JPH09300072A - Weaving device for automatic arc welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress generation of shrinkage when weaving in high speed by a crank type weaving device. SOLUTION: By fitting an eccentric pin 84 eccentric to rotation center into a cam hole 92, rotary motion of the eccentric pin 84 is converted to linear motion. Both ends of the eccentric pin 84 are made to straight parts 92a, 92d, the center part is made to an inclined part with combining two circular arc parts 92b, 92c curved in opposite directions. When the eccentric pin 84 passes one of the circular arc 92 at one side of a moving limit, linear motion is stopped, further, when the eccentric pin 84 passes other of the circular arc 92b at other side of a moving limit, linear motion is again stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weaving device for weaving a welding torch used for automatic arc welding, and more particularly to a mechanical weaving device, particularly a crank weaving device.

[0002]

2. Description of the Related Art Weaving devices for automatic arc welding are
It is roughly classified into an electromagnetic type and a mechanical type, but in general, the electromagnetic type is often used. However, the electromagnetic weaving speed is 10
It is about 20 Hz, and it is becoming difficult to cope with the recent increase in welding speed. In this respect, a mechanical type, particularly a crank type weaving device is capable of high speed weaving because of its simple mechanism and small inertia. Therefore, it can be said that the crank type is preferable from the viewpoint of high-speed weaving. As a conventional crank type weaving device, those proposed by JP-A-57-21484 and JP-A-6-66867 are well known.

[0003]

In the crank type weaving device, the rotary motion of the eccentric pin eccentric to the center of rotation is converted into reciprocating motion in the direction of the central axis of the rod, and the reciprocating motion of the rod causes welding. Weave the torch. According to this, as shown in FIG. 7, the welding torch makes one reciprocation while the eccentric pin makes one revolution, and the torch speed during this period changes in a so-called sine curve. However, in such a speed change, it has been found that when weaving is speeded up as the welding speed is increased, recesses 2 and 2 called undercuts are formed on both sides of the welding bead 1. Further, there is also a problem that vibration increases as the weaving speed increases.

In addition to these, JP-A-57-21484
The weaving device proposed in the publication has a problem that the weaving width cannot be adjusted because the rod is reciprocally moved in the axial direction simply by rotating the eccentric pin.

On the other hand, in the weaving device proposed by Japanese Patent Laid-Open No. 6-66867, the weaving width can be adjusted for the time being. However, by swinging the rod in a seesaw type and changing the position of the swing fulcrum,
Since the weaving width is adjusted, there is a problem that the device becomes large and complicated. In addition, the merit of high-speed weaving may be hindered due to the problem.

It is a first object of the present invention to provide a crank type weaving device which has less vibration even when performing high-speed weaving and can prevent the occurrence of undercut.

A second object of the present invention is to provide a crank type weaving device capable of high-speed weaving and adjustment of the weaving width, and having a small size and a simple structure.

[0008]

In order to achieve the first object, the weaving device of the present invention converts the rotational movement of an eccentric pin eccentric with respect to the center of rotation into a reciprocating movement in the direction of the central axis of the rod. Then, in the crank type automatic arc welding weaving device for weaving the welding torch, the weaving device main body that rotationally drives the eccentric pin,
In order to convert the rotational movement of the eccentric pin into a reciprocating movement in the central axis direction of the rod, a conversion member interposed between the eccentric pin and the rod is provided, and the conversion member is movably supported in the central axis direction of the rod. On the other hand, the eccentric pin operates when the eccentric pin passes through the central part of the pin fitting part, which has a pin fitting part that extends in the same direction to escape the pin motion in the direction perpendicular to the center axis of the rod. The central portion of the pin fitting portion is inclined so that the conversion member does not follow the above.

In order to achieve the second object, the weaving device body includes a housing installed near a welding torch of an automatic arc welding device, and a sleeve-shaped rotor rotatably supported in the housing. A drive mechanism attached to the housing for rotationally driving the rotor, and a first slider housed in the rotor movably in the direction of the central axis of the rotor and having a guide groove inclined with respect to the central axis of the rotor. , The rotor is penetrated from one end side into the housing and inserted into the housing, and its tip end is rotatably connected to the first slider to hold the first slider, and the first slider is held by the axial movement. A position adjustment mechanism that adjusts the position, a guide that is attached to the other end of the rotor at a right angle to the center axis of the rotor and that rotates with the rotor, and a guide While one end portion is engaged with the guide groove of the first slider, a second slider parallel eccentric pin is provided on the central axis of the rotor to the other end.

In the weaving device of the present invention, the conversion member for converting the rotational movement of the eccentric pin into the reciprocating movement in the central axis direction of the rod is movably supported in the central axis direction of the rod and is orthogonal to the central axis of the rod. Since the pin operation in different directions is escaped by the pin fitting portion extending in the same direction, there is little vibration. The center part of the pin fitting part is inclined so that the conversion member does not follow the operation of the eccentric pin when the eccentric pin passes through the center part of the pin fitting part, so the conversion member stops at both ends in the moving direction. However, the staying time at both ends of the welding torch weaving becomes longer.

It is desirable that the inclined portion of the pin fitting portion is a combination of two circular arc portions having the same bending radius and the opposite bending direction as the rotating arc of the eccentric pin. In this way, when the conversion member is located near both movement limits, the conversion member stops when the eccentric pin passes through the two circular arc portions and passes through either one of the circular arc portions. That is, if the conversion member stops when passing through one circular arc portion at one movement limit, the conversion member stops when passing through the other circular arc portion at the other movement limit. Therefore, the conversion member stops at both movement limits.

Further, in the weaving device main body, when the rotor is rotated in the housing, the second slider attached to the other end of the rotor via the guide rotates, and the eccentric pin provided at the other end. Turns around the center axis of the rotor. As a result, the rod reciprocates in the axial direction, and the welding torch weaves. Here, the position adjusting mechanism moves the first slider in the rotor in the central axis direction of the rotor. Then, guided by the guide groove of the first slider, the second slider moves in a direction perpendicular to the central axis of the rotor. As a result, the distance from the eccentric pin to the center of rotation changes, and the weaving width is adjusted. Since the first slider in the rotor is connected to the rotor via the second slider and the guide, it rotates together with the rotor. Since the position adjusting mechanism is rotatably connected to the first slider, it does not hinder its rotation.

[0013]

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

FIG. 1 is a plan view showing the appearance of an example of a weaving device embodying the present invention, and FIG. 2 is a view A in FIG.
3 is a cross-sectional plan view showing the weaving device main body, FIG. 4 is a view taken along the line B in FIG. 3, FIG. 5 is a view taken along the line C in FIG. 3, and FIG. 6 is a cam hole shape of the conversion member. It is an explanatory view of and operation.

As shown in FIGS. 1 and 2, this weaving device includes a weaving device main body A for rotating an eccentric pin 84 which is eccentric with respect to a rotation center, and an eccentric pin 8.
The eccentric rotation motion of No. 4 is converted into a linear reciprocating motion in a direction perpendicular to the rotation center, and a rod 100 that repeats the reciprocating motion in the central axis direction by the linear reciprocating motion.

The weaving device body A is a horizontal substrate 1.
On the surface of 0, the housing 20 is screwed with its central axis oriented horizontally. The housing 20 is a sleeve whose head surface is closed and whose bottom surface is open.

Inside the housing 20, as shown in FIGS. 3 and 4, a cylindrical rotor 30 is rotatably accommodated and held concentrically via a plurality of bearings 31, 31. Further, the rotor 30 is provided on the outer surface of the housing 20.
A drive mechanism 40 for rotationally driving the is attached.

The drive mechanism 40 comprises a motor 41 and two gears 42 and 43. The gear 42 of the first stage is the motor 4
1 is connected to the output shaft. The second gear 43 is 1
The gear 42 meshes with the gear 42 of the stage and also meshes with the gear portion 32 provided on the outer peripheral surface of the rotor 30. Accordingly, when the motor 41 operates, the rotation is transmitted to the gear portion 32 of the rotor 30 via the gears 42 and 43, and the rotor 30 rotates in the housing 20.

A first slider 50 having a piston-like shape is housed in the rotor 30 concentrically and movably in the central axis direction. The head portion of the first slider 50 is a column portion 51, and the bottom portion is a fin portion 52 extending from the column portion 51. The fin 52 has a center axis of 45
A guide groove 53 inclined at an angle of ° is formed so as to penetrate the fin portion 52. Then, the first slider 50
The position of the shaft is adjusted by a position adjusting mechanism 60 attached to the head portion of the housing 20 in the axial direction.

The position adjusting mechanism 60 has a horizontal screw rod 61 screwed into the center of the head surface of the housing 20.
The bottom portion of the screw rod 61 is the cylindrical portion 5 of the first slider 50.
It is rotatably connected to the central portion of the bearing 1 through a plurality of bearings 62, 62. The first rod 50 is held in the rotor 30 by the screw rod 61. In addition, by rotating the screw rod 61 and changing the screwing amount, the first
The slider 50 moves axially within the rotor 30, and its axial position is adjusted.

As shown in FIGS. 4 and 5, the bottom surface of the rotor 30 has a pair of Ls with the central axis of the rotor 30 interposed therebetween.
M guides 70, 70 are attached. The LM guides 70, 70 are at right angles to the central axis of the rotor 30, and the rail portions of the LM guides 70, 70 also serve to hold down the bearing 31.
It is screwed to the central fin portion 34 of the zero bottom plate 33.
Then, the LM guides 70, 70 guide the second slider 80 in a direction perpendicular to the central axis of the rotor 30.

The second slider 80 has a pair of side plates 81, 81 arranged with the central axis of the rotor 30 interposed therebetween. Each bottom part of the side plates 81, 81 is L
Located on both sides of the M guide 70, 70, the LM guide 70,
Associated with each of the 70 slide blocks. On the other hand, the head portions of the side plates 81, 81 are connected to the first slider 5 by
Pins 82 located on both sides of the fin portion 52 of 0 and penetrating the guide groove 53 provided in the fin portion 52 allow the first slider 5 to move.
It is connected to 0. As a result, when the first slider 50 in the rotor 30 moves in the central axis direction, the second slider 50
The slider 80 is guided by the guide groove 53 of the first slider 50 and the LM guides 70, 70 and moves in the direction perpendicular to the central axis of the rotor 30.

The bottom portions of the side plates 81, 81 are connected to each other by a bottom plate 83. An eccentric pin 84, which is parallel to the central axis of the rotor 30, is provided on the bottom surface of the bottom plate 83 so as to be offset from the central axis. Reference numeral 35 denotes a cap attached to the bottom plate 33 of the rotor 30 from the bottom side to rotate together with the rotor 30, and the eccentric pin 84 projects to the bottom side through a long hole provided on the bottom surface thereof.

A conversion member 90 for converting the rotational movement of the eccentric pin 84 into a linear movement is provided on the bottom side of the weaving apparatus main body A, and a slider 93 attached to the end surface on the bottom side is screwed onto the substrate 10. Guide 91
Is guided in the horizontal direction perpendicular to the center of rotation of the eccentric pin 84. The conversion member 90 includes the eccentric pin 8
4 has a cam hole 92 into which it fits, and is connected to one end of the rod 100. The rod 100 includes the conversion member 9
It is parallel to the moving direction of 0 and is movably supported in the axial direction by a block 101 screwed onto the substrate 10. The other end of the rod 100 is connected to a welding torch of an automatic arc welding device (not shown).

As shown in FIG. 6, the cam hole 92, which is a fitting portion into which the eccentric pin 84 is fitted, allows the movement of the eccentric pin 84 in the direction perpendicular to the moving direction of the converting member 90 to escape.
It is a long hole extending in the same direction. Both ends of the cam hole 92 are straight portions 92a and 92d perpendicular to the moving direction of the conversion member 90.
However, the center portion is inclined with respect to both ends, and more strictly speaking, two arc portions 92b, which are curved in opposite directions,
The shape is a combination of 92c. The radius of curvature of the eccentric pin 84 corresponds to the radius of rotation of the eccentric pin 84.

Next, the operation of the weaving device will be described.

When the motor 41 of the drive mechanism 40 is operated, its rotation is transmitted to the gear portion 32 of the rotor 30 via the gears 42 and 43, and the rotor 30 rotates. Rotor 30
When is rotated, the LM guide 7 attached to its bottom surface
0 and 70 rotate, which causes the second slider 80 to rotate. As a result, the eccentric pin 84 revolves around the central axis of the rotor 30, and the conversion member 90 makes a reciprocating linear motion, whereby the rod 100 reciprocates in the axial direction. Thus, the cranking type welding torch weaving operation is performed.

When the second slider 80 rotates, the first slider 50 connected thereto also rotates. Therefore, the first slider 50 in the rotor 30 also rotates with the rotor 30. That is, the rotor 30, the first slider 50, and the second slider 80 rotate synchronously. Position adjustment mechanism 60
Since the bottom portion of the threaded rod 61 is rotatably connected to the first slider 50, does not hinder the rotational movement of the first slider 50.

The conversion member 90 is rotated along with the rotation of the eccentric pin 84.
When the reciprocating linear motion is performed, the eccentric pin 84 moves the conversion member 9
It reciprocates in the cam hole 92 formed in 0. As shown in FIG. 6, when the rotation arc of the eccentric pin 84 is divided into 36 equal parts and the conversion member 90 is displaced most toward the one end side in the moving direction,
That is, when the position at one of the movement limits (referred to as the retreat limit) is the “0” position, the eccentric pin 84 is located at the center of the cam hole 92, that is, between the arc portions 92b and 92c at the “0” position.

While the eccentric pin 84 rotates from the "0" position to the "3" position, the eccentric pin 84 passes through the circular arc portion 92c. Here, the arc portion 92c is curved in the same direction as the rotating arc of the eccentric pin 84 and has the same radius as the rotating arc. Therefore, while the eccentric pin 84 rotates from the "0" position to the "3" position, the conversion member 90 does not move forward, but is stopped at the backward limit.

While the eccentric pin 84 rotates from the "3" position to the "15" position, the eccentric pin 84 reciprocates on the straight portion 92d. Therefore, during this period, the conversion member 90 advances along the sine curve.

The eccentric pin 84 moves from the "15" position to the "18" position.
While rotating to the position, the eccentric pin 84 is again moved to the arc portion 92c.
Pass through. Here, the arc portion 92c has the same radius as the rotating arc of the eccentric pin 84, but the direction is opposite. Therefore, the conversion member 90 moves forward at a speed slightly higher than the sine curve, and reaches the other movement limit, that is, the forward movement limit.

The eccentric pin 84 moves from the "18" position to the "21" position.
While rotating to the position, the eccentric pin 84 passes through the arcuate portion 92b. Here, the arc portion 92b is curved in the same direction as the rotating arc of the eccentric pin 84 and has the same radius as the rotating arc.
Therefore, while the eccentric pin 84 is rotating from the "18" position to the "21" position, the conversion member 90 does not retract but remains in the forward limit.

The eccentric pin 84 moves from the "21" position to the "33" position.
While rotating to the position, the eccentric pin 84 reciprocates on the straight portion 92a. Therefore, during this period, the conversion member 90 retracts along the sine curve.

While the eccentric pin 84 rotates from the "33" position to the "0" position, the eccentric pin 84 passes through the circular arc portion 92b again. Here, the arc portion 92b has the same radius as the rotation arc of the eccentric pin 84, but the direction is opposite. Therefore, the conversion member 90 retreats at a speed slightly faster than the sine curve, and returns to the retreat limit.

Thus, the conversion member 90 repeats forward and backward movements while stopping at the backward limit and forward limit for a predetermined time. Therefore, the welding torch connected to the conversion member 90 via the rod 100 has a long staying time at both end positions of the weaving, whereby undercuts on both sides of the welding bead can be prevented. This staying time depends on the arc portions 92b and 92.
It can be arbitrarily adjusted by changing the circumference of c.

By operating the screw rod 61 of the position adjusting mechanism 60,
When this is moved in the axial direction, the first slider 50 in the rotor 30 moves in the axial direction. Then, the pin 82 of the second slider 80 moves in the direction perpendicular to the central axis of the rotor 30 by being guided by the guide groove 53 formed in the fin portion 52 of the first slider 50 in an inclined manner. That is, the second slider 80 is guided by the LM guides 70, 70 and moves in the direction perpendicular to the central axis of the rotor 30. As a result, the distance from the eccentric pin 84 to the center axis (rotation center) of the rotor 30 changes, and the weaving width of the welding torch is adjusted.

Since a mechanism for adjusting the weaving width (first slider 50, LM guides 70, 70 and second slider 80) is provided from the inside of the rotor 30 to its bottom side and concentrated around the center of rotation. , The inertia is small, and the merit of high speed weaving by the crank type is not hindered.

[0039]

As described above, since the weaving device of the present invention is of the crank type, it is possible to perform high-speed weaving, which contributes to speeding up of automatic arc welding.
Even when high-speed weaving is performed, the vibration is small and the undercut can be prevented from occurring.

In addition, despite being of the crank type,
The weaving width can be adjusted. Regarding the weaving width adjustment mechanism, 2
Since the two sliders are connected and interlocked with each other so that the mechanism is concentrated around the rotation center, the structure is small and the structure is simple, and an increase in inertia is avoided, so that high-speed weaving is not hindered.

[Brief description of drawings]

FIG. 1 shows a weaving device 1 embodying the present invention.
It is a top view which shows the external appearance about an example.

FIG. 2 is a view taken in the direction of the arrow A in FIG. 1;

FIG. 3 is a cross-sectional plan view showing the weaving device body.

FIG. 4 is a view on arrow B of FIG. 3;

5 is a view taken in the direction of the arrow C in FIG.

FIG. 6 is an explanatory diagram of a cam hole shape and an operation of the conversion member.

FIG. 7 is a schematic view showing an operation and a problem of a welding torch by a conventional weaving device.

[Explanation of symbols]

 A weaving device main body 10 substrate 20 housing 30 rotor 40 drive mechanism 50 first slider 53 guide groove 60 position adjusting mechanism 70 guide 80 second slider 84 eccentric pin 90 conversion member 92 cam hole (pin fitting portion) 100 rod

Claims (3)

[Claims] 1. A rotary motion of an eccentric pin, which is eccentric with respect to the center of rotation, is converted into a reciprocating motion in the direction of the central axis of the rod,
In a crank-type automatic arc welding weaving device that weaves a welding torch, the weaving device body that drives the eccentric pin to rotate, and the eccentric pin and the rod to convert the rotational motion of the eccentric pin into a reciprocating motion in the central axis direction of the rod. And a conversion member interposed between the conversion member and the conversion member. The conversion member is movably supported in the central axis direction of the rod, and extends in the same direction in order to escape the pin operation in the direction perpendicular to the central axis of the rod. It has a pin fitting part, and the center part of the pin fitting part is inclined so that the conversion member does not follow the operation of the eccentric pin when the eccentric pin passes through the center part of the pin fitting part. Weaving device for automatic arc welding. 2. The inclined portion of the pin fitting portion is a combination of two circular arc portions having the same curving radius and opposite curving directions as the rotating circular arc of the eccentric pin. Weaving device for automatic arc welding. 3. The main body of the weaving device includes a housing installed near a welding torch of an automatic arc welding device, a sleeve-shaped rotor rotatably supported in the housing, and a housing for rotating the rotor. The attached drive mechanism is housed inside the rotor so as to be movable in the direction of the central axis of the rotor,
A first slider having a guide groove inclined with respect to the center axis of the rotor; A position adjusting mechanism that holds the first slider and adjusts the holding position of the first slider by axial movement; a guide that is attached to the other end of the rotor at a right angle to the central axis of the rotor and rotates with the rotor; A second slider which engages with the guide and has one end engaged with the guide groove of the first slider and the other end provided with an eccentric pin parallel to the central axis of the rotor. Item 3. A weaving device for automatic arc welding according to item 1 or 2.