JP2005028517A - Air tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tool such as a pneumatic grinder, which reduces the range of a blind corner of the operator with respect to a workpiece during operation thereof, to thereby improve the workability of the pneumatic tool. <P>SOLUTION: According to the structure of the pneumatic tool, an exhaust portion (5) of a pneumatic tool main body is arranged at a rear end of a drive shaft casing (6b) which is protruded from a main body casing (6a) in a direction nearly perpendicular to the same. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air tool such as an air grinder.

  Conventionally, an air tool such as an air grinder has been used as a hand-held tool using an air motor as a drive source.

  For example, the air grinder (40) is composed of an air grinder main body part (41), a polishing part (42), and a handle part (43), as schematically shown in FIGS. 4 (a) and 4 (b). . The air grinder (40) incorporates an air motor, and the rotational force of the air motor driven by the compressed air is transmitted to the polishing section (42), and an abrasive (attached to the tip of the polishing section (42) ( 45) rotates. In this configuration, the operator performs a predetermined polishing operation by grasping the air grinder main body (41) with the right hand and grasping the handle (43) with the left hand.

Since the air grinder (40) uses an air motor as a drive source, it is necessary to provide an exhaust section (46) in order to exhaust the supplied compressed air. Therefore, as shown in FIG. 4 (a), the exhaust part (46) is provided on the side opposite to the attachment position of the grip part (43) of the air grinder main body part (41), and the air grinder (40 ) Is discharged from the exhaust section (46) through a predetermined flow path. The exhaust unit (46) incorporates a silencer (47) as a noise countermeasure against airflow noise of compressed air, driving sound of an air motor, and the like. For this reason, the said exhaust part (46) protrudes from the air grinder main-body part (41) to the side (for example, refer patent document 1).
JP 2001-88056 A

  By the way, when an operator grips and uses an air grinder, the air grinder is often used in a direction substantially orthogonal to the operator's face and body. Therefore, there is a possibility that the exhaust part that protrudes from the side surface of the air grinder main body part enters between the operator's line of sight and the object to be polished, resulting in a blind spot.

  This invention is made | formed in view of this point, The objective is to reduce the blind spot of the operator with respect to a target object at the time of air tool use, and to aim at the improvement of workability | operativity of an air tool.

  According to the present invention, the exhaust part (5) provided in the air tool is disposed at a position where it is difficult to enter the operator's line of sight with respect to the object, thereby reducing the blind spot when working with the air tool and improving the workability of the air tool. It is an improvement.

  Specifically, the invention described in claim 1 includes a main body casing (6a) formed in a substantially cylindrical shape from a front end portion to a rear end portion, and a main body casing (6a) at a front end portion of the main body casing (6a). A casing (6) having a drive shaft casing (6b) protruding in a substantially orthogonal direction, an air motor (7) incorporated in the casing (6), and the drive shaft connected to the air motor (7) It is assumed that the tool is an air tool provided with a tool drive shaft (19) provided in the casing (6b) and an exhaust part (5) for discharging the exhaust of the air motor (7).

  The air tool is characterized in that the exhaust part (5) is provided at a rear end side position in the drive shaft casing (6b).

  In the first aspect of the invention, since the exhaust part (5) is provided at the rear end side position of the drive shaft casing (6b), when the air tool is used, the exhaust part is placed on the line of sight between the operator and the object. (5) is less likely to enter. Therefore, the blind spot when using the air tool can be reduced.

  According to a second aspect of the present invention, in the air tool according to the first aspect, an exhaust hole (27) for discharging the exhaust of the air motor (7) is formed in the exhaust part (5), and the exhaust hole (27) Further, it is characterized in that it is inclined with respect to the central axis of the main casing (6a) on a plane perpendicular to the tool drive shaft (19).

  In the second aspect of the invention, the exhaust hole (27) of the exhaust part (5) is formed so as to be inclined with respect to the central axis of the main casing (6a). The exhaust air is exhausted in an oblique direction so as to avoid the hand of the operator holding the main casing (6a).

  The invention according to claim 3 is the air tool according to claim 1 or 2, wherein the air motor (7) and the tool drive shaft (19) are connected via a bevel gear (12, 22) meshing with each other, The exhaust air of the air motor (7) is configured to flow to the exhaust part (5) through the periphery of the bevel gears (12, 22).

  According to the third aspect of the present invention, the exhaust air discharged from the air motor (7) is transmitted to the meshing portion of the bevel gear (12, 22) for transmitting the rotational force from the air motor (7) to the tool drive shaft (19). Since it flows to the exhaust part (5) through the surroundings, the frictional heat generated at the meshing part of the bevel gears (12, 22) can be absorbed to cool the bevel gears (12, 22).

  In addition, since the exhaust air passage from the air motor (7) to the exhaust part (5) can be lengthened by the above configuration, the air flow noise during driving of the air motor (7) and the bevel gears (12, 22) It is possible to reduce noise caused by the meshing sound.

  According to a fourth aspect of the present invention, in the air tool according to the first, second, or third aspect, a silencer (25) is attached to the exhaust part (5).

  In the invention of claim 4, since the silencer (25) is attached to the exhaust part (5), airflow noise generated when the air motor (7) is driven and the meshing sound of the bevel gear are detected in the exhaust part (5). Can be muted with. At this time, even if the silencer (25) is built in the exhaust part (5), the exhaust part (5) does not block the operator's view.

  As described above, according to the first aspect of the present invention, the exhaust portion (5) is provided at the position on the rear end side of the drive shaft casing (6b) projecting substantially perpendicularly from the front end of the main body casing (6a). Yes. At this position, as described above in the conventional example, the exhaust part (5) is arranged on the front end side surface of the air grinder main body part, so that an operator's blind spot with respect to the object is less likely to occur. Therefore, the workability of the air tool can be improved.

  Further, in this configuration, for example, a handle attachment member can be provided on the side surface at the tip of the main casing (6a). In this case, the operator can attach this grip part (4) to the side opposite to the position where the handle part (4) is normally attached, and depending on the work environment and the object, Can be changed freely. Therefore, the worker can work more flexibly.

  According to the second aspect of the present invention, the exhaust hole (27) of the exhaust part (5) is formed on the plane substantially orthogonal to the tool drive shaft (19) of the drive shaft casing (6b), and the main body casing of the air tool. It is inclined from the central axis of (6a). Therefore, the exhaust air is discharged in a horizontal oblique direction along the exhaust hole (27). For this reason, when using the air tool, the worker can perform a comfortable work without the exhaust air being applied to the hand of the worker.

  According to the invention described in claim 3, the exhaust air of the air motor (7) ventilates the vicinity of the meshing portion of the bevel gears (12, 22) between the air motor (7) and the tool drive shaft (19), It is configured to flow to the exhaust part (5). For this reason, the frictional heat caused by the meshing of the bevel gears (12, 22) can be cooled by the exhaust air.

  Further, with the above configuration, the flow path until the exhaust air is released to the atmosphere is lengthened. Therefore, the flow noise generated by the compressed air and the meshing sound of the bevel gears (12, 22) are interfered by this flow path. . Therefore, noise during driving of the air motor can be reduced.

  According to the fourth aspect of the present invention, the silencer (25) is attached to the exhaust part (5). For this reason, the airflow noise generated from the exhaust part (5) and the meshing sound of the gears are reduced by the noise reduction effect of the silencer (25). For this reason, noise during driving of the air motor (7) can be further reduced. At this time, even if the silencer (25) is incorporated in the exhaust part (5), it does not become a blind spot at the time of work, so that the operator can comfortably use the air grinder (1).

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 of the Invention
1 and 2 are central longitudinal sectional views showing the entire structure of the air grinder, respectively, and II-II in FIG.
FIG.

  The air grinder (1) is generally composed of an air grinder main body (2), a bent end (3), and a handle (4). The casing (6) of the air grinder (1) includes a main body casing (6a) corresponding to the air grinder main body (2), a drive shaft casing (6b) corresponding to the bent end (3), A silencer casing (6c) corresponding to an exhaust section (5) described later is provided.

  The air grinder main body (2) has an air motor (7) built in a substantially cylindrical main body casing (6a). The air motor (7) is configured by disposing a rotor (8) having a plurality of blades in a substantially cylindrical cylinder (39), and the rotor (8) is an air grinder main body (2). The main body casing (6a) is rotatably supported by a pair of bearings (9, 10). A bevel gear (12) for transmitting a rotational force to the bent end (3) is attached to one end (tip) of the output shaft (11) of the rotor (8). On the other hand, in the air grinder main body (2), an air hose attachment part (13) to which an air hose (not shown) is attached is formed at one end (rear end) on the opposite side where the bevel gear (12) is not attached. Yes. The compressed air supplied by the air hose is supplied to the air supply valve (15) that is opened and closed by rotating the air supply handle (14), and the air motor (7 ) Through a speed governor (16) for setting an upper limit value of the rotation speed of the air motor (7). The compressed air causes the rotor (8) disposed in the cylinder (39) of the air motor (7) to rotate.

  On the other hand, as shown in FIG. 1, the cylinder (39) is formed with a plurality of cylinder exhaust holes (17) for discharging exhaust air at the outer periphery thereof. Then, the exhaust air discharged from the cylinder exhaust hole (17) is discharged into the atmosphere from an exhaust part (5) provided in the drive shaft casing (6b) through a flow path described later.

  As shown in FIG. 1, the bent end portion (3) is formed to extend in a substantially orthogonal direction from the tip of the air grinder main body portion (2). The bending end (3) is provided with a tool drive shaft (19) for rotating a disc-shaped abrasive (18) made of a grindstone in the drive shaft casing (6b). This tool drive shaft (19) is disposed so that its drive axis (19a) is orthogonal to the output axis (8a) of the rotor (8), and a pair of bearings ( 20, 21) is rotatably supported. Further, a bevel gear (22) is fixed between the bearings (20, 21) on the tool drive shaft (19), and this bevel gear (22) is connected to the output shaft (11) of the rotor (8). It meshes with a bevel gear (12) attached to the tip. These bevel gears (12, 22) are housed in a bevel gear chamber (23) formed by a main casing (6a).

  With such a configuration, when the air motor (7) is rotated, the rotational force is transmitted from the bevel gear (12) to the bevel gear (22) and the tool drive shaft (19), and finally the abrasive (18) Rotates.

  As shown in FIG. 1, the exhaust part (5) is located at the rear end side position of the drive shaft casing (6b) and is adjacent to the air grinder main body part (2) and the drive shaft casing (6b). Is provided. The exhaust part (5) is provided with a silencer (25), and the exhaust air of the air motor (7) passes through a predetermined flow path, and then passes through the silencer (25) to the exhaust part ( It is discharged into the atmosphere through an exhaust hole (27) formed outside 5).

  The handle (4) is located on the right side of FIG. 2, and from the tip of the air grinder main body (2), the output axis (8a) of the air motor (7) and the drive axis (19a) of the tool drive shaft (19). It is formed to extend in a direction perpendicular to both. However, the attachment position of the handle portion (4) is symmetrical with respect to the drive axis (19a) from the right position in FIG. 2 by providing a handle attachment member (not shown) at the tip of the air motor body (2). It is also possible to change the position to the left side of 2.

  Next, the exhaust structure according to this embodiment will be described in detail.

  As shown in FIG. 1, the cylinder (39) provided in the main body casing (6a) of the air grinder main body (2) has an outer peripheral portion substantially parallel to the output axis (8a) of the rotor (8). A plurality of cylinder exhaust holes (17) arranged side by side are formed. The cylinder exhaust hole (17) is an elongated square hole formed along the outer peripheral portion of the cylinder (39) and extending in a direction perpendicular to the output axis (8a), with the output axis (8a) as the center. Opening in the radial direction.

  In the state where the air motor (7) is housed in the main casing (6a), a substantially cylindrical space is formed between the inner peripheral portion of the main casing (6a) and the outer peripheral portion of the cylinder (39). It is formed and communicates with the cylinder exhaust hole (17). For this reason, this space becomes the first exhaust passage (26) which is a confluence passage of exhaust air discharged from the plurality of cylinder exhaust holes (17). The first exhaust passage (26) is sufficiently large with respect to the cylinder exhaust hole (17), and thus functions as an expansion portion. That is, when exhaust air is introduced into the first exhaust passage (26) from the cylinder exhaust hole (17), the exhaust air rapidly expands, so that a silencing effect due to sound interference can be obtained. The first exhaust passage (26) is formed substantially parallel to the output axis (8a) of the air motor (7) from the base end of the cylinder (39) to the tip of the air grinder main body (2). The gear (12, 22) communicates with the bevel gear chamber (23) in which the gear (12, 22) is housed. Therefore, the exhaust air discharged from the air motor (7) passes through the first exhaust passage (26) and is introduced into the bevel gear chamber (23).

  The bevel gear chamber (23) is provided with bevel gears (12, 22) for transmitting the rotational force generated by the air motor (7) to the bent end (3) as described above. The exhaust air introduced into the bevel gear chamber (23) is used to cool the frictional heat generated by the meshing of the bevel gears (12, 22). The bevel gear chamber (23) communicates with a second exhaust passage (28) provided between the bevel gear chamber (23) and the exhaust portion (5). 28) further communicates with the exhaust section (5). Therefore, the exhaust air that has passed through the bevel gear chamber (23) is introduced into the exhaust section (5) through the second exhaust passage (28).

  3 (a) and 3 (b) are a partial cross-sectional view showing a main structure of the exhaust part (5) and a bb partial cross-sectional view of FIG. 3 (b). As shown in FIGS. 3 (a) and 3 (b), an exhaust space (29) is formed in the silencer casing (6c) in the exhaust part (5). The exhaust space (29) is provided with a silencer (25). The muffler (25) has a muffler cover (30) attached to the exhaust space (29) from an opening on the lower side (lower side of FIG. 3 (a)) provided in the muffler casing (6c). ).

  The silencer (25) has an elliptical or oval silencer (31) as shown in FIG. 3 (b). The silencer (31) is composed of an exhaust valve (32) whose upper side (upper side in FIG. 3a) is opened, and a silencer (33) made of synthetic fiber filled from the opening of the exhaust valve (32). Has been. Further, three exhaust ports (34) are arranged in parallel on the bottom surface of the exhaust valve (32) in a direction substantially orthogonal to both the drive axis (19a) and the output axis (8a). Is formed. A net-like silencer (35) is laid on the bottom surface of the exhaust valve (32). Further, the exhaust valve (32) is formed with two guide holes (36) sandwiched between the three exhaust ports (34). Then, two guide rods (37) corresponding to the guide holes (36) are fitted into the guide holes (36) so as to extend substantially in parallel with the drive axis (19a) of the bent end (3). ing. The upper and lower ends of the guide rod (37) are supported by the upper side surface of the exhaust space (29) and the muffler cover (30), respectively. In this state, the silencer (31) configured by the exhaust valve (32) and the silencer (33) can be moved up and down along the guide (37). . Further, a muffler spring (38) is interposed between the silencer (31) and the muffler cover (30). The muffler (31) is urged toward the upper side by the muffler spring (38) while being fitted into the guide rod (37).

  In the configuration of the silencer (25), in normal times, the exhaust air introduced into the exhaust space (29) passes through the silencer (31) and the exhaust port (34) formed in the exhaust valve (32). ) Is discharged. The silencer (31) reduces noise such as airflow noise accompanying the generation of exhaust air and meshing sound of the bevel gears (12, 22) in the bevel gear chamber (23).

  On the other hand, when the exhaust air adiabatically expands in the exhaust space (29), the moisture in the vicinity of the silencer (33) of the silencer (31) may be cooled and frozen. When the silencer (31) freezes, the exhaust air introduced from the second exhaust passage (28) cannot pass through the silencer (31). For this reason, the exhaust air that has lost its escape area acts against the urging force of the muffler spring (38) to push the muffler (31) downward. In this state, since the silencer (31) is pushed downward along the guide rod (37), a gap is generated between the silencer (31) and the silencer casing (6c). For this reason, the exhaust air is discharged from this gap without passing through the silencer (31).

  Further, as shown in FIG. 3 (b), the exhaust part (5) has a plurality of exhaust holes (communication with the exhaust space (29)) outside the silencer casing (6c) of the exhaust part (5). 27) is formed. The exhaust air silenced by the silencer (31) is finally discharged from the exhaust hole (27). The exhaust hole (27) is inclined with respect to the central axis of the main casing (6a) on a plane perpendicular to the axis of the tool drive shaft (19) provided in the bent end (3). Is formed. In the present embodiment, the exhaust hole (27) is inclined to the left in FIG. 3 (b), and the exhaust air is discharged to the atmosphere obliquely to the left on the plane.

-Effect of the embodiment-
In the present embodiment, the user normally holds the air grinder (1) by holding the main body casing (6a) with the right hand and holding the handle portion (4) with the left hand. Then, the air hose is connected to the air hose mounting portion (13) at the rear end of the air grinder main body (2), and the air supply handle (14) is turned with the right hand to supply air to the air grinder main body (2).

  When air is supplied to the air grinder main body (2), the rotational force generated by the air motor (7) generates the output shaft (11), the bevel gears (12, 22), the tool drive shaft (19), and the abrasive. (18), the user will work on the object to be polished.

  On the other hand, exhaust air discharged from the air motor (7) is discharged from a plurality of cylinder exhaust holes (17) provided in the cylinder (39), passes through a predetermined flow path, and silences the exhaust section (5). After being silenced by (25), it is discharged from the exhaust hole (27) to the atmosphere.

  In such an air grinder (1), in the present embodiment, the exhaust part (5) is provided at the rear end side position of the drive shaft casing (6b). As a result, when the worker holds the main body casing (6a) and performs the work, the exhaust part (5) is difficult to enter between the operator's line of sight with respect to the object to be polished, and a blind spot is unlikely to occur. The exhaust part (5) is disposed adjacent to the main body casing (6a) and the drive shaft casing (6b). When using the air grinder (1), this position is the blind spot of the operator in the first place by the air grinder main body (2), and even if the exhaust part (5) is placed at this position, The blind spot is difficult to increase.

  Moreover, in this structure, the side surface to which the handle portion (4) is not attached at the tip of the air grinder main body portion (2) is in a state where nothing is arranged. In this state, for example, a handle attachment member is provided on the side surface so that the handle portion (4) can be attached, whereby the position of the handle portion (4) can be fixed to the opposite side of the conventional position. Therefore, the operator can freely change the grip of the air grinder main body (2) and the handle (4) according to the object to be polished and the work environment, and can work more flexibly. .

  Further, the exhaust hole (27) is formed so that the wind direction of the exhaust air discharged from the exhaust part (5) is inclined with respect to the operator. Therefore, the exhaust air is not applied to the operator, and more comfortable work can be performed.

  In the present embodiment, the exhaust air discharged from the air motor (7) can be passed through the meshing portion of the bevel gears (12, 22) in the bevel gear chamber (23). For this reason, the frictional heat generated by the meshing of the bevel gears (12, 22) can be cooled.

  Further, since the exhaust air generated from the air motor (7) is released from the exhaust section (25) through the bevel gear chamber (23), the flow path until the exhaust air is released to the atmosphere becomes long. . Therefore, airflow sound generated by compressed air, meshing sound of the bevel gears (12, 22), and the like are interfered by this flow path, and noise generated from the exhaust part (5) when the air motor (7) is driven is reduced.

  Further, since the silencer (25) is provided in the exhaust part, noise during driving of the air motor (7) is further reduced.

<< Other Embodiments >>
This invention is good also as following structures about embodiment of the said air grinder.

  In the present embodiment, a plurality of exhaust holes (27) are provided on the outer surface of the silencer casing (6c) of the exhaust part (5), and the exhaust air is discharged in a direction inclined to the left in FIG. 3 (b). It is formed as follows. However, as shown in FIG. 5, the exhaust part (5) forms an opening on the rear side (lower side of FIG. 5) of the silencer casing (6c), and the exhaust is attachable / detachable to / from the opening. A plate (50) may be installed, and an exhaust hole (27) may be formed in the exhaust plate (50). In this structure, the exhaust plate (50) is turned upside down and attached to the opening of the silencer casing (6c), so that the exhaust air can be discharged to the right oblique direction from the exhaust hole (27). For this reason, for example, when a grip attachment member is provided on the air grinder main body and the handle (4) is fixed to the opposite side, the operator's work can be performed even when the grip is reversed. It is possible to prevent exhaust air from being applied to the hand grip.

It is a center longitudinal cross-sectional view which shows the structure of the air grinder which concerns on this embodiment. It is the II-II sectional view taken on the line of the air grinder which concerns on this embodiment. 3A is a partial cross-sectional view showing the main structure of the exhaust part, and FIG. 3B is a partial cross-sectional view taken along the line bb of FIG. 3A. FIG. 4A is a plan view showing a main part structure of a conventional air grinder, and FIG. 4B is a side view showing a main part structure of a conventional air grinder. It is a fragmentary sectional view showing the modification of the exhaust part of this embodiment.

Explanation of symbols

(1) Air grinder
(2) Air grinder body
(3) Bent end
(5) Exhaust section
(6) Casing
(6a) Body casing
(6b) Drive shaft casing
(6c) Silencer casing
(7) Air motor
(19) Tool drive shaft
(19a) Drive axis
(25) Silencer
(26) First exhaust passage
(27) Exhaust hole
(28) Second exhaust passage
(30) Muffler cover
(31) Silencer
(32) Exhaust valve
(33) Silencer
(34) Exhaust port
(35) Silencer
(37) Guide rod
(38) Muffler spring

Claims (4)

A main body casing (6a) formed in a substantially cylindrical shape from the front end portion to the rear end portion, and a drive shaft casing (6b) protruding in a direction substantially orthogonal to the main body casing (6a) at the front end portion of the main body casing (6a) A casing (6) having:
An air motor (7) built in the casing (6);
A tool drive shaft (19) connected to the air motor (7) and provided in the drive shaft casing (6b);
An air tool provided with an exhaust part (5) for discharging exhaust air of the air motor (7),
An air tool characterized in that the exhaust part (5) is provided at a rear end side position in the drive shaft casing (6b). The air tool according to claim 1,
An exhaust hole (27) for discharging the exhaust of the air motor (7) is formed in the exhaust part (5),
The air tool characterized in that the exhaust hole (27) is inclined with respect to the central axis of the main casing (6a) on a plane perpendicular to the axis of the tool drive shaft (19). The air tool according to claim 1 or 2,
The air motor (7) and the tool drive shaft (19) are connected via bevel gears (12, 22) meshing with each other,
An air tool characterized in that the exhaust air of the air motor (7) flows through the periphery of the bevel gears (12, 22) to the exhaust part (5). The air tool according to claim 1, 2 or 3,
An air tool characterized in that a silencer (25) is attached to the exhaust part (5).

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