JPS5973185A - Automatic welding method by general-purpose type welding robot - Google Patents

Abstract

PURPOSE:To perform automatic welding with a general-purpose type welding robot wherein respective movable parts are controlled by a pattern signal and a sensor signal by holding a torch at the bottom end of a rotatable spindle mounted to a frame which is driven longitudinally, transversely and vertically and swiveling, moving forward and backward and tilting the torch. CONSTITUTION:A girder 2 moves forward or backward as an axle 29 is driven by a motor 25. A moving carriage 3 is moved to the right and left by a motor 31. A spindle 4 is moved upward and downward by a motor 47 and is rotated by a motor 50. A torch holding shaft 61 mounted to the bracket 62 at the bottom end of the spindle 4 is rotated by a motor 64. The torch advancing and retreating shfat 72 of a horizontal cylinder 7 provided at the bottom end of the shaft 61 is advanced or retreated by a motor 73 and the torch 6 of a torch holder 79 is tilted and turned by a motor 80. Each motor is detected and driven by the signal consisting of the above-mentioned combined pattern and the signal for the torch position by the detector, whereby automatic welding is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention i1. Regarding the creation of a welding method using a general-purpose welding robot p1 In the welding of large shipbuilding parts, automatic welding that can cope with the variety of parts and parts has been designed to increase its versatility, increase speed, and improve reliability. It is.

It is well known that among shipbuilders ζ1, welding work occupies a large portion. For this reason, there is a strong desire to improve manual or manual automatic welding by a large number of skilled welders, and to improve productivity and reduce costs by saving labor, automating, and increasing speed. In response to this, various types of automatic welding mechanisms have been proposed in the past, but they can be roughly divided into hydraulic systems and electrical systems. A representative example of these conventional systems is one that uses sensors to accurately position the torch relative to the object. The advantages of this are as follows: - The robot can store detailed information such as coordinates, posture, conditions, etc. up to L-L in advance. The aim is to simplify so-called teaching. Even so, it is inevitable that there will still be many difficulties in dealing with the diversification of shapes and dimensions of shipbuilding parts. Proposals for horizontal fillet robots for shipbuilding box-shaped parts equipped with binding or turning sensors, which are representative of electrical systems, are known.

2.Unfortunately, the biggest point is that it is for horizontal use and cannot be welded vertically. It is not a bad idea to keep it exclusively for the box-shaped part that is close to right angles, and in addition, separate equipment is required for its installation and movement, and it is necessary to deal with the diversification of the shape and size of the parts mentioned above. Although it can be called a robot with the versatility that makes it suitable for multiple uses, it should still be said to be a specialized robot.

Including such examples, the following points can be cited as common difficulties in various conventionally known robots. That is, 0) As mentioned above, even if some models are simplified, there are still difficulties in teaching. This type of teaching requires a lot of time when the object is a complex and diverse shape or large member, and it is difficult to ensure the required precision when working with a wide variety of small quantities such as shipbuilding parts. Almost impossible.

@ Many of the robots that have been proposed and put into practical use are semi-fixed types, and their operating range is at most 1.
．． It is about 5 m long, and should be said to be unsuitable for large parts used in complex shipbuilding.

0 As a shipbuilding department, its assembly accuracy, processing accuracy, delivery positioning accuracy, etc. are not reliable.

■ There is no proposal for a technologically complete robot for arc welding.

■ Lack of ability to adapt to expensive discounts.

I can point out various points such as: To put this simply, it is the assembly of shipbuilding parts in which stiffeners are attached to scallops and snips, and these cross each other and become obstacles to welding lines. It is obvious that there is still no proposal for a welding robot that can automatically weld and remove welds. This is the current situation, and the establishment of an effective and suitable mechanism and welding control process has been desired for a long time.

The present invention was developed to overcome the current situation, and its characteristics include the front and back of the welding robot (X
Jll + ) and left and right (ψ axis) can be freely moved as h1 function. + CZ axis) and its rotational movement (rp axis), as well as advancing and retracting the above 1 and - chi (R axis)
Enable tilt angle rotation (ψ axis) of the drawer l/-chi itself,
The basic idea is to perform rough control using the x, y, z, and P axes, and at the same time perform precise control using the R and ψ axes. The combined shape of parts and the corresponding welding procedure are taught to the IL calculator in advance, and during welding, the combined shape of parts is detected by at least two sensors, and this is used to form the pattern. In comparison with the combined shape, each control axis is actuated according to the sequence described above for the pattern according to the clever technique, and welding is automatically performed. With this 7'L, it is possible to weld automatically and with stable accuracy for nil fabrication of diversified shipbuilding parts.

Contributed to the invention! The basic mechanism of 'L' bathing robot is disclosed in Japanese Patent Application No. 51-121674 and Japanese Patent Application No. 51-12.
It was proposed as No. 1675, but here is an example of its configuration:
As shown in FIGS. 1 and 2. That is, the surface plate aυ arranged on the base (1), the welding robot support (16a) and (16b1), and then the rail (1) laid on this support
7a) and (x7b) are support mechanisms for a welding robot according to the present invention, in which a workpiece (one (11N)
and (1υ) are assembled. The basic form of the welding robot is made up of amazugirders (2a) and (2b), their girder legs (218,), (21d) and (21b), and (
210) is the mainframe (22a) and (22b)
(21a) - (21)))
The main frame has rail running wheels (29a) (2c+
b) (29c) (29d) and guide rollers (23a)-(23b) and (
23c) - (23d) are arranged. Furthermore, guide strips (24a) and (24b) are installed on each of the girders. The movement of the gate-shaped mechanism is carried out by a motor (25a) installed at the bottom of the sword leg.
) and (25+)), Binioff (26a) and (26
b), and a rack (27) fixedly installed along the rail.
a) and (27b) by means of a drive device.

As shown in this figure, the position detection device of the gate type mechanism @,
If (28a) and (28b) are attached, wheels (2
9a), (29b), (29c), and (29d), it is extremely easy to control the position of the portal mechanism between travel and stop (X-axis in the figure).

Next, the mechanism for moving the welding robot in the Y-axis direction is as follows. First, the movable trolley (3) moves along the guide strip (24a) -(
24b), this traverse (Yllllh) has motor (31), binion (32) - rank (33) and wheels (34a,) - (34a), (34b) - (
34b), (34c)-(34c), (34r-D
(34d) and (35a) - (35d), (35
b) (35c) (both of which are provided in contact with the upper, lower, and side surfaces of the guide strip).

As shown in the figure, a detector (36) is installed on this L5, and a wheel (
35a) and (35b) to control the movement and stop (Y axis) of the mobile cart.

Furthermore, the vertical movement (two axes) of the welding robot is based on the main shaft (4). This main shaft can rotate itself (W-axis) along with the above-mentioned vertical movement.The basic mechanism is as follows) ID
It is. That is, first, a connecting shaft holding cylinder (41) is disposed in the center of the movable cart, a shaft cylinder (42) is vertically inserted into this through a bearing (not shown), and the main shaft is inserted through this shaft cylinder. I
It is something to do. Next, place 71 at the bottom of -F of this shaft cylinder.
．． Square tubular vertical movement guide concentric with (43υ and (43b)
) are connected, and at the same time a carrier (4) is connected to the middle part of the shaft cylinder.
4] is fixedly installed. Further, one side of the main shaft has a rack for vertical movement (45), and the other side has a guide roller (not shown) mounted on the guide for vertical movement (45) held between the vertical movement guides.
6a) and (46b) are fixed 7. In such a mechanism, the driving device for vertical movement (two axes) of the main shaft consists of a motor (47) and a gear box (48), and this gear box has a Umemu rock structure (not shown) and a vinyl off attached to it. Built-in search. The vertical movement of the main shaft is performed by the above-mentioned vertical movement rack and this pinion, and at the same time, the second downward movement and stop (2Φ mountain) is controlled by the attached 7 The turning (VjIlη11) device is a motor (
It consists of a gear box (53) in which a gear mechanism (5])-(52) is installed, and the specific turning is performed by this gear (52) and the driving gear (44). The rotating and stopping (vI axis) is controlled by the intersecting detection mechanism (54) K.

The general-purpose welding robot used in the present invention is as described above.
The control system for each of the y, z, and F axes allows for accurate position control of the torch relative to the weld line. However, it goes without saying that the position must be further finely adjusted depending on the shape and dimensions of the welding member. Such fine adjustment is achieved by the mechanism described below.

In this case, the attached drawing shows a two-torch system, so! The details will be explained based on t.

Now, the torches (6a) and (6b) are
．． It is attached to the main shaft (4) by the bracket (62) via the torch holding shaft (6ta) and (aib).
However, this holding shaft is attached to the above-mentioned bracket with additional issue means (6
3) is rotatably held within a bearing sleeve (not shown in the drawings 1 - not shown). The rotation of the holding shaft (θ axis) is controlled by a motor (64
a) and (64b) and a gear box (65a) incorporating a gear V-machine Y (not shown) that engages with the holding shaft
) and (65b). For this iM connection, rotation detection mechanisms (66a) and (66b) are attached, and by this IL, accurate directional control for the welding line of 1 and 1 by rotating and stopping the holding shaft (θ axis) can be easily controlled. can do.

As mentioned above, once the torch has been correctly oriented to the welding line using the W and θ axes, it goes without saying that the distance between the tip of the torch and the welding line must reach a required level. Therefore, in the present invention, a mechanism for controlling the advance and retreat of the torch is provided.

That is, the holding shafts (61a) and (61b) and the torch (6
The connection mechanism with a) and (6b) is important, and its basic configuration is as follows. First, the torch holding shaft (61a
) and (61b), horizontal tubes (7a) and (7b) are fixedly installed at the lower ends thereof. Inside this is the torch drive shaft (71a) (7
1b) and the 1-chi advancement/retraction shaft (7mm) screwed together with this
(72b) is a gear box (75a) (75b) having a built-in gear mechanism (not shown).

Furthermore, a motor (73a) (7) connected to this gear mechanism
3b) and detection mechanisms (74a) (74b) are attached. In such a mechanism, the operation of the detection mechanism causes
It is easy to control the forward/backward movement and stop (R axis) of the torch via the torch forward/backward axis.

Next, the attitude of the torch, that is, the angle adjustment mechanism is as follows. That is, the torch holder (76a
) and (76b) are fixedly installed, and the torch rotation shaft (
77a) and (77b), this rotating gear mechanism (not shown) and a torch angle detection mechanism (for example, a synchronized control oscillator, etc.) interlocked with the rotating shaft (78a) and (
78b) is provided. Further, torches (6a) and (6b) are fixed to the rotation shaft via torch shafts (79a) and (79b). Motors (80a) and (80b) are connected to the torch holder and connected to the rotating shaft. In such a mechanism, the rotation of the torch is determined by the operation of the torch angle detection mechanism.
Stop (ψ axis) control is performed.

As mentioned above, X, Y, Z, '//, θ
, R, and ψ control axes make it possible to accurately control the direction and posture of the torch in response to changes in the welding line, making it easy to make the welding robot more versatile. In FIG. 3, the control axes mentioned above are extracted from FIGS. 1 and 2.

In addition to such a basic mechanism, the present invention also includes a scanning sensor as described later.

As mentioned earlier, the silk-touched fins of large shipbuilding parts come in a wide variety of shapes and dimensions, and exhibit various welding lines that can form a fixed part pattern. Time is well known.

If we were to talk about the shape of this type of raincoat and the moon determination,
First of all, it is known that there are two types of steel plates used as substrates: flat plates and curved plates. Next, there are so-called scallops and snips in the shape of the above-mentioned steel sheets used as concrete finishing parts, and stiffeners are added to these, which become obstacles to the weld line, and there are also differences in thickness. It shows the truly diverse shapes of silk stitching. - It goes without saying that in the construction of a ship, there are different combinations of parts depending on the type and purpose of the ship.

However, upon careful consideration, it was found that in the combination of eight smokes, these could be classified as patterns. The one in Figure 17 is an example of this, and is patterned into 6 types and 28 types of combinations of raincoats.
This is a typology. Of course, it goes without saying that there may be many variations in the combination pattern of such members. The present invention is based on patterning such a shape of a member combination, and the welding procedure for the shape pattern of the member combination L7 shown as an example in FIG. 17 above is taught on a computer in advance. and store it.

In the present invention, for the member combination shape pattern and the welding procedure therefor taught in advance in this way, in actual welding, the combination shape of the members is detected by at least two copying sensors, and this is converted into the pattern. Welding is automatically performed by comparing each pattern with the combined shape and controlling each control axis based on a welding procedure taught in advance for each pattern.

An example of the basic configuration of such a sensor for tracing control is shown in FIGS. 4 to 6. That is, the sensor (100) (a-b-C-d) is attached to its support shaft (
101a) and (101b) to the horizontal tube (78).
and (7b), and is arranged so that its anus is on the same plane as the torches (6a) and (6b). In this case, the connection mechanism between the sensor support shaft and the sensor is provided by cylinders (102a) (102b) and piston rods (103a) (103b). Such a sensor has its holder (XO4a) and (1
04b) to the piston rod, and inside the holder, as shown in FIG. ) Compatible sensor body (108)
(109), (110) and (111) are incorporated. This sensor body does not necessarily need to be a specific one; it may be a contact type such as a conventionally known differential transformer, or a non-contact type such as an eddy current sensor or a phototube. is possible.

Such a sensor is controlled in a position according to its type and performance by actuation of the cylinder.

In the present invention, the shape of the member is detected using at least two of these sensor mechanisms, but the sensor (10
0c) and (100d), and a sensor (100a toob) is used if necessary.

Here, the contents of the sensor tracing control as described above will be explained in detail in relation to each control axis. First, X.

Regarding each control axis of Y and T (and/or θ),
■Sensor leading method ■Sensor trailing method can be adopted.

The first is the sensor-advance method. In general, the sensor advance method is well known, but upon examining its actual nature, it turns out that it is simply an on/off control system, which suffers from positional errors due to time lag, etc., and is inferior in accuracy. The present invention is an improvement on such RIG points, and in order to avoid complexity, the etorchi type function will be described and representative thereof. In the case of this one-to-one type, the i17 control axes e, X, Y, and F axes participate in the control system of the sensor that is actually tracing the wall surface. Now, Fig. 12 shows the copying control mechanism using the upper R+2 sensor as a block, which was extracted from their Figs. 7, 8, and 9. be. The important thing here is that the distance between the preceding sensor and the torch is always constant. The second is that the current value (position) of the sensor and torch is detected at a certain interval (for example, 0.5 mm as mentioned earlier).
1 sec is one example). Such current values, that is, as seen in FIG. 12 above, the analog detected by the sensor on the wall (150): 1ff (151) and the same toe are entered into the calculator (120) at the above-mentioned fixed intervals, and are calculated here. The control mechanism (1
26) Here, the control axes are controlled as specific analog quantities. This allows the torch to be accurately positioned relative to the weld line without reducing the welding speed. Now, let's temporarily fix the distance between the sensor and the torch to 5 crn, and set the above detection interval to I.
To make CIn, 18e (! binding, and minute) easier,
If we take as an example one-axis copying with only the X-axis, the block shown in FIG. 13 will be obtained as a copying system of a sensor and a torch. Therefore, in the initial state of copying, the sensor is located at the point marked 5 in the figure 1, and approximately 1.2 seconds after this point it passes the point 6 crn.

At this time, the current value of the sensor ((151) in Figure 12)
is read into the divider, while the current value of the torch (same <
(152) ) also enters the il force 9 machine at the same time, is calculated here, and is output as the command value (same < (153) ) tL
Ru. This command value (153) controls the control axis (130) and determines the position of the torch. In this way, command values are issued while reading data at regular intervals, and welding progresses accordingly. If the copying system shown in Fig. 13 were to be combined into one algorithm, the flowchart shown in Fig. 14 would be trivial! ) can be done. This is similar to the one in Fig. 13 of fi12 above, and we temporarily add one rotation of the loose shown in Fig. 14 to 1 second.
It belongs to C. This value can be set as appropriate based on the required welding speed and other factors as one of the hardware items in the computer (12(+)).
5) is the capture of the current values of the torch and sensor 9-,
This output is (151) and (152) in Figure 12.
That's a total of n machines. (156) is the 1714 machine output as a command value, and (153) in FIG. 12 is a trick. (157) is the following D K ! of the actual traveling distance.
-1 calculation, and the judgment as to whether this traveling distance exceeds 1 Crn is made in (158), and if it is less than 1 cyn, no new sampling points are calculated.

If it exceeds 1 crn, the next new sample point is the first point in the calculation.
Then, it is stored in a total of n machines. This step is indicated as (159). To explain this kind of loop more specifically, in the first second, the torch and sensor are 8
It will go on for a while. Since the sample points have a period of 1 second, there is no need to newly subtract and store them here.

After 2 seconds, it has progressed by about 1.8 cm from the initial state. Here, N1 is calculated by interpolating the wall surface coordinates at the point ICrn and the coordinate value at 1.8 cm, and is stored. This note will be used as a command value after 6 seconds. After 3 seconds, the vehicle will have traveled 2.8 squares, so the coordinates at point 21T771 will be found in the same way. In this case, the above interpolation means that the first
Considering the sample points in Figure 3 ■, the j zapura of tsuzu (r) is already known, and this relationship is Φ)4−m=−1rrn−1−−1→■・--Ikkoichi-
-----i
(XS, YS). After 2 seconds, the sample point (SX, SY) of ■ has advanced by about 1.8 rrrm from the point of ■2 (since ~), the sample point (SX, SY) of t'! (
xs, ys), as shown in Figure 15, if the reference coordinates of the sensor are (P, Q) and the minute displacement of the sensor is ■, then XS = P - a sin W YS = Q0a cosV ' can be easily calculated. In this way, automatic welding can be easily carried out by sequentially detecting and calculating the coordinates of the 1L distance at regular intervals and accurately positioning the torch by the subtractor until the welding is completed.

Next is the sensor trailing method. In this case, contrary to the preceding method, a sensor is fixedly installed behind the torch at a certain distance.

FIG. 16 shows the copying process using such a torch sensor system. In the figure, the algorithm regarding the movement of the torch and sensor connecting each point schematically shown is as follows.

First, point ■ in the figure: In this initial state, it is assumed that the position of the torch is deviated from the standard by [stock]).

Point ①: Since the sampling or detection period (d) is determined as mentioned above, calculate the above ① and ①, and V
Proceed by modifying / as much as possible.

(Point ■: After progressing by @ through the above steps, overcome the deviation @ above again) and proceed.

Point ■: This is an example when the wall rN+ is curved.
7, first check the displacement ladder from the virtual v1 ■ surface at this point.

■ Point: At the same time, when the next MiJ record ■ minutes have progressed, Sat n1
2 so that it intersects with the virtual wall surface Av (α + β 9 minutes V no F
Correct.

Point (■): Here, repeat the same operation as in (■) above.

Using this algorithm, it is possible to accurately determine the A position of 1 and 1 without any problem even if the sensor follows the method, and it is possible to weld correctly. In this case, the control block dl for the trailing method is similar to that shown in FIG. 12 described above, and its operation is performed as follows. That is, in FIG. 16 above, α”jan(
-), but here, the traveling distance t in L2 unit time: the value one cycle before t This 1.1 is determined by the sensor in Fig. 12.
151). In this case, the above is calculated by the following formula. That is, here, M and V are the current values of the torch mentioned in connection with FIG. This is the general information. That is, ΔX = L cos V' ΔY = L 1lIin F . With such command values, the torch can be controlled accurately and easily.

Each of the control axes of X, Y, W and/or θ is appropriately controlled by the sensor, and the position of the torch can be easily adjusted. This is sufficient for normal parts assembly and welding. However, due to force, when assembling large components for shipbuilding, as mentioned earlier, the shapes and dimensions of the components vary widely.
It is well known that it is not possible to stick to a fixed part pattern, but to show various welding lines! 3. Therefore, in the present invention, in order to exhibit fine adjustment and sufficient adaptability that can correspond to these member patterns, we have further added a centric tracing system for the R-axis and ψ-axis. This is what I entered.

To! +1. As mentioned above, the present invention patterns the shape of the combination of members, but it goes without saying that the combination pattern of such members should have many variations. In the case of automatic welding, it is difficult to cope with the system using only the control axes of x, y, z, and T (in addition, θ in the case of a two-torque system) as described above. This is because the above-mentioned axes of a welding robot for assembling large parts are inevitably large and heavy, so the time constant is also large, and the robot mechanism used in the present invention for grasping the current value of each axis is This is because the response is not necessarily fast in nature. Invention V? This is the reason why R and ψ control axes are further provided on the W (or θ) axis for fine adjustment in order to deal with such a shape. Such x, y, z, qt (or θ).

In order to organically and effectively operate the R and ψ control axes using the sensor copying mechanism, it is necessary to date and store in advance a member pattern such as the one shown in FIG. 17 above in a computer. . This allows the welding robot to freely and automatically weld any combination of shapes.

Figure 18 (ai and (bl) shows a suitable sensor and torch arrangement on a tube for sensing the end of such a member and its shape (i.e. as shown in Figure 17). This is an example showing the relationship.The example shown here is IJ,
The basic configuration is the same as that described above in detail in Figures 4 to 6 and related to this machine, but the one in Figure 18 achieves tracing control by the R axis including the ψ axis. This mechanism is particularly suitable for this purpose. That is, in the figure, A indicates a differential transformer type sensor, and B indicates an eddy current type or LC type magnetic sensor. This is the basic configuration, and in addition to these, C and D, which are also differential transformer types, may be added as necessary.
A sensor is attached.

Looking at the role that the magnetic sensor should play, firstly, the magnetic sensor B can detect changes in the end of the member as shown in the member pattern in Fig. 17 as a surface, and this allows it to be This is because it is advantageous. This is why the A sensor is of a differential transformer type.
By making NC fine adjustment of the axis possible. What is most important in the construction and arrangement of the A and B-tn sensors is that they always maintain a constant spacing and height in relation to the torch.

If both sensors are moved simultaneously in this relationship, it is possible to detect changes in the ends and shape of the member as shown in FIG. 17 described above, and to perform NC fine adjustment based on this mainly on the R axis.

In this case, there is no need for any special functions for the two sensors. An ON-OFF function that simply knows the starting point and ending point of the shape change in the direction of movement is sufficient. It was confirmed that all of the change patterns shown in FIG. 17 can be covered by the ON-OFF changes and combinations of A as a differential transformer and the eight sensors as magnetic sensors.

The trick is to know the patterns of changes in the shapes of all parts based on the ON-OFF changes and combinations of the A and 8 sensors, which are always kept at constant intervals and heights in relation to the torch. First, the 17th
The reason why we said that the basic change pattern shown in the figure should be taught to the computer in advance is to teach this n as a combination of such ON-OFF changes. By doing this, the machine immediately issues the necessary commands to each control axis, mainly the xtill, and facilitates automatic welding that immediately responds to changes in shape. 71
is the basic tracing control using the R axis.

When assembling and welding specific members, as shown in FIG. 17, it is normal for there to be many obstacles (such as stiffeners, etc.) in the welding direction.

In such a case, use only the A and 8 sensors mentioned above.
It will be difficult to pinpoint this. The sensor for this purpose, shown as C in FIG. 18 above, is part 7L. Talented 1. Similarly to the A% 8 sensor, Qi is ON -O.
Only the FF' function is sufficient, but in short, +i1shi A%B and U
By changing the ON-OFF state of the three sensors of C and combining them, it is possible to respond to all changes in the shape of the evacuation, including obstacles. Furthermore, installing the old D sensor L7 shown in Fig. 18 to maintain the height at a constant level can be said to be a perfect solution.

The above shown in FIG. 18 is an example of its basic configuration, and it goes without saying that other sensors should be provided as necessary.

What is important is to pattern the changes in the assembled shape of the parts and arrange the necessary number of sensors that can detect them accordingly. In this case, the arrangement order of each sensor, especially the A and 8 sensors, can be determined as appropriate depending on the specific member shape pattern.

Now, the mechanism of welding low hot mentioned above and this
Automatic welding of simple horizontal and vertical welding lines is easy with the K control system, although there are some difficulties. However, when assembling a concrete table for a large scale shipbuilding vessel, it is normal to have a part I shape as shown in FIG. 17 above.21. Ru.

Regarding the detection of the shape of such a member itself, it was proposed in Japanese Patent Application No. 145552/1983, and based on this, it is necessary to pattern the end portion and its shape and teach it to the mechanical device in advance. Detected by the above-mentioned special request Akira! As described above, by comparing the shape and the contents of this teaching, necessary commands should be issued to each control axis, mainly the R axis. By using such a control system, the following problems can be easily realized in welding, which had previously been considered difficult or impossible to automate. That is, ■ Corner processing (first
Figure 9-a) ■Weaving process (same-b) ■Turning process (same-C) ■Welding line misalignment treatment (same-d) ■Start and end locations f! f4 (same 〇) ■Multi-layer processing (same - f) ■Gap variation treatment ■Processing with different plate thicknesses, etc.

The welding robot according to the present invention can detect the shape of the welding member and the welding line from time to time using the attached sensor. X, Y' mentioned earlier in response to the trh information detected by this n.

Commands are given to each of the Z, F, θ, R, and ψ control axes, and the position and orientation of the torch can be freely controlled and determined. A suitable computer is provided to process such various detected information. Such a control mechanism enables simultaneous control of each control axis, and is not only versatile, but also facilitates numerical control (NC) by using an NC-servo mechanism.

Next, examples of the construction of a control system for each of the above control axes are shown in FIGS. 7 to 9. The one in Figure 7 is a conceptual block, the one in Figure 8 is a basic block for each of the control axes, and the one in Figure 9 is a block mainly centered on the interface in each of the above figures.

In the figure, (120) is an electronic computer, (121) is its input/output device, (122) is an interface, (123) is an arithmetic control circuit, and (124) is a digital-analog (D/A
A) converter, (125) is synchro-digital (S
/D) or a code converter and its amplifier, (126)
is the motor control device for the control axis, (127) is the tacho generator, (128) is the control motor, (129) is the pulse generator or synchro oscillator, (130) is each control axis, (122Xv) is the welding machine interface , (1
40) is a power source for a welding machine, (141) is a welding machine control device,
(142) is a wire supply device for welding machines, symbol (TG)
) is the tacho generator, (PG) is the pulse generator, (
DH) is an absolute value type pulse generator, (CX) is a synchro oscillator, (, 5I) is a synchro-digital converter, R is the right side, and L is the left side. Other numbers are the same as in each of the figures above.

The most important thing in controlling the welding robot using the above control system is to accurately position the torch at the welding line by 16". To do this, at the necessary welding speed,
It is necessary to position and control the speed of each axis of the front M12. Therefore, the motor mechanisms for controlling each axis shown in FIGS. 7 and 8 are all based on the NC-servo control system. However, when applying the above control system to a specific welding robot, it is preferable to take careful consideration.

This is because the operating time constants of each control axis are slightly different. This is because the main object of the welding according to the present invention is automatic welding of large parts for shipbuilding. From this point of view, FIG. 9 shows an example of the interface circuit shown as (122) in the control system shown in FIGS. 7 and 8 above.

First, FIG. 9-(a) shows a control system centered on interfaces for the R-axis and ψ-axis among the control axes described above. The R-axis and ψ-axis are the welding robot 1.
Since it is the smallest among the control axes, and its operating distance/rotation speed is extremely small, a normal absolute control system is adopted for its control system.

As mentioned above, this control system is characterized by the synchronized oscillator (129a) generated by the rotation of the motor because it precisely controls the position and orientation of the torch with respect to the welding line. This output is converted into a digital number by the S/D converter shown as (125a), and the output from the computer (1, 35) and the arithmetic controller (123) are converted into digital numbers. This output is converted into an analog quantity by the 1)/A converter (124), and is introduced into the motor control device to control each control axis.

Next, the above (Figure b1 shows the side part 1 with respect to the T axis and the θ axis.
No system shown. The v/#1 and θ-axes are the basis of the R-axis and ψ-axis as mentioned above, but since both are rotating axes, the absolute method is sufficient as above. Confirmed. In this case, the difference from the control system for the R-axis and ψ-axis is that the synchronized oscillator is replaced with an absolute pulse generator (129b), and therefore the S/'D converter is replaced by a normal code converter (129b).
5b). This control function is
There is basically no difference from those for the it axis and the ψ axis.

Furthermore, it is preferable that the X, Y, and two axes be arranged differently from the other axes by ld. This is the f of each axis mentioned earlier.
The moving distances of the y, This is because the configuration of the control device accompanying this is not easy. Therefore, in this configuration example, incremental,
That is, based on the incremental method, the absolute value method described above is used for direct control. The reason why the incremental-absolute value combined method is used is that if only the incremental method is used, for example, when there is a malfunction such as a miscount in the control device, this will accumulate and cause a large error. If the above-mentioned combine harvester method is used, the advantages of the incremental method in terms of programming and simplification of the control device, as well as the ease of converting programs and the ease of starting and restarting operations in the middle of the day in the absolute value method, can be achieved. I can do it. An example of such an incremental-absolute value combination method is the control system shown in FIG. 9-(c). In the same figure, block names other than those mentioned above are (1
31) is a current value absolute value circuit using a pulse generator (129c), (132) is a residual counter that ticks the current value,
(133) is an adder, and (1, 34) is an increment counter for the current value.

Generally, in a servo mechanism, it is normal that a target value and an actual value do not necessarily match. FIG. 1() shows this as one schematic pattern. If a deviation as shown in the figure occurs, at the required speed,
It would be difficult to weld automatically. It goes without saying that such tactics should be compensated for by any number of means. This is another reason why we adopted the incremental-absolute value coupling method in the control system for the X, Y, and Z axes in this configuration example. Positioning and speed control determine the automatic welding, and for this reason, it is preferable to use an NC servo mechanism for each of the axes mentioned above, as mentioned earlier.

For example, in the case of a single axis, the position command for every 0.5 w is 5
It is a position control system that outputs every 0 m 86c. The welding speed at this time will be 600 ttan/min. Therefore, the welding speed can be controlled by changing the above-mentioned 507πsec. Under such conditions, in the case of two axes, position commands of (0,5 cos θ) in the X direction and (0,5 sin θ) in the Y direction are issued. This is the above-mentioned incremental method, and its basic form is shown in FIG. That is, the respective places fA, PtP!
. . . is represented by (ΔX!-ΔYl).

In the present invention, the current value based on such an incremental method is
The counter shown as (134) in Fig.
In 2), the difference between the current value and the target value is calculated n, and this value is used as the command output of the computer (1, 20) by the absolute value counter (131) at that time and the adder (133).
is added. This added value is equal to the specific command value by 1.7 and is adjusted by the command counter (135), f'L, and the subtractor (
123), the previously calculated increment value is subtracted, and D/
In the A converter (124), the analog is the best. This is the control amount of the motor (128). At this time, the output t of the command value counter (135) is simultaneously input to the Zensen counter (132), and the detected current value ((XZ(+C)
After comparing with the pa output of ), the difference is the difference between I'm sad. In this way, as mentioned earlier, the control amount is issued in the form of (Ji1 command) at every foot interval, and each control axis of X, Y, and 2 is accurately controlled. In other words, the control system suppresses the drawbacks of the above-mentioned incremental and absolute value methods and makes effective use of their advantages.

The following table schematically shows the functions of this control system under normal conditions. Here, the values described above as an example were taken for both the distance axis and the time axis.

(Detection interval = 1 = 0.5 m5, t = 50 m5
ec) The functions shown in the table above are predetermined for both the time and distance axes! Continued for an interval of t
, the required welding speed is easily possible.

Next, a concrete implementation procedure of the present invention will be explained.

Information to be taught in the present invention can be broadly classified as follows. That is.

■ Member coordinates ■ Member pattern ■ Leg length ■ Number of repetitions is n. These pieces of information are stored one electronic word per poem after a code is set using various switches on the pendant, for example. Of these, first of all, if we talk about the member coordinates, the teaching point of the Partou coordinates, which is the starting point of welding, can be arbitrarily selected. However, from the viewpoint of effectively operating the welding robot and increasing the efficiency of the welding work involved, there is an optimal member coordinate teaching point. Such an xyz system zagura teaching point is determined by the specific 14th component of the surface pattern described below.

The component pattern begins with how to place the parts.

The first way to place it is to align the longitudinal direction of the paulownia with the X-axis direction. Next, the movement of the welding robot is x-
One block is made up of materials that can be moved in one direction in each of the y and z directions without intersecting each other, that is, in a so-called sweeping motion. If this is done, the teaching point of the member coordinates will only need to be one per block, and the welding efficiency of the welding robot will be dramatically increased. As described above, the selection of component patterns and the structure of blocks are major factors that affect the efficiency of welding robots, but the pattern of component shapes as shown in FIG. memorized in the computer.

Now, the welding order is set for the patterned component blocks as described above. This sequence involves the previously described shape detection system for the patterned component configuration and various arithmetic circuits in the control system based on this, but an order that does not follow the basic sequence may be necessary for the component configuration. In this case, the member coordinates must be taught again. In any case, similar to the structure of the above member pattern, the movement of the welding robot is
It is important to take care that the two sides do not intersect and run in one direction.

In the welding sequence for the above-mentioned member pattern and this part, the same pattern group appears repeatedly. In such a case, it is not necessary to teach all the patterns one by one. It is sufficient to simply teach the number of repetitions of this to the reference pattern.

Such a repeating pattern can be arbitrarily determined. However, in order to improve the efficiency of the welding robot from the outside, it would be preferable to predetermine it in advance, for example, to prevent inconsistency in operation intentions and to ensure uniformity of the surface pattern.

Leg length is associated with all welding work patterns. Such leg length can be selected arbitrarily. Generally, when the leg length is updated in the above teaching procedure, this leg length is normally used for all subsequent work patterns until the next new leg length is entered.

This is no exception even when the leg length is updated in the above repeating pattern. In this way, the pattern is made so that both the horizontal leg length and the vertical leg length are constant21. A member block should be constructed.

The detailed teaching procedure detailed above will be omitted, but the mechanism of the welding robot that has been described so far is similar to the control system that has also been described in detail. can operate very specifically. If all the functions of the welding robot according to the present invention are summarized from the beginning to the end point, the second
It is expressed as shown in Figure 0. To elaborate further on this,
First, the above r start 1jb J'd is a function to start the welding work by the welding robot. The next step is to input the prepared system program and monitor program into the computer, perform initial settings for welding work, check whether each power source is turned on, and place the computer in a so-called standby state. The next "reference" is a function to check the currently registered work. At the same time, the operation sequence within one welding operation and its status word are also referred to.

All of this can be confirmed from the data displayed on a suitable display panel.The "teaching" function is a function from inputting data to its knitting percentage. This comes from the following: That is, first, the torch actuator is moved to the member coordinate point mentioned above. Next, the welding work position is confirmed using a sensor, and the member information and welding conditions are stored in the computer. , further repeating this data
Edited so that it can be welded and moved by this,
It has been modified so that data can be deleted, changed, and added as necessary. The above-mentioned "teaching" function comprehensively performs such contents.

Now, next, the above-mentioned teaching contents are executed without welding, and there is no confirmation whether the welding robot operates or not without welding. The trick is the "test" function, which includes the robot's horizontal movement, vertical movement, corner movement, and additional movement as necessary.

Y + z + W This is done for each control axis of rθ and Jψ. This means that the welding robot is fully prepared. Next, the welding robot starts a specific welding operation according to the above-mentioned teaching contents.The entire control system including the welding operation at that time is the same as shown in FIG. 8, but the welding itself is horizontal welding, Vertical welds, corner welds, and special welds such as those described in detail are made in sequence according to the sequences previously taught. When welding of the in-house blocks is completed in this way, the welding robot returns to its original position.

As detailed above, according to the present invention, it is literally possible for the first time to perform welding using a general-purpose welding robot, and it is possible to perform welding using a large-scale welding robot such as one used for shipbuilding, and the surface shape of the welding robot is diversified. It is possible to effectively deal with such member configurations. The actual benefits from this are truly large, and the efficiency and labor savings of the welding work mentioned above can be said to be immeasurable.

[Brief explanation of the drawing]

FIG. 1 shows one embodiment of the welding robot of the present invention.
The front view of the torch method, Figure 2 is also its side view, and Figure 3 is the front view of the torch method.
The figure is an explanatory diagram of the control system in Fig. 1, and Fig. 4 is an explanatory diagram of the control system in Fig. 1.
1) A front view showing the arrangement of the sensor, torch, and torch advance/retreat axis in Fig. 1, Fig. 5 a side view thereof, and Fig. 6 showing an example of the sensor arrangement according to Fig. 4. 7 is a block diagram showing the outline of the control system according to the present invention, and FIG. 8 is a block diagram showing the outline of the control system according to the present invention.
Block diagram, FIG. 9-(a) is a control block diagram using the II and ψ axis absolute value method in FIG. 3, and bl is a control block diagram using the T and θ axis absolute value method, same <
(c) is a block diagram of one block diagram of the system using the combination of the incremental value method and the absolute value method for the X, Y, and z axes. The figure is a block diagram showing an example of a control system based on the sensor advance method, FIG.
N! The is diagram also calculates the wall surface coordinates using the sensor 1
An explanatory diagram showing an example, Fig. 16 is an explanatory diagram of the sensor trailing method, gal 7 is an explanatory diagram showing an example of patterning the welded part assembly shape, Fig. 18-ton detects the shape in Fig. 17 Fig. 19 is an explanatory diagram showing an example of special welding using the R and ψ axes in Fig. 3, and Fig. 20 is a longitudinal sectional front view of the sensor arrangement according to the present invention. FIG. 2 is a block diagram of all functions performed by a welding robot. In the figure, (1) is the base, 01) is the surface plate, 010 of α and θ
0 is the welding part, (16a) and (16b) are the supports for the welding robot, and (17a) and (17b) are the rails. (2a) and (2b) are garters, (21a) (21
b) (21c) and (21d) are girder support legs, (21c) and (21d) are girder support legs;
22a) and (22b) are mainframes, (23a)
(23b) (23c) and (23d) are guide rollers, (24a) and (24b) are guide strips, (25a) and (251)) are motors, (26a) and (2Gb)
is a binion, (27a) and (27b) are racks, (2
8a) and (28b) are position detection devices, (29a) (
29b) (29c) and (2C+a) are wheels. (3) is a moving trolley, (31) is a motor, (32) is a pinion, (33) is a rack, (34a),
(341)) -(34b), (34c) -(34
c) and (34d) - (34d) are drive devices, (3s
a) and (35b) are wheels, and (36) is a detector. (4) is the main shaft, (41] is its holding cylinder, (42) is the axis, (43a) and (43b) are the vertical movement kite, (44)
is a gear, (45) is a vertically movable rack, (46a) and (
46b) is the name - meat strip, (47] is the motor, (48) is the gear box s (49) is the detection tag'& structure, (50)
) is the spindle rotation motor, (51) (52) is the gear mechanism, (53) is the gear hook, (54a) (54
b,) is a detector! +'! . (6) (6a) and (61)) are torches, (61a)
and (61b) are long-sleeved torch retainers, (62) are brackets, (63) are supplementary means, (64a) and (64b) are motors, (65a) and (6sb) are gear boxes,
(r6a) and (66b) are rotation detection techniques. (7a) and (7b) are horizontal tubes, (71a) and (71b)
) is the torch overtime axis, (72a) and (72b) are the tow forward and backward axes, (73a) and (73b) are the motor, (74
a) and (74b) are detection mechanisms, (75a) and (75
b) is a gear box, (76a) and (76b) are torch holders, (77a) and (77b) are torch rotation shafts, (78a) and (78b) are torch angle detection mechanisms,
(79a) and (79b) are the torch shafts, (80a) and (sob) are the motors. (100) (a-”b-c d) is the sensor, (
101a) and (101b) are their support shafts, (102a)
) and (102b) are cylinders, (103a) and (
103b) is a piston rond, (104a) and (1
04b) is the sensor holder, (105) (106)
and (107) are the sensitive surfaces of the x, y, and z axes, respectively, (
ios) (109) (110) (111) is the main body of the sensor. (120) is an electronic computer, (121) is an input/output device,
(122) is an interface, (123) is an arithmetic control circuit, (12 is a D/A converter, (125) is an S/D or code converter, (126) is a motor control device for control axis, (127) is a tacho generator, (128) is a motor, (129) is a pulse or synchro oscillator, (13
0) is each control axis, (13υ is the absolute value circuit of the current value, (1
32) is a residual counter for the current value, (133) is an adder, (134) is an increment counter, (135) is a command value counter, and (136) is each control shaft gear mechanism. (140) is a power supply for the welding machine, (141) is a welding machine control device, and (142) is a welding machine wire supply device. (150) is the wall surface, (151) is the detected analog amount, (1
52) is the detected digital quantity, (153) is the command value, (15
5) is the capture of the current value, (156) is the output as a command value, (157) is the calculation of the traveling distance, (158) is the judgment of the distance, and (159) is the input to the calculator. Patent applicant: Nippon Doppan Co., Ltd. Inventor: Hiroshi Nomura
Yuji Sugitani
1) Yoshitaka Sakanobu
Yoshi 1) Ritoshi Take
Masa Inoko Kunido
Written by Shindou Minato
Hiroshi Eiji
No Hiroshi Sokuma Hori
Ken Kuchi Diagram 3 Z-axis ■ 465- (b) #! Figure 6 (C) 1U Figure 12 * Figure 13 469- Figure 14 ta Figure 19 (A) (B) (D) (E) 471- (C) (F)

Claims (1)

[Claims] The welding robot can freely move rearward (X-axis) and left/right (Y-axis), and the sensor installed on it and the main shaft for holding the torch can freely move up and down (Z-axis) and rotate (q-axis).
This is a mechanism that makes it possible to move the torch forward and backward (IT axis) and to rotate the inclination of the torch itself (ψ axis). The welding shape is patterned, and the welding procedure corresponding to the patterned part-side joining shape and this welding is taught to the IL calculator in advance.1
In the welding process, the combined shape of the part is detected by at least two hinges and compared with the fourth combined shape of the part patterned in Section 011, as described above by J. An automatic welding method using a general-purpose welding robot 1, characterized in that each of the control axes is actuated to automatically weld according to the sequence for the pattern.