JPS6221415Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chuck unit for an automatic screw tightening machine having an automatic screw feeding device.

Generally, the chuck unit 1 of this type of automatic screw tightening machine includes a chuck body 3 and a pair of chuck pawls 4 pivotably mounted opposite to each other on the chuck body 3, as shown in FIGS. 4 and 5. chuck claw 4
It consists of a hose fitting 6 that supplies a screw 8 to the top. The tip of the chuck pawl 4 of the chuck unit 1 is always urged by a spring 5 in the direction of closing, and is configured such that a tapered locking hole 18 is formed on the travel path of the driver bit 2. ing. Further, the chuck pawl 4 is configured so that a straight hole 19 is formed in communication with the locking hole 18. This straight hole 1
9 is formed to have a diameter that allows the shaft portion of the screw 8 to be inserted therethrough. In this chuck unit 1, the screw 8 that is engaged with the chuck pawl 4 is long, and the head of the screw 8 is inserted into the straight hole as shown in FIG.
The position of the tip of screw 8 when it reaches 9 is the counterpart 15
When tightening a mating object 15 that does not reach the pilot hole 17, the screw 8 is pushed out from the chuck pawl 4,
When the head of the screw 8 reaches the straight hole 19 after detaching from the locking hole 18, the tip of the chuck pawl 4 is attached to the screw 8.
It is located far away from the periphery of the shaft of the screw 8, and only one end of the outer periphery of the head of the screw 8 comes into contact with the chuck pawl 4, and the tip of the shaft is not guided at all. Therefore, the tip of the shaft portion of the screw 8 tends to wobble, and it often becomes impossible to insert the screw into the predetermined prepared hole 17, resulting in disadvantages such as the inability to perform the desired screw tightening operation.

The present invention has been devised for the purpose of eliminating the above-mentioned drawbacks, and embodiments thereof will be described below with reference to the drawings.
In Figs. 1 and 2, numeral 1 is a chuck unit of an automatic screw tightening machine, and a motor (not shown) is used.
The chuck body 3 has a chuck body 3 in which a driver bit 2, which is rotatable in response to the rotation of the chuck, is inserted therein. This chuck body 3 is the driver bit 2.
The driver bit 2 is configured to be movable integrally with the driver bit 2 and independently. A pair of chuck pawls 4 are disposed on the chuck body 3 so as to be openable and closable, and are biased by a spring 5 so as to close their tips.

A counterpart 15 is disposed below the chuck main body 3, and has a jaw in which a hole is drilled, and a pilot hole positioned below the jaw at a predetermined distance. 4 is configured to stop immediately before it comes into contact with the object 15. A hose fitting 6 is fixed to the chuck main body 3, and a screw guide hole 7 communicating with the hose fitting 6 is bored. A component supply device (not shown) is connected to the hose fitting 6 via a supply pipe (not shown), so that the screw 8 fed by air is supplied to the chuck pawl 4. It is composed of The screw 8 is configured such that its tip has a length sufficient to pass through the jaw of the counterpart 15 and be screwed into a prepared hole located below the jaw at a predetermined distance.

When the chuck pawl 4 is in the closed state, a tapered first locking hole 9 is formed.
A first straight hole 10 is formed which communicates with the locking hole 9 and has a diameter through which the shaft portion of the screw 8 can be inserted. The first straight hole 10 has a diameter larger than the driver bit 2, and is configured so that the driver bit 2 does not come into contact with the chuck pawl 4 when it passes through. Furthermore, the chuck pawl 4 has the first straight hole 1.
A second straight hole 12 is formed so as to communicate with the guide hole 11 and have a diameter slightly larger than the head diameter of the screw 8. It is configured to Further, the chuck pawl 4 has a second straight hole that communicates with the second straight hole 12 and holds the screw 8.
A locking hole 13 is formed.
Further, the chuck pawl 4 has the second locking hole 13.
A third straight hole 14 is formed in communication with the third straight hole 14 and having a diameter that allows the shaft portion of the screw 8 to be inserted therethrough. Moreover, the gap between the first locking hole 9 and the second locking hole 13 is such that when the chuck main body 3 descends and stops at a predetermined position, the tip of the screw 8 held in the first locking hole 9 is It is configured to be equal to the distance to the prepared hole of the counterpart 15.

As shown in FIG. 3, when the automatic screw tightening machine screws the screw 8 which also serves as a spacer into the object 15, the tip of the chuck claw 4 approaches the object 15 and stops at a predetermined position. . Thereafter, the driver bit 2 descends, and its tip abuts the head of the screw 8 held in the first locking hole 9 of the chuck pawl 4. When the driver bit 2 further descends, the screw 8 descends while pushing the chuck pawls 4 apart. At this time, the tip of the shaft of the screw 8 passes through the pilot hole 16 on the upper side of the counterpart 15. The screw 8 further descends, its head passes through the first locking hole 9, and the screw 8 is inserted into the first straight hole 1.
0 and the guide hole 11 to reach the second straight hole 12. At this time, since the head of the screw 8 is smaller than the diameter of the second straight hole 12, the tip of the chuck pawl 4 becomes closed again, and the shaft portion of the screw 8 is guided by the chuck pawl 4. In this state,
When the screw 8 descends inside the chuck pawl 4, the head of the screw 8 comes into contact with the second locking hole 13, and the chuck pawl 4 is pushed open again. The head of screw 8 is in the third straight hole 1
4, the tip of the screw 8 smoothly attaches to the other object 15.
reaches the pilot hole 17. Then driver bit 2
The rotation of is transmitted to the screw 8, and the screw 8
screwed into. As explained above, the present invention is configured so that the chuck pawl is stopped at a position away from the pilot hole of the object, and the chuck pawl is provided with two upper and lower locking holes, and the screw with the long shaft portion is temporarily inserted into the chuck pawl. After holding it in the upper locking hole, it is pushed out into the lower locking hole by advancing the driver bit to center the screw shaft and also to align the upper locking hole with the lower locking hole. Since the gap is configured to be equal to the distance from the tip of the screw shaft located in the lower locking hole to the pilot hole of the mating object, the tip of the screw shaft will not pass through the blank hole in the jaw. The shaft of the screw is centered by a chuck pawl until it touches the pilot hole, allowing the screw shaft to reach the pilot hole without wobbling on the way down, allowing for reliable and quick tightening. Not only does this work become possible, but the tip of the screw shaft fits securely into the pilot hole, preventing it from dancing around the pilot hole of the target object, and there is no damage to the surface of the target object. There is.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of the present invention, Fig. 2 is a sectional view taken along the line A-A in Fig. 1, Fig. 3 is a sectional view of the main parts showing the operating state of the invention, Figs. 4 and 5. 6 is a sectional view of the main part showing the conventional example, and FIG. 6 is a sectional view of the main part showing the operating state of the conventional example. 1... Chuck unit, 2... Driver bit, 3... Chuck body, 4... Chuck claw, 5
... Spring, 6 ... Hose fitting, 7 ... Screw guide hole, 8 ... Screw, 9 ... First locking hole, 10 ... First straight hole, 11 ... Guide hole, 12 ... Second Straight hole, 13...Second locking hole, 14...
3rd straight hole, 15... mating object, 16... pilot hole, 17... pilot hole, 18... locking hole, 19... straight hole.

Claims (1)

[Scope of Claim for Utility Model Registration] A rotatable driver bit 2 and a chuck body 3 housing the rotatable driver bit so as to be inserted therein are integrated, and the driver bit 2 is configured to move independently. A pair of chuck pawls 4 are installed on the moving path of the chuck 2 so as to be openable and closable, and the tips of the chuck pawls 4 are always biased in the closing direction, and the chuck pawls 4 are stopped at a position immediately before they come into contact with the object 15. On the other hand, a first locking hole 9 and a second locking hole 13 are formed in the chuck pawl 4 in two stages, upper and lower, and after the screw 8 is temporarily held in the first locking hole 9, a screwdriver is inserted. By independently moving the bit 2, the screw 8 is pushed out from the first locking hole 9, held in the second locking hole 13, the shaft of the screw 8 is centered, and it is screwed into the pilot hole of the counterpart 15. In the chuck unit of an automatic screw tightening machine configured to be inserted into the chuck unit, the upper first locking hole 9 provided in the chuck pawl 4
A first straight hole 10 is provided between the first straight hole 10 and the second locking hole 13, and the first straight hole 10 is formed to have a diameter larger than that of the driver bit 2.
The gap between the first locking hole 9 and the second locking hole 13 is stopped at a predetermined position from the tip of the shank of the screw 8 held in the second locking hole 13 of the chuck claw 4 to the pilot hole of the counterpart 15. A chuck unit for an automatic screw tightening machine characterized by a distance of up to .