JP2009190144A - Threaded fastener tightening device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a threaded fastener tightening device which sucks a threaded fastener at the distal end of a driver bit and tightens the fastener. <P>SOLUTION: The driver bit 3 freely insertable into a suction sleeve is integrally equipped with a screw head guide 6 positioned so as to cover the outer circumference of its distal end portion and to slightly protruding the distal end portion, wherein an external cross-sectional shape of the screw head guide 6 is a substantially triangular form to be fitted in the suction sleeve 4. As the external cross-sectional shape of the screw head guide 6 is the substantially triangular form, three air suction passages are formed inside the suction sleeve 4, allowing the device to suck a screw 2 at the distal end of the driver bit 3 while pressing the head portion of the screw 2 with the screw head guide 6. As center run-out of the driver bit 3 is reduced, in addition, the device can reliably tighten the screw 2 even extremely small in head diameter. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a screw component fastening machine that sucks and tightens a screw component to the tip of a driver bit.

  2. Description of the Related Art Conventionally, in a screw component fastening machine that tightens a screw of an example of a screw component by adsorbing a screw to the tip of a driver bit, the screw bit fastening machine includes a driver bit that tightens the screw and a suction sleeve that includes the screw, In many cases, an air suction path is provided between the two and the screw is attached to the tip of the driver bit. In this type of screw part fastening machine, when the screw is sucked, the screw may be tilted and picked up. Therefore, in order to hold the screw in an upright position, the screw head presser is held between the driver bit and the suction sleeve. A sleeve is provided so as to be retractable.

JP-A-9-234636

  In this screw component fastening machine, after the screw supplied to the screw supply position is covered with the suction sleeve, the screw is once adsorbed to the tip of the screw head holding sleeve, and then the screw is erected on the tip as the driver bit is lowered. Can be adsorbed in a posture. However, because of the relationship of providing an air suction path between the driver bit and the screw head presser sleeve, the core runout during rotation of the driver bit is large, and this is especially true when the screw has a very small head diameter. There are disadvantages such as being unable to tighten securely.

  The present invention has been created in view of the above-described problems, and includes a driver bit that is rotated by the rotation of a rotational drive source and an air suction path formed between the driver bit and the driver bit. In a screw part fastening machine equipped with a suction sleeve, a screw head guide that is positioned so as to cover the outer periphery of the tip of the screwdriver bit and project the tip of the screw bit is attached integrally. Is a substantially polygonal shape that fits in the suction sleeve. Further, the screw head guide may be attached to the tip of the driver bit by being elastically biased so as to be retractable.

According to the screw component fastening machine of the present invention, since the outer shape of the cross section of the screw head guide is substantially polygonal, the head of the screw component is formed while forming multiple air suction paths in the suction sleeve. Can be held upright by pushing the screw head guide, and the screw part can be adsorbed to the tip of the driver bit. Further, since the screw head guide integrated with the driver bit is housed in the suction sleeve, the driver bit is less likely to run out of the core and the screw part can be securely tightened. Further, when the screw head guide is attached to the tip of the driver bit so as to be retractable, the strength of the screw head guide contacting the head of the screw part can be adjusted, and the head of the screw part can be adjusted. There is no damage to the department.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. 1 to 3, reference numeral 1 denotes a screw part fastening machine for fastening a screw 2 as an example of a screw part, and a driver bit 3 that rotates by receiving rotation of a rotational drive source (not shown), and the driver bit 3 And a suction sleeve 4 which is elastically biased so as to be retractable with respect to the driver bit 3. The driver bit 3 and the suction sleeve 4 are lowered integrally until immediately before the tip of the suction sleeve 4 comes into contact with the work 5 by the operation of a lifting drive source (not shown), and then the driver bit 3 is lowered alone. The suction sleeve 4 can be inserted.

  The driver bit 3 and the suction sleeve 4 are arranged with a predetermined gap so as to form an air suction path, and an air suction mechanism (not shown) is connected to the upper side of the air suction path. The air in the suction sleeve 4 is configured to be sucked. The driver bit 3 has an enlarged shaft portion 3a connected to a rotational drive source via a connector (not shown) and a tip portion 3b having a shape engageable with the drive hole 2a of the screw 2. is doing. A screw head guide 6 is press-fitted into the driver bit 3 so as to cover the outer periphery of the tip portion 3b and slightly protrude the tip portion 3b, and the driver bit 3 and the screw head guide 6 are integrally fixed. Yes. The external shape of the cross section of the screw head guide 6 is a substantially triangular shape as an example of a substantially polygonal shape, and is formed in a size that fits within the suction sleeve 4. Further, the screw head guide 6 forms three air suction paths with the suction sleeve 4, while contacting the inner wall of the suction sleeve 4 with a small frictional resistance when the driver bit 3 rotates, thereby reducing the core runout. It is configured as follows. Further, the length between the leading edge of the screw head guide 6 and the leading edge of the suction sleeve 4 is long enough for the leg portion of the screw 2 attracted to the tip of the driver bit 3 to protrude from the suction sleeve 4. It is configured so that it can be confirmed that the screw 2 is guided to the pilot hole (or female screw) of the work 5.

  The rotation drive source, the lift drive source, and the air suction mechanism operate when the screw tightening operation is started. When a tightening completion detection device (not shown) attached to the rotation drive source detects the tightening completion, the rotation drive source, It is comprised so that the operation | movement of a raising / lowering drive source and an air suction mechanism may be stopped. The raising / lowering drive source is configured to return at the same time as the tightening is completed, and to return the driver bit 3 and the suction sleeve 4 to rise.

  In the screw component fastening machine, when the screw 2 is supplied to the screw supply position by an air feed or a straight advance feeder (not shown), the screw bit is started and the driver bit 3 is rotated and integrated with the suction sleeve 4. Descend. At the same time, the air suction mechanism is activated and the air in the suction sleeve 4 is sucked. After the suction sleeve 4 reaches the screw supply position and covers the head of the screw 2, the screw head guide 6 contacts the head of the screw 2 and holds the screw 2 in an upright posture. At this time, since the air in the suction sleeve 4 is sucked, the air in the vicinity of the tip of the suction sleeve 4 is formed by three strips of air formed between the suction sleeve 4 and the screw head guide 6 having a substantially triangular cross section. The screw 2 is sucked to the tip of the driver bit 3 by being sucked through the suction path.

  In this state, when the driver bit 3 reaches the screw tightening position where the workpiece 5 is arranged and starts to descend, the leg portion of the screw 2 attracted to the tip of the driver bit 3 contacts the workpiece 5 as shown in FIG. The suction sleeve 4 stops immediately before contact. Thereafter, the driver bit 3 is lowered alone, and the leg portion of the screw 2 reaches the prepared hole (or female screw) of the workpiece 5. At this time, the driver bit 3 rotates in response to the rotation of the rotational drive source. However, since the protrusion of the screw head guide 6 is in contact with the inner wall of the suction sleeve 4 on the tip side, the tip of the driver bit 3 is restrained. Can be rotated. Therefore, there is almost no runout of the driver bit 3, and the screw 2 at the tip of the driver bit 3 is smoothly screwed into the pilot hole (or female screw) of the work 5. This can be securely tightened regardless of the type of screw. Moreover, since the screw head guide 6 is only in contact with the inner wall of the suction sleeve 4 at three points, the frictional resistance is small, and the influence when detecting the tightening torque such as when detecting the completion of tightening can be reduced.

In this embodiment, the screw head guide 6 is fixed integrally with the driver bit 3, but it may be attached to the tip of the driver bit 3 so as to be elastically urged. In this case, the strength of contact with the head of the screw 2 can be adjusted, and the head of the screw is not damaged at all. Further, although the driver bit 3 is moved from the screw supply position to the screw tightening position by the operation of the lifting drive source, this may be performed by a moving means such as a robot.

It is principal part sectional drawing of the screw component fastening machine which concerns on this invention. It is an expanded sectional view along the AA line of FIG. It is explanatory drawing which shows the operating state of the screw component fastening machine which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw component fastening machine 2 Screw 2a Drive hole 3 Driver bit 3a Expansion shaft part 3b Tip part 4 Suction sleeve 5 Work piece 6 Screw head guide

Claims (2)

In a screw component fastening machine including a driver bit that rotates in response to rotation of a rotational drive source, and a suction sleeve that encloses the driver bit so that an air suction path is formed between the driver bit,
The screw head guide, which is positioned so as to cover the outer periphery of the tip of the driver bit and project the tip, is integrally attached to the driver bit, and the outer shape of the cross section of the screw head guide is substantially polygonal to fit in the suction sleeve. A screw part fastening machine that features this.   The screw part fastening machine according to claim 1, wherein the screw head guide is attached to the tip of the driver bit by being elastically biased so as to be retractable.

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