JP4567225B2 - Air motor for air tools - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an air motor used for an air tool, and more particularly, to an air motor for an air tool that can rotate a rotor at a high rotational speed such that the rotor rotates several tens of thousands in one minute by compressed air with an increased ejection speed. Is.
[0002]
[Prior art]
An air motor used for an air tool normally has a rotor having a plurality of axial blades arranged rotatably in a cylinder, and generates compressed torque by blowing compressed air onto the rotor blades. I am letting.
In this air motor, the rotor can be rotated with a relatively large torque by jetting compressed air onto a blade having a large area.
[0003]
[Problems to be solved by the invention]
However, in the above conventional air motor for an air tool, since the compressed air is ejected into a relatively wide space of the rotor blades, the rotational speed is limited, and the rotational speed is high such that tens of thousands of revolutions per minute. Could not be used.
[0004]
In view of the above-described problems of the conventional air tool air motor, the present invention can rotate the rotor at a high rotational speed such that the rotor rotates several tens of thousands of minutes with the compressed air whose jet speed is increased. An object is to provide an air motor.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an air motor for an air tool according to the present invention has a disk-like rotor provided with a rotor shaft rotatably disposed in a cylinder, and the rotor is provided with an air introduction having an opening at an end surface of the rotor. A plurality of holes and a plurality of ejection holes that communicate with the outer peripheral surface of the rotor from the air introduction holes to eject air to the rotation rear are formed in the circumferential direction, and an opening of the air introduction hole of the rotor is formed on the upper lid of the cylinder. Provided with a plurality of air supply holes provided at opposite positions, and provided with a concavo-convex portion provided at a position opposite to the ejection holes of the rotor on the peripheral wall, and a plurality of exhaust holes formed on both sides of the concavo-convex portion. And a space formed on both sides of the concavo-convex portion and an annular exhaust passage formed on the outer periphery of the peripheral wall of the cylinder are communicated with each other through the exhaust hole .
[0006]
This air motor for an air tool generates rotational torque in the rotor by jetting air from the plurality of jet holes on the outer peripheral surface of the rotor to the concave and convex portions of the cylinder, so that the flow passage cross-sectional area of the jet holes is reduced. The compressed air whose jetting speed is increased can be applied to the concave and convex portions of the cylinder to obtain a strong reaction force, whereby the rotor can be rotated at such a high rotational speed as to make tens of thousands of revolutions per minute.
[0007]
In this case, a forward / reverse rotation switching valve is provided, and the air introduction hole formed in the switching valve is selectively matched with the forward rotation air supply hole and the reverse rotation air supply hole formed in the cylinder, so that the air is supplied. It can be made to eject from either one of the forward rotation ejection hole or the reverse rotation ejection hole .
[0008]
Thus, the forward and reverse rotatable can be Rukoto.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an air motor for an air tool of the present invention will be described below with reference to the drawings.
[0010]
1 to 2 show an embodiment of an air motor for an air tool of the present invention.
In this air motor 1 for an air tool, a disk-shaped rotor 2 having a rotor shaft 2 a is rotatably disposed in a cylinder 3.
The rotor 2 has a bottomed air introduction hole 4 having an opening on the upper end surface of the rotor 2, and an ejection hole through which air is communicated from the air introduction hole 4 to the outer peripheral surface of the rotor 2 to rotate backward. 5 are formed at equal intervals in the circumferential direction.
Further, the cylinder 3 has a large number of air supply holes 6 provided around the opening of the air introduction hole 4 of the rotor 2 and a plurality of supply holes 6 provided at a position opposed to the ejection hole 5 of the rotor 2. And a plurality of exhaust holes 8 formed in the vicinity of the uneven portion 7.
[0011]
The rotor 2 is disposed in the cylinder 3 with a rotor shaft 2 a disposed at the center of the short cylindrical body extending vertically through the cylinder 3 and supported by a bearing B.
The air introduction holes 4 are formed so that the openings thereof are concentrically arranged on the upper end surface of the rotor 2, and the ejection holes 5 are opened in the middle in the axial direction of the outer peripheral surface of the rotor 2. Is formed.
[0012]
The cylinder 3 includes a cylinder upper lid 9 that is in sliding contact with the upper end surface of the rotor 2, a main body casing lower lid 10 that is in sliding contact with the lower end surface of the rotor 2, and a short cylindrical peripheral wall that concentrically surrounds the outer peripheral surface of the rotor 2. 11.
The air supply holes 6 arranged concentrically in the cylinder upper cover 9 of the cylinder 3 are formed obliquely so as to incline in the rotation direction of the rotor 2. Further, on the cylinder upper cover 9, a compressor An air supply chamber 12 that squeezes air from the air supply and supplies the air supply holes 6 to each air supply hole 6 is formed by the upper lid 9 and the main body casing 13.
The peripheral wall 11 of the cylinder 3 is provided with an uneven portion 7 in the middle in the axial direction, and the same number of exhaust holes 8 are formed on both sides of the uneven portion 7 at the same interval as the ejection holes 5 of the rotor 2. Has been. The concavo-convex portion 7 is disposed in the vicinity of the rotor 2 such that the tip of the convex portion 7a is in sliding contact with the rotor 2 and closes the opening of the ejection hole 5 according to the rotation angle.
An annular exhaust passage 14 is formed on the outer periphery of the cylinder peripheral wall 11, and air from the exhaust hole 8 is discharged to the outside through the exhaust passage 14.
[0013]
In this case, in the air motor 1 for an air tool of the present embodiment, the angle of the ejection hole 5 of the rotor 2 is a tangential direction. For example, as shown in FIG. Can be selected.
In addition, as for the shape of the uneven portion 7 of the cylinder 3, various shapes can be selected as shown in FIGS. 4 (a) to (d).
[0014]
Next, the example which used the air motor 1 for air tools of a present Example for the grinder at FIGS. 5-6 is shown.
The air motor 1 for an air tool is disposed at the upper part of the grinder 15, and a pinion 16 formed at the tip of the rotor shaft 2 a meshes with a gear 19 of a reduction mechanism 18 that rotates the spindle 17 of the grinder 15.
The grinder 15 pulls the trigger 20 to open the valve 21 and introduces air from the compressor into the air motor 1, so that the rotational force of the rotor shaft 2 a is increased with the torque increased via the speed reduction mechanism 18. This spindle 17 can be rotated.
[0015]
Thus, in the air motor 1 for an air tool of the present embodiment, air is ejected from the large number of ejection holes 5 on the outer peripheral surface of the rotor to the concavo-convex portion 7 of the cylinder 3 as shown in FIGS. 3 (a) to 3 (f). As a result, a rotational torque is generated in the rotor 2, so that compressed air whose flow passage cross-sectional area of the ejection hole 5 is reduced and the ejection speed is increased is applied to the uneven portion 7 of the cylinder 3 to obtain a strong reaction force. Thus, the rotor 2 can be rotated at a high rotational speed such that the rotor 2 rotates several tens of thousands in one minute.
Actually, when a conventional rotary air motor having a rotor diameter of 58 mm was compared with the turbine air motor 1 of the present embodiment, in the conventional example, the maximum rotational speed was 8890 rpm, and the maximum wind speed from the ejection hole was 27 m / On the other hand, in the air tool air motor 1 of this example, the maximum rotation speed was 50000 rpm, and the maximum wind speed from the ejection hole 5 was 152 m / second.
Further, since the air supply hole 6 of the cylinder 3 is formed obliquely so as to incline in the rotation direction of the rotor 2, air is ejected from the air supply hole 6 in the rotation direction of the rotor 2 to start the air motor 1 for the air tool. And the rotation speed could be improved.
[0016]
As mentioned above, although the air motor for air tools of this invention was demonstrated based on the Example, this invention is not limited to the structure described in the said Example, For example, the deformation | transformation implementation shown to FIGS. As shown in the example, a forward / reverse switching valve 22 is provided, and the switching valve 22 is switched (in this embodiment, the switching valve 22 is rotated by a predetermined angle), thereby introducing the air formed in the switching valve 22. The holes 22a, 22b and a number of the positive rotation air supply holes 6a and the reverse rotation air supply holes 6b provided around the cylinder 3 are selectively matched to each other so that the compressed air can be used for the normal rotation. It is ejected from either the forward rotation jet hole 5a or the reverse rotation jet hole 5b via the air introduction hole 4a or the reverse rotation air introduction hole 4b (in this embodiment, forward rotation Jet hole 5a and reverse jet 5b is formed in the same plane, but the formation positions of the forward rotation ejection holes 5a and the reverse rotation ejection holes 5b can also be made different in the height direction (FIG. 7). It is possible to prevent the forward rotation ejection hole 5a and the reverse rotation ejection hole 5b from coming into contact with each other, and to form both of them close to each other. The configuration of the rotor 2 can be changed as appropriate without departing from the spirit of the rotor 2 such that the rotor 2 can be rotated in both forward and reverse directions.
[0017]
【The invention's effect】
According to the air motor for an air tool of the present invention, the rotational torque is generated in the rotor by ejecting air backward from the plurality of ejection holes on the outer peripheral surface of the rotor to the uneven portion of the cylinder. Compressed air with a reduced area and increased ejection speed can be applied to the concave and convex portions of the cylinder to obtain a strong reaction force, thereby rotating the rotor at a high rotational speed such that the rotor rotates tens of thousands of minutes. be able to.
[0018]
In addition, a forward / reverse rotation switching valve is provided, and the air introduction hole formed in the switching valve is selectively matched with the forward rotation air supply hole and the reverse rotation air supply hole formed in the cylinder to forwardly rotate the air. by so jetted from one of ejection holes or ejection hole of the reverse rotation of the use, the forward and reverse rotatable can be Rukoto.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an embodiment of an air motor for an air tool of the present invention.
FIG. 2 is a cross-sectional plan view of the same part.
FIG. 3 is an explanatory diagram showing a relationship between a jet hole formed by rotation of a rotor and an uneven portion of a cylinder.
FIG. 4 is a cross-sectional view showing an example of an uneven portion.
FIG. 5 is a longitudinal sectional view showing an example in which the air motor for an air tool of the embodiment is used in a grinder.
FIG. 6 is a sectional plan view of the same part.
FIG. 7 is a longitudinal sectional view showing a modified embodiment of the air motor for an air tool of the present invention.
FIG. 8 is an explanatory diagram showing the relationship between the ejection hole and the concavo-convex portion of the cylinder.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air motor for air tools 2 Rotor 2a Rotor shaft 3 Cylinder 4, 4a, 4b Air introduction hole 5, 5a, 5b Ejection hole 6, 6a, 6b Air supply hole 7 Concavity and convexity part 8 Exhaust hole 9 Cylinder upper cover 10 Main body casing lower cover 11 Circumferential wall DESCRIPTION OF SYMBOLS 12 Air supply chamber 13 Main body casing 14 Exhaust flow path 15 Grinder 16 Pinion 17 Spindle 18 Reduction mechanism 19 Gear 20 Trigger 21 Valve 22 Switching valve 22a, 22b Air introduction hole B Bearing

Claims (2)

A disk-shaped rotor having a rotor shaft is rotatably disposed in the cylinder, and the rotor has an air introduction hole having an opening at an end surface of the rotor, and communicates from the air introduction hole to the outer peripheral surface of the rotor. together form a plurality of the ejection holes for ejecting air to the rotating backwards in the circumferential direction, the upper cover of the cylinder, a plurality of supply holes provided around a position facing the opening of the air inlet holes of the rotor, the peripheral wall in a concavo-convex portion provided around a position ejection hole facing the rotor, and a plurality of exhaust holes formed on both sides of the uneven portion is provided, via the exhaust pores, are formed on both sides of the concave-convex portion An air motor for an air tool, wherein the space is communicated with an annular exhaust passage formed on the outer periphery of the peripheral wall of the cylinder . A forward / reverse rotation switching valve is provided, and the air introduction hole formed in the switching valve is selectively matched with the forward rotation air supply hole and the reverse rotation air supply hole formed in the cylinder, so that the air can be used for forward rotation. 2. An air motor for an air tool according to claim 1, wherein the air motor is ejected from either one of the ejection holes or the reverse rotation ejection holes .

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