Air tool and method for using air tool

Abstract

To provide an air tool that can cool a wide area using an exhaust gas.SOLUTION: An air tool includes: an air motor 2; a tip tool 3 rotated by the air motor 2; an exhaust hole 5c for discharging an exhaust gas of the air motor 2 into the outside air; and a guide 6 for guiding the discharged exhaust gas to the tip tool 3. The guide 6 includes: an intake port 6a for taking an exhaust gas into the guide 6; a discharge port 6b for causing the exhaust gas to abut on the tip tool 3; and a lateral opening 6c communicated to the outside air.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an air tool that uses exhaust air from an air motor to cool a tool bit. [Background technology]

[0002] Patent Document 1 describes a pneumatic tool that has an inlet for introducing compressed air and an outlet for discharging the air, and that uses the compressed air introduced through the inlet to rotate a tool such as a tap.The tool is cooled by exhaust air by providing a pipe with one end attached to the outlet and the other end opening toward the tool. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 1-103274 Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the other end (the open end) of the pipe is extended to the vicinity of the tool, which tends to result in localized cooling.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an air tool capable of cooling a wide area by utilizing the exhaust air of an air motor. [Means for solving the problem]

[0006] The air tool of the present invention comprises an air motor 2, a tool tip 3 rotated by the air motor 2, an exhaust hole 5c for blowing exhaust air from the air motor 2 into the outside air, and a guide 6 for directing the blown-out exhaust air to the tool tip 3, and is characterized in that the guide 6 has an inlet 6a for taking in the exhaust air into the guide 6, an outlet 6b for directing the exhaust air at the tool tip 3, as well as a side opening 6c communicating with the outside air.

[0007] In the above air tool, the guide 6 preferably has a bottom 61 extending from the exhaust hole 5c toward the tool tip 3 and two standing walls 62 rising from the bottom 61, and a lateral opening 6c is provided on the surface opposite the bottom 61.

[0008] In addition, it is preferable that the rotation axis S3 of the tip tool 3 is approximately perpendicular to the exhaust blowing direction, and that the imaginary line L6 extending from the bottom 61 toward the tip tool 3 passes between the rotation center O3 of the tip tool 3 and the contact point C3 that contacts the workpiece W.

[0009] In addition, the bottom portion 61 preferably has an inclined surface 61 b ​​for directing the exhaust gas toward the tool bit 3 .

[0010] It is also preferable that the direction of the exhaust hole 5c be changeable.

[0011] A method of using the air tool of the present invention is characterized in that the air tool 1 is used with the tip of the standing wall 62 facing the workpiece W. Effect of the Invention

[0012] In the air tool of the present invention, the exhaust air of the air motor blown out from the exhaust hole is guided to the tip tool by a guide having a side opening that communicates with the outside air, so that the exhaust air reaches the tip tool while drawing in outside air, making it possible to cool a wider area than when the exhaust air is blown out near the tip tool.

[0013] If the guide has a bottom extending from the exhaust hole toward the bit and two upright walls rising from the bottom, and a side opening is provided on the surface opposite the bottom, it is easy for outside air to be drawn in.

[0014] When the rotation axis of the tool tip is approximately perpendicular to the exhaust blowing direction, and an imaginary line extending from the bottom toward the tool tip passes between the rotation center of the tool tip and the contact point with the workpiece, the tool tip heated by cutting heat, etc., can be efficiently cooled.

[0015] Even when the bottom portion has an inclined surface for directing the exhaust gas toward the tool bit, the tool bit can be cooled efficiently.

[0016] If the exhaust holes are redirected, they can easily be switched between cooling and non-cooling as required.

[0017] In the method of using the air tool of the present invention, the workpiece blocks the side opening to a moderate extent, so that the tool bit can be reliably cooled even though the exhaust air is blown out at a distant position. [Brief description of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of an air tool according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged view of the vicinity of the tip portion of FIG. [Diagram 3] FIG. 3A is a perspective view looking down on the air tool, and FIG. 3B is an upside-down perspective view of FIG. 3A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Next, an embodiment of the air tool of the present invention will be described in detail with reference to the drawings. As shown in Fig. 1, the air tool 1 of the present invention includes an air motor 2, a tool tip 3 rotated by the air motor 2, a casing 4 that houses the air motor 2, an exhaust hole 5c that blows out exhaust gas from the air motor 2 to the outside air, and a guide 6 that guides the blown out exhaust gas to the tool tip 3. Each component will be described below.

[0020] The air motor 2 includes a cylinder 21 and a rotor 22 arranged in the cylinder 21. The rotor 22 has a plurality of blades 22a for receiving compressed air supplied into the cylinder 21. The rotor 22 is rotatably supported by a pair of front and rear bearings 7 attached to the casing 4. In this air motor 2, the rotor 22 is rotationally driven by compressed air being supplied into the cylinder 21. The compressed air is supplied from an air hose (not shown) connected to the rear end 4a of the casing 4. Supply and non-supply are switched by operating a lever 8.

[0021] The rotational force generated by the air motor 2 is transmitted to the tool bit 3 via a transmission unit 9 that is generally U-shaped in plan view and protrudes laterally and forward from the casing 4 (see FIG. 3A). The transmission unit 9 supports the tool bit 3 located at the tip side of the casing 4. In plan view, the rotation axis S3 of the tool bit 3 is generally perpendicular to the rotation axis S2 of the air motor 2. The transmission unit 9 is composed of, for example, three shafts with bevel gears meshed with each other. However, it may be composed of two shafts and a belt connecting them to each other, and various configurations may be adopted as long as they are capable of transmitting the rotational force.

[0022] As shown in FIG. 2, the tool tip 3 is located below the rotation axis S2 of the air motor 2 in side view (viewed from the direction of the rotation axis S3 of the tool tip 3). The tool tip 3 is used to process a workpiece W such as a steel plate or an aluminum plate by cutting, grinding, polishing, etc., and is, for example, a carbide bar (carbide rotary bar) mainly composed of tungsten carbide. The tip side is a substantially cylindrical cutter section (processing section) 3a, and the base end side is a shank section 3b connected to the transmission section 9 (see FIG. 3B). The cutter section 3a is located on an extension of the rotation axis S2 of the air motor 2 in plan view. The tool tip 3 is rotated in a direction that causes chips to fly forward (clockwise in FIG. 2). However, it may be rotated in the opposite direction. The tool tip 3 is not limited to a carbide bar, and may be a grindstone, a blade, a file, a brush, or various abrasives. Also, as shown in FIG. 3A, for example, a guard 31 for preventing excessive machining and a protective plate 32 for preventing chips from scattering toward the user are provided around the tip tool 3, but these are not necessarily required.

[0023] The casing 4 is generally cylindrical and houses the air motor 2 therein. A through hole 4b is provided on the underside of the casing 4, which communicates with the inside of the cylinder 21 of the air motor 2 and allows the compressed air in the cylinder 21 to pass through. This through hole 4b is located on the outer periphery of the cylinder 21 of the air motor 2. In addition, it is covered from the outside by a cup member 5.

[0024] The cup member 5 has a top surface 5a facing the through hole 4b and a substantially cylindrical side wall 5b extending from the outer edge of the top surface. Inside the cup member 5, there are housed a breathable sound deadening material 51 and a spring 52 for biasing the sound deadening material 51 toward the through hole 4b. A hole is provided in the side wall 5b of the cup member 5. This hole serves as an exhaust hole 5c for blowing the exhaust air of the air motor 2 to the outside air (see the solid arrow in FIG. 2). The exhaust hole 5c is also provided on the outer periphery of the cylinder 21 of the air motor 2, in other words, at a position overlapping with the cylinder 21 of the air motor 2 in the direction of the rotation axis S2 of the air motor 2. In addition, in a plan view, the exhaust hole 5c is located on an extension of the rotation axis S2 of the air motor 2. The cup member 5 is rotatably attached to the casing 4, and by rotating the cup member 5 around its own central axis, the orientation of the exhaust hole 5c can be changed, in other words, the exhaust blowing direction can be changed (see the solid arrow in Figure 3B).

[0025] The guide 6 is substantially trough-shaped and includes a bottom 61 extending from the exhaust hole 5c toward the tool tip 3, and two standing walls 62 rising from the bottom 61 from the exhaust hole 5c to the tool tip 3. The exhaust hole 5c side of the guide 6 is an inlet 6a for taking in exhaust air, and the tool tip 3 side is an outlet 6b for blowing exhaust air onto the tool tip 3. The portion surrounded by the bottom 61 and the two standing walls 62 is an exhaust flow path 63 for flowing exhaust air. A side opening 6c communicating with the outside air is provided on the surface facing the bottom 61. The side opening 6c is provided over the entire length of the guide 6, but is not necessarily required to be provided over the entire length.

[0026] In side view, the exhaust hole 5c side of the bottom 61 is a flat surface 61a that is approximately parallel to the exhaust air blowing direction, while the tool tip 3 side is an inclined surface 61b to direct the exhaust air flow direction toward the tool tip 3. Specifically, it is inclined downward. An imaginary line L6 extending the inclined surface 61b of the bottom 61 toward the tool tip 3 side passes between the rotation center O3 of the tool tip 3 (the center point of the cutter part) and the contact point (e.g., the lowest point) C3 that contacts the workpiece W.

[0027] The tip (lower end) of the standing wall 62 is located below the exhaust hole 5c. Therefore, the exhaust air blown out passes between the two standing walls 62. The standing walls 62 protrude beyond the bottom 61 over their entire length. Therefore, a gutter-shaped exhaust flow path 63 is formed over the entire length of the bottom 61. The depth of the exhaust flow path 63 becomes shallower toward the tool tip 3 due to the inclined surface 61b. In a plan view, the bottom 61 and the two standing walls 62 are each approximately parallel to the rotation axis S2 of the air motor 2.

[0028] Next, a method of using the air tool 1 configured as above will be described. By tilting the lever 8 towards the casing 4, compressed air is supplied to the air tool 1 from the air hose. This rotates the rotor 22 of the air motor 2, which in turn rotates the tip tool 3. By bringing the tip tool 3 into contact with the workpiece W while pointing the tip of the standing wall 62 towards the workpiece W, processing such as cutting the workpiece W is performed.

[0029] The compressed air supplied to the air motor 2 rotates the rotor 22, then flows into the cup member 5 through the through hole 4b, and is blown forward into the outside air from the exhaust hole 5c of the cup member 5. The blown exhaust air passes through the exhaust passage 63 in the guide 6 toward the tool tip 3, but since the exhaust passage 63 has a side opening 6c, the exhaust air reaches the tool tip 3 while drawing in the surrounding outside air. Therefore, a wider area can be cooled than when exhausting in the vicinity of the tool tip 3. In addition, by using the tool with the tip of the vertical wall 62 facing the workpiece W, the workpiece W moderately blocks the side opening 6c, and the exhaust air can easily reach the tool tip 3 even though it is blown out at a position away from the tool tip 3.

[0030] In addition, when viewed from the direction of the rotation axis S3 of the tool tip 3, the imaginary line L6 extending the inclined surface 61b of the bottom 61 toward the tool tip 3 passes between the center point O3 of the cutter part 3a and the lowest point C3 in contact with the workpiece W, so that the rear side of the cutter part 3a can be mainly cooled. When the tool tip 3 rotates so as to throw chips forward, the rear side of the cutter part 3a is the part immediately before it comes into contact with the workpiece W again after contacting the workpiece W. By cooling this part, it becomes difficult to transmit the heat of the tool tip 3 heated by cutting heat, etc. to the workpiece W, and melting of the workpiece W and adhesion of the melted workpiece W to the tool tip 3 can be suppressed. This is particularly suitable for machining materials with low melting points such as aluminum.

[0031] If cooling is not required or if it is not desired to have chips fly forward, the direction of the exhaust hole 5c can be changed so that exhaust air does not flow into the guide 6. The direction of the exhaust hole 5c can be easily changed by rotating the cup member 5. In short, it is possible to easily switch between cooling and non-cooling.

[0032] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above embodiment, the exhaust hole 5c is provided in the cup member 5, but an approximately L-shaped nozzle may be attached to the through hole 4b, and the opening at the tip of the nozzle may serve as the exhaust hole 5c. If the nozzle itself is flexible, the direction of the exhaust hole 5c can be changed by bending the nozzle. [Explanation of symbols]

[0033] 1 Air Tools 2 Air motor 21 Cylinder 22 Rotor 22a Feather S2 Rotational Axis 3 Tip tool 3a Processing part (cutter part) 3b Shank S3 Rotation Axis O3 Center point (center of rotation) C3 contact point (lowest point) 31 Guard 32 Protective plate 4 Casing 4a Rear end 4b Through hole 5 Cup member 5a Top 5b side wall 5c Exhaust hole 51 Sound deadening material 52 Spring 6 Guide 6a Intake port 6b Outlet 6c Side opening 61 Bottom 61a flat surface 61b Slope 62 Standing Wall 63 Exhaust flow path L6 Virtual Line 7. Bearings 8 Lever 9 Transmission section W Workpiece

Claims

1. An air motor; a tool tip rotated by an air motor; An exhaust hole for blowing the exhaust air of the air motor to the outside air; A guide that guides the blown-out exhaust to the tip tool is provided. The guide has an intake port for taking exhaust air into the guide, an exhaust port for directing the exhaust air to the tool bit, and a side opening communicating with the outside air.

2. 2. The air tool according to claim 1, wherein the guide comprises a bottom portion extending from the exhaust hole toward the tool bit, and two upright walls rising from the bottom portion, and a side opening is provided on a surface opposite the bottom portion.

3. The rotation axis of the tool bit is approximately perpendicular to the exhaust direction.

3. The air tool according to claim 2, wherein an imaginary line extending from the bottom portion toward the tool bit passes between a rotation center of the tool bit and a contact point that contacts the workpiece.

4. 4. The air tool of claim 3, wherein the bottom portion has an inclined surface for directing the exhaust air toward the tool bit.

5. 2. The air tool of claim 1, wherein the exhaust opening is redirectable.

6. A method for using the air tool according to claim 2, wherein the air tool is used with a tip of the upright wall facing the workpiece.

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