JPH11188536A - Automatic screw tightening machine - Google Patents

Abstract

(57) [Problem] To provide an automatic screw tightening machine capable of preventing redundant supply of screws. A driver bit (10) reciprocally movable by the operation of a first cylinder (3) and rotatable in response to the drive of a motor (6), reciprocally movable with the driver bit (10) and reciprocated in the axial direction of a driver bit. It has a movable screw guide 11, and the screw guide 11 is configured to be movable in response to the operation of the second cylinder 26. Further, an air suction device 16 and an air injection device 17 are connected to the screw guide 11 via a direction control valve 15 so that air suction and injection can be switched from the tip of the screw guide 11 to perform switching. I have.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic screwdriver for fastening a screw to a work, and more particularly to an automatic screwdriver suitable for fastening a screw from below a work.

[0002]

2. Description of the Related Art Conventionally, when fastening a screw to a work,
Various automatic screw tightening machines are used.Among these, an automatic screw tightening machine that provides a sleeve that sucks air and suctions and holds the screw on this sleeve is used when fastening screws from the bottom of the work. However, since the screw can be surely held by suction, it is very widely used. In general, a kind of automatic screw tightening machine having the sleeve has a driver table which can reciprocate by the operation of a cylinder, and the driver table can rotate by receiving a motor as a rotary drive source and a drive of the motor. A driver tool provided with a driver bit is installed, and the sleeve is urged toward the distal end so as to always include the driver bit. A chuck unit is arranged on the moving path of the driver bit so that a screw can be held in advance there.The screw held by the chuck unit is sucked and held by a sleeve, then extruded, and pushed to the work. It is configured to be fastened.

[0003]

However, in the above-mentioned conventional automatic screw tightening machine, when the tip of the sleeve is used upward, that is, the automatic screw tightening machine is designed so that the screw can be fastened from the lower side of the work. When the screw guide is released, even if the air suction from the screw guide is released, the screw remains in the screw guide as it is.For example, when the screw is not fastened due to the absence of the work, the screw guide returns There are problems such as the screws returning to the chuck unit and overlapping with the screws supplied for the next fastening operation.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an automatic screw tightening machine capable of preventing redundant supply of screws. In order to achieve this object, the present invention provides a driver bit that is reciprocally movable by actuation of a first reciprocating drive source and rotatable by being driven by a rotary drive source, and a driver bit that is movable integrally with the driver bit. And a screw guide disposed so as to be able to reciprocate in the axial direction. The screw guide is configured to be movable in response to an operation of a second reciprocating drive source.

According to another aspect of the present invention, there is provided a driver bit which is reciprocally movable by actuation of a first reciprocating drive source and rotatable by being driven by a rotary drive source.
A screw guide that is movable integrally with the driver bit and that is reciprocally movable in the axial direction of the driver bit, wherein the screw guide is configured to be movable in response to an operation of a second reciprocating drive source. On the other hand, an air suction device for sucking air and an air ejection device for ejecting air are provided, and switching means for switching these as necessary and connecting to the screw guide is provided. is there.

It is desirable that the switching means be operated in conjunction with the operation of the second reciprocating drive source. In addition, a chuck pawl capable of temporarily holding a screw on a moving path of a screw guide is rotated. Provided possible, if this is always urged to close, by the above-mentioned configuration, the driver bits are returned from the screw guide in a state where they protrude, and they are engaged with the tip of the driver bit by closing the chuck claws. You can flip off the screw that you have.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes an automatic screwing machine. A first cylinder 3, which is an example of a first reciprocating drive source, is disposed on a base 2.
Driver table 4 which is connected to the rod 3a and can reciprocate.
have. The driver base 4 is guided by a slide unit 5 fixed to the base 2. A motor 6, which is an example of a rotary drive source, is installed on the upper surface of the driver base 4, and a gear unit is mounted on an output shaft of the motor 6. A universal joint 8 connected via a guide 7 is rotatably guided. A driver bit 10 is connected to a distal end of the universal joint 8 via a connecting shaft 9, and is configured to rotate integrally with the motor 6 when driven by the motor 6.

Reference numeral 11 denotes a substantially cylindrical screw guide which is urged so as to enclose the connecting shaft 9 and the driver bit 10, and is upwardly moved by a spring 12 so as to enclose the connecting shaft 9 and the driver bit 10. It is provided with bias. The screw guide 11 has a first sleeve 13 integrally formed with an engaging portion 13a at an upper portion, and a second sleeve 14 connected to the first sleeve 13. An air suction device 16 for suctioning air and an air ejection device 17 for ejecting air are connected to 13a via a direction control valve 15, which is an example of switching means. Note that an ejector pump, a vacuum pump, or the like is used for the air suction device 16, and a general factory air facility that accumulates air compressed by a compressor in a tank is used for the air injection device 17.

On the other hand, a chuck table 18 is fixed below the base 2. The chuck table 18 has a chuck unit 19 configured to hold a screw on a moving path of the driver bit 10, An operation mechanism 25 for operating the screw guide 11 is arranged.

The chuck unit 19 includes a chuck body 20 that can guide the screw guide 11 and a pair of chuck claws 21 and 21 that are urged to always close the chuck body 20 and rotatably connected thereto. A holding hole 21a capable of holding a screw is formed separately on the opposing surfaces of the chuck claws 21 and 21. The operation mechanism 25 has a second cylinder 26 as an example of a second reciprocating drive source, and an operation plate 27 that can reciprocate as the rod of the second cylinder 26 expands and contracts. At the tip of the operation plate 27, a notch 27a surrounding the screw guide 11 is formed. This notch 27
a is a width that can be engaged with the engaging portion 13a of the screw guide 11, and thus the screw guide 11 can be moved alone in the axial direction of the driver bit 10 by raising the operation plate 27. It is possible.

In the automatic screw tightening machine 1, a supply hose (not shown) extending from a screw supply device (not shown) is connected to the chuck unit 19, and the screw is fed by air through the hose. The supplied screw fits into the holding hole 21a of the chuck claws 21 and 21, and is held there by continuously blowing the air that has fed the screw under pressure. Then, when the cylinder 3 is operated and the driver base 4 is raised, the driver bit 10 and the screw guide 11 are raised together and approach the screws held by the chuck claws 21 and 21. At this time,
The direction control valve 15 is at a position where the air suction device 16 is connected to the screw guide 11, whereby air is sucked from the tip of the screw guide 11. Therefore, the screw is sucked into the screw guide 11 as the screw guide 11 approaches.

Thereafter, as shown in FIG. 2A, when the screw guide 11 pushes the chuck pawls 21 and 21 to abut against the work, the driver bit 10 moves up the screw guide 11 in response thereto. Thus, the screw sucked and held is pushed out, and is fastened to the work as the driver bit 10 rotates by receiving the drive of the motor 6.

After the screws are tightened as described above, in the automatic screw tightening machine 1, as shown in FIG. 2B, first, the second cylinder 26 operates to lower the operation plate 27, and the screw guide 11 The notch 27a is engaged with the engaging portion 13a, and the notch 27a is retracted. Thereby, the screw guide 11
Can be removed from the work and the tip of the driver bit 10 can be protruded, and even if the screw remains unfastened due to the absence of the work (the screw in such a case is hereinafter referred to as an unfastened screw). This can be reliably eliminated. Further, in response to the operation of the second cylinder 26, the direction control valve 15 is switched and the screw guide 11 is connected to the air injection device 17. For this reason,
Air can be ejected from the tip of the screw guide 11, and the unfastened screw remaining at the tip of the driver bit 10 can be more reliably removed.

The first cylinder 3 is the same as the second cylinder 2
After a predetermined period of time from the operation of 6, the driver starts returning, and lowers the driver base 4 to return the driver bit 10 to the original position.
As a result, the driver bit 10 is
When the unfastened screw is not removed by the retreating of the screw guide 11 and the ejection of air, the screw can be returned to the chuck pawl as shown in FIG. It can be locked to the tips of the chuck 21 and 21 and can be removed by flipping off with the closing operation of the chuck claws 21 and 21. In order to retract the driver bit 10 while protruding from the screw guide 11, the cylinders 3
It is necessary to provide a variable throttle valve (not shown) in the air pressure control circuit (not shown) of 26 and adjust the operating speed to the same.

The structure of the automatic screw tightening machine of the present invention is as follows.
The present invention is not limited to only the above-described embodiments, and can be replaced with elements that produce the same functions and effects without departing from the gist of the invention.

[0016]

As described above, according to the automatic screw tightening machine of the present invention, the screw guide is configured to retreat independently by the operation of the cylinder, so that the driver bit is projected from the screw guide. There is an advantage that the screw which is not fastened and which is not fastened can be eliminated, and the screw can be prevented from being supplied repeatedly during the next screw tightening operation.
In addition, since a directional control valve that switches by receiving the operation of the cylinder is provided, it is possible to switch so that the air injection device is connected to the screw guide, and from the tip of the screw guide as the driver bit projects. There are advantages such as the ability to inject air and more reliably remove unfastened screws.

[Brief description of the drawings]

FIG. 1 is a front view of an automatic screwing machine according to the present invention.

FIG. 2 is an enlarged sectional view of a main part showing an operation state of the automatic screw tightening machine according to the present invention.

FIG. 3 is an enlarged sectional view of a main part showing an operation state of the automatic screw tightening machine according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automatic screwing machine 3 1st cylinder 6 Motor 10 Driver bit 15 Direction control valve 16 Air suction device 17 Air injection device 19 Chuck unit 21 Chuck claw 21a Holding hole 26 Second cylinder 27 Operation plate

Claims (4)

[Claims] 1. A driver bit that is reciprocally movable by the operation of a first reciprocating drive source and is rotatable by being driven by a rotary drive source, and reciprocates in an axial direction of the driver bit that is movable integrally with the driver bit. An automatic screw tightening machine, comprising: a screw guide freely disposed; and wherein the screw guide is configured to be movable in response to an operation of a second reciprocating drive source. 2. A driver bit which is reciprocally movable by operation of a first reciprocating drive source and rotatable by being driven by a rotary drive source, and reciprocates in an axial direction of the driver bit which is movable integrally with the driver bit. An air suction device for sucking air, and an air ejecting device for ejecting air, the screw guide having a freely arranged screw guide, wherein the screw guide is configured to be movable in response to an operation of a second reciprocating drive source. And a switching means for switching these as needed and connecting to the screw guide. 3. The automatic screwdriver according to claim 2, wherein the switching means operates in conjunction with the operation of the second reciprocating drive source. 4. The apparatus according to claim 1, wherein a chuck pawl capable of temporarily holding the screw is rotatably provided on the moving path of the screw guide, and is biased so as to be always closed. 3. The automatic screwing machine according to 3.