JP3134545B2 - Strain control welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distortion control welding method.

[0002]

2. Description of the Related Art To butt-weld a work (plate material),
As shown in FIG. 8, works A and B having the same
, Welding works A and B having different plate thicknesses as shown in FIG. 9, and overlapping and welding the ends of the works A and B as shown in FIG. 10. When such workpieces A and B are welded, as shown in FIG. 11, when the welds solidify, the workpieces A and B undergo angular deformation δ and the quality of the product deteriorates. There is a problem that a gap or a step is generated in a portion of the welding line 1 to be subsequently welded due to the influence of the angular deformation, thereby causing a welding defect. Therefore, each work A,
Generally, B is welded in a state where it is firmly pressed against a fixed support surface by a clamp jig or the like and restrained.

[0003]

However, in the above-mentioned conventional method, since the strength of the pressing force of the works A and B depends on empirical intuition, it can be restrained by an appropriate pressing force. Therefore, if the pressing force is weak, the workpieces A and B will rise due to the distortion due to the heat effect and cause a welding defect due to angular deformation, and even if the pressing force is too large, the workpieces A and B will be displaced by the pressing force. Due to the deformation caused by warping, the welding lines 1 do not exactly coincide with each other, which causes problems such as that good welding cannot be performed. As described above, the welding quality of the workpieces A and B is greatly affected by the deformation of the workpieces A and B and the fitting accuracy of the groove. Particularly, when the workpieces A and B are thin plates, this phenomenon tends to be remarkable, and good welding is performed. Was difficult to do. The appropriate pressing force varies depending on the material, the plate thickness, the welding conditions and the like of the works A and B. However, since the pressing force is conventionally determined based on empirical insight, the above-described lifting of the works A and B occurs. Problems such as generation of welding defects could not be dealt with.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a distortion control welding method which enables high quality butt welding by always constraining a work with an appropriate pressing force. Aim.

[0005]

According to the present invention, workpieces A and B are provided.
When the butt welding is performed while pressing the workpieces against the fixed support surface while constraining them, the works A and B are fixed to the fixed support surface by the pressing device via the pressure sensors at a plurality of positions close to and along the welding line. , And the position of the work A, B in the pressing direction at this time is detected by a distance sensor and set as a set position.
A strain control welding method, wherein the pressing force by the pressurizing device is controlled so that the position detection value of the distance sensor becomes the set position with respect to the fluctuation of the reaction force of B, and the works A and B are fixed. When performing butt welding while pressing against and constraining against the support surface, a plurality of tape switches for detecting contact between the works A and B are arranged on the fixed support surface close to and along the weld line of the works A and B. And work A and B,
At a plurality of positions near the welding line and along the welding line, the pressing device is pressed against the fixed supporting surface with a constant pressing force. A strain control welding method characterized in that control is performed to increase the pressing force of a pressing device of a portion, and welding of works A and B when butt welding while pressing and restraining works A and B against a fixed support surface. A heat absorbing plate having the same upper surface as the fixed support surface is arranged below the line, and a thermometer for detecting the temperature of the works A and B is arranged along the welding line, and the works A and B are welded. At a plurality of locations near the welding line and along the welding line, the pressing device is pressed against the fixed support surface with a constant pressing force by a pressing device. Increase the pressing force of the pressure device Distortion control welding method and performing control that is intended according to the,.

[0006]

According to the first aspect of the present invention, the workpieces A and B are pressed against the fixed support surface by a pressing device at a plurality of positions near the welding line and along the welding line with a constant pressing force, and The pressing force of each pressing device is detected by a pressure sensor, and the position of the work A, B in the pressing direction is detected by a distance sensor, and the detected value at this time is set as a set position. The change in the position detection value of the sensor makes it possible to know that distortion has occurred in the works A and B. Therefore, by controlling the pressing force of the portion where the occurrence of the distortion is detected so that the position detection value of the position sensor becomes the set position, the works A and B can be surely pressed against the fixed support surface. Good welding can be performed.

According to the second aspect of the present invention, the workpieces A and B are pressed against the fixed support surface by a pressing device at a plurality of positions near and along the welding line with a constant pressing force, and Since the contacts of the works A and B are detected by the tape switch arranged on the fixed support surface at the position along the welding line, the contact of the work A and the work B is not detected as the welding progresses. , B
Can be known that distortion occurs. Therefore, by increasing the pressing force of the portion where the occurrence of the distortion is detected until the contact by the tape switch is detected, the workpieces A and B are reliably pressed against the fixed supporting surface to perform good welding. be able to.

According to the third aspect of the present invention, the workpieces A and B are pressed against the fixed support surface by a pressing device at a plurality of positions near and along the welding line with a constant pressing force, and Since a heat absorbing plate is arranged below the welding line of the works A and B to absorb the heat of the works A and B and the temperature of the works A and B is detected along the welding line by a thermometer. By detecting the high temperature portions of the works A and B as the welding progresses, it is possible to know that distortion has occurred. Accordingly, by increasing the pressing force of the portion where the occurrence of the distortion is detected so as to change in the direction of decreasing the detected temperature, the workpieces A and B can be reliably pressed against the fixed support surface to achieve good welding. It can be performed.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the first aspect of the present invention, in which works A and B are arranged on a fixed support surface 3 of a support board 2 so that welding lines 1 (grooves) face each other. Then, the holding plates 4a and 4b are arranged at positions near the welding line 1 on the upper surfaces of the works A and B in parallel with the welding line 1.

A fixed frame 5a, 5b having a gate shape integral with the support plate 2 is provided on each of the holding plates 4a, 4b.
And pressurizing devices 6a and 6b such as cylinders are disposed between a plurality of equally spaced positions in the longitudinal direction of the holding plates 4a and 4b and the fixed frames 5a and 5b.
Pressure sensors 7a and 7b such as load cells are provided between the pressure sensors 4a and 4b, respectively.

Further, the distance between the cylinder body (fixed side) of each of the pressurizing devices 6a, 6b and the upper surface of the holding plate 4a, 4b is detected to output the position detection value 25a, 25b. Sensors 24a and 24b are provided. The distance sensors 24a and 24b directly detect the distance between the workpieces A and B and the position near the welding line 1, or detect the movement of the rods (moving sides) of the pressurizing devices 6a and 6b. Various methods, such as those described above, may be employed as long as they can detect the positions of the workpieces A and B in the pressing direction.

A pressing control signal 8 is applied to the pressurizing devices 6a and 6b.
a, 8b is output to control the pressing force, and the pressing force control device 9 is provided with a pressing force previously determined based on the materials, plate thicknesses, welding conditions, etc. of the works A and B. When the set value 10 is inputted, the pressure sensors 7a,
The reaction force detection values 11a and 11b detected at 7b and the position detection values 25a and 25b of the position sensors 24a and 24b are input. In the drawing, reference numeral 12 denotes a welding device that performs welding work by a torch 14 while traveling along the welding line 1 according to a command from a welding control device 13. The welding device 12 is configured to detect a traveling position by a rotary encoder (not shown) or the like. Further, a pressing control signal from the pressing force control device 9 is input to the welding control device 13. In the figure, reference numeral 15 denotes a backing money.

In welding, the workpieces A and B are fixedly supported by pressing devices 6a and 6b at a plurality of locations near the welding line 1 and along the welding line 1 via pressing plates 4a and 4b. 3 and the pressing force P at this time
₁ (reaction force detection values 11a, 11b)
detected by b, the pressing force P ₁ that the detected is 8 to 1
The pressing force set value P ₀ (10), which is obtained in advance in accordance with the difference in the welding method shown in FIG. 1 and the materials, thicknesses, welding conditions, and the like of the works A and B and is input to the pressing force control device 9. To control.

At this time, the positions of the workpieces A and B in the pressing direction are detected by the distance sensors 24a and 24b, and the detected position values 25a and 25b are stored in the pressing force control device 9 as set positions. At this time, in order to prevent excessive pressing by the pressing devices 6a and 6b, the pressing devices 6a and 6b
Position detection value 25 when pressing with constant pressing force at b
a, 25b (position detection value 25
a, 25b minus, for example, a few hundred mm)
It is effective to set as the setting position.

In this state, welding is started, and each pressurizing device 6
a, said distance sensor 24a at a constant pressing force P ₀ by 6b, the position detection value 25a of 24b, distortion by 25b varies detects that has occurred.

The distortion of the workpieces A and B changes every moment as the welded portion melts and solidifies.
Since the position detection values 25a and 25b of 24b also change, the pressurizing devices 6a and 6a in front of the arc point are set so that the position detection values 25a and 25b become the set positions stored in the pressing force control device 9.
6b is controlled.

In this way, the works A and B are reliably pressed against the fixed support surface 3 with a minimum pressing force, and good welding can be performed in a state where the welding lines 1 of the works A and B are aligned. it can.

FIG. 3 shows an embodiment of the present invention. As in FIGS. 1 and 2, a work A is formed so that a welding line 1 (groove) faces a fixed support surface 3 of a support plate 2. , B,
Pressing plates 4a and 4b are arranged in parallel with the welding line 1 at positions near the welding line 1 on the upper surfaces of the works A and B. Further, the support plate 2 is provided on each of the holding plates 4a and 4b.
And fixed frames 5a and 5b having an integral gate shape,
Pressure sensors 7a, 7b are provided between a plurality of equally spaced positions in the longitudinal direction of the holding plates 4a, 4b and the fixed frames 5a, 5b.
The pressurizing devices 6a and 6b are arranged via the.

Further, the workpieces A, B are placed on the fixed support surface 3 at a position close to and along the welding line 1 of the workpieces A, B.
Tape switches 16a and 16b for detecting contact
Is arranged. Further, similarly to the above embodiment, the pressurizing devices 6a,
6b is provided with a pressing force control device 18 for controlling the pressing force. The pressing force control device 18 inputs a pressing force set value 10 determined in advance according to the materials, the plate thicknesses, welding conditions, etc. of the works A and B, and , Detection signals 17a and 17b from the tape sensors 16a and 16b, and pressure sensors 7a and 7b.
The reaction force detection values 11a and 11b are input.

In welding, works A and B are welded to welding line 1
At a plurality of positions close to the welding line 1 and along the welding line 1, the pressing devices 6a and 6b press the fixing support surface 3 via the pressing plates 4a and 4b, and the pressing force at this time is controlled in advance by pressing force control. Pressing force set value 1 input to device 18
Control is made constant by 0. At this time, tape switch 1
When the workpieces A and B are pressed and contact the 6a and 16b, the tape switches 16a and 16b output ON detection signals 17a and 17b to the pressing force control device 18.

As the welding progresses, the workpieces A and B are deformed by the strain as shown in FIG.
When the user moves away from the work 16b, the detection signals 17a and 17b of the tape switches 16a and 16b are turned off, so that it is possible to know that distortion has occurred in the works A and B. Accordingly, the pressing force of the pressurizing devices 6a, 6b at the portion where the occurrence of the distortion is detected is reduced by the tape switches 16a, 1b.
The pressing control signals 8a and 8b of the pressing force control device 18 are increased by the pressing device 6 so as to increase until the contact by the pressing device 6b is detected.
Outputting the workpieces a and 6b ensures that the workpieces A and B are pressed against the fixed support surface 3 and good welding is performed. Also according to this embodiment, the workpieces A and B can be pressed with a minimum pressing force that does not cause distortion during welding.

FIG. 5 shows a third embodiment of the present invention. Similar to FIGS. 1 and 2, the workpieces A and A are so arranged that the welding line 1 (groove) faces the fixed support surface 3 of the support board 2. B is arranged, and holding plates 4a and 4b are arranged in parallel with the welding line 1 at positions near the welding line 1 on the upper surfaces of the works A and B. Further, the support plate 2 is provided on each of the holding plates 4a and 4b.
And fixed frames 5a and 5b having an integral gate shape,
Pressure sensors 7a, 7b are provided between a plurality of equally spaced positions in the longitudinal direction of the holding plates 4a, 4b and the fixed frames 5a, 5b.
The pressurizing devices 6a and 6b are arranged via the.

Further, a heat absorbing plate 19 such as a copper plate is disposed below the welding line 1 of the works A and B, and the surface temperature of the works A and B is detected along the welding line 1 in a non-contact manner. Thermometers 20a, 20b are provided;
The detected temperature signals 21a and 21b are input to the pressing force control device 22. Further, a temperature set value 23 is input to the pressing force control device 22, and the thermometer 20a,
When the detected temperature signals 21a and 21b of the workpieces A and B detected by the sensor 20b exceed the temperature set value 23, the deformation of the workpieces A and B due to the distortion is detected, and the pressing force of the portion exceeding the temperature set value 23 is reduced. Increasing pressing control signal 8
a and 8b are output to the pressurizing devices 6a and 6b.

In welding, works A and B are welded to welding line 1
At a plurality of positions close to the welding line 1 and along the welding line 1, the pressing devices 6a and 6b press the fixing support surface 3 and the heat absorbing plate 19 via the pressing plates 4a and 4b, and the pressing force at this time is It is controlled to be constant by the pressing force set value 10 previously input to the pressing force control device 22.

When the welding is started, the portions of the works A and B close to the welding line 1 become high temperature by welding, but the works A and B are in contact with the heat absorbing plate 19, so that the heat absorbing action of the heat absorbing plate 19 results. As shown by the broken line in FIG. 7, the rise in the temperature becomes slow, and the maximum temperature also becomes a temperature slightly lower than the temperature set value 23. Further, the temperature set value 23 is set as described above.

When the workpieces A and B are deformed due to distortion and move away from the heat absorbing plate 19 as shown in FIG. 6 with the progress of welding, the works A and B are no longer absorbed by the heat absorbing plate 19, so that in FIG. As shown by the solid line, the temperature rises rapidly. Thus, it is possible to know that distortion has occurred in the works A and B. Therefore, the pressing force of the pressurizing devices 6a and 6b in the portion where the distortion is detected is
By increasing the temperature of the works A and B so as to be equal to or lower than the temperature set value 23, the works A and B can be reliably pressed against the fixed support surface 3 and good welding can be performed. Also according to this embodiment, the workpieces A and B can be pressed with a minimum pressing force that does not cause distortion during welding.

It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the scope of the present invention.

[0029]

According to the first to third aspects of the present invention, the workpieces A and B can be reliably pressed against the fixed support surface and butt-welded, so that a high quality can be always obtained without causing a welding defect even in a thin plate. An excellent effect that can perform welding can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of an apparatus embodying the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a front view of an apparatus for carrying out the invention of claim 2;

FIG. 4 is an enlarged front view showing the operation of FIG.

FIG. 5 is a front view of an apparatus for carrying out the invention of claim 3;

FIG. 6 is an enlarged front view showing the operation of FIG.

FIG. 7 is a diagram showing a change in the surface temperature of the work of FIG. 3;

FIG. 8 is a front view showing an example of butt welding.

FIG. 9 is a front view showing another example of the butt welding.

FIG. 10 is a front view showing still another example of the butt welding.

FIG. 11 is a front view showing an example of angular deformation by butt welding.

[Explanation of symbols]

 A Work B Work 1 Welding line 3 Fixed support surface 6a Pressurizing device 6b Pressing device 7a Pressure sensor 7b Pressure sensor 11a Reaction force detection value 11b Reaction force detection value 24a Distance sensor 24b Distance sensor 25a Position detection value 25b Position detection value

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-261595 (JP, A) JP-A-2-299777 (JP, A) JP-A-3-79048 (JP, A) 76683 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23K 9/025 B23K 31/00 B23K 37/04

Claims (3)

(57) [Claims] When butt-welding while pressing and constraining works A and B against a fixed support surface, works A and B are connected via pressure sensors at a plurality of locations close to and along the welding line. The pressing device is pressed against the fixed support surface with a constant pressing force, and the position of the work A, B in the pressing direction at this time is detected by a distance sensor and set as a set position. A distortion control welding method, wherein a pressing force by the pressurizing device is controlled so that a position detection value of the distance sensor becomes the set position with respect to a change in a reaction force. 2. When performing butt welding while pressing and constraining the works A and B against the fixed support surfaces, the works A and B are placed on the fixed support surfaces close to and along the welding lines of the works A and B. A plurality of tape switches for detecting the contact of the workpieces are provided, and the works A and B are pressed against the fixed support surface with a constant pressing force by a pressing device at a plurality of locations near and along the welding line. And a control method for increasing the pressing force of the pressurizing device at the portion where the contact between the works A and B by the tape switch is not detected until the contact is made. 3. A heat absorbing plate having the same upper surface as the fixed support surface is disposed below the welding line of the work A, B when the works A and B are butt-welded while being pressed against and fixed to the fixed support surface. At the same time, a thermometer for detecting the temperatures of the works A and B along the welding line is provided, and the works A and B are fixed at a plurality of positions close to the welding line and at positions along the welding line by a pressing device. A strain control welding method comprising: pressing against a fixed support surface with a pressing force, and performing control to increase a pressing force of a pressurizing device in a portion having a high temperature based on a temperature detected by the thermometer on the workpieces A and B. .