JPH0763883B2 - Fastener - Google Patents

Description

Detailed Description of the Invention 【Technical field】

The present invention relates to a tightening tool called a chuck provided for holding a tool such as a drill bit or a driver bit in an electric drill or an electric screwdriver.

[Background technology]

By providing a taper bush that is rotatable with respect to the shaft to which power is transmitted and rotating the taper bush with respect to the shaft, the tightening claws that are arranged inside the taper bush are radially arranged. In the tightening tool to be moved to, it is necessary to perform the axial coupling between the taper bush and the shaft that guides the claws on its inner surface.
Conventionally, this is done by forming an internal thread on the inner surface of the taper bush, screwing an annular fixing member to the internal thread, and engaging the fixing member with a flange provided at the tip of the shaft. However, this has a problem that it takes time and labor for screwing and assembling takes time. For this reason, it is possible to fix the fixing member to the inner peripheral surface of the taper bush by welding or press fitting.
When tightening the tool, the fixing member may come off the taper bush due to the force of up to 600 kg that acts in the direction of the shaft coming out of the taper bush.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fastener having good assemblability and high strength.

DISCLOSURE OF THE INVENTION

Therefore, the tightening tool according to the present invention includes a shaft to which power is transmitted, a taper bush that is rotatable with respect to the shaft and is coupled in the axial direction, and a radial direction that accompanies rotation of the taper bush with respect to the shaft. In a tightening tool including a claw for tightening that moves, an annular fixing member that axially connects the taper bush and the shaft is provided in the opening of the taper bush that guides the claw on the inner surface. It is characterized in that a retaining ring for retaining the annular fixing member is engaged with a groove formed on the inner peripheral surface of the opening end of the taper bush. The present invention will be described in detail below with reference to the illustrated embodiment. In the illustrated embodiment, the tool 4 can be attached / detached without using a chuck handle by rotating the rotating ring 2 with respect to the handle 3 integrated with the shaft 1. Tool 4 due to careless rotation of the rotary ring 2
In order to prevent the loosening of the rotary ring 2, a lock means for restricting the rotation of the rotary ring 2 is incorporated. The metal cylindrical shaft 1 whose rear end is connected to the drive shaft 10 is
A flange is provided at the tip, and a tapered surface 11 having a diameter that becomes smaller toward the rear is provided on the outer peripheral surface in the axial direction, further, a modified cross-section 12 is provided at the rear end, and a female screw 13 is provided on the inner peripheral surface of the front end. Has been. A cylindrical handle 3 is press-fitted and fixed to the outer periphery of the modified cross-section 12 of the shaft 1,
The float screw 6 is screwed into the female screw 13. The plurality of claws 5 for tightening the tool 4, which is a drill bit or a driver bit, are formed as a forged product in terms of cost and mass productivity, and both have an outer surface as an inclined surface and a rear surface. It has an engaging piece 50 at the end,
The engaging piece 50 is engaged with an engaging groove 60 provided at the tip of the float screw 6. Further, each claw 5 is housed in a slit 70 formed in a conical metal-made guide block 7, and a wing piece is formed on the outer conical surface of the guide block 7.
51 is engaged and is housed inside the taper bush 25 together with the guide block 7. This taper bush
25 is a protrusion 71 protruding from the outer surface of the rear end of the guide block 7.
Is provided at the rear end. The rotating ring 2 is arranged between the taper bush 25 and the handle 3. The rotating ring 2 has a cylindrical main body 20 made of synthetic resin, and has the same cylindrical shape as the main body 20.
It consists of a metal lock fitting 23 fixed in the rear part of the
The lock fitting 23 is adapted to rotate together with the main body 20 by engaging a groove 24 formed on the outer peripheral surface thereof with a protrusion 21 formed on the inner peripheral surface of the main body 20. In addition, the rotating ring 2 rotates integrally with the taper bush 25 by engaging the projection 22 formed on the inner peripheral surface of the main body portion 20 with the groove 26 of the taper bush 25, and also the taper bush 25. On the other hand, the rotation ring 2 can be freely moved in the axial direction. An annular cap 16 as a fixing member is press-fitted between the outer peripheral surface of the shaft 1 having the front end surface in contact with the rear end of the guide block 7 and the inner peripheral surface of the taper bush 25. A washer 17 made of tetrafluoroethylene resin is arranged between the shaft 16 and the flange at the tip of the shaft 1, and a groove 27 formed in the inner peripheral surface of the rear opening end of the taper bush 25 has a C A V-shaped metal retaining ring 18 is engaged. The cap 16 that is prevented from coming off from the taper bush 25 by the snap ring 18 that is an elastic body engages with the flange at the tip of the shaft 1 via the washer 17 to allow the axial direction of the shaft 1 and the taper bush 25. Make a join. The taper bush 25 engages with the rotating ring 2 and the guide block 7 as described above, and the guide block 7 further includes the claws 5.
Which is engaged with the float screw 6 via
The taper bush 25 is rotatable with respect to the shaft 1 together with these members. The float screw 6 and the claw 5 are axially movable with respect to the guide block 7. Next, the locking means is a plurality of engaging grooves formed between the inner peripheral surface of the rotating ring 2 and the outer peripheral surface of the shaft 1, and needle rollers arranged in the respective engaging grooves. It is formed by a one-way clutch as a silent ratchet (free wheel) constituted by 9 and 9. The engagement grooves are formed by the tapered surface 11 of the shaft 1 and the rotary ring 2
Is formed by a concave groove 40 provided on the inner peripheral surface of the lock fitting 23, and has a wedge-shaped cross section in the direction orthogonal to the axial direction of the shaft 1. The means for releasing the lock is such that the engaging groove has an inclination along the tapered surface 11 of the shaft 1 and the rotating ring 2 is slidable in the axial direction with respect to the shaft 1. By this movement, the cross-sectional area of the engagement groove is made variable. The rotating ring 2 is urged axially forward by a spring 30 arranged between the rotating ring 2 and the handle 3. The engaging groove is urged in the direction in which the cross-sectional area of the groove decreases. However, when the tool 4 is attached to the tightening tool, the rear end of the tool 4 may be inserted from the front end opening, and the rotating ring 2 may be rotated while gripping the handle 3. At this time, the locking means holds the rotating ring 2 and the shaft 1 in a separated state, so that the rotation of the rotating ring 2 with respect to the shaft 1 is not hindered, and the taper is increased as the rotating ring 2 rotates. Bush 25, guide block 7 and float screw 6
Rotates with respect to the shaft 1, and the shaft 1
The float screw 6 which is screwed together moves forward to move the claws 5 forward. As a result, the wing piece 51 is attached to the guide block 7
The claws 5 located between the taper bush 25 and the inner peripheral surface of the taper bush 25 gather at the center in the radial direction to tighten the tool 4. Also, during this tightening, a large force F in the direction of retracting the shaft 1 against the taper bush 25 acts as shown in FIG. 2, but since the cap 16 is received by the retaining ring 18, the cap 16 is Detached taper bush
Shaft 1 will not come out of 25. Since the force F reaches a maximum of 700 kg, the snap ring 18 having a hardness of about H _RC 52 is used. When the shaft 1 is rotated for screw tightening work or the like, at this time, the locking means does not act and the rotating ring 2
Relative rotation occurs in the tool, but the rotation of the rotating ring 2 is such that the tool 4 is tightened. When the screw is loosened, the needle roller 9 in contact with the outer peripheral surface of the shaft 1 is moved in a direction to bite into the engagement groove having a wedge-shaped cross section.
The rotary ring 2 is locked against. That is, the relative rotation of the rotary ring 2 with respect to the shaft 1 causes the pawl 5 to move.
Does not spread. Next, in order to remove the tool 4, the rotary ring 2 is rotated with respect to the shaft 1 in the direction opposite to the direction in which the tightening is performed, and the claw 5 is removed.
The rotation of the rotary ring 2 with respect to the shaft 1 is locked by the locking means if the lock ring is unfolded. Do by turning. When the rotary ring 2 is retracted against the spring 30, the cross-sectional area of the engaging groove is increased, and the needle roller 9
Does not come into contact with both the shaft 1 and the rotating ring 2, so that the rotating ring 2 is not locked. When the rotary ring 2 is released, the rotary ring 2 is returned to its original state by being biased by the spring 30.

【The invention's effect】

As described above, in the present invention, the annular fixing member for connecting the shaft and the taper bush in the axial direction is stopped by the retaining ring engaged with the groove formed on the inner surface of the opening end of the taper bush. Therefore, the assembling property is good, and the bonding strength is high and the cost is low.

[Brief description of drawings]

1 is a cutaway front view of an embodiment of the present invention, FIG. 2 is an enlarged vertical sectional view of the same, FIG. 3 is an exploded perspective view of the same, FIG. 4 is a perspective view of the same, and 1 is a shaft. 4 is a tool, 5 is a claw, 6 is a float screw, 7 is a guide block, 16 is a cap as an annular fixing member, 18 is a retaining ring as an elastic body, and 25 is a taper bush.

Claims (1)

[Claims] 1. A shaft to which power is transmitted, a taper bush that is rotatable with respect to the shaft and is coupled in the axial direction, and a tightening for performing radial movement with rotation of the taper bush with respect to the shaft. In a tightening tool provided with a pawl, an annular fixing member for axially coupling the taper bush and the shaft is arranged in the opening of the taper bush that engages the pawl on the inner surface, and the opening end of the taper bush is also provided. A tightening tool characterized in that a retaining ring for retaining the annular fixing member is engaged with a groove formed on the inner peripheral surface of the fastening member.