JPS5944143B2 - Tracing processing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a tracing processing device capable of accurately tracing a target line consisting of a two-dimensional curve using an on-off type sensor and a potentiometer with a simple structure. Regarding.

A target line formed along a two-dimensional curve perpendicular to the generatrix of a workpiece consisting of a cylindrical surface having a two-dimensional curve as a conducting wire, for example, a welding device (welding robot) that performs arc welding following a welding line. Most of the methods were either mechanical, in which a tracing sensor installed to detect the welding line directly touched the welding line, or photoelectric or electromagnetic, in which it was tracked at close range.

Cyllundrical surface
is defined as a curved surface drawn by a moving line (generating line) that passes through each point on a constant curve C and is parallel to the constant straight line (
It is clear that the constant curve C is called a conducting wire.

Therefore, cylindrical surfaces are a general term for various shapes such as cylindrical surfaces, elliptical cylindrical surfaces, flat curved surfaces, etc. A typical example is a circular pipe such as a steel pipe. If we consider the case where right-angled flanges are integrated by back-jointing as shown in the figure, the weld line is attached to a curve (a specific conductor forming a circle) perpendicular to the generatrix of the steel pipe as a workpiece. This means that the situation is spreading.

However, in the conventional welding device described above, since the tracing sensor is located close to the welding torch and precedes it, there is a drawback that a complicated control device is required to take into account the deviation between the detection position and the welding position. It is also possible that the sensor may be damaged by the thermal effects of the arc, which is a problem that needs to be resolved in the case of automatic profile welding.

In order to cope with this fact, the present invention uses an on-off type sensor with a simple structure at a position remote from a target line such as a welding line, and further combines a potentiometer with the welding torch, etc. The present invention has led to the invention of a tracing processing device with a new structure that is capable of accurately tracing a tool along a target line, and a welding device of one embodiment will be described in detail with reference to the attached drawings. This will be explained in detail based on the following.

As shown in Figure 1, the workpiece 1 to be subjected to the welding process by the welding device is a round steel pipe 2 with a right-angled flange 3 welded to it, and the weld line t in this case is aligned with the pipe axis. It is clear that the shape is circular and perpendicular to the parallel generatrix. Therefore, by using a sensor to track the portion of the pipe wall that is parallel to the weld line t, it becomes possible to indirectly detect the weld line t at a remote location.

The structure of the welding device for welding the welding line t by arc welding is schematically shown in a basic skeleton form in FIG. A vertical axis z that has a degree of freedom; a left-right axis A front-back axis Y that is pivoted to have a degree of freedom in the horizontal direction (in the direction with respect to the workpiece 1); It has 4 axes of rotation, F, which performs an equidistant parallel revolution around a vertical reference axis perpendicular to the surface, consisting of the left-right axis X and the front-back axis Y, and is fixed in an upright position. The rotation axis F is provided so as to be able to rotate on the outside of the round steel tube 2 while the vertical axis Z and the reference value are both kept parallel to the generatrix of the round steel tube 2 of the work 1.

A welding torch 6 as a tool is pivotally attached to the tip of the rotating shaft F so as to be swingable in a vertical plane.

The vertical dimension of the vertical axis Z is adjusted by a driving source such as a motor 7, and the vertical displacement at this time is measured as an electrical displacement by a Z potentiometer 8. Front-rear axis Y
The left and right axis X constitutes the main axis of this device, and the left and right axis X is adjusted in its left and right dimensions by a drive source, for example, an electric motor 9, and the left and right displacement at this time is determined by the X potentiometer. The length is measured by the meter 10 as electrical displacement.

Further, the longitudinal dimension of the longitudinal axis Y is adjusted by a driving source such as an electric motor 11, and the longitudinal displacement at this time is measured as an electrical displacement by a Y potentiometer 12.

The rotational axis F is rotated by one driving source, for example, an electric motor 13, and the rotational displacement at this time is determined by the F potentiometer 1.
4, the length is measured as an electrical displacement corresponding to a clockwise rotation angle with respect to the longitudinal axis Y.

Note that the rotating shaft F is integrally connected to the reference shaft V via the horizontal arm 15, and rotates once on its axis for each revolution, so that the welding torch 6 attached to the end of the rotating shaft F is always connected to the workpiece. Needless to say, it has become possible to be oriented toward the 1st side.

Next, the welding torch 6 is swingably attached to the end of the rotating shaft F so that the tip can always be oriented on the extension of the reference axis V.

Is it possible to determine the height of the welding torch 6 based on the electrical displacement of the Z potentiometer 8 in the welding device configured as described above? Furthermore, it is possible to determine the relative position of the welding torch 6 with respect to the workpiece 1 by combining the three electrical displacements of the X potentiometer 10, the Y potentiometer 12, and the F potentiometer 14. Out.

It should be noted that the weld line t has a circular shape on a horizontal plane, and extends diagonally upward with the groove portion where overlay welding is performed.

The above-mentioned welding device includes a tracing sensor 17 and a
and a speed command device 21 are provided as displacement detectors.To explain the basic functions of both 17 and 21, the copying sensor 17 connects the welding torch 6 to the tactile part that is activated by directly touching the object. The welding torch 6 is oriented in the same direction as the welding torch 6.
It will be located near Kamiyaman.

The scanning sensor 17 is capable of emitting five different signals: a neutral state indicating a predetermined position, an overshoot correction, an overreturn correction, a clockwise direction correction, and a counterclockwise direction correction.

On the other hand, the speed command device 21 is composed of a known sine and cosine potentiometer, and detects the rotation angle of the reference axis V in the clockwise direction with respect to the longitudinal axis Y, and adjusts the rotation angle to the rotation angle. Both the corresponding sine output E8 and cosine output EO can be generated simultaneously, and are provided in relation to the reference axis V.

An example of the scanning sensor 17 is shown in FIG.
The basic structure is an on-off switch, and the switch 18A consists of an actuating piece 20A and a contact part 19A, and the switch 18B consists of an actuating piece 20B and a contact part 19B.
For example, the actuating pieces 20A, 20b are connected via a bullet so that they are attracted to each other, and are arranged in a line-symmetrical manner, so that the actuating pieces 20A, 20B are in contact with the object and their positions are appropriate. If so, both contact portions 19A, 19B will be in a neutral state in which they do not emit any signals, and the positions of the contact portions 19A, 19B may be incorrect, and may be too close or too far.
The open/close states of 19B are different, and it is possible to emit signals with ten different combinations as shown in Fig. 4.

3 and 4, if the tracing sensor 17 goes too far, that is, comes too close to the workpiece 1, the fourth
As shown in column O of the figure, in the contact part 19A, the contact 19AR and the movable contact piece are closed (indicated by the symbol ○), and in the contact part 19B
Then, the contact 19BR and the movable contact piece are closed.

In addition, when the relative positions of the actuating pieces 20A and 20B with respect to the workpiece 1 are in an unbalanced state, and when the actuating piece 20B is closer to the actuating piece 20A than the actuating piece 20A, as shown in FIG.
), 5. Three types of signals are output as shown in each column, indicating that clockwise correction is necessary, and conversely, when the actuating piece 20A is closer, Indicates that counterclockwise correction is required as shown in the 0 and 8 columns.

In this way, apart from the four standby states, the neutral state @, over-return correction (preceding instruction) O, over-return correction (backward instruction) O, clockwise rotation direction correction 1 to [F], counterclockwise rotation direction correction 7 to 9
Five types of signals can be emitted from the scanning sensor 17.

Next, the speed command 21 is a circular sine/cosine potentiometer, as shown in FIG. , two sliding contact pieces 22A, 22 with phase angles shifted by 90
B is integrally rotated by a reference shaft so as to be brought into sliding contact with the resistor.

9 in the clockwise direction based on the direction of the longitudinal axis Y.
1 potential is applied to the part where the transition occurred after 0, and e is applied to the part where the transition was made to 270.
By applying a potential, the preceding sliding contact piece 22B outputs an output E according to COsθ.

However, outputs E8 corresponding to Sinθ are respectively taken out from the following sliding contact pieces 22A, and the polarities of both signals are COsθ→1 and Sinθ→4 in the first quadrant 5 in FIG. 5, and in the second quadrant 5, the polarity is changed to COsθ→θ, Sinθ→1, in the third quadrant 8, COsθ→θ, Sinθθ→0, and in the fourth quadrant 4, COsθ→1, Sinθ→e, respectively. As is clear from the above principle, the speed command device 21 outputs a sine component E8 and a cosine component output E in accordance with the rotation angle of the reference axis V.

are taken out at the same time, and moreover, they are taken out in four combinations of polarities. The above-mentioned welding apparatus is equipped with a speed control circuit as a control circuit for performing automatic profile welding, and as shown in FIG. The cosine output E is given to the electric motor 11 on the longitudinal axis Y.

a speed command main circuit 23 that gives the electric motor 9 of the left and right axis X;
The speed correction circuit 24 provides a cosine output EO to the electric motor 11 and a sine output Es to the electric motor 9. The speed command main circuit 23 outputs a cosine component E.

A conversion switch 26A is provided in the transmission line of the switch 26A, and a cosine component output E is provided by switching the switch 26A. is directly transmitted with the current polarity, or is transmitted with the polarity inverted by the polarity inversion circuit 27A, and similarly, the conversion switch 26B and the polarity inversion circuit 27B are also transmitted to the transmission line of the sine component output Es.
It is designed to transmit the sine output E, either directly or with its polarity inverted. In addition, both conversion switch 26
A, 26B and bipolar inversion circuits 27A, 27B are the second
According to the second invention, a double changeover switch 26A
, 26B are arranged in relation to the F potentiometer 14, and are formed so as to alternately and repeatedly interlock and automatically switch at the upper limit position of a preset rotation angle range, for example around 3600. .

However, the conversion switches 26A and 26B may be made switchable by manual operation as appropriate, and the welding torch 6 may be turned in the clockwise direction C.
．． W or counterclockwise C. C. Of course, it is also possible to manually switch when it is desired to move W in any direction. On the other hand, the speed correction circuit 24
The fourth contact point 19AF and 19BF of 7 are both closed.
Contacts F, , F2 which are closed in the state shown in column 6, and Figure 4 where two contacts 19AR and 19BR are both closed [Yes]
The sensor is composed of contacts R,, R2, which are closed when the state shown in column 2, polarity reversal circuits 28A, 28B, and constant multiplication circuits 29A, 29B, and the contact Fl, F2 is closed, that is, the scanning sensor. State O where 17 is emitting an excessive return correction signal
So, the chordal output E.

is transmitted to the longitudinal axis Y with the same polarity as the output KleO, and the polarity of the sine component output E8 is reversed to output the output car K2e.
It is transmitted to the left and right axis X as S. On the other hand, when the contacts R, , R2 are closed, that is, when the scanning sensor 17 is emitting an overshooting correction signal, the cosine output EO is polarized and transmitted to the longitudinal axis Y as outputs K and eO, and The sine output Es is transmitted to the left and right axis Y with the same polarity as the output K2eS.

Next, the relationship between the signal and output of the scanning sensor 17 is expressed as follows.

(a) When the copying sensor 17 is in the neutral state 9, the speed correction circuit 24 outputs a sine component Es and a cosine component output E.

No communication is achieved. On the other hand, no rotation command is issued to the rotation axis F either. (b) When the copying sensor 17 is in the overshooting correction signal transmission state O, the speed correction circuit 24 outputs a cosine component E.

The polarity is reversed, and the sine component output E8 is directly applied to the front and rear axes Y.
and the left-right axis X. On the other hand, no rotation command is issued to the rotation axis F. (c) The scanning sensor 17 is in the state of sending an excessive return correction signal. Communicate to X.

On the other hand, no rotation command is issued to the rotation axis F. (d) In each state 1, (to), and (E) in which the copying sensor 17 is transmitting a clockwise direction correction signal, in the speed correction circuit 24, each contact Fl, F2, R, , R2 is all opened. Therefore, as in the case of the neutral state O, neither the sine component output E8 nor the cosine component output EO are transmitted.

On the other hand, when at least one of the contacts 19AF and 19BR is closed, a clockwise direction correction output (not shown) is given to the electric motor 13 to control the scanning sensor 17 to return to the neutral state. (e) States 7, 8, and 2 in which the copying sensor 17 is transmitting a counterclockwise rotation direction correction signal
In this case, the speed correction circuit 24 outputs a sine component Es and a cosine component output E, as in the above-mentioned 4th term.

On the other hand, the contacts 19AR and 19BF
When at least one of them is closed, a counterclockwise correction output (not shown) is given to the electric motor 13 to control the scanning sensor 17 to return to the neutral state. The outline of the profile welding means of the welding apparatus having the above-mentioned configuration will be explained below with respect to the case of the welder 1 in the form of welding the right-angled flange 3 to the round steel pipe 2.

The welding device is placed near the workpiece 1 as shown in Figure 2, and set so that the reference axis V is located closer to the workpiece 1 than the rotation axis F, and the longitudinal axis Y is aligned with the center axis of the workpiece 1. Furthermore, the stroke of the vertical axis z and the swing angle of the welding torch 6 are adjusted so that the welding torch 6 is oriented toward the bottom through the groove center line of the welding line t. Then, the origin alignment of the welding equipment is completed. Next, when the speed control circuit is activated to perform automatic profile welding, the welding device automatically moves to a position where the tactile part of the profile sensor 17 contacts the body wall of the round steel pipe 2 and maintains a neutral state at all times. It is possible to move the welding torch 6 along the welding line t at a constant aiming angle and at a constant speed while selecting the desired position.

Proper automatic profile welding is carried out in this way because the profile sensor 17 controls the rotation axis F to maintain a neutral state, and the speed control circuit controls the speed to a constant level. First, the constant speed control function will be explained by dividing it into a speed command and a speed correction command. (
1) When the speed command tracing sensor 17 is placed in the neutral state (Fig. 4 @ column), the welding torch 6 is correctly normal to the welding line t (the welding line t).

In order to move the welding torch 6 at a constant speed v along the welding line t from this neutral state where the rotation axis F is rotated by θ0 as shown in FIG. By giving the sine component Vsinθ to the longitudinal axis Y and the cosine component VcOsθ to the left-right axis X, their composition matches the velocity v.

Therefore, the speed command main circuit 23 always gives speed commands to both axes X and Y that correspond to the rotation angle θ and meet the above-mentioned conditions. It becomes possible to control the welding torch 6 to move at a constant target angle and constant speed by decomposing the composite speed V according to the neutral state angle θ and giving commands to both the X and Y axes, respectively. .

9 Speed correction command When the copying sensor 17 is in either an over-travel or an over-return state, an appropriate correction command is given respectively. If the copying sensor 17 returns too far in the range of
, 19BF are both 0N.

On the other hand, in the first quadrant 5, as is clear from FIG. 5, both the cosine output and the sine output output from the speed command device 21 are positive values.

Therefore, the horizontal axis X correction signal is -K2vsinθ, the longitudinal axis Y correction signal is K, vcOsθ, and the combination of the movements of both axes X and Y is in the direction approaching the tangent line t, as shown by the vector in Fig. 7. A correction speed command is issued, and correction is made so that the copying sensor 17 is in a neutral state.

Similar corrections are made for each of the other quadrants 5, (!11), and 4, and although the explanation of the overshooting correction state (Fig. 4 (d)) is omitted, the composite correction speed of the vector that is suitable for the correction is A command is issued and the scanning sensor 17 is operated to be regulated to a neutral state.

As described above, the speed command is appropriately issued in the neutral state, and the speed correction command is appropriately issued in each state of overshooting and overshooting, so that the welding torch 6 moves at a constant target angle and at a constant speed, resulting in a stable rear contact force control. done dynamically.

In the control circuit shown in Figure 6, if the changeover switches 26A and 26B of the speed command main circuit 23 maintain the state shown in the figure, the welding torch 6 always repeats clockwise rotation, and therefore the welding Multilayer overlay welding in the clockwise direction is possible by changing the swinging angle of the torch 6 for each rotation by an appropriate means.

On the other hand, each time the welding torch 6 rotates, the changeover switch 26
When A and 26B are reversed, the polarity of the sine and cosine outputs issued from the speed command device 21 is reversed, so that an appropriate speed command is issued according to the rotational direction. Reversible rotation method multi-layer overlay welding becomes possible.
Further, by switching the conversion switches 26A and 26B in the counterclockwise direction, it is also possible to perform multilayer overlay welding in the counterclockwise direction.

As is clear from the above description, the present invention
By simply providing the three degrees of freedom of the left-right axis The control system can also be simple, and the device can be provided compactly and at low cost. Furthermore, the detection elements for controlling the scanning speed only need to include two members: a scanning sensor 17 such as a simple on-off type, and a speed command device 21 using a sine/cosine potentiometer, and furthermore, it is sufficient to have two components: Since it is sufficient to control each of the two X axes one-dimensionally, the control system is extremely simplified compared to this conventional device.

In particular, since the scanning sensor 17 can be arranged at a location away from the force mark line t to detect the position, work efficiency is improved compared to conventional devices that detect the position near the tool 6. Not only is this improved, but it is also possible to prevent temporal deviation between the target position of the tool 6 and the detected position of the copying sensor 17, which has the advantage of easy and reliable control. The present invention is a highly practical tracing processing device.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of a workpiece to be processed by the apparatus of the present invention, FIG. 2 is a schematic structural diagram of an example of the apparatus of the present invention, and FIG. 3 is a schematic diagram of a scanning sensor in the apparatus of the present invention. Fig. 4 is a table of operating characteristics of the scanning sensor, Fig. 5 is a principle explanatory diagram of the output characteristics of the speed command device in the device of the present invention, Fig. 6 is a speed control circuit diagram of the device of the present invention, and Fig. 7 is a speed control diagram of the device of the present invention. FIG. 3 is an explanatory diagram of the operation of the control circuit. 1...Work, 5...Spindle, 6...Tool, 17
...Copying sensor, 21...Speed command device, 23...
Speed command main circuit, 24... Speed correction circuit, t... Target line, F... Rotation axis, V... Reference axis, X... Left and right axis, Y... Front and back axis.

Claims (1)

[Scope of Claims] 1. A device that moves a tool along a target line l formed along a curve perpendicular to the generatrix of a workpiece 1, which is made of a cylindrical surface having a curved line as a conducting wire, the said generatrix of the workpiece 1 It has two degrees of freedom, two axes X and Y that are orthogonal to each other and mutually orthogonal, with one axis Y being the front-rear axis in the direction of approaching and separating from the workpiece 1, and the other axis X being the left-right axis. A spindle connected to the spindle at the tip of the spindle so as to be able to rotate around a reference axis V that is orthogonal to the plane constituted by the two axes A moving axis F, a tool 6 swingably attached to the end of the rotating axis F with its tip facing the reference axis V, and a neutral state indicating a predetermined position, over-travel correction, over-return correction, and clockwise direction correction. A tactile section that emits five types of signals for correction of the clockwise rotation direction and counterclockwise rotation direction is oriented in the same direction as the tool 6 and fixed to the rotation axis F, and the clockwise rotation direction correction signal is for the clockwise rotation direction and the counterclockwise rotation direction. In the correction signal, the copying sensor 17 gives a command in the counterclockwise rotation direction to the rotation axis F, respectively.
a speed command device 21 that detects a rotation angle of the rotation axis F in a predetermined direction with respect to the longitudinal axis Y and outputs two outputs, a sine output and a cosine output corresponding to the rotation angle; It consists of a speed control circuit that gives speed commands to X and Y, and the speed control circuit converts the sine output of the speed command device 21 into
In response to the signals from the speed command main circuit 23, which similarly transmits the cosine output to the left and right axes X, and the scanning sensor 17,
In the neutral state, no output is transmitted, and in the overshoot correction signal, the cosine output is polarized and transmitted to the longitudinal axis Y, and the sine output is directly transmitted to the left and right axes X, respectively. The tool 6 is provided with a speed correction circuit 24 that directly transmits the sinusoidal output to the longitudinal axis Y and inverts the polarity of the sinusoidal output and transmits the sinusoidal output to the left and right axes X. A profiling processing device characterized by performing profiling control. 2. A device that moves a tool along target lines l formed along curves perpendicular to the generatrix of a workpiece 1 consisting of a cylindrical surface having curved conductors, each of which is orthogonal to the generatrix of the workpiece 1, and A main shaft having two degrees of freedom, two axes X and Y that are perpendicular to each other, and one axis Y is formed as a front-rear axis in the direction of approaching and separating from the workpiece 1, and the other axis X is formed as a left-right axis, A rotation axis F connected to the main shaft so as to be able to rotate around a reference axis V perpendicular to the plane constituted by the two axes X and Y at the tip of the main shaft, maintaining equidistant parallelism; A tool 6 is swingably attached to the end of the rotating shaft F with the tip facing the reference axis V, and a neutral state indicating a predetermined position, over-travel correction, over-return correction, clockwise rotation direction correction, and counterclockwise rotation direction correction. A tactile section that emits five types of signals is oriented in the same direction as the tool 6 and fixed to the rotation axis F, and the clockwise rotation direction correction signal indicates clockwise rotation, and the counterclockwise rotation direction correction signal indicates counterclockwise rotation. a tracing sensor 17 that gives a direction command to each of the rotational axes F;
a speed command device 21 that detects a rotation angle of the rotation axis F in a predetermined direction with respect to the longitudinal axis Y and outputs two outputs, a sine output and a cosine output corresponding to the rotation angle; It consists of a speed control circuit that gives speed commands to X and Y, and the speed control circuit transmits the sine component output of the speed command device 21 to the longitudinal axis Y, and similarly transmits the cosine component output to the left and right axis X, respectively, so that the polarity can be changed. Speed command main circuit 23 and the copying sensor 17
In response to the signal, no output is transmitted in the neutral state, and the polarity of the cosine output is reversed in the overshoot correction signal to the longitudinal axis Y.
And, the sine output is directly transmitted to the left and right axes X, respectively, and
The over-return correction signal is provided with a speed correction circuit 24 that directly transmits a cosine output to the longitudinal axis Y, and a speed compensation circuit 24 that inverts the polarity of the sine output and transmits it to the left and right sides X, respectively.
1. A profiling processing apparatus characterized in that the profiling control is performed with a constant aiming angle and a constant speed, and with a changeable direction of movement. 3. The speed command main circuit 23 in the speed control circuit is
At the upper limit position and lower limit position of the set rotation angle range of the rotation axis F, both the sine output and the cosine output,
3. The profiling processing device according to claim 2, wherein the profiling processing device is configured to be automatically switched between direct transmission and polarity inversion transmission by alternating repetitions.