JPH0321270B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fillet profile welding device, and in particular, when a notch (including a hole) is formed in a workpiece and the weld line is cut in the middle, the cut part The present invention relates to a device that can weld by following the welding line by skipping the welding line.

Conventionally, a traveling truck is provided with a welding torch and a welding line tracing sensor preceding the welding torch, and the position of the welding line is detected by detecting, for example, a horizontal work surface and a vertical work surface using the tracing sensor. A device is known in which the position of a torch is controlled vertically and horizontally to perform welding along a fillet weld line.

By the way, in the case where a notch is formed at the lower end of the workpiece, for example a vertical workpiece, and the fillet weld line is cut off in the middle, the conventional welding apparatus described above is capable of cutting the notch part along the Since it cannot be detected by a sensor, each time tracing welding for one continuous weld line is completed, the operator needs to transport and reposition the trolley to the starting end of the next continuous weld line,
The work was extremely tedious.

So, if you try to omit the troublesome work mentioned above,
In addition to the profiling sensor, a notch detection sensor is added, and when this detection sensor detects the starting end of the notch, the welding power is turned off, the profiling control is stopped, and the cart is only moved forward, and the detection It is conceivable that if the sensor detects the end of the notch, the tracing control is executed again and the welding power source is turned on. However, after the detection sensor detects the starting end of the notch, the cart does not necessarily move straight, but rather moves slightly closer to or further away from the vertical workpiece. Therefore, especially when the trolley travels at a distance, the detection sensor is also remote from the vertical workpiece, and a situation arises in which the detection sensor cannot detect the end of the notch. It is not possible to expect curved welding.

This invention was made in view of the above-mentioned circumstances, and even if a notch is formed in the workpiece and the weld line is cut off in the middle, the notch part can be
The present invention provides a device that controls the position of the welding point of the torch using a sequential program rather than tracing control, so that the welding point can be skipped over the notch and the broken welding line can be continuously and reliably welded. That is. Examples will be described in detail below.

W ₁ and W ₂ are workpieces, W ₁ is a horizontal workpiece, W ₂ is a vertical workpiece, and both workpieces
W ₁ and W ₂ are mutually positioned and tack welded in advance as shown in FIG. WH is work
This is a notch formed at an appropriate interval at the lower end of _W2 . WL (WL ₁ , WL ₂ , WL ₃ ) is for both workpieces
This is the horizontal fillet weld line formed by W ₁ and W ₂ .
WB is the butt weld bead of workpiece _W1 .

Reference numeral 1 denotes a traveling trolley (approximately square in plan view), on which a total of four wheels 2 are mounted. All wheels 2 are operated by electric motor M ₁ attached to the bottom of truck 1.
A chain 3a and sprockets 3b, 3c,
They are configured to be driven in the same direction via a power transmission mechanism 3 consisting of bevel gears 3d and 3e.
Although _E1 is not shown in detail, it is an encoder for detecting travel distance connected to the wheel 2. S1 is
This is a servo system including an electric motor _M1 and an encoder _E1 .

Reference numeral 4 denotes a steering mechanism, which is configured to be able to simultaneously steer all wheels 2 in the same direction and at the same angle via a chain 4a and sprockets _4b , 4c by an electric motor M2 attached to the bottom of the truck 1.
E ₂ is a steering angle detection encoder of the mechanism 4, although its details are not shown. S2 is a servo system including electric motor _M2 and encoder _E2 .

5 is vertically supported 5a at the upper center of the trolley 1,
It is a rotating body rotated by electric motor _M3 . _E3 is
Although not shown in detail, it is an encoder for detecting the rotation angle of the rotating body 5. S3 is a servo system including electric motor _M3 and encoder _E3 . 5b is
This is a handle fixed to the upper part of the rotating body 5.

6 is a movable body supported by the rotating body 5 and movable in the horizontal direction by an electric motor _M4 . _E4 is an encoder for detecting the position of the moving body 6. S4 is
This is a servo system including electric motor _M4 and encoder _E4 .

7 is a tilting member supported by the movable body 6 and tiltable up and down by an electric motor _M5 . _E5 is an encoder for detecting the tilt angle of the member 7. S5 is a servo system including electric motor _M5 and encoder _E5 .

Reference numeral 8 denotes a welding torch support member supported by member 7 and rotated approximately horizontally about a shaft 8a by an electric motor _M6 . _E6 is an encoder for detecting the rotation angle of the member 8. S6 is electric motor _M6
and a servo system including encoder _E6 .

SH is supported by the member 8, and is a horizontal direction tracing sensor (contact type in the embodiment) for the welding line WL;
It includes a contact 9 which is connected 9a to the member 8 and urged to protrude by a spring 10, and a differential transformer _TR1 connected to the contact 9. Note that the sensor SH is set so that the shaft 8a passes through the tip of the contact 9 at the protruding position of the contact 9 at a preset reference output value. Further, the protrusion of the contactor 9 is limited by a stopper 8b.

SV is supported by member 7 and is a vertical tracing sensor (contact type in the embodiment) for welding line WL;
Contactor 11 urged to protrude by a spring (not shown)
and a differential transformer TR ₂ connected to the contactor 11. Note that the sensor SV is set so that the member 7 is in a horizontal position at the protruding position of the contactor 11 at a preset reference output value.

T is a welding torch attached to member 8;
The mounting position of the torch T is such that the welding point P of the torch T is at the protruding position of the contacts 9 and 11 at the reference output values of the sensors SH and SV.
It is set to be located below the tip and on a horizontal plane passing through the tip of the contactor 11.

SS is a workpiece notch detection sensor that precedes the sensor SH, and in the embodiment, the contact 9 of the sensor SH
A contact 12 which is connected to 12a and urged to protrude by a spring 13, and a limit switch LS that detects the rotational position of this contact 12 (ON in the state shown in Fig. 3)
including.

14 is a conduit cable including a signal cable, a power cable, a power supply cable to the torch T, and the like.

SW (SW ₁₁ , SW ₁₂ , SW ₂₁ , SW ₂₂ , SW ₃₁ ,
SW ₃₂ , SW ₄₁ , SW ₄₂ ) are limit switches, two of which protrude from each of the four sides of the truck 1, for a total of eight limit switches, and are capable of detecting a collision of the truck 1 with the workpiece W ₂ .

C is a control unit mainly composed of a computer including a central processing unit CPU and a memory MEM. The control device C includes each servo system S1 to S6 and an operation panel.
REM, welding power source WS, transformers TR ₁ and TR ₂ , and switches LS and SW are connected via bus line B.

In addition, the control device C has the following functions: (a) By outputting the notch WH start end information from the sensor SS, it turns off the power supply WS and cancels the tracing control by the sensor SH, and also outputs the notch WH starting edge information from the sensor SS.
a first means F1 for counting the traveling distance or traveling distance (traveling time in the embodiment) of the bogie ₁ from the starting end; (b) an output signal of the notch WH termination information from the sensor SS; and the first means Count value t at F ₁
Compare the signal that is output when exceeds a certain value t ₀ (corresponding to the time during which the trolley 1 can travel a distance slightly longer than the length of the notch WH) and which one is output faster. ( _c ) If the output signal of the notch WH termination information is earlier, the traveling of the trolley 1 is stopped based on that signal, and the member 8 is moved a certain distance or for a certain period of time ( In the example, the welding line is
The trolley 1 is moved remotely from WL, and further moved forward for a certain distance or a certain period of time (a certain period of time in the example), and furthermore, to a position where the sensor SH can detect the welding line WL (workpiece W ₂ in the example). A third means _F3 for moving the member 8 close to the welding line WL (workpiece _W2 ); and (d) conversely, if the signal indicating that the count value t exceeds the constant value _t0 is earlier. , a fourth means F 4 is provided to move the member 8 close to the welding line WL (workpiece W ₂ ) to a position where the sensor SH can detect the welding line WL (workpiece W ₂ in the embodiment) based on the signal _. and .

Furthermore, the operation of this embodiment will be described.

First, the operator turns on the power switch and origin positioning switch (not shown) on the operation panel REM.
Make it. At this time, the steering angle of the wheels 2 is such that all the wheels 2 are in the longitudinal direction (X direction), and the rotating body 5 is
is at a position where the moving direction of the movable body 6 is in the left-right direction (Y direction) with respect to the cart 1, and furthermore, the movable body 6 is
is at a position where the output value of transformer TR ₁ matches the preset reference output value, and furthermore, member 7 is
The member 8 is positioned at a position where the output value of the transformer TR ₂ matches a preset reference output value, and at a position where the torch angle with respect to the X direction (approximately in the direction of the welding line WL) is optimal. .

Then, the operator holds the handle 5b and places the trolley 1 on the workpiece _W1 as shown in FIG. , SV, and SS contacts 9, 11, and 12 are the workpieces W ₁ and W ₂ , respectively.
Determine the starting position so that it touches the

When the start switch (not shown) on the operation panel REM is turned on, a command is first output to turn on the power source WS (step ST ₁ ), and a command is also sent to the electric motor _M1 to move the trolley 1 forward at a preset welding speed. is output (step ST ₂ ), and at this time the encoder
Counting by _E1 is started (step _ST3 ).

Then, the moving body 6 and the member 7 are detected by the sensors SH and SV.
Profile welding is performed while controlling the position of the welding point P of the torch T to match the welding line _WL1 .

In other words, the output value from transformer TR ₁ is taken into the CPU, and the difference between this value and the reference value is calculated (step
ST ₄ ), determine whether the difference is positive or negative (step
ST ₅ ), and if the difference is positive, move the moving body 6 to the workpiece at a speed corresponding to the difference, as shown in Figure 7 A.
A command is output to the motor _M4 to remotely move the workpiece _W2 , and conversely, if the difference is negative, the moving body 6 is moved at a speed corresponding to the difference, as shown in FIG. 7A. A command is output to electric motor _M4 to move it closer to point ₂ (step _ST6 ).

In addition, the output value from transformer TR ₂ is taken into the CPU, and the difference between this value and the reference value is calculated (step
ST ₇ ) and determine whether the difference is positive or negative (step
_ST8 ). And if the difference is positive, the difference is the value a
It is determined whether or not it is larger (step ST ₉ ), and if it is larger, a command is output to the electric motor M ₅ to remotely tilt the member 7 from the workpiece W ₁ at a constant speed as shown in FIG. 7 (b) (step ST ₁₀₎ . ), on the other hand, if it is small, proceed to the next step _ST13 . If the difference in step ST ₈ is negative, it is determined whether the difference is smaller than the value b (step ST ₁₁ ), and if it is smaller, the member 7
A command is output to the electric motor _M5 to approach and tilt the workpiece _W1 at a constant speed as shown in Fig. 7B (step _ST12 ).On the other hand, if it is small, the next step _ST13
Proceed to.

In this case, between the values a and b, the member 7
is in a stopped state, so even if the output value of transformer TR ₂ changes slightly because the wheel 2 rides on a protrusion such as the welding bead WB, the position P of the welding point will not change from the welding line WL ₁ . There's no way you'll be separated from the top.

In this way, by steps _ST1 to _ST12 , the welding line _WL1 is welded in a direction from the lower right to the upper left in FIG.

Then, at step ST ₁₃ , the switch LS
Determine whether it is turned off. As a result of the judgment, if switch LS is turned OFF, step ST ₁₄
Execute the contents of the subroutine described later, and if not, check whether the counter value by encoder _E1 has reached N in the next step _ST15 .
In other words, it is determined whether the trolley 1 has traveled from the start to the end of the welding line WL, and if the count value has not reached N, the process returns to step _ST4 .
Each step described above will be repeated. When the count value reaches N, a command is output to turn off the power source WS (step ST ₁₆ ), and a command is output to the motor M ₁ to stop the truck 1 (step ST ₁₇ ).

Although not detailed, during the profile welding mentioned above,
The position information of the welding point is taken into the CPU at regular intervals (for example, 0.1 seconds), and the direction of the welding line WL is calculated sequentially from that information, and the calculated welding line
The torch angle is controlled by rotating the member 8 around the axis 8a so that the angle of the torch T with respect to the direction of WL is constant, and the distance between the trolley 1 and the welding line WL is approximately constant. The wheels 2 are steered and the rotational speed of the wheels 2 is also controlled so that the welding speed is constant.

(b) By the way, in step ST ₁₃ , switch LS
The contents of the subroutine when the switch is turned off will be explained below. When the switch LS is OFF, that is, the contact 12 changes from the state shown in Fig. 4 (a) during profile welding to the notch shown in Fig. 4 (b).
When the welding reaches the WH starting point, a command is output to turn off the power source WS (step ST ₁₈ ), and welding is temporarily stopped. Furthermore, a command is output to the electric motors M ₂ , M ₄ , and M ₆ to stop all steering of the wheels 2, movement of the movable body 6, and rotation of the member 8 (step ST ₁₉ ), and further, the above-mentioned step ST ₇ The same contents as in ~ _ST12 (vertical tracing control of the member 7) are executed in steps _ST20 ~ _ST25 .

Therefore, as a result of steps ST ₁₈ to ST ₂₅ , member 7
The bogie 1 moves forward in the steering direction at the time of the steering stop while being controlled in a manner similar to the vertical movement. Therefore, even if the workpiece _W1 is bent up or down, the position of the contact 12 is always at a height where the notch WH can be detected.

(b) Then, it is determined whether the switch LS has been turned ON (step ST ₂₆ ), and if it has not been turned ON, the value of the time counter is set to (t=t+1) (step ST ₂₇ ). Furthermore, it is determined whether the value t of the counter is {t>t ₀ (constant value)} (step ST ₂₈ ), and if the result is (t<t ₀ ),
Return to step ST ₂₀ and execute the contents of each subsequent step.

Note that steps ST ₁₃ , ST ₁₈ , ST ₁₉ and ST ₂₇
corresponds to the first means _F1 . Also step ST ₂₆
~ _ST28 corresponds to the second means _F2 .

(c) If the switch LS in step ST ₂₆ turns ON earlier than the time counter value in step ST ₂₈ becomes (t>t ₀ ), that is, if the contact 12 turns on as shown in FIG. Spring 13 from the state
After it has completely fallen into the notch WH, the contact 12 contacts the end of the notch WH and retracts against the spring 13, and the switch LS is turned ON again. If it's summer,
First, a command is output to electric motor _M1 to stop truck 1 (step _ST29 ).

Therefore, as a result of steps ST ₁₈ to ST ₂₉ , trolley 1
The vehicle will travel from point A ₁₁ to point A ₁₂ in FIG. 5A, for example.

Next, a command is output to the electric motor _M4 to remotely move the movable body 6 from the workpiece _W2 at a constant speed (high speed) (step _ST30 ). The movement of the moving body 6 in this step ST ₃₀ is executed for a certain period of time (approximately 0.5 seconds), and when that time has elapsed (step ST ₃₁ ), a command is output to the electric motor M ₄ to stop the moving body 6. (step)
_ST32 ).

Therefore, as a result of steps _ST30 to _ST32 , only the moving body 6 moves from point _A12 to point _A13 in FIG. 5A.

Next, a command is output to the electric motor M1 to move the cart ₁ forward at a constant speed (welding speed) (step _ST33 ). The carriage 1 travels for a certain period of time (approximately 2 seconds) in step ST ₃₃ , and when that period of time has elapsed (step ST ₃₄ ),
A command is output to electric motor _M1 to stop truck 1 (step _ST35 ).

Therefore, as a result of steps ST ₃₃ to ST ₃₅ , trolley 1
will run from point A ₁₃ to point A ₁₄ in Figure 5A. At this time, the previous moving object 6 was at point A ₁₃
Contacts 9 and 12 have been immersed and moved up to
is caught on the workpiece W ₂ at the end of the notch WH,
This embodiment does not cause any trouble to the profile welding equipment.

Next, move the moving body 6 to the work W ₂ at a constant speed (low speed)
A command is output to electric motor _M4 to move it closer (step _ST36 ). Furthermore, the same contents as steps _ST7 to _ST12 (vertical tracing control of member 7) are executed in steps _ST37 to _ST42 . Then, it is determined whether the difference between the output value from _the transformer TR ₁ and the reference value has become 0 (step ST ₄₃ ). If it has not become 0, return to step _ST37 , and if it has become 0,
A command is output to electric motor _M4 to stop moving body 6 (step _ST44 ).

Therefore, as a result of steps _ST36 to _ST44 , only the moving body 6 moves from point _A14 to point _A15 in FIG. 5A. During this time, the member 7 is controlled in the vertical direction, so at the point _A15 , the position P of the welding point of the torch T is aligned with the welding line.
It will match WL ₂ .

Note that steps _ST29 to _ST44 correspond to the third means _F3 .

After that, the time counter value t is (t=0)
Then, a command is output to the motor M1 to move the trolley ₁ forward at the welding speed (step _ST46 ), and a command is sent to turn on the power _supply WS (step _ST47 ).
Returning to ST ₄ , welding line WL ₂ is welded by the tracing control in the horizontal, vertical, and horizontal directions described above.

(d) Switch LS of step ST ₂₆ is ON again
If the time counter value at step ST ₂₈ reaches (t > t ₀ ) earlier than when the time counter value reaches (t > t 0 ), that is, at the time of FIG. , if the contactor 12 cannot detect _the end of the notch WH as shown _{in FIG} . The process is executed.

Therefore _, as a result _of steps ST ₃₅ to ST ₄₄ , as _shown in FIG _. I will do it.

Note that steps _ST36 to _ST44 correspond to the fourth means _F4 .

Then, as in C above, welding line WL ₂ is welded by tracing control in the horizontal and vertical directions.

As above, cut out the bottom of workpiece _W2 .
Skip WH point and each weld line WL ₁ , WL ₂ ,
WL ₃ ... can be welded continuously.

Hereinafter, a case will be briefly described in which, for example, the workpiece W ₂ is in the form of a grid, the welding line WL is bent at 90 degrees, and this refraction welding is also continuously welded.

In this case, based on the output signal from the switch SW, the position of the rotating body 5 and moving body 6, the position of the wheel 2
The steering angle and the rotational direction of the wheels 2 are controlled by a predetermined sequential program, and the bending points are welded as follows.

First, the cart 1 collides with the workpiece W ₂ as shown in Fig. 9A, and when either switch SW ₁₁ or SW ₁₂ outputs a signal, the cart 1 is stopped and the rotating body 5 is rotated to the right by a certain angle. be done. At this time the 9th
Welding line WL between torches T and T′ in Figure A
It is welded in a straight line. Next, the power supply WS is turned off, and the movable body 6 is moved to the above-mentioned origin position. At this time, the torch T is at the position shown by the solid line in FIG. 9B. Then, the truck 1 is retreated a certain distance to position 1' in FIG. 9B, and the rotating body 5 is further rotated to the right by a certain angle. At this time, the torch T is at the T″ position in FIG. 9B, that is, at a position rotated 90 degrees to the right from the solid line position in FIG.
The contactor 9 is pressed against the work W ₂ and the transformer
The truck 1 is advanced to the position where the output value of TR ₁ matches the reference value, and eventually reaches the position shown by the solid line in FIG. 9C. Next, the wheels 2 are steered 90 degrees to the right, and the truck 1 is further moved backward. Then, finally, trolley 1
collides with the workpiece W ₂ as shown by _the two _- dot chain line in FIG. Therefore, at this point, the attitude of the truck 1 is such that the longitudinal direction of the wheels 2 and the vertical welding line WL in FIG. 9 are exactly at right angles. Next, the rotating body 5 is rotated to the left by a certain angle. At this time, the torch T is at the position indicated by the solid line in FIG. Also, during this meeting, sensors SH and SV
Tracing control is also performed. And power supply W
is turned ON again, and the rotary body 5 is rotated to the right by a certain angle, and the welding line WL between the torches T and T' in FIG. , the continuous part of the weld line WL is welded following the pattern.

In this way, it is possible to weld by following the bending point of the welding line WL.

The above explanation is an example, and if there is no need to continuously weld the bending part of the weld line WL,
The rotating body 5 may be omitted and the movable body 6 may be directly supported on the trolley 1. Moreover, if the welding line WL is almost a straight line, the movable body 6 is used as a support member, and the torch T,
Sensors SH and SS may be directly supported. Furthermore, the sensor SS may be installed on the member 8 instead of the sensor SH. It goes without saying that the technical scope of the present invention also includes the replacement of each component with equivalents.

As described above, in this invention, when the sensor SS detects the starting end of the notch WH, the power supply WS is turned off based on the output signal, and furthermore, the trolley 1 and the moving body 6 are sequentially controlled to control the welding point of the torch T. The position P is the weld line cut by the notch WH.
From WL ₁ to WL ₂ , and then from WL ₂ to WL ₃ ,
Since the notch WH location was skipped to enable position control, one continuous weld line was
This eliminates the need for the operator to carry the trolley 1 to the next welding line WL and position it each time the profile welding for the WL is completed. Further, the second means _F2 allows the sensor SS to detect the end of the notch WH, and the sensor SS to detect the end of the notch WH.
The count value t of the travel distance or travel time of the bogie 1 after detecting the WH start point exceeds a certain value _t0 , and which is faster.
If the WH end detection is faster, that is, if the sensor SS is fortunate enough to detect the notch WH end,
In order to perform sequential control like the third means _F3 , conversely, if the count value t exceeds the constant value _t0 sooner, that is, the sensor SS is notched.
If the WH termination cannot be detected, use the fourth method.
Since sequential control such as F ₄ is to be executed, in any case, the position P of the welding point of the torch T can be brought to the welding line WL that is continuous to the end of the notch WH, and the welding line WL is also Can be reliably welded. As a result, many notches WH are formed, and one continuous weld line WL ₁ , WL ₂ ,
For example, when a large number of WL ₃ ... are lined up in a straight line, the device of the present invention is very effective in actual work.

[Brief explanation of drawings]

Each of the figures shows an embodiment of the present invention.
The figure is an overall perspective view, Figure 2 is a bottom view of the traveling truck, Figure 3 is an explanatory diagram of the horizontal weld line tracing sensor and workpiece notch detection sensor, and Figure 4 is an explanatory diagram of the operation of the workpiece notch detection sensor. Fig. 5 is an explanatory diagram of the jumping locus of the notch, Fig. 6 is a block diagram of the control device, Fig. 7 is a velocity diagram of the moving body and tilting member in profile control, Fig. 8 is a flowchart,
FIG. 9 is an explanatory diagram of the effect on the refracted weld line. In the figure, W ₁ ... horizontal workpiece, W ₂ ... vertical workpiece, WB ... butt weld bead, WH ... notch, WL (WL ₁ , WL ₂ , WL ₃ ...) ... fillet weld line, T...Welding torch, P...Position of welding point of torch T, 1...Traveling trolley, 2...Wheels, 5
... Rotating body, 6... Moving body, 7... Tilting member, 8
...Welding torch support member, SH...Welding line horizontal direction tracing sensor, 9...Contact, SV...Welding line vertical direction tracing sensor, 11...Contact, SS
... Workpiece notch detection sensor, 12 ... Contactor,
LS...Limit switch, C...Control device, WS
... Welding power source, F ₁ ... First means, F ₂ ... Second means, F ₃ ... Third means, F ₄ ... Fourth means.

Claims (1)

[Scope of Claims] 1. A traveling truck, a welding torch support member supported by the truck and movable at least in the left-right direction, a welding line left-right direction tracing sensor protruding from this supporting member, and a welding line tracing sensor preceding the tracing sensor. a workpiece notch detection sensor, and a control device to which the outputs of both of the sensors are input; and stopping the tracing control by the tracing sensor,
(b) a first means for counting the travel distance or travel time of the cart from the notch starting end; (b) an output signal of notch end information from the notch detection sensor and the count value exceeding a certain value; (c) if the output signal of the notch termination information is earlier, a second means for comparing the output signal when the notch termination information is outputted is faster; The traveling of the truck is stopped, the support member is remotely moved from the welding line by a certain distance or a certain time, and the truck is moved forward by a certain distance or a certain time, and furthermore, the profiling sensor (d) when the output signal indicating that the count value exceeds the certain value is earlier, the output signal indicates that the count value exceeds the certain value; A fillet profile welding device comprising: fourth means for moving the support member close to the weld line to a position where the profile sensor can detect the weld line based on a signal.