JPH0613797Y2 - Guide device for screw tightening robot - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is fixed to an arm that can be swiveled around a column, and screw parts such as screws and bolts that are supplied in each work cycle are preset in the work. The present invention relates to a guide device that guides a driver unit in a screw tightening robot that tightens at a screw tightening position.

[Conventional technology]

Various types of screw tightening robots in which the driver unit for tightening screws, bolts and the like are fixed to the tip of the arm have been considered in the past, and generally, the one shown in FIG. 6 is considered. ing. This is disclosed in Japanese Patent Laid-Open No. 61-101313, and a screw supply unit 140 that stores a large amount of screws is fixed to the arm 101. The screws stored therein are aligned and supplied to the front catcher 120, and one screw is held by the catcher 120 for each work cycle. A guide shaft 110 supporting a driver unit 130 is fixed to the arm 101 upright, and a piston cylinder 150 for moving the driver unit 130 up and down is fixed to the guide shaft 110. Moreover, a slide shaft 160 is fixed to the arm 101 in parallel with the guide shaft 110, and the driver unit 130 is guided along the slide shaft 160. Then, when the screw is held by the catcher 120, the upper driver unit 130 descends, the screw in the catcher 120 is sucked and held by the tip of the driver unit 130, and the screw is tightened to the work.

[Problems to be solved by the invention]

As described above, since the conventional driver unit mounted on the industrial robot descends along the slide shaft by the piston cylinder mounted on the guide shaft, the whole becomes heavy, and therefore, the arm unit In the positioning work at a predetermined position, the inertial force of the arm becomes large, and it takes time to position the arm with respect to the work position, and it extends parallel to the guide shaft separately from it.
A book slide shaft is required, and the distance from the guide shaft to the center of the driver unit increases, which also causes an increase in inertial force during arm rotation, and sometimes the guide shaft rotates with respect to the arm. There are various problems such as loose mounting of the guide shaft.

[Means for solving problems]

The present invention is intended to solve the above-mentioned problems, and is provided with an arm that can be positioned at a position taught in advance, and a guide shaft is fixed to the tip of this arm so as to stand upright on the arm. In a screw tightening robot in which a support member slidable in the axial direction is guided to the support member, and a driver unit is attached to the support member, the guide shaft is fixed as a single unit to the arm and
A spline groove or ridge is formed in the axial direction on the outer circumference of the arm, and a sliding member that engages with the spline groove or ridge of the guide shaft and slides along this is attached to the support member, and the support is further provided. A belt is connected to the member and rotates in parallel with the guide shaft in response to the rotation of a motor built in the arm.

[Action]

In the screw tightening robot, when the arm reaches the position taught in advance, the motor built in the arm rotates to rotate the belt by a predetermined amount. As a result, the support member is pulled down in the descending direction, but the support member is lowered by a predetermined distance along the spline groove or the ridge of the guide shaft by the action of the sliding member attached to the support member. Therefore, the driver unit attached to the support member can be lowered to perform a predetermined tightening operation at a predetermined position.
Moreover, during this time, the support member is merely descending directly along one guide shaft via the sliding member, but even if the driver unit receives an inertial force in the rotating direction during arm rotation, Alternatively, the rotation of the driver unit is surely restricted by the protrusion and the sliding member that engages with the protrusion.
Further, since the lifting and lowering of the driver unit is guided by only one guide shaft, not only the weight of the entire unit attached to the guide shaft can be reduced, but also the distance between the guide shaft added to the guide shaft and the center of the driver unit can be reduced. Becomes shorter,
The inertial force applied to the guide shaft in the rotating direction can be reduced, and the guide shaft is never loosely fixed to the arm.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. In FIGS. 1 and 5, reference numeral 1 denotes an arm of an industrial robot that can swivel around a column 2. A distal end of the arm 1 is a hollow shaft-shaped guide having a spline groove 10a formed in the outer peripheral axial direction. One shaft 10 is fixed upright.
A driven pulley 11 is disposed above the guide shaft 10, and the pulley 11 is rotatably supported by a guide member 13 which is supported at a height adjustable by a fixing member 12 fixed to the upper end of the guide shaft 10. It also serves as a tension pulley that adjusts the tension of the belt 14. A belt 14 is wound around the driven pulley 11 between the driven pulley 15 and a lower driving pulley 15.
A guide pulley 16 is arranged between the main driving pulley 15 and the driven pulley 11 to change the circulation direction of the belt 14.
Further, an idle pulley 17 is arranged on this belt 14.

Further, the driving pulley 15 and the guide pulley 16 are built in at the tip of the arm 1 of the industrial robot, and the driving pulley 15 is rotatable by a servo motor 18 built in the arm 1 via a reduction mechanism 19. The belt 14 is configured to be rotatable in parallel with the guide shaft. On the other hand, a nose that holds a screw 60 at the tip of the arm 1 for each work cycle and supports a pair of jaws 23, the tips of which are elastically biased and slidable in opposite directions.
A catcher base 21 to which 22 is attached is fixed, and the pair of jaws 23 and nose 22 constitutes a catcher 20.
Also, as shown in FIGS. 1 and 4, the guide shaft 10
A support member 31 fixed to a slide member 36 which can be moved up and down along this is attached to the slide member 36, and a ball 37 rolling on the spline groove 10a is engaged with the slide member 36 to guide the guide shaft 10. The movement in the circumferential direction is restricted. In this embodiment, the guide means is a plurality of spline-shaped grooves.
A ridge may be used instead of a. Further, as shown in FIG. 3, the support member 31 is integrally fixed to the belt 14.
A driver unit 30 having a motor (not shown) for rotating a driver bit 32 at the tip is fixed to the support member 31, and the driver bit 32 is rotatably and slidably incorporated in the driver unit 30. At the same time, a suction sleeve 33 that holds the screw 60 by suction is attached to the tip. As shown in FIG. 1, the tip of the suction sleeve 33 is slidably inserted into the nose 22 of the catcher 20, and the suction sleeve 33 is located at the center of a holding portion 23 a formed on the jaw 23. Have the same center as. Furthermore,
The guide shaft 10 also serves as a pipe for guiding the electric wires connected to the servo motor 18 and various sensors (not shown) built in the arm 1.

A slide cylinder 35 is inserted in a guide cylinder 34 fixed to the support member 31 and constituting the driver unit 30 so as to be slidable in the axial direction.
A piston cylinder (not shown) for moving the driver bit 32 up and down is built in 35.

Next, the operation of this embodiment will be described. When the arm 1 of the industrial robot moves to the work position of the work 61 which is taught in advance, the servo motor 18 subsequently operates. At this time, since one screw 60 has already been supplied and held by the holding portion 23a, the belt 14 is moved by the operation of the motor 18, and the driver unit 30 descends along the guide shaft 10. By the lowering of the driver unit 30, the suction sleeve 33 passes through the inside of the catcher 20, and the screw 60 is suction-held at the tip. Then, as shown in FIG. 2, the driver unit 30 descends in this state and reaches the work 61, and the lower limit of the driver 30 is that the suction sleeve 33 is the work 61 in advance.
The motor 18 is stopped at this position because it is set to stop immediately before it comes into contact with. At this time,
Since the driver bit 32 has already rotated, it continues to descend while rotating, and the screw 60 is fastened to the work 61.

In this way, the screw tightening work is completed. Subsequently, since the motor 18 rotates in the reverse direction, the belt 14 moves in the opposite direction, the driver unit 30 moves up, and the driver bit 32 also moves up in the suction sleeve 33 and returns to the original position. Then, the next screw 60 is again supplied to the catcher 20, and at the same time, the arm 1 is moved to the next working position, and the above operation is repeated.

Although the belt 14 is moved by using the servo motor 18 in this embodiment, a rotary positioning control motor such as a pulse motor may be used instead.

[Effect of device]

As is apparent from the above-described embodiments, the present invention has a single guide shaft that guides the lifting and lowering of the support member to which the driver unit is attached and is directly fixed to the arm, and the spline is axially provided on the outer periphery of the arm. While forming a groove or a ridge, a sliding member that engages with the spline groove or ridge of the guide shaft and slides along the groove is attached to the support member, and the support member has a motor built in an arm. The driver unit merely descends along one guide shaft because the belt that rotates and rotates in parallel with the guide shaft is connected. Even if an inertial force is applied, not only the rotation of the driver unit is surely restricted by the spline groove or the ridge and the sliding member engaging with the ridge,
The weight of the entire unit attached to the guide shaft can be reduced, the distance between the guide shaft added to the guide shaft and the center of the driver unit can be shortened, and the inertial force applied to the guide shaft in the rotating direction can be reduced. There is an advantage in that the fixation of is never loose.

[Brief description of drawings]

1 is a sectional front view showing an embodiment of the present invention, FIG. 2 is a sectional front view showing an operating state, FIG. 3 is an enlarged sectional side view of FIG. 1 excluding a driver, and FIG. 4 is a guide shaft. FIG. 5 is a schematic front view showing a relationship between an arm of an industrial robot and a driver unit, and FIG. 6 is a schematic front view showing a conventional example. 1 is an arm, 2 is a pillar, 10 is a guide shaft, 10a is a spline groove, 11 is a driven pulley, 12 is a fixed member, 13 is a guide member, 14 is a belt, 15 is a drive pulley, 16 is a guide pulley, and 17 is an idle. Pulley, 18 is a servo motor, 19 is a reduction mechanism, 20 is a catcher, 21 is a catcher stand, 22 is a nose, 23 is a jaw, 23a is a holding part, 30 is a driver unit, 31 is a supporting member, 32 is a driver bit, 33 Is a suction sleeve, 34 is a guide tube, 35 is a slide tube, 36 is a sliding member, 37 is a ball, 60 is a screw, 61 is a work,

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. An arm, which is movable to a position taught in advance, is provided, a guide shaft is fixed to the tip of the arm so as to stand upright, and a support member slidable in the axial direction is attached to the guide shaft. In the screw tightening robot in which the driver unit is attached to the support member, the guide unit is directly fixed to the arm with one guide shaft, and
A spline groove or ridge is formed in the axial direction on the outer circumference of the arm, and a sliding member that engages with the spline groove or ridge of the guide shaft and slides along this is attached to the support member, and the support is further provided. A guide device for a screw tightening robot, characterized in that a belt, which is rotated parallel to the guide shaft in response to rotation of a motor built in the arm, is connected to the member.