JPH06270026A - Screw tightening - Google Patents

Abstract

PURPOSE:To permit the screw tightening of a work on an obstcle or a narrow part, by installing a screw tightening bit in a suction pipe for sucking a screw and stopping a screw tightening head at a prescribed temporary point during the start of the screwing-in operation from an upper limit. CONSTITUTION:As for a screw tightening robot, a screw tightening bit 15 is directly connected with the output shaft of a motor-driven driver 14 for screw tightening, and a suction pipe 16 which is directly connected with a vacuum pipe 17 is provided so that the bit 15 is built in. The vacuum pipe 17 is elastically supported on a head base 20 through a suction spring 19, and freely fixed in an electrically turned-ON/OFF state by a chuck 18. In the application to a step difference work surface, a screw tightening head is allowed to stop at a prescribed temporary point during the start of the screwing operation from an upper limit, and the chuck 18 is operated at the stop position, and the suction pipe 16 is fixed at a previously set height, and then the screw is tightened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw tightening method for an industrial screw tightening robot.

[0002]

2. Description of the Related Art In recent years, demand for automation has been increasing in manufacturing plants due to 24-hour operation and lack of manpower.
We provide industrial screw tightening robots as a means of automating manufacturing plants. Hereinafter, a conventional industrial screw tightening robot will be described with reference to the drawings.

FIG. 8 shows the structure of a conventional industrial screw tightening robot. In FIG. 8, 1 is an electric screwdriver for screw tightening, 2 is a screw tightening bit directly connected to the output shaft of the electric screwdriver, 3 is an adsorption pipe for adsorbing the screw because the inner diameter varies depending on the head diameter of the screw, and 4 is an adsorption Vacuum pipe directly connected to the pipe, 5 is a stopper that fixes the vacuum pipe, 6 is an absorption spring that supports the vacuum pipe, 7 is a head base that fixes an electric screwdriver, 8 is an industrial screw tightening robot Z axis ball screw, and 9 is a head base. And a connecting bracket 10 for interlocking the ball screw with each other is a Y-axis of the robot. The operation of the industrial screw tightening robot configured as described above will be described below with reference to the operation flowchart of FIG.

When the industrial screw tightening robot starts, the X axis and Y axis not including the screw tightening direction are positioned at the screw tightening point. Next, it is determined whether the catcher under the suction pipe has a screw, and if there is a screw, the suction valve is operated to lower the Z axis. When the Z axis reaches the designated point, it is determined whether the screw tightening is completed. If the screw floats above the work surface, a screw tightening error will occur. The method for detecting screw floating is determined by the positional relationship between the screw tightening bit and the suction pipe.

The state of the final screw tightening is shown in FIGS.
It is as shown in 1. At this time, if the suction pipe is not desired to contact the work surface, the suction pipe 12 is fixed by the stopper 13.

[0006]

However, in the above-described structure and screw tightening operation, if there is a step on the work surface as shown in FIGS. 10 and 11, the suction pipe must be brought into contact with the work surface and the work surface and the suction pipe. The distance from and becomes different. At this time, since the positional relationship between the screw tightening bit and the suction pipe is naturally different, there is a problem that the screw floating detection is impossible.

Further, when there is an obstacle such as a lead wire on the screw tightening point, there is a problem that the screw tightening operation cannot be directly performed from above.

[0008]

In order to solve the above problems, the present invention provides a two-step screw tightening operation by adding a function of stopping at an arbitrary point while starting screwing from the screw tightening head upper limit.

Further, it is electrically turned ON for fixing the suction pipe.
-Provide a stopper that can be turned off.

[0010]

With the construction and operation as described above, the present invention makes it possible to specify the screw tightening bit and the suction pipe independently of each other, and to tighten the suction pipe non-contact screw tightening on the stepped work surface. Can be realized.

Further, by fixing the positional relationship between the screw tightening bit and the suction pipe, it becomes possible to detect the screw floating at all points.

In addition to this, by stopping midway between the screw tightening head origin and the screw tightening point, it is possible to tighten the screw on an obstacle or a narrow portion on the work surface.

[0013]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of an industrial screw tightening robot of this embodiment. In FIG. 1, 14 is an electric screwdriver for screw tightening, 15 is a screw tightening bit directly connected to the output shaft of the electric screwdriver, 16 is a suction pipe for sucking the screw depending on the screw head diameter, and 17 is directly connected to the suction pipe. The vacuum pipe, 18 is a chuck for electrically turning on and off the vacuum pipe and fixing it, 19 is an absorption spring for supporting the vacuum pipe, 20 is a head base for fixing an electric screwdriver, 21 is a Z axis of an industrial screw tightening robot. A ball screw, 22 is a connecting bracket for interlocking the head base and the ball screw, and 23 is a Y axis of an industrial screw tightening robot. Regarding the industrial screw tightening robot configured as described above, its operation will be described below with reference to the operation flowchart of FIG. 2 with reference to FIGS. 3, 4, 5, 6, and 7.

The screw tightening operation when there is an obstacle such as a lead wire on the screw tightening point on the work surface will be described with reference to FIGS. 3, 4 and 5.

When the industrial screw tightening robot starts, the X-axis and Y-axis not including the screw tightening direction are lead wires 25.
Position at the horizontal stop point. Then, FIG. 3 shows that the Z-axis is lowered to the temporary stop point by sucking the screw. Next, as shown in Fig. 4, X does not include the screw tightening direction from the temporary stop point.
Move the axis and Y-axis again to the screw tightening point. Finally, as shown in FIG. 5, the Z axis is moved again to the screw tightening point to complete the screw tightening.

Next, there is a step on the work surface, and the suction pipe 2
6 and 7 show a case where the screw 6 is tightened without coming into contact with the work surface. When the industrial screw tightening robot starts, the X axis and Y axis not including the screw tightening direction are positioned at the temporary stop point and the Z axis is lowered to the temporary stop point. Then, after confirming that the X axis, the Y axis, and the Z axis are positioned at the temporary stop points, the suction pipe 26 is fixed by the electric fixing chuck 27 at a predetermined height according to the state of the work surface. After that, since the X-axis and the Y-axis have the same position data as the temporary stop point and the screw tightening point, the Z axis is lowered to the screw tightening point to complete the screw tightening. By performing such an operation, the positional relationship between the work surface and the suction pipe can be kept constant regardless of the step of the work surface. In other words, it is possible to detect the screw lift after tightening the screw at all points.

If the suction pipe is fixed at the temporary stop point on the side of the lead wire as described above, it is also possible to tighten the screw without contacting the suction pipe with the work surface as shown in FIG.

[0019]

As described above, according to the present invention, the screw can be tightened to an obstacle or a narrow portion on the work surface by enabling the temporary stop at an arbitrary point during the screw tightening operation. In addition, since the suction pipe can be fixed at a preset height at the temporary stop point, the suction pipe can be screwed to the stepped work surface without contact, and screw lift can be detected at all points. It was

With this operation, more precise screw tightening is possible.

[Brief description of drawings]

FIG. 1 is a side view of a screw tightening head portion of an industrial screw tightening robot according to an embodiment of the present invention.

FIG. 2 is an operation flowchart of the industrial screw tightening robot of the embodiment.

FIG. 3 is a side view of a partial cross section of a screw tightening head portion showing a lead wire avoiding operation.

FIG. 4 is a side view of a partial cross section of a screw tightening head portion showing a lead wire avoiding operation.

FIG. 5 is a side view of a partial cross section of a screw tightening head portion showing a lead wire avoiding operation.

FIG. 6 is a side view of a partial cross section of a screw tightening head portion showing a screw tightening operation for a work having a step.

FIG. 7 is a side view of a partial cross section of a screw tightening head portion showing a screw tightening operation for a work having a step.

FIG. 8 is a side view of a screw tightening head portion of a conventional industrial screw tightening robot.

FIG. 9 is an operation flowchart of a conventional industrial screw tightening robot.

FIG. 10 is a side view of a partial cross section of a screw tightening head portion showing a screw tightening operation for a conventional stepped work.

FIG. 11 is a side view of a partial cross section of a screw tightening head portion showing a screw tightening operation for a conventional stepped work.

[Explanation of symbols]

 1,14 Screw tightening electric screwdriver 2,11,15 Screw tightening bit 3,12,16,24,26 Vacuum suction pipe 4,17 Vacuum pipe 5,13 Vacuum pipe fixing stopper 6,19 Vacuum pipe absorption spring 7,20 Head base 8,21 Z-axis ball screw 9,22 Connection bracket 10,23 Industrial screw tightening robot Y-axis 18,27 Electric fixed chuck 25 Lead wire

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shingo Azumi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A suction pipe for sucking a screw, a screw tightening bit configured to be movable up and down in the screw tightening direction in the suction pipe and fitted with the screw, and a screw through the screw tightening bit. In the screw tightening method of an industrial screw tightening robot having an electric screwdriver that is configured to move up and down as a whole, in a screw tightening method for an industrial screw tightening robot, a predetermined time point between the screw tightening head upper limit and the screwing operation is started. And a step of fixing the suction pipe to a preset height at the stop position. 2. A suction pipe for sucking a screw, a screw tightening bit configured to be movable up and down in the screw tightening direction in the suction pipe, and fitted with the screw, and a screw through the screw tightening bit. A screw tightening method for an industrial screw tightening robot having a screw tightening head configured to be movable up and down as a whole, with an electric screwdriver that tightens the screwdriver, and stops at an arbitrary point while starting screwing from the upper limit of the screw tightening head. A screw tightening method comprising a step, a step of performing a predetermined operation by an external signal at a stop position, a step of moving in a two-dimensional direction that does not include a screw tightening direction thereafter, and a step of tightening the screw thereafter.