JPH09103878A - Shaft copying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft copying device which prevents collision between an electrode and a work and which improves the finish of the work. SOLUTION: The shaft copying device 1 for machining a work W is provided with a voltage detecting device 21 for detecting an arc voltage outputted from an electrode 13 to the work W and gap control device 25 which controls the gap, with the voltage signal inputted that is detected by this voltage detecting device 21. The device 1 is further provided with a monitoring device 27 which monitors the amount of travel, its remaining amount or a travelling time of either the machining head 15 or the work W by a first driving means 9, and with a switching means 29 which, on the basis of these amounts monitored by the device 27, turns on/off the driving signal of a second driving means 19 from the gap control device 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls a gap between an electrode and a work to be processed by changing a voltage output from an electrode provided on a processing head in a plasma processing machine or a welding machine. The present invention relates to an axis copying processing device.

[0002]

2. Description of the Related Art Conventionally, in a plasma processing machine, a welding machine or the like as an axis copying processing apparatus, a change in arc voltage output from an electrode provided on a processing head is input to an axis control section of an NC apparatus, and this axis is controlled. The gap between the electrode and the work is controlled to be always constant by feeding back from the control unit to the axis that moves the machining head up and down.

For example, the conventional axis copying apparatus 101 is
As shown in FIG. 5, a work table 103 on which a work W to be machined is placed is provided, and above the work table 103, the X-axis movable in the left-right direction (X-axis direction) in FIG. A carriage 105 is provided. A ball screw 107 extending in the X-axis direction is screwed into the X-axis carriage 105.
An X-axis drive motor 109 such as a servo motor is connected to one end, for example, the right end of 07.

On the X-axis carriage 105, a Z-axis carriage 111 is provided which is movable in the vertical direction (Z-axis direction). A processing head 115 having an electrode 113 is mounted below the Z-axis carriage 111. A ball screw 117 extending in the Z-axis direction is screwed into the Z-axis carriage 111, and a Z-axis drive motor 119 such as a servo motor is connected to the upper end of the ball screw 117.

With the above configuration, the work W is placed on the work table 103, and the X-axis drive motor 109
The X-axis carriage 105 is moved in the X-axis direction by driving and rotating the ball screw 107.
Further, by driving the Z-axis drive motor 119 and rotating the ball screw 117, the Z-axis carriage 11
1 will be moved in the Z-axis direction.

A voltage detection device 121 is connected to the electrode 113 and the work W, and the voltage detection device 1 is also provided.
21 is connected to the NC device 123. Moreover, this N
The C device 123 is connected to the X-axis drive motor 109 and the Z-axis drive motor 119.

With the above construction, the X-axis carriage 105 can be moved in the X-axis direction and the Z-axis carriage 111 can be moved in the Z-axis direction, and at the same time, the arc output from the electrode 113 can be used to perform plasma processing or welding on the work W. Done.

At that time, a change in the arc voltage of the arc voltage output from the electrode 113 is detected by the voltage detecting device 121,
This detected voltage signal is taken in by the NC device 123, the motor drive signal is fed back from the NC device 123 to the Z-axis drive motor 119, and the electrode 113 and the workpiece W are fed.
Machining is performed by controlling the gap G between and so that it is always constant.

This control is important for finishing such as cutting the warped work W. Moreover, this control is based on the fact that the relationship between the gap G and the voltage is proportional, as shown in FIG.

[0010]

By the way, in the above-described conventional axis copying apparatus 101, the X-axis drive motor 1 is used.
When 09 is driven, the ball screw 107 is rotated and the X-axis carriage 105 is moved in the X-axis direction in FIG. 5, so that the electrode 113 is also moved in the same direction.

When the electrode 113 moves in the X-axis direction,
As shown in FIG. 7, the voltage also changes at the left and right speeds. This means that when the left and right speeds change, the gap G is considered to change and the electrode 113 is controlled in the vertical direction. That is, it is not known whether the voltage change is due to the gap G or the speed.

Since the left and right speeds are normally as shown in FIG. 8, the followability of the up and down control is good during acceleration and deceleration, so that the electrode 113 collides with the work W or the arc disappears. I will. Further, the finish of the work W is also deteriorated.

An object of the present invention is to provide an axial copying apparatus which prevents the electrode from colliding with the work and improves the finish of the work.

[0014]

In order to achieve the above-mentioned object, according to a first aspect of the present invention, there is provided an axial contour machining apparatus in which a machining head having an electrode and a workpiece to be machined are relatively first.
An axial copying machining apparatus for performing machining on a workpiece by moving the machining head in the vertical direction by a second driving means while moving the machining head by driving means and constantly controlling the gap between the electrode and the workpiece. A voltage detection device for detecting an arc voltage output from the electrode to the work, a gap control device for inputting a voltage signal detected by the voltage detection device to control the gap, and a machining head or a work by the first driving means. A monitoring device for monitoring one of the moving amount, the remaining moving amount, and the moving time, and the second driving means from the gap control device based on the moving amount, the remaining moving amount, or the moving time monitored by the monitoring device. Drive signal of
And a switching means for turning it off.

Therefore, when machining a workpiece,
In advance, input the movement amount during acceleration / deceleration for moving the work or electrode, the remaining movement amount, or the reference value of time to the monitoring device. Then, the actual movement amount or time of the work or electrode is input to the monitoring device, and the monitoring device compares the actual value with the reference value. If the actual value is not less than the reference value, the switch of the switching means is turned on. At least, a drive signal is applied from the gap control device to the second drive means to control the second drive means so that the gap between the electrode and the work is controlled to be constant.

If the actual value is less than or equal to the reference value, the switch of the switching means is turned off to prevent the gap control device from supplying the drive signal to the second drive means.
Since the driving means is controlled, it is possible to prevent the electrode from colliding with the work and improve the finish of the work.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, an axial copying apparatus 1 such as a plasma processing machine or a welding machine is a work W to be processed.
Is provided with a work table 3 on which the work table 3 is placed, and above the work table 3 in the left-right direction (X-axis direction) in FIG.
A movable X-axis carriage 5 is provided. The X-axis carriage 5 has a ball screw 7 extending in the X-axis direction.
An X-axis drive motor 9 such as a servo motor as a first drive means is connected to one end, for example, the right end of the ball screw 7. The X-axis drive motor 9 is provided with an encoder E ₁ for detecting the amount of movement.

With the above construction, when the X-axis drive motor 9 is driven, the ball screw 7 is rotated and the X-axis carriage 5 is moved in the X-axis direction.

On the X-axis carriage 5, the vertical direction (Z
A Z-axis carriage 11 that is movable in the axial direction) is provided. A processing head 15 having an electrode 13 is mounted below the Z-axis carriage 11. A ball screw 17 extending in the Z-axis direction is screwed into the Z-axis carriage 11, and a Z-axis drive motor 19 such as a servo motor as a second drive means is connected to the upper end of the ball screw 17. There is. The Z-axis drive motor 19 is equipped with an encoder E ₂ for detecting the amount of movement.

With the above structure, when the Z-axis drive motor 19 is driven, the ball screw 17 is rotated and the Z-axis carriage 11 is moved in the Z-axis direction.
The electrode 13 provided in the same is also moved in the same direction.

A voltage detecting device 21 is connected to the electrode 13 and the work W, and the voltage detecting device 21 is N
It is connected to the C device 23. Moreover, this NC device 23
Is connected to the X-axis drive motor 9 and the Z-axis drive motor 19.

With the above structure, the X-axis carriage 5 is moved in the X-axis direction and the Z-axis carriage 11 is moved in the Z-axis direction, and the workpiece W is processed by the arc output from the electrode 13 such as plasma processing or welding processing. Will be done.

The NC device 23 has an electrode 13 and a work W.
There is provided a gap control device 25 for controlling the gap G between the and, a monitoring device 27 for monitoring the movement amount and the remaining movement amount when the X-axis carriage 5 moves in the X-axis direction, and a switching means 29.

The gap control 25 takes in the voltage signal detected by the voltage detection device 21 and applies a normal up / down drive signal to the Z-axis drive motor 19 so that the gap G is always constant. The drive signal is added with the drive signal.

In the monitoring device 27, for example, as shown in FIG. 2, when the X-axis carriage 5 is moved from the start point to the end point (target), the current position A is set as L when the total distance is L. By always detecting, the moving amount L ₀ from the start point to the current position A and the remaining moving amount L _S (= L−L ₀ ) from the current position A to the end point are calculated and compared with the reference value L _K. It is a thing.

As shown in FIG. 3, the monitoring device 27 has a total distance / memory 31 for inputting and storing the total distance L in advance, and an encoder E provided in the X-axis drive motor 9. _The current position / memory 33 for inputting and storing the current position A detected in ₁ and the movement amount L ₀
Of the moving amount, a remaining moving amount calculating unit 37 for calculating the remaining moving amount L _S w, a reference value / memory 39 for inputting and storing the reference value L _K in advance, and a reference value L _K.
And a moving amount L ₀ and a remaining moving amount L _S.
1 and 1.

The operation of controlling the gap G between the electrode 13 and the work W with the above configuration will be described with reference to the flow chart shown in FIG. 4. The reference value stored in the memory 39 in step S1 is the reference value. The value L _K is input to the comparison calculation unit 41. Current position in step S2
The current position A stored in the memory 33 is the movement amount calculation unit 35.
The moving amount L ₀ is fetched by the _CPU and arithmetically processed, and the calculated moving amount L ₀ is input to the comparison and determination section 41.

In step S3, the moving amount L ₀ and the reference value L _K are compared and judged by the comparing and judging section 41, and if the moving amount L ₀ is not less than the reference value L _K (L ₀ <L _K ), the step Proceed to S4. In step S4, the total distance / memory 3
The total distance L stored in 1 and the movement amount L ₀ calculated by the movement amount calculation unit 35 are taken into the remaining movement amount calculation unit 37 and the remaining movement amount L ₃ (= L−L ₀ ) is calculated. It is processed and input to the comparison / determination unit 41.

In step S5, the comparison determination unit 41 compares and determines the remaining movement amount L _S and the reference value L _K, and the remaining movement amount L _S is not less than or equal to the reference value L _K (L _S ≤L _K ). ,
In step S6, the switch of the switching means 29 is turned on.

In step S3, the movement amount L ₀ is the reference value L _0.
If it is _K or less (L ₀ ≧ L _K ), and if the remaining movement amount is the reference value L _K or less in step S5 (L _S ≧ L _K ), the switch of the switching means 29 is turned off in step S7. .

When the switch of the switching means 29 is turned on,
Up and down drive signals are added to the normal up and down drive signals from the gap control device 25 to control the Z-axis drive motor 9 so that the gap G is constantly controlled under the relationship shown in FIG. Can be processed. When the switch of the switching means 29 is turned off, the upper and lower drive signals are not added to the normal upper and lower drive signals from the gap control device 25, and only the normal upper and lower drive signals are given to the Z-axis drive motor 9. The work W can be controlled and processed.

Then, the switch of the switching means 29 is turned off by the amount of acceleration / deceleration in the movement of the X-axis carriage 5 (when it is the reference value L _K or less), and the upper and lower drive signals from the gap control 25. When the X-axis drive motor 9 is controlled only by the normal upper and lower drive signals without being added to the normal upper and lower drive signals, the relationship shown in FIG. 6 does not hold, but can be ignored. At this time, the amount of acceleration / deceleration is usually several mm at a time, and the warp of the work W during this period is usually almost zero. Therefore, the finish of the work W is not affected and the finish of the work W can be improved. Moreover, it is possible to prevent collision between the electrode 13 and the work W, misfire of the arc, and the like.

The present invention is not limited to the above-described embodiment, but can be embodied in other modes by making appropriate changes. In the example of the present embodiment, an example in which the monitoring device 27 monitors the movement amount during acceleration / deceleration and the remaining movement amount and the ON / OFF is controlled by the switch of the switching means 29 has been described. Since the parameter of the time constant (inclination) is known in the NC device 23, the monitoring device 27 may monitor the time during acceleration / deceleration and the switch of the switching means 29 may control ON / OFF. is there.

In the example of the present embodiment, the work W is fixed and the X-axis carriage 5 is moved in the X-axis direction. However, the X-axis carriage 5 is fixed and the work W is moved to the X-axis.
It may be configured so that it can be moved in the axial direction. Further, the workpiece W or the machining head 15 is fixed, and the machining head 15 or the workpiece W is two-dimensionally (X, Y axis direction), 3
It may be arranged so that it can be moved in the dimensions (X, Y, Z axis directions).

The signal from the voltage detection device 21 may detect a current instead of a voltage, and may be either analog or digital.

[0037]

As can be understood from the above-described embodiments, the invention according to claim 1 accelerates or decelerates the work device or the electrode in advance by the monitoring device when the work is processed. Enter the time movement amount, remaining movement amount, or time reference value. Then, the actual movement amount or time of the work or electrode is input to the monitoring device, and the monitoring device compares the actual value with the reference value. If the actual value is not less than the reference value, the switch of the switching means is turned on. At least, a drive signal is applied from the gap control device to the second drive means to control the second drive means so that the gap between the electrode and the work is controlled to be constant.

If the actual value is less than or equal to the reference value, the switch of the switching means is turned off so that the drive signal is not applied from the gap control device to the second drive means.
Since the driving means is controlled, it is possible to prevent the electrode from colliding with the work and improve the finish of the work.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an axial copying apparatus embodying the present invention.

FIG. 2 is an explanatory diagram of a movement amount and a remaining movement amount monitored by a monitoring device.

FIG. 3 is a configuration block diagram of a monitoring device.

FIG. 4 is a flowchart for controlling a gap between an electrode and a work according to the present invention.

FIG. 5 is a configuration diagram of a conventional axial copying apparatus.

FIG. 6 is a diagram showing a relationship between a gap between an electrode and a work and a voltage.

FIG. 7 is a diagram showing a relationship between a gap between an electrode and a work and a voltage.

FIG. 8 is a diagram showing an example of a velocity diagram of a movement amount.

[Explanation of reference numerals] 1-axis copying processing device 5 X-axis carriage 9 X-axis drive motor (first drive means) 11 Z-axis carriage 15 Processing head 19 Z-axis drive motor (second drive means) 21 Voltage detection device 23 NC device 25 Gap control device 27 Monitoring device 29 Switching means

Claims (1)

[Claims] 1. A machining head provided with an electrode and a workpiece to be machined are relatively moved by a first driving means, and the machining head is vertically moved by a second driving means so as to move between the electrode and the workpiece. Is a shaft copying machining device for machining the work by controlling the gap to be always constant, the voltage detection device detecting an arc voltage output from the electrode to the work, and the voltage signal detected by the voltage detection device. A gap control device for inputting and controlling the gap, a monitoring device for monitoring the movement amount, the remaining movement amount or the movement time of either the machining head or the work by the first driving means, and the monitoring device for monitoring Based on the moving amount, the remaining moving amount, or the moving time, the drive signal of the second driving means from the gap control device is turned on or off. A shaft copying apparatus, comprising: switching means for FF.