JP2001088003A - Pneumatic tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily demount a lock bolt for fixing a cutter for a workpiece that is screwed in a screw hole of a spindle, with one tool. SOLUTION: A grinding wheel A is held between a torque transmitting cylinder 7 at a tip of a spindle rotated by an air motor 2 and a flange 9a of a holding member 9 inserted into a center hole of the grinding wheel A. A lock bolt 11 inserted into a bolt insertion hole of the member 9 is screwed into a screw hole 10 of the spindle 5, and thereby the grinding wheel A is fixed. In a rotor case 1 in which the spindle 5 is built, a guide hole 16 is formed in an coaxial manner therewith, and a push button 18 and a spring member 23 are built in the hole 16 in such a condition that the button 18 is supported so that it can move freely while unable to rotate. A square hole 19 is formed at a lower surface of the button 18 while a square shaft 15 is formed at a rear end of the spindle 5. By pushing the button 18 the square hole 19 is fitted to the square shaft 15 to thereby prevent rotation of the spindle. Mounting/ demounting of the lock bolt 11 is thus facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tool such as a grinder driven by compressed air.

[0002]

2. Description of the Related Art A disc-shaped grindstone is attached to the tip of a spindle rotated by an air motor incorporated in a rotor case, and the grindstone is configured to rotate the grindstone by driving the air motor. There are two types, an angle grinder arranged perpendicular to the rotor of the air motor and a straight grinder arranged coaxially with the rotor of the air motor.

In an angle grinder, a stone flange is connected to a tip of a spindle, and a holding member having a flange for holding a tool is inserted into a center hole of a grinding stone which is axially positioned by abutting against an end face of the stone flange. Penetrates this holding member, screw-engages a headed lock bolt into a screw hole formed in the tip surface of the spindle, and tightens the lock bolt to press the holding member toward the stone flange to fix the grindstone I am trying to do it.

[0004] Here, the holding member is formed into a female screw formed on the inner circumference, and the female screw is formed into a male screw formed on the outer circumference of the tip end of the spindle when the holding member is inserted into the square hole of the stone flange with the outer circumference being square. May be engaged.

On the other hand, in a straight grinder,
A screw shaft is provided at the tip of the spindle, a disc-shaped grindstone is fitted to this screw shaft, abuts against the stone flange attached to the tip of the spindle, and the tightening nut is screwed onto the screw shaft. The grindstone is held between the stone flange and the locknut, which is screw-engaged with the screw shaft, so that the tightening nut is not loosened to hold the grindstone in a fixed state.

[0006]

By the way, in the angle grinder, after removing the lock bolt, the gripping member is removed and the whetstone is replaced.
When the lock bolt is rotated, the spindle rotates together, so that it is necessary to engage a wrench on the stone flange to stop the spindle from rotating, and to engage the lock bolt with a wrench in the locked state to rotate the spindle. in this way,
Since the replacement of the grindstone is a two-handed operation using two tools, there is a problem that it takes time to replace the grindstone.

On the other hand, in a straight grinder,
The wrench is engaged with the stone flange, and the lock nut and tightening nut are rotated while the spindle is not turned.In this case, the work is performed with two hands using two tools. Was time consuming.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lock bolt and a lock nut for fixing a work processing tool so that a spindle on which a work processing tool such as a grinding wheel or the like is mounted can be prevented from rotating without using a tool. An object of the present invention is to provide a pneumatic tool which can be easily attached and detached by one-handed operation using a tool.

[0009]

According to a first aspect of the present invention, a spindle rotated by an air motor incorporated in a rotor case is arranged so as to intersect with a rotor of the air motor. A clamping member having a tool contact portion for positioning a circular workpiece machining tool in the axial direction at the tip of the spindle, and a flange for clamping the tool in a center hole of the workpiece machining tool contacted with the tool contact portion. In the pneumatic tool which penetrates the holding member and fixes the holding member by tightening a lock bolt screwed into the front end surface of the spindle, a square shaft is formed at the rear end of the spindle, and the rotor case is Is provided with a guide hole coaxially with the spindle, and a push button having a square hole engageable with the square shaft is slidably inserted into the guide hole, and is prevented from rotating. A stopper is provided at the opening of the guide hole at a position where the square hole of the push button is disengaged from the square shaft, and the push button is pressed by a spring member in a direction abutting on the stopper. ing.

In the first aspect of the present invention, when the push button is pushed in, the square hole provided below the push button is engaged with the square shaft at the rear end of the spindle to prevent the spindle from rotating. For this reason, a tool is not required for stopping the rotation of the spindle, and the lock bolt can be easily attached and detached with one tool.

In the second invention, a spindle rotated by an air motor incorporated in a rotor case is arranged coaxially with a rotor of the air motor, and a spindle is provided on a screw shaft provided at a tip end of the spindle. In a pneumatic tool in which a fastening nut for fixing a circular workpiece machining tool and a lock nut for locking the fastening nut are screwed, the spindle is covered, and an end is connected to the rotor case. The guide cylinder is provided with an operation cylinder slidable along the outer peripheral surface thereof, a stopper for restricting a slide amount of the operation cylinder, and a spring member for pressing the operation cylinder toward the stopper. Is provided with an engagement pin that is inserted into an axial long hole formed in the guide cylinder,
The spindle has an annular groove into which the tip of the engaging pin is inserted. When the operating cylinder is moved in a direction away from the stopper on one side surface of the annular groove, the engaging pin is fitted. The configuration in which the engaging groove is provided is adopted.

In the second aspect of the invention, when the operating cylinder is moved in a direction away from the stopper, the engaging pin provided on the operating cylinder engages with the engaging groove formed in the spindle, and the spindle is prevented from rotating. Therefore, a tool is not required for stopping the rotation of the spindle, and the lock nut and the tightening nut can be easily attached and detached with one tool.

Further, in the third invention, a spindle rotated by an air motor incorporated in a rotor case is disposed coaxially with a rotor of the air motor, and a screw shaft formed at a tip portion of the spindle has In a pneumatic tool in which a tightening nut for fixing a circular workpiece processing tool and a lock nut for locking the tightening nut are screwed, a guide having an end connected to the rotor case and covering a spindle. A radial pin hole is formed in the cylinder, and an engaging pin and a spring member that presses the engaging pin outward are incorporated into the pin hole, and the spindle has an engaging hole at a position facing the pin hole. A first cylindrical surface for holding the engagement pin in a state of being disengaged from the engagement hole on an inner periphery of an operation cylinder slidably provided along an outer periphery of the guide cylinder, and a first cylinder thereof And a second surface that presses the engagement pin into engagement with the pin hole when the operating cylinder slides, and a second surface that is connected to the tapered surface and holds the engagement pin in engagement with the engagement hole. A configuration having a cylindrical surface is adopted.

In the third aspect of the present invention, when the operating cylinder is slid, the engaging pin is pushed by the tapered surface formed on the inner periphery of the operating cylinder, and the distal end engages with the pin hole. In some cases, the spindle is detented. When the operation cylinder is slid to a position where the second cylindrical surface provided on the inner periphery of the operation cylinder corresponds to the engagement pin, the engagement pin is held in the engagement state, and the spindle is held in the detent state. Is done. For this reason, the lock nut and the tightening nut can be detached while the hand is released from the operation cylinder, and both nuts can be detached more easily.

In the first to third inventions, the work processing tool attached to the tip of the spindle may be a disk-shaped grinding wheel or polishing wheel, or a cutting metal saw. . Alternatively, a polishing brush may be used.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a grinder as a pneumatic tool. An air motor 2 is incorporated in the rotor case 1, and rotation of the rotor 3 in the air motor 2 is transmitted to a spindle 5 via a bevel gear 4 meshing with each other.

The spindle 5 is rotatably supported by a plurality of bearings 6 mounted inside the rotor case 1.

As shown in FIG. 3, a torque transmission cylinder 7 as a tool contact portion is connected to the tip of the spindle 5. The torque transmission cylinder 7 is keyed or spline-fitted to the spindle 5 and is prevented from rotating, so that the torque transmission cylinder 7 rotates integrally with the spindle 5.

The torque transmission cylinder 7 has a flange 7a, and a holding member 9 is inserted into a center hole a of the grinding wheel A in contact with the flange 7a. The holding member 9 is a flange 9 for holding the grinding wheel A with the flange 7 a of the torque transmission cylinder 7.
a. The outer periphery of the holding member 9 is formed in a square shape, and is inserted into a square hole 8 formed in the torque transmission cylinder 7 so as to rotate integrally with the torque transmission cylinder 7.

A screw shaft is formed at the tip of the spindle 5, and a female screw formed on the inner periphery of the holding member is screw-engaged with the screw shaft, so that the flange 7a of the torque transmission cylinder 7 and the flange of the holding member 9 are engaged. The grinding wheel A may be sandwiched between 9a.

A recess 13a and a bolt insertion hole 13b are formed in the holding member 9, and the lock bolt 11 is inserted into the bolt insertion hole 13b. The lock bolt 11 is screw-engaged with a screw hole 10 formed on the tip end surface of the spindle 5, and the clamping member 9 is tightened by the lock bolt 11.
Is pressed toward the torque transmission cylinder 7, and the grinding wheel A is clamped from both sides by the flange 7 a of the torque transmission cylinder 7 and the flange 9 a of the clamping member 9.

It should be noted that a female screw may be formed on the inner periphery of the torque transmission tube 7 and a male screw may be formed on the outer periphery of the holding member 9, and the holding member 9 may be screw-engaged with the torque transmission tube 7.

Here, a wrench engaging hole 14 is provided in the head 12 of the lock bolt 11, and the lock bolt 11 is rotated by a wrench engaged in the wrench engaging hole 14.

As shown in FIGS. 3 and 4, a square shaft 15 is provided at the rear end of the spindle 5. On the other hand, the rotor case 1 has a guide hole 1 coaxially with the spindle 5.
A cylindrical push button 18 is slidably inserted inside a bush 17 incorporated in the guide hole 16.

The bush 17 is omitted and the guide hole 1 is not provided.
The push button 18 may be directly incorporated in the housing 6.

The push button 18 is formed with a square hole 19 which can be engaged with the square shaft 15 provided at the rear end of the spindle 5. The push button 18 is provided with a detent piece 20. The detent piece 20 is slidably inserted into a guide groove 21 formed in the inner periphery of the opening of the guide hole 16, and is provided on both sides of the guide groove 21. The push button 18 is prevented from rotating by the contact of the rotation preventing piece 20.

The amount of outward movement of the push button 18 is limited by a stopper 22 formed of a pin provided in the opening of the guide hole 16. The push button 18 is pressed outward by a spring member 23 incorporated below the push button 18 to be pressed against the stopper 22, and the square hole 19 faces the square shaft 15 in a stopped state in contact with the stopper 22.

Now, when the push button 18 is pushed in and the square hole 19 formed on the lower surface is engaged with the square shaft 15 of the spindle 5, the push button 18 itself is prevented from rotating. become.

For this reason, the push button 18 is held in a pressed state with one hand, and a wrench is engaged with a wrench engaging hole 14 formed in the head 12 of the lock bolt 11 and rotated. Can be removed. When the holding member 9 is screw-engaged with the spindle 5 or the torque transmission cylinder 7, the wrench is engaged with the holding member and rotated, whereby the holding member can be easily removed.

As described above, since the spindle 5 can be prevented from rotating by pushing the push button 18, no tool is required to prevent the rotation of the spindle 5, the mounting and removal of the lock bolt 11 is easy, and the grinding wheel Can be easily replaced.

When the pressing of the push button 18 is released,
When the spring member 23 is pressed, the push button 18 moves outward, the engagement of the square hole 19 with the square shaft 15 of the spindle 5 is released, and the rotation stop of the spindle 5 can be released.

FIGS. 5 to 9 show other examples of the pneumatic tool according to the present invention. In this example, a straight grinder is shown. The straight grinder incorporates an air motor 31 in a rotor case 30 as shown in FIG.
A spindle 33 is arranged coaxially with the rotor 32 of the air motor 31, and the spindle 33 and the rotor 32 are connected by a coupling 34 so that the rotation of the rotor 32 is transmitted to the spindle 33.

At the tip of the spindle 33, a torque transmission cylinder 35 as a positioning member for positioning the grinding wheel A is prevented from rotating around the spindle 33 by a key 29.
A screw shaft 36 is provided at the tip of the spindle 33, and a disk-shaped grinding wheel A and a washer 37 are fitted to the screw shaft 36.

The grinding wheel A is clamped between the washer 37 and the torque transmission cylinder 35 by tightening the tightening nut 38 screwed to the screw shaft 36. In addition, tightening nut 38
Is loosened by tightening a lock nut 39 screw-engaged with the screw shaft 36.

The end of the guide case 40 that covers the spindle 33 is inserted into the end of the rotor case 30. The guide cylinder 40 is fixed to the rotor case 30 by a tightening nut 42 which is screw-engaged with a male screw 41 formed on the outer periphery of the end of the rotor case 30.

As shown in FIGS. 7 (I) and (II), an operation cylinder 43 is slidably fitted outside the guide cylinder 40. The sliding amount of the operating cylinder 43 is limited by a retaining ring 44 as a stopper attached to the outside of the guide cylinder 40, and the operating cylinder 43 is pressed against the retaining ring 44 by a spring member 45 provided outside the guide cylinder 40.

The operating cylinder 43 is provided with an engaging pin 46 projecting in the inner diameter direction. The engagement pin 46 is the guide cylinder 4
It is slidably inserted into an axially long hole 47 formed at 0 and its front end faces the guide cylinder 40.

The spindle 33 has an annular groove 48 into which the tip of the engaging pin 46 is inserted.
8 is an engagement groove 49 into which the engagement pin 46 can be inserted.
Is provided.

When the air motor 31 rotates, the operating cylinder 43 is pressed against the retaining ring 44 by the pressing of the spring member 45, and the tip of the engaging pin 46 is located in the annular groove 48 to hinder the rotation of the spindle 33. It is in a state without things.

When the operating cylinder 43 is turned while being pushed away from the retaining ring 44, the tip of the engaging pin 46 rotates along one side surface of the annular groove 48. When the operating cylinder 43 turns to a position where the tip of the engaging pin 46 faces the opening of the engaging groove 49, the operating cylinder 43 retreats against the elasticity of the spring member 45, and is shown in FIG. Thus, the engagement pin 46 is engaged with the engagement groove 49, and the engagement stops the spindle 33 from rotating.

As described above, since the spindle 33 can be prevented from rotating by retracting the operation cylinder 43 against the elasticity of the spring member 45, the operation nut 43 is held in the retracted state and the lock nut 39 is held. Or tightening nut 3
8 by rotating these nuts 39, 38
Can be attached and detached, and each nut 38, 3
9 can be easily attached and detached with a small force.

As shown in FIGS. 8 (I) and (II), a guide hole 47a extending in the circumferential direction is provided at an end of a long hole 47 formed in the guide cylinder 40, and an engagement formed in the spindle 33. If a lock groove 50 extending in the circumferential direction is formed at the end of the groove 49, the engaging pin 46 is inserted into the engaging groove 49 by retreating the operation cylinder 43, and the engaging pin is inserted into the end face of the engaging groove 49. By rotating the operation cylinder 43 in a state where the contact is made, the engagement pin 46 is engaged with the lock groove 50. The operating cylinder 43 is retracted by this engagement, that is, the spindle 3
3 is kept in a locked state.

Therefore, the lock nut 39 and the tightening nut 38 can be rotated while the hand is released from the operation cylinder 43, and the nuts 38, 39 can be more easily attached and removed. .

FIGS. 9 (I) and (II) show another example of a mechanism for preventing the rotation of the spindle 33 in the straight grinder. In this example, a pin hole 51 penetrating in the radial direction is formed in the guide cylinder 40, and a head 53 is formed in the pin hole 51.
An engagement pin 52 having a spherical surface 53a
2 and a spring member 54 for pressing outwardly.
An engagement hole 55 is formed in the spindle 33 at a position corresponding to the pin hole 51 so that the engagement pin 52 can be engaged.

On the outside of the guide cylinder 40, an operation cylinder 56 whose retreat position is restricted by abutment on the distal end surface of the tightening nut 42 is slidably fitted.
6, a first cylindrical surface 57 for holding the engagement pin 52 out of the engagement hole 55, and a first cylindrical surface 5
7, the head 53 of the engaging pin 52 is pressed when the operating cylinder 56 slides, and the tip end of the engaging pin 52 is
A tapered surface 58 for moving the engagement pin 52 in the radial direction to a position where the engagement pin 52 is engaged, and a second cylindrical surface 59 for holding the engagement pin 52 in an engaged state are formed continuously with the tapered surface 58. The second cylindrical surface 59 is provided with an engaging groove 60 having an arc-shaped cross section with which the head 53 of the engaging pin 52 engages.

Here, the first cylindrical surface 57 is engaged with the engaging pin 5 when the operating cylinder 56 is in contact with the tip of the tightening nut 42.
It corresponds to the second head 53.

FIG. 9 (I) shows that the operating cylinder 56 is
2 shows a state in which it is held at the retracted position by contacting the tip of 2,
The engagement pin 52 is held at a disengagement position where the engagement pin 52 is pressed against the first cylindrical surface 57 of the operation cylinder 56 and comes out of the engagement hole 55.

When the operating cylinder 56 is slid to the left side in the figure from the state shown in FIG. 9 (I), the engaging pin 52 is pushed by the tapered surface 58 and moves inward of the guide cylinder 40, and the tip end is moved. It engages with the engagement hole 55. When the operation cylinder 56 is further slid in the same direction, the engagement pin 52 is held in the engaged state with the second cylindrical surface 59 corresponding to the head 53 of the engagement pin 52.
When the operating cylinder 56 is slid to a position where the engaging groove 60 formed in the second cylindrical surface 59 is opposed to the head 53 of the engaging pin 52, as shown in FIG. Engages with the engagement groove 60, and the operation cylinder 56 is stopped and held by the engagement.
Is held in a state of being engaged with.

As described above, by sliding the operating cylinder 56, the engaging pin 52 can be engaged with the engaging hole 55, and the spindle 33 can be prevented from rotating by the engagement. The removal and attachment of the lock nut 39 or the tightening nut 38 shown in FIG. 1 is easy, and the grinding wheel A can be easily replaced.

In the embodiment, the grinding wheel A is attached to the tip of the spindle 5 or 33. However, the work processing tool attached to the tip of the spindle 5 or 33 is not limited to the grinding wheel. For example, it may be a metal saw,
A disk-shaped brush may be used.

[0051]

As described above, the present invention has the following effects.

According to the first aspect of the present invention, since the spindle can be prevented from rotating by pushing the push button, a tool is not required to prevent the spindle from rotating. The workpiece can be easily attached and detached, and the work processing tool can be easily replaced.

According to the second and third aspects of the present invention, since the spindle can be prevented from rotating by sliding the operation cylinder, no tool is required to prevent the spindle from rotating, and the lock nut and the tightening nut are not required. Can be easily attached and detached with one tool.

According to the third aspect of the present invention,
Since the operating cylinder can be held in a state where the engaging pin is engaged with the engaging hole, the lock nut and the tightening nut can be more easily attached and detached.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a pneumatic tool according to the present invention.

FIG. 2 is a plan view showing a tip portion of the pneumatic tool shown in FIG.

FIG. 3 is an enlarged cross-sectional view showing an installation part of a spindle of the pneumatic tool shown in FIG. 1;

FIG. 4 is an enlarged cross-sectional view showing a rotation stopping mechanism of the spindle shown in FIG. 3;

FIG. 5 is a front view showing another example of the pneumatic tool according to the present invention.

FIG. 6 is an enlarged cross-sectional view showing a tip portion of the pneumatic tool shown in FIG. 5;

7 (I) is a cross-sectional view showing a spindle detent mechanism of the pneumatic tool shown in FIG. 5, and FIG. 7 (II) is a cross-sectional view showing a spindle detent state.

8 (I) is a sectional view showing another example of the rotation preventing mechanism shown in FIG. 7, and FIG. 8 (II) is a sectional view taken along the line II in FIG.

9 (I) is a cross-sectional view showing still another example of the spindle detent mechanism of the pneumatic tool shown in FIG. 5, and (II) is a cross-sectional view showing a detent state of the spindle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotor case 2 Air motor 3 Rotor 5 Spindle 7 Torque transmission cylinder 9 Holding member 11 Lock bolt 15 Square shaft 16 Guide hole 18 Push button 19 Square hole 20 Detent piece 23 Spring member 30 Rotor case 31 Air motor 33 Spindle 36 Screw shaft 38 Tightening Nut 39 Lock nut 40 Guide cylinder 43 Operation cylinder 44 Retaining ring (stopper) 45 Spring member 46 Engagement pin 47 Long hole 48 Annular groove 49 Engagement groove 51 Pin hole 52 Engagement pin 54 Spring member 55 Engagement hole 56 Operation cylinder 57 First cylindrical surface 58 Tapered surface 59 Second cylindrical surface

Claims (3)

[Claims] A spindle rotated by an air motor incorporated in a rotor case is disposed so as to intersect with a rotor of the air motor, and a tool abutment for axially positioning a circular workpiece machining tool at a tip of the spindle. Part was inserted, a clamping member having a flange for tool clamping was inserted into the center hole of the workpiece machining tool contacted with the tool contact portion, penetrated through the clamping member, and screwed into the tip end surface of the spindle. In a pneumatic tool for fixing a holding member by tightening a lock bolt, a square axis is formed at a rear end of the spindle, a guide hole is provided in the rotor case coaxially with the spindle, and the square shaft is provided in the guide hole. Slidably insert a push button having a square hole that can be engaged with, and prevent rotation, at a position where the square hole of the push button is disengaged from the square shaft at the opening of the guide hole. A pneumatic tool comprising: a stopper for preventing a push button from coming off; and the push button is pressed by a spring member in a direction in which the stopper comes into contact with the stopper. 2. A circular workpiece machining tool, wherein a spindle rotated by an air motor incorporated in a rotor case is arranged coaxially with a rotor of the air motor, and a screw shaft provided at a tip end of the spindle is provided with a circular workpiece machining tool. In a pneumatic tool in which a tightening nut for fixing and a lock nut for preventing the tightening nut from loosening are screw-engaged, the guide cylinder which covers the spindle and whose end is connected to the rotor case has an outer periphery. An operating cylinder slidable along a surface, a stopper for limiting a sliding amount of the operating cylinder, and a spring member for pressing the operating cylinder toward the stopper are provided, and the operating cylinder is formed on the guide cylinder. The spindle is provided with an engagement pin that is inserted into the elongated hole in the axial direction, and the spindle is formed with an annular groove into which the tip of the engagement pin is inserted. The pneumatic tool according to claim 1, further comprising an engagement groove into which the engagement pin is fitted when the cylinder is moved in a direction away from the stopper. 3. A spindle rotated by an air motor incorporated in a rotor case is arranged coaxially with a rotor of the air motor, and a screw shaft formed at a tip end of the spindle is provided with a circular workpiece machining tool. In a pneumatic tool in which a fastening nut for fixing and a lock nut for preventing the fastening nut from loosening are screwed, a radial pin hole is formed in a guide cylinder having an end connected to the rotor case and covering the spindle. Forming an engaging pin in the pin hole, a spring member for pressing the engaging pin outward, and the spindle is provided with an engaging hole at a position facing the pin hole,
A first cylindrical surface that holds the engagement pin in a state of being disengaged from the engagement hole on an inner periphery of an operation cylinder slidably provided along an outer periphery of the guide cylinder, and a first cylinder surface that is continuous with the first cylinder surface;
A tapered surface that presses the engagement pin into engagement with the pin hole when the operating cylinder slides, and a second cylindrical surface that is connected to the tapered surface and holds the engagement pin in engagement with the engagement hole. A pneumatic tool characterized by being provided.