JPH0829441B2 - Tool chuck - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tool chuck used for holding and fixing various tools such as a bit of an electric drill and a bit of an electric screwdriver.

(B) Conventional Technology Conventionally, as the above-mentioned tool chuck, for example, a nut ring attached to the chuck body is normally and reversely rotated by a rotating operation of an operation ring, and a plurality of chuck claws screwed with the nut ring are provided. There is a tool chuck (Japanese Utility Model Laid-Open No. 63-189509) in which a tool is clamped and fixed by each of these chuck claws by screw feeding in the expansion / contraction direction.

(C) Problems to be Solved by the Invention However, in the above-mentioned tool chuck, since the turning force of the operation ring is directly transmitted to each chuck claw to tighten and fix the tool, the torque at the time of tightening the tool is the turning force of the operation ring. Since it is structurally difficult to tighten and fix the tool with a torque higher than the turning power, it is easy for rattling or looseness to occur in the tool that is clamped and fixed, and the tool falls off during work. There is a problem that sometimes.

According to the present invention, when the tool is clamped, the rotation transmitting body of the differential mechanism is decelerated and rotated,
It is an object of the present invention to provide a tool chuck that can obtain a torque higher than that of rotating an operation ring and can firmly tighten and fix a tool only by relatively rotating the operation ring and a chuck body.

(D) Means for Solving the Problems The present invention is a tool chuck that expands and contracts a plurality of chuck claws attached to a chuck body in a tool clamping direction by rotating a nut ring forward and backward by an operation ring. And a differential mechanism for decelerating the rotation of the operating ring to the nut ring to transmit power, between the operating ring and the nut ring, and the external mechanism that fixes the differential mechanism to the operating ring. A rotation transmission body supported so as to be capable of transmitting power to the nut ring, and an internal transmission body held so as to be rotatable so as to be in contact with each other in the axial direction, and the internal transmission body is
A tool chuck provided with a fixing means for allowing the external transmission body and the rotation transmission body to integrally rotate when the load resistance during the rotation operation is small, and for fixing the rotation in place by the large load resistance when the tool is clamped. Is characterized in that.

(E) Action In the tool chuck of the present invention, when the tool is tightened and fixed, the operation ring, the chuck body, and the tool are relatively rotated in the tool tightening direction, so that the load resistance is small during the rotating operation until the tool is clamped. The operating ring and each element of the differential mechanism are integrally rotated, and the plurality of chuck claws are swiftly and tightly slid by the screw feed of the nut ring to clamp the tool.

In this clamping, when the rotation of the internal transmission body constituting the differential mechanism is fixed by the fixing means due to the load resistance during the clamping of the tool, the rotation of the external transmission body due to the rotation of the operation ring is transmitted to the rotation transmission body. As a result, the rotation transmitting body rolls on the transmitting surface of the internal transmitting body, and the movement of the rotating transmitting body becomes half of the rotation of the external transmitting body due to this rolling, which is lower than the rotational speed of the operating ring. The rotation transmitting member is decelerated and moves, and this movement causes the nut ring to rotate in the tightening direction.

Therefore, by decelerating the rotation transmitting body, the rotational force of the operating ring is increased in torque, a high torque is applied to the nut ring, and the tool is firmly tightened and fixed by the plurality of chuck claws.

On the other hand, when releasing the tightening fixation of the tool, by rotating the operation ring and the chuck body relatively in the loosening direction,
While the internal transmission body of the differential mechanism is rotationally fixed, a high torque is applied by the differential mechanism and the nut ring can be rotated in the loosening direction. The load resistance is small, and the operation ring and each element of the differential mechanism are integrally rotated to rapidly expand and slide each of the plurality of chuck claws to release the holding and fixing of the tool.

(F) Effect of the Invention According to this invention, when the tool is clamped, decelerating movement of the rotation transmitting body of the differential mechanism provides torque higher than the force of directly rotating the nut ring by the operation ring. The tool can be firmly tightened and fixed by a simple operation of simply rotating the operation ring and the chuck body relative to each other.

Moreover, the load resistance is small during the rotation operation until the tool is clamped and after the tightening is released, and the operation ring and each element of the differential mechanism can be integrally and normally rotated. The screw feeding of the nut ring allows the plurality of chuck claws to be rapidly expanded / contracted and slid so that the tool can be clamped / fixed or unfixed, which is excellent in operability.

(G) Embodiment of the Invention One embodiment of the present invention will be described in detail below with reference to the drawings.

The drawings show a tool chuck used for holding and fixing various tools such as an electric drill and an electric screwdriver. In FIGS. 1 and 2, the tool chuck 1 is an intermediate portion of a chuck body 2 formed in a cylindrical shape. Three guide holes 3 are formed on the outer peripheral surface in an oblique direction that gathers toward the center of the tip side opening, and three chuck claws 4 can be expanded and contracted in these guide holes 3. Have been inserted into.

On the other hand, a rotating shaft such as an electric drill or an electric screwdriver is connected and fixed to the base end side opening of the chuck body 2.

An annular notch 5 is formed on the outer peripheral surface of the intermediate portion of the chuck body 2 by cutting out a part of the peripheral surface of each guide hole 3 ...
The nut ring 6 formed so as to be divided into two is provided with an annular cutout 5
The female screw 6a screwed on the inner peripheral surface of the nut ring 6 and the male screw 4a screwed on the outer peripheral surface of the base end portion of each chuck claw 4 are screwed together. This nut ring 6
The fixing ring 7 is press-fitted and fixed to the outer peripheral surface of the tip end of the above so as to be rotatable.

That is, by rotating the nut ring 6 in the normal and reverse directions, the chuck claws 4 ... Are screw-fed in the expansion / contraction direction along the guide holes 3, ... To pinch.

A holding ring 9 having a U-shaped cross section is fixed to the outer peripheral surface of the base end portion of the chuck body 2 described above, and a cylindrical operation ring 8 is rotatable on the outer peripheral surface of the intermediate portion of the chuck body 2. The outer peripheral surface of the operation ring 8 and the inner peripheral surface of the open end side of the holding ring 9 are rotatably fitted and supported by loose fitting, and the outer peripheral surfaces of the rings 8 and 9 are Knurled wheels 8a and 9a are engraved respectively.

A differential mechanism 10 for transmitting the rotational force of the operating ring 8 to the nut ring 6 is interposed between the operating ring 8 and the nut ring 6.

That is, an outer ring 11 constituting the differential mechanism 10 is rotatably loosely fitted on the outer peripheral surface of the intermediate portion of the nut ring 6 described above, and a metal-made member is provided between the facing surfaces of the outer ring 11 and the fixed ring 7. A large number of spheres 12 are rotatably held, and a plurality of protrusions 11a are formed on the outer peripheral surface of the outer ring 11,
A plurality of groove portions 9b formed on the inner peripheral surface of the operation ring 8 are engaged and fixed by rotation, and are engaged so as to be movable in the axial direction.

A differential mechanism is provided on the outer peripheral surface of the inner end portion of the nut ring 6 described above.
The retainers 13 constituting the unit 10 are integrally fixed, and 16 spherical holding portions 13a are formed in the circumferential direction of the retainer 13 at predetermined equal intervals, and these spherical holding portions 13a are made of metal. Each sphere 14 is held so as to be rollable.

An inner ring 16 constituting the differential mechanism 10 is rotatably held between the retainer 13 fixed to the nut ring 6 and the step portion 15 formed on the outer peripheral surface of the intermediate portion of the chuck body 2. The inner ring 16 is constantly urged by a coil spring 17 housed and held on the inner peripheral surface of the base end portion of the retaining ring 9 in a direction in which it is pressed against each sphere 14 of the retainer 13 fixed on the nut ring 6. There is.

The above-mentioned coil spring 17 is compressed and held between the spring stopper 18 fixed to the inner peripheral surface of the inner end portion of the operation ring 8 and the pressing plate 19 in contact with the inner ring 16, and the inner ring 16 and the pressing plate 19 are connected to each other. A large number of metallic spheres 20 are rotatably held between the facing surfaces.

The coil spring 17 includes a fixed ring 7 fixed to the nut ring 6 with respect to the inner peripheral surface of the distal end portion of the operation ring 9.
, Each of the spheres 12, the outer ring 11, each of the spheres 14 held by the retainer 13, the inner ring 16, each of the spheres 20 and the pressing plate 19 are constantly in pressure contact with each other in the axial direction.

A leaf spring 21 is fixed to the inner peripheral surface of the operation ring 8 so as to face the outer peripheral surface of the inner ring 16, and when the inner ring 16 is allowed to rotate in the forward and reverse directions, a protrusion formed on the leaf spring 21. Part 21a
And the notch surface 16a formed on the outer peripheral surface of the inner ring 16 are engaged with each other to rotate the operating ring 8 and the inner ring 16 in the same direction, and the inner ring 16 is rotationally fixed to release the engagement. The rotation of only the operation ring 8 is allowed, and the notch feel is intermittently imparted by the engagement between the protrusion 21a of the leaf spring 21 and the notch surface 16a.

The illustrated embodiment is configured as described above, and
The action and operation when the tool A is clamped by the tool chuck 1 will be described.

First, the operation ring 8 fixed to the chuck body 2 is held by the left hand, the holding ring 9 is held by the right hand, and the tools A are clamped by relatively rotating each of these rings 8, 9 in the tool clamping direction. The load resistance applied to the nut ring 6 is small during the rotation operation up to, and the outer ring of the differential mechanism 10 is axially pressed against the rotation direction of the operation ring 8.
11, each sphere 14 held by the retainer 13, and the inner ring
16 is rotated integrally with each other, and the plurality of chuck claws 4 ... Are swiftly compressed and slid by the screw feed of the nut ring 6 to clamp the tool A.

Due to the load resistance applied at this time when the tool is clamped, as shown in FIG. 3, the respective male screws 4a ... Threaded onto the three chuck claws 4 ... 6a
The outer ring 11 of the differential mechanism 10 that is axially pressed against the nut ring 6 is retracted in the axial direction by the backlash dimension of the and the fixed ring 7 fixed to the nut ring 6,
The spheres 14 held by the retainer 13 and the inner ring 16 are moved backward in the axial direction, and the inner peripheral edge portion of the inner ring 16 is pressed against the step portion 15 of the chuck body 2 to be rotationally fixed.

That is, when the inner ring 16 is fixed to the chuck body 2, the rotation of the outer ring 11 due to the rotation of the operation ring 8 is transmitted to the sphere 14, and the sphere 14 is rotated on the transmission surface (contact surface) of the inner ring 16. The movement of the sphere 14 due to this rolling, that is, the movement of the retainer 13 is caused by the outer ring.
It becomes 1/2 of 11 rotations and is decelerated.

FIG. 5 shows this deceleration action, and in order to move the sphere 14 held by the retainer 13 by the distance L from the point α to the point β of the inner ring 16 in FIG. Also the rolling transmission points a to b for moving the sphere 14 by the distance L.
Distance L is required.

Then, when the outer ring 11 is rotated to roll the spherical body 14 and the spherical body 14 is moved while rolling from the point α to the point β of the inner ring 16, as shown in FIG. sphere
The transfer point of the outer ring 11 with respect to 14 also moves from the point a to the point b, and as a result, the moving distance of the transfer point a of the outer ring 11 with respect to the transfer point α of the inner ring 16 becomes 2L.

This means that in order to move the sphere 14 (including the retainer 13) by the distance L, the rotation amount of the outer ring requires the distance 2L. In other words, the movement distance 2L due to the rotation of the outer ring 11 is By rolling the sphere 14, the sphere 14 is decelerated to a distance L of 1/2, and the sphere 14 is moved. Therefore, the retainer 13 holding the sphere 14 rotates the nut ring 6 at a decelerated rotation of ½. Become.

Therefore, by decelerating the differential mechanism 10, the operation ring 8
The torque of the rotation power of is increased and applied to the nut ring 6,
As shown in FIG. 1, the tool A is firmly tightened and fixed by the plurality of chuck claws 4.

On the other hand, when the tightening fixation of the tool A is released, the inner ring 16 of the differential mechanism 10 is rotationally fixed by rotating the chuck body 2 and the operation ring 8 relatively in the loosening direction. The high torque acts while the nut ring 6
Can be easily rotated in the loosening direction, the load resistance is small during the rotating operation after the tightening is released, and the operation ring 8, the outer ring 11 of the differential mechanism 10, each sphere 14, ...
16 is integrally rotated to rapidly expand and slide each of the plurality of chuck claws 4 ..., and the clamping and fixing of the tool A is released.

As described above, when the tool A is clamped, the torque of the operation ring 8 is increased by the differential mechanism 10, so that the nut ring 6 can be rotated with this high torque to firmly tighten the tool A. The tool A can be operated by a simple operation of rotating the operation ring 8 and the chuck body 2 relative to each other.
Can be firmly tightened and fixed.

Moreover, during the turning operation until the tool A is clamped,
The load resistance is small during the rotation operation after the tightening is released, and the respective elements of the differential mechanism 10 can be integrally rotated in the forward and reverse directions in accordance with the rotation direction of the operation ring 8. The tool A can be clamped or released by rapidly expanding and contracting each of the plurality of chuck claws 4 by feeding, and the operability is excellent.

The chuck body 2 and the operation ring 8 described above may be relatively rotated by forward / reverse rotation of an electric drill or an electric driver engaged with the base end side opening of the chuck body 2.

In the correspondence between the configuration of the present invention and the above-described embodiment, the differential mechanism of the present invention corresponds to the differential mechanism 10 of the embodiment, and hereinafter, similarly, the external transmission body corresponds to the external ring 11. The rotation transmission body corresponds to the sphere 14 and a rotation gear 22 described later, the internal transmission body corresponds to the inner ring 16, and the fixing means corresponds to the step portion 15 to which the inner ring 16 is pressed. The present invention is not limited to the configurations of the above-described embodiments.

For example, as shown in FIG. 4, the sphere 14 of the above-described embodiment is used.
In place of the above, a plurality of rotary gears 22 ... Are pivotally supported on the outer peripheral surface of the base end portion of the nut ring 6, and these rotary gears 22 ... The differential mechanism 10 may be configured by meshing with the gear surfaces 16b engraved on the nut ring 6, respectively. In this case, the turning force of the operating ring 8 is applied to the nut ring 6 via the differential mechanism 10. Since the drive is surely transmitted, the drive is actually transmitted, the loss of the tightening force is small, the tool A can be more firmly fixed, and the effect equal to or more than that of the above-described embodiment can be obtained. The elements having the same functions as those of the differential mechanism 10 of the above-described embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a vertical sectional side view of a tool chuck, Fig. 2 is an enlarged vertical sectional side view showing a differential mechanism before or after releasing a tool, and Fig. 3 is a tool clamping. FIG. 4 is an enlarged vertical side view showing the differential mechanism at the time, FIG. 4 is an enlarged vertical side view of the differential mechanism showing another embodiment, and FIG. 5 is a development explanatory view for stopping the deceleration operation of the differential mechanism. A: Tool, 1 ... Tool chuck, 2 ... Chuck body, 4 ... Chuck claw, 6 ... Nut ring, 8 ... Operation ring, 10 ... Differential mechanism, 11 ... External ring, 11b ... Gear surface, 14 …… Sphere 15 …… Step, 16 …… Inner ring 16b …… Gear surface, 22 …… Rotating gear

Claims (1)

[Claims] 1. A plurality of chuck claws are attached to the center of the tip side of a chuck body so as to be able to expand and contract, and a nut ring screwed to each of these chuck claws is normally and reversely rotated by an operation ring to hold the tool in the tool holding direction. Is a tool chuck that expands and contracts each chuck claw, and a differential mechanism that decelerates the rotation of the operation ring to the nut ring and transmits power is provided between the operation ring and the nut ring. An external transmission body that fixes the moving mechanism to the operation ring,
A rotation transmitting body supported so as to be able to transmit power to the nut ring and an internal transmitting body which is rotatably held on the chuck body are arranged in axial contact with each other, and the internal transmitting body is rotated. When the load resistance during operation is small, the external rotation body and the rotation transmission body are allowed to rotate integrally,
A tool chuck equipped with fixing means that rotates and fixes it in a fixed position due to a large load resistance when the tool is clamped.