JP5907411B2 - Work assembly device - Google Patents

Description

  The present invention relates to a work assembling apparatus for assembling a work on a work object.

  When assembling a work on a work object, especially in order to perform the work smoothly when assembling a work where the position of the work object to be assembled is indefinite and the assembly part cannot be seen Various means have been proposed (for example, Non-Patent Documents 1 to 3, Patent Documents 1 to 4).

  As a technique for automating the assembly, there is a method using a teaching playback type robot. In this case, the assembly is generally realized by using a passive mechanism (Non-Patent Document 1) on the robot hand. If there is a deviation between the workpiece and the work object, the passive mechanism absorbs the deviation and performs assembly. However, these are limited to a small amount of copying operation (about several mm) required for fitting, such as fitting of a pin and a shaft.

  As a technique for supporting manual assembly, there is a means using an assisting device (Non-Patent Document 2). While confirming the positional relationship between the workpiece and the work target with the eyes, the operator operates the assisting device to perform the assembly work.

  In addition to the assisting mechanism, there is a hand guide system (Non-Patent Document 3) in which an operator operates a robot to perform assembly as a technique for supporting manual assembly. The operator confirms the positional relationship between the workpiece and the work target with his / her eyes, and performs assembly by operating the robot.

  Patent Documents 1 to 4 disclose a copying mechanism for assembling.

Position error absorbing device, LB Autotech Co., Ltd., https: // www. bl-autotec. co. jp / FA / Easy Hand, Aikoku Alpha, http: // www. aikoku. co. jp / rh / Masakazu Fujii, Daisuke Shiogata, Hiroki Murakami, Mitsuharu Sonehara “Proposal of a safety system for human-industrial robot collaboration”, Proceeding of the 2008 JSME Conference on Robotics, and Nagano, Japan, Jun 5 2008

JP 2010-276431 A, “Copying mechanism” JP-A-61-284384, “Hand mechanism” JP-A-61-52943, “Pressing machine” JP 59-205293 A, “Handling device”

  In the automatic assembly by the robot of Non-Patent Document 1, in many cases, the passive mechanism can only follow a positional deviation of about several mm, and the workpiece is transported to the vicinity of the work object (several mm) in advance before assembly. Assembly is required. Therefore, when the position of the work object is indefinite, advanced measurement such as image processing of the work object must be performed. If a passive mechanism that can be assembled without measuring the work object is used, the number of axes of the passive mechanism needs to be increased, the amount of copying operation needs to be increased, and the apparatus becomes larger.

  The assembly by the assisting device of Non-Patent Document 2 is different from Non-Patent Document 1, and even when the position of the work object is indefinite, the work and the work object can be aligned by a human operation. However, since the operator receives the inertia of the workpiece during operation, it is difficult to align the posture of the workpiece. Therefore, in general, the posture of the workpiece is often fixed by a mechanical stopper or the like, but it is difficult to cope with a change in work target such as production of a multi-mixed product. If a passive mechanism is installed to eliminate the difficulty in workpiece posture alignment, and the workpiece and work object in which the posture is misaligned are to be assembled in a copying motion, the number of axes of the passive mechanism as in Non-Patent Document 1. Must be increased, which increases the passive mechanism.

  As in the case of Non-Patent Document 2, the assembly by the hand guide system of Non-Patent Document 3 allows the work and the work object to be aligned by human operation even when the position of the work object is indefinite. However, since the operator cannot sense the reaction force during assembly, collision (interference) or excessive push-in may occur, and the determination of assembly completion may vary depending on the operator.

  Similarly, in the copying mechanisms of Patent Documents 1 to 4, when using a passive mechanism that can be assembled without measuring a work object, as in Non-Patent Document 1, the number of axes of the passive mechanism increases, and the amount of copying motion However, there is a problem that the apparatus becomes large.

  The present invention has been developed to solve the above-described problems. That is, a first object of the present invention is a work assembling apparatus that can be configured with a small number of axes and can assemble a work on a work object by only a rough positioning of the work with respect to the work object and a simple pushing operation. Is to provide. Further, the second object of the present invention is to notify the operator of the completion of the assembly of the work with respect to the work object, and to prevent the collision or excessive push-in even when the assembly state is not visible. To provide an apparatus.

According to the present invention, it has a fitting member fitted to the work object, and the fitting member has a guide for guiding the fitting,
A hand movable in the robot area;
Attached to the hand, by the direction of the pushing operation assembly of the hand, and a passive scanning mechanism moves up and down direction orthogonal to the assembly direction the workpiece by the guide,
The work object has a positioning member orthogonal to the assembly direction and extending in the width direction,
The guide is a guide groove that guides the positioning member from an initial position to a completion position, and the guide groove has a vertical groove at the completion position;
The passive copying mechanism has a biasing device that biases the guide in a vertical direction toward the completion position,
Assembling the work to the work object by the pushing operation of the assembly direction, the workpiece assembly apparatus is provided, characterized in that.

According to an embodiment of the present invention, a stroke sensor that is provided in the passive copying mechanism and detects a displacement of a workpiece;
An assembly determination unit that detects completion of assembly of the workpiece with respect to the work object from the position of the hand and the displacement of the workpiece.

According to the configuration of the present invention, the passive copying mechanism attached to the hand has only one axis in the direction orthogonal to the assembling direction, so the number of axes of the movable part is small.
In addition, since the passive copying mechanism is designed to assemble the work on the work object by pushing the hand in the assembling direction, the work object can be obtained only by roughly aligning the work with the work object and performing a simple pushing operation. Work can be assembled to objects.

Further, according to the embodiment of the present invention, the completion of the assembly of the work with respect to the work object can be detected from the position of the hand and the displacement of the work by the stroke sensor and the assembly determination unit. The completion of the assembly can be notified to the operator, and even when the assembled state cannot be seen, it is possible to prevent collision and excessive push-in, and to stabilize the quality and improve the work efficiency.

It is a top view of the workpiece | work assembly apparatus of 1st Embodiment of this invention. FIG. 2 is a partial side view of the apparatus of FIG. 1. It is a block diagram of the passive mechanism of FIG. It is a block diagram of the passive copying mechanism of FIG. It is a system block diagram of the apparatus of FIG. It is explanatory drawing of an assembly | attachment determination part. It is a schematic diagram of the workpiece | work assembly apparatus of 2nd Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

FIG. 1 is a plan view of a work assembling apparatus according to a first embodiment of the present invention.
In this embodiment, the work assembling apparatus 10 is a hand guide apparatus for assembling the work 3 to the work object 2 moving on the line 1. The line 1 means a transfer line that continuously moves the work object 2 such as an assembly line, a picking line, or a processing line.

Line 1 is a line for assembling a work 3 (a module such as an instrument panel in this example) to a work object 2 (in this example, a car body), and the work object 2 is to the left (with a predetermined speed) In the figure) it is designed to move continuously. The predetermined speed may be constant or may vary.
The line 1 has a transport device (not shown) that transports the work object 2 along a predetermined trajectory. The predetermined trajectory is a preset trajectory.
The conveyor device may be a belt conveyor, a roller conveyor, a slat conveyor, a suspended chain conveyor, or the like as long as it can convey the work object 2 while maintaining its posture.

  The work object 2 (vehicle body) is provided with an opening (a door part of the vehicle body), and the workpiece 3 can be inserted into the vehicle through the opening. In this figure, reference numeral 4 denotes a robot area safety fence for partitioning a robot area 4a to which a hand mounting portion (a terminal portion 14a described later) of the robot 16 moves, and reference numeral 5 denotes a human area safety fence for partitioning the transfer device.

  In FIG. 1, the workpiece assembly apparatus 10 includes a passive copying mechanism 12, a hand 14, a robot 16, an operation panel 18, and a robot control apparatus 20.

  In this example, the hand 14 is an elongated member having the passive copying mechanism 12 at the distal end portion, and in this example, the hand 14 is positioned substantially horizontally. The hand 14 has such a length that the operation panel 18 protrudes from the work object 2 to the opposite side of the robot 16 when the work 3 is assembled to the work object 2.

The robot 16 is an articulated robot in this example, and cantilever-supports the end portion 14a (upper end in FIG. 1) of the hand 14, and is configured to be able to move the end portion 14a within the robot area 4a. The robot area 4a partially overlaps with the transfer device in order to assemble the workpiece 3 on the work target 2.
The robot 16 is not limited to an articulated robot, and may be another known robot.

In this example, the operation panel 18 is provided at the front end portion (lower end portion in FIG. 1) of the hand 14, and a person 6 (for example, a worker) is projected from the work object 2 to the opposite side of the robot 16 by the person 6 (for example, a worker). Is manually operated to operate translation of the hand 14 (movement in the direction of three orthogonal axes).
The operation panel 18 is not limited to this example, and may be an operation panel that operates the robot 16 in a wireless or wired manner.

The robot control device 20 controls the robot 16. The robot control device 20 has a line calibration function that automatically corrects the posture or posture and position of the hand 14 according to the posture of the line 1.
This line calibration function has a distortion measurement function for measuring the distortion amount of the line 1 (conveying device) and a correction function for correcting the posture of the hand 14 in real time according to the measured distortion amount.
The correction function is not limited to posture correction, and may include posture and position correction.

  With this configuration, since the posture of the workpiece 3 is automatically determined by the robot 16 at the time of assembly, the workpiece 3 and the work object 2 can be assembled even with a passive mechanism (described later) with a small number of axes.

FIG. 2 is a partial side view of the apparatus of FIG.
In this figure, the work assembling apparatus 10 has a fitting member 24 fitted to the work object 2, and the fitting portion 24 has a guide 24a (see FIG. 3) for guiding the fitting. Work 3 is targeted.
The workpiece assembly apparatus 10 includes the above-described hand 14 that can move in the robot area 4 a and the passive copying mechanism 12 attached to the hand 14.
The passive copying mechanism 12 is configured to move the workpiece 3 in a direction orthogonal to the assembling direction by the guide 24a when the hand 14 is pushed into the work object 2 in the assembling direction. In this example, the assembly direction 7 of the hand 14 is the moving direction of the line 1 (y direction in FIG. 1).

FIG. 3 is a configuration diagram of the fitting member 24 of FIG.
As shown in FIGS. 2 and 3, in this example, the workpiece assembling apparatus 10 includes a work object 2 having a positioning member 23 that is orthogonal to the assembling direction and extends in the width direction, and a guide 24a is a positioning member 23. The positioning member 23 is fixed to the work object 2 and is provided in a width direction (x direction in the figure) perpendicular to the pushing direction 7. Extend to. In this example, the positioning member 23 is a horizontal member having a circular cross section.

The fitting member 24 is fixed to the work 3 and is configured to be passively movable in a direction perpendicular to the assembly direction (in this example, the vertical direction). The fitting member 24 has a continuous guide groove 24 a that guides the positioning member 23 from the initial position A to the completion position B.
In this example, the guide groove 24a includes an inclined groove 25b extending obliquely downward from a recess 25a provided on the front surface of the fitting member 24, a horizontal groove 25c extending horizontally rearward from the lower end of the inclined groove 25b, and a horizontal groove. The vertical groove 25d extends upward from the rear end of 25c.

The initial position A is in the recess 25a. The approximate positioning of the workpiece 3 with respect to the work object 2 is performed by positioning the passive copying mechanism 12 so that the positioning member 23 is positioned in the recess 25a.
The completion position B is in the vertical groove 25d. The height of the completion position B in the vertical groove 25d is positioned by an urging device 36 described later.

FIG. 4 is a configuration diagram of the passive copying mechanism 12 of FIG.
In this figure, the passive copying mechanism 12 is attached to the hand 14 and includes a gripper 32, a linear guide 34, an urging device 36, and a stroke sensor 38, and a direction perpendicular to the assembly direction of the workpiece 3 (in this example, the up and down direction). Support in a movable manner in the direction).

The gripper 32 holds the workpiece 3 so as to be openable. The linear guide 34 is provided on the hand 14 and guides the gripper 32 so as to be movable in a direction orthogonal to the assembly direction (in this example, the vertical direction). The biasing device 36 is a biasing spring provided between the hand 14 and the gripper 32, and biases the gripper 32 toward the completion position B in a direction perpendicular to the assembly direction (in this example, the vertical direction). .
The stroke sensor 38 is provided in the hand 14 and detects the displacement (height change in this example) of the workpiece 3.

FIG. 5 is a system configuration diagram of the apparatus of FIG.
In this figure, the operation panel 18 has an operation input unit 18a and an operation state display lamp 18b. The robot control device 20 includes an assembly determination unit 20a and a command unit 20b.

  With this configuration, the hand 14 outputs the hand position a to the robot control device 20, the stroke sensor 38 outputs the height change (displacement amount b) of the workpiece 3 to the robot control device 20, and the assembly determination unit 20 a The assembly completion signal c is output to the command unit 20b, the command unit 20b outputs the assembly completion signal c to the operation state display lamp 18b, and the operation input unit 18a sends a workpiece release command d to the command unit 20b. The command unit 20b outputs a workpiece release signal e to the gripper 32.

FIG. 6 is an explanatory diagram of the assembly determination unit 20a.
In this figure, (A) shows the start of assembly, and (B) shows that assembly is in progress.
“At the start of assembly” means that the positioning member 23 and the fitting member 24 are in contact with each other. “Assembly” means that the passive copying mechanism 12 is operated so that the positioning member 23 follows the fitting member 24. It means when you are.

In FIG. 6, ΣR is a robot coordinate system, ΣH is a hand coordinate system, and ΣW is a work coordinate system.
Hereinafter, an assembly completion determination method by the assembly determination unit 20a will be described.

(1) The position P _r (0) of the positioning member 23 at the time t = 0 when the positioning member 23 and the fitting member 24 are in contact with the hand position P _H (0) at the time of contact (t = 0), Using the displacement L (0) of the fitting member 24 at the time of contact and the initial position A of the fitting member 24 as seen from the workpiece coordinate system ΣW, the equation (1) can be used.
P _r (0) = P _H (0) + L (0) + A (1)

(2) When the positioning member 23 is stopped as viewed from the robot coordinate system ΣR, the position Pr (t) of the positioning member 23 at time t is expressed by equation (2) as in equation (1).
P _r (t) = P _H (t) + L (t) + C (t) (2)

When the positioning member 23 is stopped, P _r (t) = P _r (0) (2a), and the position C (t of the positioning member 23 viewed from the workpiece coordinate system ΣW is obtained from the equation (2a). ) Can be calculated from equation (3).
P _H (t) + L (t) + C (t) = P _H (0) + L (0) + A
⇒ C (t) = P _H (0) + L (0) + A− (P _H (t) + L (t)) (3)

When the positioning member 23 is moving at the speed V, C (t) is expressed by Equation (4).
P _r (t) = P _r (0) + V · t
⇒ C (t) = P _H (0) + L (0) + A− (P _H (t) + L (t)) + V · t (4)

(3) Assembly completion determination By comparing the completion position B with Expression (3) or Expression (4), assembly completion can be determined.
Here, if the allowable error at the completion position B is ΔD (Δdx, Δdy, Δdz) and arranged for each x, y, z component, it can be determined that the assembly is completed when the condition of Expression (5) is satisfied.
−Δdx <(C (t) −B) _x <+ Δdx
−Δdy <(C (t) −B) _y <+ Δdy
−Δdz <(C (t) −B) _z <+ Δdz (5)
Here, x, y, and z represent xyz components viewed from the work coordinate system.

  By providing the above-described assembly determination unit 20a, it is possible to detect the completion of assembly of the workpiece 3 with respect to the work object 2 from the position of the hand 14 and the displacement of the workpiece 3 (height change in this example).

7A and 7B are schematic views of a workpiece assembling apparatus according to a second embodiment of the present invention, in which FIG. 7A is an overall perspective view, and FIG.
7A and 7B, the fitting member 24 described above is a slit hole 124, and the positioning member 23 is a pin 123.
The pin 123 has a tapered surface 123a that engages with the slit hole 124 and guides the workpiece 3 from the initial position A to the completion position B, and a latch surface 123b that prevents the slit 3 from coming off at the completion position B.

According to the apparatus of the present invention described above, the passive copying mechanism 12 attached to the hand 14 has only one axis in the direction orthogonal to the assembling direction, so the number of axes of the movable part is small.
Further, since the passive copying mechanism 12 is configured to assemble the workpiece 3 onto the work object 2 by pushing operation of the hand 14 in the assembling direction, the workpiece 3 is roughly aligned with the work object 2 and simply pushed. The workpiece 3 can be assembled to the work object 2 only by the operation.

  Further, according to the embodiment of the present invention, the stroke sensor 38 and the assembly determination unit 20a can detect the completion of the assembly of the workpiece 3 with respect to the work object 2 from the position of the hand 14 and the displacement of the workpiece 3. The operator can be notified of the completion of the assembly of the work 3 to the work object 2, and even when the assembled state is not visible, it can prevent bumping and over-pushing, stabilizing the quality and improving the efficiency of the work. Can be planned.

  In addition, this invention is not limited to embodiment mentioned above, Of course, a various change can be added in the range which does not deviate from the summary of this invention.

1 line, 2 work object (vehicle body),
3 work (instrument panel),
4 Robot area safety fence, 4a Robot area,
5 person area safety fence, 6 people, 7 pushing direction,
10 Work assembly device (hand guide device),
12 Passive copying mechanism,
14 hands, 14a end,
16 robots (articulated robots), 18 operation panels,
20 robot controller,
20a assembly determination unit, 20b command unit,
23 positioning member,
24 fitting member, 24a guide (guide groove),
25a recess, 25b inclined groove,
25c horizontal groove, 25d vertical groove,
32 grippers, 34 linear guides,
36 biasing device (biasing spring), 38 stroke sensor,
123 pins,
123a taper surface, 123b latch surface,
124 slit hole

Claims (6)

It has a fitting member that fits to the work object, and the fitting member has a guide that guides the fitting,
A hand movable in the robot area;
Attached to the hand, by the direction of the pushing operation assembly of the hand, and a passive scanning mechanism moves up and down direction orthogonal to the assembly direction the workpiece by the guide,
The work object has a positioning member orthogonal to the assembly direction and extending in the width direction,
The guide is a guide groove that guides the positioning member from an initial position to a completion position, and the guide groove has a vertical groove at the completion position;
The passive copying mechanism has a biasing device that biases the guide in a vertical direction toward the completion position,
Assembling the work to the work object by the pushing operation of the assembly direction, the workpiece assembly and wherein the. Provided in the passive scanning mechanism, and a stroke sensor for detecting the displacement of the workpiece,
Work assembly device according to claim 1, characterized in that and a assembling determination unit detects the completion assembly of the workpiece relative to the work object from the displacement of the the position of the hand work. Claim the passive scanning mechanism further, having a gripper which releasably gripping the workpiece, and a linear guide for movably guiding the gripper in a direction perpendicular to the assembly direction, characterized in that The work assembling apparatus according to 1 or 2. The work assembling apparatus according to any one of claims 1 to 3, further comprising a hand guide device or a remote operation device capable of operating the hand by a person. 5. A line calibration function that automatically corrects the hand to a posture in which the work and the work object can be assembled in accordance with a posture of the work object transfer device . The work assembly apparatus according to any one of the above. The line calibration function includes a distortion measurement function for measuring a distortion amount of the transport device, and a correction function for correcting the posture of the hand in real time according to the measured distortion amount. Item 6. The work assembling apparatus according to Item 5.