JP2005349504A - Fixing nut of article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fixing nut for fixing a grinding wheel to a spindle of a grinder, simplifying the operation of the fixing nut by loosening the nut chamfered due to working resistance applied to the grinding wheel with small force. <P>SOLUTION: When a piston 17 is advanced into a pressure chamber 14 between a nut body 11 having a female screw part 11b and a pressing plate 12, and an operating plate 13 is turned in the loosening direction, the piston 17 is moved backward to lower the pressing force of the pressing plate 12, thereby eliminating chamfering in the axial direction of the screw. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a fixing nut for fixing a disc-shaped grinding wheel to a spindle of a disc grinder (hereinafter simply referred to as a grinder) as a hand-held tool, for example, so that it can be loosened with a small force. The present invention relates to a fixing nut for an article having a loosening assist function.

For example, in the above grinder, after a disc-shaped grinding wheel is set on a spindle rotated by a motor, a fixing nut is tightened on a male screw portion of the spindle, and the grinding wheel is connected to a flange portion of the spindle and the fixing nut. It can be fixed by being sandwiched between them.
When the grinding wheel fixed in this way is pressed against the work piece, the inertia at the time of starting the spindle and the grinding resistance applied to the grinding wheel are tightened against the fixed nut, so that the fixed nut is used by the user. When the grinding wheel is removed from the spindle, it becomes difficult for the user to manually loosen the fixing nut. Conventionally, measures against this problem have been taken.
For example, the fixing nut 30 described in the pamphlet of International Publication No. 01/10600 is brought into contact with a grinding wheel 31 set on the flange portion 32a of the spindle 32 as shown in FIG. 6 using FIG. 1 of the pamphlet. And a nut main body 33 that is gripped and rotated by a user. A pressure chamber 34 containing a pressure medium such as silicon oil is provided between the pressing plate 35 and the nut body 33.
The nut body 33 is provided with a piston plate 37 that changes the volume of the pressure chamber 34 by being displaced in the axial direction (vertical direction in the figure) and a push button 36 that is pushed by the user. A steel ball 39 and a compression spring 40 are interposed between the push button 36 and the piston plate 37.

The push button 36 is provided with two engaging recesses (a shallow engaging recess 37a and a deep engaging recess 37b) having different depths in the radial direction. In the state before the fixing nut 30 is tightened, when the push button 36 is not pushed in, the push button 36 is returned to the direction away from the piston plate 37 by the compression spring 40, and the steel ball is inserted into the shallow engagement recess 37a. 39 is in the fitted state. In this state, the piston plate 37 approaches the pressing plate 35 and is held in a state where the volume of the pressure chamber 34 is reduced. In this state, by tightening the fixing nut 30 into the external thread portion of the spindle 32, the grinding wheel 31 can be sandwiched and fixed between the flange portion 32a of the spindle 32.
In a state where the grinding wheel 31 is fixed, when the push button 36 is pushed up against the compression spring 40 in order to loosen the fixing nut 30, the steel ball 39 is fitted into the deep engagement recess 37b. As a result, the piston plate 37 can be displaced in the direction in which the pressure chamber 34 is widened (downward in the drawing), and the pressure in the pressure chamber 34 is reduced. As the pressure in the pressure chamber 34 decreases, the pressing force of the pressing plate 35 against the grinding wheel 31 decreases, thereby loosening the tightening state (biting state) of the fixing nut 30 with respect to the spindle 32 in the screw shaft direction. The fixing nut 30 could be loosened with a smaller force.
International Publication No. 01/10600 Pamphlet

However, according to the above-described conventional fixing nut 30, the push button 36 is pushed against the compression spring 34 to release the pressing state in the screw shaft direction of the pressing plate 35 against the grinding wheel 31. Initially, the fixing nut 30 had to be rotated in the loosening direction with the push button 36 being pushed in. For this reason, it is difficult for the user to loosen and operate the fixing nut 30 with one hand. In some cases, it is necessary to push the push button 36 with one hand and rotate the nut body 33 in the loosening direction with the other hand. In this respect, the conventional fixing nut 30 has poor operability.
An object of the present invention is to provide a fixing nut with good operability that can be easily loosened and operated with one hand.

For this reason, this invention was set as the fixing nut of the structure described in each claim of a claim.
According to the fixing nut of claim 1, when the operation plate is rotated in the screw loosening direction, the piston moves backward due to the displacement of the cam portion with respect to the piston, thereby the amount of the piston entering the pressure chamber. , And the volume of the pressure chamber increases by the volume corresponding to this decrease, and as a result, the pressure in the pressure chamber decreases.
When the pressure in the pressure chamber decreases, the pressing force of the pressing plate against the article decreases, thereby loosening the tightening state of the nut body mainly in the screw axis direction with respect to the male screw portion, so that the operation plate is rotated as it is in the screw loosening direction. Accordingly, the fixing nut can be loosened with a smaller force against the male screw portion.
In this way, the operation plate is configured to loosen the pressing force against the article by the rotation of the operation plate. Therefore, the user can loosen the fixing nut only by performing an operation of rotating the operation plate in the screw loosening direction. This eliminates the need for troublesome operations such as pressing the push button with one hand and rotating with the other hand as in the prior art.

According to the fixing nut of claim 2, when the operation plate is rotated in the screw loosening direction, the cam portion is displaced with respect to the piston, so that the piston moves backward, thereby the amount of the piston entering the pressure chamber. , And the volume of the pressure chamber increases by a volume corresponding to this decrease, and as a result, the pressure in the pressure chamber decreases.
When the pressure in the pressure chamber decreases, the pressing force of the pressing plate against the processing tool decreases, and the tightening state of the nut body with respect to the male thread portion mainly in the screw axis direction is loosened. Therefore, the fixing nut can be loosened with a smaller force with respect to the male screw portion by directly rotating the operation plate in the screw loosening direction.
As described above, since the operation plate is rotated to loosen the pressing force of the pressing plate against the processing tool, the user can increase the tightening force in the screw shaft direction only by rotating the operation plate in the screw loosening direction. The fixing nut can be loosened with a small force. Therefore, the fixing nut that bites into the male screw part due to machining resistance, inertia at startup, etc., without the troublesome operation of pressing the push button with one hand and rotating with the other hand as in the past. It can be easily loosened with a small force.

Next, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows the periphery of the grinding wheel mounting portion of a grinder 1 to which a disc-shaped grinding wheel 2 is mounted using a fixing nut 10 of the present embodiment described below. The grinder main body is the same as the conventional one, and since there is no particular change in the present embodiment, illustration and explanation thereof are omitted. However, this grinder main body has an electric motor built in, and this electric motor is used as a drive source for the spindle. 3 rotates. In FIG. 1, only the tip side of the spindle 3 of the grinder 1 is shown.
A flange portion 3 a and a male screw portion 3 b are provided at the tip of the spindle 3. In the present embodiment, the male screw portion 3b is formed of a right screw. Therefore, if the fixing nut 10 is rotated clockwise with respect to the male screw portion 3b, the fixing nut 10 is fastened to the male screw portion 3b, and conversely if it is rotated counterclockwise, the fixing nut 10 is moved with respect to the male screw portion 3b. Relaxed.
The grinding wheel 2 has the male threaded portion 3b inserted into a mounting hole 2a provided at the center thereof, and one surface of the grinding wheel 2 is in contact with the flanged portion 3a with the inner flange 4 interposed therebetween. In this state, the male threaded portion 3b The fixing nut 10 is fastened to the end of the spindle 2 to fix it. Therefore, the grinding wheel 2 can be removed from the spindle 3 by loosening the fixing nut 10 with respect to the male screw portion 3b.
In the fixing nut 10 of the present embodiment, the grinding resistance applied to the grinding wheel 2 during grinding or the inertia when the grinding wheel 2 starts to rotate due to the spindle activation acts on the fixing nut 10 as an external force in the tightening direction. As a result, even if the tightening force of the fixing nut 10 on the male screw portion 3b is excessively strong, the user can easily loosen it with a small force (relaxation assist). Function).

Details of the fixing nut 10 are shown in FIGS. The fixed nut 10 includes a generally disc-shaped nut body 11, a pressing plate 12, and an operation plate 13. A pressure chamber 14 is provided between the nut main body 11 and the pressing plate 12 for containing a pressure medium such as silicon oil.
First, the nut main body 11 has a substantially disk shape, and a boss portion 11a is provided at the center thereof. A female screw portion 11b is formed on the inner peripheral side of the boss portion 11a. The male screw portion 3b of the spindle 3 is screwed into the female screw portion 11b.
The pressing plate 12 is assembled to the inner surface side (the upper surface side in FIG. 2) of the nut body 11. The pressing plate 12 has an annular shape and is supported via a boss portion 11a of the nut body 11 so as to be movable in a certain range in the axial direction. Further, the nut body 11 is formed with a cylinder portion 11d and a cylindrical wall portion 11h, each having a cylindrical shape, arranged side by side in the circumferential direction. A columnar engagement protrusion 12a provided on the pressing plate 12 is inserted on the inner peripheral side of the cylindrical wall portion 11h. The engaging protrusion 12a is inserted into the cylindrical wall portion 11h so as to be displaceable in the axial direction. The relative rotation of the pressing plate 12 with respect to the nut main body 11 is restricted by inserting the engaging protrusion 12a into the cylindrical wall portion 11h, so that the pressing plate 12 and the nut main body 11 always rotate integrally. ing.
On the outer periphery of the nut main body 11, an outer peripheral wall portion 11f standing on the inner surface side is formed over the entire periphery. The presser plate 12 is fitted between the outer peripheral wall portion 11f and the boss portion 11a and is assembled to the nut body 11. A seal ring 20 is attached to the outer peripheral surface of the pressing plate 12. The seal ring 20 provides a liquid-tight seal between the outer peripheral side of the pressing plate 12 and the outer peripheral wall portion 11 f of the nut body 11. A seal ring 21 is also attached to the inner peripheral surface of the pressing plate 12. The inner peripheral side seal ring 21 provides a liquid-tight seal between the inner peripheral side of the pressing plate 12 and the boss portion 11a.
A range between the nut body 11 and the pressing plate 12 and sealed by the seal rings 20 and 21 is a pressure chamber 14. The pressure chamber 14 is filled with silicon oil.
Displacement in the screw shaft direction (vertical direction in FIG. 2) of the pressing plate 12 is restricted by a retaining ring 16 attached to the outer peripheral side of the boss portion 11a. The retaining plate 16 prevents the pressing plate 12 from being detached from the boss portion 11a.
The operation plate 13 is assembled to the outer surface side (the lower surface side in FIG. 2) of the nut body 11. The operation plate 13 also has a generally annular shape, and is supported so as to be rotatable relative to the nut body 11 via a boss portion 11 a of the nut body 11. Further, the operation plate 13 is sandwiched by a retaining ring 18 attached to the outer peripheral side of the boss portion 11a, and is assembled so as not to move in the screw shaft direction in a state of being superimposed on the outer surface of the nut body 11.

On the outer surface of the nut body 11 and around the boss portion 11a, two wall portions 11ca and 11cb are formed over the entire circumference at a constant interval. A compression spring 15 is accommodated in a spring accommodating portion 11c formed between the two wall portions 11ca and 11cb. The spring accommodating portion 11c is covered with the operation plate 13 so that the accommodated compression spring 15 does not come off. Two seal rings 23 and 24 are attached to the inner surface of the operation plate 13. The two seal rings 23 and 24 are interposed on the inner peripheral side and the outer peripheral side of the spring accommodating portion 11c, so that the inside of the spring accommodating portion 11c is sealed from the outside to prevent foreign matter from entering. .
As shown in FIG. 3, a wall portion 11g is formed at one place in the circumferential direction of the spring accommodating portion 11c. The compression spring 15 is accommodated in the spring accommodating portion 11c in a state where one end side is in contact with the wall portion 11g. As shown in FIG. 3, the compression spring 15 is accommodated over a range near the entire circumference along the counterclockwise direction shown in the figure from the wall portion 11g. The other end of the compression spring 15 is in contact with a moving wall portion 13a provided on the operation plate 13 and entering the spring accommodating portion 11c.
As shown in FIG. 4, when the operation plate 13 is rotated in the screw loosening direction, the moving wall portion 13a is displaced to the left in the drawing, and the compression spring 15 is thereby contracted (compressed). Therefore, the operation plate 13 is urged in the screw tightening direction with respect to the nut body 11, and the rotation operation of the operation plate 13 in the screw loosening direction is performed against the compression spring 15.
Further, the operation plate 13 is urged in the screw tightening direction by the compression spring 15, so that the movable wall portion 13 a is returned to the initial position where it abuts on the cylindrical wall portion 11 h provided on the nut body 11. In the state where the operation plate 13 is returned to the initial position, the relative rotation in the screw tightening direction of the operation plate 13 with respect to the nut main body 11 is restricted, and accordingly, the nut main body 11 is integrated with the rotation operation of the operation plate 13 in the screw tightening direction. Rotates in the screwing direction.
Next, the piston 17 is accommodated in the cylinder part 11d so that an axial displacement is possible. An insertion hole 11e is formed in the bottom portion (upper portion in FIG. 2) of the cylinder portion 11d. The distal end side (upper end side in FIG. 2) of the piston 17 protrudes into the pressure chamber 14 through the insertion hole 11e. A seal ring 22 is attached to the piston 17. The seal ring 22 provides a fluid-tight seal between the cylinder portion 11d and the piston 17, and as a result, the pressure chamber 14 is liquid-tightly sealed from the opening side of the cylinder portion 11d (below the seal ring 22 in FIG. 2). ing.

A flange portion 17 a is provided at the rear end portion (lower end portion in FIG. 2) of the piston 17. Opposite to the flange portion 17a, a cam portion 13b is formed on the inner surface of the operation plate 13 so as to rise to the piston 17 side. As shown in FIG. 4, the cam portion 13b is formed in a certain range in the circumferential direction from the moving wall portion 13a, and is highest in the moving wall portion 13a side and gradually decreases toward the right side in FIG. Inclined. Therefore, when the operation plate 13 is rotated in the tightening direction with respect to the nut body 11 by the compression spring 15 and the moving wall portion 13a is in contact with the cylinder portion 11d, the flange portion 17a of the piston 17 is the cam portion 13b. It touches the highest part of When the operation plate 13 is rotated in the loosening direction against the compression spring 15 from this state (displaced to the left in FIG. 4), the piston 17 moves relatively to a lower portion of the cam portion 13b.
As described above, the front end side of the piston 17 enters the pressure chamber 14. For this reason, the piston 17 receives the pressure inside the pressure chamber 14 at its tip end surface, so that the piston 17 always cams out the direction from the cylinder portion 11d (downward in FIGS. 2 and 4, hereinafter referred to as the unlocking direction), that is, the flange portion 17a. It is biased in the direction of pressing against the portion 13b.
Therefore, as shown in FIG. 5, when the operating plate 13 is rotated in the screw loosening direction against the compression spring 15, the piston 17 is moved in the unlocking direction by its urging force, whereby the tip of the piston 17 is moved. Moves in the direction of retreating from the pressure chamber 14. On the other hand, as shown in FIGS. 2 and 4, the operation plate 13 is returned to the screw tightening direction by the compression spring 15 at the initial position. In this initial position, the flange portion 17a of the piston 17 relatively moves to the highest portion of the cam portion, whereby the piston 17 protrudes its tip into the pressure chamber 14 against the urging force (hereinafter referred to as a lock). Move in the direction).
When the piston 17 moves in the locking direction and its tip protrudes into the pressure chamber 14, the pressure in the pressure chamber 14 rises, and as a result, the pressing plate 12 is displaced away from the nut body 11. On the other hand, when the piston 17 moves in the unlocking direction and its tip end is displaced in the direction of retreating from the pressure chamber 14, the volume of the pressure chamber 14 is slightly increased. The pressing force on the grinding wheel 2 is reduced.

According to the fixing nut 10 of the present embodiment configured as described above, the operating plate 13 is screwed by the compression spring 15 in the screw tightening direction as shown in FIGS. The moving wall portion 13a is in contact with the cylinder portion 11d. In this state, the flange portion 17a of the piston 17 is brought into contact with the highest portion of the cam portion 13b, and the piston 17 is moved in the locking direction. Therefore, the tip portion of the piston 17 protrudes into the pressure chamber 14 and is pressed. 12 is in a state of being displaced in a direction slightly away from the nut body 11.
The fixing nut 10 in the non-tightened state is fastened to the male thread portion 3b of the spindle 3 so that the pressing plate 12 is brought into contact with the grinding wheel 2 and further tightened in this contact state, whereby the grinding wheel 2 is attached to the spindle 3. It is attached. In order to tighten the fixing nut 10, when the user rotates the operation plate 13 in the screwing direction, the moving wall portion 13 a of the operation plate 13 is brought into contact with the cylinder portion 11 d of the nut body 11, thereby 13 and the nut body 11 are integrally rotated in the screw tightening direction.

By using the grinder 1, grinding resistance or inertia at the time of starting is added to the fixing nut 10 as an external force in the tightening direction, and thereby the fixing nut 10 is tightened with a force larger than the tightening force by the user. Go. When the fixing nut 10 is tightened with a greater force against the male screw portion 3b, the pressing plate 12 is pressed against the grinding wheel 2 with a greater force.
However, when the fixing nut 10 is loosened with respect to the screw shaft 3 b in order to replace the grinding wheel 2, the operation plate 13 is rotated relative to the nut body 11 in the screw loosening direction against the compression spring 15. Then, as a result of the piston 17 moving in the unlocking direction and the pressure in the pressure chamber 14 decreasing, the pressing force of the pressing plate 12 against the grinding wheel 2 decreases. For this reason, if the user applies a force necessary to rotate the operation plate 13 against the compression spring 15 in the screw loosening direction, the pressing force of the pressing plate 12 against the grinding wheel 2 is reduced, and thus the subsequent small amount. The fixing nut 10 can be loosened by force.
As described above, when loosening the fixing nut 10, the user only has to rotate the operation plate 13 in the screw loosening direction and rotate it in the same direction. There is no need to perform the troublesome operation of rotating the nut main body 33 with the other hand while pushing in, and it can be easily loosened with one hand.

The embodiment described above can be implemented with various modifications. For example, the cylinder part 11d and the piston 17 are arranged at one place on the nut body 11, and the cam part 13b is provided at one place on the operation plate 13 corresponding to this. It is good also as a structure which provides multiple places in a main body and provides a cam part in multiple places of an operation board corresponding to this.
Furthermore, although the fixing nut for fixing the grinding wheel 2 as the processing tool of the disc grinder 1 has been illustrated, the fixing nut for fixing the same circular processing tool in the disc sander or the circular saw blade in the circular saw machine It can also be applied to a fixing nut or the like for fixing to the spindle.
In addition, the fixing nut according to the present invention is not limited to fixing a processing tool in an electric power tool, but is a fastener combined with a normal fastening bolt (male screw), or an anchor bolt when installing various mechanical equipment. It is a fixing nut etc. used in combination, and can be widely applied to a fixing nut for fixing various articles to a male screw part.

It is a figure which shows the state which fixed the grinding stone to the spindle with the fixing nut which concerns on embodiment of this invention, Comprising: It is a longitudinal cross-sectional view of a fixing nut periphery. It is a longitudinal cross-sectional view of the fixing nut of this embodiment. FIG. 3 is a cross-sectional view taken along line (3)-(3) in FIG. 1 and is a cross-sectional view of the fixing nut. FIG. 4 is a sectional view taken along line (4)-(4) in FIG. 3 and is a longitudinal sectional view around a cylinder portion of a fixing nut. This figure shows the non-operating state of the operation plate in which the tip of the piston protrudes into the pressure chamber. FIG. 4 is a sectional view taken along line (4)-(4) in FIG. 3 and is a longitudinal sectional view around a cylinder portion of a fixing nut. This figure shows a state in which the operating plate is rotated in the screw loosening direction and the piston is moved in a direction in which its tip is retracted from the pressure chamber. It is a figure which shows the conventional fixing nut. This figure is the figure which used FIG. 1 of the international publication 01/10600 pamphlet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Disc grinder 2 ... Grinding grindstone (processing tool), 2a ... Mounting hole 3 ... Spindle, 3a ... Flange part, 3b ... Male thread part 4 ... Inner flange 10 ... Fixed nut 11 ... Nut main body, 11a ... Boss part, 11b ... Female thread portion 11c ... Spring accommodating portion, 11ca, 11cb ... Wall portion 11d ... Cylinder portion, 11e ... Insertion hole, 11f ... Outer peripheral wall portion, 11g ... Wall portion 12 ... Press plate 13 ... Operation plate, 13a ... Moving wall portion, 13b DESCRIPTION OF SYMBOLS ... Cam part 14 ... Pressure chamber 15 ... Compression spring 16 ... Retaining ring 17 ... Piston, 17a ... Flange part 18 ... Retaining ring 20-24 ... Seal ring 30 ... Conventional fixing nut 31 ... Grinding wheel 32 ... Spindle, 32a ... Flange Portion 33 ... Nut body 34 ... Pressure chamber 35 ... Pressing plate 36 ... Push button 37 ... Piston plate 37a ... Shallow engagement recess 37b ... Deep engagement recess 39 ... Steel 40 ... compression spring

Claims (2)

A fixing nut that is fastened to a male screw part and sandwiches and fixes an article between the male screw part and the flange part,
A nut main body having a female screw portion to which the male screw portion is fastened; a pressing plate provided on one side of the nut main body so as to be displaceable in the screw axis direction and pressed against the article; and the pressing plate and the nut main body. A pressure chamber provided in between and containing a pressure medium; a piston provided in the nut body so as to be displaceable in a screw axis direction; and a tip end portion entering the pressure chamber; and the other surface side of the nut body. An operation plate provided in a relatively rotatable manner, and a cam portion provided on the operation plate facing the rear end of the piston,
By rotating the operation plate in the screw loosening direction, the abutting position with respect to the cam portion is displaced at the rear end portion of the piston, the piston is retracted, and the pressure chamber pressure decreases due to the piston retracting, A fixing nut configured to reduce a pressing force of the pressing plate against the article. A fixing nut that is fastened to a male screw portion of a spindle and sandwiches and fixes a processing tool between the flange portion of the spindle,
A nut main body having a female screw portion to which the male screw portion is fastened; a pressing plate provided on one side of the nut main body so as to be displaceable in the screw axis direction and pressed against the processing tool; the pressing plate and the nut main body; A pressure chamber in which a pressure medium is enclosed, a piston that is displaceable in the screw shaft direction in the nut body, and a tip portion of which enters the pressure chamber, and the other surface side of the nut body An operation plate provided in a relatively rotatable manner, and a cam portion provided on the operation plate facing the rear end of the piston,
By rotating the operation plate in the screw loosening direction, the abutting position with respect to the cam portion is displaced at the rear end portion of the piston, the piston is retracted, and the pressure chamber pressure decreases due to the piston retracting, A fixing nut configured to reduce the pressing force of the pressing plate against the processing tool.

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