JPS5827076B2 - The actual actuator no. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention allows a tool having directional workability, such as a welding gun or a painting gun, to be correctly directed at a linear corner, thereby accurately and uniformly performing various operations at the corner. The present invention relates to an automatic corner pointing device for a directional actuator that can be processed to

In the frame assembly process in the construction industry and the hull frame assembly process in shipbuilding factories, various processing operations are often performed at corners where two planes intersect, and recent advances in welding technology have made it easier to replace conventional rivet processing. Instead, the current situation is that most of the connections are made by welding means.

Particularly in the shipbuilding industry, where there are many opportunities to build large ships such as tankers in the tens of 317 class, it is natural that the number of welding points increases both in quality and quantity, and it is important to rely on manual labor for this welding. It is well known that automatic welding work is gradually being actively introduced in various fields, as there are undesirable problems such as long construction periods, increased labor costs, soaring ship prices, and delayed delivery dates. It is.

Now, if we consider the case where the hull frame is assembled by welding, the hull is once assembled into divided blocks and then joined together on the dock, but at that time, the lodge members and transformer members are directly attached. The method is to weld the skin plate and upper deck to the outer circumference of the cross-assembled parts, and the work of linearly welding the inner and outer parts of the orthogonal parts, that is, the welding work in the garden, is particularly important. be.

This fillet welding is difficult to work with when automating welding, and the weld metal is usually raised higher than the base metal surface so that the cross section forms a right-angled isosceles triangle at the inner heel. If it takes on the shape of a right scalene triangle, the strength will be extremely reduced and various problems such as peeling of welded parts will occur after delivery to the ship.

However, finishing the build-up into a right-angled isosceles triangular shape is a difficult task even for highly skilled workers as it requires the correct facing angle of the welding gun. It is even more difficult to do so, as fully automatic fillet welding equipment that can meet the conventional demands has not been provided, and we still rely on semi-automated equipment that requires supervision by skilled personnel. The current situation is that

In this way, even if we take a single automatic welding device, a mechanism to accurately orient the welding arm as an actuator with directional workability to the corner has not yet been developed, so it is difficult to fully automate it. It is well known that an automatic processing device that can achieve this has not yet appeared in each processing industry, and in view of these points, the present invention aims to provide a directional actuator that correctly points the target corner ridgeline. This invention was invented as a result of various researches, and its features are clarified by the following explanation based on the attached drawings. FIG. 1 is a perspective view of the main body of an electric welding robot 1 according to an embodiment of the device of the present invention, in which a base is placed on a guide mechanism such as a rail and moved to a desired position. a base 2; a base shaft 3 which is pivotally supported on the base 2, stands in a direction parallel to the ridgeline of a corner 26 (described later), that is, in this example, in a vertical direction, and is expandable and retractable in the direction;
An arm 5 is installed horizontally in a direction perpendicular to the base shaft 3 (horizontal direction in this example), and is extendable and retractable in the axial direction Y and can be moved around on a horizontal plane. A welding shaft 4 serving as an actuator is provided with a welding gun 6 oriented toward the shaft end, and a welding shaft 4 is arranged parallel to the welding shaft 4 above the welding shaft 4, and is parallel to the welding shaft 4. A sensor 16 for corner detection is attached to the tip of the shaft 15, which is extendable and retractable.
and a corner detection body 14 which is pivoted so as to be able to travel parallel to the travel of the shaft 15, and the arm 5 is further configured by a rotation-linear reciprocating motion conversion mechanism using an electric motor 10 as a drive source. Parallel movement can be performed in the direction X perpendicular to the axial direction Y.

The welding robot 1 having the above-mentioned skeleton structure has a linear corner 26 formed by two flat plates 25° 25 that intersect at a predetermined intersecting angle θ1, for example, at a right angle, and are arranged to have a common orthogonal cross-horizontal plane. After the base 2 is moved to a nearby position, the base shaft 3 is extended, and the welding arm 5 is extended and contracted.
By performing a compound movement of travel R and parallel movement X, the welding gun 6 at the tip is brought close from an appropriate approach direction such as the direction of the equidistant line of the intersection angle θ1, and the welding gun 6 is used to Under electric welding, said corner 26
can perform welding.

In addition, in the case where there is only one welding gun 6, an appropriate drive mechanism 13 is used to swing the welding gun 6 horizontally at a eugenic angle, and
In the case of two or more units, it is sufficient to fix them in parallel with a slight pitch, and by shortening the operation of the base shaft 3, the corners 2
Welding can be performed sequentially along the ridge line 27 of No. 6 from above to below.

Contact type length measuring instruments 7-1 and 7-2 are mounted on both slightly rear ends of the welding gun 6 at the tip of the welding shaft 4.
It is provided so as to protrude at a predetermined angle between the
In this example, the welding shaft 4 is extended in the horizontal direction so as to be included in the plane of movement of the welding shaft 4 which performs two-dimensional movements of , parallel movement X and rotation R.

The contact type length measuring devices 7-1 and 7-2 are capable of emitting electrical signals having positive and negative polarities corresponding to the position of the sensitive end when the sensitive end is mechanically displaced with respect to the reference position. If so, each type of length measuring mechanism can be used,
In this example, a differential transformer is used so that displacement of the movable iron core appears as a change in terminal voltage.

And the angle formed by the axes of both length measuring devices 7-1, 7-2 and the corner 2
The sum of the intersection angle θ1 of
90°-θ, /2).

On the other hand, the sensor 16 provided in the corner detector 14 detects the corner 2
There are various types of converters, such as a light amount-to-electricity converter that can detect the ridge line 27 of 6 as a difference in brightness from other parts and convert it into an electrical signal, and an air-to-electricity converter that can detect a change in pressure. In this example, a contact type sensor is used, and its structure consists of each of the isosceles triangular substrates 17, which are pivotably pivoted at the center of the base at the tip of the arm 15. Rollers 18 are rotatably attached to each corner,
A roller 18 which is pivoted at the apex corner of the arms is resiliently supported by balance springs 20 so as to be held at the leading edge of the arm 15 in a normal state where no mechanical force is applied. Touch switches 19° 19 such as micro switches are respectively attached to the arm 15 in a line symmetrical manner, and when the flat plate contacts the tip roller 18 and the side rollers 18 tangentially, the touch The switches 19, 19 are operated by switching from on to off.

This corner detection body 14 is further fixed with a declination signal generator 21 in the vicinity of the travel axis with the welding axis 4 as a reference line, and in this example, a potentiometer is used as an element, The deflection angle with respect to the axis 4 can be converted into an electric signal having positive and negative polarities, and the resistance value is formed to change in relation to the movement of the detection body 14.

The configuration of each part of the welding robot 1 is as described above,
And a length measuring device? -1 and 7-2 are connected to a drive source 9 for extending and retracting the welding arm 5 via a drive system, and both length measuring devices 7-1 and 7-2 are drives for moving the welding arm 5 in parallel. The deflection signal generator 21 is also connected via a drive system to a drive source 8 for the rotation of the arm 5, so that the robot 1 can be automatically controlled in the working direction of the actuator to the corner 26. It is formed so that it can be operated so that it can be directed to.

Next, the operation of the welding robot 1 will be explained with reference to FIGS. 1 and 2 and FIG. 3 showing the operation procedure. The welding robot 1 is moved 31 in advance to an appropriate position in the vicinity of the corner 26 to be welded. The base 2 is first fixed, and then the welding work is automatically controlled by automatic open detection. At this point, the corner detection body 14 and the welding shaft 4 are
It goes without saying that it is necessary to roughly face the corner 26 so as not to face the corner 6.

When the positioning of the base 2 is completed and the base 2 is stopped 32, a start command is issued, and the detection shaft 14 is moved forward 33 by sending compressed air at a predetermined pressure to the arm 15, for example, a pneumatic cylinder.

Note that this pneumatic cylinder 15 is designed so that the pressure inside the cylinder can always be maintained at the predetermined pressure regardless of the presence or absence of external pressure by means of a relief valve or the like provided in the pneumatic line.

In this way, the tip of the corner detector 14 advances toward the corner 26, but in this case, the shaft end is not correctly oriented toward the corner 26, so the tip of the tip is attached to one of the flat plates 25 forming the corner. The rollers 18 come into contact first, and then the rotatable triangular base plate 17 receives a turning force, and one of the rear rollers 18 then comes into contact with it.
Therefore, the freely rotating detection object 14 is guided by the triangular substrate 17 sliding along the one flat plate 25 and approaches the corner 26 while turning, and finally the most advanced roller 18 moves toward the corner 26.
6, both touch switches 19 and 19 are activated and the extension is stopped.

In this state, the corner detector 14 is correctly oriented toward the corner 26, and the detection of the direction of the corner 26 is completed 34, but the detection axis 1
4 and the welding shaft 4, this deflection angle is detected as an electrical displacement by the potentiometer 21, and the displacement signal is used as a command to control R in the drive system.
A travel output is issued from the shaft control section to the motor 8 of the welding shaft 4, and the welding shaft 4 performs a travel operation 35, and the corner detector 14 and the joint shaft 3
At 6, the rough orientation of the welding shaft 4 is completed.

Following the completion of this direction determination, the operation is switched to copying mode 37, so that the Z-axis, Y-axis,
The R-axis and Z-axis control sections are activated.

As shown in FIG. 4, this copying mode 37 is
Among the various welding conditions given to the welding gun 6, the welding gun 6
Since the separation distance and approach angle with respect to the corner 26 of the flat plate 2 are specific control elements according to the present invention, these two control systems will be explained.
5.25, a command is issued to the Y-axis drive system 38 in the direction to extend the welding shaft 4, and the signal S1 from the length measuring device 7-1 and the signal S1 from the length measuring device 7-2 are sent to the Y-axis drive system 38. The signal is expanded until the sum of the signals matches the set value.

Concurrently with this, signals S1. with positive and negative polarities are sent from the length measuring devices 7-1 and 7-2. By comparing S2, a corrective action is given to the X-axis drive system 38, and the welding shaft 4 is moved in parallel until the ratio k of both signals matches the set value.

When the parallel movement of the welding shaft 4 is controlled in this way, the axes of the shaft 4 and the corner detection body 14 are no longer aligned, so the command signal S3 of the potentiometer 21 causes the R-axis drive system 40 to perform a corrective action. The welding shaft 4 is directed toward the corner 26 at a predetermined approach angle by the above-mentioned combined motion of parallel movement and travel, and positioning control is completed in which the welding gun 6 is faced to each other at a set separation distance. 41.

Thereafter, the corner detection body 14 is retreated by an appropriate length 42 and restored to its original position, completing the series of operating procedures 43.

In addition, the approach angle θ when the welding shaft 4 is directed toward the corner 26
An appropriate value for 2 is determined based on the welding work conditions based on the intersection angle θ1 of the corner 26, but as shown in Figure 2, the included angle between the axes of both length measuring instruments 7-1 and 7-2 is A relationship of α+θ1=180° is established between α and the crossing angle θ1, and one length measuring device 7-2 is set at an approach angle of θ2 and β+(θ1-02)−90° with respect to the welding axis 4. A setting signal 8 roughly proportional to the setting length of the length measuring device 7-1. It goes without saying that by making a selection in advance such that It is also formed into an isosceles triangle whose apex angle approximately approximates the intersecting angle θ1.

As is clear from the above description, for example, when the intersection angle θ1 of the corner 26 is 90', the approach angle θ2 is 45° along the equal dividing line.
When α-90°, β
-45°, k=1, that is, 51=82, and when θ1=90°θ2-30°, α-90'
, when β-30° is −to, when θ1=90° and θ2-60°, α-90°,
It is sufficient to set β=6o′ and /”N, respectively.

In this way, the approach angle θ2 of the welding shaft 4 can be determined.Next, in order to determine the separation distance from the tip corner 26 of the welding shaft 4, length measuring instruments 7-1, 7- 2 can be installed by selecting an appropriate value for the sum of the length measuring devices 7-1 and 7-2 in relation to the length l from the base point O to the tip of the welding gun 6.
S 1+ 7S 2-(D+7)CO3(α-
β) + (D+A)cosβ, that is, S□+S2−(D
+1)(CO3(-)+CO8β) If the setting values are determined so that the general constant value relationship holds, it is possible to perform directional control such that the approach angle is 02 and the separation distance is D.

After accurate pointing to the corner 26 is completed in this way, all that is left is to move to the base axis 3.
By raising or lowering the drive source 22,
The welding gun 6 attached to the tip of the welding shaft 4 that moves along the ridgeline 21 of the corner 26 can reliably weld the corner 26.

The present invention has the configuration and operation as described above, and includes a corner detector 14 that detects the corner 26, and a corner detector 14 that detects the corner 26.
Since the detection shaft 14 is formed as a separate mechanism from the actuator 4 that performs the work, the detection shaft 14 has a lightweight structure and can be operated easily and lightly, allowing the target corner 26 to be detected quickly and accurately. It has the feature that the actuator 4 can be quickly directed to the corner 26 which is the object of direction control.

Moreover, the drive mechanism for aligning the axis of the actuator 4 with the corner detection body 14 only requires a traveling R motion, so the structure is simple and control is easy. Control for pointing can be done by making the actuator 4 perform expansion/contraction Y and parallel movement X using the length measuring devices 7-1 and 7-2 attached to the actuator 4 as detection ends, so it is easy to use the drive system of a conventional robot. It can be applied without any modification, and has a wide range of adaptability.

Furthermore, the approach angle θ2 and the approach distance of the actuator 4 can be controlled by simply changing the setting ratio and magnitude of the contact length measuring devices 7-1 and 7-2, so adjustment is easy and the drive system is simple. It is a good circuit and has a versatile effect.

Furthermore, since the present invention allows the actuator 4 to be directed close to the corner 26 from the most appropriate direction, it is possible to more reliably and easily position the robot that performs precision processing such as welding. This is an automatic corner pointing device using a directional actuator, which is of great importance in industrial processes by streamlining work and reducing manpower.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of one embodiment of the device of the present invention, and FIG.
3 is a plan view illustrating the operating mode of the main parts of the apparatus, FIG. 3 is a diagram illustrating the operating procedure, and FIG. 4 is a block circuit diagram of the copying mode portion in FIG. 3. 3... Base shaft, 4... Actuator, 7-1, 7-
2... Contact type length measuring device, 14... Corner detection object, 16.
...Sensor, 21...Declination signal generator, 25...Flat plate, 26...Corner, α...Included angle of length measuring devices 7-1 and 7-2, θ1...Flat plate 25.25 crossing angle, θ2...
Approach angle, D... Separation distance of actuator 4, k...
・Both signal ratio of length measuring devices 7-1 and 7-2, R... travel time, X
... Parallel movement of the actuator 4, Y... Extension and contraction of the actuator 4, Z... Extension and contraction of the base shaft 3.

Claims (1)

[Scope of Claims] 1. An actuator 4 which has workability in a fixed direction and is capable of two-dimensional movement of parallel movement (X1), extension/contraction (Y), and travel (R) with an axis extending in the direction is made into a base shaft 4 capable of extension/contraction/Z. On the other hand, it has a sensor 16 capable of detecting a corner 26 formed by intersecting two flat plates 25, 25 at an appropriate intersecting angle θ1, and a sensor 16 capable of detecting a corner 26 formed by intersecting the two flat plates 25, 25 at an appropriate intersection angle θ1. A rotatable corner detection body 14 is pivotally supported on the actuator 4 such that its center of travel lies on the axis of the actuator 4. The actuator 4 is equipped with a declination signal generator 21 that emits an analog signal corresponding to the angular deviation, and the actuator 4 is equipped with a pair of contact length measuring instruments that are oriented toward the tip of the actuator in the plane in which the two-dimensional movement is performed. 7-1.7-2 is provided so as to extend at a predetermined angle α between the actuator shafts, and further, the actuator 4 is caused to travel R using an analog signal from the declination signal generator 21 to engage the corner detection body 14. driving such that the actuator 4 is moved in parallel by comparing both signals having polarities from both the contact type length measuring devices 7-1 and 7-2, and the ratio thereof matches a predetermined value k. An automatic corner pointing device for a directional actuator, characterized in that the actuator 4 can be directed toward the corner 26 at a predetermined approach angle θ2 by providing a system. 2. In the device according to claim 1,
A control circuit is added to the drive system, which compares the sum of polarized signals from both the contact length measuring devices 7-1 and 7-2 with a set value, and causes the actuator 4 to extend or contract Y using a signal corresponding to the difference. An automatic corner pointing device for a directional actuator, characterized in that the actuator 4 is directed toward the corner 26 at a predetermined approach angle θ2 so that it can approach the corner 26 at a predetermined distance. 3. In the device according to claim 1,
The drive system is formed of a control circuit that moves the actuator 4 in parallel so that the signals from both contact type length measuring devices 7-1 and 7-2 are equipolar and have equal values. An automatic corner pointing device for a directional actuator, characterized in that it can be directed to the corner 26 from the direction of the equisector of the intersecting angle θ1. 4. In the device according to claim 3,
A control circuit is added to the drive system, which compares the sum of polarized signals from both the contact type length measuring devices 7-1 and 7-2 with a set value, and causes the actuator 4 to extend or contract Y using a signal corresponding to the difference. An automatic corner pointing device for a directional actuator, characterized in that the actuator 4 is directed toward the corner 26 from the direction of the equisector of the intersecting angle θ1 and can approach the corner 26 at a predetermined distance.