JPH09103880A - Method and device for arc welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve workability by measuring the rotational eccentricity of a member to be welded of an electronic tube without contacting, improving the quality of the member 11 to be welded and reducing the positioning operation incident to the measuring. SOLUTION: A member 11 to be welded having a weld zone 14 on the outer circumference is rotated around its axial center on a rotary stage 22. Measurement is done by a measuring means 31 without contacting on such displacement of the weld zone 14 in the radial direction that is due to the rotational eccentricity of the member 11 so rotated on the rotary stage. Welding is performed on the weld zone 14 of the member 11 by a welding means 32. The welding means 32 is moved in the radial direction against the rotational center of the rotary stage 22 by a moving means 23. The moving means 23 is controlled by a controller 34 based on the displacement measured by the measuring means 31, keeping the distance of the welding means 32 constant against the weld zone 14 of the member 11 to be welded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an arc welding method and apparatus for arc welding a member to be welded.

[0002]

2. Description of the Related Art Conventionally, for example, an X-ray image tube is an electron tube that includes an envelope serving as a vacuum vessel, an input substrate, an output substrate, a grid, and the like, and converts an X-ray image into a visible image.

[0003] This X-ray image tube is assembled by assembling the envelope and the grid by resistance welding or the like and then assembling the envelope in the order of the output substrate and the input substrate by arc welding such as TIG welding. Combine and assemble.

FIG. 4 shows the configuration of a conventional arc welding apparatus for arc welding an envelope and an output substrate. Rotating the vacuum vessel 1 combining the envelope and the output substrate with the rotary stage 2
The weight body 3 is mounted on the vacuum vessel 1 to increase the degree of adhesion between the envelope and the output substrate and also serves as one electrode for arc welding. The welding torch 4 is mounted on a moving mechanism 5 for moving the rotating torch 2 in the axial direction and in the radial direction with respect to the center of rotation, respectively. It is positioned and arranged at a predetermined distance position with respect to the portion 1a. Then, while rotating the vacuum vessel 1 about the axis thereof on the rotary stage 2, arc welding is performed between the welding electrode of the welding torch 4 and the welding portion 1a to perform arc welding on the welding portion 1a.

By the way, while the vacuum vessel 1 is rotated, the entire circumference of the welded portion 1a is arc-welded, but it is preferable that the positional relationship between the welded portion 1a and the welding electrode of the welding torch 4 is always constant. Condition. However, since the vacuum container 1 has a rotational eccentricity due to the assembly accuracy of the vacuum container 1 and an attachment error to the rotary stage 2, the position of the welding torch 4 is made to follow the radial displacement of the welded portion 1a due to the rotational eccentricity. There is a need.

Therefore, the weight 3 is arranged coaxially with the vacuum container 1 so that the displacement of the welded portion 1a due to the rotational eccentricity of the vacuum container 1 and the displacement of the weight 3 are equal, and the weight 3
The displacement of the outer peripheral portion of the weight body 3 is measured by the contact type measuring device 6 that comes into contact with the outer peripheral portion, and the measured displacement amount is converted into the moving amount of the moving mechanism 5 by the control unit 7, and the welding is performed by the moving mechanism 5. Follow the position of the torch 4.

[0007]

However, in the prior art, when measuring the displacement of the welded portion in the radial direction due to the rotational eccentricity of the vacuum container 1, the contact type measuring device 6 which comes into contact with the weight 3 is used. As a result of the abrasion, abrasion powder or the like is generated, and the abrasion powder or the like adheres to the vacuum container 1 and X
This may deteriorate the characteristics of the line image tube.

Moreover, every time the vacuum container 1 is replaced with respect to the rotary stage 2, the contact type measuring device 6 has to be brought into positioning contact with the weight 3 placed on the vacuum container 1, which is troublesome for positioning. However, there is a problem in that workability is poor.

Further, the welding electrode of the welding torch 4 comes into contact with the welded portion 1a due to the malfunction of the contact type measuring device 6 and the difference between the welding position by the welding torch 4 and the measuring position by the contact type measuring device 6. In some cases, there is a possibility that they will be separated.

When the welding electrode of the welding torch 4 comes into contact with the welded portion 1a, the welded electrode and the welded portion 1a are joined together, and the vacuum container 1,
Abnormalities such as breakage occur in the welding torch 4 and welding equipment. Further, if the welding electrode of the welding torch 4 is too far from the welded portion 1a, the welding arc becomes unstable and welding failure occurs.

Therefore, the present invention is to solve such a point, and to keep the distance of the welding means with respect to the welded portion constant and to deal with the case where the distance is deviated. And to provide a device.

[0012]

According to the arc welding method of the present invention, a step of rotating a welded member having a welded portion on its outer periphery and a displacement amount of the welded portion in the radial direction due to rotational eccentricity of the rotating welded member. And the step of measuring the non-contact, arc welding the welding portion of the rotating member to be welded,
According to the measured displacement amount, the welding means is moved in the radial direction to keep the distance to the welded portion constant.

An arc welding apparatus using this arc welding method includes a rotary stage for rotating a member to be welded having a welded portion on its outer circumference, and a welded portion in the radial direction due to rotational eccentricity of the member to be rotated rotated by the rotary stage. Measuring means for measuring the amount of displacement in a non-contact manner, welding means for arc welding the welded portion of the member to be welded, and moving means for moving this welding means in the radial direction with respect to the rotation center of the rotary stage,
The control means controls the moving means on the basis of the displacement amount measured by the measuring means, and keeps the distance of the welding means to the welding portion of the member to be welded constant.

By measuring the displacement of the welded portion in the radial direction due to the rotational eccentricity of the member to be welded without contact,
Keep the distance of the welding means to the weld constant. further,
When the member to be welded is mounted on the rotary stage, it is not necessary to position the measuring means, and only the welding means may be positioned with respect to the welded portion.

Further, the arc welding method of the present invention comprises the steps of outputting a constant welding current to the welding means to arc weld the welded portion of the member to be welded, and the step of detecting the welding voltage output to the welding means. And a step of stopping the output of the welding current to the welding means when the detected welding voltage is different from the welding voltage at the time of normal arc welding.

An arc welding apparatus using this arc welding method comprises a welding means for arc welding the welded part of a member to be welded, a welding power source part for outputting a constant welding current to the welding means, and a welding power source part Welding voltage detection unit that detects the welding voltage output and the welding current output from the welding power supply unit when the welding voltage detected by this welding voltage detection unit is different from the welding voltage during normal arc welding. And a control unit for stopping.

During welding, the welding voltage output from the welding power source is detected to monitor the welding condition.
For example, when the welding portion and the welding means are in contact with each other, the resistance value between the welding portion and the welding means is lowered and the welding voltage is also lowered. On the contrary, when the welding portion and the welding means are too far apart from each other, ,
The resistance value between the weld and the welding means increases, and the welding voltage also increases. Since the welding voltage is different from the welding voltage during normal arc welding, the welding current output from the welding power source is stopped.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of an arc welding method and apparatus of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, 11 is a vacuum container of an electron tube as a member to be welded. The electron tube is, for example, an X-ray image tube, which is provided with an envelope 12, an input substrate, an output substrate 13, a grid, etc. as a vacuum container 11 and converts an X-ray image into a visible image. In the figure, the envelope 12 and the output board 13 of the vacuum container 11 are shown.
13 Welding is performed.

As shown in FIG. 2, the output substrate 13 of the envelope 12
A flange-shaped ring 12a is formed at the upper end where the ring is mounted, and a flange-shaped ring 13a is formed on the output substrate 13 to be joined to the ring 12a. The outer peripheral portion where these rings 12a, 13a are joined is welded. The unit 14 is provided.

FIG. 1 shows a block diagram of a manufacturing apparatus for welding the vacuum container 11. Reference numeral 21 is a base, on which a rotary stage 22 and a moving stage 23 as a moving means are installed. There is.

The rotary stage 22 positions and holds the vacuum container 11 and rotates it about the axis of the vacuum container 11 by driving a motor (not shown).
An encoder (not shown) for detecting the rotational position of 11 is provided.

On the vacuum container 11 which is positioned and held on the rotary stage 22, a weight body 24 is mounted which serves as one electrode for arc welding in order to enhance the degree of adhesion between the envelope 12 and the output substrate 13. The weight 24 is made of, for example, copper, and as shown in FIG. 2, a fitting recess 25 for fitting with the output substrate 13 of the vacuum container 11 is formed on the lower surface, an electrode 26 is connected to the upper surface, and an upper peripheral surface. A cylindrical body 27 made of white acrylic is fitted and fixed to. The surface of the cylinder 27 is formed smooth.

The moving stage 23 is moved in the radial direction with respect to the center of rotation of the rotating stage 22, as shown in FIG.
Along with the axis stage 28, there is also provided a Z-axis stage 29 which is vertically movable with respect to the X-axis stage 28.

A horizontal support base 30 is attached to the Z-axis stage 29, and a laser measuring device 31 as a measuring means and a welding torch 32 as a welding means are mounted on the support base 30. The laser measuring device 31 irradiates the laser beam to the cylinder 27 of the weight 24, receives the laser beam reflected from the cylinder 27, and measures the relative distance between the laser beam and the cylinder 27. The welding torch 32 is for arc welding such as TIG welding, and has a welding electrode 33 for welding the welding portion 14 at the tip.

A control unit 34 controls the entire apparatus and includes a storage unit 35 capable of writing and reading various data. Then, the control unit 34
The controller controls the rotary stage 22, the X-axis stage 28, and the Z-axis stage 29, which are connected via control cables 36, 37, and 38, respectively. The storage unit 35 receives angle data obtained from the encoder of the rotary stage 22 via the communication cable 39 and measurement data obtained from the laser measuring device 31 via the communication cable 40. Note that the control unit 34 and the storage unit 35 can communicate with each other.

Next, the operation of the first embodiment will be described.

First, a setting operation for welding the vacuum container 11 is performed. A vacuum container (11) in which an envelope (12) and an output substrate (13) are superposed is positioned and mounted on a rotary stage (22), and a weight body (24) is placed on the vacuum container (11). The weight 24
Is positioned coaxially with the vacuum vessel 11 by fitting the fitting recess 25 into the output substrate 13 of the vacuum vessel 11.

The welding electrode 33 at the tip of the welding torch 32 is moved by the moving stage 23 to the welding portion 14 of the vacuum vessel 11 at a predetermined distance position where good welding can be performed and positioned.

After that, the welding operation by the control unit 34 is automatically performed by operating a start switch of a control panel (not shown) or the like.

In the welding operation under the control of the control unit 34, first, the rotational eccentricity of the vacuum container 11 is measured. This is because the vacuum container 11 has a rotational eccentricity due to the assembling accuracy of the vacuum container 11, an attachment error to the rotary stage 22, etc. Therefore, the displacement amount of the welded portion 14 in the radial direction due to the rotational eccentricity is measured.

While rotating the vacuum container 11 by the rotating stage 22 in the direction opposite to the rotating direction at the time of welding, the laser measuring instrument
The cylindrical body 27 of the weight body 24 is irradiated with a laser beam from 31 and the reflected light is received, and the measured value is measured by the rotary stage 22.
Storage unit corresponding to the rotation angle obtained from the encoder
Remember in 35. As a result, the radial displacement amount due to the rotational eccentricity of the vacuum container 11 is obtained for the entire circumference of the welded portion 14 of the vacuum container 11 positioned coaxially with the weight body 24.
The rotation stage 22 is stopped after one rotation.

Subsequently, the welding portion 14 of the vacuum container 11 is welded. At the welding start point, the welding torch 32 is placed at a predetermined distance position where good welding can be performed on the welded portion 14.
Is located.

Welding electrode 33 of welding torch 32 and electrode of weight 24
A welding current is applied between the welding torch 32 and the welding electrode 33 of the welding torch 32.
Arc welding is performed between the welding part 14 of the vacuum vessel 11 and the welding part 14 of the vacuum container 11 to start welding of the welding part 14.

Simultaneously with the start of welding, the control unit 34 controls the rotation based on the data stored in the storage unit 35, that is, the relationship between the rotation angle of the vacuum container 11 and the radial displacement due to the rotation eccentricity. A vacuum container that rotates the stage 22 in a predetermined rotation direction during welding and moves the X-axis stage 28 according to the rotation angle of the rotation stage 22 to rotate the stage.
Welding portion 14 is welded so that welding torch 32 always maintains a constant distance with respect to welding portion 14 of 11. Rotating stage 22
After one rotation, the rotation of the rotary stage 22 is stopped and the welding is stopped.

As described above, since the displacement amount of the welded portion 14 in the radial direction due to the rotational eccentricity of the vacuum container 11 is measured by the laser measuring device 31 in a non-contact manner, the weight body and the measuring device are separated from each other as in the conventional case. Since there is no contact and no abrasion powder is generated due to abrasion, the quality of the vacuum container 11 can be improved.

Further, when the vacuum container 11 is mounted on the rotary stage 22, it is not necessary to position the laser measuring device 31, and only the welding torch 32 needs to be positioned with respect to the welding portion 14, which improves workability.

Moreover, since the amount of displacement of the welded portion 14 in the radial direction due to the rotational eccentricity of the vacuum container 11 is measured and stored and then the arc welding is actually performed based on the stored data, the arc welding Laser measuring instrument that is not affected by electrical noise, strong arc discharge light generated during welding, etc.
Accurately measure by 31.

If arc discharge light or the like during welding does not interfere with the laser measuring device 31, measurement and welding are performed at the same time, and the position of the welding torch 32 is directly followed according to the measurement result. Good.

Further, since the rotating direction of the rotary stage 22 at the time of measurement is opposite to the rotating direction at the time of welding, it is possible to prevent the entanglement of the welding ground cable or the like.

Next, a second embodiment will be described with reference to FIG.

The control unit 34 includes a rotary motor 41 and a welding power source unit.
42, a welding voltage detector 43, and a copying mechanism 44 are connected.

The rotary motor 41 operates according to a control signal output from the control section 34 to rotate the rotary stage 22.

The welding power source unit 42 has a power source control unit 45 which operates according to a control signal output from the control unit 34, and the welding power source unit 45 outputs welding current preset by a volume or the like. The current output unit 46 is controlled. The welding current output section 46 is exposed to the outside of the welding power source section 42 (-).
The welding current is output between the (+) output terminals and
The high frequency output is given to the output terminal side of (-) through the transformer Tr, and the current detection section 47 for detecting the welding current is connected to the output terminal side of (+). The current detection signal is input. Then, the welding current output section 46
Controls the welding voltage output by inputting the welding current detection signal from the current detection unit 47 and keeping the welding current constant (setting value).

A cable 48 connected to the (-) output terminal side of the welding power source 42 is connected to the welding electrode of the welding torch 32, and a cable 49 connected to the (+) output terminal side is a weight body.
Connected to 24.

The welding voltage detection unit 43 has a pair of voltage dividing resistors R1 and R2 connected between the welding current output units of the welding current output unit 46, and the welding current output unit 46 is connected by these voltage dividing resistors R1 and R2. The control unit 34 reads the welding voltage by dividing the welding voltage output from the controller. The voltage dividing resistor R1 is set to a higher resistance value than the voltage dividing resistor R2.

The copying mechanism 44 includes a laser measuring instrument 31 and a welding torch 32, measures the distance x between the weight measuring instrument 31 and the weight 24, and outputs the distance data to the control section 34 and the control section. A control signal is input from 34, and the welding torch 32 is fixed to the welded portion 14 at a constant interval, for example, 1.0 mm to
The welding torch 32 is moved so as to keep about 1.5 mm. Although not shown, a moving means 23 for moving the welding torch 32 is provided. Further, when the distance data is input from the laser measuring device 31, the control unit 34 calculates the distance between the welding portion 14 and the welding torch 32, and at the same time, the welding portion 14
A control signal is output to the copying mechanism 44 so that the distance between the welding torch 32 and the welding torch 32 becomes constant.

Next, the operation of the second embodiment will be described.

First, a setting operation for welding the vacuum container 11 is performed. A vacuum container (11) in which an envelope (12) and an output substrate (13) are superposed is positioned and mounted on a rotary stage (22), and a weight body (24) is placed on the vacuum container (11). The weight 24
Is positioned coaxially with the vacuum vessel 11 by fitting the fitting recess 25 into the output substrate 13 of the vacuum vessel 11.

The welding electrode 33 at the tip of the welding torch 32 is moved by the moving stage 23 to the welding portion 14 of the vacuum container 11 at a predetermined distance position where good welding can be performed and positioned.

After that, the welding operation by the controller 34 is automatically performed by operating a start switch or the like of a control panel (not shown).

When the welding operation is started, the vacuum motor 11 is rotated by the rotary motor 41 and the spacing between the welding portion 14 and the welding torch 32 which are rotated by the copying mechanism 44 is controlled to be constant.

Further, when the welding execution signal is output from the control unit 34 to the welding control unit 45 of the welding power source unit 42, the welding current output unit 46 outputs the welding current preset by the volume and the like, and the welding torch is produced. A welding current is passed between the welding electrode 33 of 32 and the electrode 26 of the weight body 24 to weld the welding electrode of the welding torch 32.
33 and arc weld between the vacuum vessel 11 and the welded portion 14,
Welding of the welded portion 14 is started.

During welding, the welding current output section 46
Thus, the welding current detection signal output from the current detection unit 47 is monitored, and the welding voltage output is controlled so that the welding current becomes constant (set value). Further, the welding voltage detection unit 48 monitors the welding voltage output from the welding current output unit 46, and if the welding voltage is at a welding voltage value during normal arc welding, the control unit 34 continues welding.

During welding, the copying mechanism 44
For example, when the welding electrode 33 of the welding torch 32 comes into contact with the welded portion 14 due to a malfunction of the welding torch 32, the resistance value between the welding electrode 33 of the welding torch 32 and the welded portion 14 becomes lower than that at the normal time, so the welding current output The portion 46 lowers the welding voltage from the normal value so that the welding resistance becomes constant (set value). The control unit 34 monitors this change in welding resistance via the welding voltage detection unit 48 and determines that there is an abnormality.

On the contrary, the welding electrode 33 and the welding portion of the welding torch 32
If the distance between the welding torch 32 and the welding electrode 33 of the welding torch 32 is higher than that of the normal state, the welding current output unit 46 has a constant welding resistance (setting). The welding voltage is raised above the normal value so that Control unit
34 monitors this change in welding resistance via the welding voltage detector 48 and determines that there is an abnormality.

When the control section 34 detects an abnormality, the control section 34 outputs a welding stop signal to the welding control section 45 of the welding power source section 42 to stop the output of the welding current from the welding current output section 46 to perform welding. To stop. At the same time, the rotation motor 41 and the copying mechanism 44 are stopped.

Therefore, even if the welding electrode 33 of the welding torch 32 comes into contact with the welding portion 14 due to a malfunction of the copying mechanism 44, the vacuum container 11, the welding torch 32, and the welding device are not damaged. This can be prevented in advance, and even if the welding electrode 33 of the welding torch 32 is too far from the welded portion 14, it is possible to prevent the welding arc from becoming unstable and causing welding failure.

In each of the above embodiments, the measuring means for non-contact measurement is not limited to an optical method using a laser beam or the like, but may be a measuring means using an ultrasonic method or the like.

[0060]

According to the present invention, the distance of the welding means with respect to the welded portion can be kept constant by measuring the displacement of the welded portion in the radial direction due to the rotational eccentricity of the member to be welded without contact. In addition, it is possible to improve the quality of the member to be welded without generation of abrasion powder due to contact unlike the conventional case.
Further, when the member to be welded is mounted on the rotary stage, it is not necessary to position the measuring means, only the welding means needs to be positioned with respect to the welded portion, and workability can be improved.

During welding, the welding voltage output to the welding means can be detected to monitor the welding condition.
It is possible to stop the welding current to the welding means and stop the rotation of the welding means by judging that the welding portion and the welding means are in contact with each other or, on the contrary, too far apart from each other. It is possible to prevent welding defects of the welding members.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an arc welding apparatus showing a first embodiment of the present invention.

FIG. 2 is a front view showing a vacuum container according to the same embodiment.

FIG. 3 is a configuration diagram of an arc welding apparatus showing a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a conventional arc welding device.

[Explanation of Codes] 11 Vacuum container as a member to be welded 14 Welded portion 22 Rotating stage 23 Moving stage as moving means 31 Laser measuring instrument as measuring means 32 Welding torch as welding means 34 Control section 42 Welding power source section 43 Welding Voltage detector

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location // H01J 9/26 H01J 9/26 A (72) Inventor Minoru Shida 1385 Shimoishigami, Otawara, Tochigi Prefecture No. 1 Stock Company Toshiba Nasu Electronic Tube Factory

Claims (4)

[Claims] 1. A step of rotating a member to be welded having a welded portion on an outer periphery, a step of measuring a displacement amount of a welded portion in a radial direction due to a rotational eccentricity of the member to be rotated without contact, and a step of rotating the member to be rotated. Arc welding the welded portion of the welding member with the welding means, and moving the welding means in the radial direction in accordance with the measured displacement amount to maintain a constant distance from the welded portion. Characteristic arc welding method. 2. A step of arc-welding a weld portion of a member to be welded by outputting a constant welding current to the welding means, a step of detecting a welding voltage output to the welding means, and a detected welding voltage being normal. And a step of stopping the output of the welding current to the welding means when it is different from the welding voltage during the arc welding. 3. A rotary stage for rotating a member to be welded having a welded portion on its outer circumference, and a displacement amount of the welded portion in the radial direction due to rotational eccentricity of the member to be welded rotated by this rotary stage is measured in a non-contact manner. Measuring means, welding means for arc welding the welded part of the member to be welded, moving means for moving the welding means in a radial direction with respect to the rotation center of the rotary stage, and displacement measured by the measuring means. An arc welding apparatus, comprising: a control unit that controls the moving unit based on an amount and keeps a distance of the welding unit to a welding portion of the member to be welded constant. 4. A welding means for arc-welding a welded part of a member to be welded, a welding power source for outputting a constant welding current to the welding means, and a welding voltage for detecting a welding voltage output from the welding power source. And a control unit for stopping the output of the welding current from the welding power supply unit when the welding voltage detected by the welding voltage detection unit is different from the welding voltage during normal arc welding. An arc welding device characterized in that