JPH0677835B2 - Welding equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a welding device capable of automatically performing circumferential welding of an object to be welded such as a square steel pipe having straight and curved portions. It is a thing.

(Prior art and problems) When welding a flange to the end of a square steel pipe, the work to be welded was conventionally mounted on a positioner, but with this method, the worker always uses the torch. A large amount of labor was required because the work had to be held. Various welding devices have been developed as devices for automatically performing such welding work.
There are drawbacks that the mechanism is complicated and expensive, the welding cable is twisted, continuous welding cannot be performed, and welding defects easily occur.

When welding a square steel pipe and a flange steel plate, it is general that the weld end of the steel pipe is subjected to a groove forming of about 35 degrees (α) as shown in FIG. 4 (a). Further, when performing such welding, if the axis of the square steel pipe is horizontal and the downward welding is performed while rotating around the axis, welding defects are less likely to occur, but simply turning the square steel pipe will cause As shown in FIG. 4 (b), a maximum inclination of about 40 degrees (β) occurs near the corners, so that welding defects are likely to occur.

In order to solve such a problem, “a face plate having an outer peripheral line that is equidistant from the welding line of the work, a work rotating device having means for mounting the work between the both side plates and rotating the face plate, and a drive side A frame installed over the face plate, a torch device that constantly directs the welding torch to the welding line on this frame, a traveling device that travels on the outer periphery of the face plate, and a position detection device that detects the straight and curved portions of the welding line A welding machine,
A control device that controls the traveling linear velocity of the welding machine and the rotation and stop of the work is installed.The work is mounted between the double-sided plates, the welding machine travels around the outer circumference of the face plate, welds, and the position detection device is used. Detects the straight line part and the curved line part of the welding line, the straight line part stops the rotation of the work through the control device, and the curved line part rotates the work in the direction opposite to the traveling direction and always performs the entire circumference welding downward. An automatic welding device characterized by the above has been proposed (JP-A-57-
7380), this welding device, a face plate for attaching the workpiece, having an outer peripheral line equidistant from the welding line for each workpiece,
It was necessary to have a knob that actuates a position detector that detects the straight and curved portions of the weld line. Therefore, it is necessary to prepare a dedicated face plate according to the shape and size of the object to be welded. For example, in the case of square steel pipes, even if the nominal dimensions of the sides are the same, the length of the sides is ± 1.5 mm, 600 mm when the length is 200 mm.
In this case, there is a dimensional difference of ± 9 mm, and the radius of the corners varies depending on the plate thickness and the manufacturer.Therefore, in order to perform complete welding, change the face plate for each plate thickness and manufacturer, or Alternatively, it is necessary to provide a copying device for the welding torch with respect to the object to be welded and to change the position detecting knob for each plate thickness and manufacturer.

(Object of the Invention) The present invention has been made in view of the above circumstances, can be applied to various objects to be welded, has a simple structure, and welds while always maintaining the welding line in a constant positional relationship. It is an object of the present invention to provide a welding device capable of

DISCLOSURE OF THE INVENTION A welding device according to the present invention includes a main shaft rotatably supported by a machine base, a main shaft rotating device for rotating the main shaft, and a workpiece attachment plate rotatable with respect to the main shaft. And an arm that is rotatable relative to the center of the mounting plate and that rotates together with the main shaft, and a welding head that is supported by the arm and is rotatable with respect to the arm. Facing the welding line and at least one pair of rollers that are arranged along the welding line of the pair of rollers and come into contact with the outer surface of the workpiece during welding, and a drive device that rotationally drives at least one of the pair of rollers. A welding torch is provided, and the inclination of the contact surface between the roller and the workpiece is detected during welding, and the spindle is rotated based on the detection result so that the roller and the contact surface of the workpiece are almost horizontal. An inclination detection device for rotating the device is attached It is characterized by

(Embodiment) An embodiment shown in the drawings will be described below.

1 and 2 are partial cross-sectional side views showing an example of a welding apparatus according to the present invention, and FIG. 3 is a front view showing a part of the welding apparatus. 3, a supporting device 4 for supporting the welding head 3, a workpiece mounting plate 5, and a horizontal hollow main shaft 6 to which the supporting device 4 is mounted at its tip. Hollow spindle 6
A rotating shaft 7 to which a mounting plate 5 is fixed is inserted into the core portion of the so as to be independently rotatable.

The welding head 3 has a plurality of recesses on the lower surface side, and is supported rotatably about the support shaft 8 by a support shaft 8 provided at an intermediate portion in the horizontal direction and a rod 9 of the support device 4. A motor 11 is attached to the rear end portion of the welding head 3, and a drive gear 15 is fixed to a rotary shaft 13 that is projected into the recess 12 at the rearmost portion. On the lower surface of the welding head 3,
Left and right two roller shafts 17,1 sandwiching the support shaft 8
7'side by side. Roller shafts 17, 17 'are front and rear bearings 1
A driven gear 21 which is rotatably supported by 9, 20 and which meshes with the drive gear 15 is attached to the rear end of one roller shaft 17. Further, in the middle of the roller shaft 17, the drive rollers 27, 2 located in the central recess 23 and the front recess 25 are provided.
7'is provided. The other roller shaft 17 'is rotatably provided independently of the drive gear 15, and two front and rear floating rollers 29, 29' are provided in the middle thereof. Drive rollers 27, 27 'and idle rollers 29, 29'
Is preferably made of a magnet that is magnetically attached to the object to be welded. Further, it is preferable that the outer peripheral portions of these rollers are subjected to knurling or the like to increase the frictional force. The drive rollers 27, 27 'and the floating rollers 29, 29' are provided so as to be offset from each other in the front-rear direction, and both rollers 27 (27 '), 29 (2
Since the sum of the radius (r) of 9 ') is larger than the inter-axis distance l of both roller shafts 17, 17', both rollers 27 (27 '), 2
9 (29 ') partially overlaps each other by a length d when viewed in the axial direction.

In the illustrated example, the drive rollers 27, 27 'and the idle rollers 29, 29' are all formed as rollers of equal diameter (2r),
17, 17 'and the support shaft 8 are provided side by side on a straight line when viewed from the front, but in some cases, the diameters of the drive roller and the idler roller may be different, and the support shaft 8 and the roller shafts 17, 17' are different from each other. Do not have to be arranged on the same straight line.

In addition to the drive rollers 27, 27 'and the floating rollers 29, 29', more rollers may be provided. Further, the driving roller 27 and the floating roller 29 may not be provided in the front and rear two as in the illustrated example, but may be provided in each one.

A welding torch 30 is attached to a support frame 3a protruding from the front end of the welding head 3. The welding torch 30 is provided at a position in front of the space between the roller shafts 17 and 17 ', and is supported so as to face the welding line W so that the extension line of the shaft coincides with the welding line W. The welding torch has an adjustment mechanism for adjusting the angle around the line vertical to the top and bottom, left and right, and the paper in Fig. 1 when the plate thickness and groove shape of the work piece are different and when multiple layers are required. Sometimes installed. In the figure, 30a is a welding rod (wire) which is automatically fed out by a feeding device (not shown).

Further, a mercury switch-shaped inclination detection device 31 is provided on the upper surface of the welding head 3. Since the upper surface of the welding head 3 is formed parallel to the contact surface S between the roller and the object to be welded, the inclination detecting device 31 can detect the inclination of the welding line W.

The support device 4 includes an arm 33 that horizontally projects from a support column 32.
And a support tube 35 protruding downward from the tip of the arm 33, and the base 9a of the rod 9 is slidably fitted in the support tube 35. The rod 9 extends downward due to the weight of the welding head 3 pivotally attached to its lower end, and the rollers 27, 27 ', 29, 29' are in contact with the object to be welded. It is preferable to provide an appropriate stopper to prevent the rod 9 from falling off the support tube 35 when the object to be welded is removed.

The main shaft 6 is rotatably supported by bearings 41 provided on the machine base 40. The rotary shaft 7 is supported by a bearing 41 'supported by a support column 40a and a rising portion 40b of the machine base 40. In the figure, 42 is a bushing. A base portion 32a of the support column 32 of the supporting device 4 is integrally attached to the main shaft 6. Further, a large gear 43 is fitted on the main shaft 6 adjacent to the base 32a of the column. The large gear 43 meshes with a small gear 46 attached to a rotating shaft 45 of a motor 44 installed on the bearing 41. The motor 44 and the large and small gears 43, 46 constitute a main shaft rotating device 47. The motor 44 and the inclination detection device 31 are connected via a horizontal control device 48 having a built-in electromagnetic switch, and when the welding line (the tangent line of the part currently being welded) W is inclined,
The motor 44 is started so as to rotate the main shaft 6 in a direction in which the welding line W is restored to the horizontal direction, and the motor 44 is stopped when the welding line W becomes horizontal. The driving force of the motor 44 is reduced in speed via the large and small gears 43 and 46 and transmitted to the main shaft 6.

The tilt detecting device 31 may be any device as long as it can effectively detect the tilt between the object to be welded and the contact surface of the roller. Further, the inclination detection device may not be attached to the welding head 3 as in the illustrated example, and the inclination may be detected by contacting the object to be welded near the welded portion.

When using the welding apparatus 1, first, the object to be welded is fixed to the object-to-be-welded mounting plate 5 by an appropriate fixing means such as a fixing metal fitting or a bolt so that the center of the object to be welded substantially coincides with the center of the mounting plate 5. In the illustrated example, the object to be welded is a square steel pipe 49 and a flanged square steel plate 50 welded to its end. Next, the rollers 27, 27 ', 29, 29' of the welding head 3 are placed on the upper side of the outer peripheral surface of the square steel pipe 49 which is the object to be welded, and when the motor 11 is started, the drive rollers 27, 27 'are Because it rotates, the work piece 49,50
Rotates with the workpiece attachment plate 5 due to the frictional force with the roller, and welding may be performed by turning on the welding power source in this state.

Since the welding head 3 supporting the welding torch 30 is supported by the expandable rod 9, and can be freely rotated around the support shaft 8, the corner of the square steel pipe 49 to be welded. Roller 27 (2
7 ') and 29 (29') come into contact with the outer surface of the work piece, so that the welding torch 30 is always kept in a constant direction relative to the welding spot. Further, since the inclination detecting device 31 and the turning device 47 work, the welding can be always performed from the upper side to the lower side at a constant angle with respect to the welding line W, so that a good welding state is obtained over the entire circumference. Furthermore, since the object to be welded is rotated by the drive rollers 27, 27 'on the welding head 3 side, a constant welding speed can be maintained at all times.

In this welding device, the welding head is pressed against the contact surface of the roller and the object to be welded by the weight of the welding head itself, and since each roller is magnetically attached to the steel pipe 49, the welding head is not covered. It does not separate from the welded material or move out of position. Depending on the case, a spring for pressing the welding head 3 against the object to be welded may be provided. further,
Since the drive roller 27 (27 ') and the idler roller 29 (29') are axially displaced from each other and partially overlapped with each other when viewed axially, the distance between the roller shafts 17 and 17 'is set to the roller distance. It is possible to make the diameter smaller than the diameter, and even if the copying device for the welding torch is not provided, the welding torch 30 and the welding are performed when the surface to be welded is a flat surface and when the curved surface has a small radius of curvature. The difference in distance between the points can be kept small. Further, since the main shaft 6 and the rotary shaft 7 have a double shaft structure, the entire shaft is compact even if the shaft length is increased.

In the above example, the case where electric welding is performed has been described. However, gas welding or fusing of a workpiece can be automatically performed by using a similar device.

In the illustrated example, the central axis of the object to be welded is kept horizontal, but it goes without saying that welding can be performed with the central axis tilted vertically.

(Effects of the Invention) As described above, the welding apparatus according to the present invention detects the inclination of the contact surface of the roller and the workpiece during welding,
Based on the detection result, the welding of the steel pipe or the like in the circumferential direction can be performed so that the contact surface of the roller and the object to be welded becomes substantially horizontal, so that the welding state can always be maintained in a good state. Moreover, it is mechanically simple and can be used for various objects to be welded.

[Brief description of drawings]

1 and 2 are side views showing a part of a welding apparatus according to the present invention in a cross section, FIG. 3 is a front view showing a part of the welding device, and FIG. A- in the figure
The section A and the section B-B in FIG. 2 are respectively shown. 4 (a) and 4 (b) are explanatory views of the welding method. 1 ... Welding device, 3 ... Welding head, 4 ... Supporting device,
5 ... Attachment plate for workpiece, 6 ... Main shaft, 8 ... Support shaft, 9
...... Rod, 11,44 …… Motor, 17,17 ′ …… Roller shaft,
27,27 ′ …… Drive roller, 29,29 ′ …… Floating roller, 30…
… Welding torch, 31 …… Tilt detection device, 47 …… Rotating device.

Claims (3)

[Claims] 1. A main shaft rotatably supported by a machine base, a main shaft rotating device for rotating the main shaft, a workpiece mounting plate rotatable about the main shaft, and a substantially center of the mounting plate. An arm that is rotatable relative to the main shaft and that is rotatable relative to the main shaft, and a welding head that is supported by the arm and is rotatable with respect to the arm. The welding head is installed in parallel along the welding line of the workpiece. During welding, at least one pair of rollers that come into contact with the outer surface of the object to be welded, a drive device that rotationally drives at least one of the pair of rollers, and a welding torch that faces the welding line are provided. At the same time, the inclination of the contact surface of the roller and the object to be welded during welding is detected, and based on the detection result, the inclination detection that rotates the main shaft rotating device so that the contact surface of the roller and the object to be welded becomes almost horizontal. Welding characterized by being equipped with a device Location. 2. The welding device according to claim 1, wherein the roller is made of a magnet. 3. A pair of rollers are arranged such that the axial positions of both rollers are alternately shifted so that they partially overlap each other when viewed in the axial direction, and the axial distance between both rollers is greater than the sum of the radii of both rollers. The welding device according to claim 1 or 2, which is made smaller.