JPS599716A - Original point positioning control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable to, for example, a welding robot or a traveling trolley, which includes a rotating body that can make one or two rotations with respect to a main body, and detects the rotational position of the rotating body using an incremental encoder. The present invention relates to a control device for controlling the origin position of the rotating body in motions such as profile welding equipment.

BACKGROUND ART Conventionally, welding robots are well known in which a rotating body is pivotably supported on a main body so as to be rotatable within one rotation, and the rotating position of the rotating body is detected using an incremental encoder. In this case, in order to determine the origin of the rotating body with respect to the main body, if one origin position detector is provided between the main body and the rotating body, the rotating body can be rotated from one end to the other. Even if the sensor is moved, the detector outputs an output only once, so the origin position can be easily determined based on the output signal. However, when the rotating body rotates one or two times with respect to the main body, the detector outputs twice while the rotating body rotates from one end to the other, and which output is The present invention was made in view of the above-mentioned circumstances, since it is not clear whether or not the origin position can be determined based on the signal. It is an object of the present invention to provide a control device that can reliably perform origin positioning with respect to the main body, with a simple and medium configuration, and examples thereof will be described in detail below.

In this embodiment, a rotating body is vertically supported on a main body having a steering mechanism, that is, a traveling truck, so as to be able to rotate once or twice, and a sensor and a welding torch are indirectly supported on the rotating body. Although the present invention will be described as a control device for determining the origin position (start position) of the rotating body relative to the main body in a traveling trolley type fillet profile welding device, the present invention is not limited to this embodiment.

w11w2 are workpieces, Wl is horizontal workpiece, W
2 is a vertical workpiece. And both works W1. W2 are positioned relative to each other as shown in FIG. 1, and temporary welding is performed in advance. WL is both work W1. This is a weld line formed by W2.

Reference numeral 1 denotes a main body of a traveling trolley (having a square planar shape in the embodiment), on which a total of four wheels 2 are mounted. All wheels 2 are operated by electric motor M1 attached to the bottom of truck 1.
They are configured to be driven in the same direction via a power transmission mechanism 3 consisting of a chain 3a, sprockets 3b and 3c, and bevel gears 3d and 3e. Although the details are not shown, E is an encoder for detecting the traveling distance connected to the wheel 2. Sl is a servo system including an electric motor M1 and an encoder E1.

4 is a steering mechanism, which includes an electric motor M attached to the bottom of the truck L.
2, the chain 4a and sprockets 4b, 4c
The structure is such that all wheels 2 can be simultaneously steered in the same direction and at the same angle. E2 is a steering angle detection encoder of the mechanism 4, although details are not shown. S2 is
This is a servo system including an electric motor M2 and an encoder E2.

5 is vertically supported by a shaft 5a at the upper center of the truck 1, and rotates a little less than 2 rotations (approximately 70
It is a rotating body that rotates (0 degrees). Although E3 is not shown in detail, it is an encoder for detecting the rotation angle of the rotating body 5.

S3 is a servo system including electric motor M3 and encoder E:3.

6 is a movable body supported by the rotating body 5 and movable in the horizontal direction by an electric motor M4 via a known ball screw set transmission mechanism 7; 3 and E4 are encoders for detecting the position of the movable body 6; . s4 is a servo system including electric motor M71 and encoder E4.

Reference numeral 8 denotes a tilting member which is connected to the movable body 6 by a horizontal shaft 8a in a direction perpendicular to the direction of movement of the movable body 6, and is movable up and down by an electric motor M5. E5 is an encoder for detecting the tilt angle of the member 8. S5 is electric motor M5 and encoder E
It is a servo system including 5.

Reference numeral 9 denotes a mechanism which is vertically supported by the lower part of the tilting member 8 and whose tip output member is horizontally rotated around an imaginary point, and in the embodiment, it is a parallel link mechanism consisting of two sets of parallelogram links. 3. The mechanism 9 has links 9a and 9b at the bottom of the member 8 with vertical shaft supports 9c and 9dL, and a bent link 9.
A link 9f with a lever 9f protruding from the tip is connected to the link 9e
Then, connect the tip of the bar 9f and the tip of the link 9b 9
A pair of parallelogram links gL and a lever protruding from the tip of the link 9a.A link 911 is attached to the tip of the link 9a, and a link 9j is attached between the image tips of the links 9f and 9h. 91 one set of 317
It consists of four openwork links and more. M6 is an electric motor that rotates the link 9a. Note that the tip output member of the mechanism 9, that is, the stock end link 9j is configured to serve as a holding part for the welding torch T. R6 is an encoder for detecting the angle of the torch T with respect to the welding line WL by the mechanism 9. R6 is a servo system including electric motor M6 and encoder E6.

SH is a profile sensor in the left-right direction, that is, the Y direction, supported at the tip of the holding member 9J, and in the embodiment, the holding member 9J
The vertical plane profiling rod 10 of the workpiece W2 is horizontally connected to the tip 10a and urged to protrude by a bullet (not shown), and the protrusion position detector (in the embodiment, a differential transformer) of the rod 10 is attached to the holding part 9J. )TR, and.

Note that at the protruding position of the rod IO at the preset reference output value of the transformer TR+, the shaft 9c.

The distance between the shafts 9e and 9e is set to be equal to the distance between the shaft 9k and the tip of the rod 10, and the distance between the shafts 9e and 9 and the distance between the shaft 9C and the tip of the rod 10 are set to be equal.

SV is a vertical direction (Z direction) tracing sensor supported on the holding member 9j, and in the embodiment, the holding member 9 a ”F
The protruding position detector ( In the embodiment, it is composed of a working transformer (TR2).

Note that the tilting member 8 is set to be horizontal at the protruding position of the rod 11 at a preset reference output value of the transformer TR2.

The attachment position of the torch T to the holding member 9j is the protruding position of the rod 10 at the reference output value of the transformer TR+ and the protruding position of the rod 11 at the reference output value of the transformer TR2, and the welding point of the torch T. The position P is set below the tip of the rod 1O and coincides with a horizontal plane passing through the tip of the rod 11.

Therefore, the position P of the welding point of the torch T is configured so as not to be displaced regardless of the rocking motion of the mechanism 9.

The SSs are Mitsutwitches, two of which are protruded from each side wall of the cart 1, or a total of eight switches, and can detect a collision of the cart 1 with the workpiece W2.

L'R is a first detection device that detects in which rotation range of the full scale the rotating body 5 is located with respect to a preset intermediate rotation position. This embodiment device L R is one rotating body 5
The protrusion 12 provided on the vertical shaft 5a of the
3a, and its tip is formed as a securing point with the protrusion 12 (in the example, two places of the loaf 14. an actuating body 13 whose rotation angle is limited by stoppers 17 and 18, and a detector S'W+ (a normally open limit switch in the embodiment) that detects the rotational position of the actuating body 13 due to the snap action biasing. It is made up of. Note that the switch SW1 is connected to the end 13b of the effecting body 13 on the opposite side from the roller 14.15.
This allows switching between ON and OFF.

HP is a second detection device that detects the origin position of the rotating body 5 with respect to the cart 1. This embodiment device, HP, has a protrusion 19 provided on the vertical shaft 5a, and the protrusion 19 allows the ON
, and a detector 5W2 (in the embodiment, a normally open limit switch) that is switched OFF.

C is the central processing unit CPU and memo! This is a control unit mainly based on a computer including JMEM. This control section C includes each servo system 81 to S6, a welding power source, and a control section C.
(a) a first means A1 for rotating the rotary body 5 in a direction in which the output signal thereof can change in accordance with the output signal from the switch SW1; , a second means A2 for rotating the rotating body 5 in either the positive or negative direction (in the embodiment, in the negative direction) when the output signal from the switch SW1 changes;
(c) Due to the rotation in this means A2, the output signal from the switch SW2 changes (in the embodiment, it changes from OFF, that is, the signal "O-1" to ON, that is, the signal "11")
When this occurs, the third means A3 is configured to rotate the rotating body 5 in either the positive or negative direction (positive direction in the embodiment). The output signal from or changes to the original output signal (
A fourth means A4 for stopping the moving body 5 once when the signal changes from 11 to 0 is included.

Furthermore, the operation of this embodiment will be explained based on the Flor chart of FIG. 7 and with reference to the signal diagram of FIG. 6.

First, the power to the profile welding device is turned on, and an origin positioning switch (not shown) is turned on. Then, all the components are at the preset origin position, that is, the steering angle of the wheels 2 is at a position where all wheels 2 are in the front-rear direction (X direction), and the rotating body 5 is set at a position where the moving direction of the moving body 6 is in the left-right direction (X direction). Furthermore, the movable body 6 is placed at a position where the reference output value of the transformer TRI is obtained, and furthermore, the moving body 6 is placed at a position where the reference output value of the transformer TRI is obtained.
Furthermore, −t/
The six j mechanisms 9 are placed at the positions shown in FIG. 3, respectively.

The origin positioning of the rotating body 5 will be described in detail below.

At the switching knob ST1, a determination is made as to whether it is the first origin positioning after the power is turned on.

As a result, if it is not the first time, as in step sT2, the rotating body 5 is moved at high speed (approximately 13 degrees/second in the embodiment) until the value of the counter by the encoder E3 returns to 1-o.
Moreover, when the value is around "0", a command is output to the electric motor M3 to rotate at a low speed (approximately 1 degree/second in the embodiment).

Further, if the determination result of step STI is the first time, the output signal of switch sw1 is ON as in step ST3.
That is, it is determined whether it is "l" or OFF, that is, "o-1".

As a result, the protrusion 12.19 now appears as the solid line 12.19 in FIG.
19 position, and the operating body 13 is at the rotating position indicated by the solid line in FIG.
8, the switch SW
The + output signal is "0", which means that the rotating position of the rotating body 5 with respect to the cart 1 is in the negative direction rotating region. Therefore, as in step S T4, the electric motor M
A command is output to step ST3, and as in step ST5,
The rotating body 5 is rotated until the output signal of the switch SW1 changes to "1".

If, on the other hand, the operating body 13 is in the rotating position shown by the two-dot chain line in FIG. The signal is l-11, which means that the rotating position of the rotating body 5 with respect to the trolley 1 is in the forward rotating region. Therefore, as in step ST6, a command is output to the electric motor M3 to rotate the rotating body 5 in the negative direction at the high speed, and as in step ST7, the output signal of the switch SW+ changes to "o-1". The rotating body 5 is rotated until this point is reached.

Note that the above-mentioned step ST3. S T4 and S T (
i constitutes the first means A1.

Then, in step ST5 or ST7, if the output signal of switch SW+ changes, step ST
As at Ts, a finger is output to the electric motor M3 to rotate the rotating body 5 in the negative direction at a medium speed (approximately 6 degrees/second in the embodiment), and as in step sT9, the output of the switch SW2 is output. The rotating body 5 is rotated until the signal changes to "l".

Note that the above-mentioned step ST5. sT7 and ST8 constitute a second means A2.

Then, in step S T9, if the output signal of the switch sw2 changes to 11'', that is, if the protrusion 19 turns on the switch sW2, step S
Like Too, a command is output to the electric motor M to rotate the rotating body 5 in the positive direction at a low speed (approximately 1 degree/second),
Then, as in step ST+, the rotating body 5 is rotated until the output signal of the switch SW2 also changes to [o1.

Note that the aforementioned steps STg and STIO constitute a fourth means A43.

Then, in step S Tl, if the output signal of switch sw2 changes to i 0 i, step 5T
12, an electric motor M for stopping the rotating body 5
A command is output at 3. At this time, each protrusion 12.19 is
The two-dot chain lines 12'+ and 19' in FIG.

It is.

Note that the aforementioned steps S Tl and 5T12 constitute a fourth means A4.

Then, as in step ST, 3, the encoder E.3
A command is output to set the value of the counter to "o".

In this way, the origin positioning of the rotating body 5 with respect to the cart 1 is performed, and the rotating body 5 is positioned at a position where the moving direction of the moving body 6 is in the Y direction.

When the origin positioning is completed, move the trolley L to the workpiece W]
1, so that the moving direction of the movable body 6 is approximately perpendicular to the welding line WL, and furthermore, the welding point RP of the torch T coincides with the welding line WL. to cent.

Then, when a start switch (not shown) is turned on, the power source Ws is turned on, and the cart I moves forward (in the X direction and toward the upper left in FIG. 1) at a preset speed.

At this time, the output value from the transformer TRI of the sensor SH is compared with a constant value, and the position of the moving body 6 is controlled so that the difference becomes zero, and the output value from the transformer TR2 of the sensor sv is also compared with a constant value. , the position of the tilting member 8 is controlled so that the difference therebetween is zero, and the position P of the welding point of the torch T is always aligned with the welding line WL. Although not described in detail, the direction of the welding line WL is always calculated based on the positional information of the welding point at regular intervals even if the welding line WL has a curve in the middle, and the direction of the welding line WL is always calculated from the position information of the welding point at regular intervals, The steering angle of the wheels 2 is controlled so that the attitude with respect to the line WL is always constant φ, and the moving position of the moving body 6 is almost constant, that is, the distance between the truck 1 and the welding line WL is almost constant. Further, the rotational speed of the wheel 2 is also controlled so that the welding speed is constant.

If welding workpieces W+ and W2 in which the welding line WL bends 90 degrees midway, the cart I will eventually collide with the workpiece W2, as shown by the solid line in Figure 8 (a).
At this time, two switches SS protruding from the front side of the bogie 1 output signals, and from then on, based on a sequential program set in advance, the rotation direction of the wheel 2, the steering angle of the wheel 2, and the rotating body are changed. The rotation angle of 5 is controlled, and the bent portions are welded as shown below.

First, the rotating body 5 is rotated to the right by a certain angle until the torch T reaches the position T shown in two-dot chain line T in FIG. 8(A), and the welding line WL is welded. Next, welding is stopped and the torch T is retracted to the position shown by the solid line in FIG. 8 (b). This retracted position is the same as the origin position of the moving body 6 described above. Next, after the trolley L is retreated to the 1 position indicated by the two-dot chain line in Figure 8 (B), the torch T is moved back to the position shown in Figure 8 (B).
The rotating body 5 is rotated to the right until it reaches the position indicated by the two-dot chain line T. Next, the trolley l is moved to the solid line position shown in Fig. 8 (c), that is, the sensor S.
After moving forward to the position where the tip of H contacts the workpiece W2, the wheel 2 is steered 90 degrees to the left, and the two-dot chain line 1 in FIG.
'The position where the trolley 1, which serves to place the can, collides with the workpiece W2 (the collision position is detected by the switch SS) is moved to the left by the switch. Next, the rotating body 5 is rotated to the left by a certain angle until the torch T reaches the solid line position (see FIG. 8). And the rotating body 5 is a torch T
Welding is performed while being rotated to the right by a certain angle until it reaches the position 1' shown in two-dot chain line in FIG.

In this way, the welding line WL near the bent point is welded, and further welding of the welding line WL to the right from the position of the two-point recess line T' (see FIG. 8) is performed in accordance with the above-mentioned pattern.

Note that even if the wheels 2 are steered at the bending point of the weld line WL, the attitude of the truck 1 does not change because all the wheels 2 are steered in the same direction and at the same angle.

Therefore, each time the rotating body 5 passes the bending point, it rotates 90 degrees to the right with respect to the cart IK.

Therefore, there are a large number of bent welding lines as described above, and when welding them one after another, each time welding for one bent welding line is completed, because the rotation angle of the rotating body 5 is limited. It is necessary to always perform origin positioning and return each component of this welding device to its starting position. However, if this is not the first home positioning after the power is turned on,
Since the contents of step ST2 are executed, the time required for positioning the origin is the same as that of steps ST3 to ST+ for the first time.
: Compared to the case of +, it can be much shorter.

The foregoing description is an embodiment in which, for example, instead of the protrusions 12.19, e.g. light emitting diodes or permanent magnets are used, while the limit switches SW1. A phototransistor or a reed switch may be used instead of SW2. -Also protrusion 12.
19 may be provided on the trolley 1 side, and the other components of the detection devices LR and HP may be provided on the rotating body 5 side. Further, the third means A3 may be configured to rotate the rotating body 5 in the negative direction when the output signal of the switch SW2 changes. Furthermore, if the "1" portion of the signal in FIG. 6(c) is, for example, entirely biased towards the 0 degree side and the origin position HPo is in the positive rotation area excluding the negative rotation area, , second means A2
The rotating body 5 may be rotated in the positive direction when the output signal of the switch SW+ changes.

Other sensors SH and SV may be non-contact types such as optical or electromagnetic types, or so-called alk sensors.In step ST2, as the value of encoder E:3 approaches 101, , high to medium speed,
It goes without saying that the technical scope of the present invention also includes the replacement of each structure with equivalents, such as the possibility of sequentially rotating the moving body 5 at a low speed and three speed changes.

As described above, this invention includes a device HP for detecting the origin position HP of the rotating body 5 with respect to the main body 1;
A device LR is provided to detect whether the rotating body 5 is in a positive or negative rotation region with respect to a preset intermediate rotation position, and the rotation direction of the rotating body 5 is controlled according to the output signal of the detector SW1. , detector SW1. Since the rotating direction of the rotating body 5 is controlled according to the change in the output signal of SW2, even when the rotating body 5 rotates 1 to 2 times with respect to the main body l, that is, the rotating body 5 rotates from one end to the other end. Even if the detection device HP outputs a signal twice while the rotating body 5 rotates up to 1, the origin position of the rotating body 5 relative to the main body 1 can be accurately and reliably determined.

[Brief explanation of drawings]

Each of the figures shows an embodiment of the present invention, in which Fig. 1 is an overall perspective view of a traveling truck type fillet profile welding device, FIG. 2 is a bottom view of the main body, that is, the traveling truck, and FIG. 3 is a view of the vicinity of the torch holding member. FIG. 4 is a plan view of the first and second detection devices, FIG. 5 is a block diagram of the control section, FIG. 6 is an output signal diagram of the first and second arrow detection devices, and FIG. 7 is a plan view of the first and second detection devices. is a flowchart, and FIG. 8 is an explanatory diagram of the operation. In the figure, 1 main body (traveling trolley), 5... rotating body,
5a...axis, C...control unit, LR/first detection device, S
W+・First detector, HP...Second detection device, HP (
+...Origin position, S W2...Second detector, A1 First means, A2...Second means, A3...Third means, A
4 Fourth means, 12...Protrusion, 13. Effecting body, 13a
・Shaft, 14.15...Engagement point, 16...Spring, 17
．． 18・Stotsuno<, 19 protrusion, -ch6o
Applicant: ShinMaywa Industries Co., Ltd. Agent Tadashi Bengami (and 1 other person) No. (z) M

Claims (3)

[Claims] (1) A main body, which is pivotally supported by the main body, and rotates more than 1 rotation.
a first detection device for detecting whether the rotating body is in a positive or negative rotation range with respect to a preset intermediate rotation position; a second detection device that detects the origin position with respect to the main body; and a control section that inputs output signals from the first and second detection devices; a first means for rotating the rotating body in a direction in which the output signal thereof can change based on; and the rotation in the first means changes the output signal from the first detection device. Sometimes, a second means for rotating the rotating body in either a positive or negative direction;
When the output signal from the second detection device changes due to the rotation in the means, the rotation body is moved to the correct position. f,
a third means for rotating the rotating body in either direction, and when the output signal from the second detection device changes to the original output signal due to the rotation in the third means, the rotating body and fourth means for stopping the origin positioning control device. (2) The first detection device is pivotally supported by a protrusion provided on one of the main body or the rotating body and the other rotating body or the main body, and the first detection device has its tip as a mating point with the protrusion. A patent comprising: an effecting body having a shape and a snap action applied by a spring, the rotation angle of which is limited by a stopper, and a detector for detecting a rotational position of the effecting body due to the snap action. An origin positioning control device according to claim 1. (3) The first means sets the rotating speed of the rotating body to a high speed, the second means sets the rotating speed of the rotating body to a medium speed, and the third means sets the rotating speed of the rotating body to a high speed. The origin positioning control device according to claim 1, wherein the speed is low.