JPH068072A - Automatic feeder for nut - Google Patents

Abstract

PURPOSE:To vacuum-suck a nut positively in the desired attitude. CONSTITUTION:A single nut 8 is moved into a preset position 16 by the piston rod 13 of a cylinder 12, and a screw rod 19 is rotatory-driven from below and screwed with the nut 8b. In the state of thus holding the attitude of the nut 8b, the nut 8b is fitted into the fit-in recessed place 30 of a vacuum suction means 27. The screw rod 19 is then rotatory-driven in the reverse direction and removed from the nut 8b, and the nut 8b is brought into a nut fastening position by a vacuum suction means 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic nut feeder for automatically feeding nuts one by one to an automatic nut tightener or the like.

[0002]

2. Description of the Related Art Conventionally, nuts are aligned and supplied one by one, and each nut is individually sucked into a fitting recess 2 of a vacuum suction member 1 shown in FIG. 6 (1). , Prior art for moving to a desired location is known. The central hole 4 of the adsorption member 1 is connected to a vacuum source.

[0003]

The problem to be solved by the invention is shown in FIG.
In the prior art shown in FIG. 6, the nut 3 is not normally attracted to the fitting recess 2, and the nut 3 is erroneously attracted in the fitting recess 2 as shown in FIG. 6B. Is happening. If the nut 3 is attempted to be screwed into the threaded portion of the bolt in this state, the screw hole of the nut or the bolt to be screwed into the nut may be damaged, or the nut 3 may not be screwed. Occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic nut feeding device capable of securely sucking and feeding the nut in a desired posture.

[0005]

According to the present invention, there is provided means for moving a nut to a predetermined position and a screw rod provided below the nut at the predetermined position for rotating the screw rod. A nut automatic holding device comprising: a means for holding the nut; and a fitting recess into which the nut held by the nut holding means is fitted, and means for adsorbing the nut in the fitting recess. It is a supply device.

[0006]

According to the present invention, the nut moving means moves the nut to a predetermined position, and in this state, the screw rod is rotationally driven from below the nut to screw the screw rod into the nut. The nut is accurately maintained in a predetermined posture, and in this state, the nut can be accurately fitted into the fitting recess of the suction means. Therefore, the nut is not attracted in an undesired posture as described with reference to FIG. 6 (2) described above, and the subsequent screw tightening operation can be reliably performed.

[0007]

1 is a simplified sectional view of an embodiment of the present invention, and FIG. 2 is a plan view of the embodiment. On the base 6 provided at the fixed position, the nut aligning means 7 sequentially moves the individual nuts 8 one by one in the direction of the arrow 10 along the pair of guide protrusions 9. A pair of guide protrusions 11 are formed at right angles to this direction 10, and a nut indicated by reference numeral 8a is attached to the guide protrusions 11 in the direction of arrow 14 by a push rod 13 which is a piston rod of a double-acting pneumatic cylinder 12. The corner portion 42 is slidably moved along with it, and is moved until it comes into contact with the stopper 15. The nut thus abutting on the stopper 15 is indicated by reference numeral 8b.

FIG. 3 shows a state in which the flat surface 41 of the nut 8b contacts the stopper 15 and stops at a predetermined position 16. The nut 8b has a substantially hexagonal columnar outer shape, and a screw hole 17 is formed therein. Thickness d of nut 8b
1 is larger than the height h1 of the guide protrusion 11 and the stopper 15 (d1> h1).

Nut holding means 18 is provided below the base 6 at the predetermined position 16. The nut holding means 18 includes a screw rod 19 having a vertical axis perpendicular to the horizontal base 6 and a motor 20 for driving the screw rod 19 in forward and reverse directions.
1 and is fixed to a guide tube 22 having a vertical axis. A guide rod 23 is inserted through the guide cylinder 22, and thus the screw rod 19 can be displaced up and down while having a vertical axis. The elevating means 24 elevates and lowers the mounting member 21. A compression spring 25 is interposed between the base 6 and the mounting member 21. The mounting member 21, and thus the threaded rod 19 via the motor 20, is thus provided with a downward spring force indicated by the arrow 26.

The vacuum suction means 27 can be moved by a three-dimensional moving means 28 including a horizontal moving means such as an XY table and a Z-axis driving means. A fitting recess 30 for vacuum-sucking the nut 8b is formed at the lower end of the suction member 29 of the suction means 27. The fitting recess 30 is a recess having a regular hexagonal cross section perpendicular to the axis shown in FIG. 3, and the passage 31 is connected to the vacuum source 33 via a flexible conduit 32. .

FIG. 4 is a block diagram showing the electrical construction of the embodiment shown in FIGS. The processing circuit 35, which is realized by a microcomputer or the like, includes a motor 20,
The elevator means 24, the moving means 28 of the suction member 29, and the cylinder 12 are connected in relation to and control them.

FIG. 5 is a flow chart for explaining the operation of the processing circuit 35 shown in FIG. Step a1
2 to step a2, the single nut indicated by reference numeral 8a in FIG. 2 is attached to the stopper 15 at the predetermined position 16 along the guide protrusion 11 in the direction of the arrow 14 by the push rod 13 of the cylinder 12. It is moved until it abuts. When the flat surface 41 of the nut 8b is in contact with the stopper 15, the nut 8b is prevented from rotating around its axis. The elevating means 24 lowers the mounting member 21 so that the small-diameter guide protrusion 37 of the screw rod 19 is below the base 6 before the nut 8b is brought to the predetermined position 16.

After the nut 8b is brought to the predetermined position 16, in step a3, the motor 20 is driven to rotate normally so that the screw rod 19 is screwed into the screw hole 17 of the nut 8b. The lifting means 24 raises the mounting member 21, and thus the threaded rod 19. Nut 8b
Since the rotation is blocked by the guide protrusion 11 and the stopper 15 as described above, the guide protrusion 37 of the screw rod 19 fits into the screw hole 17, and the outer screw of the screw rod 19 fits into the screw hole 17 of the nut 8b. Screw together. After that, the elevating means 24 is stopped. In this way, with the screw rod 19 at least partially screwed into the screw hole 17 of the nut 8b, the motor 20 is further rotated in step a4, and the spring 25
While the nut 8b is being pressed downward by the screw rod 19, the screw rod 19 rises, and then the motor 20 is stopped. Next, at step a5, the suction member 2 is moved by the moving means 28.
9 is moved and lowered, and the nut 8b is fitted into the fitting recess 30 of the suction member 29. The fitting recess 30 conforms to the outer shape of the nut 8b, and is formed, for example, in a regular hexagon in this embodiment. The upper end surface of the nut 8b contacts the step 43 of the fitting recess 30, and the lower end surface of the suction member 29 is above the stopper 15 and the guide protrusion 11. In this way, the nut 8b screwed to the screw rod 19 remains in the posture of the nut 8b, and in this state, the nut 8b is fitted into the fitting recess 30 of the suction member 29. The nut 8b can be kept in a correct posture in the fitting recess 30.

Next, at step a6, the motor 20 is rotated in the reverse direction so that the screw rod 19 is disengaged from the screw hole 17 of the nut 8b. At this time, the mounting member 21 is moved by the elevating means 24.
The screw rod 19 is lowered corresponding to the rotation speed thereof. When the screw rod 19 is separated from the nut 8b in this way, the motor 20 is stopped, and the elevating means 24 is operated by the screw rod 19.
The guide protrusions 37 are below the surface of the base 6 and are in an initial state in which they are stopped. Thus, step a7
After the above, the series of operations is ended.

The nut 8b accurately fitted in the fitting recess 30 of the suction member 29 in a desired posture is also provided in a desired position where bolts or the like are to be tightened by the movement means 28. Then, the suction member 2
9 is driven to rotate around its axis, and nut tightening is automatically performed.

The present invention is not only implemented in connection with automatic nut tighteners, but can also be implemented in other applications.

[0017]

As described above, according to the present invention, the nut is moved to a predetermined position by the moving means, then the screw rod is screwed from below the nut, and the screw rod is screwed to the nut. In this way, the nut can be securely sucked in the fitting recess by the suction means while the nut is accurately held in the desired posture. As a result, the nut is not sucked and supplied in an undesired posture, and it is possible to prevent the subsequent nut tightening from becoming insufficient or impossible.

[Brief description of drawings]

FIG. 1 is a simplified sectional view showing a configuration of an embodiment of the present invention.

FIG. 2 is a plan view of the embodiment shown in FIG.

FIG. 3 is a perspective view showing a state in which a nut 8b is in contact with a stopper 15.

FIG. 4 is a block diagram showing an electrical configuration of the embodiment shown in FIGS.

5 is a flowchart for explaining the operation of the processing circuit 35 shown in FIG.

FIG. 6 is a sectional view for explaining the prior art.

[Explanation of symbols]

 6 Base 7 Nut Aligning Means 8, 8a, 8b Nut 12 Double Acting Pneumatic Cylinder 15 Stopper 18 Nut Holding Means 19 Screw Rod 20 Motor 24 Elevating Means 27 Vacuum Adsorbing Means 28 Moving Means 29 Adsorbing Members 30 Fitting Recesses 33 Vacuum Sources

Claims (1)

[Claims] 1. A means for moving a nut to a predetermined position, a means provided below the nut at the predetermined position for holding a nut by rotationally driving a screw rod screwed to the nut, An automatic nut feeder, comprising: a fitting recess into which the nut held by the holding means is fitted, and means for adsorbing the nut in the fitting recess.