Rocking plate cutting device and rocking plate cutting method

Abstract

The present invention provides a riser cutting device and method that can appropriately supply flame-forming gas used when cutting various risers, thereby enabling efficient cutting of risers. [Solution] A riser cutting device that automatically cuts risers attached to a casting when molten metal is poured into a mold to manufacture a casting comprises a cutting torch that emits a flame to preheat and cut the riser, a gas supply unit that supplies flame-forming gas to the cutting torch, a moving device that moves the cutting torch, and a control unit that controls the moving device and the gas supply unit to cause the cutting torch to preheat and cut the riser. The control unit controls the flow rate of at least a portion of the flame-forming gas supplied to the cutting torch according to the diameter and material of the riser.

Description

Technical Field

[0001] The present invention relates to a riser cutting device and a riser cutting method for cutting a riser attached to a casting.

Background Art

[0002] Castings are manufactured by pouring molten metal into a mold. In order to prevent casting defects such as shrinkage cavities generated in the product due to the solidification shrinkage of the molten metal, a riser for supplying molten metal to the product part of the casting may be provided.

[0003] The riser is cut using a burner or the like after the molten metal has solidified. However, manual operation requires skill and takes a lot of time, so a riser cutting device (robot) for automatically cutting the riser has been proposed (for example, Patent Document 1).

[0004] The riser cutting device of Patent Document 1 includes a gas cutting torch, a moving device for moving the cutting torch, and a control device for controlling the moving operation of the moving device.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, when cutting the riser, gas is supplied to the gas cutting torch to form a flame for preheating the riser and a flame for cutting. However, Patent Document 1 only describes the operation control of the riser cutting device and does not describe the gas for flame formation. When actually cutting the riser with a riser cutting device, expensive gas may be used, and it is required to appropriately supply the gas for flame formation to various risers and efficiently cut the riser.

[0007] The present invention aims to provide a riser cutting device and a riser cutting method that can appropriately supply flame-forming gas used when cutting various risers, and can efficiently cut risers. [Means for solving the problem]

[0008] The present invention provides the following means (1) to (14).

[0009] (1) A riser cutting device that automatically cuts off risers attached to a casting when molten metal is poured into a mold to manufacture a casting, A cutting torch that emits a flame to preheat and cut the riser, A gas supply unit that supplies the gas that forms the flame to the cutting torch, A moving device for moving the cutting torch, A control unit that controls the moving device and the gas supply unit to cause the cutting torch to preheat and cut the riser, It has, The riser cutting apparatus is characterized in that the control unit controls the flow rate of at least a portion of the gas that forms the flame supplied to the cutting torch according to the diameter and material of the riser.

[0010] (2) The gas supply unit comprises a gas supply source that supplies the gas that forms the flame, a gas flow path that guides the gas that forms the flame from the gas supply source to the cutting torch, and a flow rate controller provided in the gas flow path. The surge cutting apparatus according to (1), characterized in that the control unit gives a flow rate control command to the flow rate controller, causing the flow rate controller to control the flow rate of at least a portion of the gas that forms the flame.

[0011] (3) The casting is made of an iron-based material, and the gas that forms the flame includes fuel gas, preheating oxygen, and cutting oxygen. The flame includes a preheating flame for preheating the riser and a cutting flame for cutting the riser. The cutting torch forms the preheating flame by supplying the fuel gas and preheating oxygen from the gas supply unit, and forms the cutting flame by supplying cutting oxygen in addition to the fuel gas and preheating oxygen from the gas supply unit. The riser cutting apparatus according to (1), characterized in that the control unit controls the flow rate of the fuel gas and preheated oxygen supplied to the cutting torch according to the diameter and material of the riser.

[0012] (4) The gas supply unit is A fuel gas supply source that supplies the aforementioned fuel gas, A preheating oxygen supply source that supplies the aforementioned preheating oxygen, A cutting oxygen supply source that supplies the cutting oxygen, A first gas passage, a second gas passage, and a third gas passage that guide the fuel gas, preheated oxygen, and cutting oxygen from the fuel gas supply source, the preheated oxygen supply source, and the cutting oxygen supply source to the cutting torch, respectively, A regulator is provided in the first gas passage, the second gas passage, and the third gas passage, which adjusts the supply pressure of the fuel gas, the preheated oxygen, and the cutting oxygen, respectively. A flow controller is provided in the first gas flow path and the second gas flow path, which controls the flow rates of the fuel gas and the preheated oxygen, respectively. It has, The riser cutting apparatus according to (3), characterized in that the control unit gives a flow rate control command to the flow rate controller to control the flow rates of the fuel gas and the preheated oxygen.

[0013] (5) The surge cutting device according to (2) or (4), characterized in that the flow rate controller is a mass flow controller.

[0014] (6) The riser cutting apparatus according to (3) or (4), characterized in that the fuel gas is a mixed gas of hydrogen gas and hydrocarbon gas.

[0015] (7) The cutting torch has a nozzle that emits a flame. The nozzle has a central flow path to which the cutting oxygen is supplied, and an outer peripheral flow path formed around the central flow path and to which the fuel gas and the preheating oxygen are supplied. The hot flash cutting device according to (3) or (4), characterized by this.

[0016] (8) The moving device has a mechanism part having an articulated structure and a driving part that drives the mechanism part. The hot flash cutting device according to (I), characterized by this.

[0017] (9) The mechanism part has a head part to which the cutting torch is attached. The head part is configured such that the angle of the tip of the cutting torch can be freely set. The control unit controls the head part to perform a swinging operation during the preheating. The hot flash cutting device according to (8), characterized by this.

[0018] (10) A hot flash cutting method for automatically cutting the hot flash attached to a casting when a molten metal is poured into a mold to produce a casting. A step of supplying a gas for forming a preheating flame from a gas supply unit to a cutting torch to form the preheating flame and preheating the hot flash. A step of supplying a gas for forming a cutting flame from the gas supply unit to the cutting torch to form the cutting flame and cutting the hot flash. It has A hot flash cutting method characterized by controlling at least part of the flow rate of the gas for forming the preheating flame and the gas for forming the cutting flame supplied to the cutting torch according to the diameter and material of the hot flash.

[0019] (11) The control of at least part of the flow rate of the gas for forming the preheating flame and the gas for forming the cutting flame is performed by a mass flow controller. The hot flash cutting method according to (10), characterized by this.

[0020] (12) The casting is made of an iron-based material, and the preheating flame is formed by supplying fuel gas and preheating oxygen to the cutting torch from the gas supply unit, and the cutting flame is formed by supplying cutting oxygen in addition to the fuel gas and preheating oxygen to the torch from the gas supply unit, The method for cutting a riser according to (10), characterized in that the flow rates of the fuel gas and preheated oxygen supplied to the cutting torch are controlled according to the diameter and material of the riser.

[0021] (13) The method for cutting a riser according to (12), characterized in that the flow rate of the fuel gas and preheated oxygen supplied to the cutting torch is controlled by a mass flow controller.

[0022] (14) The method for cutting a riser according to any one of (10) to (13), characterized in that the fuel gas is a mixed gas of hydrogen gas and hydrocarbon gas. [Effects of the Invention]

[0023] According to the present invention, a riser cutting device and a riser cutting method are provided that can appropriately supply flame-forming gas used when cutting various risers, and can efficiently cut risers. [Brief explanation of the drawing]

[0024] [Figure 1] This is a side view showing a surge cutting device according to one embodiment of the present invention. [Figure 2] This is a cross-sectional view showing an example of the structure of a cutting torch used in one embodiment of the present invention, and a state in which a preheating flame and a cutting flame are formed on the cutting torch. [Figure 3] This is a diagram showing an example of a gas supply unit used in one embodiment of the present invention. [Figure 4] This diagram shows a casting with the riser still attached, placed on a table, with a cutting torch positioned at the cutting point of the riser using a moving device. [Figure 5] Figure 1 is a block diagram showing the control unit of the surge cutting device. [Figure 6] This flowchart shows an example of the control flow for surge cutting. [Figure 7] Figure 6 is a schematic diagram showing the position of the cutting torch in each step of the process. [Modes for carrying out the invention]

[0025] Embodiments of the present invention will be described below with reference to the attached drawings. The riser cutting device (robot) according to this embodiment automatically cuts the riser that accompanies the casting when molten metal is poured into a mold for casting. The metal material used for casting (the metal material that makes up the molten metal poured into the mold) is not particularly limited, but iron-based materials such as cast steel are examples.

[0026] Figure 1 is a side view showing a riser cutting device according to one embodiment of the present invention. The riser cutting device 10 of this embodiment is shown as an example of cutting risers when casting iron-based materials such as cast steel, and includes a cutting torch 1, a gas supply unit 2 that supplies gas to the cutting torch 1, a moving device 3 that moves the cutting torch, and a control unit 4.

[0027] The cutting torch 1 emits a flame F to preheat or cut the riser. When preheating the riser, a preheating flame (hereinafter referred to as the preheating flame) is formed, and when cutting the riser, a cutting flame (hereinafter referred to as the cutting flame) is formed.

[0028] When cutting risers made of iron-based materials, fuel gas, preheating oxygen, and cutting oxygen are used as the gases that form the flame, and a cutting torch 1 is used that has a nozzle 61 with a structure such as the one shown in Figure 2, which radiates a flame from its tip. The nozzle 61 of the cutting torch 1 has a central channel 62 and an outer channel 63 around it. Cutting oxygen is supplied to the central channel 62, and fuel gas and preheating oxygen are supplied to the outer channel 63. As shown in Figure 2(a), a preheating flame 66 is formed when fuel gas 64 and preheating oxygen 65 are supplied to the outer channel 63, and as shown in Figure 2(b), a cutting flame 68 is formed when cutting oxygen 67 is further supplied to the central channel 62 in addition to these, and the riser 71 is cut. In other words, the riser 71 is preheated by the preheating flame 66 formed by the fuel gas 64 and preheating oxygen 65, and then a cutting flame 68 is formed when a large flow rate of cutting oxygen 67 is supplied in addition to these, and an oxidation reaction proceeds at the cutting position of the riser 71, cutting the riser 71.

[0029] As fuel gas, city gas, acetylene gas, propane gas, and a mixture of hydrogen gas and hydrocarbon gas can be used. As an example of a mixture of hydrogen gas and hydrocarbon gas, a mixture of hydrogen gas and ethylene gas can be given. The ratio (volume ratio) of hydrogen gas in a mixture of hydrogen gas and a hydrocarbon gas such as ethylene gas may be 30 to 70 vol%, for example, 60 vol%.

[0030] The gas supply unit 2 includes a gas supply source for supplying gas, a gas flow path for guiding gas from the gas supply source to the cutting torch 1, a regulator for adjusting the gas pressure, and a mass flow controller provided in the gas flow path. When cutting a riser made of iron-based material, for example, as shown in Figure 3, the gas supply unit 2 includes a fuel gas supply source 81, a preheating oxygen supply source 82, and a cutting oxygen supply source 83, and gas flow paths 84, 85, and 86 are connected to the fuel gas supply source 81, the preheating oxygen supply source 82, and the cutting oxygen supply source 83, respectively. Regulators 87, 88, and 89 for adjusting the gas pressure are provided in the gas flow paths 84, 85, and 86, respectively, and solenoid valves 90, 91, and 92 are provided downstream of them, respectively. In addition, mass flow controllers 93 and 94 are provided as flow rate controllers downstream of the solenoid valves 90 and 91 in the gas flow path 84 that supplies fuel gas and the gas flow path 85 that supplies preheating oxygen. Gas passages 84, 85, and 86 are connected to the cutting torch 1. In this example, the cutting oxygen flows at a high flow rate, so flow rate control by a mass flow controller is not applicable. However, if conditions permit, a flow controller such as a mass flow controller may be installed in the cutting oxygen passage.

[0031] The moving device 3 allows the cutting torch 1 to move freely in three-dimensional space. In the example shown in Figure 1, the moving device 3 includes a multi-jointed mechanism 11 and a drive unit 12 that drives the mechanism 11.

[0032] The mechanism 11 includes a base 21 that travels along the transport guide 31, a rotating part 22 rotatably connected to the base 21, a first arm 23 connected to the rotating part 22 via a first joint 26, a second arm 24 connected to the first arm 23 via a second joint 27, and a head part 25 connected to the second arm 24 via a rotating shaft 28 and a third joint 29. The cutting torch 1 is attached to the head part 25. The cutting torch 1 can be freely moved in three-dimensional space as the base 21 travels along the transport guide 31, the rotating part 22 rotates, the first arm 23 and the second arm 24 rotate relative to the first joint 26 and second joint 27, respectively, and the head part 25 rotates on the rotating shaft 28 and rotates relative to the third joint 29.

[0033] Furthermore, in the mechanism 11, the head portion 25 can be freely angled due to the presence of the rotation axis 28 and the third joint portion 29, allowing the angle of the tip of the cutting torch 1 to be freely set. This makes it possible to achieve extremely high operability of the cutting torch 1 when preheating and cutting the riser. For example, when preheating the riser, the head portion 25 can be swung, as will be described later, enabling efficient preheating.

[0034] The drive unit 12 drives the mechanism unit 11, causing the base unit 21 to travel on the transport guide 31, rotating the rotating unit 22, rotating the first arm 23 and the second arm 24 relative to the first joint 26 and the second joint 27, respectively, and rotating the head unit 25 around the rotation axis 28, causing it to rotate relative to the third joint 29. The drive unit 12 has multiple motors provided at appropriate positions to perform these drives. In Figure 1, for convenience, the drive unit 12 is shown as a single element.

[0035] In the moving device 3, the drive unit 12 drives the mechanism unit 11, allowing the cutting torch 1 to be moved freely. Figure 4 shows the state in which the cutting torch 1 has been moved by the moving device 3 to a position to cut the riser 71 on a casting 72 that is placed on a table 70 with the riser 71 still attached.

[0036] The control unit 4 consists of a computer and controls the drive unit 12 so that the mechanism unit 11 performs the desired operation, as well as the supply of gas to the cutting torch 1. As shown in Figure 5, the control unit 4 comprises a main control unit 41, an input device 42 such as a keyboard or mouse, an output device 43 such as a printer, a display device 44, a storage device 45, an external interface 46, and a bus 47 connecting these to each other. The main control unit 41 has a CPU (central processing unit) 51, RAM 52, and ROM 53. The storage device 45 and ROM 53 store various parameters for the operation of the riser cutting device 10, and also store programs for controlling the operation of the riser cutting device 10. In the control unit 4, the CPU 51 uses the RAM 52 as a work area to execute programs stored in the ROM 53 or storage device 45, thereby controlling various operations of the riser cutting device 10. In this embodiment in particular, the control unit 4 controls the flow rate of at least a portion of the gas supplied to the cutting torch according to the diameter and material of the riser. Flow rate control is performed by giving a flow rate control command to a mass flow controller, which is a flow rate controller installed in the gas flow path, causing the mass flow controller to control the flow rate of at least a portion of the gas. When cutting iron-based materials using fuel gas, preheated oxygen, and cutting oxygen, the flow rates of fuel gas and preheated oxygen are controlled according to the diameter and material of the riser, for example. If the flow rate of cutting oxygen can be controlled, the flow rate of cutting oxygen may also be controlled. Gas flow rate control can be performed, for example, by experimentally determining the optimal gas flow rates for each riser diameter and material, such as the fuel gas flow rate and preheated oxygen flow rate, in advance and storing this data in the storage device 45, and then retrieving the corresponding data when actually cutting the riser.

[0037] The operation control of the surge cutting device 10 by the control unit 4 may be performed by confirming its position using a sensor (not shown), or it may be performed based on coordinates programmed in advance.

[0038] Next, we will describe an example of the control flow for surge cutting using the surge cutting device 10 configured as described above. Figure 6 is a flowchart showing an example of the control flow for riser cutting, and Figure 7 is a schematic diagram showing the position of the cutting torch in each step of Figure 6.

[0039] First, the operation of the riser cutting device 10 is started, and the cutting torch 1 is moved to the ignition position (position A in Figure 7) by the moving device 3 (step ST1).

[0040] Next, at ignition position A, the supply of fuel gas is started from the gas supply unit 2 (fuel gas ON), and the cutting torch 1 is ignited by the ignition device 73 (step ST2). At this time, the control unit 4 gives a command to the mass flow controller 93 for the fuel gas ignition flow rate parameter stored in the memory device 45, and controls the fuel gas flow rate to the ignition flow rate. At this point, the preheating oxygen and cutting oxygen are OFF.

[0041] Next, the moving device 3 moves the cutting torch 1 to the standby position (position B in Figure 7), and the supply of preheating oxygen is started (preheating oxygen ON), forming a preheating flame (step ST3). At this time, the control unit 4 maintains the flow rate of the fuel gas and sends a command to the mass flow controller 94 for the ignition flow rate parameter of the preheating oxygen stored in the memory device 45, controlling the flow rate of the preheating oxygen to the ignition flow rate and forming the initial preheating flame F1 shown in Figure 7. The ignition flow rates of the fuel gas and preheating oxygen are set to a flow rate sufficient to maintain the preheating flame.

[0042] Next, the moving device 3 moves the cutting torch 1 to a position (position C in Figure 7) corresponding to the riser to be cut (for example, riser 71a in Figure 7), and adjusts the preheating flame by controlling the flow rate of fuel gas and preheating oxygen according to the type (diameter and material) of the riser to be cut, thereby preheating the riser (riser 71a) (step ST4). At this time, the control unit 4 selects the parameters corresponding to the riser (for example, riser 71a in Figure 7) from the riser type flow rate parameters of fuel gas and preheating oxygen stored in the storage device 45 for each riser type, and gives the command to the mass flow controllers 93 and 94 to control the flow rate of fuel gas and preheating oxygen to the flow rate corresponding to the riser. Then, the riser is preheated with the adjusted preheating flame F2 shown in Figure 7. At this time, the flow rates of fuel gas and preheating oxygen are set to a flow rate sufficient for preheating for riser cutting according to the type (diameter and material) of the riser to be cut.

[0043] When cutting a riser with a cutting torch, it is necessary to sufficiently preheat the starting point of the cut before cutting, and the preheating should be performed to a temperature at or just before the melting point of the riser. Furthermore, if the riser is cylindrical, for example, even if the flame of the cutting torch is applied to the starting point of the cut, the flame may escape in the circumferential direction, making preheating difficult. In such cases, it is effective to rotate the head unit 25 by the rotation axis 28 using the control unit 4, and rotate it relative to the third joint 29, thereby causing the head unit 25 to oscillate. By performing preheating while the head unit 25 oscillates in this way, the flame can be effectively applied to the starting point of the cut of the riser, and effective preheating can be achieved.

[0044] Next, cutting oxygen is supplied in addition to fuel gas and preheated oxygen to form a cutting flame, and the cutting torch is scanned with the cutting flame applied to the cutting position of the riser to be cut to cut the riser (step ST5). At this time, the control unit 4 gives a command to turn on the cutting oxygen. The supply pressure of the cutting oxygen is set by the regulator 89, and the cutting oxygen is supplied to the cutting torch 1 by opening the solenoid valve 92. A cutting flame F3 is formed by the fuel gas, preheated oxygen and cutting oxygen, and the riser to be cut (for example, riser 71a) is cut by this cutting flame F3.

[0045] The supply pressure of the cutting oxygen is set so that the flow rate is sufficient for the iron-based materials constituting the casting to oxidize and react with the fuel gas. In this embodiment, the flow rate of the cutting oxygen is much higher than that of the preheating oxygen, and therefore flow rate control by a mass flow controller is not applicable. However, if the conditions permit, a flow controller such as a mass flow controller may be installed in the flow path of the cutting oxygen.

[0046] As mentioned above, city gas, acetylene gas, propane gas, and a mixture of hydrogen gas and hydrocarbon gas can be used as fuel gas for preheating and cutting. For example, a mixture of hydrogen gas and ethylene gas can be used as a mixture of hydrogen gas and hydrocarbon gas. The ratio (volume ratio) of hydrogen gas in the mixture of hydrogen gas and hydrocarbon gas may be 30 to 70 vol%, for example, 60 vol%.

[0047] A mixture of hydrogen gas and hydrocarbon gas has a higher flame directional properties and thus a higher thermal energy density compared to city gas, etc., and also emits less radiant heat. This increases the localized heat required for cutting, enabling high-speed, flat cutting. Furthermore, a mixture of hydrogen gas and hydrocarbon gas can reduce the amount of CO2 emitted per unit volume of fuel gas compared to other gases such as city gas. For these reasons, a mixture of hydrogen gas and hydrocarbon gas such as ethylene gas is advantageous as a fuel gas. When using a mixture of hydrogen gas and hydrocarbon gas as a fuel gas, the flow rate is preferably 60 to 240 L / min, and should be set appropriately according to the diameter and material of the riser to be cut.

[0048] After cutting is complete, the cutting oxygen is turned OFF, and the flow rates of the fuel gas and preheating oxygen are controlled to the flow rates at the time of ignition to form the initial preheating flame. The cutting torch is then moved to the retracted position (position D in Figure 7) by the moving device (step ST6). At this time, the control unit 4 controls the flow rates of the fuel gas and preheating oxygen based on the ignition flow rate parameters stored in the memory device 45.

[0049] Subsequently, if there is a riser to be cut (for example, riser 71b in Figure 7), the moving device 3 moves the cutting torch 1 to the position corresponding to the riser to be cut (position E in Figure 7), preheats the riser to be cut in the same manner as in step ST4, and then cuts the riser to be cut in the same manner as in step ST5.

[0050] This process is repeated for each riser present in the casting (product). Once no more risers remain, all gases are turned off, and the riser cutting process is completed.

[0051] When cutting the riser in ST5, it is preferable that the cutting oxygen supplied is started when the riser surface reaches the melting temperature or the temperature just before it reaches, for example, 1550°C, due to preheating in ST4. If the cutting oxygen is supplied too early, a large amount of oxygen will be wasted. The timing of supplying cutting oxygen depends on the riser diameter (cross-sectional area) and material, so it is preferable to know these parameters in advance and program them into the control unit 4. For example, if the material used for casting is high-tensile steel, cutting oxygen is supplied 40 seconds after the start of preheating.

[0052] Traditionally, gas has been supplied to a gas cutting torch to form a flame, which is used to preheat and cut risers. It was common practice to manually adjust the gas supply pressure using a regulator. Furthermore, to ensure sufficient preheating and cutting for various risers, the gas supply pressure was adjusted to a constant value based on the largest diameter riser in the casting (product). However, the amount of fuel gas required for preheating and cutting varies depending on the diameter and material of the riser. Simply maintaining a constant gas supply pressure can lead to excessive gas supply and poor efficiency depending on the riser's diameter and material. In particular, when using a mixture of hydrogen and hydrocarbon gases as fuel, this gas is expensive, and maintaining a constant gas supply pressure results in extremely high gas costs.

[0053] Therefore, the control unit 4 controls the flow rate of at least a portion of the gas supplied to the cutting torch 1 according to the diameter and material of the riser. This allows for the appropriate supply of flame-forming gas used when cutting various types of risers, enabling efficient cutting of the riser.

[0054] Specifically, when cutting risers when casting iron-based materials such as cast steel, as in this embodiment, by controlling the flow rates of fuel gas and preheated oxygen supplied to the cutting torch 1 according to the diameter and material of the riser, these can be appropriately supplied to various types of risers, reducing their usage. Furthermore, cutting oxygen can be supplied during cutting to efficiently cut the riser. In particular, when using a mixture of hydrogen gas and hydrocarbon gas, for example, a mixture of hydrogen gas and ethylene gas, as the fuel gas, this gas is expensive, so by controlling the flow rate in this way and reducing the amount used, the cost of the fuel gas can be greatly reduced.

[0055] Although embodiments of the present invention have been described above, these should be considered merely illustrative and not restrictive. The above embodiments may be omitted, substituted, or modified in various ways without departing from the spirit of the present invention.

[0056] For example, in the above embodiment, an example was shown in which the cutting torch was moved using a multi-joint type moving device as shown in Figure 1, but it is not limited to this. Also, the material to be cast is not limited to iron-based materials. Furthermore, a mass flow controller was used as the flow control device, but it is not limited to this. [Examples]

[0057] In this study, we investigated the amount of gas used when preheating and cutting risers attached to castings (products) after casting iron-based materials such as cast steel, by supplying predetermined gases using both a conventional gas supply method and the gas supply method of the present invention.

[0058] Specifically, a mixture of hydrogen gas and ethylene gas (hydrogen: 60 vol%), preheating oxygen, and cutting oxygen were used as gases for cutting risers. After preheating the risers for 40 seconds with the fuel gas and preheating oxygen, cutting oxygen was added to cut the risers. Carbon steel and alloy steel were used as the iron-based materials constituting the castings. The diameter of the risers was 160 to 240 mm. Regarding gas usage, the amount per unit weight of the mixture of hydrogen gas and ethylene gas (hydrogen: 60 vol%) used to cut castings for a certain period in the factory was compared between the conventional gas supply method and the gas supply method of the present invention. During this period, the number of castings subjected to riser cutting was approximately 5 to 10, and the number of risers per casting was 6 to 30.

[0059] In conventional methods, only the supply pressure of the hydrogen gas and ethylene gas mixture, preheating oxygen, and cutting oxygen was adjusted by a regulator. On the other hand, in the present invention, while the supply pressure is the same as in the conventional method, the flow rate of the hydrogen gas and ethylene gas mixture is further controlled by a mass flow controller within the range of 50 to 200 L / min and the flow rate of preheating oxygen within the range of 50 to 200 L / min, depending on the diameter and material of the riser.

[0060] As a result, it was confirmed that the amount of hydrogen gas and ethylene gas mixed per unit weight when using the method of the present invention was reduced by 22% compared to when using the conventional method. [Explanation of Symbols]

[0061] 1 Cutting Torch 2. Gas supply section 3. Mobile device 4. Control Unit 10. Riser cutting device (robot) 11 Mechanism 12 Drive unit 21 Base section 22 Rotating part 23. First Arm 24. Second Arm 25 Head section 26, 27, 29 Joints 28 rotational axes 31 Conveyor Guide 41 Main Control Unit 42 Input devices 43 Output device 44 Display device 45 Storage device 46 External Interfaces 61 Craters 62 Central channel 63 Outer channel 64 Fuel gas 65 Preheated oxygen 66 Preheating flame (flame for preheating) 67 Cutting oxygen 68. Cutting Flame (Flame used for cutting) 70 tables 71, 71a, 71b riser 72 Cast Iron 81 Fuel gas supply sources 82 Preheating oxygen supply source 83. Cutting oxygen supply source 84, 85, 86 Gas flow path 87, 88, 89 Regulators 93, 94 Mass flow controller (flow rate controller) F flame F1 Initial preheating flame (flame for preheating) F2 Adjusted preheating flame (flame for preheating) F3 Cutting Flame (Flame for Cutting)

Claims

1. A riser cutting device that automatically cuts off risers attached to a casting when molten metal is poured into a mold to manufacture a casting, A cutting torch that emits a flame to preheat and cut the riser, A gas supply unit that supplies the gas that forms the flame to the cutting torch, A moving device for moving the cutting torch, A control unit that controls the moving device and the gas supply unit to cause the cutting torch to preheat and cut the riser, It has, The riser cutting apparatus is characterized in that the control unit controls the flow rate of at least a portion of the gas that forms the flame supplied to the cutting torch according to the diameter and material of the riser.

2. The gas supply unit comprises a gas supply source that supplies the gas that forms the flame, a gas flow path that guides the gas that forms the flame from the gas supply source to the cutting torch, and a flow rate controller provided in the gas flow path. The surge cutting apparatus according to claim 1, characterized in that the control unit provides a flow rate control command to the flow rate controller, causing the flow rate controller to control the flow rate of at least a portion of the gas that forms the flame.

3. The aforementioned casting is made of an iron-based material, and the gas that forms the flame includes fuel gas, preheating oxygen, and cutting oxygen. The flame includes a preheating flame for preheating the riser and a cutting flame for cutting the riser. The cutting torch forms the preheating flame by supplying the fuel gas and preheating oxygen from the gas supply unit, and forms the cutting flame by supplying cutting oxygen in addition to the fuel gas and preheating oxygen from the gas supply unit. The riser cutting apparatus according to claim 1, characterized in that the control unit controls the flow rate of the fuel gas and preheated oxygen supplied to the cutting torch according to the diameter and material of the riser.

4. The aforementioned gas supply unit, A fuel gas supply source that supplies the aforementioned fuel gas, A preheating oxygen supply source that supplies the aforementioned preheating oxygen, A cutting oxygen supply source that supplies the cutting oxygen, A first gas passage, a second gas passage, and a third gas passage that guide the fuel gas, preheated oxygen, and cutting oxygen from the fuel gas supply source, the preheated oxygen supply source, and the cutting oxygen supply source to the cutting torch, respectively, A regulator is provided in the first gas passage, the second gas passage, and the third gas passage, which adjusts the supply pressure of the fuel gas, the preheated oxygen, and the cutting oxygen, respectively. A flow controller is provided in the first gas flow path and the second gas flow path, which controls the flow rates of the fuel gas and the preheated oxygen, respectively. It has, The surge cutting apparatus according to claim 3, characterized in that the control unit provides a flow rate control command to the flow rate controller to control the flow rates of the fuel gas and the preheated oxygen.

5. The surge cutting device according to claim 2 or 4, characterized in that the flow rate controller is a mass flow controller.

6. The riser cutting apparatus according to claim 3 or 4, characterized in that the fuel gas is a mixed gas of hydrogen gas and hydrocarbon gas.

7. The cutting torch has a nozzle that emits a flame, and the nozzle has a central channel to which the cutting oxygen is supplied, and an outer channel formed around the central channel to which the fuel gas and the preheated oxygen are supplied, characterized in that the riser cutting apparatus according to claim 3 or 4.

8. The surge cutting device according to claim 1, characterized in that the moving device comprises a mechanism having a multi-joint structure and a drive unit that drives the mechanism.

9. The mechanism has a head portion to which the cutting torch is attached, and the head portion is configured to allow the angle of the tip of the cutting torch to be freely set. The surge cutting device according to claim 8, characterized in that the control unit controls the head unit to oscillate during preheating.

10. A riser cutting method for automatically cutting risers attached to a casting when molten metal is poured into a mold to manufacture a casting, The process involves supplying gas from the gas supply unit to the cutting torch to form a preheating flame, thereby preheating the riser, The process involves supplying gas from the gas supply unit to the cutting torch to form a cutting flame, thereby forming the cutting flame and cutting the riser, It has, A method for cutting a riser, characterized by controlling the flow rate of at least a portion of the gas that forms the preheating flame and the gas that forms the cutting flame supplied to the cutting torch, according to the diameter and material of the riser.

11. The method for cutting a riser according to claim 10, characterized in that the flow rate of at least a portion of the gas that forms the preheating flame and the gas that forms the cutting flame is controlled by a mass flow controller.

12. The casting is made of an iron-based material, and the preheating flame is formed by supplying fuel gas and preheating oxygen to the cutting torch from the gas supply unit, and the cutting flame is formed by supplying cutting oxygen in addition to the fuel gas and preheating oxygen to the cutting torch from the gas supply unit. The method for cutting a riser according to claim 10, characterized in that the flow rates of the fuel gas and preheated oxygen supplied to the cutting torch are controlled according to the diameter and material of the riser.

13. The method for cutting a riser according to claim 12, characterized in that the flow rates of the fuel gas and preheated oxygen supplied to the cutting torch are controlled by a mass flow controller.

14. The method for cutting a riser according to any one of claims 10 to 13, characterized in that the fuel gas is a mixed gas of hydrogen gas and hydrocarbon gas.

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