JP2018176256A - Water circulation passage of arc processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early and reliably determine obstruction which occurs in a water circulation passage of an arc processing device.SOLUTION: A water circulation passage of an arc processing device, which is formed from an internal water path of a water circulator WC, an approach path 7, an internal water path of a torch WT and a return path 8, comprises: a water pressure adjustment part PD which adjusts a water pressure of the approach path 7 and outputs a water pressure signal Pd; a flow rate detection part FD which detects a flow rate of the return path 8 and outputs a flow rate signal Fd; a flow rate setting part FR which calculates a flow rate setting signal Fr by a predetermined function with the water pressure signal Pd as an input; an alarm determination part AR which outputs an alarm signal Ar when a difference between the flow rate signal Fd and the flow rate setting signal Fr is a predetermined first reference value or more; and a notification part PL which notifies with the alarm signal Ar as an input.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a water circuit of an arc processing apparatus.

  Arc processing apparatuses for welding or cutting metal by arc are widely used. The arc processing apparatus includes an arc welding apparatus for welding by an arc, a plasma welding apparatus for welding by a plasma arc in which the arc is narrowed, and a plasma cutting apparatus for cutting by a plasma arc. Water-cooled torches are often used in these arc processing devices.

  In order to use a water-cooled torch, the arc processing apparatus is provided with a water circuit. The water circulation path has a structure in which water supplied from the water channel inside the water circulator passes through the outward channel, passes through the water channel inside the torch, passes through the return channel, and returns to the water channel inside the water circulator. The water circulator includes a water tank, a pump for circulating water, and a blower for cooling water returned from the return path. Forward and return routes are hoses and the like. The water channel inside the torch is formed by circulating a torch body, a nozzle, an electrode and the like. Each part is cooled by water passing through the water channel inside the torch.

  The water channel inside the torch has a complicated structure to enhance the cooling effect. For this reason, the water channel may be clogged by impurities contained in water. In addition, the nozzles, electrodes and the like provided in the vicinity of the arc generation unit are heated to high temperatures and cause wear and deformation. Because of this, there may be a hole in the water channel and a leak may occur.

  In order to cope with the failure which arose in the above water circulation path, in patent document 1, the sensor which confirms the flow volume of the water circulation path is provided in the last end (return line) of the water circulation path.

Unexamined-Japanese-Patent No. 5-96377

  The appropriate value of the water circulation flow rate has a width. For this reason, it is difficult to set a threshold value to be abnormal even if a flow rate sensor is provided in the return path and the flow rate is detected to make an abnormality determination as in the prior art. Furthermore, if the type of torch is different, the range of the appropriate flow rate changes, which makes it difficult to perform abnormality determination. As a result, in the prior art, there is a problem that it is impossible to determine an abnormality except when the flow rate is extremely reduced.

  So, in this invention, it aims at providing the water circulation path of the arc processing apparatus which can determine the failure which generate | occur | produces in a water circulation path early and reliably.

In order to solve the problems described above, the invention of claim 1 is
A water circulation path of an arc processing apparatus formed of an internal water channel of a water circulator, an outward path, an internal water channel of a torch, and a return path,
A water pressure control unit that adjusts the water pressure in the forward path and outputs a water pressure signal;
A flow rate detection unit that detects a flow rate of the return path and outputs a flow rate signal;
A flow rate setting unit that calculates a flow rate setting signal according to a predetermined function using the water pressure signal as an input;
An alarm determination unit that outputs an alarm signal when the difference between the flow rate signal and the flow rate setting signal is equal to or greater than a predetermined first reference value;
A notification unit that notifies the alarm signal as an input;
And a water circulation path of the arc processing apparatus.

The invention according to claim 2 is a solenoid valve for opening and closing the forward path,
A shutoff determination unit which outputs a shutoff signal when the difference between the flow rate signal and the flow rate setting signal is equal to or greater than a second reference value predetermined to a value larger than the first reference value;
A solenoid valve control unit which receives the shutoff signal as an input and brings the solenoid valve into a shutoff state;
The water circulation path of the arc processing apparatus according to claim 1, further comprising:

The invention according to claim 3 changes the function according to the type of the torch.
It is a water circulation path of the arc processing apparatus of Claim 1 or Claim 2 characterized by the above-mentioned.

  ADVANTAGE OF THE INVENTION According to this invention, the disorder | damage | failure generate | occur | produced in the water circulation path of an arc processing apparatus can be determined early and reliably. Because of this, good arc processing is possible. Furthermore, damage to the torch can be prevented.

It is a figure which shows the water circulation path of the arc processing apparatus concerning Embodiment 1 of this invention. It is a figure which shows the function previously stored in the flow volume setting circuit FR of FIG. It is a figure which shows the water circulation path of the arc processing apparatus concerning Embodiment 2 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the following description, a plasma welding apparatus in which a water circulation path is particularly likely to occur is taken as an example. This is because, in plasma welding, the torch is heated to a high temperature because the arc is confined by the plasma nozzle to achieve high density energy. Furthermore, the water circulation path of the plasma welding apparatus is a complicated water channel to enhance the cooling effect.

First Embodiment
FIG. 1 is a view showing a water circulation path of an arc processing apparatus according to a first embodiment of the present invention. As described above, this figure shows the case where the arc processing apparatus is a plasma welding apparatus. Each component will be described below with reference to the figure.

  The welding power source PS is a power source having a constant current characteristic or a drooping characteristic, one output terminal is connected to the electrode 1, the other output terminal is connected to the base material 2, and the welding current Iw and welding A voltage Vw is output to generate a plasma arc 3 between the electrode 1 and the base material 2.

  The torch WT surrounded by a broken line comprises an electrode 1, a plasma nozzle 4 surrounding it, and a shield nozzle 5 surrounding it. The electrode 1 is a non-consumable electrode, and a tungsten electrode is often used. A plasma gas (not shown) flows in the plasma nozzle 4. Further, a shield gas (not shown) flows in the shield nozzle 5. Argon gas is often used for plasma gas and shield gas. The plasma arc 3 is restrained by the plasma nozzle 4 and squeezed, and is generated between the electrode 1 and the base material 2. The plasma nozzle 4 is made of copper, and a flow passage through which water flows is provided inside for cooling.

  Although not shown, the water circulator WC includes a water tank, a pump, a blower and an internal water channel. The water 6 in the water tank is pumped out through the internal water channel to the outgoing path 7. The high temperature water 6 flowing in from the return path 8 is cooled by the blower and returns to the water tank through the internal water channel.

  An outward path 7 is a water channel connecting the water circulator WC and the torch WT, and a hose is used. A water pressure regulator PD is provided in the outward path 7. The water pressure regulator PD manually regulates the water pressure of the water 6 flowing through the outward route 7. The water pressure controller PD outputs a water pressure signal Pd of the adjusted water pressure value.

  The water 6 flowing into the torch WT from the forward path 7 flows through the internal water channel and the plasma nozzle 4 and flows out into the return path 8. Thus, the torch body of the torch WT, the plasma nozzle 4 and the like are cooled.

  The return path 8 is a water channel connecting the torch WT and the water circulator WC, and a hose is used. The return path 8 is provided with a flow rate detector FD. The flow rate detector FD detects the flow rate of the water 6 flowing through the return path 8 and outputs a flow rate signal Fd.

  The flow rate setting circuit FR calculates and outputs a flow rate setting signal Fr according to a predetermined function having the water pressure signal Pd as an input. This function is described in detail in FIG.

  The alarm determination circuit AR outputs an alarm signal Ar that is at a high level when the difference (absolute value) between the flow rate signal Fd and the flow rate setting signal Fr is equal to or greater than a predetermined first reference value.

  The alarm PL receives the above-mentioned alarm signal Ar and issues an alarm when the alarm signal Ar is at the high level. The alarm PL is, for example, a display, a buzzer or the like.

  As described above, the water circulation passage is formed of the inner water passage of the water circulator WC, the forward passage 7, the inner water passage of the torch WT, and the return passage 8. Water 6 whose pressure is adjusted by the water pressure regulator PD is circulated through the water circulation path.

  FIG. 2 is a view showing functions stored in advance in the flow rate setting circuit FR of FIG. The horizontal axis of the figure shows a water pressure signal Pd (MPa), and the vertical axis shows a flow rate setting signal Fr (l / min). This will be described below with reference to the same figure.

  Once the type of torch WT to be used is determined, the water channel structure is determined, and the appropriate range of water pressure is determined. When the water pressure is set within the appropriate range by the water pressure regulator PD, the flow rate in the corresponding normal state is determined. This figure shows the relationship between the water pressure signal pd and the corresponding flow rate setting signal Fr for two types of torches WT.

  Graph A is the case where the type of torch WT is type A. The appropriate range of the water pressure signal Pd in this case is 0.3 to 0.4 Mpa, and the corresponding flow rate setting signal Fr is 3 to 5 L / min. That is, in the case of type A, when Pd = 0.35, Fr = 4.

  The graph B is for the type of torch WT. The appropriate range of the water pressure signal Pd in this case is 0.45 to 0.55 Mpa, and the corresponding flow rate setting signal Fr is 2 to 3 L / min. That is, in the case of type B, when Pd = 0.5, Fr = 2.5.

  The water pressure signal Pd hardly changes even in the event of a failure such as water clogging or perforation in the water circulation path. Therefore, the flow rate setting signal Fr corresponding to the value of the water pressure signal Pd can be calculated, and when the value of the flow rate signal Fd is in the vicinity of the value of the flow rate setting signal Fr, it can be determined that the water circuit is in a normal state. . On the other hand, when the value of the flow rate signal Fd is separated from the value of the flow rate setting signal Fr by the first reference value abnormality, it can be determined that a fault has occurred in the water circuit.

Below, the effect of Embodiment 1 is demonstrated.
(1) When the welding current required for welding is determined from the thickness of the workpiece, etc., the type of torch WT to be used is determined.
(2) The water pressure is adjusted to an appropriate range by the water pressure regulator PD according to the type of torch WT.
(3) The water pressure signal Pd from the water pressure regulator PD is input to the flow rate setting circuit FR.
(4) The flow rate setting circuit FR calculates the flow rate setting signal Fr from the type of the torch WT and the water pressure signal Pd.
(5) The alarm determination circuit AR receives the flow rate signal Fd from the flow rate detector FD and the flow rate setting signal Fr, and generates an alarm when the difference (absolute value) between the two values is larger than a predetermined first reference value. The signal Ar is set to high level and output.
(6) When the alarm signal Ar is at the high level, the annunciator PL performs notification by light, sound or the like.
(7) When the worker confirms the notification, he or she can recognize that a failure has occurred in the water circulation path. Therefore, the worker can remove the cause of the failure and return the level circuit to a normal state.

  According to the first embodiment, even when there are a plurality of types of torches, the normal flow rate threshold can be set in accordance with the type of torch to be used. It can be determined accurately. Furthermore, even if the adjustment value of the water pressure changes, the normal flow threshold can be set according to the adjusted water pressure, so early and accurate determination of the occurrence of the water circulation path failure can be made. it can. Therefore, the occurrence of welding defects can be suppressed. In addition, damage to the torch can be prevented.

Second Embodiment
FIG. 3 is a view showing a water circulation path of an arc processing apparatus according to a second embodiment of the present invention. This figure corresponds to FIG. 1, and the same reference numerals are given to the same components and their description will not be repeated. This figure is obtained by adding the solenoid valve DB, the shutoff determination circuit SD and the solenoid valve control circuit BC to FIG. Hereinafter, these components will be described with reference to the figure.

  The solenoid valve DB is provided in the forward path 7 and opens and closes the flow of water supply.

  The shutoff determination circuit SD is at High level when the difference (absolute value) between the flow rate signal Fd and the flow rate setting signal Fr is equal to or greater than a second reference value predetermined to be larger than the first reference value. The shutoff signal Sd is output.

  The solenoid valve control circuit BC receives the above-described shutoff signal Sd and, when the shutoff signal Sd is at the high level, brings the solenoid valve DB into the shutoff state.

  According to the second embodiment described above, when the difference (absolute value) between the flow rate signal Fd and the flow rate setting signal Fr is a second reference value abnormality of a value larger than the first reference value at which the alarm signal Ar is output. The system shuts off the water supply with the solenoid valve DB provided in the forward path 7 in the shutoff state. The case where the second reference value is exceeded is the case where the water circulation passage, particularly the water passage of the torch WT, is perforated and a water leak occurs. Or it is a case where parts, such as a plasma nozzle, were removed for exchange etc. In such a case, water leakage can be prevented by blocking water supply. If a water leak is left, welding defects will occur, and the torch WT will be burned out.

  In the first and second embodiments, the arc machining device is a plasma welding device, but the same applies to an arc welding device and a plasma cutting device.

1 electrode 2 base material 3 plasma arc 4 plasma nozzle 5 shield nozzle 6 water 7 forward path 8 return path AR alarm determination circuit Ar alarm signal BC solenoid valve control circuit DB solenoid valve control valve FD flow detector Fd flow signal FR flow setting circuit Fr flow setting signal Iw welding current PD water pressure regulator Pd water pressure signal PL alarm PS welding power source SD shutoff determination circuit Sd shutoff signal Vw welding voltage WC water circulation machine WT torch

Claims (3)

A water circulation path of an arc processing apparatus formed of an internal water channel of a water circulator, an outward path, an internal water channel of a torch, and a return path,
A water pressure control unit that adjusts the water pressure in the forward path and outputs a water pressure signal;
A flow rate detection unit that detects a flow rate of the return path and outputs a flow rate signal;
A flow rate setting unit that calculates a flow rate setting signal according to a predetermined function using the water pressure signal as an input;
An alarm determination unit that outputs an alarm signal when the difference between the flow rate signal and the flow rate setting signal is equal to or greater than a predetermined first reference value;
A notification unit that notifies the alarm signal as an input;
A water circulation path of an arc processing apparatus characterized by comprising: A solenoid valve for opening and closing the forward path;
A shutoff determination unit which outputs a shutoff signal when the difference between the flow rate signal and the flow rate setting signal is equal to or greater than a second reference value predetermined to a value larger than the first reference value;
A solenoid valve control unit which receives the shutoff signal as an input and brings the solenoid valve into a shutoff state;
The water circulation path of the arc processing apparatus according to claim 1, further comprising: Change the function according to the type of the torch,
The water circulation path of the arc processing apparatus of Claim 1 or Claim 2 characterized by the above-mentioned.

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