JPH079142A - Welding robot - Google Patents

Abstract

PURPOSE:To provide a welding robot which can shorten the time required for taking the positional information of a welding base material required for calculating the positional information of welding line of the welding base material. CONSTITUTION:The electrostatic capacity between a welding torch 1 and a welding base material 5 is detected with an electrostatic capacity detecting sensor 7, and the moving velocity of the welding torch 1 is made in high speed until a prescribed static capacity is detected in the time to control relative positions of the welding torch l and the welding base material 5 based on the information. In such a way, the sensing velocity until the welding torch 1 is made in contact with the welding base material 5 is made in high speed, and the time to need for taking the positional information of the welding base material 5 required for calculating the positional information of welding line of the welding base material 5 can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding robot for detecting a welding line position of a welding base material and performing welding.

[0002]

2. Description of the Related Art Conventionally, an automatic welding apparatus for contacting a welding torch electrode with a welding base metal to detect the position of the welding line of the welding base metal is disclosed, for example, in Japanese Patent Application Laid-Open No. 55-156673. The composition is known.

The structure will be described below with reference to FIG. In the figure, 21 is a welding torch, 22 is a welding base metal,
23 is an energization state detection device for detecting the energization state between the welding torch 21 and the welding base material 22, 24 is a control device, 25 is a storage device, 26 is a computing device, 27 is a robot, 28 is a welding / sensor power supply, Reference numeral 29 is a voltage selection device that selects a welding voltage and a sensor voltage. The voltage selection device 29 applies a preset sensor voltage to the welding torch 21 in response to a sensor command from the control device 24. At the same time, the energization state detection device 23 outputs the energization state between the electrode of the welding torch 21 and the welding base material 22 to the control device 24. The control device 24 controls the relative positions of the welding torch 21 and the welding base metal 22 according to a program given in advance, and also controls the welding torch 21.
The signal of the energized state between the electrode and the welding base material 22 is observed.
Then, the control device 24 detects the position of the electrode of the welding torch 21 at the time of energization by the energization state signal of the energization state detection device 23 due to the discharge phenomenon or contact between the electrode of the welding torch 21 and the welding base metal 22 and the welding base metal. The position of 22 is detected, the position is stored in the storage device 25, and the position of the welding line of the welding base material 22 is calculated by the calculation device 26.

[0004]

In the automatic welding apparatus having such a conventional structure, a sensor voltage is applied to the welding torch 21, and a discharge phenomenon or contact occurs between the electrode of the welding torch 21 and the welding base metal 22. Since the position of the welding base metal 22 is detected from the position of the welding torch 21 at the time of detecting the energization state by detecting the energization state signal of the energization state detection device 23, the relative position between the welding torch 21 and the welding base metal 22 is detected. There is a problem in that the welding torch 21 may collide with the welding base material 22 when performing various position controls.

In order to avoid this problem, the moving speed of the welding torch 21 should be limited to a speed at which the welding torch 21 does not collide with the welding base metal 22, but on the other hand, the welding line position information of the welding base metal 22 should be taken in. There was a problem that the required time would be long.

Further, in Japanese Laid-Open Patent Publication No. 2-152780, after the proximity sensor senses a work object, the moving speed of the work hand is gradually reduced based on a set deceleration pattern, so that the proximity sensor is activated. When the work hand reaches the position where the work object is located, the work object is sufficiently decelerated to a speed at which the capture work can be started while the work object is brought close to the work object with a small decrease in the moving speed after the operation. The guide device of the working machine is shown so as to be in the open state. However, this configuration does not have the function of calculating the welding line position information of the welding base metal necessary for the welding robot, that is, the function of moving the work hand on the line after approaching the object. there were.

The present invention solves the above problems and provides a welding robot capable of shortening the time required to fetch the position information of the welding base metal necessary for calculating the welding line position information of the welding base metal. Is intended.

[0008]

In order to achieve the above object, the present invention provides a welding torch, a welding power source device connected to the welding torch via a power source switching device, an electrode of the welding torch and welding. An energization state detection device for detecting an energization state between base materials, a capacitance detection sensor for detecting an electrostatic capacitance between the welding torch and the welding base material, the energization state detection device and the capacitance detection sensor The connected sensor power supply device, the power supply switching device that switches between the welding power supply device and the sensor power supply device, the welding torch and the information based on information from the capacitance detection sensor and the energization state detection device. A position control device that controls the relative position of the welding base metal, a speed control device that controls the moving speed of the welding torch during position control based on the information of the capacitance sensor, and the energized state A configuration including a storage device that captures the position information of the welding torch at the time of detecting the energization by the output device, and a computing device that computes the welding line position information in the welding base metal from the position information captured in the storage device Is.

[0009]

In the above structure, when the relative position of the welding torch and the welding base metal is controlled by the information of the electrostatic capacity detection sensor, the moving speed of the welding torch is increased until a predetermined electrostatic capacity is detected. By doing so, the sensing speed until the welding torch comes into contact with the welding base metal is increased, and the time required to capture the position information of the welding base metal necessary to calculate the welding line position information of the welding base metal is increased. Shortened.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In the figure, 1 is a welding torch, 2 is a welding power source device, which is connected to a welding torch 1 through a power source switching device 3. 4 is the electrode of the welding torch 1 and the welding base material 5
An energization state detecting device for detecting an energization state between the welding torch 1 and the position control device 6 via a power source switching device 3. Reference numeral 7 is a capacitance detection sensor that detects the capacitance between the electrode of the welding torch 1 and the welding base material 5, and is connected to the welding torch 1 and the position control device via the power supply switching device 3. Reference numeral 8 is a power source for a sensor which is a power source for the energization state detecting device 4 and the electrostatic capacity detection sensor 7, and 3 is a power source switching device for switching the welding power source device 2 and the sensor power source device.
It is connected to the welding torch 1 and the position control device 6. 6 is a position control device that controls the relative positions of the welding torch 1 and the welding base metal 5 based on information from the capacitance detection sensor 7 and the energization state detection device 4, and 9 is position based on information from the energization state detection device 4. A speed control device that controls the moving speed of the welding torch 1 during control, and is included in the position control device 6. 1
Reference numeral 0 denotes a storage device which takes in position information of the welding torch 1 when the energization state detection device 4 detects energization, and is included in the position control device 6. Reference numeral 11 denotes a calculation device that calculates the welding line position information on the welding base material 5 from the position information stored in the storage device 10, and is included in the position control device 6. 12 is a welding robot.

In the above structure, the position control device 6 controls the relative positions of the welding torch 1 and the welding base material 5 according to a program taught in advance. That is, according to the taught program, the position control device 6 controls the position of the welding torch electrode 13 from the position P1 along the direction A as shown in FIG. The speed is controlled by the speed control device 9 based on the electrostatic capacitance signal detected at. Then, the welding torch electrode 13 comes into contact with the welding base material 5 at the position P2, and the energization state detection device 4 detects the energization state. The position of the welding torch electrode 13 is taken into the storage device 10 by the signal, and the arithmetic unit 11 calculates the welding line position information of the welding base metal 5 based on the position information regarding the welding base metal 5 taken into the storage device 10. To do.

Next, speed control when the position of the welding torch 1 is controlled by the speed control device 9 will be described.

FIG. 3 shows an output signal of the electrostatic capacity detection sensor 7 connected between the welding torch electrode 13 and the welding base material 5.
As is well known, the electrostatic capacity is inversely proportional to the distance between the two electrodes, and in this embodiment, the two electrodes are formed by the welding torch electrode 13 and the welding base material 5. And
The position control device 6 detects the relative distance between the welding torch electrode 13 and the welding base metal 5 based on the signal from the electrostatic capacitance detection sensor 7 that detects the electrostatic capacitance between the two electrodes, and the welding torch 1 is detected.
Is moved in the direction A from the position P1. At that time, the position P1
Then, the speed control device 9 sets the moving speed of the welding torch 1 to a high speed. Further, with respect to the signal of the electrostatic capacity detection sensor 7, a threshold value C0 is set in advance in the signal level of the electrostatic capacity detection sensor 7 in a range in which the energized state is not detected by the energized state detection device 4, and At a position P3 where the level exceeds the threshold value C0, the moving speed of the welding torch 1 is set to a low speed by the speed control device 9.

Since the electrostatic capacitance between the welding torch 1 and the welding base material 5 is detected, the welding torch 1
The distance between the welding base material 5 and the welding base material 5 can be detected in a continuous amount, and the accuracy can be improved. Further, there is an advantage that it is not necessary to provide a special sensor such as a proximity sensor.

As described above, according to the welding robot of the embodiment of the present invention, the position control device 6 includes the welding torch 1 and the welding base material 5.
Since the welding torch 1 is moved so as to avoid the collision of the welding torch 1 and the position thereof is controlled, the moving speed of the welding torch 1 from the position P1 to the position P3 is increased, and the welding line position information of the welding base metal 5 is calculated. There is an effect that it is possible to shorten the detection time for fetching the necessary position information of the welding base material 5.

[0017]

As is apparent from the above description of the embodiments, according to the present invention, the capacitance between the welding torch electrode and the welding base metal is detected by the capacitance detection sensor, and the detected detection is performed. Since the position control device controls the moving speed of the welding torch by the capacity, the welding torch can be moved at high speed and low speed so as to avoid the collision between the welding torch and the welding base metal, and the high speed movement allows the welding mother to move. It is possible to shorten the detection time for fetching the position information of the welding base metal necessary for calculating the welding line position information of the material.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a welding robot according to an embodiment of the present invention.

FIG. 2 is an enlarged side view of the main part.

FIG. 3 is an output characteristic diagram of the same capacitance detection sensor.

FIG. 4 is a configuration diagram of a conventional welding robot.

[Description of symbols] 1 welding torch 2 welding power supply device 3 power supply switching device 4 energization state detection device 5 welding base material 6 position control device 7 electrostatic capacitance detection sensor 8 sensor power supply 9 speed control device 10 storage device 11 computing device

Claims (2)

[Claims] 1. A welding torch, a welding power source device connected to the welding torch via a power source switching device, and an energization state detecting device for detecting an energization state between an electrode of the welding torch and a welding base metal, A capacitance detection sensor for detecting a capacitance between the welding torch and the welding base metal, a power supply device for a sensor connected to the conduction state detection device and the capacitance detection sensor, and a welding power supply device. A power source switching device that switches between the sensor power source device and a position control device that controls the relative positions of the welding torch and the welding base metal based on information from the capacitance detection sensor and the energization state detection device. A speed control device that controls the moving speed of the welding torch during position control based on the information of the capacitance sensor, and a position of the welding torch when the energization is detected by the energization state detection device. A welding robot, comprising: a storage device for taking in the placement information; and a computing device for computing the welding line position information in the welding base material from the position information fetched in the storage device. 2. A threshold value is set for the electrostatic capacity detected by the electrostatic capacity detection sensor, and the moving speed of the welding torch is made high until the electrostatic capacity exceeds the threshold value, and the threshold value is set. 2. The welding robot according to claim 1, wherein a moving speed of the welding torch is controlled by a speed control device so as to reduce the speed when the welding speed exceeds the limit.