JPH07299742A - Tool fastening device - Google Patents

Abstract

PURPOSE:To generate a sufficient fastening only by hand and provide possibility of additional tightening certainly. CONSTITUTION:A grip 5 is secured to a clamp nut 3 through an O-ring 4, and a holder ring 6 is fitted in the grip 5. An outer clamp member 9 prevented from slipping off by a stop ring 8 is inserted to the clamp nut 3. Grooves are provided at tapered surfaces of the holder ring 6 and outer clamp member 9. A roller 11 where a left-hand threaded portion to be engaged by the grooves is formed on the tapered surface, is installed rotatably between the outer clamp member 9 and holder ring 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tightening device for a tool, and more particularly to a tightening device for attaching and detaching a disk-shaped tool such as a grinder grindstone without an auxiliary tool.

[0002]

2. Description of the Related Art Generally, a processing device for rotating a tool such as a grinder to perform work is widely known. In such a device, the rotary tool is attached by a detaching device.

FIG. 4 is a cross-sectional view of a conventional attaching / detaching device, and FIG. 5 is a cross-sectional view taken along the line VV in FIG.
issue). In the figure, reference numeral 101 is a ring member, and this ring member 101 has three radial pins 102, 102, 1
02 is embedded so as to project inward. In addition, the support member 1 has a gap 104 inside the ring member 101.
03, 103, 103 are provided. This gap 10
A stopper 105 is provided at an appropriate position within the coil 4, and the coil spring 1 is provided between the stopper 105 and the radial pin 102.
06 is provided. A ball 107 is rotatably arranged on the opposite side of the radial pin 102 and the stopper 105. Further, the ball 1 is provided inside the ring member 101.
A notch 101a with which 07 can be engaged is formed. Further, a clamp nut 108 that can be screwed into the spindle 109 is inserted into the inner diameter portion of the support body 103. Further, as shown in FIG. 5, a slide member 110 is slidably inserted into the main body portion 108a of the clamp nut 108. This slide member 110 is a rotary tool 11
1, and the rotary tool 111 is sandwiched between it and the inner flange portion 113 of the gear shaft 112.

In the attachment / detachment device thus constructed,
The operation of mounting the attachment / detachment device on the spindle 109 will be described below. First, the main body 108a of the clamp nut 108 is engaged with the spindle 109, and the ring member 101 is rotated, whereby the clamp nut 1
Screw 08. Then, as shown in FIG. 5, the slide member 110 stops at the position where it abuts on the rotary tool 111,
Temporary tightening is done. Next, when a motor (not shown) is operated to rotate the spindle 109, the spindle 109 rotates in the direction in which the clamp nut 108 is tightened, so that the tightening is performed and the mounting of the rotary tool 111 is completed.

However, in the above-mentioned structure, when the rotary tool is mounted, the ball is located in the notch inside the ring member, so that it cannot be tightened only by hand tightening, and the additional tightening by the motor is performed. Is required. Further, since the slide member and the clamp nut are pressed through the support, the number of parts is increased and the processing becomes complicated.

Therefore, in recent years, an attaching / detaching device as shown in FIG. 6 has been proposed (Japanese Patent Application No. 3-16893). Reference numeral 201 in the drawing denotes a gear shaft, and a spindle 202 is attached to an end portion of the gear shaft 201. Also, the gear shaft 2
An inner flange portion 201a is provided at the end portion of 01 so as not to rotate. One surface side of the rotary tool 203 is in contact with the inner flange portion 201a, and the tightening body 204 is in contact with the other surface side of the rotary tool 203. Reference numeral 205 in the figure denotes a clamp nut, and this clamp nut 205 has a body portion 205b having a screw portion 205a.
And a flange portion 205c formed at the end of the main body portion 205b. Also, this flange portion 2
A tapered surface portion 205d is formed on the right side of 05c in FIG. Further, a slidable ring-shaped tool pressing member 206 is penetrated through the outer peripheral surface of the main body 205b,
The C-ring 207 that engages with the circumferential groove 205e formed on the outer peripheral surface of the body portion 205b prevents the tool pressing member 206 from falling off the body portion 205b. Further, the taper surface portion 205d of the tool pressing member 206
A taper surface portion 206a is formed on the side facing (left side in FIG. 6). Further, the tapered surface portion 205d of the clamp nut 205 and the tapered surface portion 206 of the tool pressing member 206 are
Three spheres 208 are provided between a and a (FIG. 7), and are held by the ring member 209 so as not to fall off. This ring member 209 is a clamp nut 2
No. 05 is provided over the outer peripheral portions of the flange portion 205c and the tool pressing member 206 via O-rings 210 and 211. In addition, on the inner peripheral portion of the ring member 209,
As shown in FIG. 7, three stoppers 209a and 209 are provided.
a and 209a are provided so as to project in the centripetal direction, and a spherical body 208 and a spring 212 for pressing the spherical body 208 against the stopper 209a are provided between the adjacent stoppers 209a and 209a. Further, the inner peripheral surface 209b of the ring member 209 has an arc shape in which the size of the inner diameter changes between the adjacent stoppers 209a. The spherical body 208 is configured to be maximized in diameter at the position where it is pressed by the spring 212 and comes into contact with the stopper 209a (the end portion in the clockwise direction in FIG. 7).

Then, the screw portion 205a of the clamp nut 205 is screwed onto the spindle 202, and rightward in FIG. 6 until the tool pressing member 206 contacts the rotary tool 203.
The tightening body 204 is advanced. During this approaching movement, the sphere 20
8, the stopper 209a is a spring 212 as shown in FIG.
Being pressed by. Then, the tool pressing member 206
When the rotary tool 203 contacts the clamp nut 205,
Screwing is completed. At this time, the spherical body 208 is the tapered surface portion 205d of the flange portion 205c of the clamp nut 205.
And the tapered surface portion 206a of the tool pressing member 206. In this state, the ring member 209 is further rotated in the clockwise direction in FIG. 7 against the biasing force of the spring 212. At this time, the sphere 208 has the flange portion 20.
5c and the tapered surface portions 205d, 20 of the tool pressing member 206
Since it is sandwiched by 6a, the spherical body 208 does not cooperate with the ring member 209, and only the ring member 209 rotates. Then, the spherical body 208 moves in the centripetal direction along with the change in the inner diameter of the inner peripheral surface 209b of the ring member 209. Further, along with this movement in the centripetal direction, the tool pressing member 206 moves the flange portion 2 of the clamp nut 205.
The movable tool 203 moves in a direction away from 05c (to the right in FIG. 6) and the gap between the tool pressing member 206 and the inner flange 201a is narrowed, so that the rotary tool 203 is strongly pressed and the fixing of the rotary tool 203 is completed.

[0008]

However, with the above-mentioned structure, the sphere is not a perfect rolling motion, and the number of spheres is limited. Therefore, the tightening force is weak and sufficient retightening is required. I can't do it. Further, since the rotation angle of the ring member at the time of additional tightening is small, a strong force is required, and there is a problem that manual tightening cannot sufficiently tighten.

The present invention has been made in view of the above problems, and provides a tightening device for a tool, which can achieve sufficient tightening only by hand tightening and can reduce the number of parts. With the goal.

[0010]

According to the present invention, there is provided a first clamp member provided on a rotating shaft for rotating a tool, a screwing member screwed to the rotating shaft, and a rotating member with respect to the screwing member. Between the second clamp member and the grip member, a grip portion that is movably provided, a second clamp member that is rotationally restricted with respect to the screw member, and that is movably provided in the axial direction. An intervening truncated cone-shaped roller member is provided, and a taper surface corresponding to a side surface of the roller member is formed on each of the second clamp member and the grip member. On one side, a spiral or circumferential groove is formed,
Another feature is that a protrusion that is screwed into the groove is formed.

[0011]

Operation: The grip portion is rotated by screwing the screwing member onto the rotating shaft. Then, the screwing member rotates together with the grip portion via the friction member, and advances. Then, the tool can be clamped by the first clamp member and the second clamp member. Further, when the grip portion is rotated, the roller member moves in the rotation center direction of the rotation shaft due to the threaded state of the groove portion and the protruding portion. At this time, since the second clamp member also has a tapered surface, the tapered surface moves the second clamp member in the direction of pressing the tool, and the first clamp member and the second clamp member move the tool. It can be clamped or fixed by tightening.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a cross-sectional view of a tool tightening device according to the present invention. The upper part of FIG.
The lower middle part shows the state after retightening. In the figure, reference numeral 1 is a rotary shaft, and an inner clamp member 2 is inserted in the rotary shaft 1 in a state in which rotation with respect to the rotary shaft 1 is restricted.
A clamp nut 3 is detachably engaged with the threaded portion 1a of the rotary shaft 1. A grip 5 is provided on the outer circumference of the clamp nut 3 via an O-ring 4. When the grip 5 is rotated, the grip 5 and the clamp nut 3 rotate integrally with the O-ring 4 when the grip 5 is rotated, but the grip 5 is rotated by a force larger than a certain size. When it is made to rotate, it is made of a friction material that gives a frictional force such that only the grip 5 rotates, for example, an elastic material such as rubber. Further, a holder ring 6 is fitted inside the grip 5, and a plurality of steel balls 7, 7, ... (See FIG. 2) are interposed between the holder ring 6 and the clamp nut 3. It constitutes the bearing. Further, the clamp nut 3 has an outer clamp member 9 which is prevented from falling off by a stop ring 8.
Are movably provided in the axial direction. Further, since the outer clamp member 9 is engaged with the cutout portion 3a formed in the clamp nut 3, rotation of the outer clamp member 9 with respect to the clamp nut 3 is restricted. Also, the holder ring 6
A disc-shaped retainer 10 is arranged between the outer clamp member 9 and the outer clamp member 9, as shown in FIG. A plurality of cutouts 10a are formed in the retainer 10, and a truncated conical roller 11 is housed in each of the plurality of cutouts 10a.

FIG. 3 is a partially enlarged sectional view showing the mounting portion of the roller 11. Tapered surfaces 6a and 9a tapering toward the center of rotation of the rotary shaft 1 (FIG. 1) are formed on the surfaces of the holder ring 6 and the outer clamp member 9 which face each other, and these tapered surfaces 6a and 9a are respectively formed. Circumferential grooves 6b and 9b are engraved in the. In addition, the roller 11 having a truncated cone shape
A left-hand thread portion 11a that engages with the grooves 6b and 9b is engraved on the side surface of the.

The operation of the tool tightening device thus configured will be described. Insert the grindstone 12 that is a tool into the threaded portion 1a of the rotary shaft 1 and further outside (left side in FIG. 1).
Tighten the clamp nut 3 by screwing. At this time, the operator rotates the grip 5, but the clamp nut 3 rotates integrally with the grip 5 by the O-ring 4 which is a friction member. Then, the grindstone 12 is held between the inner clamp member 2 and the outer clamp member 9. As a result, the whetstone 12
Is temporarily clamped. Further, by rotating the grip 5 with a force larger than the frictional force of the O-ring 4, the grip 5 and the holder ring 6 fitted to the grip 5 rotate. As the holder ring 6 rotates, the roller 11 engaged with the groove 6b formed in the tapered surface 6a of the holder ring 6 moves in the centripetal direction (upward in FIG. 3A) while rotating. (FIG.3 (b)).
For this reason, since the roller 11 is in contact with the tapered surfaces 6a and 9a, the outer clamp member 9 is pressed to the right in FIG. 3B, and the grindstone 12 can be clamped more firmly. Can be tightened (Fig. 3
(B)). In particular, in this embodiment, the left screw portion 11a of the roller 11 and the grooves 6b and 9b are tightened, so that a more reliable tightening operation can be performed.

In the above embodiment, the case where the circumferential grooves 6b and 9b are formed in the holder ring 6 and the outer clamp member 9 has been described, but the circumferential grooves are not necessarily required, and for example, the holder is used. A right spiral groove may be formed in the ring 6 and a left spiral groove may be formed in the outer clamp member 9. On the contrary, a left spiral groove may be formed in the holder ring 6 and a right spiral groove may be formed in the outer clamp member 9. Further, when the holder ring 6 and the outer clamp member 9 are formed with different spiral grooves on the left and right respectively, a circumferential protrusion may be formed on the roller 11. By appropriately changing the shapes of the groove and the protrusion in this way, the movement ratio of the roller 11 in the centripetal direction (upward in FIG. 3A) can be adjusted.

Further, in the above-described embodiment, both the temporary clamping operation and the retightening operation are performed only by the operation of the grip, but the present invention is not limited to this, and the temporary clamping operation is the operation of rotating the clamp nut. Alternatively, the tightening operation can be performed by rotating the grip. In this case, a friction member such as an O-ring for preventing rotation and a rubber knock is not required.

[0017]

As described above, according to the present invention, because of the above-mentioned configuration, the mounting work can be performed manually without the need for additional tightening by the motor. Further, the second clamp member is moved by the movement of the frustoconical roller member, and the tightening is performed, so that the operation resistance can be reduced and the operability can be improved. Further, the contact area of the roller member can be increased by making the shape tapered, and a strong tightening force can be generated. Further, since the groove and the protrusion are engaged with each other, it is possible to reliably move the roller member.

[Brief description of drawings]

FIG. 1 is a front sectional view of a tool tightening device according to the present invention.

FIG. 2 is a side sectional view of a tool tightening device according to the present invention.

FIG. 3 is an enlarged sectional view of an essential part of a tool tightening device according to the present invention.

FIG. 4 is a cross-sectional view of a conventional tool fastening device.

FIG. 5 is a cross-sectional view of a conventional tool fastening device.

FIG. 6 is a cross-sectional view of a conventional tool fastening device.

FIG. 7 is a cross-sectional view of a conventional tool fastening device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotating shaft 2 ... Inner clamp member (first clamp member) 3 ... Clamp nut (screw member) 4 ... O-ring (friction member) 5 ... Grip (grip member) 6 ... Holder ring (grip member) 6a ... Taper Surface 6b ... Groove (groove portion) 9 ... Outer clamp member 9a ... Tapered surface 9b ... Groove (groove portion) 11 ... Roller (roller member) 11a ... Left screw portion (projection portion)

Claims (1)

[Claims] 1. A first clamp member provided on a rotary shaft for rotating a tool, a screw member screwed on the rotary shaft, and a grip portion rotatably provided on the screw member. , A second clamp member which is rotationally restricted with respect to the screw member and is movable in the axial direction, and has a truncated cone shape interposed between the second clamp member and the grip member. A roller member, wherein each of the second clamp member and the grip member has a tapered surface corresponding to a side surface of the roller member, and one of the tapered surface and the roller member has a spiral shape. Alternatively, the tool tightening device is characterized in that a groove portion on the circumference is formed and a projecting portion that is screwed into the groove portion is formed on the other side.