JPH0785858B2 - Work tool pitch adjustment device and screw tightening robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to insertion, removal, and
The present invention relates to a work tool pitch adjusting device that adjusts the pitch between two work tools attached to the tip of a highly versatile industrial robot that is used for assembly and the like, and a screw tightening robot equipped with the same.

[Prior Art] and “Problems to be Solved by the Invention” Recently, in product assembly work, a work tool is moved to a predetermined work position, and control is performed so that the predetermined work is performed at that position. There are many teaching playback type robots that have been used, and various working units that are attached to the tip of the robot have been developed as their use progresses. However, since it is very excellent in that it can flexibly deal with this, a work unit attached to this is required to be versatile enough to deal with various works.

The present invention was invented in accordance with the above-mentioned demand, and a work tool pitch adjusting device that can be used also in a stand-alone type mechanical device in which the pitch between two work tools can be arbitrarily adjusted, and a provision thereof It is intended to provide a screw tightening robot.

[Means for Solving the Problems] In order to solve the above problems, a pivot shaft that penetrates the mounting portion and stands upright at a predetermined interval is arranged.
A support portion and a locking portion that rotate about the pivot shaft are attached to each of the swivel shafts, and a work tool is fixed to each of the support portions.

A motor having a drive shaft extending in the horizontal direction is attached to the attaching portion, and a ball screw shaft extending in the same direction and rotating integrally is connected to the drive shaft of the motor. A ball screw bearing is attached to the ball screw shaft, and the locking portion is rotatably connected to the ball screw bearing along with the movement of the ball screw bearing, and the movement of the ball screw bearing is pivoted. It is configured to convert into rotational motion of.

Further, the housing of the revolving device is fixed to the tip of the robot, and an arm that revolves on a horizontal plane in response to rotation of a motor is arranged on the housing, while this arm serves as the mounting portion and a work tool is a screw tightening tool. May be

[Operation] In the above device, when the motor horizontally mounted on the mounting portion rotates by a predetermined rotation amount, the ball screw shaft rotates accordingly, and the ball screw bearing moves horizontally. In response to the movement of the ball screw bearing, the locking portion rotates about the axis of the turning shaft as a fulcrum. With the turning of the turning shaft, the turning shaft and the supporting part turn in opposite directions. By the swinging motion of the support part, the pitch between the work tools attached to each support part is arbitrarily changed,
It is possible to provide a device having an arbitrary work tool pitch.

Also, if the work tool is a screw tightening tool and the arm of the turning device attached to the tip of the robot is used as the attachment part, the work positions of the robot are sequentially selected and every work position on the work is set in two places. You can select and perform screw tightening work, and in addition to the versatility of the robot itself, the versatility of this device can accommodate any work, and the work position on the work is set at any pitch. Also, it is possible to perform tightening work at every two places. For example, even in the tightening work in which the rubber packing is between the works, the tilt of the work that occurs during the tightening work with the single-axis screw tightening tool, etc. Does not occur at all and therefore does not affect the screw tightening torque at the opposite position at all and ensures the specified tightening at all tightening positions. It is possible to perform the work tightening torque.

Embodiments Embodiments will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 denotes a screw tightening robot, which is composed of a teaching playback type XY table.
A swivel device 2 is fixed to the tip of a part of the Y-table 1a of the screw tightening robot 1, and a drive shaft (not shown) is provided at the upper part of a housing 2a of the swivel device 2 so that the first part is provided. The motor 3 is fixed. An arm 4 extending in the horizontal direction is connected to the drive shaft of the first motor 3 via a speed reduction mechanism (not shown), so that the arm 4 swivels on a horizontal plane as the first motor 3 rotates. Is configured. The first motor 3 has a first
The encoder 3a is connected, and the rotation amount of the first motor 3 is detected, and the first motor 3 is feedback-controlled based on the rotation amount.

The arm 4 serves as a mounting portion for the work tool pitch adjusting device 5, and the work tool pitch adjusting device 5 has a second motor 6 fixed to a side surface of the arm 4 so as to extend horizontally. . Drive shaft of the second motor (not shown)
A ball screw shaft 7a forming a part of the orthogonal direction rotation switching mechanism 7 is rotatably arranged on the same center line. A second encoder 8 for detecting the rotation of the second motor 6 is connected to the second motor 6, and the rotation amount of the second motor 6 is detected and the second motor 6 is feedback-controlled from the rotation amount. ing. Further, a ball screw bearing 7b is screwed on the ball screw shaft 7a so as to be linearly reciprocally movable, and the ball screw bearing 7b is linearly reciprocally moved as the ball screw shaft 7a rotates. The ball screw bearing 7b has projecting portions 7c projecting on both sides thereof, and the projecting portion 7c is provided with a long hole 7d for engaging a pin 10b fixed to a locking portion 10a described later, Ball screw bearing 7b moves forward and backward to lock 10a
Is configured to be rotatable.

In addition, the arm 4 passes through it and stands upright on both sides of the ball screw shaft 7a with the ball screw shaft 7a interposed therebetween.
Are rotatably arranged, and support portions 10, 10 that rotate integrally with the swivel shafts 9, 9 are attached so as to extend in the horizontal direction. Locking portions 10a, 10a projecting from openings 4a, 4a formed on both sides of the arm 4 are fixed to the lower ends of the pivots 9, 9.
Moreover, a pin 10b that engages with an elongated hole 7d formed in the projecting portion 7c of the ball screw bearing 7b is fixed to the locking portions 10a, 10a, and the vertical rotation of the second motor 6 is locked. Part 10a
The orthogonal rotation switching mechanism is configured so that the rotation can be switched to the horizontal rotation.

A screw tightening tool 11, which is an example of a work tool, is attached to each of the support portions 10. (Hereinafter, one screw tightening tool 11 will be described.) This screw tightening tool 11 is a support part.
10 has a spline shaft 12 that extends in an upright direction and is fixed thereto, and the spline shaft 12 has upper brackets 13a located at both ends thereof and extending in a horizontal direction.
Lower brackets 13b are fixed, and cylinders 14 extending in an upright direction are fixed to the upper brackets 13a with their rods 14a facing downward. A driver base 15 is fitted to the spline shaft 12 so as to be movable only in the vertical direction. One end of the driver base 15 is connected to a rod 14a of the cylinder 14, and the driver base 15 is activated by the operation of the cylinder 14. Are configured to move. A screw tightening motor 17 is fixed to the driver base 15 via a motor base 16 with its drive shaft (not shown) facing downward, and the drive shaft (not shown) receives its rotation and rotates. A driver bit (not shown) is configured to rotate integrally. Further, a suction sleeve 18 is arranged around the driver bit so as to be able to retract along the driver bit, and the suction sleeve 18 is lowered by lowering the driver base 15.
When the tip of the abuts against a work (not shown), it is configured to retreat relative to the driver bit.
Further, a chuck unit 19 is attached to the lower bracket 13b below the driver bit and the suction sleeve 18, and the tips of these are located in the chuck unit 19 and are pierceable. . Further, the chuck unit 19 has a pair of openable and closable chuck claws 19a for holding a desired screw (not shown) on the moving path of the suction sleeve 18 and the driver bit, and the suction sleeve 18 and the driver bit pass therethrough. It is configured to be pushed open by.

In the above screw tightening robot, each table and the turning device 2 are determined from two desired screw tightening positions and the distance between them.
After the command value is given to and these positioning is completed,
A rotation command value corresponding to the distance between the two screw tightening positions is given to the second motor 6, and the second motor 6 rotates by a predetermined rotation amount. The vertical rotation of the second motor 6 is converted into the linear movement distance of the ball screw bearing 7b via the ball screw shaft 7a, and further converted into the horizontal rotation of the locking portion 10a. Therefore, the swivel shaft 9 also rotates integrally, and the supporting portions 10 fixed to the upper ends thereof swivel in the opposite directions, that is, in the opening directions on the horizontal plane. Along with the turning of the support portion 10, the screw tightening tool 11 at the tip also turns in the opening direction, and the pitch between the driver bits reaches a predetermined distance as shown in FIGS. 3 and 4. Therefore, each of the driver bits matches the desired screw tightening position, and the positioning of the two screw tightening tools 11, 11 is completed.

After that, the cylinder 14 operates, the screw tightening motor 17 rotates, sucks the screw held by the chuck claw 19a into the suction sleeve 18, and then opens the chuck claw 19a to open the screw at a predetermined screw tightening position. Can be tightened.

In the screw tightening robot 1, since only the second motor 6 is used as a motor for driving each of the swivel shafts 9 in the work tool pitch adjusting device 5, the pitch between the work tools as a working unit of the screw tightening robot 1 is increased. The adjusting device 5 can be made smaller and lighter, and the screw tightening work can be performed in a narrower position, and the work tool pitch adjusting device 5 can be used.
It is also possible to reduce the moment acting on the arm of the screw tightening robot 1 with the reduction in weight.

By operating the screw tightening robot 1 as described above,
By moving the screw tightening tool 11 on the stand to a predetermined position in sequence and then positioning the two screw tightening positions, it is possible to perform screw tightening work at every two screw tightening positions on the workpiece. Even if there are many screw tightening positions on the work, the screw tightening work can be completed in a short time.

[Effects of the Invention] As described above, the present invention is configured so that the pitch between two work tools can be changed arbitrarily, so that even if the type of work is changed, work can be performed easily in response to this. There is an advantage that the pitch between tools can be adjusted and an extremely versatile device can be provided. Further, the present invention can be used as a tip unit of a robot, and if a screw tightening tool is used as a work tool, every work position on a work can be surely tightened at every two positions, and any work can be performed. Not only can we provide a highly versatile screw tightening robot that can perform screw tightening work correspondingly, but it is also possible to perform tightening work sequentially by selecting two opposing work positions on the work. Even if screw tightening work is performed with a rubber packing etc. sandwiched between them, there is an advantage that the work does not warp and the tightening work can be reliably performed with the desired tightening torque. In addition, a ball screw bearing is movably provided on the ball screw shaft, and a locking portion that rotates by the movement of the ball screw bearing is integrally attached to each swivel shaft. There is an advantage that only one motor is required to rotate the work tool, and therefore the work tool pitch adjusting device can be controlled very easily, and the work tool pitch adjusting device can be downsized, resulting in a narrower position. It is possible to perform the work of, and due to the weight reduction due to the miniaturization, it is possible to reduce the moment acting on the arm when the work tool pitch adjustment device is attached to the arm tip of the screw tightening robot or the like, There are advantages that the operation speed of the screw tightening robot or the like can be improved, work can be performed quickly, and the followability at the time of stop can be improved to improve the positioning accuracy.

A worm wheel mechanism may be used as the orthogonal direction rotation switching mechanism, or linear movement of the ball screw bearing may be converted into rotational movement by a rack and pinion mechanism.
Also, the screw tightening tool extends in the same direction as the support part,
The minimum work tool pitch may be reduced by arranging them so as to cross each other.

[Brief description of drawings]

FIG. 1 is a side view of the main part of an example of the present invention, FIG. 2 is a plan view of the main part of FIG. 1, FIG. 3 is a front view of the main part during operation of the present invention, and FIG. It is a partially cutaway plan view. 1 ... Screw tightening robot, 1a ... Y table, 2 ... swivel device, 2a ... housing, 3 ... first motor, 3a ... first encoder, 4 ... arm, 4a ... opening, 5 …… Pitch adjuster between work tools, ……………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… , 8 ...... second encoder, 9 ... swivel axis, 10 ... supporting part, 10a ... locking part, 10b ... pin, 11 ... screw tightening tool, 12 ... spline shaft, 13a ... upper bracket , 13b …… Lower bracket, 14 …… Cylinder, 14a …… Rod, 15 …… Driver stand, 16 …… Motor stand, 17 …… Screw tightening motor, 18 …… Suction sleeve, 19 …… Chuck unit, 19a… … Chuck claws,

Claims (2)

[Claims] 1. A swivel shaft which passes through the mounting part and stands upright at a predetermined interval is arranged in the mounting part, and a supporting part and a locking part which rotate about the swivel shaft are attached to each of the swivel shafts.
A work tool is attached to each of the support portions, and a motor having a drive shaft extending in the horizontal direction is attached to the attachment portion, and a ball screw shaft extends in the same direction and is rotatably connected to the drive shaft. A ball screw bearing movable along the screw shaft is attached to the screw shaft, and the engaging portion is rotatably connected to the ball screw bearing along with the movement of the ball screw bearing. Pitch adjusting device. 2. A housing of a revolving device is fixed to the tip of a robot, and an arm which reciprocates on a horizontal plane in response to rotation of a motor is arranged in the housing. The arm penetrates through the arm and has a predetermined interval. And an upright swivel shaft is arranged, and a supporting part and a locking part that rotate about the swivel shaft are attached to each of the swivel shafts, and a screwing tool is attached to each of the support parts, while extending horizontally in the arm. A motor having a drive shaft is attached, and a ball screw shaft extending in the same direction and integrally rotatably connected to the drive shaft, and a ball screw bearing movable along the ball screw shaft is attached to the ball screw shaft.
A screw tightening robot, wherein the locking portion is rotatably connected to the ball screw bearing along with movement of the ball screw bearing.