JPH09234636A - Automatic screw tightening machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic screw tightening machine capable of holding a screw sucked by a suction sleeve upright in the automatic screw tightening machine provided with the suction sleeve to suck and hold the screw by air suction. SOLUTION: An automatic screw tightening machine is provided with a driver bit 1 to be rotated by a rotation power source, a guide sleeve 6 in which the driver bit 1 is constantly housed, and an air suction mechanism to be connected to the guide sleeve 6. A suction sleeve 7 is slidably stored in the guide sleeve 6 so as to suck a head part of the screw to be guided to the guide sleeve 6 and hold it. The suction sleeve 7 is arranged so as to be brought into contact with the head part of the screw for suction and holding when the head part of the screw is sucked by the guide sleeve 6, and the screw can be held upright by sucking and holding the screw in an early stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic screw tightening machine that sucks and holds a screw on a suction sleeve, supplies the screw to a predetermined position, and tightens the screw by a driver bit.

[0002]

2. Description of the Related Art Conventionally, in the case of tightening a screw on a work, a driver bit that is rotated by the drive of a rotary drive source, a suction sleeve that always contains this driver bit, and an air suction mechanism connected to the suction sleeve. An automatic screw tightening machine composed of and is generally widely used. As shown in FIG. 8, the inner diameter portion of the suction sleeve 50 in this type of automatic screw fastening machine is a guide portion 51 that can guide the head of the screw, and is slightly in communication with the guide portion 51 than the guide portion 51. A two-step structure is formed by the engaging portion 52 formed to have a small diameter, and the head of the screw is guided and taken in by the tip end portion 51 by air suction, and this is brought into contact with the engaging portion 52 and suction-held. Is configured.

[0003]

However, in the above-described conventional automatic screw tightening machine, particularly when an attempt is made to hold a screw having a shaft portion shorter than the head diameter by suction, the screw is easily inclined in the suction sleeve. There is a frequent problem that occurs. Also, in the case of a screw in which the tip of the shaft portion protrudes from the tip of the suction sleeve, although it can be held relatively stable and upright, if the screw is supplied to a position deviating from the fastening position of the workpiece, the suction sleeve Since the thrust force of (1) acts on the work intensively from the screw shaft, there is a problem that the work is locally damaged.

[0004]

SUMMARY OF THE INVENTION An automatic screw tightener according to the present invention is connected to a driver bit which is driven by a rotary drive source to rotate, a guide sleeve which always contains the driver bit, and a guide sleeve. And an air suction mechanism. A suction sleeve is slidably accommodated in the guide sleeve, and is configured to be attracted to and held by the head of the screw guided by the guide sleeve. The suction sleeve is arranged so that when the head of the screw is sucked by the guide sleeve, the suction sleeve is brought into contact with the head of the screw to hold it by suction. It is configured so that it can be held. The suction sleeve can be constantly urged toward the tip end side of the guide sleeve by a spring.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 is a driver bit of an automatic screwdriver used as a tip unit of a robot or a work unit attached to a predetermined work station of a conveyor line, and a rotary drive source (not shown) such as a motor. It is configured to be able to rotate by receiving the driving force of (1) and to be moved up and down by driving of an elevation drive source (not shown). Further, below the driver bit 1, there is provided a screw holding portion 2 which is located on the moving path and holds the screw in an upright state. The screw holding portion 2 has a screw supply device (not shown). ) To the screw 3 in which the collar 31a is integrally formed on the head 31 as shown in FIG.
0 (hereinafter, referred to as a flanged screw 30) is configured to be supplied one by one. Further, the driver bit 1
A suction holding portion 3 for sucking and holding the flanged screw 30 held by the screw holding portion 2 is provided at a position where the suction holding portion 3 is included, and the suction holding portion 3 performs an air suction mechanism (FIG. (Not shown) is connected so that air can be sucked from the tip.

The suction holding portion 3 is capable of moving up and down integrally with the driver bit 1 and having a predetermined amount with respect to the driver bit 1.
The air suction mechanism is provided with a connecting member 5 integrally connected to the sleeve member 4 which can be independently moved up and down, and a guide sleeve 6 integrally connected to the connecting member 5. It is provided to perform air suction. The guide sleeve 6 in the suction holding portion 3 has a tubular shape capable of guiding the flange portion 31a of the flanged screw 30 inside, and a cylinder into which the head 31 of the flanged screw 30 can be fitted. Shaped suction sleeve 7 is slidably accommodated. The suction sleeve 7 is constantly urged by the spring 8 toward the tip end side of the guide sleeve 6, and is kept so as not to fall off when the flange portion 7a integrally formed on the upper portion comes into contact with the guide sleeve 6. Moreover, the suction sleeve 7 is arranged such that its tip end surface is slightly retracted inward from the tip end surface of the guide sleeve 6, and the head 31 of the flanged screw 30 is sucked into the guide sleeve. At this point, it is configured to come into contact with the flange portion 31a of the flanged screw 30.

In the above automatic screw tightener, as shown in FIG. 3 (a), the driver bit 1 is provided above the workpiece fastening position.
When the screw 30 is supplied from the screw supply device (not shown) to the screw holding part 2 in the state where the driver bit 1 and the suction holding part 3 are operated by the operation of the elevation drive source (not shown). It descends together and approaches the flanged screw 30 held by the screw holding portion 2. At this time, since air is sucked from the tip of the suction holder 3 by the operation of the air suction mechanism (not shown), as shown in FIG. 3B, the collar held by the screw holder 3 is attached. The screw 30 is sucked into the guide sleeve 6 of the suction holding portion 3, and is sucked and held by the flange portion 31 a contacting the tip end surface of the suction sleeve 7.

A flanged screw 3 sucked by the suction sleeve 7.
In 0, the head 31 is only accommodated in the guide sleeve 6, and the shaft 32 projects from the tip of the guide sleeve 6. If the collar screw 30 is sucked and held early when the head 31 is housed in the guide sleeve 6 as described above, the amount of movement of the collar screw 30 when sucked up by air is reduced, and the collar screw 30 is securely held. It is possible to hold it upright. In addition, since the suction sleeve 7 can be retracted into the guide sleeve 6 against the bias of the spring 8, as shown in FIG. Even if it is supplied to a position that is out of the fastening position, the flanged screw 3
Thrust from the suction holding unit 3 does not act on 0. Therefore, it is possible to prevent damage to both the work and the suction holding unit 3. In addition, since the threaded portion 32 of the flanged screw 30 always protrudes from the suction holding portion 3, in a hand-type automatic screw tightener that an operator holds and operates by hand,
The flanged screw 30 can be easily aligned with the fastening position of the workpiece.

The suction holding portion 3 and the driver bit 1 continue to descend even after the collar screw 30 is held, and the collar screw 30 is pushed out in front of the screw holding portion 2 to make the collar screw 3
The tip of 0 is matched with the fastening position of the work. At this time, since the operation of the lifting drive source continues, the suction sleeve 7 slides to ground the tip end surface of the guide sleeve 6 to the work surface, and then descends to the position where the driver bit 1 engages with the flanged screw 30. To do. After that, the driver bit 1 is rotated by the drive of the rotary drive source (not shown), and the screw 30 with the collar is rotated.
Engages with the drive hole of and rotates this integrally,
To the work.

Next, another embodiment of the present invention will be described. In the automatic screw tightening machine according to the other embodiment, the suction holding part has only a slightly different structure from the above-described automatic screw tightening machine, and otherwise has the same structure. Only the holding unit will be described. As shown in FIG. 5, the suction holding portion 13 in this automatic screw tightening machine is similar to the suction holding portion 3 described above in that the guide sleeve 16 that guides the head 31 of the flanged screw 30 and the guide sleeve 16 are provided along the guide sleeve 16. And a slidable suction sleeve 17. However, unlike the suction holding unit 3 described above,
The suction sleeve 17 is provided without being biased by a spring or the like, and is configured to be able to freely slide along the guide sleeve 16.

In this suction holding portion 13, as shown in FIG. 6A, when the head portion 31 of the collared screw 30 is sucked by the suction sleeve 17 by air suction, the suction sleeve 17
6 is retracted into the guide sleeve 16 while holding the flanged screw 30 as shown in FIG. 6 (b). As described above, the flanged screw 30 can be held upright by suction-holding the flanged screw 30 on the suction sleeve 17 near the tip of the guide sleeve 16. However, in the suction holding portion 3,
It is possible to take in and hold the collared screw 30 thus held upright in the guide sleeve 16.
The shaft portion 32 of the flanged screw 30 comes into contact with the projecting portion of the workpiece during the screw tightening work, thereby preventing the problem that the flanged screw 30 is inclined at the tip of the suction holding portion 13.

In the description of the embodiment of the present invention, the flanged screw 30 in which the flange portion 31a is integrally formed on the head portion 31 is described as an example, but the suction holding portion in the automatic screw tightener of the present invention is described. Nos. 3 and 13 do not correspond only to screws with a collar, and even screws with a head that does not have a collar can similarly be sucked and held. Thus, the type of screw to be sucked and held can be changed. However, the effect obtained is the same.

[0013]

As described above, in the automatic screw tightener of the present invention, the screw is configured to be suction-held by the suction sleeve slidable along the guide sleeve for guiding the head of the screw. Since the guide sleeve guides the screw head, the screw can be securely sucked and held.

Since the suction sleeve is housed in the guide sleeve so as to suck the head of the screw when the head of the screw is sucked by the guide sleeve, the head of the screw can be held by suction early. As a result, the screw can be sucked and held in the upright state. Moreover, if the suction sleeve is configured so that it can slide freely in the guide sleeve, the screw held by the suction sleeve can be taken into the guide sleeve together with the suction sleeve, and the screw can be attached to the screw holding portion, the work, etc. It is possible to prevent a problem such as contact and falling.

Further, if the screw is sucked and held early as described above, the screw shaft projects from the guide sleeve. However, in this automatic screw tightener, the suction sleeve slides along the guide sleeve. Even if the screw supply position deviates from the predetermined position and the screw touches the surface of the work, the thrust of the guide sleeve can be prevented from acting on the work through the screw. It is possible to prevent damage to each part such as the sleeve and the suction sleeve.

Further, by urging the suction sleeve toward the tip side by the spring, the tip of the screw shaft can be made to always project from the guide sleeve. Especially in the case of a hand-type automatic screw tightener. Has the advantage that the position adjustment during screw tightening can be performed very easily.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of essential parts near a suction holding portion of an automatic screw tightening machine according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a disassembled state of a suction holding portion of the automatic screw fastening machine according to the embodiment of the present invention.

3A and 3B are operation explanatory views in the vicinity of a suction holding portion of the automatic screw tightener according to the embodiment of the present invention.

FIG. 4 is an operation explanatory diagram in the vicinity of a suction holding portion of the automatic screw tightening machine according to the embodiment of the present invention.

FIG. 5 is an enlarged cross-sectional view of a main part in the vicinity of a suction holding portion of an automatic screw fastening machine according to another embodiment of the present invention.

6 (a) and 6 (b) are operation explanatory views in the vicinity of a suction holding portion of an automatic screw tightener according to another embodiment of the present invention.

FIG. 7 is an enlarged front view of the flanged screw.

FIG. 8 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 1 Driver Bit 2 Screw Holding Part 3 Suction Holding Part 4 Sleeve Material 5 Connecting Member 6 Guide Sleeve 7 Suction Sleeve 7a Flange Part 8 Spring 13 Suction Holding Part 16 Guide Sleeve 17 Suction Sleeve 30 Collared Screw 31 Head 31a Collar Part 32 Screw Department

Claims (3)

[Claims] 1. An automatic screw tightening machine comprising a driver bit that is rotated by the drive of a rotary drive source, a guide sleeve that always contains the driver bit, and an air suction mechanism that sucks air through the guide sleeve. An automatic screw tightener, wherein a suction sleeve slidable along the guide sleeve is provided, and a screw sucked into the guide sleeve is suction-held by the suction sleeve. 2. The suction sleeve is provided so as to be housed in the guide sleeve, and is arranged to be attracted to the screw head when the screw head is sucked by the guide sleeve. The automatic screw tightener according to claim 1. 3. The suction sleeve is constantly urged toward the tip end side of the guide sleeve by an elastic body.
Alternatively, the automatic screw tightener according to claim 2.