JPS6236614Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a screw lifting detection device for a screw tightening work unit that screws automatically supplied screws into a mating object using a driver bit, and an embodiment thereof will be described below with reference to the drawings. In Fig. 1, 1 is a screw tightening work unit, which has a support arm (not shown) attached to the tip of a work arm of an industrial robot (not shown), and a driver main body 2 is fixed to this support arm. has been done. A chuck holder 3 is fixed below the driver body 2, and a chuck 4 is further fixed to the chuck holder 3. A pair of chuck claws 5, 5 are held at the tip of the chuck 4 so as to be openable and closable.
The screws supplied through the screw guide sleeve 6 rotatably held by the chuck 4 are held by the chuck pawls 5.

On the other hand, the driver main body 2 also serves as a cylinder outer cylinder, and a bracket 7 that also serves as an upper cover is attached to this.
is fixed. A motor 8 as a rotational drive source is attached to the bracket 7 in parallel with the driver body 2 via a fixture 9, and its drive shaft 10 is rotatably held by the bracket 7 via a rotation stop detection mechanism 11. The rotating shaft 12 is connected to the rotary shaft 12. A spline shaft 14 rotatably held by the bracket 7 is connected to the rotating shaft 12 via a transmission mechanism 13. Further, this spline shaft 14 is arranged so that its axis coincides with the axis of the driver body 2.

A piston sleeve 15 that also serves as a piston is slidably guided in the driver body 2, and this piston sleeve 15 is connected to a first supply/discharge port 16.
It is configured to move up and down by alternately supplying and discharging air to and from the second supply/discharge port 17. Further, one end of the piston sleeve 15 is located inside the chuck holder 3, and the piston sleeve 15
is configured to slide also within the chuck holder 3. A guide lid 19 for guiding a sliding sleeve 18 is fixed to the piston sleeve 15, and the sliding sleeve 18 is elastically held by a spring 20 disposed within the piston sleeve 15.

A suction sleeve 21 having a stepped portion is fixed to the sliding sleeve 18.
A suction portion 22 is disposed at the tip of the chuck 4, and is configured to be located within the chuck 4. The stepped portion of the suction sleeve 21 is configured to slide while being guided by the chuck holder 3, and the stepped portion is provided with an air suction port 23 and an upper limit detection dog 24.
is attached, and the air suction port 23 and upper limit detection dog 24 are configured to move within vertical grooves 25 formed in the chuck holder 3, respectively. or,
The air suction port 23 communicates with the inside of the suction sleeve 21, and is configured so that the air inside the suction sleeve 21 is discharged. On the other hand, the upper limit detection dog 24 is arranged so as to be able to operate an upper limit detection switch 26 attached to the driver body 2.

A transmission shaft 27 is disposed on the piston sleeve 15, which moves up and down together with the piston sleeve 15 and is rotatably held relative to the piston sleeve 15. The transmission shaft 27 penetrates the bracket 7 and inserts a rotatably disposed spline shaft 14 therein, and is rotatable together with the spline shaft 14 and movable up and down with respect to the spline shaft 14. Further, one end of the transmission shaft 27 is attached to the suction sleeve 2.
1, and a driver shaft 29 disposed within the suction sleeve 21 is fixed to the lower end of the transmission shaft 27. A driver bit 30 is fixed to the driver shaft 29, and the driver bit 3
0 is located within the suction sleeve 21 and is configured to protrude from the suction sleeve 21 after screw tightening is started.

Next, the main parts of the present invention will be explained. As shown in FIG. 2, a detection rod 31 is held elastically and movably up and down through the stepped portion of the suction sleeve 21, as shown in FIG.
When the detection rod 5 is lowered, the guide lid 19 presses the detection rod 31 to lower it. On the other hand, the chuck holder 3 has a proximity switch 32.
is attached, and this attachment position is adjusted to a position where the position of the detection rod 31 can be detected when the driver bit 30 reliably screws the desired screw into the mating material. The proximity switch 32 and the detection rod 31
A screw floating detection device is constructed by the above.

In the above-mentioned screw tightening work unit, when one screw tightening work is completed, the screw is supplied to the chuck pawl 5 at the tip of the chuck 4, and the screw is supplied to the driver bit 30.
is held below. Thereafter, the next screw tightening operation is started, air is supplied from the first supply/discharge port 16, and the piston sleeve 15 is lowered. At the same time, the motor 8 rotates, and the rotation of the drive shaft 10 is transmitted to the driver bit 30 via the transmission mechanism 13, spline shaft 14, transmission shaft 27, and driver shaft 29.

Simultaneously with the lowering of the piston sleeve 15, the suction sleeve 21 also lowers, pushing out the screw guide sleeve 6, and the tip of the suction sleeve 21 comes into contact with the screw. At this time, from the air suction port 23 to the suction sleeve 2
Since the air in the suction sleeve 21 is suctioned, the screw is suctioned to the tip of the suction sleeve 21. In this state, the suction sleeve 21 further descends, and the chuck claws 5, 5
Push out and protrude outside the chuck 4. When the screw at the tip of the suction sleeve 21 reaches the pilot hole of the other object and the suction sleeve 21 stops descending, the driver bit 30 descends as the piston sleeve 15 descends, and the driver bit 30 screws in the screw.

When the screw is securely screwed into the mating material, the driver bit 30 descends to a predetermined position and stops rotating. At this time, as shown in FIG. 3, the piston sleeve 15 descends, and the guide lid 19 presses the detection rod 31, causing it to descend. Therefore, the detection rod 3
1 approaches the proximity switch 32, and the proximity switch 3
2 is activated, and the proximity switch 32 detects that the screw has been securely tightened.

If the screw is not securely screwed into the mating material and the driver bit 30 stops rotating, the piston sleeve 15 will not descend to a predetermined position. Therefore,
The detection rod 31 is not pressed by the guide lid 19 and does not approach the proximity switch 32. Therefore, since the proximity switch 32 does not operate, the detection timing for screw floating detection is determined by, for example, detecting a signal from the rotation stop detection mechanism 11.
Screw lifting can be detected.

As explained above, the present invention has an elevating means built into the driver body to raise and lower the driver bit, and a detection switch is attached to the chuck holder at a fixed position to detect the amount of movement of the elevating means. This method has advantages such as not only being able to detect poor tightening such as screw lifting, but also having an extremely simple configuration and being able to provide an inexpensive screw tightening state detection device. Further, the present invention has the advantage that even if the type of screw is changed, it is only necessary to replace the detection rod with one of an appropriate length, and there is no need to adjust the mounting position of the detection switch.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the present invention, FIG. 2 is a cross-sectional view of the main parts of the present invention, and FIG. 3 is an explanatory diagram of the operation of the main parts of the present invention. 1...Screw tightening work unit, 2...Driver body, 3...Chuck holder, 4...Chuck,
5...Chuck pawl, 6...Screw guide sleeve, 7
... Bracket, 8 ... Motor, 9 ... Mounting tool,
10... Drive shaft, 11... Rotation stop detection mechanism, 1
2... Rotating shaft, 13... Transmission mechanism, 14... Spline shaft, 15... Piston sleeve, 1
6...First supply/discharge port, 17...Second supply/discharge port, 18...
...Sliding sleeve, 19...Guide lid, 20...Spring, 21...Suction sleeve, 22...Suction part, 2
3... Air suction port, 24... Upper limit detection dog, 25
...Vertical groove, 26... Upper limit detection switch, 27...
Transmission shaft, 29...driver shaft, 30...driver bit, 31...detection rod, 32...proximity switch.

Claims (1)

[Claims for Utility Model Registration] A rotary drive source is arranged in parallel to the driver body 2, and a chuck holder 3 is attached below the driver body 2, and the suction sleeve 21 and the driver bit 30 are moved by moving the piston sleeve 15 into the chuck holder 3. In the screw tightening work unit in which the suction sleeve 21 is arranged movably and integrally with the suction sleeve 21, the suction sleeve 21 is provided with a step, and the detection rod 31 is movably and elastically held in the step, while
A screw floating detection device characterized in that a switch for detecting the approach of a detection rod 31 is attached to the chuck holder 3, and the detection rod 31 can be pressed by movement of a piston sleeve.