JPS6030583A - Automatic welding device - Google Patents

Abstract

PURPOSE:To weld rationally a work having a circular or rectangular section by providing torches to the ends of turning shafts suspended from a lifting base, disposing the weld zones of the work on the extension of the turning shafts and swiveling the above-mentioned torches around the outside circumference of the weld zones in a circular locus. CONSTITUTION:Working members 10 provided with welding torches T equal to the welding torch at the points of a work W at the bottom ends of turning shafts 11 are suspended from a lifting base 3 which is vertically moved by a cylinder C0 installed in the upper part of a machine bed 1. Members for swieveling and driving the torches and members for detecting turning angles are provided to the members 10. The weld zones of the work W are then disposed on the extension of the central line of the shafts 11. The electrode tips of the torches T are disposed to face the outside of the weld zones deviated from the centerline and the torches T are swiveled around the outside circumference of the weld zones in the circular locus by the rotational driving of the shafts 11, by which the plural weld zones are welded at one time of welding cycle. The work having the circular or sectional section is thus welded with the plural torches without requiring a costly CNC control device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic welding device equipped with a plurality of welding torches, which is capable of rationally welding workpieces having a circular or rectangular cross section.

In recent years, with the development of industrial robots, a welding torch is held on the robot's wrist, and the teaching play method is used to
Welding robots that perform welding work on workpieces of arbitrary shapes are becoming widespread. In addition, specialized automatic welding equipment is available for welding workpieces of a specific shape with one or several sets of welding torches, and this automatic welding equipment can be used alone to automatically feed and eject workpieces using a conveyor pallet. You can see what you made. The advantages of the above automatic welding equipment are C.
The NC numerical control device is designed to allow highly accurate welding by programming the workpieces to be welded and various correction functions. However, CNC control equipment is expensive, and when multiple torches are installed to perform simultaneous welding, multiple control equipment and welding robots are required, resulting in enormous programming and equipment costs. There is a drawback.

To prevent this, welding multiple locations with one set of welding torches would take a lot of time (and heat distortion would occur on the workpiece due to repeated heating). A problem will occur.

In order to eliminate the above-mentioned drawbacks found in conventional automatic welding equipment, the present inventor (1) aims to:
Ability to weld workpieces with circular or rectangular cross sections. (2),
To not require the same number of robots even when using multiple sets of welding torches. (3) Multiple welding locations on one workpiece can be completed in one welding cycle. (
4) We have successfully developed a welding technology that eliminates heat distortion of the workpiece.

First, the present invention targets a welded part having a circular or rectangular cross section, and uses a welding method in which a welding torch is moved around the outer periphery of the workpiece welded part in a circular trajectory.

That is, the welding torch is suspended from a rotating shaft that can be rotated and moved up and down by a single drive source, and the direction of the torch can be changed by a swinging mechanism as necessary, without using an expensive CNC control device. In addition to simple circular or rectangular outer circumferential surfaces, complex welding of circular or rectangular outer circumferential surfaces in which the welding portion changes can be achieved by a simple means.

In addition, in the present invention, when a workpiece has a plurality of welded parts, the welding torch is attached to a rotating shaft of an operating member arranged corresponding to the welded part, and these rotating shafts are individually driven. At the same time, one 7 cutter allows for a large retraction when replacing the workpiece. Now, even if there are multiple welds on one workpiece, the welding cycle can be completed in one cycle, minimizing thermal distortion of the workpiece, and requiring the same number of robots as welding 1. It is possible to provide an automatic welding device that is inexpensive and has good operability.

The automatic welding apparatus of the present invention will be briefly described below with reference to the drawings.

FIG. 1 shows the automatic welding device AW of the present invention, in which the ball l-P
Each welding torch T... is suspended from the welding part (four locations) W' of the workpiece W carried in. Each of the welding torches T... is attached to a rotating shaft 11... that protrudes from the lower end of the main body operating portion 10.... This actuating member 10... is connected to support columns 2... installed at the four corners of the machine base 1.
It is placed on a lifting platform 3 on which bearings 3α are fitted and locked to upper guy 1' rods 2a. Each guide rod, 2 (
A plate 5 is installed between the two plates 4α and 44 that are connected between the top ends of Z..., and a cylinder 5 is attached to the center of the plate 5. The tall rod 6 is connected to a mounting flange 3b at the center of the upper surface of the lifting platform 3, and when the rod 6 is at the top dead center due to the operation of the cylinder Co, each weld 1, - T,...
・ is in the raised evacuation position as shown in the figure, and the work W
The baren (ballen) P on which it is loaded is carried into and out of the table 50. Further, when the rod 6 of the cylinder co is at the bottom dead center position, the welding torch T' approaches and faces the outside of the workpiece W, and the electrode tip t is brought into contact with the welded part W' of the workpiece W. ing. Motor IV with reducer that becomes the turning drive member
II r Rotation axis 1 with normal rotation drive of M2, M3, and M4
1... rotates at a low speed, the torch T'... moves the outer periphery of the welded part Wl with a rectangular cross section to a, h, c, t as shown in FIG.
It turns about 270 degrees, drawing a circular locus 2 with radius γ as shown in t. When the welding torch T... is turned up to 270 degrees, it is moved up and down by the elevating member of the built-in cam means according to the height fluctuation of the welding part, and the cylinder CI is moved according to the inclination of the welding surface. It is changed downward like a torch T' via a link type swinging mechanism K.

Next, detailed configurations of each part of the present invention will be explained. First, second,
In FIG. 3, the actuating members 10 of four sets of welding torches T on the lifting table 3 are placed with their midsections inserted into through holes 7a formed on the seat plate 7. Reduction gear motors M, -M, and l are installed on the respective seat plates 7 on the left and right outer sides. The seat plate 7 above has holes 7h in the four corners.
... is opened, and as shown in Fig. 5, it is tightened on the lifting platform 3 with the bolt 8 through the large washer 9..., and the gap between the hole 7b and the bolt 8 is 1 minute. The attachment position can be adjusted. The exact positioning of each of the two directions (left and right, front and rear directions) in each seat plate 7 ... is a set screw of each of the plackets 12.13 opposite to the outer two sides 14.15-.
This is done by bringing the two outer sides of the seat plate 7 into contact with each other and tightening the bolts 8. That is, the relative distance between the electrode tip t of the welding torch T and the welding portion W' of the workpiece W on the pallet P can be finely adjusted.

Next, the operating member 10 that rotates, raises and lowers, and swings the welding I/-T provided at the lower end will be explained. 20 is a cylindrical housing in the middle part, and an upper flange 20. is bolted to the seat plate 7, and a rotating shaft 11 is inserted through the center thereof, and the rotating shaft is supported by bearing sleeves 21, 22 at the upper and lower ends. 23 is a cylindrical cam that fits on the rotating shaft 11 in the cylindrical housing 20. A cam follower 24 fixed to the side wall of the housing 20 is engaged in the cam groove 23°, and is rotated by the motors M1 to M4. When the rotary shaft 11 is moved, the rotary shaft 11 moves in the vertical axis direction according to the height of the cam groove 23a. In the drive system of the rotating shaft 11, a pulley 26 of a deceleration output shaft 25 of the motor M1-M4 is connected to a pulley 29 of a driven shaft 28 via a belt 27. This driven shaft 28 is supported at its midsection by a top bearing 30a of a bracket 30 connected to the top surface of the cylindrical housing 200, and has a blind hole 2 in a lower large diameter portion 28a.
The top of the rotating shaft 11 is inserted into the inside of the rotating shaft 8b. 31 is a key member attached to the side wall of the lower end large diameter portion 28.0, and is a key member attached to the side wall of the lower end large diameter portion 28.0.
Notch surface (engaging surface with key) 1 of rotating shaft 11 inserted inside
1a faces the inner surface 31a of the key member 31. When the driven shaft 28 rotates at a low speed (welding speed) by starting the motor M3, the rotating shaft 11 connected thereto also rotates together with the cam groove 23 of the cylindrical cam 23 (Z). It also moves in the axial direction in height.The amount of movement y is the key member 31
This is the gap between the notch surface of the rotating shaft 11 and the notch surface of the rotating shaft 11 that engages with the rotating shaft 11 facing each other.

Note that the rotation angle of the driven shaft (rotation shaft 11) 28 is determined by the rotation restriction member 60 that receives the key member 31 by the stop bins 32 and 33 attached to the inner wall surface of the bracket 30, as shown in FIG. The structure is set to have a rotation angle of approximately 270 degrees (the rotation angle of the welding torch T is 270 degrees). On the other hand, a bracket 34 equipped with a link type oscillating mechanism K is attached to the lower end of the rotation shaft 11 by fitting its boss 35, and a welding torch T is equipped at the tip of the link mechanism. , the direction of the torch T can be changed in two directions: the solid line and the chain line. In other words, the link mechanism that becomes the swinging mechanism is
Two long and short rod rods 36.37 are pivoted at the upper and lower positions of the bracket 34 at the middle and right end sides by support shafts 38.39, and at the two left ends of the rod rods 36.37 are relay rods 40 of the same length. ．．
41 hangs down in parallel, and its upper end and middle form a parallelogram link pivoted by four support shafts. ”2 Chronicles 2
A holder 42 is pivotally attached to the lower end of the book's relay rod 40.4j, and a welding torch T is attached to the holder 42.
are installed in the same direction. The electrode tip t of the torch T is located on the extension line y connecting the support shafts 38 and 39, and this is set at a position offset by γ from the center line 0 of the rotating shaft 11 (radius τ from the center line). It is being C1 is welding 1
- This is a cylinder that serves as the swing actuator of the T. The cylinder body side is pivotally attached to the lower end head of the bolt 43 screwed into the boss 35, and the bifurcated connecting tool 45 attached to the lower end (tip) of the rod 44 is connected to the rod rod. The adjustment screw 46 is pivotally supported between the inner end head portion of the adjustment screw 46 so as to be connected and pivotally supported at any position on the right side of the adjustment screw 36. Therefore, the third torch T is activated by the operation of the cylinder itself.
It oscillates between the solid line and the chain line in the figure, and the oscillation angle is adjusted by an adjustment screw 46. In the above action, since the electrode tip coincides with the extension line 1,
It is not displaced by a swinging motion, it simply changes its direction. Therefore, the welded part W' of a workpiece W having a smaller radius than the eccentricity γ of the torch T, for example a workpiece with a rectangular cross section as shown in FIG. When the rotating shaft is rotated slowly at a welding speed by driving M4, the electrode tip t of the torch T will rotate around the outer periphery of the welding part W' with the eccentricity r as a radius.

The timing of the upward and downward direction changes with respect to the turning movement of the torch T is from the starting point a to the ending point d as shown in FIG.
Limit switches LSI and LS2 are placed at arbitrary positions within a rotation angle of about 270 degrees, and the limit switches actuate the cylinder C1 to change the direction using the oscillation mechanism K. In the diagram, when the turning angle is 90° from the starting point α, the limit switch LSI, L is located at the end point d, which is 270°.
S2 is arranged, and the torch T is switched upward and downward at these two locations.

In addition, in the diagram, two sets of glue switches LSQ and LSe are installed at the starting point α and ending point d to ensure that the switches operate properly.
The turning motors M1 to M4 are controlled to start, stop, and reverse by operating one of the switches. The mounting relationship of the limit switch groups LSI to LS is as shown in FIG.
Limit switch groups LS1 to LS are stacked at 0h,
The rotation angle detection member 70 is configured to operate each limit switch LS, -LS, and L by a dog DI-Dn fitted on the top end side of the driven shaft 280. (The description of the electric control circuit serving as a sequencer is omitted.) The automatic welding apparatus AW of the present invention is constructed as described above, and its operation will be described below. In the device of the present invention,
Since it is possible to weld up to 4 places at the same time, the 8th
As shown in the figure, members W, , Wl are gently bent into a V-shape, and an elongated U-shaped member w2 . An example of a workpiece W in which the workpiece w2 is framed into a square and four half-cut edge surfaces thereof are welded will be described. The welded part W'... in this work W has a rectangular cross section as shown in FIGS. 7 to 9, and has a high flat edge in the turning section a-b and a turning section b.
- Slope side from high part to low part at c and turning section c -
The lower flat edge at cl, the center of which is the rotation axis 11
By moving the seat plate 7, the heights of the torches T are aligned with the extension line O of the starting point a.

First, the workpiece W attached to the pants LP is carried onto the table of the automatic welding apparatus AW and positioned at a fixed position. At this time, as shown in FIG. 1, when the lifter Co lowers the lifting platform 3 by the rising operation of the cylinder CO, each torch T... As shown in FIG. 3), the tip of the electrode is opposed to the starting point a of the weld W'. In addition, each torch T... is used for the welding part Wl of the workpiece W.
The motors M1 to M4 are opposed to the starting point a of FIG. As a result, the limiter at the starting point σ position]・switch LSO
is activated and begins to flow welding current, while the
By the rotation of the rotation shaft J1 connected through the welding torches T, each welding torch T... is rotated along a circular locus μ in the clockwise and counterclockwise directions as shown in FIG. This turning speed is the welding speed, and a
-b, each welding torch T welds, for example, TLg, the high flat edge of the welding portion W' with the electrode tip facing upward as shown by the solid line in FIG.

In the next 90° section (b - c), since the welding part W' has an inclined side from the high part to the low part, the electrode tip should be aligned with this inclined side as the rotation axis 110 rotates. The cylindrical cam 23 that engages with the cam follower 24 descends on the inclined surface of the cam groove 23cl, and the rotating shaft 11 and welding l.
ChiT also descends. These relationships are as shown in the operation flowchart in Figure 10, where limit switches LS,
is activated to drive the cylinder C1, and as shown in FIG. 3, the oscillating mechanism quickly directs the torch T downward as shown by the chain line. In the 90° turning section of c-d, the welded part W' is the flat edge of the lower part, and the parts HW, , w are directly below. Rotate without changing.

Welding 1--T can be performed by a simple turning motion around the rectangular outer periphery of the welded portion W' of the workpiece W while drawing a circular locus μ. When the torch T reaches the end point d, the limit switch LS2 is activated to cut off the welding current, while the cylinder Co is activated to raise the lifting platform 3, and the limit switch LSe is activated to start each motor M1 to
M4 is driven in reverse all at once, and this moves each torch T to d −
Rotate in direction a and return. During this return swing operation, the pallet P containing the welded work W on the table is carried out by the action of the 1-limit switch (not shown) of the cylinder CO, and the pallet P carrying the welded work W on the table is replaced by a pallet P on which a new unwelded work W is placed. is carried onto the table. In addition, when each welding torch T passes point b during the return rotation movement, the IJE throat switch LS is activated again to restore the cylinder CI,
Return the welding torch T upward as shown by the solid line in Figures 1 and 3. Of course, in the section c-b, the cylindrical cam 23 that engages with the cam follower 24 rises, and the welding torch T integrated with it also rises in preparation for the next welding. After this, cylinder Co
As a result of the operation, the lifting table 3 is lowered, and the electrode tip t of each welding torch T is aligned with the starting point a of the welding part W/ of the new workpiece W, and the automatic welding operation described above is repeated. In addition, when the target workpiece has the same height on the outer circumferential surface to be welded and there is no need to change the direction of the torch, the present invention may be configured to be used with the lifting part removed and the 6-shake mechanism removed. The design is not limited to the above, and design changes can be made within the gist. For example, the ideal cross-sectional shape of the welding part W/ is a circular cross-section, and any cross-sectional shape (hexagonal, pentagonal, triangular) that approximates this is a workpiece to be welded. Further, although simultaneous welding at several locations is performed on one workpiece W using a plurality of sets of welding torches, the number of torches must be increased or decreased depending on the workpiece. Further, design changes in detailed parts are not limited to the above embodiment. For example, the motors M1 to M4 may be directly attached to the bracket 30, and the driven shaft 28 may be directly driven by the output shaft 25 without using the belt 27. Then, the positioning stop of [Rotation axis] 1 is made to stop only the motor using a limit switch, and the rotation regulating member 60 is omitted and the rotation angle detection member 70
Modog D1 to DrL Mitswitch LS 1 =
The present invention is not limited to the LSn method.

When using the automatic welding apparatus of the present invention, an operating member provided at the lower end of a rotating shaft, which is a welding torch, which is equivalent to the welding location, is suspended from a lifting platform that is installed above the machine base and moves up and down by a single drive source. , the operating member is provided with a rotation drive unit side of the welding torch, a rotation angle detection member, etc., and the welding part of the workpiece is arranged on the extension of the center line of the rotation axis, and the electrode tip of the welding torch is The welding torch is placed facing the outside of the welded part removed from the weld line, and the welding torch is rotated around the outer periphery of the welded part in a circular trajectory by the rotational drive of the rotating shaft, so there is no need to use an expensive CNC control device. Simple welding of a circular or rectangular outer circumferential surface or complex welding of a circular or rectangular outer circumferential surface in which the welding part changes can be performed with a simple method.Furthermore, even if one workpiece has multiple welded parts, one The welding cycle is completed in 10 times, minimizing thermal distortion of the workpiece, and with the same number of welding cycles as the welding torch.
This has the effect of providing an automatic welding device that is inexpensive and has good operability, consisting of one drive system and control system, which does not require a pot.

[Brief explanation of the drawing]

Fig. 1 is a front view of the automatic welding device of the present invention, Fig. 2 is a sectional view taken along the line I-I in Fig. 1, Fig. 3 is a sectional view of the operating member that is the main part of the invention, and Fig. 4 is a sectional view of the automatic welding device of the present invention. 11-I line sectional view in the figure, FIG. 5 is a partial sectional view showing the installation of the seat plate, and FIG.
1H line sectional view, FIG. 7 is an operational sectional view showing the rotation locus of the welding torch with respect to the welding part and the arrangement relationship of each limit switch, and FIG. 8 is a perspective view of a framework work showing an example of use in the automatic welding device of the present invention. FIG.
FIG. 0 is a flowchart of the automatic welding apparatus of the present invention. 1... Machine platform, 2... Support, 3... Lifting platform, Co.
... Cylinder, 10... 9 operating members, 11... Rotating shaft, swing drive member (M1 to M4... Small motor with reducer, 27... Belt, 28... Driven shaft), Lifting member (23... cylindrical cam, 24... cam follower, 1.
1 ct...notch surface, 31...key part), 34...
...Bracket, swing plate structure K (36, 36...pole rod, 40.41...relay rod, C1...cylinder), rotation angle detection member 70 (DI~Dn...tonk, LS1～
LS? +, ... limit switch), 0 ... center line, r ... eccentricity, T ... welding torch, t ... electrode tip, U ... circular locus, W ... workpiece, W′...Welded part. Applicant Tatsushu Seisaku Co., Ltd. Han 4 Han 20 15 Tamiyo 6 Menp Audience 8 En 19 Group

Claims (1)

[Claims] An actuating part member equipped with a welding torch at the lower end of the rotating shaft, which is the same as the welding part, is suspended from a lifting platform that is built on the top of the machine base and moves up and down by a single drive source, a rotation driving member, a rotation angle detection member, etc., the welding part of the workpiece is arranged on an extension of the center line of the rotation axis, and
An automatic welding device characterized in that the electrode tip of the welding torch is opposed to the outside of the welding part away from the center line, and the welding torch is rotated around the outer periphery of the welding part in a circular trajectory by the rotational drive of the rotation shaft to perform welding. .