JP3292948B2 - Industrial robot equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot that performs various types of processing on a workpiece in a factory,
In particular, the present invention relates to a technique for synchronizing a work conveyed by a hanger and a robot that processes the work.

[0002]

2. Description of the Related Art Conventionally, in a factory for processing the body of an automobile, as shown schematically in FIG.
1 is supported by a hanger 02, the hanger 02 is hung on a transport rail 03, and a driving claw 06 provided on a chain 05 driven by a motor 04 along the transport rail 03 is engaged with the hanger 02. The body 01 is configured to be conveyed by engaging the pawls 07 and transmitting the drive.
The work such as welding and nut tightening is performed while moving the work means 09 at the tip of the robot 08 along. In the drawing, reference numeral 010 denotes a control unit for controlling the driving of the robot 08. In such a configuration, the control unit 010 detects a moving speed (position) of the hanger 02 by receiving a signal from the pulse generator 011 that generates a pulse in accordance with the driving of the motor 04, and accordingly drives the robot 08. Is configured to be controlled. Further, as another industrial robot device, for example, one described in Japanese Patent Application Laid-Open No. 61-11893 is known. This conventional industrial robot apparatus is provided with a plurality of optical sensors for detecting the position of the work to be conveyed as described above, and detects the position of the work three-dimensionally based on signals from these sensors. The drive of the robot is controlled based on the detection position.

[0003]

However, in the former prior art, the speed of the body (work) 01 is detected by a signal from the pulse generator 01, and the movement of the body 01 and the robot 08 are detected based on the detected speed. Since the configuration is synchronized with the operation of (1), there is an advantage that the configuration is simple and inexpensive, but it has the following problems. That is, in the configuration in which the hanger 02 is engaged with the chain 05 to move the hanger 02 and the body 01, the friction between the transport rail 03 and the hanger 02 is not constant, or the transport rail 03 is inclined. Then, the driving claw 06 of the chain 05 and the engaging claw 07 of the hanger 02 are always engaged, and the hanger 02 is constantly
The hanger 02 is pushed by the chain 05 after the engagement of the claws 06 and 07
After advancing further (go), the go-stop may be repeated, such as stopping once (stop) and again starting to move with both claws 06 and 07 engaged (go). Therefore, although the movement of the chain 05 and the movement of the hanger 02 are not always synchronized, in the former technique, the signal of the pulse generator 011 synchronized with the motor 04 for driving the chain 05 is used to drive the robot 08. Are synchronized, the movement of the robot 08 and the movement of the body 01 may not be synchronized, and there is a possibility that a work defect may occur. On the other hand, in the latter conventional technology, the position of the work can be detected three-dimensionally and the drive of the robot can be completely synchronized with the movement of the work, but a plurality of optical sensors are required. And there was a problem that the cost was high. SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to improve the working accuracy of a robot by synchronizing the robot with the movement of a work using inexpensive means.

[0004]

In order to achieve the above-mentioned object, the invention according to claim 1 is a work means for performing a predetermined work such as welding or nut tightening on a work to be worked, A robot capable of performing the work while moving the work means in accordance with a predetermined program, comprising: a moving means for freely moving the work means; and a robot in which the robot is installed and capable of moving. A transfer rail routed above an operation range that is a range, a hanger movable along the transfer rail and formed to support the work;
A power chain that is driven endlessly along the transport rail by a driving force provided by a driving unit, and a driving claw provided on the power chain and formed to be able to engage with an engaging claw provided on the hanger. The drive claw is engaged with the engagement claw, a driving force is applied to the hanger from the power chain, and the work moves together with the hanger along the transport rail, and the robot performs a predetermined operation on the moving work. In an industrial robot apparatus configured to perform the operation, a hanger driving device configured to be able to move a support arm along the transfer rail is provided within a working range of the robot, and the support arm is provided with the hanger. It is possible to change between a state in which a predetermined portion is clamped and a state in which the support arm is not clamped, and in this state in which the support arm is not moved by the hanger driving device. Configured hanger clamp provided at so as not to interfere with the hanger and the workpiece,
A control unit for controlling the operation of the hanger clamp, the hanger drive device and the robot is provided. When the control unit detects that the hanger has been sent to the working range of the robot, the hanger clamps a predetermined portion of the hanger. After that, the hanger is moved to a position where the engagement claw of the hanger is disengaged from the drive claw of the power chain, and the hanger is moved by the hanger driving device while maintaining the disengaged state. It is characterized in that a predetermined operation is performed by a robot in synchronization with the operation of the hanger driving device. According to a second aspect of the present invention, in the industrial robot apparatus according to the first aspect, a pulse generator that outputs a signal indicating a driving state of the first driving unit is provided, and the control unit is configured to engage the two claws. When the hanger is moved by the hanger driving device while maintaining the unlocked state, the hanger is moved in synchronization with the output of the pulse generator. According to a third aspect of the present invention, in the industrial robot apparatus according to the first or second aspect, the hanger clamp is supported to be vertically movable with respect to the support arm, and the hanger clamp is moved up and down. Two driving means are provided,
At the upper end of the hanger, a plate is provided as a predetermined portion to be clamped by the hanger clamp, and the hanger clamp, when lowered with respect to a support arm, a main body facing the plate in the transport direction, A lock body rotatably supported by the main body at a position abutting or approaching the main body from a true side of the main body and at a position away from the main body,
The third driving means for the locking member is rotated, provided with, you characterized in that said locking member is rotated to a position to be close to or abut against the body is configured to sandwich the plate.

[0005]

The operation of the invention will be described. The work to be worked is suspended on a transport rail while being supported by a hanger. Then, the driving claw provided on the power chain moving along the transport rail engages with the engaging claw provided on the hanger, and the driving force of the power chain is transmitted to the hanger, and the work is transferred to the hanger. The supporting hanger moves along the transport rail. In this manner, when the hanger and the work are conveyed to the working range of the robot, the control unit detects the hanger and firstly clamps a predetermined portion of the hanger by the hanger clamp, and then, the control unit In order to move the hanger forward at a speed higher than the moving speed of the power chain so as to disengage the engagement with the engaging claw, the support arm provided with the clamp is moved by the hanger driving device, and furthermore, in this manner, The hanger driving device is operated to move the hanger while maintaining the state where the dovetail is disengaged, and the work is transported, and during this time, the robot performs a predetermined operation. Synchronize with the operation of the hanger drive. That is, since the hanger is held by the hanger clamp, the movement of the hanger and the work supported by the hanger are synchronized with the movement of the hanger clamp, and the movement of the hanger clamp is performed by the hanger driving device. Therefore, by synchronizing the robot with the operation of the hanger drive device, the robot works in synchronization with the actual movement of the work, and high machining accuracy can be obtained. According to the second aspect of the present invention, when the hanger is moved by the hanger driving device while maintaining the state in which the engagement claw and the driving claw are disengaged as described above, the first driving means that is driven by the power chain is used. The hanger driving device is operated in synchronization with the output of the pulse generator indicating the driving state. In this case, the movement of the driving pawl is detected with high accuracy, and the disengagement state of both pawls is reliably maintained. Is done. According to the third aspect of the present invention, when the plate provided on the upper end of the hanger is clamped by the hanger clamp, first, the second driving means causes the hanger clamp support arm to reach a height at which the body of the hanger clamp faces the plate. Then, when the plate comes into contact with or comes close to the main body, the third driving means is driven to rotate the lock body, and the plate is sandwiched between the main body and the lock body. After that, when the work is completed, the lock body is returned to the original position by the third driving means to release the holding state, and the hanger clamp is raised by the second driving means until the hanger clamp body and the hanger plate no longer face each other. Then, the hanger clamp and the support arm are returned to the original positions by the hanger driving device. In this case, since the main body and the plate do not face each other, the hanger clamp can be moved without collision between the main body and the plate.

[0006]

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In describing the embodiments, a description will be given of an example of an automobile production line. (First Embodiment) FIG. 1 is an overall view showing an industrial robot apparatus according to a first embodiment. In the figure, reference numeral 1 denotes a transport rail, which is routed along an upper part of a factory line. As shown in FIG. 2, the transport rail 1 has a U-shaped cross section opposed to a lower end of a support frame 2. It is provided and configured.
A hanger 3 is suspended from the transport rail 1. That is, the hanger 3 is provided with a roller 3b for rolling the transport rail 1 above the base 3a at the upper end, and a frame 3 for supporting the work 4 below the base 3a.
c is connected. At the upper center of the support frame 2, a power rail 5 is routed along the transport rail 1 at a position above the transport rail 1. On the power rail 5, a roller 6a connected to a power chain 6 is provided so as to roll. That is, as shown in FIG. 1, the power chain 6 is provided with the rollers 6a at predetermined intervals.
Are connected, and the driving force can be transmitted by a first motor 7 as a first driving means. When the first motor 7 is driven, the power chain 5
It is configured to move endlessly along. In the drawing, the left direction in the drawing is the traveling direction of the work.
In addition, as shown in FIG.
At the position where the roller 6a is provided and at other positions, a driving claw 6b is protruded downward. The drive claw 6b is configured to be able to engage in the transport direction with an engagement claw 3e protruding upward at a front end of an arm 3d extending back and forth from the hanger 3. That is, when the power chain 6 is moved by the driving force of the first motor 7, the driving claw 6b and the engaging claw 3e are engaged, and the hanger 3 moves at the same speed as the power chain 6 along the transport rail 1. Thus, the work 4 supported by the hanger 3 moves along the factory line.

Returning to FIG. 1, a robot 8 is provided on the factory floor below the transfer rail 1. The robot 8 is, for example, a working unit (working unit) that performs welding on the tip of the arm 8a or tightens a nut.
8b are provided. The robot 8 is fixed to the floor surface or can move on the floor surface. In any case, based on the control of the control unit 9, the working unit 8b moves the work 4 to be conveyed. It is configured to perform the work while moving with. The first motor 7 is provided with a pulse generator 10, and a signal synchronized with the driving of the first motor 7 is input to the control unit 9. The configuration described above is the same as in the related art.

The characteristic configuration of the present invention will be described below. A hanger drive device 11 is provided along both rails 1 and 5 in a work range in which the robot 8 works. This hanger driving device 11 uses the same device as that generally used for moving the robot 8 conventionally, and includes a second motor 12 as a driving source.
A traveling shaft (not shown) rotated by the second motor 12 and routed substantially parallel to the power rail 5 and the transport rail 1; and a rotation of the traveling shaft mounted on the outer periphery of the traveling shaft. And the support arm 13 that moves in the transport direction. Therefore, the second motor 1
2 drives the support arm 1 according to the rotation direction.
3 is configured to move along the traveling direction of the work, which is the horizontal direction in FIG. The support arm 13 includes
Plate 3f projecting upward from the upper end of the hanger 3
Is provided. That is, the hanger clamp 14 is, as shown in FIG.
It is vertically movably supported by the support arm 13, and is configured to be vertically movable by driving a motor or a cylinder (not shown) as a second driving means. The main body 14a is formed in a substantially rectangular shape by a plate-shaped material that is configured to be opposed in the transport direction and not to be opposed in the transport direction, and provided on the main body 14a as shown in FIG. And a lock body 14d driven by a cylinder 14c as a third drive means. Therefore,
When the cylinder 14c is extended, the plate 3f can be sandwiched between the main body 14a and the lock body 14d, as shown by a solid line in FIG.
When the length 4c is shortened, as shown by an imaginary line in the figure, the lock body 14d can be lifted to release the holding state. As shown in the figure, the main body 14a is provided with a photoelectric or contact type plate detection sensor 15 for detecting that the plate 3f has contacted or approached the main body 14a.
5 (in this embodiment, ON when plate 3f is detected)
And OFF otherwise) is input to the control unit 9.

Returning to FIG. 1, when the hanger 3 arrives at the work start position of the work range of the robot 8 on the transport rail 1, the front end of the hanger 3 collides with the transfer rail 1 to detect this. (In the embodiment, it is ON at the time of collision, and OFF at other times.) The hanger arrival sensor 16 and the front end of the hanger 3 collide when the hanger 3 exceeds the end position of the working range of the robot 8. An overrun detection sensor 17 (ON in the present embodiment and OFF in other cases) for detection is provided, and signals from both sensors 16 and 17 are also input to the control unit 9.

Next, the operation of the embodiment will be described with reference to the flowchart of FIG. 5 showing the control flow of the control unit. When the industrial robot device operates, the first motor 7
Is driven to move the power chain 6, and the hanger 3 engaged with the driving claw 6b of the power chain 6 by the engaging claw 3e is moved from right to left in FIG. When the front end of the hanger 3 collides with the hanger arrival sensor 16 due to this movement, the output of the hanger arrival sensor 16 changes from OFF to ON, and the process proceeds from step S1 to S2.
Is lowered. By the way, initially, the support arm 13 that supports the hanger clamp 14 is located at the origin position,
At this origin position, when the hanger 3 is at a position where it collides with the hanger arrival sensor 16, the hanger clamp 1 is lowered.
As shown in FIG. 1, the main body 14a of the hanger 4 and the play 3f of the hanger 3 are separated from each other in the hanger traveling direction. Therefore, in step S3, the plate detection sensor 15 is initially off, and step S3 is repeated. When the hanger 3 is moved and the plate 3f contacts or approaches the main body 14a of the hanger clamp 14 and the plate detection sensor 15 is turned on, the process proceeds from step S3 to S4, where the control unit 9 drives the cylinder 14c to drive the cylinder 14c. The plate 3f is sandwiched between the main body 14a and the lock body 14d by rotating the lock body 14d (FIG. 3).
reference). Here, the control unit 9 drives the second motor 12 at a higher speed than the first motor 7 and
Is advanced by about 50 mm, for example, as shown in FIG.
The engaging claw 3e is separated from the driving claw 6b (step S
5). Further, the control unit 9 is moved from this state.
Drives the second motor 12 of the hanger drive device 11 in synchronization with the output of the pulse generator 10 (step S
6). Therefore, the hanger 3 advances while the distance m between the engaging claw 3e and the driving claw 6b is kept constant. At this time, since the hanger 3 is firmly held by the hanger clamp 14, the position of the hanger 3 is completely synchronized with the driving state of the second motor 12, and the driving claw 6b of the power chain 6
As in the case of engaging with the robot, the go-stop is not repeated and the robot 8 is not synchronized. The control unit 9 performs a predetermined operation by the robot 8 in a state where the movement of the hanger 3 is completely synchronized with the driving state of the second motor 12 in this manner. In this case, since the position of the hanger 3 can be accurately known, the operation can be performed reliably. Thereafter, in step S7, it is determined whether the operation of the robot 8 has been completed,
If the operation is completed, the operation proceeds to step S8. If the operation is not completed, the operation proceeds to step S11 to determine whether the overrun detection sensor 17 is ON or OFF. Proceed to step S12. That is, if the operation of the robot 8 is completed successfully, the process proceeds to step S8. If the hanger 3 overruns beyond the work range of the robot 8 before the operation of the robot 8 is completed, the process proceeds to step S12.

When the robot 8 has successfully completed the operation and proceeds to step S8, the control unit 9 shortens the cylinder 14c to release the holding of the plate 3f by the hanger clamp 14, and then releases the hanger clamp 14. The support arm 13 and the hanger clamp 14 are returned to the home position by rotating the second motor 12 in the reverse direction (step S9).

On the other hand, if the hanger 3 overruns before the work of the robot 8 is completed, the control unit 9 outputs a signal for stopping the driving of the first motor 7 (step S12) to stop the power chain 6. (Step S13) In this state, the operation of the robot 8 is continued to end the operation of the robot (Step S14). Thereafter, the control unit 9 shortens the cylinder 14c to release the holding of the plate 3f by the hanger clamp 14. (Step S15) Then, a signal for restarting the driving of the first motor 7 is output (Step S17),
After activating the power chain 6 (step S18),
Proceeding to step S10, the support arm 13 and the hanger clamp 14 are returned to the home position.

As described above, in the first embodiment, in the working range of the robot 8, the hanger 3
Is moved completely synchronously with the second motor 12,
As in the related art, the operation of the robot 8 can be reliably performed without the go-stop being repeated and the synchronization is not lost, and a plurality of expensive optical sensors are provided to obtain such complete synchronization. Without using the existing hanger driving device 11 for moving the robot 8, the hanger driving device 1
Hanger clamp 1
4 can be achieved with a simple and inexpensive configuration. Further, in such a configuration, the existing line can be retrofitted as it is, and there is little change in the existing line. In this respect, too, there is an advantage that capital investment can be suppressed and it is economically advantageous. In addition, in the first embodiment, since the hanger 3 is completely disconnected from the power chain 6 while the robot 8 is working, vibration of the hanger 3 due to vibration of the power chain 6 can be eliminated, and work accuracy can be reduced. Is improved.

[0015]

[0016]

[0017]

[0018]

[0019]

As described above, in the industrial robot apparatus according to the first aspect, at the time of working of the robot, the hanger is separated from the drive transmission system by the power chain and the hanger is moved by the hanger drive device. In addition, since the operation of the robot is synchronized with the hanger driving device, the robot performs the operation in synchronization with the actual movement of the work, and has an effect that high machining accuracy can be obtained. According to the second aspect of the present invention, when the hanger is moved by the hanger driving device while maintaining the state in which the engagement claw and the driving claw are disengaged, the driving state of the first driving means driven by the power chain is shown. Since the hanger drive device is configured to operate in synchronization with the output of the pulse generator, it is possible to obtain the effect that the movement of the drive claw is detected with high accuracy and the disengagement state of both claws is reliably maintained. . In the invention described in claim 3, that-out <br/> in that a more complete structure of the configuration of the hanger clamp.

[Brief description of the drawings]

FIG. 1 is an overall view of an industrial robot apparatus according to a first embodiment of the present invention as viewed from a side.

FIG. 2 is a front view of a main part of the first embodiment.

FIG. 3 is an enlarged side view of a main part of the first embodiment.

FIG. 4 is an enlarged side view of a main part of the first embodiment.

FIG. 5 is a flowchart illustrating a control flow of the control unit according to the first embodiment.

FIG. 6 is an overall view showing a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conveyance rail 2 Support frame 3 Hanger 3a Base 3b Roller 3c Frame 3d Arm 3e Engagement claw 3f Plate 4 Work 5 Power rail 6 Power chain 6a Roller 6b Driving claw 7 First motor (first driving means) 8 Robot 8a Arm 8b Working part (working means part) 9 Control unit 10 Pulse generator 11 Hanger drive device 12 Second motor 13 Support arm 14 Hanger clamp 14a Main body 14b Bracket 14c Cylinder (third drive means) 14d Lock body 15 Plate detection sensor 16 Hanger arrival sensor 17 Overrun detection sensor

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-208525 (JP, A) JP-A-61-111893 (JP, A) JP-A-7-125828 (JP, A) 64386 (JP, U) Actually open 63-82691 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B25J 13/00 B65G 35/00

Claims (3)

(57) [Claims] 1. A work means for performing a predetermined work such as welding or nut tightening on a work to be worked, and a moving means for freely moving the work means, the work means being provided in accordance with a predetermined program. A robot capable of performing the work while moving the work means, a transfer rail routed over a work range in which the robot is installed and in which the robot can move, A hanger movable along a rail and capable of supporting the work; a power chain driven endlessly along the transport rail by a driving force provided by a first driving means; And a driving claw formed so as to be able to engage with an engagement claw provided on the hanger. A work force is applied from the work chain along with the hanger to move the work along the transfer rail, and the robot performs a predetermined work on the moving work. A hanger driving device configured to be able to move a support arm along the transfer rail is provided within the range, and the support arm can be changed between a state in which a predetermined portion of the hanger is held and a state in which the hanger is not held. In addition, a hanger clamp configured so as not to interfere with the hanger and the workpiece when the support arm is moved by the hanger driving device in the non-sandwiched state is provided, and a control unit for controlling the operation of the hanger clamp, the hanger driving device and the robot is provided. The control unit controls the working range of the robot. When it is detected that the hanger has been sent, a predetermined portion of the hanger is clamped by the hanger clamp, and then the hanger is moved to a position where the engagement claw of the hanger and the drive claw of the power chain are disengaged. The hanger is moved by the hanger driving device while maintaining the release state, and during this time,
An industrial robot apparatus configured to perform a predetermined operation by the robot in synchronization with an operation of a hanger driving device. 2. A pulse generator for outputting a signal indicating a driving state of the first driving means, wherein the control unit moves the hanger by a hanger driving device while maintaining the disengagement state of the claws. 2. The industrial robot apparatus according to claim 1, wherein the movement is performed in synchronization with the output of the pulse generator. 3. The hanger clamp is supported to be vertically movable with respect to the support arm.
A second driving unit for vertically moving the hanger clamp is provided, and a plate as a predetermined portion to be clamped by the hanger clamp is provided at an upper end of the hanger, and the hanger clamp is lowered with respect to a support arm. Sometimes, a main body facing the plate in the transport direction, a lock body rotatably supported by the main body at a position abutting or approaching the main body from the real side of the main body and at a position away from the main body, And a third drive means for rotating the lock body, wherein the lock body is rotated to a position where the lock body approaches or comes into contact with the main body to clamp the plate. 1 or 2 industrial robot equipment described.