JP3526942B2 - Gas flow regulator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas adjusting device for adjusting a flow rate of a gas supplied to a gas processing torch. 2. Description of the Related Art In gas processing for cutting or welding a workpiece, a plurality of types of gases are used. For example, in gas cutting, a fuel gas such as acetylene gas or LPG and a supporting gas such as oxygen gas are mixed and injected from a crater attached to a torch and burned, and the workpiece is preheated by the formed flame. At the same time, cutting oxygen is injected to cut the material to be cut. [0003] The amount of gas supplied to the torch is defined by the pressure difference between the supply side (primary side) and the discharge side (secondary side) at the minimum cross section of the torch (the minimum cross section of the crater). You. In the gas processing torch, the flow rate of the fuel gas that can be preheated most effectively for each crater and the flow rate of the supporting gas corresponding to the flow rate of the fuel gas are set. [0004] The control of the gas flow rate in the gas processing torch is carried out by maintaining the supply pressure of the gas pipe at a position at a predetermined distance from the inlet of the torch or at a distance from the torch, or changing the pressure appropriately. It is generally done. On the other hand, the flow rate of a gas disposed in a gas pipe is detected, and when the flow rate changes from a preset flow rate, a signal corresponding to the change in the flow rate is generated to change the opening degree of the valve. Adjustable gas flow controllers have been developed. The gas flow adjusting device includes a control unit that generates a command signal corresponding to a set gas flow rate, a detection unit that detects a current gas flow rate to generate a detection signal, and a comparison unit that compares the detection signal with the command signal. , And an adjustment unit including a valve unit. [0006] In the gas flow control device, even if the primary pressure (inlet pressure) or the secondary pressure (outlet pressure) fluctuates, a predetermined constant flow rate is maintained regardless of the fluctuation. Can be done. [0007] When an equivalent gas is supplied to a large number of gas processing torches at a time, the gas flows in a method of controlling the gas flow rate by the gas supply pressure to the gas processing torch. Even if the distance from the main pipe to each torch is equal, there is a problem that it is difficult to make the flow rate of gas the same because the supply pressure changes for each torch. Further, the method of controlling the gas flow rate using a pressure regulator and a float type flow meter has a problem in that when using gases having different molecular weights, a flow meter corresponding to the molecular weight of the gas must be used. When the torch is a gas cutting torch,
When the crater number is changed according to the thickness of the material to be cut, that is, when the crater mounted on the torch is replaced, the flow rate of each of the plurality of gases (supply pressure of each gas) according to the mounted crater Has to be set again, which causes a problem that the operation becomes complicated. The above-mentioned problems can be avoided by using the above gas flow adjusting device. However, this gas flow control device requires one control unit corresponding to one control unit. For this reason, when a large number of torches are used at one time, a control unit for controlling the number of torches times the number of gases supplied to the torches is required, which causes a problem of a significant cost increase. It is an object of the present invention to accurately control the flow rate of gas supplied to a large number of torches and to finely adjust the gas flow rate in accordance with the function of the torch without significantly increasing the cost. It is an object of the present invention to provide an apparatus for adjusting a gas flow rate that can perform the above. [0011] In order to solve the above-mentioned problems, a gas flow control device according to the present invention is provided with a plurality of types of craters selectively mounted and supplied with a supporting gas and a fuel gas. A plurality of gas processing torches for performing gas processing on the workpiece by igniting while injecting the gas from the crater, and a preset gas connected to a supply side of a supporting gas and a fuel gas for each of the plurality of gas processing torches. Receives a command signal corresponding to the flow rate, compares the command signal with a detection signal that detects the current gas flow rate, and presets the current gas flow rate when the current gas flow rate fluctuates from a preset gas flow rate value A plurality of constant flow rate elements for adjusting the gas flow rate, a storage unit for storing flow rate information of the supporting gas and the fuel gas corresponding to the crater attached to the gas processing torch, and a crater for specifying the number of the crater A count designation section, a high / low setting section for setting a flame formed at the crater to a strong preheating flame or a weak preheating flame, and a mixing ratio fine adjustment setting section for setting a flame to be formed at the crater to an oxidizing flame or a carbonized flame. Controlling means having a crater number designating section, by designating the crater number attached to the gas processing torch by the crater number designation section, and selectively operating the high / low setting section or the mixture ratio fine adjustment setting section. To select the properties of the flame, and to provide the selected supporting gas and fuel gas flow rate information to the plurality of constant flow elements connected to the supporting gas and fuel gas supply sides for each of the plurality of gas processing torches. It is configured to transmit. In the above gas flow adjusting device, a plurality of types of craters,
For example, a gas processing torch (hereinafter simply referred to as a “torch”) to which a gas cutting crater is selectively mounted receives a command signal corresponding to a preset gas flow rate on the side of a supporting gas and a fuel gas, and receives this command signal and Connects a constant flow element that adjusts the current gas flow rate to a preset gas flow rate when the current gas flow rate fluctuates from a preset gas flow rate by comparing a detection signal that detects the current gas flow rate. Then, a command signal corresponding to a gas flow rate set in advance for each gas is simultaneously transmitted from the control means to a plurality of constant flow rate elements attached to each torch for each gas, whereby a plurality of constant flow elements are provided by one controller. The flow element can be controlled. For this reason, it is possible to accurately control the gas flow rate for the plurality of torches without significantly increasing the cost. In particular, the control means includes a storage unit for storing flow rate information of the supporting gas and the fuel gas corresponding to the crater attached to the torch, a crater number designation unit for designating the number of the crater, Since it has a high / low setting unit for setting the flame to be formed as a strong preheating flame or a weak preheating flame, and a mixing ratio fine adjustment setting unit for setting the flame to be formed at the crater to an oxidizing flame or a carbonized flame. By operating the crater number designating section to designate the crater number attached to the torch, the standard supporting gas and fuel gas flow rates to be supplied to the crater are read from the storage section and controlled. , A neutral flame of standard flow rate can be formed. By operating the high / low setting unit to designate a strong preheating flame or a weak preheating flame, the flow rates of the supporting gas and the fuel gas are increased or decreased to form a strong preheating flame or a standard preheating flame. Can be controlled as follows. Further, by operating the mixing ratio fine adjustment, it is possible to control so as to form an oxidizing flame or a carbonizing flame by increasing or decreasing the flow rate of one of the supporting gas and the fuel gas. An embodiment of the gas flow rate adjusting device will be described below with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a gas cutting device using a plurality of gas cutting torches to which a gas flow adjusting device according to the present embodiment is applied, FIG. 2 is a block diagram of a control system for adjusting a gas flow, and FIG. It is a block diagram explaining the schematic structure of a flow element. The gas flow adjusting device according to the present invention relates to a device for adjusting a flow rate of a gas supplied to a gas processing torch such as a gas cutting torch or a gas welding torch. It is effective when applied to an apparatus. Hereinafter, a case where the gas flow rate adjusting device is applied to a gas cutting device using a plurality of gas cutting torches (torches) will be described. As the gas cutting device, any cutting device equipped with a plurality of torches, such as a numerically controlled cutting device, a cutting device having optical copying means, and a linear cutting device, can be used. As shown in FIG. 1, a gas cutting device to which the gas flow adjusting device according to the present invention can be applied has a bogie 2 movably arranged on a pair of rails 1 laid in parallel. ing. The carriage 2 has a saddle 2a on which a traveling motor (not shown) is arranged, and a cross garter 2b arranged in a direction orthogonal to the laying direction of the rail 1, and a cross rail 3 is provided along the cross garter 2b. Have been. Further, a plurality of torches 4a to 4e each having a crater 5 selected in advance are arranged on the cross rail 3. Each of the torches 4a to 4g is placed on the cross garter 2b.
A pipe 6 for supplying a fuel gas to the pipe 4e, a pipe 7 for supplying a supporting gas serving as a supporting gas, and a pipe 8 for supplying cutting oxygen are respectively arranged. Each of the pipes 6 to 8 and each of the torches 4a to 4e.
Are connected by hoses 9a to 9c. Each of the pipes 6 to 8 has a pressure regulator 10 to 12 for adjusting a supply pressure.
Is provided. Therefore, the pressure of each gas supplied to each of the torches 4a to 4e can be set independently by operating the respective pressure regulators 10 to 12. A control device A (see FIG. 2) which constitutes a gas flow rate adjusting device is provided on the cross garter 2b, and a fuel gas and a supporting gas supply side in each of the torches 4a to 4e is provided. Solenoid valves 13a-13c between each torch 4a-4e
Is provided with the constant flow element B. First, the configuration of the control device A will be described with reference to FIG. The controller A controls the standard flow rates of the fuel gas and the supporting gas supplied to the crater 5 attached to the torches 4a to 4e (necessary for forming a neutral flame when preheating the material to be cut within a standard time). Storage unit 21 for storing information of various gas flow rates)
And an arithmetic unit 22. Control device A
The crater number designating part 23 for specifying the crater number, changing the mixing ratio of the fuel gas and the supporting gas to generate a signal to set the preheating flame from the neutral flame to the oxidizing flame or the carbonizing flame is finely adjusted. The setting unit 24, the override setting unit 25 that generates a signal to increase or decrease the flow rate without changing the property of the preheating flame selected by the operation in accordance with the operation of the mixing ratio fine adjustment setting unit 24, suitable for cutting. In order to shorten the preheating time at the time of low and cutting when the standard flow rate of fuel gas and supporting gas is given, increase the flow rate of fuel gas and supporting gas in the preheating flame from the standard flow rate, or change the properties of the preheating flame to oxidizing flame. A high / low setting unit 26 is provided for generating a signal for selecting a high state to be set to a predetermined value and appropriately setting these gases to appropriate values. A command signal for commanding the flow rates of the fuel gas and the supporting gas is generated independently from the arithmetic unit 22, the command signal for the fuel gas is output via an amplifier 27a, and the command signal for the supporting gas is It is configured to be able to output via the amplifier 27b. The crater number designation section 23, the mixture ratio fine adjustment setting section 24, and the high / low setting section 26 are constituted by a push button switch, a keyboard, and the like provided on a control panel in which the control device A is stored. The unit 25 is constituted by a volume provided on the control panel. The control device A is a higher-level control device such as a numerical control device 29 so as to be applicable to, for example, a numerical control cutting device.
And a switching section 28 for switching between an input signal from the crater number designation section 23 and an input signal from the numerical controller 29. In this case, a signal specifying the crater number is input from the numerical control device 29 to the control device A. The numerical controller 29 is configured to issue a setting command to the mixing ratio fine adjustment setting unit 24 and the high / low setting unit 26. A signal distribution unit C is arranged between the control device A and the individual constant flow elements B. The signal distribution unit C has a function of amplifying the command signal output from the control device A and distributing the command signal to the torches 4a to 4e. An amplifier corresponding to the number of supplied gases is provided. In this embodiment, the number of torches is five, and the number of gases whose flow rate is to be adjusted is two of fuel gas and supporting gas.
Because of the type, the signal distribution unit C is provided with five amplifiers 31a and 31b corresponding to each gas. The installation position of the signal distribution unit C is not particularly limited. For example, the signal distribution unit C can be installed on a control panel in which the control device A is stored. Alternatively, an independent control panel can be provided and installed on the cross garter 2b. Is also possible. Next, the configuration of the constant flow element B will be described with reference to FIG. The constant flow element B includes a pipe 6 for supplying a fuel gas, a pipe 7 for supplying a supporting gas, and torches 4a to 4e.
Are arranged in the paths of the hoses 9a and 9b that connect the gas to the gas supply line, so that the gas flow rate set in response to the command signal from the control device A can be maintained. The constant flow element B is provided with a passage 41 having a main passage 41a through which most of the gas passes and a bypass passage 41b from the main passage 41a.
Is arranged. The passage 41 is connected to hoses 9a and 9b for fuel gas or supporting gas. A self-heating resistor 43 is provided in the bypass passage 41b.
a and 43b are wound and connected to the bridge circuit 44, respectively. The bridge circuit 44 is connected to a comparison operation unit 46 via an amplification circuit 45. This comparison operation unit 46
Is connected to either the amplifier 31a or the amplifier 31b provided in the signal distribution unit C, and the command signal of the gas flow generated from the controller A is transmitted as the voltage Vs. As the valve 42, a valve whose opening can be adjusted is used. Various types of valves that can adjust the opening degree are provided.
A valve is used that causes distortion in the opening adjustment section 47 in accordance with the voltage output from 46, and that can adjust the opening in accordance with the distortion. In the constant flow element B configured as described above,
When the command signal transmitted from the control device A is input to the comparison operation unit 46, a voltage corresponding to the command signal is generated from the operation unit 46, distorting the opening adjustment unit 47, and the distortion causes the valve
The opening of the main passage 41a and the bypass passage 41b
Gas flow occurs. In the bypass passage 41b, the self-heating type resistor 43
Heat is applied to the gas flowing from a. afterwards,
The temperature of the flowing gas is detected by a self-heating resistor 43b arranged at a predetermined distance from the self-heating resistor 43a, and a detection signal is sent from the bridge circuit 44 to the amplification circuit.
The voltage is transmitted as voltage Vd to the comparison operation unit 46 via 45.
Then, the command signal Vs and the detection signal V
is compared with d, and an operation signal corresponding to the difference between these signals is output to the opening degree adjustment unit 47. The opening degree adjuster 47 increases or decreases the distortion in response to the operation signal, and the opening degree of the valve 42 is adjusted accordingly, so that the gas flows at the flow rate set by the controller A through the passage 41. If the flow rate of the gas flowing through the passage 41 changes even though the command signal Vs from the control device A does not change, the flow rate of the bypass passage 41b also changes with this change. Therefore, a change occurs in the temperature of the gas detected by the self-heating resistor 43b, and the detection signal Vd changes.
Then, an operation signal for returning the change to the original state is transmitted from the comparison operation unit 46 to the opening adjustment unit 47, and the valve 42
Adjust the opening of. By the above operation, the gas flow rate is kept constant. Next, a procedure for adjusting the flow rate of the gas supplied to the torches 4a to 4e by the gas flow rate adjusting device according to the present embodiment will be described. First, a crater 5 according to the thickness of the material to be cut is mounted on the torches 4a to 4e, and a crater number setting unit of the control device A is set.
23 or the upper numerical controller 29 inputs the count information corresponding to the count of the crater 5. At the same time, the properties of the preheating flame at the start of cutting are set according to the case of starting to cut the material to be cut from the end face or the case of starting to cut from the surface. That is, it is necessary to perform piercing when starting to cut the material to be cut from the surface, and by setting the high / low setting unit 26 to the high state, the flow rate of each gas is increased from the standard flow rate given in the low state. Perform piercing with a preheating flame that has been turned into an oxidizing flame, after piercing is completed, set to the low state, continue cutting with the preheating flame of the optimal standard flow rate at the time of cutting, and adjust to the standard flow given in the low state On the other hand, if it is deemed necessary according to the condition of the surface of the material to be cut or other conditions, the property of the preheating flame is set to oxidizing flame or carbonization flame by the mixing ratio fine adjustment setting unit 24 and the override setting unit 25 is set. Set the degree of oxidizing flame or carbonizing flame. In the case where the material to be cut is started from the end face and there is no possibility that the oxide scale or the like adhering to the surface of the material will adversely affect the preheating, it is necessary to increase the flow rate of the gas or to oxidize the gas. The crater count setting section without flame
Perform only 23 operations. The operation of the crater count setting unit 23 causes the torch 4
When information of the crater corresponding to the crater 5 attached to a to 4e is input, the flow rate information of the fuel gas and the supporting gas stored in the storage unit 21 is transmitted to the calculation unit 21. The calculation unit 21 performs a calculation by integrating the transmitted flow rate information and the setting information from the other setting units 24 to 26, and generates a fuel gas command signal and a supporting gas command signal. The command signal of the fuel gas generated from the control device A is amplified by the amplifier 27a and input to a plurality of amplifiers 31a provided in the distribution unit C, and the command signal of the supporting gas is similarly amplified by the amplifier 27b. The signal is input to a plurality of amplifiers 31b provided in the distribution unit C. That is, the command signal for each gas generated by the control device A is distributed to the same and a plurality of command signals in the distribution unit C. Each amplifier 31 provided in the distribution unit C
a, 31b are constant flow elements B corresponding to the respective torches 4a to 4e.
And transmits a command signal Vs corresponding to the fuel gas and the supporting gas to these constant flow elements B. Therefore, when the solenoid valves 13a and 13b attached to the torches 4a to 4e are opened, the fuel gas having the flow rate set by the control device A and the fuel supporting from the preheating holes of the crater 5 attached to each of the torches 4a to 4e. Gas escapes. By igniting in this state, a preheating flame can be formed. In the above embodiment, the case where the flow rates of the fuel gas and the supporting gas are adjusted in order to form the preheating flame in the crater 5, but the flow rate of the cutting oxygen can be adjusted by the same mechanism. Of course it is possible. As described in detail above, in the gas flow adjusting device according to the present invention, a constant flow element is provided on the supply side of different gases of a torch to which a plurality of types of gas cutting craters are selectively mounted. By simultaneously transmitting a command signal corresponding to a gas flow rate preset for each gas from the control means to the constant flow rate element, a single control device can control a plurality of constant flow rate elements. I can do it. For this reason, it is possible to accurately control the gas flow rate for the plurality of torches without significantly increasing the cost. By operating the crater number designation section to designate the crater number attached to the torch, the standard flow rates of the supporting gas and fuel gas to be supplied to the crater are read out from the storage section and controlled. By doing so, a neutral flame can be formed. By operating the high / low setting unit to designate a strong flame or a weak flame, the flow rate of the supporting gas and the fuel gas is increased or decreased to control the formation of a strong flame or a weak flame. The control can be performed so as to form a neutral flame without operating the / low setting section. Furthermore,
By manipulating the fine adjustment of the mixture ratio, it is possible to increase or decrease the flow rate of one of the supporting gas and the fuel gas, thereby controlling to form an oxidizing flame or a carbonizing flame.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a gas cutting device using a plurality of gas cutting torches to which a gas flow adjusting device according to the present embodiment is applied. FIG. 2 is a block diagram of a control system for adjusting a gas flow rate. FIG. 3 is a block diagram illustrating a schematic configuration of a constant flow element. [Description of Signs] A control device B constant flow element C distribution unit 1 rail 2 trolley 3 cross rail 4a-4e torch 5 crater 6-8 piping 9a-9c hose 10-12 pressure regulators 13a-13c solenoid valve 21 storage unit 22 arithmetic unit 23 crater number designation unit 24 mixture ratio fine adjustment setting unit 25 override setting unit 26 high / low setting unit 27a, 27b amplifier 28 switching unit 29 numerical control devices 31a, 31b amplifier 41 passage 41a main passage 41b bypass passage 42 valve 43a, 43b Self-heating type resistor 44 Bridge circuit 45 Amplifier circuit 46 Comparison operation unit 47 Opening adjustment unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-350705 (JP, A) JP-A-7-16754 (JP, A) JP-A-6-83162 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) B23K 10/00 502 B23K 10/00 504

Claims (1)

(57) Claims 1. A plurality of types of craters are selectively mounted, and the supplied supporting gas and fuel gas are injected from the crater and ignited to perform gas processing on a workpiece. And a command signal corresponding to a preset gas flow rate connected to the supply side of the supporting gas and fuel gas for each of the plurality of gas processing torches, and the command signal and the current gas flow rate A plurality of constant flow elements that adjust the current gas flow rate to a preset gas flow rate when the current gas flow rate fluctuates from a preset gas flow rate value by comparing the detection signal with the detected signal; A storage unit for storing flow rate information of the supporting gas and the fuel gas corresponding to the crater attached to the processing torch, a crater number designation unit for designating the number of the crater, and a strong preheating flame or Set for weak preheating flame Control means having a high / low setting unit for setting a flame to be formed at the crater to an oxidizing flame or a carbonizing flame, and a mixing ratio fine adjustment setting unit for setting a flame to be formed at the crater. The number of the attached crater is designated, and the high / low setting section or the mixture ratio fine adjustment setting section is selectively operated to select the property of the flame, and the flow rate information of the selected supporting gas and fuel gas is displayed. An apparatus for adjusting a gas flow rate, wherein the gas flow is transmitted to a plurality of constant flow elements connected to a supply side of a supporting gas and a fuel gas for each of the plurality of gas processing torches.