rotation axis O2 extending in the width direction C as the rotation center.

[0048] The operating part 57 includes an operating part body 571 and a trigger 572. The operating part body 571 is a main body portion of the operating part 57 that is connected to the valve stem 54a by a shaft pin 58.

[0049] The trigger 572 is a protruding part that protrudes from the operating part body 571 in a direction away from the rotation axis O2. The trigger 572 is a grip part that can be gripped by hand when an operator operates the cutting oxygen valve 50.

[0050] 3, the direction in which the operating unit 57 rotates clockwise around the rotation axis O2 is referred to as a first rotation direction R1, and the direction in which the operating unit 57 rotates counterclockwise opposite to the first rotation direction R1 is referred to as a second rotation direction R2. Also, as shown in FIG. 3, the position of the operating unit 57 when the valve closing unit 54c closes the communication hole 51b of the cylinder flow path 51a and thereby closes the flow path through which oxygen flows is referred to as a first position P1.

[0051] Fig. 4 is a cross-sectional view showing the cutting oxygen valve 50. The cutting oxygen valve 50 shown in Fig. 4 is the cutting oxygen valve 50 in which the operating part 57 located at the first position P1 has been rotated in the first rotation direction R1.

[0052] When the operating unit 57 is positioned at the first position P1 shown in FIG. 3 , the first side 571a of the operating unit body 571 faces the upper B1 surface (cylinder upper end) 52s of the nut portion 52 of the cylinder portion 51, separated by a small gap. Here, the cylinder upper end 52s refers to the upper B1 end (top end) of the cylinder portion 51, and in the example shown in FIG. 3 , it refers to the upper B1 surface of the nut portion 52. When the operating unit 57 is positioned at the first position P1, the first side 571a of the operating unit body 571 forms a surface facing the cylinder portion 51. In the example shown in FIG. 3 , the trigger 572 extends upward B1 from the operating unit body 571, and the first side 571a forms the lower B2 surface of the operating unit body 571. In this case, the distance from the rotation axis O2 of the operating unit 57 to the cylinder upper end 52s is referred to as a first distance (distance) L1.

[0053] 4, the second side portion 571b of the operating portion body 571 is in contact with the cylinder upper end portion 52s. When the operating portion 57 is located at the first position P1 shown in FIG. 3, the second side portion 571b forms a surface facing the upstream side A1.

[0054] As the operating unit 57 rotates in the first rotation direction R1, the second side portion 571b moves downward B2 from the operating unit 57 and comes into contact with the cylinder upper end 52s while facing each other in the up-down direction B. At this time, the distance from the rotation axis O2 of the operating unit 57 to the cylinder upper end 52s is referred to as a second distance (distance) L2. The second distance L2 is greater than the first distance L1.

[0055] Because the first distance L1 is smaller than the second distance L2, when the operating unit 57 rotates from the first position P1 to the second position P2, the rotation axis O2 of the operating unit 57 moves upward B1. That is, the pivot pin 58 moves upward B1.

[0056] Here, the valve 54 is provided so as to be able to move back and forth in the vertical direction B. Therefore, when the pivot pin 58 connecting the operating part 57 and the valve 54 moves upward B1, the valve 54 also moves upward B1.

[0057] When the valve 54 moves upward B1, the valve closing portion 54c moves upward B1 away from the communication hole 51b of the cylinder flow path 51a, opening the communication hole 51b, as shown in Fig. 4. At this time, the oxygen flow path formed by the first flow path 11a and the cylinder flow path 51a is opened, allowing oxygen to flow from the first flow path 11a into the cylinder flow path 51a.

[0058] The position of the operating part 57 when the valve closing part 54c does not block the communication hole 51b of the cylinder flow path 51a and the flow path through which oxygen flows is referred to as the second position P2. The operating part 57 of the cutting oxygen valve 50 shown in FIG. 4 is located in the second position P2.

[0059] When the operating part 57 is in the first position P1 and the valve 54 is closing the oxygen flow path, the operator rotates the operating part 57 in the first rotation direction R1 about the rotation axis O2 to the second position P2. By moving the operating part 57 to the second position P2, the valve 54 moves upward B1, and the oxygen flow path that was closed by the valve 54 is opened. When the flow path is opened, oxygen that has flowed into the manual gas cutter 1 from the oxygen supply port 20 flows through the first flow path 11a, the cylinder flow path 51a, and the third flow path 11c in this order, and is released from the tip 41a of the nozzle 41.

[0060] In the example shown in Fig. 3, the first distance L1 is the distance in the vertical direction B from the rotation axis O2 to the cylinder upper end 52s when the operating unit 57 is located at the first position P1. In the example shown in Fig. 4, the second distance L2 is the distance in the vertical direction B from the rotation axis O2 to the cylinder upper end 52s when the operating unit 57 is located at the second position P2. The first distance L1 and the second distance L2 only need to indicate the distance from the rotation axis O2 to the cylinder upper end 52s, and are not limited to the distance in the vertical direction B.

[0061] In addition, in the operation unit main body 571 of the operation unit 57, the first side portion 571a and the second side portion 571b are connected by a third side portion 571c. The third side portion 571c is an arc-shaped surface (R-surface) in the cross-sectional views shown in Figures 3 and 4. Here, the arc-shaped surface does not have to be strictly an arc-shaped surface.

[0062] When the valve 54, which is movable in the vertical direction B, moves upward B1, it is urged downward B2 by the urging member 55. When the operating part 57 rotates from the first position P1 to the second position P2, it is urged downward B2 by the urging member 55 via the pivot pin 58 and the valve 54.

[0063] Therefore, when the operating unit 57 rotates from the first position P1 to the second position P2, the operating unit 57 rotates from the upstream side A1 end of the first side portion 571a to the second side portion 571b while contacting the cylinder upper end 52s. Specifically, as the operating unit main body 571 rotates from the first position P1 to the second position P2, it rotates in the first rotation direction R1 while contacting the cylinder upper end 52s in the following order: the upstream side A1 end of the first side portion 571a, the third side portion 571c, and the second side portion 571b. Because the third side portion 571c has an arc shape in a cross section parallel to the up-down direction B, the operating unit 57 can rotate smoothly in the first rotation direction R1. Therefore, the operator can rotate the operating unit 57 from the first position P1 to the second position P2 without requiring much force. Furthermore, the operator can easily rotate the operating unit 57 by gripping the trigger 572.

[0064] The operating unit 57 is held in the first position P1 or the second position P2 because it is pulled downward B2 by the valve closing unit 54c, which is biased by the biasing member 55. Therefore, when an operator rotates the operating unit 57 from the first position P1 to the second position P2 by hand and then releases the operating unit 57, the operating unit 57 is held in the second position P2.

[0065] Fig. 5 is a cross-sectional view showing the cutting oxygen valve 50. The cutting oxygen valve 50 shown in Fig. 5 is the cutting oxygen valve 50 in which the operating part 57 located at the first position P1 has been rotated in the second rotation direction R2.

[0066] With the operating unit 57 positioned at the first position P1 shown in FIG. 3 , the operator rotates the operating unit 57 in the second rotation direction R2 by pressing the trigger 572 toward the downstream side A2. At this time, the operating unit 57 rotates in the second rotation direction R2 relative to the valve 54 around the rotation axis O2 as the rotation center, and further rotates around the end of the first side portion 571a on the downstream side A2 as the rotation center. When the trigger 572 is pressed toward the downstream side A2, the trigger 572 tilts toward the downstream side A2 with the end of the first side portion 571a on the downstream side A2 in contact with the cylinder upper end portion 52s.

[0067] 5, the pivot pin 58 and the valve 54 move upward B1, and the valve closing portion 54c moves away from the communication hole 51b of the cylinder flow path 51a, opening the communication hole 51b and allowing oxygen to flow from the first flow path 11a into the cylinder flow path 51a. In other words, the oxygen flow path is opened.

[0068] The position of the operating part 57 when it is rotated in the second rotation direction R2 from the first position P1 and the end of the upstream side A1 of the first side portion 571a is separated from the cylinder upper end 52s and floats is referred to as the third position P3. The operating part 57 of the cutting oxygen valve 50 shown in FIG. 5 is located in the third position P3. When the operating part 57 is located in the third position P3, the oxygen flow path is open. When the operating part 57 is located in the third position P3, the distance (third distance) L3 from the rotation axis O2 to the cylinder upper end 52s is greater than the first distance L1.

[0069] When the operating part 57 is positioned at the third position P3, the upstream end A1 of the first side part 571a is floating above the upper end 52s of the cylinder compared to when the operating part 57 is positioned at the first position P1. Therefore, when the operator releases the operating part 57, the valve 54, which is biased by the biasing member 55, is pulled downward B2 and returns to the first position P1.

[0070] When the operating unit 57 is positioned at the first position P1 or the second position P2, it remains in that position (first position P1 or second position P2) even if the operator releases the operating unit 57. Furthermore, because the first side portion 571a and the second side portion 571b are connected by the third side portion 571c, the operator can rotate the operating unit 57 in the first rotation direction R1 from the first position P1 to the second position P2 without requiring much force. Furthermore, the operator can rotate the operating unit 57 from the first position P1 in the second rotation direction R2 to the third position P3, and then release the operating unit 57 from the third position P3 to return the operating unit 57 to the first position P1 using the biasing member 55. The dimensions of each component of the cutting oxygen valve 50 are set to allow these operations to be performed satisfactorily.

[0071] Thus, the cutting oxygen valve 50 of the manual gas cutter 1 includes the valve 54 having the valve closing portion 54c that can close the flow path through which oxygen flows, and the operating portion 57 that is connected to the valve 54 and can rotate relative to the valve 54 around the rotation axis O2. The valve 54 can move back and forth in the vertical direction (advance / retract direction) B by rotating the operating portion 57 around the rotation axis O2, and can close or open the flow path through which oxygen flows in the main body 10.

[0072] Next, we will explain an example of how to use the manual gas cutter 1. First, the operator holds the grip 11 with one hand (for example, the right hand) and operates the preheating oxygen valve 60 and the fuel gas valve 70 with the other hand (for example, the left hand), causing a mixed gas of oxygen (preheated oxygen) and fuel gas to be released from the tip 41 a of the nozzle 41.

[0073] The worker ignites the mixed gas emitted from the tip 41 a of the nozzle 41 with a lighter or the like, causing a flame P to be emitted from the tip 41 a of the nozzle 41. The worker applies the flame P emitted from the nozzle 41 to the portion to be cut of the object W to heat the portion to be cut of the object W.

[0074] At this time, the operating part 57 of the cutting oxygen valve 50 is located at the first position P1, and the flow path through which the cutting oxygen flows is closed by the valve 54. Specifically, the valve closing part 54c closes the communication hole 51b that connects the first flow path 11a and the cylinder flow path 51a. Therefore, no cutting oxygen is released from the tip 41a of the nozzle 41. Furthermore, even if the operator is not operating the cutting oxygen valve 50, the operating part 57 is held at the first position P1.

[0075] Next, the operator operates the cutting oxygen valve 50 to open the flow path of the cutting oxygen and release the cutting oxygen from the tip 41a of the nozzle 41. Specifically, the operator holds the trigger 572 of the operating part 57 with the other hand and rotates the operating part 57 from the first position P1 to the second position P2 to move the valve 54 upward B1 and open the communication hole 51b of the cylinder flow path 51a.

[0076] When the communication hole 51b of the cylinder flow path 51a is opened, oxygen (cutting oxygen) flows through the first flow path 11a, the cylinder flow path 51a, and the third flow path 11c in that order, enters the oxygen release flow path 42 of the nozzle 41, and is released from the tip 41a of the nozzle 41.

[0077] The worker burns the cutting portion of the heated workpiece W by releasing cutting oxygen onto the cutting portion, and then cuts the workpiece W by blowing away the burned cutting portion with the cutting oxygen.

[0078] The operator can quickly open the flow path of the cutting oxygen by rotating the operating part 57 from the first position P1 to the second position P2, and easily cut the workpiece W. After rotating the operating part 57 from the first position P1 to the second position P2, the operating part 57 is held in the second position P2 even if the operator does not operate the cutting oxygen valve 50.

[0079] The manual gas cutter 1 can easily release cutting oxygen by rotating the operating part 57 of the cutting oxygen valve 50 from the first position P1 to the second position P2, and therefore, compared to manual gas cutters equipped with conventional handle-type cutting oxygen valves, the cutting oxygen stream can be prevented from straying from the cutting portion of the workpiece W, improving workability. By providing the manual gas cutter 1 with the cutting oxygen valve 50, even operators with little skill can easily perform cutting operations such as piercing.

[0080] Furthermore, since the operating part 57, which is located in the second position P2, is maintained in the second position P2 even if the operator releases it, there is no need to continue to press it down with the hand as with conventional lever-type cut-off oxygen valves. This reduces hand fatigue for the operator and improves workability.

[0081] 3, the trigger 572 of the operating unit 57 located at the first position P1 extends upward B1 from the operating unit 57. As shown in Fig. 4, the trigger 572 of the operating unit 57 located at the second position P2 extends upstream A1 from the operating unit 57. Therefore, the operator can easily visually determine whether the operating unit 57 is located at the first position P1 or the second position P2, and can easily determine whether the flow path of the cutting oxygen is closed or open.

[0082] To stop the release of cutting oxygen, the operator grips the trigger 572 of the operating part 57 located at the second position P2 and rotates the operating part 57 to the first position P1 to close the flow path of cutting oxygen with the valve 54. When the flow path of cutting oxygen is closed by the valve 54, the release of cutting oxygen at the tip 41 a of the nozzle 41 is stopped.

[0083] When cutting off-cut material or scrap with a short cutting time, the worker may frequently open and close the cutting oxygen valve 50. In this case, the worker rotates the operating part 57, which is located in the first position P1, to the third position P3 to perform a short cutting operation.

[0084] Specifically, the operator presses the trigger 572 of the operating unit 57 located at the first position P1 toward the downstream side A2. At this time, the operator may press the trigger 572 with the hand that is not holding the grip portion 11, or may press the trigger 572 with the thumb or the like of the hand that is holding the grip portion 11.

[0085] By pressing the trigger 572 toward the downstream side A2, the valve 54 is pulled upward B1, and the communication hole 51b of the cylinder flow path 51a is opened. When the flow path for cutting oxygen is opened, cutting oxygen flows from the first flow path 11a into the cylinder flow path 51a and is released from the tip 41a of the nozzle 41, allowing the operator to perform cutting work.

[0086] At this time, the operator can release the operating part 57 located in the third position P3, causing the biasing member 55 to return the operating part 57 to the first position P1, and close the flow path of the cutting oxygen again with the valve 54. Furthermore, by again pushing the trigger 572 of the operating part 57 that has returned to the first position P1 toward the downstream side A2, the flow path of the cutting oxygen can be opened again, and cutting work can be performed.

[0087] In this way, the operator can easily repeatedly open and close the cutting oxygen valve 50 by repeatedly pressing the trigger 572 and releasing the trigger 572. Therefore, even when cutting off-cut material or scrap with a short cutting time, the operator can easily open and close the cutting oxygen valve 50 frequently.

[0088] When returning the operating unit 57 from the third position P3 to the first position P1, the operator may reduce the force pressing the trigger 572 without releasing the trigger 572, so that the biasing member 55 returns the operating unit 57 to the first position P1.

[0089] The manual gas cutter 1 of this embodiment includes a main body 10 having a flow path (first flow path) 11a through which oxygen flows, and a cutting oxygen valve 50 that can close or open the flow path 11a. The cutting oxygen valve 50 includes a cylinder 51 that communicates with the flow path 11a, a valve 54 that is inserted into the cylinder 51 and is movable forward and backward, and has a valve closing portion 54c that can close the flow path 11a, and an operating part 57 that is connected to the valve 54 and is rotatable relative to the valve 54 about a rotation axis O2 that extends in a direction different from the forward and backward direction of the valve 54. The valve 54 can be moved forward and backward by rotating the operating part 57 about the rotation axis O2. This allows the valve 54 to close or open the flow path 11a.

[0090] Therefore, compared to a manual gas cutter equipped with a conventional handle (knob) type cutting oxygen valve, the manual gas cutter 1 is less likely to direct the cutting oxygen stream away from the cutting site when releasing cutting oxygen onto the workpiece W. Also, compared to a manual gas cutter equipped with a conventional lever type cutting oxygen valve, the manual gas cutter 1 can reduce hand fatigue when releasing cutting oxygen. As a result, a manual gas cutter 1 with improved operability can be provided.

[0091] While one embodiment of the present disclosure has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the present disclosure. Furthermore, the components shown in the above-described embodiment and the following modified examples can be appropriately combined to form a configuration.

[0092] (Variation 1) In the above embodiment, the cutting oxygen valve 50 closes the flow path through which oxygen flows when the trigger 572 of the operating unit 57 is extended upward (position) B1 and opens the flow path through which oxygen flows when the trigger 572 is extended toward the upstream side A1, but the configuration of the cutting oxygen valve is not limited to this. The cutting oxygen valve may be configured to open the flow path through which oxygen flows when the trigger of the operating unit is extended upward (position) B1 and close the flow path through which oxygen flows when the trigger is extended toward the upstream side A1.

[0093] In the operating unit 57 of the above embodiment, the distance (first distance) L1 from the rotation axis O2 to the upper end 52s of the cylinder when the trigger 572 extends upward B1 is smaller than the distance (second distance) L2 from the rotation axis O2 to the upper end 52s of the cylinder when the trigger 572 extends upstream A1.

[0094] Conversely, the distance from the rotation axis O2 to the upper end of the cylinder when the trigger extends upstream A1 may be made smaller than the distance from the rotation axis O2 to the upper end of the cylinder when the trigger extends upward B1.

[0095] In this way, the cutoff oxygen valve can be configured so that the oxygen flow path is blocked when the trigger is extended to the upstream side A1, and the oxygen flow path is opened when the trigger is extended to the upper side B1.

[0096] In this case, when cutting off scrap material or cutting scrap with a short cutting time, the valve closes the oxygen flow path, and with the trigger of the operating unit extended toward the upstream side A1, the valve can be pulled upward toward the upstream side B1 by pressing the trigger downward toward the downstream side B2. Specifically, by pressing the trigger downward toward the downstream side B2, the operating unit rotates in the first rotation direction R1 around the upstream side A1 end of the second side portion as the rotation center, and the valve is pulled upward toward the upstream side B1. As with the cutting oxygen valve 50 of the above embodiment, in which the oxygen flow path can be opened by pressing the trigger 572 toward the downstream side A2, the cutting oxygen valve can be easily and frequently opened and closed by repeatedly pressing the trigger downward toward the downstream side B2 and releasing the trigger.

[0097] (Variation 2) In the above embodiment, the operating part 57 of the cutting oxygen valve 50 is rotatable around a rotation axis O2 extending in the width direction C. However, the configuration of the cutting oxygen valve is not limited to this. The operating part of the cutting oxygen valve may be rotatable around a rotation axis extending in the forward / backward direction of the valve.

[0098] For example, the operating unit may be rotatable around an axis O1 extending in the vertical direction B. In this case, the valve connected to the operating unit via a pivot pin may also be rotatable around the axis O1 together with the operating unit.

[0099] When the operation unit is rotatable around the axis O1, the operator can change the angle of the operation unit relative to the main body unit to any angle, thereby adjusting it to an angle that is easy for the operator to operate. The operator adjusts the operation unit to an angle that is easy for the operator by making it rotatable around the axis O1, and then rotates it around a rotation axis (e.g., rotation axis O2) that extends in a direction different from the axis O1 to rotate it between a first position and a second position.

[0100] (Modification 3) In the above embodiment, the valve 54 of the cutting oxygen valve 50 can close the oxygen flow path by the valve closing portion 54c provided at the tip, but the form of the cutting oxygen valve is not limited to this.

[0101] The valve of the cut oxygen valve may have a valve closing portion in the middle in the vertical direction B, for example. For example, with respect to an oxygen flow path extending in the flow direction A, the valve moves up and down in the vertical direction B to block the oxygen flow path. In a valve that moves up and down in the vertical direction B, when the flow path and the valve closing portion overlap in a plan view in the flow direction A, the flow path is closed by the valve closing portion, and the flow of oxygen is stopped. Also, when the flow path and the valve closing portion do not overlap in a plan view in the flow direction A, the flow path is open. When the flow path is open, for example, an opening provided in the valve may overlap with the flow path in a plan view in the flow direction A. In this case, oxygen flows through the flow path and the opening in the valve.

[0102] 1 Manual gas cutter 10 Main body 11 Grip 11a First flow path (flow path, flow path through which oxygen flows) 20 Oxygen supply port 30 Fuel gas supply port 40 Torch 41 Nozzle 50 Cutting oxygen valve 51 Cylinder 51a Cylinder flow path 51b Communication hole 52 Nut 52s Cylinder upper end 54 Valve 54a Valve stem 54b Large diameter valve portion 54c Valve closing portion 55 Biasing member 57 Operating portion 571 Operating portion main body 571a First side portion 571b Second side portion 572 Trigger 58 Axle pin 60 Preheating oxygen valve 70 Fuel gas valve P1 First position P2 Second position P3 Third position R1 First rotation direction R2 Second rotation direction O1 Axis O2 Rotation axis L1 First distance (distance) L2 Second distance (distance) L3 Third distance (distance) P Flame W Object to be cut A Flow direction A1 Upstream side A2 Downstream side B Vertical direction (advance / retreat direction) B1 Upward B2 Downward C Width direction

Claims

1. A manual gas cutter comprising: a main body portion having a flow path through which oxygen flows; and a cutting oxygen valve capable of closing or opening the flow path, wherein the cutting oxygen valve comprises: a cylinder portion communicating with the flow path; a valve that is inserted into the cylinder portion and can move forward and backward, and has a valve closing portion capable of closing the flow path; and an operating portion connected to the valve and rotatable relative to the valve about a rotation axis that extends in a direction different from the advancement and retreat of the valve, wherein the valve can be advanced and retreated in the advancement and retreat direction by rotating the operating portion about the rotation axis as the rotation center, thereby closing or opening the flow path.

2. A manual gas cutter as described in claim 1, wherein the operating part is rotatable between a first position in which the valve closing part closes the flow path and a second position in which the valve closing part opens the flow path, and the distance from the rotation shaft to the upper end of the cylinder part when the operating part is located at the first position is shorter than the distance from the rotation shaft to the upper end of the cylinder part when the operating part is located at the second position.

3. The manual gas cutter as described in claim 2, wherein the operating part has a first side portion facing the cylinder part in the forward / backward direction when the operating part is located at the first position, and a second side portion facing the upstream side in the oxygen flow direction when the operating part is located at the first position, and when the operating part rotates from the first position to the second position, the operating part rotates from the upstream end of the first side portion while the second side portion is in contact with the upper end of the cylinder part.

4. The manual gas cutter according to claim 2, wherein the cutting oxygen valve is provided with a biasing member which biases the valve in the forward and backward directions, the operating part is rotatable in a second rotational direction opposite to a first rotational direction from the first position to the second position, and when the operating part located at the first position rotates in the second rotational direction, the valve closing part opens the flow path, and the operating part rotated in the second rotational direction is rotated in the first rotational direction by the biasing member.

5. The manual gas cutter according to claim 1, wherein the operating portion is provided with a trigger protruding in a direction away from the rotation shaft.

6. The manual gas cutter according to claim 1, wherein the operating portion is rotatable about a rotation axis extending in the forward and backward directions.

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