JP4475603B2 - Copy welding equipment - Google Patents

Description

  The present invention relates to an automatic copying apparatus that automatically detects a groove between two materials to be welded or a corner formed by the two materials and causes the welding region to follow the torch.

JP-A-7-116846 Japanese Patent Laid-Open No. 9-253854 JP-A-11-207462 JP-A-6-335773.

  For example, in the construction of hulls in shipbuilding, in the manufacture of bridges, in the construction of large tanks, or in the manufacture or construction of other steel structures, the gaps between the two abutted steel plates or the two steel plates that intersect When welding the corners between the corners, the welding carriage is run along the welding line (groove or the direction in which the corner extends) while welding is performed, and the welding line is mounted with the welding torch mounted on the carriage. Automatic welding. In some cases, oscillation welding (oscillation) welding is performed in which the welding torch is driven back and forth in a direction perpendicular to the welding line to form a wide bead width. This type of welding is often performed over long distances, and as welding progresses (the welding process becomes longer), the welding target position of the welding torch is orthogonal to the weld line from the target position set at the start of welding. May be displaced in the direction of welding, resulting in poor welding due to bead displacement. Therefore, it is necessary to perform position control (copying control) of the welding torch in accordance with the position and shape of the groove so that the intended position of the welding torch is always directed to the predetermined position of the groove.

  In order to solve such a problem, there is a copying method using a touch sensor among conventionally known methods. This is because before welding is performed, the welding carriage is driven along the groove (y direction), and the groove width (x direction) and position (center position: x direction) are measured using a touch sensor attached to the welding carriage. ) And align the oscillation center position of the welding torch with the center position of the groove. In Patent Document 1, two contacts are supported at both ends of an arm, an intermediate point of the arm is supported by a rotating shaft, a potentiometer for detecting a rotation angle and an electric motor are connected to the rotating shaft, and the arm is reciprocally rotated. Thus, groove position detection is disclosed in which a rotation angle when each contact contacts the groove surface is detected to calculate a groove center position. In Patent Document 2, a sensor wire is reciprocated in the groove width direction by a sensor oscillation mechanism, and each oscillation position when the sensor wire comes into contact with one side and the other side of the groove surface is detected. , And a copy welding apparatus that adjusts the center position of torch saturation to the groove center position is disclosed.

  As a copying method using an arc sensor, the welding torch is oscillated in the groove width direction x in the groove groove during welding, the change in arc voltage with respect to both wall surfaces of the groove is measured, and the value is opened from that value. The position of the both wall surfaces (x) is separated, and the welding torch position is corrected so that the center of the oscillate is aligned with the intermediate point between the wall surface positions (x) (usually the groove center). In addition, an optical direction in which a groove is photographed with a camera and the groove width and position are calculated by image processing, and a method using a non-contact sensor such as a displacement meter instead of a touch sensor have been proposed (for example, patents). References 3 and 4).

  The touch sensor has a simple structure and is easy to maintain, and since the replacement cost is low, the use operation of the welding machine is simple and the maintenance before and after use is easy. However, since one groove width is detected by one reciprocating drive or one reciprocating rotation of the sensor wire or contact mounting arm, it takes time to detect one groove center position. If the reciprocating motion is continuously continued during the traveling of the carriage, the sensor oscillation mechanism is consumed quickly, and there is a possibility of causing resonance or interference in the torch oscillation.

  The first object of the present invention is to provide an inexpensive automatic copying welding apparatus, and a second object of the present invention is to provide an automatic copying welding apparatus that can be easily maintained for maintaining high scanning accuracy.

(1) A carriage (20) that travels in a direction y in which a groove between two materials to be welded or a welding region (Ow) that is a corner formed by the two materials extends;
A torch (32L, 32T) mounted on the carriage for welding the welding region;
A torch drive mechanism (30L, 30T) for supporting the torch on the carriage and driving in the x direction crossing in the y direction;
Mounted on the carriage, positioned upstream of the torch with respect to the carriage movement direction at the time of welding, and simultaneously contacting both of the two welding objects in the welding region at the same position in the carriage movement direction (y). The torch (32L, 32T) and the torch for detecting the contact (1) capable of supporting the contact and the movement of the contact in the x direction and the movement in the z direction crossing both the x and y directions A contact sensor (1, 2) comprising an x, z movement detector (2) separate from the drive mechanism (30L, 30T );
A sensor drive mechanism (23, 21) that is separate from the torch drive mechanism (30L, 30T) and supports the x, z movement detector and drives in the x, z directions;
X, z drive instruction signals (Sxup / Sxdown, Szup / Szdown) instructing driving in the same direction as the movement direction detected based on the x, z movement detection signals (A to D) of the x, z movement detector. Sensor scanning control means (3-11x, 3-11z) for driving the x, z movement detector via the sensor driving mechanism;
In response to the x drive instruction signal (Sxup / Sxdown) generated by the sensor scanning control means, the torch driving mechanism (30L, 30T ) is provided separately from the sensor scanning control means (3-11x, 3-11z). ) Torch copying control means (6L-15L, 6T-15T) for shifting the position of the torch in the x direction via
A copying welding apparatus comprising:

  In addition, in order to make an understanding easy, the code | symbol of the corresponding element or the corresponding matter of the Example which is shown in drawing and mentioned later in parentheses was added as an example for reference. The same applies to the following.

According to this, the sensor drive mechanism (23, 21) and the sensor scanning control means (3 to 11x, 3 to 11z) connect the x and z movement detector (2) supporting the contact (1) to the contact. The child (1) is driven in x and z so that both of the two materials to be welded (each of the facing groove surfaces) are simultaneously in contact with each other in the welding region (for example, a groove).
For example, when the contact (1) moves to a welding location (y position) where the groove is displaced in the width direction, for example, the right (+ x) direction with respect to the traveling direction (y) of the welding welding carriage (20), the left groove surface Thus, the contact (1) is pushed in the upper right direction (+ z, + x). When the upward / rightward movement of the contact (1) due to this is a set value (for example, 0.5 mm in any direction) or more, the x and z movement detector (2) detects the right movement detection signal (x drive instruction signal Sxup), An upward movement detection signal is generated, and the sensor driving mechanism (23, 21) and the sensor scanning control means (3 to 11x, 3 to 11z) drive the x and z movement detector (2) in the right direction and the upward direction. . That is, the sensor is driven to follow. This is a retreat drive for returning the contact (1) to the reference posture with respect to the x, z movement detector (2). As a result, when the contact (1) assumes the reference posture with respect to the x, z movement detector (2), the right movement detection signal and the upper movement detection signal disappear. During a period in which such a movement detection signal is not generated (a period in which the contact (1) is in the reference posture with respect to the x, z movement detector (2)), the sensor drive mechanism (23, 21) does not move. In other words, the reciprocating drive for detecting the groove width of the x, z movement detector (2) is unnecessary. The sensor drive mechanism (23, 21) is driven only at a position where the groove position is displaced, the operation time of the mechanism is very short, and the mechanism is less consumed. The life of the sensor drive mechanism (23, 21) is extended.

  Nevertheless, the x and z movement detector (2) automatically detects the position shift at a position where the groove is displaced with respect to the traveling direction (y) of the welding carriage (20). Signals (the right movement detection signal and the upward movement detection signal) are generated. When the right movement detection signal (x drive instruction signal Sxup) is generated, the torch copying control means (6L to 15L, 6T to 15T) responds to the x movement of the torch via the torch drive mechanism (30L, 30T). The direction position is shifted to the right (+ x) direction. As a result, the torch position is shifted in a direction in which the groove is displaced with respect to the traveling direction (y) of the welding carriage (20). In other words, the detection of the groove position deviation is reliably realized without delay, so that high-accuracy profiling welding can be realized. Since the contact sensor (1, 2) including the contact (1) and the x, z movement detector (2) that supports it is used, sensor maintenance and sensor replacement can be performed easily and at low cost. it can.

(2) The sensor drive mechanism (23, 21) includes an x drive electric motor (Mxs), a z drive electric motor (Mzs) for driving the x and z movement detectors forward and backward in the x and z directions, And each rotation amount detecting means (Pxs, Pzs) for generating a rotation amount signal representing a rotation amount increasing or decreasing by forward or reverse rotation of each electric motor (FIG. 4);
The sensor scanning control means (3 to 11x, 3 to 11z) generates x and z target position signals and moves the x and z in the same direction while the x and z movement detector detects the x and z movements. Means (Ctxp, Ctzp) for updating the level of the x and z target position signals in a stepwise manner in order to drive the detector (2), and the rotation amount signals generated by the respective rotation amount detection means Feedback control means (10x, 11x; 10z, 11z) for driving each electric motor in a direction matching the position signal (FIG. 4);
The copying welding apparatus according to (1) above.

(3) The sensor drive mechanism (23, 21) includes an x-drive electric motor (Mxs) and a z-drive electric motor (x, z) that drive the x, z movement detector (2) forward and backward in the x and z directions, respectively. Mzs);
The sensor scanning control means step-drives the x, z driving electric motors (Mxs, Mzs) in response to the x, z drive instruction signals (Sxup / Sxdown, Szup / Szdown) generated by the sensor scanning control means. Including motor drivers (11x, 11z) (FIG. 10);
The copying welding apparatus according to (1) above.

  (4) The torch drive mechanism (30L, 30T) is a swing mechanism that repeatedly drives the torch in the x direction, and the torch copying control means (6L-15L, 6T-15T) The profile welding apparatus according to any one of (1) to (3), wherein the center position of the reciprocating drive is shifted in response to (Sxup / Sxdown).

(5) The torch drive mechanism (30L, 30T) includes an electric motor (MxL, MxT) that reciprocally drives the torch in the x direction, and a rotation amount that indicates a rotation amount that increases or decreases by forward or reverse rotation of the electric motor. A rotation amount detecting means (PxL, PxT) for generating a signal;
The torch copying control means (6L to 15L, 6T to 15T) is a means (OtL, OtT) for generating a target position signal that defines a movement trajectory of the reciprocating movement of the torch (32L, 32T) in the x direction, the rotation amount Feedback control means (10L, 11L; 10T, 11L) for driving the electric motor in a direction in which the rotation amount signal generated by the detection means matches the target position signal, and the x drive generated by the sensor scanning control means Adjustment means for adding an adjustment for shifting the center position of the reciprocating movement of the torch in the same direction as the movement direction of the contact in response to the instruction signal (Sxup / Sxdown) to the target position signal or the rotation amount signal ( SaL, AdL; SaT, AdT);
The copying welding apparatus according to (4) above.

  (6) The adjusting means (SaL, AdL; SaT, AdT) is configured to stepwise with a predetermined cycle while the x drive instruction signal (Sxup / Sxdown) generated by the sensor scanning control means continues. The profile welding apparatus according to (5), wherein an adjustment value added to the target position signal or the rotation amount signal is updated.

  (7) The contact (1) has two pins lined up in the x direction, the tips of which are opposed to the two materials to be welded in the welding region (Ow). The copy welding apparatus as described in any one of 1).

  Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

  FIG. 1 is a plan view of the first embodiment of the present invention, FIG. 2 is a left side view, and FIG. 3 is a front view. 1 to 3 and the drawings referred to below, the -x arrow direction is the left side, the + x arrow direction is the right side, and the y arrow direction is the welding direction (the traveling direction of the carriage during welding) ( The opposite direction is backward), and the + z arrow direction is upward and the -z arrow direction is downward.

  Referring to FIGS. 1 to 3, two workpieces WL and WR (FIG. 3), which are thick steel plates, are arranged on the left and right sides, and a V-shaped groove (welding region) Ow between the workpieces WL and WR. Is formed. In this embodiment, the welding apparatus performs welding in the y direction along the rail 40 with the center position in the width direction x of the groove Ow as a target position for welding. The welding apparatus is one in which the two preceding and following welding torches 32L and 32T are mounted on the carriage 20 in the state of being arranged in the y direction, and the carriage 20 is moved in the y direction while performing welding on both welding torches. The two-tiered weld bead is realized by one run. A rail 40 extending in the y direction along the groove Ow is previously laid on the upper surface of the left workpiece WL. The carriage 20 has wheels 41 to 44 that run on the rail 40.

  Although not shown, a driven sprocket wheel is fixedly attached to the front wheel shaft at the bottom of the carriage. A carriage drive motor is fixedly supported on the carriage frame, a drive sprocket wheel is fixed to the rotating shaft thereof, and a drive chain coupled thereto is connected to the driven sprocket wheel. Further, at the rear of the carriage frame, there is a rear wheel shaft that extends in the x-direction, firmly supports the right rear wheel 43 and the left rear wheel 44 at both ends, and further has a driven sprocket wheel fixed integrally therewith. A driven chain of the front wheel shaft and the driven chain of the front wheel shaft are coupled to transmit the rotation of the front wheel shaft to the rear wheel shaft. When the cart drive motor is energized in the forward direction, the front wheel shaft and the rear wheel shaft are rotated along with the rotation of the rotation shaft, and the four wheels 41 to 44 are rotated at the same time, and the cart 20 moves forward (y). Since the wheels 41 to 44 are guided in the y direction by the rail 40, the carriage 20 advances in the y direction along the rail 40. When the cart drive motor is energized in reverse, the cart 20 moves backward (or reverse).

  The cart 20 is equipped with a sensor z drive mechanism 21 (FIG. 2), and a sensor x drive mechanism 23 is supported by a z arm 22 that is vertically driven by the mechanism 21. A manual x position adjusting mechanism 25 is supported by an x arm 24 that the mechanism 23 drives right and left, and a manual z position adjusting mechanism 26 is supported by the mechanism 25. The mechanism 26 supports the sensor support arm 27. The x, z movement detector 2 (FIGS. 2 and 3) is fixed to the sensor support arm 27. This x, z movement detector 2 holds the plunger movably within a small range in the x, z directions and is driven downward by a spring force, and a contact 1 is fixed to the lower end of the plunger. . During welding, as shown in FIGS. 7A to 7D, the lower end of the contact 1 enters the groove Ow and slightly rises on the groove surface.

  Inside the x and z movement detector 2, there are four pressure sensitive switches for detecting the movement of the plunger in the upper left direction, upper right direction, lower left direction and lower right direction, respectively. The x and z movement detectors 2 output the detection signals A to D.

  The x, z movement detector 2 holds the plunger movably within a small range in the x, z directions, the lower end of the contact 1 is supported by the groove surface, and the plunger is slightly pushed into the detector 2. However, when the external force applied from the left and right direction (the left side surface and the right side surface of the groove) is balanced, the posture of the contact 1 with respect to the x, z movement detector 2 is the reference posture ((a) to (a) in FIG. 7). (D)), the detection signal A of the first pressure-sensitive switch becomes a low level L (movement non-detection) when the plunger (contact 1 fixed to the plunger) deviates 0.5 mm or more upward or leftward from the reference posture. ) To high level H (upper left movement detection). Similarly, the detection signal of the second pressure-sensitive switch is switched from L (non-detection of movement) to H (detection of upper-right movement) when the contact 1 is shifted 0.5 mm or more upward or rightward from the reference posture, 3 The detection signal of the pressure-sensitive switch is switched from L (non-movement detection) to H (down-left movement detection) when the contact 1 deviates 0.5 mm or more in the downward or left direction from the reference posture. When it deviates 0.5 mm or more in the downward or rightward direction from the reference posture, it switches from L (movement non-detection) to H (down-right movement detection). The relationship between the movement of the contact 1 and changes in the detection signals A to D is shown in Table 1 below.

  In FIG. 4, in response to a change of the contact 1 from the reference posture, that is, a change in the detection signals A to D (changes in the x and z positions of the contact 1), x and z are returned to return the contact 1 to the reference posture. 3 shows a sensor scanning control circuit for energizing the electric motors Mxs and Mzs of the drive mechanisms 23 and 21. FIG. The detection signals A to D output from the x, z movement detector 2 are converted by the decoder 3 into eight types of signals a to h shown in Table 2 below.

  In the output signals a to h of the decoder 3, a to d are signals (A to D) which are decomposed (decoded) in four directions of up, left, right and bottom, and e to h are the original signals A, respectively. ~ D itself.

  Signals b, e, and g indicating the left shift of the contact 1 (groove Ow) are left-driven by the OR gate 4x of the sensor x target value generation circuit Ctxp constituting the sensor x scanning control circuit (Ctxp, 10x, 11x). The instruction signal Sxdown is assembled and applied to the Down instruction end of the counter 8x and also applied to the AND gate 7x through the OR gate 6x. Signals c, f, and h indicating the right shift of the contact 1 are assembled into the right drive instruction signal Sxup by the OR gate 5x, applied to the Up instruction end of the counter 8x, and applied to the AND gate 7x through the OR gate 6x. Is done. The left drive instruction signal Sxdown and the right drive instruction signal Sxup are also supplied to the torch copying control circuit (FIG. 5).

  A target position update timing pulse Poc is applied to the AND gate 7x. The initial value 128 is loaded as count data into the counter 8x of the sensor x target value generation circuit Ctxp when sensor scanning is started. The counter 8x counts down the pulse Poc while the left drive instruction signal Sxdown is H. That is, when one pulse of Poc arrives when Sxdown is H, the count data is updated to data representing a smaller numerical value. That is, the count data is decremented by one. The counter 8x also counts up the pulse Poc while the right drive instruction signal Sxup is H. That is, when one pulse of Poc arrives when Sxup is H, the count data is updated to data representing a larger numerical value. That is, the count data is incremented by one.

  The count data of the counter 8x is converted into an analog signal (signal voltage) by the D / A converter 9x and is given as a target position signal to the feedback circuit 10x. The rotation shaft of the potentiometer Pxs is mechanically coupled to the rotation shaft of the x drive electric motor Mxs of the sensor x drive mechanism 23. The potentiometer Pxs generates, as a feedback signal, a voltage representing an x position corresponding to the driving range 0 to 255 in the x direction of the x, z movement detector 2 to be driven by each step, and provides the feedback control circuit 10x with the voltage. The feedback control circuit 10x generates an error signal representing the deviation of the feedback signal (Pxs output) from the target position signal (9x output) and supplies it to the motor driver 11x. The motor driver 11x rotates and urges the x drive electric motor Mxs of the sensor x drive mechanism 23 in a direction in which the deviation becomes zero, and stops the urging of the electric motor Mxs when the deviation becomes zero. As a result, the contact 1 held by the x, z movement detector 2 is maintained at the center position in the x direction of the groove Ow.

  The sensor z drive mechanism 21 also has a potentiometer Pzs connected to the z drive electric motor Mzs, and the contact 1 held by the x, z movement detector 2 is opened by the sensor z scanning control circuit (Ctzp, 10z, 11z). The copying position (reference posture) is maintained in contact with both of the tips Ow with equal pressure. The configuration and function of the sensor z scanning control circuit are the same as those of the sensor x scanning control circuit described above, and the description of the sensor x scanning control circuit described above is read as “lower” and the right as “up”.

  1 to 3 will be referred to again. The carriage 20 has a leading torch sill mechanism 30L and a trailing torch sill mechanism 30T (FIGS. 1 and 2), and a leading torch 32L and a trailing torch 32T are supported by each.

  FIG. 5 shows a torch drive circuit. The preceding torch drive circuit is obtained by adding an adjustment value generating circuit SaL that gives a preceding torch target position adjustment value for preceding torch copying control to the preceding torch drive circuit (10L to 15L, AdL). Similarly, the trailing torch drive circuit is obtained by adding an adjustment value generating circuit SaT that provides a trailing torch target position adjustment value for trailing torch copying control to the trailing torch drive circuit (10T to 15T, AdT). It is. The configuration and function of the succeeding torch sill drive circuit (10T to 15T, AdT) are the same as those of the preceding torch sill drive circuit (10L to 15L, AdL). , AdL), and a detailed description of the trailing torch drive circuit (10T to 15T, AdT) is omitted.

FIG. 6 shows waveforms of various signals generated by the preceding torch drive circuit (10L to 15L, AdL).
Referring to FIG. 5 again, the pulse generator 12L of the target value generation circuit OtL, which is the main part of the preceding torch drive circuit (10L to 15L, AdL), has an oscillating frequency set by the user on the setting device Uda of the operation panel 35. An original pulse having a frequency twice that of F1 is generated, and the frequency divider 13L divides it into a constant level pulse (reference pulse) of the frequency F1 designated by the setting unit Uda and having a duty of 50%. In this embodiment, a pulse obtained by inverting the original pulse by the inverter 16L is given to the sensor scanning control circuit shown in FIG. 4 as the timing pulse Poc described above. Note that this pulse Poc is a pulse representing the arrival of the preceding torch 32 at the oscillating center position because it rises from L to H when the preceding torch 32L reaches the center position of the torch oscillation (swing) of the preceding torch 32L.

  The pulse of the oscillating frequency F1 is amplified by the variable gain amplifying circuit 14L with a gain proportional to the oscillating width (swinging width) W1 of the preceding torch set by the user in the setting device Uda, and then given to the time constant circuit 15L. In this embodiment, the settable oscillation width W1 is in the range of 0 to 191 steps, and the time constant circuit 15L generates a triangular wave that moves up and down at the frequency F1 between the oscillation width W1 and an analog adder (operational amplifier). ) Give to AdL. The center position of the oscillate can be adjusted between 0 and 32 steps by the user using the setting device Uda. An analog signal (voltage) Ma1 indicating the number of adjustment steps is also supplied to the adder AdL.

  At the OR gate 6L of the adjustment value generation circuit SaL and the Down instruction end of the counter 8L added to perform the torch copying control, a left drive instruction signal Sxdown generated by the target value generation circuit Ctxt (FIG. 4) for sensor copying is provided. The right drive instruction signal Sxup generated by the target value generation circuit Ctxp for sensor scanning is supplied to the Up instruction ends of the OR gate 6L and the counter 8L. These signals Sxdown and Sxup are also supplied to the AND gate 7L via the OR gate 6L. A target position update timing pulse Poc is applied to the AND gate 7L. The counter 8L is loaded with the initial value 32 as count data when torch scanning is started (simultaneously with the start of sensor scanning). The counter 8L counts down the pulse Poc while the left drive instruction signal Sxdown is H. The counter 8L also counts up the pulse Poc while the right drive instruction signal Sxup is H.

  The count data of the counter 8L is converted into an analog signal (adjustment signal by sensor scanning) by the D / A converter 9L and applied to the adder AdL. The adder AdL adds the triangular wave that moves up and down between the oscillating width W1 provided by the target value generation circuit OtL, the center position adjustment signal Ma1 provided by the setter Uda, and the adjustment signal based on the sensor scanning provided by the adjustment value generation circuit SaL. The feedback control circuit 10L is supplied as the x position target signal of the preceding torch.

  The rotary shaft of the potentiometer PxL is mechanically coupled to the rotary shaft of the x drive electric motor MxL of the preceding torch sill mechanism 30L. The potentiometer PxL generates a voltage representing an x movement amount corresponding to the driving range 0 to 255 in the x direction of the preceding torch 32L as a feedback signal, and supplies it to the feedback control circuit 10L. The feedback control circuit 10L generates an error signal representing the deviation of the feedback signal (PxL output) from the target position signal (AdL output) and supplies the error signal to the motor driver 11L. The motor driver 11L rotates and urges the x drive electric motor MxL of the torch sillating mechanism 30L in a direction in which the deviation is zero. Since the signal given by the target value generation circuit OtL is a triangular wave that moves up and down within the oscillation width W1, the leading torch 32L oscillates (oscillates) in the x direction in the range from the lower peak to the upper peak of the triangular wave. The leading torch 32L is at the left side inversion position at the lower peak of the triangular wave, and the right side inversion position at the upper peak.

  FIG. 6A shows an adder when the lower end of the contact 1 is equally in contact with two opposing surfaces of the groove Ow and the contact 1 is in the reference posture with respect to the x, z movement detector 2. An oscillation target position signal given by AdL to the feedback control circuit 10L is shown. Since the contact 1 is in the reference posture, that is, there is no unintentional opening, the oscillating target position signal is at a constant level.

  At a position where the groove is shifted to the right, as shown in FIG. 6B, the right drive instruction signal Sxup is switched from L to H, and during this H, the counter 8L counts up the timing pulse Poc. Therefore, the output voltage of the adjustment value generation circuit SaL (adjustment signal for scanning the sensor) rises, whereby the oscillating target position signal given to the feedback control circuit 10L by the adder AdL rises, and the oscillating center position is Shift to. The oscillation width does not change. At a location where the groove is shifted to the left, as shown in FIG. 6B, the left drive instruction signal Sxdown is switched from L to H, and during this H, the counter 8L counts down the timing pulse Poc. The output voltage of the adjustment value generation circuit SaL (adjustment signal for scanning the sensor) is lowered, whereby the oscillating target position signal given to the feedback control circuit 10L by the adder AdL is lowered, and the oscillating center position is shifted to the left. shift. This is groove tracking control of the welding torch based on the detection of the groove position deviation of the x, z movement detector 2, and the oscillation center position of the welding torch is automatically adjusted to the groove width center.

  FIGS. 7A to 7D show an enlarged view of the contact 1 mounted on the x, z movement detector 2 (the plunger). The contact 1 has two pins whose lower ends are opposed to the left and right groove surfaces in the groove Ow. These pins are arranged in the width direction x of the groove, and are in the same position in the direction y in which the groove extends. In (a) to (d) of FIG. 7, the contact 1 is in the “reference posture”, that is, the two pins hit the left groove surface and the right groove surface with the same pressure (pressing force) in the −z direction, In addition, the absolute value of the force received by the contact 1 from the left groove surface and the right groove surface is the same, and the directions are opposite, that is, balanced. When inserting the cut wire Fw as a filler into the groove, for example, the contact 1 having two pins has a wide groove width as shown in FIGS. 7 (a) to (d). However, since the lower end of the pin is unlikely to hit the cut wire Fw, the use of the contact 1 having two pins is highly adaptable to the wide and narrow groove width. If the contactor is a sphere or a plunger whose lower end is a hemispherical surface, this aspect is not intended to be excluded by the present invention. For example, as shown in FIGS. 7E to 7H, a spherical surface is formed on the cut wire Fw. It is easy to use, and when the cut wire Fw is filled, the adaptability to the wide and narrow groove width is low. Therefore, it is preferable to use the contact 1 having the two pins.

  The structure of the mechanical part of the second embodiment is the same as that of the first embodiment described above, but the structure of the torch drive circuit is slightly different. FIG. 8 shows a functional configuration of the torch drive circuit of the second embodiment. In the torch drive circuit of the first embodiment, the adder AdL, AdT generates the center position adjustment signal Ma1 and adjustment value generated by the setter Uda to the triangular wave that moves up and down between the oscillation width W1 provided by the target value generation circuit OtL. By adding an adjustment signal based on sensor scanning given by the circuit SaL, the center position of the oscillation of the welding torch is adjusted. However, in the second embodiment, instead of the adders AdL and AdT, subtracters (operational amplifiers using operational amplifiers) DeL and DeT are used, and the center position adjustment signal Ma1 provided by the setter Uda from the feedback signals of the potentiometers PxL and PxT and An adjustment signal based on sensor scanning given by the adjustment value generation circuit SaL is subtracted and a difference value signal is given to the feedback control circuits 10L and 10T. Also in this aspect, the oscillating operation of the welding torches 32L and 32T and the automatic groove profiling operation of the oscillating center position using the sensor profiling are the same as in the first embodiment.

  The structure of the mechanical part of the third embodiment is the same as that of the first embodiment, but the structure of the torch drive circuit is slightly different. FIG. 9 shows a functional configuration of the torch drive circuit of the third embodiment. In the third embodiment, the adders AdL and AdT add the center position adjustment signal Ma1 provided by the setter Uda and the adjustment signal generated by the adjustment value generating circuit SaL to the feedback signals of the potentiometers PxL and PxT, The sum signal is applied to the feedback control circuits 10L and 10T. In this case, in order to avoid that the moving direction of the center position of the torch bearing is opposite to the moving direction of the contact 1, the adjustment value generating circuits SaL and SaT send the right drive instruction signal Sxup to the Down of the counters 8L and 8T. The connection of the instruction signal is switched so that the left drive instruction signal Sxdown is applied to the instruction terminal at the instruction terminal. Also in this aspect, the oscillating operation of the welding torches 32L and 32T and the automatic groove profiling operation of the oscillating center position using the sensor profiling are the same as in the first embodiment.

  In any of the embodiments, the center position adjustment signal Ma1 given by the setter Uda and the adjustment signal based on the sensor scanning given by the adjustment value generation circuit SaL are given to the same adder or subtractor. The triangular wave moving up and down between the oscillation widths W1 may be added or subtracted, and the other may be added or subtracted from the potentiometer feedback signal.

  The structure of the mechanism portion of the fourth embodiment is the same as that of the first embodiment described above, but the electric motors Mxs and Mzs of the x and z drive mechanisms 23 and 21 are pulse motors, and these electric motors Mxs and Mzs. The motor drivers 11x and 11z of the sensor scanning control device that biases forward and reverse are pulse motor drivers.

  FIG. 10 shows a functional configuration of the sensor scanning control apparatus of the fourth embodiment. Since the feedback control (FIG. 4) of the first embodiment is not adopted in the fourth embodiment, the target value generation is not necessary. Therefore, in the fourth embodiment, the target value generation circuits Ctxp and Ctzp leave only the OR gates 4x, 5x and 4z, 5z that generate the left and right drive instruction signals Sxup, Sxdown and the upper and lower drive instruction signals Szup, Szdown. Omitted.

  When the right drive instruction signal Sxup (H level) is generated, the driver 11x step-drives the electric motor Mxs in the forward rotation direction at a predetermined period while the right drive instruction signal Sxup (H level) is generated, and step-drives the x and z movement detector 2 in the right direction. . In addition, when the left drive instruction signal Sxdown (H level) is generated, the driver 11x step-drives the electric motor Mxs in the reverse direction during a predetermined period, and step-drives the x and z movement detector 2 in the left direction. . As a result, the contact 1 held by the x, z movement detector 2 is maintained at the center position in the x direction of the groove Ow.

  When the upper drive instruction signal Szup (H level) is generated, the driver 11z energizes the electric motor Mzs in the normal rotation direction at a predetermined period and stepwise drives the x and z movement detector 2 in the predetermined period. . In addition, when the lower drive instruction signal Szdown (H level) is generated, the eleven drivers step-energize the electric motor Mzs in the reverse rotation direction at a predetermined period and step drive the x and z movement detectors 2 downward. To do. Thereby, the contact 1 held by the x, z movement detector 2 is maintained at a predetermined z position with respect to the groove Ow.

  Other configurations and functions of the fourth embodiment are the same as those of the first embodiment.

It is a top view of the 1st example of the present invention. It is a left view of 1st Example. It is a front view of 1st Example. FIG. 3 is a block diagram showing a configuration of a sensor scanning control device that drives drive electric motors Mxs and Mzs in the sensor x drive mechanism 23 and the sensor z drive mechanism 21 shown in FIG. 2. FIG. 3 is a block diagram showing a torch drive circuit that drives drive motors MxL and MxT in the leading torch sill mechanism 30L and the trailing torch sill mechanism 30T shown in FIG. (A) is a time chart schematically showing signals generated by the target value generation circuit OtL and the adder AdL shown in FIG. 5 when there is no opening, and (b) is an addition when there is unopening. It is a time chart which shows typically the signal which device AdL generates. (A)-(d) is an enlarged front view which shows the position with respect to groove | channel Ow of the contactor 1 shown in FIG. 3, (e)-(h) is this contactor when the spherical contactor 1a is used. It is an enlarged front view which shows the position with respect to 1 groove | channel Ow. It is a block diagram which shows the torch drive circuit of 2nd Example of this invention. It is a block diagram which shows the torch drive circuit of 3rd Example of this invention. It is a block diagram which shows the sensor copying control apparatus of 4th Example of this invention.

Explanation of symbols

1: contact 2: x, z movement detector 20: carriage 21: sensor z drive mechanism 22: z arm 23: sensor x drive mechanism 24: x arm 25: manual x position adjustment mechanism 26: manual z position adjustment mechanism 27 : Sensor support arms 30L, 30T: Torch sill mechanism 32L, 32T: Welding torch 33L, 33T: Manual z position adjustment mechanism 34L, 34T: Torch manual z position adjustment knob 35: Control panel 40: Rails 41-44: Wheels Mxs, Mzs: Sensor drive electric motors Pxs, Pzs: Potentiometers for sensor position feedback MxL, MzT: Torch drive electric motors PxL, PzT: Potentiometers for torch position feedback

Claims (7)

A carriage that travels in a direction y in which a groove between two materials to be welded or a welding region that is a corner formed by the two materials extends;
A torch mounted on the carriage for welding the welding region;
A torch drive mechanism for supporting the torch on the carriage and driving in the x direction crossing in the y direction;
The contact mounted on the carriage, located upstream of the torch with respect to the carriage movement direction during welding, and capable of simultaneously contacting both of the two welding objects in the welding region at the same position in the carriage movement direction. X, z movement detection separated from the torch and the torch drive mechanism for detecting a child and its movement in the x direction and the movement in the z direction crossing both the x and y directions. A contact sensor comprising:
A sensor drive mechanism that is separate from the torch drive mechanism and supports the x and z movement detectors and drives them in the x and z directions;
An x, z drive instruction signal for instructing driving in the same direction as the movement direction detected based on the x, z movement detection signal of the x, z movement detector is generated, and the x, z through the sensor driving mechanism is generated. sensor scanning control means for driving the z movement detector; and
A torch scanning control means for shifting the x-direction position of the torch via the torch drive mechanism separately from the sensor scanning control means in response to the x drive instruction signal generated by the sensor scanning control means;
A copying welding apparatus comprising:
The sensor drive mechanism increases or decreases by an x drive electric motor, a z drive electric motor for driving the x and z movement detectors forward and backward in the x and z directions, respectively, and forward and reverse of each electric motor. Each rotation amount detecting means for generating a rotation amount signal representing the rotation amount;
The sensor scanning control means generates an x, z target position signal and drives the x, z movement detector in the same direction while the x, z movement detector detects x, z movement. Means for updating the level of the x, z target position signal in steps, and feedback control means for driving each electric motor in a direction in which the rotation amount signal generated by each rotation amount detection means matches each target position signal, including;
The copying welding apparatus according to claim 1. The sensor driving mechanism includes an x driving electric motor and a z driving electric motor for driving the x, z movement detector in the x, z directions;
The sensor scanning control means includes a motor driver that step-drives the x, z drive electric motor in response to an x, z drive instruction signal generated by the sensor scanning control means;
The copying welding apparatus according to claim 1.   The torch drive mechanism is a swing mechanism that repeatedly reciprocates the torch in the x direction, and the torch copying control means shifts the center position of the reciprocating drive in response to the x drive instruction signal. The copying welding apparatus according to any one of the above. The torch drive mechanism includes an electric motor for reciprocatingly driving the torch in the x direction, and a rotation amount detection means for generating a rotation amount signal representing a rotation amount that increases and decreases by forward and reverse rotation of the electric motor;
The torch copying control means is a means for generating a target position signal for defining a movement trajectory of the reciprocating movement of the torch in the x direction, and the rotation amount signal generated by the rotation amount detection means is in a direction that matches the target position signal. In order to shift the center position of the reciprocating movement of the torch in the same direction as the moving direction of the contact in response to the x drive instruction signal generated by the feedback control means for driving the electric motor and the sensor scanning control means. Adjusting means for adding the adjustment to the target position signal or the rotation amount signal;
The profiling welding apparatus according to claim 4.   The adjustment unit updates an adjustment value to be added to the target position signal or the rotation amount signal stepwise at a predetermined period while the x drive instruction signal generated by the sensor scanning control unit is continued. 5. The copying welding apparatus according to 5. The profiling welding apparatus according to any one of claims 1 to 6, wherein the contact has two pins arranged in the x direction, each having a tip facing each of the two materials to be welded in the welding region. .

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