JP5406056B2 - Torch height holding device in base material processing equipment - Google Patents

Description

The present invention relates to an apparatus for measuring the wear amount of an electrode of a torch, an apparatus for measuring the life of an electrode of the torch, and the height of the torch in a matrix processing apparatus for processing the matrix such as cutting or welding of the matrix. The present invention relates to a device that keeps constant.

Arc cutting and arc welding are widely used in the fields of cutting and welding. In this kind of base material processing apparatus, an electrode is provided on the torch, and an arc having an arc length corresponding to the arc voltage applied between the electrode and the base material is generated, and the torch is moved along the processing line of the base material. To move the base material. Below, it demonstrates taking a cutting device as an example.

The cutting device is usually provided with an AVC (arc voltage control) device.

The AVC apparatus compares the measured arc voltage with the set reference arc voltage and moves the cutting torch in the height direction of the base material so as to keep the arc length constant, thereby cutting the cutting torch and the base metal. It is a device that performs control to adjust the distance to the material. This control is intended to always keep the arc length constant even if the cutting torch is inclined or the position of the base material surface in the height direction changes due to thermal distortion of the base material. The arc length is determined according to the thickness of the base material R, and the reference arc voltage is determined accordingly. This is because the arc length and the reference arc voltage for making the cutting width a specified width differ according to the thickness of the base material R. For this purpose, a reference arc voltage necessary for setting the cutting width to a specified width is set corresponding to the plate thickness.

FIG. 1 shows the positional relationship between the cutting torch 10 and the base material R in time series.

When the cutting torch 10 is positioned at the cutting start position, an operation for measuring the height of the cutting torch 10 (IHS operation) is performed, and the piercing process is started. In the piercing process, the position of the cutting torch 10 in the height direction is adjusted to a certain height direction position Hp suitable for piercing. Then, a pierce hole is opened at the cutting start position by jetting plasma from the cutting torch 10. Thereafter, the cutting torch 10 moves along the weld line and accelerates to a constant speed (acceleration process). In the acceleration step, the position of the cutting torch 10 in the height direction is maintained at a constant height direction position Hs. When the cutting torch 10 reaches a constant speed, control by the AVC device is started from the AVC start point. Thereafter, the height direction position of the cutting torch 10 varies as the surface height direction position of the base material R varies.

The acceleration process from the start of the cutting to the AVC start point after the cutting torch 10 starts moving from the cutting start position is time-controlled. When the predetermined time has elapsed since the cutting torch 10 started moving from the cutting start position, control by the AVC device is started.

Here, if the electrode 11 is not worn, the arc length is proportional to the distance ΔL between the cutting torch 10 and the base material R and the distance ΔL between the cutting torch 10 and the base material R during the control by the AVC apparatus. Should be held constant.

However, when the electrode 11 is worn, the arc length is increased by the amount of wear and the arc voltage is increased. Therefore, in order to keep the arc length constant, the cutting torch 10 is lowered so that the arc voltage is adjusted to the reference arc voltage.

However, when the cutting torch 10 is lowered to the limit value, as shown in FIG. 2A, the cross-sectional shape of the cutting groove is tapered (shown by a solid line) compared to the original shape (shown by a broken line). As a result, the quality of the product deteriorates. Further, when the cutting torch 10 is lowered to the limit value, dross adhesion to the base material R becomes prominent, which may adversely affect the product quality, or the double arc may cause damage to the nozzle of the cutting torch 10. As shown in FIG. 2 (b), when the damage of the nozzle 12 proceeds, the dimension of the cutting width becomes wider (indicated by the broken line) than the original dimension (indicated by the broken line), and the product dimensions are reduced. An error may occur. Thus, the reduction in the height position of the cutting torch 10 greatly affects the reduction in the life of the cutting torch 10 and the deterioration of product quality.

Therefore, it is necessary to avoid that the cutting torch 10 is lowered to the limit value as the wear of the electrode 11 progresses.

(Conventional technology for life management of cutting torch)
Generally, the life management of the cutting torch including the electrodes is left to the operator. That is, for example, the cutting torch is replaced with a new one at a necessary time based on a table in which the replacement time is specified in accordance with the type of cutting torch.

Further, as described with reference to FIG. 2B, when the damage of the nozzle 10a progresses, the size of the cutting width becomes wide. Therefore, the wear size of the cutting torch including the nozzle is estimated by measuring the product size. A technique is also being implemented.

There is also a device that measures the cutting time and the number of piercings and outputs an alarm signal when the measured value reaches a specified value to prompt the replacement of the cutting torch.

(Prior art related to the life management of cutting torch)
Patent Document 1 described below is an invention in which the center position of the tip of the electrode in the cutting torch is measured, and it is determined whether the electrode has reached the replacement time by comparing the measured value with the value measured in the same way when new. Is described.

  In Patent Document 2 below, the amount of consumption of the electrode in the cutting torch is calculated based on the amount of electric power consumed by the arc and the number of times the arc is started, and when the calculated amount of electrode consumption exceeds the limit consumption amount An invention is described in which it is determined that the electrode has reached the replacement time.

  Patent Document 3 described below describes an invention in which electrode consumption is detected by monitoring a voltage between a nozzle member and a nozzle protective cover.

JP-A-6-226252 JP-A-5-277744 JP 2006-7315 A

  All of the prior arts related to the life management of the cutting torch are affected by the cutting conditions such as the plasma power source and the thickness of the base metal, and the measurement errors of the wear amount and the life time are large. Moreover, what was described in patent document 3 can be applied only to a special cutting torch equipped with a nozzle protection cover.

  Furthermore, in the prior art, the influence of control by the AVC apparatus is not taken into consideration at all. That is, if the control by the AVC apparatus is executed while the wear of the electrode is progressing, the height position of the cutting torch is lowered, resulting in deterioration of product quality and the like.

The present invention has been made in view of such circumstances, and a first problem to be solved is to accurately measure the amount of wear of the electrode of the torch and accurately determine the replacement time of the torch. It is.

Moreover, even if the wear of the electrode progresses, the second problem to be solved is to prevent the height of the torch from being lowered and to prevent the life of the torch and the product quality from being deteriorated.

The first invention is
An electrode is provided on the torch, and the base material is processed by moving the torch along the processing line of the base material while generating an arc having an arc length corresponding to the arc voltage applied between the electrode and the base material. In the base material processing equipment,
Arc voltage measuring means for measuring the arc voltage;
Distance measuring means for measuring the distance between the torch and the base material;
Control means that starts control after a predetermined time from the start of machining, and compares the measured arc voltage with a set reference arc voltage to keep the arc length constant so that the height of the base metal Arc voltage control means for performing control to adjust the distance between the torch and the base material by moving in the direction;
Within the predetermined time from the start of processing, the arc voltage is measured by the arc voltage measuring means, the distance between the torch and the base material is measured by the distance measuring means, and the measured arc voltage and the distance between the torch and the base material are measured. The electrode wear amount measuring device in the base material processing apparatus is provided with electrode wear amount calculating means for calculating the electrode wear amount based on the above.

The second invention is the first invention,
The base material further comprising alarm signal generation means for generating an alarm signal when the electrode wear amount reaches the threshold value by comparing the electrode wear amount calculated by the electrode wear amount calculation means with the threshold value. It is an electrode lifetime measuring apparatus in a processing apparatus.

The third invention is the first invention or the second invention,
According to the electrode wear amount calculated by the electrode wear amount calculation means, the measured arc voltage is corrected so as to keep the distance between the torch and the base material constant, and this corrected arc voltage is supplied to the arc voltage control means. An arc voltage correcting means for outputting is further provided,
The arc voltage control means
Control that adjusts the distance between the torch and the base metal by moving the torch in the height direction of the base metal so that the corrected arc voltage is compared with the set reference arc voltage and the arc length is kept constant. It is a torch height holding device in the base material processing apparatus.

4th invention is 1st invention or 2nd invention,
According to the electrode wear amount calculated by the electrode wear amount calculation means, the reference arc voltage is corrected so as to keep the distance between the torch and the base material constant, and this corrected reference arc voltage is output to the arc voltage control means. A reference arc voltage correcting means for further comprising:
The arc voltage control means
Replace the set reference arc voltage with the corrected reference arc voltage, and move the torch in the height direction of the base metal so that the measured arc voltage is compared with the corrected reference arc voltage and the arc length is kept constant. And a torch height holding device in a base material processing apparatus that performs control to adjust the distance between the torch and the base material.

A fifth invention is the first invention,
An electrode wear amount management means for managing the wear amount of the electrode of the torch is provided for each torch management number or for each thickness of the base material.

  According to the present invention, the following effects can be obtained.

a) The amount of wear of the torch electrode can be known accurately, and the replacement time of the torch can be accurately determined (first invention). Furthermore, it becomes possible to know the exact time when the wear amount of the electrode of the torch reaches the limit by the alarm (second invention).

b) Even if wear of the electrode of the torch progresses, it can be avoided that the height position of the torch is lowered, and the life of the torch and the product quality can be prevented from being deteriorated (third invention, third invention). 4 invention).

c) The amount of electrode wear can be controlled for each type of torch or for each plate thickness of the base material, and even when multiple torches are used in combination, the replacement time of each torch can be set without error. An accurate determination can be made (fifth invention).

FIG. 1 is a diagram showing the positional relationship between a cutting torch and a base material in time series. FIGS. 2A and 2B are diagrams used for explaining the problems of the prior art and the present invention. FIG. 3 is a block diagram showing the configuration of the entire system of the embodiment. FIG. 4 is a diagram for explaining the principle of measuring the amount of electrode wear. FIG. 5 is a diagram showing a geometric relationship between the trajectory of the cutting torch from the arc voltage measurement start point to the arc voltage measurement end point and the inclination of the base material. FIG. 6 is a diagram illustrating a signal flow in the embodiment in which the height position of the cutting torch is held. FIG. 7 is a flowchart showing a processing procedure in an embodiment for managing a plurality of cutting torches.

Hereinafter, an electrode wear amount measuring device, an electrode life measuring device, and a torch height holding device in a base material processing apparatus according to the present invention will be described with reference to the drawings.

  In the embodiment, a cutting apparatus will be described as an example. However, the present invention can be similarly applied to a welding apparatus.

  The cutting apparatus will be described assuming a plasma cutting apparatus, for example.

FIG. 3 is a block diagram showing the configuration of the entire system of the embodiment.

As shown in FIG. 3, the system of the embodiment mainly includes a cutting torch 10, a plasma power supply device 20, an arithmetic processing device 30, a stroke sensor 31, a touch panel 32, an AVC device 40, an alarm. The generator 50 is comprised. FIG. 3 shows only the components according to the present invention, and the components in the actual system that are not directly related to the present invention are omitted.

The cutting torch 10 includes an electrode 11 provided in the cutting torch 10 and a nozzle 12 provided at the tip of the cutting torch 10. A base material cutting apparatus that performs a cutting process using a plasma arc generates a plasma arc having an arc length corresponding to an arc voltage Va applied between the electrode 11 and the base material R and generates plasma from the nozzle 12 with the base material R. The cutting torch 10 is moved along the processing line of the base material R while being jetted toward the base material, thereby cutting the base material R.

The plasma power supply device 20 applies an arc voltage Va between the electrode 11 (negative electrode) and the base material R (positive electrode) of the cutting torch 10. The arc voltage Va is measured by an arc voltage measuring means 21 provided in the plasma power supply device 20. The arc voltage Va measured by the arc voltage measuring means 21 is input to the arithmetic processing unit 30.

The stroke sensor 31 detects a position (hereinafter simply referred to as “height”) H in the height direction of the cutting torch 10. A signal indicating the height H of the cutting torch 10 detected by the stroke sensor 31 is input to the arithmetic processing unit 30.

The touch panel 32 includes an input unit 33 and a display unit 34. A signal indicating the content input by the input unit 33 is input to the arithmetic processing device 30. On the display unit 34, display is performed according to the display signal output from the arithmetic processing device 30.

The alarm generation device 50 generates an alarm according to the alarm signal output from the arithmetic processing device 30. The alarm generation device 50 is configured by, for example, a buzzer or Patlite (registered trademark) .

The AVC device 40 sets the cutting torch 10 of the base material R so as to maintain a constant arc length by comparing a corrected arc voltage Va1 (described later) input from the arithmetic processing device 30 with a set reference arc voltage. Control is performed to adjust the distance between the cutting torch 10 and the base material R by moving in the height direction. This control is to keep the arc length constant even when the cutting torch 10 is inclined or the position of the base material surface in the height direction changes due to thermal distortion of the base material R or the like. . The arc length is determined according to the thickness of the base material R, and the reference arc voltage is determined accordingly. This is because the arc length and the reference arc voltage for making the cutting width a specified width differ according to the thickness of the base material R. For this purpose, a reference arc voltage necessary for setting the cutting width to a specified width is set corresponding to the plate thickness.

  Each example will be described below.

(First embodiment: measurement of electrode wear)
FIG. 4 is a diagram for explaining the principle of measuring the wear amount of the electrode 11.

When the wear amount of the electrode 11 is ΔD, the length of the nozzle 12 is ΔN, and the distance between the cutting torch 10 and the base material R is ΔL, the arc voltage Va and
Va = K1 · ΔL + K2 · ΔD + K3 · ΔN (1)
The relationship is established. However, K1, K2, and K3 are known constants. The nozzle length ΔN is a known value. The distance ΔL between the cutting torch 10 and the base material R is obtained from the height H of the cutting torch 10 detected by the stroke sensor 31 and the plate thickness (known) of the base material R. Instead of the stroke sensor 31, it is possible to provide a distance measuring means for directly measuring the distance ΔL between the cutting torch 10 and the base material R.

When the above equation (1) is transformed, the electrode wear amount ΔD is
ΔD = (Va−K1 · ΔL−K3 · ΔN) / K2 (2)
Therefore, the arc voltage Va is measured by the arc voltage measuring means 21 and the distance ΔL between the cutting torch 10 and the base material R is measured based on the torch height H detected by the stroke sensor 31 (or The distance ΔL is directly measured by the distance measuring means), and the wear amount ΔD of the electrode 11 can be calculated based on the measured arc voltage Va and the distance ΔL between the cutting torch 10 and the base material R.

  However, while the control by the AVC device 40 is being executed, the position in the height direction of the cutting torch 10 fluctuates, and an accurate arc voltage Va cannot be measured. Therefore, the arc voltage Va is measured by the arc voltage measuring means 21 during a period when the control by the AVC device 40 is not executed.

FIG. 1 shows the positional relationship between the cutting torch 10 and the base material R in time series.

When the cutting torch 10 is positioned at the cutting start position, the cutting torch 10 is lowered until it comes into contact with the base material R, and is raised from this position to a height Hp corresponding to the thickness of the base material R ( IHS operation). The height Hp is a height suitable for piercing. The height Hp is measured by the stroke sensor 31. Then, after a process of forming an arc, the process enters a piercing process. In the piercing process, the height H of the cutting torch 10 is maintained at a constant height Hp suitable for piercing. Then, plasma is jetted from the cutting torch 10 and a piercing hole is opened at the cutting start position.

Thereafter, the cutting torch 10 moves along the weld line and accelerates to a constant speed (acceleration process). In the acceleration step, the position of the cutting torch 10 in the height direction is maintained at a constant height direction position Hs. In this acceleration process, control by the AVC device 40 is not performed.

Therefore, in this acceleration step, the arc voltage Va is measured by the arc voltage measuring means 21 at a predetermined sampling period.

FIG. 5 shows the geometric relationship between the trajectory of the cutting torch 10 from the arc voltage measurement start point (acceleration start point) to the arc voltage measurement end point (acceleration end point) and the inclination of the base material R. Is. The inclination of the base material R is caused by the inclination of a surface plate (base) on which the base material R is placed, dross accumulated on the surface plate, or the like. If the base material R is inclined, an error occurs in the measured arc voltage Va. Therefore, it is necessary to correct by subtracting the error due to the inclination from the measured arc voltage Va.

In FIG. 5, ε is an arc voltage measurement error. Therefore, in order to eliminate this arc voltage measurement error, correction is performed by calculating the slope of the primary equation from the increasing / decreasing tendency of the measured arc voltage. Specifically, the following correction calculation is performed.

Va ′ = Σ (Vai−i · atan (VaN−Va1 / N) / N (3)
However, since Vai may be accompanied by lowering of the torch during acceleration, it is intended for the voltage range defined by the plasma power source and the plate thickness, and at the i-th (i = 1, 2,... N) sampling. VaN is the measured arc voltage, and VaN is the arc voltage measured during the last Nth sampling.

The arc voltage Va ′ corrected by the above equation (3) is substituted into the above equation (2) to obtain the electrode wear amount ΔD.

In this manner, the wear amount ΔD of the electrode 11 is calculated by the electrode wear amount calculation means 35 of the arithmetic processing unit 30.

Here, in general, the average voltage drop when the electrode 11 is worn to the limit value is about 8 V in terms of arc voltage. Usually, since the arc voltage is about 100V to 200V, the required measurement resolution is 4% or less. This is equivalent to 5 bits of A / D conversion accuracy. Further, considering noise superimposed on the waveform, 8 bits (256) or more are required. Further, the arithmetic processing unit 30 requires an A / D conversion function with the above-described accuracy and a low-pass filter for removing high-frequency noise (the fluctuation of the positive electrode point of the plasma is several kHz). An arc voltage sampling period of 1 ms is sufficient. Therefore, it is possible to cope with soft filter processing instead of a hard filter circuit. The arc voltage is processed by dropping it to 10 V or less via a voltage attenuator.

Each time the base material R is cut, the wear amount ΔD of the electrode 11 sequentially calculated by the electrode wear amount calculating means 35 is converted into a display signal and output to the display unit 34 of the touch panel 32. As a result, the current wear amount ΔD of the electrode 11 is displayed on the display unit 34 of the touch panel 32, and the operator can always check the wear state of the cutting torch 10.

(Second embodiment: combined use of electrode wear measurement and torch life measurement)
On the other hand, the threshold value setting unit 36 of the arithmetic processing unit 30 is set with a threshold value ΔDc for determining whether or not the wear amount ΔD of the electrode 11 has reached a limit value.

In the alarm signal generation means 136, the electrode wear amount ΔD calculated by the electrode wear amount calculation means 35 is compared with a threshold value ΔDc. As a result, when the electrode wear amount ΔD reaches the threshold value ΔDc, an alarm signal is generated and the alarm signal is output to the alarm generator 50. As a result, an alarm is generated by the alarm generator 50. Thereby, the operator can recognize that the wear of the electrode 11 has reached the limit, and can take measures such as replacing the cutting torch 10 with a new one. Note that the alarm content may be displayed on the display unit 34 by outputting an alarm signal to the touch panel 32.

Other methods may be used in combination to determine the life of the cutting torch 10.

Normally, when either the electrode 11 or the nozzle 12 reaches the end of its life, the electrode 11 and the nozzle 12 are replaced at the same time. The life of the cutting torch 10 is expressed as the sum of the wear of the electrode 11 and the nozzle 12. The wear of the electrode 11 and the nozzle 12 is defined by the arc time (cutting time) and the number of piercings. The arc time is defined by the type of power source of the plasma power source device 20, the type of gas, and the type (material) of the electrode 11. The cutting time is obtained by measuring the time during which the arc voltage is equal to or higher than the specified value. The number of times of piercing is accumulated from the arc voltage and the cutting torch 10 height.

In the life calculation unit 37 of the arithmetic processing unit 30, the life time of the cutting torch 10 is calculated by the following equation.

Life time = Cutting time + K · Number of piercings (4)
K is a time converted value of the degree of wear of the cutting torch 10 accelerated by the number of piercings. The value of K is stored in the database 38 as a known value corresponding to the type of power source of the plasma power supply device 20, the type of gas, and the type (material) of the electrode 11. For this reason, the arithmetic processing unit 30 requires a nonvolatile memory having an appropriate capacity.

In the alarm signal generation means 136, the lifetime calculated by the lifetime calculator 37 is compared with a specified value. As a result, when the lifetime exceeds the specified value, an alarm signal is generated and the alarm signal is output to the alarm generator 50. As a result, an alarm is generated by the alarm generator 50. Thereby, the operator can recognize that the wear of the electrode 11 or the nozzle 12 has reached the limit, and can take measures such as replacing the cutting torch 10 with a new one.

It is desirable that the alarm signal generated when the lifetime exceeds the specified value can be distinguished from the alarm signal generated when the electrode wear amount ΔD reaches the threshold value ΔDc. Also in this case, each alarm signal may be output to the touch panel 32 and the alarm content may be displayed on the display unit 34.

(Third embodiment: Torch height maintenance)
If the electrode 11 is not worn, the arc length is proportional to the distance between the cutting torch 10 and the base material R during the control by the AVC device 40, and the distance ΔL between the cutting torch 10 and the base material R is Should be held constant.

However, when the electrode 11 is worn, the arc length is increased by the wear amount, and the measured arc voltage Va is increased. Therefore, in order to keep the arc length constant, the cutting torch 10 is lowered and adjusted so that the arc voltage is lowered to the reference arc voltage.

However, when the cutting torch 10 is lowered to the limit value, as described with reference to FIG. 2A, the life of the cutting torch 10 and the product quality are greatly affected. For this reason, it is necessary to avoid that the cutting torch 10 falls to the limit value as the wear of the electrode 11 progresses.

Therefore, in the present embodiment, the arc voltage correction means 39 is provided in the arithmetic processing unit 30, and the arc voltage Va 1 corrected by the arc voltage correction means 39 is output to the AVC device 40, so that the height of the cutting torch 10 is increased. To keep.

FIG. 6 is a diagram illustrating a signal flow in the present embodiment. Hereinafter, description will be made with reference to this figure.

The arc voltage measuring means 21 provided in the plasma power supply device 20 measures the actual arc voltage Va. The arc voltage Va measured by the arc voltage measuring unit 21 is input to the arc voltage correcting unit 39 of the arithmetic processing unit 30.

The arc voltage correction means 39 measures the measured arc voltage Va so as to keep the distance between the cutting torch 10 and the base material R constant according to the electrode wear amount ΔD calculated by the electrode wear amount calculation means 35. Is corrected and calculated as shown below to generate a corrected arc voltage Va1.

Va1 = Va−K2 · ΔD (5)
The corrected arc voltage Va1 is output to the AVC device 40.

In the AVC device 40, the measured arc voltage Va is replaced with the corrected arc voltage Va1, and control is performed. In other words, the cutting torch 10 is moved in the height direction of the base material R so that the corrected arc voltage Va1 is compared with the set reference arc voltage and the arc length is kept constant, so that the cutting torch 10 and the base Control to adjust the distance to the material R is performed.

Thereby, even if the wear of the electrode 11 proceeds, the cutting torch 10 is held at a constant height without lowering. In addition, according to the present embodiment, it is not necessary to manually change the reference arc voltage, and the control for automatically maintaining the height of the cutting torch 10 constant is realized. Furthermore, according to the present embodiment, the arc voltage correction means 39 (the arithmetic processing unit 30) is added between these devices without any modification or processing of the existing plasma power supply device 20 and AVC device 40. With a simple system configuration, a remarkable effect is obtained that the height of the cutting torch 10 can be automatically maintained constant.

In this embodiment, the measured arc voltage Va is corrected and the control by the AVC device 40 is performed. However, the control by the AVC device 40 may be performed by correcting the reference arc voltage.

In this case, the reference currently set by the AVC device 40 so as to keep the distance between the cutting torch 10 and the base material R constant according to the electrode wear amount ΔD calculated by the electrode wear amount calculating means 35. The arc voltage Vth is corrected and calculated as shown below to generate a corrected reference arc voltage Vth1.

Vth1 = Vth + K2 · ΔD (6)
The corrected reference arc voltage Vth1 is output to the AVC device 40.

The AVC device 40 performs control by replacing the currently set reference arc voltage Vth with the corrected reference arc voltage Vth1. That is, the cutting torch 10 is moved in the height direction of the base material R so that the arc voltage Va measured by the arc voltage measuring means 21 is compared with the corrected reference arc voltage Vth1 and the arc length is kept constant. Thus, control for adjusting the distance between the cutting torch 10 and the base material R is performed.

Thereby, even if the wear of the electrode 11 proceeds, the cutting torch 10 is held at a constant height without lowering.

(4th Example: Electrode wear amount management)
The arc voltage is a voltage difference from the anode point of the plasma in the base material R using the electrode 11 as a cathode. If the thickness of the base material R changes, the arc voltage Va measured during the acceleration process changes. This is because an appropriate torch height H (torch-base material distance ΔL) is determined in order to compensate the cutting performance in accordance with the thickness of the base material R.

Each time the base material R having a different plate thickness is cut, the cutting torch 10 is replaced with a type corresponding to the size of the plate thickness. In the acceleration step, the height Hs of the cutting torch 10 is adjusted to a height corresponding to the thickness of the base material R. Thus, when a plurality of different types of cutting torches 10 are used together, it is necessary to manage the amount of electrode wear for each type of cutting torch 10.

Therefore, the management means 131 of the arithmetic processing unit 30 manages the amount of wear of the electrode 11 of the cutting torch 10 for each thickness of the base material R.

Hereinafter, the procedure of processing performed by the arithmetic processing device 30 will be described with reference to the flowchart of FIG.

At the start of the cutting process, data on the type of power source, the type of gas, and the type (material) of the electrode 11 is input from the input unit 33 of the touch panel 32. As a result, the value K corresponding to the input data is read from the database 38. If the cutting torch 10 is new, data indicating "new" is input (step 101).

Next, the cutting torch 10 is set (step 102), and management number data indicating the type of the cutting torch 10 is input from the input unit 33 of the touch panel 32. The management number indicating the type of the cutting torch 10 corresponds to the thickness of the base material R (step 103).

Next, a cutting process is performed. During the cutting process, the cutting time, the number of piercings, the life time, and the electrode wear amount ΔD are calculated as described above.

The management means 131 stores and manages the history of the cutting time, the number of times of piercing, the life time, and the electrode wear amount ΔD in a memory corresponding to the management number indicating the type of the cutting torch 10.

If the cutting torch 10 is “new”, the history information of the cutting torch 10 with the corresponding management number is deleted, that is, the cutting time, the number of times of piercing, the lifetime, and the electrode wear amount ΔD are reset. The cutting time, the number of piercings, the life time, and the electrode wear amount ΔD of the management number cutting torch 10 are recorded in the memory.

On the other hand, when there is no input of “new” and the cutting torch 10 is an old product, the history information of the cutting torch 10 with the corresponding management number is taken over, that is, the cutting torch with the corresponding management number. The cutting time, the number of piercings, the life time, and the electrode wear amount of 10 are read from the memory, and the data is updated and stored in the memory by the newly calculated cutting time, the number of piercings, the life time, and the electrode wear amount ΔD (step 104) ).

As described above, the electrode wear amount ΔD, the cutting time, the number of times of piercing, and the lifetime are recorded in the memory for each management number. The recorded content is converted into a display signal and output to the display unit 34 of the touch panel 32. As a result, the display 34 of the touch panel 32 can display the electrode wear amount ΔD, the cutting time, the number of times of piercing, and the life time for each type (control number) of the cutting torch 10. The worn state of the torch 10 can be confirmed. In addition, an alarm signal is output based on the recorded content, and the alarm generation device 50 indicates that the electrode wear amount ΔD has reached the limit for each type (control number) of the cutting torch 10 or the lifetime has reached the limit. The operator can be informed of this.

In this embodiment, a management number indicating the type of cutting torch 10 is input, the type of cutting torch 10 is determined based on the input management number, and the amount of electrode wear and the like is managed for each type of cutting torch 10. However, it is possible to manage the amount of electrode wear and the like for each thickness of the base material R.

That is, during the acceleration process of the cutting torch 10, the thickness of the base material R is determined according to the height H of the cutting torch 10 detected by the stroke sensor 31, and the thickness of the base material R is determined. You may manage the abrasion amount etc. of the electrode 11 of the cutting torch 10 for every magnitude | size.

According to the embodiment described above, the following effects can be obtained.

a) The wear amount ΔD of the electrode 11 of the cutting torch 10 can be known accurately, and the replacement time of the cutting torch 10 can be accurately determined (first embodiment). Further, it becomes possible to know the exact time when the wear amount of the electrode 11 of the cutting torch 10 has reached the limit by a warning (second embodiment).

b) Using both the measurement of the electrode wear amount ΔD and the measurement of the lifetime of the cutting torch 10, an alarm can be generated when the limit is reached, and the replacement time of the cutting torch 10 can be accurately and accurately determined. It becomes possible to judge (second embodiment).

c) Even if the wear of the electrode 11 of the cutting torch 10 progresses, it can be avoided that the height position of the cutting torch 10 is lowered, and the life of the cutting torch 10 and the product quality are prevented from being deteriorated. (Third embodiment).

d) The amount of electrode wear ΔD, cutting time, number of times of piercing, and life time can be managed for each type of cutting torch 10 or each thickness of the base material R, and a plurality of cutting torches 10 are used in combination. Even in such a case, the replacement time of each cutting torch 10 can be accurately determined without error (fourth embodiment).

10 cutting torch, 30 arithmetic processing unit, 40 AVC unit, 50 alarm generator

Claims (2)

An electrode is provided on the torch, and the base material is processed by moving the torch along the processing line of the base material while generating an arc having an arc length corresponding to the arc voltage applied between the electrode and the base material. In the base material processing equipment,
Arc voltage measuring means for measuring the arc voltage;
Distance measuring means for measuring the distance between the torch and the base material;
Control means for starting arc voltage control after a predetermined time from the start of machining, comparing the input arc voltage with a set reference arc voltage, and setting the arc length during the arc voltage control after the predetermined time. Arc voltage control means for performing control to adjust the distance between the torch and the base material by moving the torch in the height direction of the base material so as to keep it constant;
The arc voltage is measured a plurality of times at a predetermined sampling period by the arc voltage measuring means within the predetermined time from the start of machining within the acceleration period in which the torch is accelerated until the torch reaches a constant speed without changing the height direction of the torch. The electrode wear amount is calculated by measuring the distance between the torch and the base material by the distance measuring means, and calculating the electrode wear amount based on the arc voltage and the distance between the torch and the base material measured a plurality of times. And a calculation means,
According to the electrode wear amount calculated by the electrode wear amount calculation means, a correction arc voltage for keeping the distance between the torch and the base material constant irrespective of the magnitude of the electrode wear amount, the arc voltage measurement means Arc voltage correction means for calculating based on the arc voltage measured by and outputting the calculated corrected arc voltage to the arc voltage control means,
The arc voltage control means is
The corrected arc voltage inputted is compared with a set reference arc voltage, and the torch is moved in the height direction of the base material so as to keep the arc length constant during the arc voltage control after the predetermined time. It is controlled to move and adjust the distance between the torch and the base material,
An alarm signal generating means for generating an alarm signal when the electrode wear amount reaches the threshold value by comparing the electrode wear amount calculated by the electrode wear amount calculating means with a threshold value is further provided. A torch height holding device in a base material processing apparatus characterized by the above. 2. The base material processing according to claim 1, further comprising electrode wear amount management means for managing the amount of wear of the electrode of the torch for each management number of the torch or for each thickness of the base material. Torch height holding device in the device.

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