Flame cutting machine

Abstract

The invention relates to a flame cutting device with a nozzle having an outlet opening for a flame, with a fuel line (12) for supplying a combustible gas to the nozzle, with an oxygen line (14) for supplying oxygen to the nozzle, and with a control device (10) for controlling the supply of the fuel and oxygen to the nozzle. According to the invention, the control device (10) has a first flow controller (16) for controlling the flow in the fuel line (12) and a second flow controller (18) for controlling the flow in the oxygen line (14), as well as a data processing device (20) for controlling the first and second flow controllers (16, 18).

Description

The invention relates to a torch cutting device according to the preamble of claim 1.Torch cutters of the type mentioned at the beginning are widely used in the machining of workpieces. To produce a flame emerging from the nozzle, a gaseous fuel, usually acetylene or propane, is burned by supplying oxygen. The flame usually consists of an inner flame and an outer flame surrounding the inner flame, which has a lower temperature than the inner flame. The inner flame is formed by the combustion of the fuel with the pure oxygen supplied, while the outer flame is formed by the combustion of excess fuel with the ambient oxygen. The outer flame is smaller the more fuel is burned with the supplied oxygen, and it is not present when an excess of oxygen is supplied. The inner flame is used for cutting the workpiece, while the outer flame is usually used for heating the workpiece and for introducing energy into the workpiece. By regulating the supply of the fuel and the oxygen, the power, the size and the shape of the flame and the ratio of inner flame to outer flame can be regulated depending on the desired result. The fuel and the oxygen are supplied under pressure control, optionally corrected by a Venturi nozzle, which is also intended to carry along a suitable amount of fuel with the oxygen flowing through. However, it has been found in practice that the pressure control is not accurate enough for some applications and that its imprecision cannot be compensated by the Venturi nozzle. Readjustment of the flame is therefore usually effected manually by means of control valves which are set manually by the operator. However, such manual readjustment is only possible if the operator can observe the flame. If the flame is poor or not visible, such readjustment is hardly possible reliably.It is therefore an object of the invention to further develop a torch cutting device of the type mentioned at the beginning in such a way that a more precise control is possible.This object is achieved according to the invention by a burning cutter having the features of claim 1. Advantageous further developments of the invention are the subject of the dependent claims.The invention is based on the idea of regulating the quantity of the supplied fuel and the quantity of the supplied oxygen by means of flow regulators, so that the two quantities can be matched to one another as accurately as possible. The two flow controllers are controlled by a processor which expediently has a data memory in that the flow in the fuel line and the flow in the oxygen line are stored as a function of a setpoint value of at least one parameter characterizing the flame. Parameters can be, for example, the performance of the flame, the shape of the flame, the size of the flame and the size ratio of inner to outer flame.Preferably, the control device comprises no further control unit in addition to the first and the second flow controller. The supply of the fuel and of the oxygen is then controlled exclusively by means of the two flow controllers. The invention can be used particularly advantageously when the fuel is hydrogen or a hydrogen mixture. Hydrogen is increasingly used as fuel because it burns without the formation of carbon dioxide. A hydrogen flame is almost invisible, so that it cannot be readjusted manually.The invention is explained in more detail below with reference to an exemplary embodiment schematically shown in the drawing. It shows FIG. 1 is a schematic illustration of a control device for a torch cutting tool.The control device 10 shown in FIG. 1 serves for controlling the supply of a combustion gas such as hydrogen through a fuel line 12 and the supply of oxygen through an oxygen line 14 for generating a flame to a nozzle of a combustion cutting device, which nozzle is not shown in the drawing. The control device has a first flow controller 16 for controlling the flow in the fuel line 12 and a second flow controller 18 for controlling the flow in the oxygen line 14. Furthermore, the control device 10 has a data processing device 20, which in turn has a processor 22 and a data memory 24. The flow values required for reaching the desired values are stored in the fuel line 12 and in the oxygen line 14 in each case for desired values of parameters characterizing the flame. A first sensor 26 measures the flow rate in the fuel line 12 while a second sensor 28 measures the flow rate in the oxygen line 14. Both measured values are transmitted to the data processing device 20.For regulating the flame, the setpoint values for the parameters characterizing the flame, namely the power, the size and the shape of the flame and the ratio of inner flame, which arises as a result of the combustion of the combustion gas by means of the supplied oxygen, and outer flame, which surrounds the inner flame and arises as a result of the combustion of excess combustion gas with oxygen from the environment, are input. The processor 22 then reads out from the data memory 24 the fuel gas and oxygen flows required for reaching the setpoint values and controls the flow controllers 16, 18 accordingly. Monitoring and readjustment takes place via the sensors 26, 28.In summary, the following is to be stated: The invention relates to a flame cutting device having a nozzle which has an outlet opening for a flame, having a fuel line 12 for feeding a combustible gas to the nozzle, having an oxygen line 14 for feeding oxygen to the nozzle and having a regulating device 10 for regulating the feeding of the fuel and of the oxygen to the nozzle. According to the invention, it is provided that the regulating device 10 has a first flow regulator 16 for regulating the flow in the fuel line 12 and a second flow regulator 18 for regulating the flow in the oxygen line 14 and a data processing device 20 for controlling the first and the second flow regulator 16, 18.

Claims

A combustion cutting apparatus having a nozzle having an outlet opening for a flame, having a fuel line (12) for supplying a combustible gas to the nozzle, having an oxygen line (14) for supplying oxygen to the nozzle and having a regulating device (10) for regulating the supply of the fuel and the oxygen to the nozzle, characterized in that the regulating device (10) has a first throughflow regulator (16) for regulating the throughflow in the fuel line (12) and a second throughflow regulator (18) for regulating the throughflow in the oxygen line (14) and a data processing device (20) for controlling the first and the second throughflow regulator (16, 18).Flame cutting device according to Claim 1, characterized in that the data processing device (20) has a data memory (24) in which the throughflow in the fuel line (12) and the throughflow in the oxygen line (14) are stored as a function of a setpoint value of at least one parameter characterizing the flame.The torch according to claim 2, characterized in that the at least one parameter is the performance of the flame.The flame cutting device according to claim 2 or 3, characterized in that the at least one parameter is the shape and / or the size of the flame.A combustion cutting device according to claim 4, characterized in that the shape of the flame comprises the ratio of the inner to outer flame.Torch cutting tool according to one of the preceding claims, characterized in that the control device (10) has no further control unit in addition to the first and second throughflow controllers (16, 18).A fuel cutting device according to any one of the preceding claims, characterised in that the fuel is hydrogen or a hydrogen mixture.Method for regulating the flame of a combustion cutting device, which has a nozzle for the emission of a flame, a fuel line (12) for supplying a combustible gas, in particular hydrogen or a hydrogen mixture, to the nozzle, an oxygen line (14) for supplying oxygen to the nozzle and a regulating device (10) for regulating the supply of the fuel and the oxygen to the nozzle, wherein the regulating device (10) has a data processing device (20), a first throughflow regulator (16) for regulating the throughflow in the fuel line (12) and a second throughflow regulator (18) for regulating the throughflow in the oxygen line (14), and wherein at least one parameter characterizing the flame is regulated by means of the regulating device (10), a processor (22) of the data processing device (20) controls the first flow controller (16) and the second flow controller (18) on the basis of data stored in a data memory (24).Method according to claim 8, characterized in that the at least one parameter is the performance and / or the shape and / or the size of the flame.Method according to claim 9, characterised in that the shape of the flame comprises the ratio of the inner to outer flame.Method according to one of Claims 8 to 10, characterized in that the power and / or the shape of the flame is controlled only by means of the first and the second throughflow regulator (16, 18).

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