JPH09174350A - Automatic screw fastener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic screw fastener to prevent falling-off of a screw fastening tool such as a box bit. SOLUTION: This automatic screw fastener is provided with a box bit 4 to rotate by driving of a rotational driving source installed in a gripping part, and a sleeve material 5 movable in the axial direction to this box bit 5 is slidably arranged along the gripping part, and a chuck unit 6 to hold a screw is integrally installed in this sleeve material 5, and the box bit 4 is constituted so as to project from the chuck unit 6 when the sleeve material 5 slidingly moves. The box bit 4 is prevented from slipping out by being screw-fitted to a driving shaft 3b of the rotational driving source. The box bit 4 is constituted so as to be maintained in a condition of projecting from the chuck unit 6 by a locking means 10, and therefore, workability at box bit replacing time is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic screw tightener for tightening a screw on a work, and more particularly to an automatic screw tightener for preventing a screw tightening tool such as a driver bit or a box bit from falling off.

[0002]

2. Description of the Related Art Conventionally, in an automatic screw tightening machine provided with a screw tightening tool such as a driver bit and a box bit which are rotated by driving a rotary drive source such as a motor, the screw tightening tool is selected according to the size of the screw to be tightened. In many cases, a connecting means for attaching / detaching the member on the rotary drive source side and the screw tightening tool is used so that they can be exchanged for use. A typical example of this connecting means is holding a steel ball. This is configured by providing a fitting hole into which a screw tightening tool can be fitted in a member on the rotary drive source side, and providing a steel ball that constantly protrudes by the bias of a spring in this fitting hole while Is formed by forming a groove into which this steel ball fits when it is fitted in the fitting hole.By simply inserting and removing the screw tightening tool into and from the fitting hole, the screw tightening tool can be installed and removed. It is configured so that it can be performed. This kind of connecting means is widely used in a screw tightener in which a screw tightening tool is always housed inside, such as a hand type automatic screw tightener having a chuck unit for holding a screw. The replacement of the tightening tool is performed by retracting the chuck unit to expose the screw tightening tool, pulling it out, and connecting the desired screw tightening tool.

[0003]

In the automatic screw tightening machine which employs the above-mentioned means for connecting the screw tightening tool, since the screw tightening tool can be easily attached and detached, the workability when exchanging the screw tightening tool is extremely simple. However, since it is easy to attach and detach, it is easy to operate the automatic screw tightener while the screw tightening tool is engaged with the engaging part of the screw head during screw tightening work. There is a problem such as that it will come off at the connecting part and fall off.

[0004]

SUMMARY OF THE INVENTION An automatic screw tightener of the present invention is provided with a screw tightening tool such as a driver bit or a box bit which is rotated by the drive of a rotary drive source such as a motor, and an axis line is provided to the screw tightening tool. Provide a sleeve material that can move independently in one direction, and arrange a chuck unit that holds a screw on this sleeve material.When the sleeve moves to the screw tightening tool side, the screw held by the chuck unit is moved by the screw tightening tool. It is configured to be extruded. Moreover, the screw tightening tool is screwed and connected to the drive shaft of the rotary drive source to prevent the screw tightening tool from coming off, and the first engaging hole provided in the drive shaft and the chuck unit or the sleeve material. Is provided with a second engaging hole and a locking pin that is inserted in a state where these engaging holes are aligned with each other. Improves workability when exchanging tools.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, reference numeral 1 denotes a hand-type automatic screw fastening machine, which has a cylindrical grip portion 2 on which a start switch (not shown) is arranged. The grip 2 includes a motor 3a and a motor 3a.
Is attached to the output shaft of the drive shaft 3b. The drive shaft 3b of the rotary drive source 3 is inserted through the inside of the grip portion 2 and extends forward, and the tip thereof has a drive portion 4a engageable with the head of the bolt.
A box bit 4 which is an example of a screw tightening tool having a screw is screwed. The box bit 4 is provided with a flat surface portion 4b facing the circumference, and is configured so that a screwdriver such as a spanner can be engaged therewith. Further, a cylindrical sleeve material 5 slidable along the inner surface of the grip portion 2 is fitted by being constantly urged downward by a spring 5a to slide along the grip portion 2. By doing so, the box bit 4 can be moved independently. Further, a chuck unit 6 holding a screw pneumatically fed from an external supply device (not shown) is attached to the tip of the sleeve member 5 so as to operate integrally.

The chuck unit 6 is made of a sleeve material 5.
A chuck main body 7 fixed to the chuck main body 7, a pair of chuck claws 8 that are always closed and provided on the chuck main body 7, and a substantially cylindrical hose fitting 9 to which a screw supply feed pipe extending from a supply device is connected. The chuck body 7 has a guide hole 7a for guiding the box bit 4.
Is formed, and the box bit 4 is always positioned in the guide hole 7a. In addition, a holding hole 8a through which the hose fitting 9 is always communicated is separately formed on the surface of the chuck unit 6 that faces the chuck claws 8 so that a screw for feeding the hose fitting 9 can be held. Further, the hose fitting 9 is rotatably attached to the chuck body 7, and is configured to retreat from the moving path of the box bit 4 when the box bit 4 moves forward.

Further, the automatic screw tightener 1 has a drive shaft 3b.
Locking means 1 for keeping the box bit 4 protruding from the chuck claw 8 when replacing the box bit 4 screwed to the
It has 0. The locking means 10 is provided on the drive shaft 3b.
A first engaging hole 11 formed by penetrating at a diametrical position, a second engaging hole 12 communicating with the guide hole 7a of the chuck body 7, and the first engaging hole 11 and the second engaging hole. It is composed of a locking pin 13 which can be fitted in the hole 12. In addition,
The locking pin 13 is always outside the machine and is used only when necessary.

When tightening the screw with the automatic screw tightener 1 having the above-mentioned structure, the screw is supplied to the chuck unit 6 through the feeding hose and fitted and held in the holding hole 8a of the chuck claw 8. In this state, when the automatic screw tightening machine 1 is moved to the work clamping position and the chuck unit 6 is pressed against the work, the sleeve member 5 slides against the spring 5a, and the box bit 4 is substantially advanced. afterwards,
The box bit 4 comes into contact with the screw held by the chuck claw 8. When the start switch is pressed in this state, the rotary drive source 3 drives the box bit 4 to rotate, and the screw is fastened to the tightening position of the work. At that time, the driving portion 4a of the box bit 4 may be caught in the engaging portion of the screw due to the tightening torque. However, in the automatic screw tightening machine 1, the box bit 4 is driven by the drive shaft of the rotary drive source 3. Since it is screwed to and connected to 3b, the box bit 4 will not fall off even if the automatic screw fastening machine 1 is moved as it is.

In such screw tightening work, when the screw to be used is changed and the box bit 4 up to that time cannot cope, the box bit 4 is replaced. In the automatic screw tightener 1, when the box bit 4 is replaced, the sleeve member 5 is slid against the spring 5a so that the first engagement hole 11 and the second engagement hole 12 communicate with each other. At this time, the box bit 4 expands the chuck claw 8 and projects forward. In this state, when the locking pin 13 is inserted into the first and second engaging holes 11 and 12, the sleeve Restoration of material 5 is restricted and box bit 4
Can be kept protruding from the chuck claw 8.
Then, using a screwdriver such as a spanner, box bit 4
Is rotated and removed from the drive shaft 3b, and a new box bit 4 is screwed onto the tip of the drive shaft 3b. At this time, the locking means not only keeps the box bit protruding from the chuck unit, but also prevents the drive shaft from rotating and prevents the box bit from rotating together when the box bit is removed. After completing the replacement of the box bit 4 in this way, if the locking pin 13 is pulled out and the sleeve member 5 is returned,
It is possible to perform screw tightening work corresponding to the changed screw.

[0010]

As described above, the automatic screw tightening machine of the present invention is provided with a screw tightening tool such as a driver bit or a box bit which is rotated by the drive of the rotary drive source, and the screw tightening tool has an axial direction. The sleeve material that can be moved independently is placed on this sleeve material, the chuck unit that holds the screw on the axis of the screw tightening tool is placed on this sleeve material, and the sleeve material is held by the chuck unit by moving to the screw tightening tool side. The screw is pushed out by the screw tightening tool, the screw tightening tool is screwed to and connected to the drive shaft of the rotary drive source, and the first engaging hole provided in the drive shaft and the chuck unit or the sleeve. A locking means composed of a second engaging hole formed in the material and a locking pin inserted in a state where these engaging holes are aligned with each other is provided, and the screw tightening tool is equipped with a chucking tool. And it is configured to be maintained in a state of protruding from the click unit. Therefore, even if the automatic screw tightening machine is moved with the screw tightening tool sticking to the screw, there is an advantage that the screw tightening tool will not come off at the connecting portion and fall off. Since the fastening means can keep the screw tightening tool protruding from the chuck unit, there is an advantage that the screw tightening tool can be replaced very easily.

[Brief description of the drawings]

FIG. 1 is an enlarged partial cutaway sectional view of an essential part of an automatic screw tightener according to the present invention.

FIG. 2 is a front view showing a vertical cross section of the automatic screw tightener according to the present invention.

[Explanation of symbols]

 1 Automatic Screw Tightening Machine 2 Gripping Part 3 Rotational Drive Source 3a Motor 3b Driving Shaft 4 Box Bit 4a Driving Part 4b Flat Surface 5 Sleeve Material 5a Spring 6 Chuck Unit 7 Chuck Body 7a Guide Hole 8 Chuck Claw 8a Holding Hole 9 Hose Metal Fitting 10 Locking means 11 First engaging hole 12 Second engaging hole 13 Locking pin

Claims (2)

[Claims] 1. A screw tightening tool that is rotated by the drive of a rotary drive source attached to a grip is provided, and a sleeve material that is independently movable in the axial direction relative to this screw tightening tool is slidable along the grip. The chuck unit that holds the screw on the axis of the screw tightening tool on this sleeve material,
While the sleeve material slides along the gripping portion, the screw tightening tool can be configured to project from the chuck unit, while the screw tightening tool is screwed and connected to the drive shaft of the rotary drive source, and the screw tightening tool is also provided. The automatic screw tightening machine is characterized in that it is provided with a locking means capable of maintaining a state in which it projects from the chuck unit. 2. The locking means is inserted with the first engaging hole provided in the drive shaft and the second engaging hole provided in the chuck unit or the sleeve member in a state where these engaging holes are aligned with each other. The automatic screw tightening machine according to claim 1, comprising a locking pin.