JPS6320633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a swinging device that is installed in an automatic/semi-automatic welding device and swings the torch while holding the torch. It is configured to stop at a specific position inside.

As welding automation has progressed in recent years, many devices for mechanically swinging a welding torch have been proposed and put into practical use in various types of welding, such as CO ₂ , MIG, and no-gas welding. In addition, these swing devices have a device that temporarily stops the torch during the swing cycle in order to obtain stable penetration that corresponds to the shape of the weld joint and to form a weld bead with a constant and beautiful external shape. Many of them are equipped with a mechanism or a device that allows the stop time to be freely adjusted.

By the way, in such a swinging device with a stop device, it is desired that the stop position of the torch is a constant position regardless of the swinging speed of the torch. In addition, it is generally desirable to set these stop positions at the center of the oscillation width, especially in vertical or downward uranami welding, to improve the formation of the back bead.
In addition, in order to obtain sufficient penetration, there is a strong demand for stopping at the center. That is, if the groove is not stopped at the center, the arc heat will not be concentrated in the deep part of the groove, resulting in poor penetration, and this tendency is particularly noticeable when a steel backing is used and the root gap is small.

On the other hand, stopping the torch at the center of the swing width may seem easy at first glance, but the inertia and swing speed of the drive motor and swing drive components are complicated, so the design is designed to stop the torch at the center. In reality, positional deviations often occur. Figure 1 is an explanatory diagram showing these stopping position deviations, and the line X ₁ (X ₂ , X ₃ )
and R ₁ (R ₂ , R ₃ ) with a constant width trajectory Y, and the center line C between X and R
is the set center stop position. Further, regarding the trajectory Y, it is assumed that the torch advances in the direction of the arrow. Ideally, in such a swinging device, if a stop operation is commanded as shown in Figure A, it will always be stopped on the center line C, regardless of whether it is reciprocating or not. For example, if the moving speed of the torch is low and the inertia is weak, the center line C will not reach the center line C and will stop at a point H in front of you, as shown in Figure B. On the other hand, when the moving speed is high, the inertia also increases and overrun occurs, resulting in a stopping position as shown in diagram C. That is, as described above, the welding in the center is not sufficient, resulting in poor welding.

Therefore, as a measure to prevent these positional deviations in conventional rocking devices, there is a method of using a low-inertia drive motor to minimize the positional deviation as much as possible. Methods of arranging the stop position detector at an optimum front position so as to minimize the deviation, and methods of making the set position of the stop position detector movable so that it can be adjusted have been used. However, the above-mentioned countermeasure only reduces positional deviation, but is not practical in view of the characteristics of the motor. This countermeasure is a commonly used method, and is recommended as an extremely convenient countermeasure because the swing speed is limited to a certain range in specialized welding machines for vertical or downward welding. For example, the number of oscillations for vertical welding is 10.
~20 times/min, the number of downward welding oscillations is 30 to 60 times/min.
Generally, the number of swings is 15 times/minute in the case of standing position, and considering the inertia in that case, take the above measures to prevent the center stop position from shifting. If you want to do this 10 times/minute,
Since there is little deviation in the installation position when 20 times/min is used, it can be put to practical use. Similarly, in the case of downward welding, it can be used in the range of 30 to 60 times/minute based on the number of oscillations of 45 times/minute, but strictly speaking, the central stop position is not determined. Satisfactory welding may not be possible when welding joints under severe welding conditions. Furthermore, the swing device of the welding equipment can be used from vertical to downward or horizontal position.
The range of oscillation times expands from 10 times/minute to 70 times/minute,
The above-mentioned measures are completely insufficient to obtain satisfactory center stopping characteristics over this entire range.

On the other hand, the above-mentioned countermeasure is extremely complicated, as it is necessary to change the set position of the stop position detector or adjust the operating position of the striker for operating the detector each time the swing speed is adjusted. Furthermore, the number of components for changing the setting position and adjusting the operating position increases, making the swinging device larger and making maintenance management difficult. Therefore, over the entire range of rocking speeds from 10 to 70 times/min, the center stop position does not shift, or at least stops reliably at the center within a range that does not cause any practical problems, and is easy to handle. The development of a rocking device is desired.

The present invention has been made in view of these circumstances, and it is an object of the present invention to provide a rocking device that satisfies all of the above. However, the present invention as described above consists of a position detector that detects the torch when it reaches the stop position, a function generator that starts generating a function signal upon receiving the signal from the detector, and a detector that detects the torch oscillation speed. Alternatively, the speed signal generator is configured to include a speed signal generator for setting and a comparator for comparing the signals of the function generator and the speed signal generator, and the output signal of the comparator is used as a stop signal.

The present invention will be described in detail below based on the drawings, but the drawings show specific configuration examples, and in keeping with the spirit of the above and below, other members with the same effect may be used or some designs may be modified. It can be implemented in the same way even if you change . Furthermore, the embodiments described in the claims do not limit the present invention. FIG. 2 is a structural block diagram of the rocking device of the present invention, and 7 shows the rocking device equipped with a torch. As the rocking device, a conventional rocking device or a rocking device that will be developed in the future can be used. The device used is one equipped with a single electric motor for driving. Reference numeral 6 indicates the motor, and a drive circuit indicated by 5 commands the motor to start and stop. 1 is a detector that detects the torch when it reaches a position near the central stop position, and uses a micro switch, various proximity switches, a photoelectric switch, a reed switch, etc. Further, the detector 1 is used by being attached to a moving member or a rotating member that can detect the torch position during the oscillation period. For example, it is preferable to attach it to the output shaft of a reducer that reduces the rotational speed of the drive motor 6. FIGS. 3 and 4 show an embodiment in which a position before stopping is detected using such a decelerator.
That is, 11 is the output shaft of the speed reducer, and the swinging device is driven by this output shaft 11. 12 is the output shaft 11
With a striker attached to the striker, a protrusion 13 is formed in a part of its periphery. On the other hand, a detector 15 is disposed on the outer periphery of the rotation locus of the striker 12, and the detector 15 emits a signal when the detection portion 16 and the protruding portion 13 of the striker 12 meet. However, at the time this signal is generated, the side portion 14 of the protrusion 13 is located at the detection portion 1.
It's time to reach 6. On the other hand, reference numeral 17 indicates the swing locus of the torch, and reference numeral 18 indicates the central stop position thereof. Third
In the figure, the striker 12 rotates in the direction of the arrow 20,
It is assumed that the swinging proceeds in the direction of arrow 21. Then, at a position 19 in front of the stop position 18, the side part 14 of the protruding part 13 of the striker 12 and the detector 16 match and output a detection signal, and after the operation described in detail later, the striker 12 protrudes as shown in FIG. Center of section 13 and detection section 1
It stops at the position that matches 6. Therefore, in these illustrated examples, 1/2 of the width W of the protrusion 13 of the striker
The front position is detected as the front position for stopping.

The signal that detects the front position in this way is the front second
The signal is sent to the function generator 2 shown in the figure, and upon receiving the signal, the function generator 2 starts generating a function and inputs the signal to the comparator 4. The other 3 is a swing speed signal generator, and the generator 3 is a signal generator proportional to the swing speed, such as a circuit that detects the voltage between the terminals of the drive motor, a tachogenerator attached to the motor, or a motor speed setting reference voltage generator. This signal is input to the comparator 4 using a device that can generate a signal (voltage). The signal from the comparator 4 is then sent to the drive circuit 5 of the motor 6, and commands are given to start and stop the motor.

On the other hand, the operation of the detection signal is performed as follows in this embodiment. That is, as the function of the function generator 2, an exponential curve voltage V _CR as shown in FIG. 5 is used. The exponential curve voltage V _CR asymptotically approaches the voltage V _{V 1} to V ₄ in response to the signal that detects the position 19 in front of the stop position 18 . That is, in the figure, V _V is a signal input from the swing speed signal generator 3 to the comparator 4, which is a voltage proportional to the swing speed V, and the voltage
V _V1 , V _V2 , and V _V3 indicate signals corresponding to the swing speeds v ₁ , v ₂ , and v ₃ . In the comparator 4, the exponential curve voltage V _CR and the voltage V _V are compared, and the exponential curve voltage
A stop signal is sent to the motor drive circuit 5 only when V _CR becomes smaller than the voltage V _V. The drive circuit 5 applies a brake to the motor 6 in response to this stop signal to stop the swinging device 7. Through these series of operations, the swing output can be stopped at the stop position. Furthermore, to explain these operations using Fig. 5, when the swing speed is v ₁ (maximum swing speed), 22
At point a, V _CR <V _V1 , and at t ₁ =0, a stop signal 22C is issued and the brake is applied. That is, the brake is applied at the same position 22a as the stop position 19, but since the swing speed _v1 is fast, the motor swings a distance _L1 and stops at the center stop position 18. When the swing speed is v ₂ , V _CR <V _V2 at point 23b, and a stop signal 23c is generated with a delay of t ₂ to apply the brakes. That is, the brake is applied only when it swings by a distance of v ₂ ×t ₂ from the position 19 in front of the stop position and reaches point 23a. After the brake is applied, v ₂ gradually decreases and the motor stops, but in the meantime it oscillates by a distance L ₂ and stops at the stop position 18. Similarly, when the swing speed is v ₃ , V _CR <V _V3 at point 24b, so a stop signal 24c is transmitted with a delay of v ₃ and the brake is applied.
That is, it swings by a distance of v ₃ × t ₃ from the position 19 in front of the stop position, and when it reaches point 24a, the brake is applied, and v ₃ gradually decreases, and after swinging by a distance L ₃ , it stops at the stop position 18. .

Since the swinging device of the present invention is constructed in this way, it is possible to always accurately stop the torch at the target stop position even when the swinging speeds are different, and the effects as summarized below can be obtained.

Since the rocking stop position is precisely constant, it is possible to achieve stable penetration in various types of welding, uniformity of the underwave bead, and beautiful bead appearance.

Welding conditions can be easily selected, reducing the burden on the operator, reducing fatigue, and improving efficiency.

The swinging device can be used for welding in vertical, downward, and horizontal positions, and unlike conventional swinging devices, dedicated swinging devices are not required for each position, and the investment for equipment can be reduced. Furthermore, since the configuration is simple, maintenance management is also easy.

The swinging device can be downsized and can be easily attached to any welding device. It can also be provided at low cost.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram illustrating the swinging of the torch and its stop position, Fig. 2 is a block diagram showing the configuration of the swing device of the present invention, and Figs. 3 and 4 are specific examples of stop position detection. FIG. 5 is an explanatory diagram showing the operation from front position detection to stopping. 1... Front position detector, 2... Function generator, 3
...Rolling speed signal generator, 4...Comparator, 5...
Motor drive circuit, 6... Motor, 7... Rocking device, 11... Output shaft, 12... Striker, 13
...protrusion, 14 ... side, 15 ... detector, 1
6...Detection unit, 17...Torch swing trajectory, 18...
...Front position, 19...Central stop position.

Claims (1)

[Scope of Claims] 1. A swing device that supports and swings a welding torch and stops the torch at a specific position during the swing cycle, and a detector that detects the torch when it reaches the stop position. , a function generator that starts generating a function signal in response to a signal from the detector, a speed signal generator that detects or sets the torch swing speed, and a comparison that compares the signals of the function generator and the speed signal generator. 1. A swinging device for a welding torch, characterized in that the output signal of the comparator is used as a stop signal to keep the torch stop position constant regardless of the swinging speed. 2. The welding torch oscillation device according to claim 1, wherein the function generator generates an exponential function signal. 3. In claim 1 or 2, the signal of the torch oscillation speed signal generator is any one of the voltage between the terminals of the oscillation drive motor of the oscillation device, the voltage of the tachogenerator, and the oscillation speed setting reference voltage. A swing device for a welding torch that uses one.