JPH04336989A - Industrial robot - Google Patents

Abstract

PURPOSE:To carry out a work detecting and a work lifting operation safely as to an industrial robot. CONSTITUTION:In a robot 5 for opening and closing, a hand 7 is installed to a wrist 13 at the tip of an arm, and the hand 7 furnishes a work detecting mechanism 16 and a work opening/closing detecting mechanism 17. When the bonnet 3 of a car body as a work presses a work detecting rod 23, the first switch outputs a detecting signal. Then by driving the second cylinder 38, the fourth switch 40 confirms that a work holder 29 is inserted to the lower side of the bonnet 3, and the hand 7 is raised to open the bonnet 3. The fourth switch 50 confirms that the bonnet 3 is abutted to the work holder 29 and lifted.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to industrial robots.
In particular, the present invention relates to an industrial robot configured to detect workpieces and safely lift the workpieces.

0002

2. Description of the Related Art For example, in a painting line that paints the bodies of automobiles that are transported as workpieces, a painting robot or the like that operates in accordance with the transport speed of the vehicle bodies is employed to streamline the painting process. However, when painting the body of a car, not only the exterior of the car body but also the underside of the hood and the engine compartment are painted.

Therefore, in the above painting line, before painting the back side of the bonnet and the engine compartment, the worker opens the bonnet and inserts a support rod between the back side of the bonnet and the car body to support the bonnet in the open position. It was installed on. Thereafter, when the painting process for the back side of the hood and the engine compartment was completed, another worker removed the support rod and closed the bonnet to prevent damage to the vehicle body and bonnet.

0004

[Problem to be Solved by the Invention] Conventionally, however, in the painting line, a worker is required to open the bonnet and install the support rod, and another worker to remove the support rod and close the bonnet after painting the back side of the bonnet and the engine compartment. Met.

[0005] Therefore, it has been considered to use a robot to automatically open and close the bonnet.

For example, it is conceivable to install a suction cup at the tip of the robot's arm and use a vacuum device to suction the bonnet to prevent damage to the bonnet, but as the bonnet rotates in the opening direction, the angle of inclination of the bonnet increases. There is a risk that the bonnet may come off the suction cup because the

Moreover, when such a robot is used, the arrival of the workpiece at the work position is detected by an electrostatic dielectric proximity switch. Unable to detect
There is a risk that the robot hand will collide with the workpiece. Also, with this type of robot hand, it was not possible to confirm that the bonnet had been lifted and opened, so if the bonnet failed to open, the workpiece would be transported without the worker realizing that the bonnet had failed at all. Challenges arise.

[0008] Accordingly, an object of the present invention is to provide an industrial robot that solves the above problems.

[0009]

[Means for Solving the Problems] The present invention provides a displacement member that abuts against and displaces a workpiece, a first detection switch that detects the workpiece by displacement of the displacement member, and a detection switch of the first detection switch. a drive means driven by the operation; a work support member that moves below the workpiece by the drive means and faces the lower surface of the workpiece; and the workpiece support member contacts the lower surface of the workpiece and is displaced under the load of the workpiece. and a second detection switch for detecting the occurrence of the change.

0010

[Operation] When the displacement member contacts and displaces the workpiece, the first detection switch detects the workpiece, so the workpiece can be detected reliably without detection errors, and the workpiece support member moves below the workpiece. The second detection switch detects displacement due to the load of the workpiece, confirms that the workpiece has been lifted, and checks for operational errors.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 show a robot system to which an embodiment of an industrial robot according to the present invention is applied.

In both figures, a robot system is installed on a painting line 1 for painting car bodies (workpieces) 2 of automobiles. In this painting line 1, after painting the outer surface of the vehicle body 2, the back surface of the bonnet 3 and the engine room (not shown) provided below the bonnet 3 are painted.

The vehicle body 2 is transported by a transport device 4 in the X1 direction at a constant speed. An opening/closing robot 5 for opening and closing the bonnet 3 is provided on one side of the transport device 4.
A painting robot 6 for painting the back side of the bonnet 3 and the engine room is provided on the reflective side of the transport device 4.

The opening/closing robot 5 is an articulated robot having a base 5a, a rotating base 5b, a column 5c, and an arm 5d, and a workpiece at the tip of the arm 5d that holds the bonnet 3 when opening and closing it. A holding hand (hereinafter referred to as hand) 7 is attached.

Therefore, the hand 7 pivots in the horizontal direction by rotating the pivot base 5b, moves forward and backward by rotating the support column 5c, and moves up and down by rotating the arm 5d.

The painting robot 6 is the opening/closing robot 5 described above.
It is a multi-jointed robot similar to , and has a base 6a, a rotating base 6b, a support 6c, and an arm 6d, and a spray gun 8 for spraying paint is attached to the tip of the arm 6d.

The spray gun 8 sprays paint onto the back surface of the bonnet 3, etc., as will be described later, by the movement of each movable part of the painting robot 6.

The opening/closing robot 5 is provided on a first traveling device 9 extending parallel to the conveying device 4. This traveling device 9 has a base 9 fixed approximately to a floor surface 11.
a, and a traveling cart 9b to which the base 5a of the opening/closing robot 5 is fixed.

The traveling carriage 9b has a drive section (not shown), and moves on the base 9a in the workpiece conveyance direction while supporting the opening/closing robot 5. As will be described later, the opening/closing robot 5 moves in the X direction within a range from point A, where the bonnet 3 of the vehicle body 2 is opened, to point B, where the bonnet 3 is closed.

The painting robot 6 is connected to the first traveling device 9
In contrast, it is provided on a second traveling device 10 provided on the opposite side of the conveying device 4. The traveling device 10 has a base 10a fixed to a floor surface 11 so as to extend parallel to the conveying device 4.
and a traveling carriage 10b to which a base 6a of the painting robot 6 is fixed. Therefore, the opening/closing robot 5 and the painting robot 6 are provided to face each other on both sides of the conveying device 4. The traveling cart 10b moves on the base 10a while supporting the painting robot 6. The traveling range of this traveling carriage 10b is shorter than the traveling range of the traveling carriage 9b of the opening/closing robot 5, and is the range from point C to point D in FIG.

That is, the base 9a of the first traveling device 9
Comparing with the base 10a of the second traveling device 10,
The base 9a has a longer overall length than the base 10a, and the upstream end and downstream end of the base 9a are the same as the base 10a.
It protrudes above and downstream from both ends, respectively. Therefore, point A is located upstream of point C, and point B is located downstream of point D.

Before the vehicle body 2 is transported to the painting booth, both robots 5 and 6 are waiting at points A and C, respectively. Then, the vehicle body 2 is transported in the X1 direction by the transport device 4 with the bonnet 3 side at the beginning. When the hand 7 detects that the vehicle body 2 has arrived at point A, as will be described later, the traveling bogie 9b begins to move, and after a slight delay, the traveling bogie 1
0b starts moving in the X1 direction.

Therefore, the opening/closing robot 5 and the painting robot 6 move in the X1 direction together with the traveling carts 9b and 10b at the same speed as the vehicle body 2 while performing predetermined tasks taught in advance. That is, the painting robot 6 paints the back side of the hood 3 and the inside of the engine room.

Note that the opening/closing robot 5 is a painting robot 6.
is provided on the opposite side of the bonnet 3 from the lateral direction of the vehicle body 2.
will open. On the other hand, the painting robot 6 moves to a position downstream from the opening/closing robot 5,
The spray gun 8 is held from the front of the vehicle body 2. Therefore, both robots 5 and 6 do not interfere with each other and can efficiently perform their respective tasks.

Furthermore, while moving from point C to point D, the painting robot 6 finishes painting the back side of the bonnet 3 and the inside of the engine room, as shown in FIG. The painting robot 6 retreats the spray gun 8 from the transport path of the vehicle body 2, and the traveling trolley 10b temporarily stops and returns to the origin position (point C).

On the other hand, the opening/closing robot 5 moves from point A to the vehicle body 2.
The painting robot 6 moves in accordance with the painting robot 6, holds the bonnet 3 open until the painting robot 6 completes the work, and operates to close the bonnet 3 after the work is completed.

The configuration of the hand 7 attached to the tip of the arm of the opening/closing robot 5 will now be described.

As shown in FIGS. 4 to 6, the hand 7 is supported by a wrist portion 13 provided at the end of the arm 5d of the opening/closing robot 5. As shown in FIGS.

Reference numeral 14 denotes a support plate, which includes a vertical portion 14a to which the wrist portion 13 is fixed, and a horizontal portion 14b that rotatably supports a shaft 15a standing up from the base 15. base 15
is formed in a rectangular shape extending in the horizontal direction, and has a work detection mechanism 16 on its upper and lower surfaces, a work opening/closing detection mechanism 17 that supports the bonnet 3 as a work and detects when the bonnet 3 is opened. is provided.

As shown in FIG. 5, the pair of brackets 18 and 19 that stand up on the base 15 are provided with pressing members 21 and 22 that press the protruding piece 20a that protrudes from the bearing portion 20 on which the shaft 15a is supported from both sides. It is slidably provided. Since the pressing members 21 and 22 press the protruding piece 20a of the bearing part 20 coupled to the support plate 14 from both directions with substantially the same force by the pressing force of the coil springs 21a and 22a, the base 15 always presses both sides. The position where the forces of are balanced,
That is, it is held so as to extend in the front direction with respect to the bracket 14.

Note that even if the hand 7 comes into contact with a peripheral device (not shown) or the like when the arm rotates, for example, the base 15
Since the hand 7 can be rotated around a, it has a safe structure that can prevent the hand 7 from being damaged or damaging the peripheral equipment it comes into contact with. Then, when the base 15 rotates about the shaft 15a, when the hand 7 separates from the peripheral device with which it came into contact, the hand 7 automatically returns to its original position due to the pressing force of the pressing members 21 and 22.

23 is a workpiece detection rod (displacement member);
It is supported slidably in the axial direction (X direction) by a bearing 24 on the base 15, and an elastic contact portion 23a made of rubber or the like is provided at the tip thereof. Further, the workpiece detection rod 23 is biased in the X2 direction by the spring force of the coil spring 24a, and is displaced in the X1 direction when the vehicle body 2 is transported and the end of the bonnet 3 abuts on the contact portion 23a.

A large diameter portion 23b having a tapered surface is provided in the middle of the workpiece detection rod 23. When the workpiece detection rod 23 comes into contact with the workpiece and is displaced in the X1 direction, this large diameter portion 23b comes into contact with the roller contact piece 25a of the first switch for workpiece detection (first detection switch) 25, and the second 1 switch 25 is turned on. Since the first switch 25 does not come into direct contact with the bonnet 3, it is configured to be difficult to be damaged by the detection operation.

Note that the first switch 25 is supported by a bracket 26 extending from the base 15. In this embodiment, the workpiece detection mechanism 16 is the workpiece detection rod 2
3 and a first switch 25.

Further, the workpiece detection rod 23 is connected to the connecting member 26.
It is connected to a rod 28a of a first air cylinder 28 provided on the base 15 via. Therefore, due to the workpiece detection operation as described above, the workpiece detection lot 23 is
At the same time, the rod 28a is displaced in the same direction.

Note that the air cylinder 28 is connected to the first switch 2.
5 outputs a detection signal, compressed air is supplied to move the rod 28a in the X2 direction, and the workpiece detection rod 2
3 is separated from the bonnet 3. Thereby, the workpiece detection rod 23 is retracted so as not to get in the way when the bonnet 3 is opened. Further, along with the above operation of the air cylinder 28, a rod 38a of a second air cylinder 38, which will be described later, is driven in the X2 direction. Next, the work opening/closing detection mechanism 1
Each member constituting 7 will be explained.

Reference numeral 29 denotes a work support portion, which is provided at the tip of a work support rod 30 extending in the X direction on the lower surface side of the base 15. The work support portion 29 enters below the tip of the bonnet 3 and lifts the bonnet 3 as will be described later, so it is formed of elastic rubber or the like so as not to damage the bonnet 3.

Reference numeral 31 denotes a connecting block, into which the work supporting rod 30 is slidably inserted into one end on the right side in FIG. Further, a pair of arms 32 that support the connecting block 31 are connected to the other end on the left side of the connecting block 31.

The arm 32 is slidably fitted into a bearing 33a of a support portion 33 extending upward, is supported in a horizontal state by the support portion 33, and is rotated by the pressing force of the coil spring 36 at X2.
The upper end of the support part 33 is biased in the direction of the base 1.
It is rotatably supported by a shaft 34 horizontally suspended between the brackets 18 and 19 of No. 5.

The connecting block 31 has a shaft 31a projecting laterally, and a lower end 35a of a rod 35 extending in the vertical direction is fitted into the shaft 31a so as to be able to swing freely. Furthermore, a bracket 37 provided at one end of the connecting block 31
includes a second air cylinder (driving means) 38, a second switch 39 for detecting workpiece dropout, and a workpiece support section 29.
The third
A switch 40 is provided.

Reference numeral 41 is a lever for detecting workpiece dropout, and the long side 4
1a and a short side 41b, and the tip of the long side 41a protrudes forward by the workpiece support 29, so that if the bonnet 3 should come off the workpiece support 29, the bonnet 3 will come into contact with the tip. . Also, lever 41
The corner where the long side 41a and the short side 41b intersect is rotatably supported by the shaft 42a of the connecting member 42 provided at the tip of the rod 38a of the air cylinder 38, and the short side 41b
The tip is rotatably supported by a shaft 39b provided at the tip of the sliding portion 39a of the second switch 39.

[0042] Before operation, the rod 3 of the air cylinder 38
8a is in the position moved in the X1 direction, and the switch 39
The sliding part 39a of is moved by the spring force of the coil spring 43
Since the lever 41 protrudes in the direction, the lever 41 is held so that the long side portion 41a extends in the horizontal direction as shown in FIG.

The connecting member 42 is also connected to the workpiece support rod 30 mentioned above. Therefore, the workpiece support rod 30 and the workpiece supporter 29 are driven integrally with the lever 41 driven by the air cylinder 38 in the X2 direction.

Further, the rod 35 extending upward from the connecting block 31 is supported by a bearing 44 fixed to the base 14 so as to be slidable in the vertical direction. Also, this rod 3
A first spring receiver 45 and a second spring receiver 46 provided outside the first spring receiver 45 are fixed to the upper end 35b of the spring receiver 5 . The first spring receiver 45 has a large-diameter flange 45a at its upper portion, and an inclined portion is provided at the lower corner of the flange 45a.

Reference numeral 47 designates a cylindrical cover that holds down the rod 35, with a lower end 47a fixed on the base 15 and an upper end 47a fixed on the base 15.
7b comes into contact with the flange 46a of the second spring receiver 46,
This prevents the second spring receiver 46 from popping out.

A first coil spring 48 having a small diameter is interposed between the first spring receiver 45 and the bearing 44, and a second coil spring 48 having a large diameter is interposed between the second spring receiver 46 and the base 15. A coil spring 49 is interposed. Therefore, the rod 35 is urged upward by the spring force of the coil springs 48 and 49.
At the same time, the work opening/closing detection mechanism 17 connected to the connecting block 31 is held at the pre-operation position shown in FIG.

Reference numeral 50 designates a fourth switch (second detection switch) for detecting suspension of the workpiece, and the base 15 is rotated so that the roller end piece 50a is located below the flange 45a of the spring receiver 45.
is placed above. Further, on the opposite side of this switch 50, a fifth switch 51 for detecting overload of the workpiece is provided. This fifth switch 51 is a roller contact piece 51
The base 1 is positioned so that a is located at a lower position than the roller contact piece 50a of the fourth switch 50 and below the flange 45a.
5. Note that the switches 50, 51, etc. provided on the base 15 are housed in a box-shaped case 52 fixed on the base 15, and are protected from collision with peripheral equipment (not shown) or adhesion of dust, etc. Prevented.

Next, the operation of the hand 7 having the above configuration will be explained.

As shown in FIG. 1, when the vehicle body 2 is transported in the X1 direction and the leading portion of the vehicle body 2 reaches point A where the opening/closing robot 5 is waiting, the vehicle body 2 is transported as shown by the broken line in FIG. The front end of the bonnet 3 contacts the contact portion 23a of the workpiece detection rod 23.

The workpiece detection rod 23 is pressed by the bonnet 3 and displaced in the X1 direction (transfer direction), and the large diameter portion 23
b is the roller contact piece 2 of the first switch 25 for detecting the workpiece
5a. The switch 25 closes when the roller contact piece 25a is pressed and outputs a workpiece detection signal. At the same time, an air cylinder 28 connected to the workpiece detection rod 23
The rods 28a of are slidably displaced in the same direction. in this way,
The work detection rod 23 directly contacts the bonnet 3,
Since the workpiece is detected, there is no workpiece detection error as in the conventional case, and accidents such as the hand 7 colliding with the bonnet 3 and causing damage or damage to the bonnet 3 can be prevented.

As described above, when the workpiece detection signal is output, the traveling carriage 9b of the traveling device 9 moves at the same speed as the vehicle body 2.
Start moving in one direction. Further, when the work is detected by the switch 25, the first and second air cylinders 28
, 38 are supplied with compressed air as a driving source, and the rod 2
8a is driven in the X1 direction, and the rod 38a is driven in the X2 direction.

As shown in FIG. 1, the workpiece support portion 29 and lever 41 are inserted below the bonnet 3 by driving the rod 38a. Therefore, the work support member 29 is prevented from colliding with the bonnet 3, and the bonnet 3 can be opened safely.

Further, by driving the rod 38a in the X2 direction, the entire work opening/closing detection mechanism 17 rotates slightly clockwise about the shaft 34 as a fulcrum, as shown in FIG. 8, and the work supporting portion 29 and lever 41 are lowered. As a result, the protrusion 32a provided on the rod 32 is connected to the roller contact piece 40 of the switch 40.
a. Therefore, the switch 40 outputs a detection signal, and the opening/closing robot 5 moves the workpiece support part 49 and the lever 41 to the bonnet 3 in response to the detection signal from the switch 40.
After confirming that the bonnet 3 is inserted under the bonnet 3, open the bonnet 3.

The opening/closing robot 5 has a column 5c and an arm 5d.
, lifts the hand 7 upward by the action of the wrist part 13,
As shown in FIG. 9, open the bonnet 3 by rotating it in the G direction. Since the tip of the bonnet 3 of the hand 7 moves in an arc to open it, the arm 5ad turns and moves in the X2 direction while moving upward along the arc-shaped locus of movement.

Then, the hand 7 moves in an arc from point E to point F, and stops at point F, where the bonnet 3 is open, and holds the bonnet 3 in an open state.

As described above, when the hand 7 begins to rise, the workpiece support portion 29 first comes into contact with the lower surface of the tip of the bonnet 3. Furthermore, as hand 7 rises,
The load of the bonnet 3 acts on the workpiece support portion 29 . Therefore, the workpiece support portion 29 moves further downward, and the rod 35 extending upward from the connection block 31 also descends while compressing the first coil spring 48.

As a result, the flange 45a provided on the upper end 35b of the rod 35 comes into contact with the roller contact piece 50a of the fourth switch 50 for detecting suspension of the workpiece. In this way, when the detection signal is output from the switch 50, the opening/closing robot 5 confirms that the bonnet 3 is suspended by the hand 7, and performs the opening operation of the bonnet 3.

However, when the load on the bonnet 3 exceeds the specified load, the workpiece support portion 29 is further pushed down, and the second coil spring 49 is also compressed due to the lowering of the rod 35. Then, the flange portion 45a at the upper end of the rod 35 comes into contact with the roller contact piece 51a of the work load over-detection switch 51.

In this manner, when the switch 51 outputs a detection signal indicating that the work load is over, the opening/closing robot 4 determines whether any object is placed on the bonnet 3 or not.
Alternatively, it is determined that the bonnet 3 cannot be rotated, and the opening operation of the bonnet 3 is stopped. At the same time, an alarm is issued to notify the operator of the abnormality.

Furthermore, during the opening operation of the bonnet 3, the tip of the bonnet 3 may come off the workpiece support section 29 and fall off. In that case, the bonnet 3 comes into contact with the lever 41 extending below the workpiece support section 29 .

[0061] The lever 41 is moved clockwise (
) in FIG. 7, and presses the sliding portion 39a in the X1 direction. As a result, when the sliding portion 39a slides in the X1 direction, the second switch 39 outputs a work dropout detection signal, and the opening/closing robot 5 stops. Then, the opening/closing robot 5 issues an alarm to inform the operator that the work has fallen off.

It should be noted that when the opening/closing robot 5 stops due to the occurrence of an abnormality as described above, the painting robot 6 also stops at the same time. Then, when the abnormality is resolved, the opening/closing robot 5 and the painting robot 6 execute their respective operations.

Further, when closing the bonnet 3, the opening/closing robot 5 and the hand 7 perform an operation opposite to the opening operation described above to close the bonnet 3.

In the above embodiment, the opening/closing robot 5 having the hand 7 for opening the bonnet 3 has been described as an example, but the invention is not limited to this and can be applied to robots configured to lift other workpieces. Of course you can.

It goes without saying that the present invention can also be applied to robots used in processes other than painting processes.

[0066]

As described above, in the industrial robot according to the present invention, the arrival of the workpiece can be directly detected by detecting the displacement of the displacement member in contact with the workpiece with the first detection switch. It is possible to prevent the robot from colliding with the robot or the workpiece, and it is possible to reliably prevent damage to the robot or workpiece. Further, since the work supporting member is driven below the work by the detection operation of the first detection switch, the work supporting member is prevented from colliding with the work, and the work can be lifted safely. Furthermore, since the second detection switch can detect that the workpiece has been lifted based on the displacement of the workpiece support member, it can be confirmed that the workpiece is being held even when the robot is operating, increasing the reliability of the robot's work operations. It has the advantage of being able to further improve the performance.

[Brief explanation of drawings]

FIG. 1 is a plan view of a robot system to which an embodiment of an industrial robot according to the present invention is applied.

FIG. 2 is a front view for explaining the operation of the opening/closing robot when opening the bonnet.

FIG. 3 is a front view for explaining the operations of an opening/closing robot and a painting robot.

FIG. 4 is an enlarged vertical cross-sectional view of the hand for explaining essential parts of the present invention.

FIG. 5 is a plan view of the hand.

FIG. 6 is a longitudinal sectional view of the hand seen from the front.

FIG. 7 is a longitudinal sectional view for explaining the operation of the hand.

FIG. 8 is a longitudinal cross-sectional view for explaining the operation when the hand lifts the hood.

FIG. 9 is a side view showing the operation when opening the hood.

[Explanation of symbols]

1 Painting line 2 Vehicle body 3 Bonnet 4 Conveyance device 5 Opening/closing robot 6 Painting robot 7 Hand 9,10 Traveling device 15 Base 16 Work detection mechanism 17 Work opening/closing detection mechanism 23 Work detection rod 25 First switch 28 First air cylinder 29 Work support part 31 Connecting block 38 Second air cylinder 39 Second switch 40 Third switch 41 Lever 50 Fourth switch 51 Fifth switch

Claims (1)

[Claims] 1. A displacement member that abuts on and displaces a workpiece, a first detection switch that detects the workpiece based on the displacement of the displacement member, and a driving means that is driven by the detection operation of the first detection switch. , a work supporting member that moves below the work by the driving means and faces the lower surface of the work; and a second member that detects that the work supporting member is in contact with the lower surface of the work and is displaced under the load of the work. An industrial robot characterized by having a detection switch.