TW201738032A - Pneumatic tool - Google Patents

Abstract

To provide a pneumatic tool in which an expansion chamber is formed without requiring an increase in the external size of a housing. In this pneumatic tool, a housing has: a cylindrical motor housing section 30A that has a motor-accommodating part 30a and an output shaft-accommodating part 30b which is connected contiguously to an end of the motor-accommodating part 30a, and which accommodates an annular bearing 22 and a motor output shaft extending out of the annular bearing; a tool shaft housing part 30B; and a curved corner housing part 30C that connects the motor housing part 30A and the tool shaft housing part 30B. The output shaft accommodating part 30b has an expansion chamber 36 which is connected to an exhaust connection hole 34 extending radially outward of the annular bearing 22, and which extends in the circumferential direction and the longitudinal axis direction. The expansion chamber 36 is configured to have an inner volume large enough to allow for expansion of exhaust air that passes through the exhaust connection hole 34 and comes into the expansion chamber 36.

Description

Pneumatic tool

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a pneumatic tool equipped with a pneumatic motor, and more particularly to a pneumatic tool that increases the efficiency of operation of a pneumatic motor by providing a large-volume expansion chamber at a position close to the air motor from an exhaust flow path of the air motor.

The pneumatic tool, that is, the pneumatic grinder, generally drives the output shaft relative to the rotary motor of the air motor, and has a tool drive shaft coupled to the rotary drive output shaft via a bevel gear device, and a rotary grinding disc is mounted on the front end of the tool drive shaft (for example, Patent Document 1).

In the pneumatic grinder, in order to improve the operating efficiency of the air motor, it is necessary to reduce the pressure from the exhaust side of the air motor as much as possible, and increase the pressure difference between the pressure on the air supply side and the pressure on the air discharge side of the air motor. Big. For example, in Patent Document 2, the air discharged from the air motor can be expanded by providing an expansion chamber in the exhaust passage to reduce the pressure on the exhaust side.

In the pneumatic grinder described above, the swirling from the air motor is blown to the peripheral wall of the portion in which the bevel gear unit is housed, thereby suppressing the rotation. The lubricating oil scattered by the rotating bevel gear adheres to the peripheral wall, and the lubricating oil adhering to the peripheral wall is peeled off to be attached to the bevel gear again to be efficiently lubricated.

(for example, Patent Document 3) [Advanced technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-98539

[Patent Document 2] Japanese Patent Laid-Open No. 2001-88056

[Patent Document 3] Japanese Patent Laid-Open No. 2010-188463

In order to increase the operating efficiency of the air motor described above, the expansion chamber is provided, and the outer diameter of the casing of the air motor is increased by providing the expansion chamber. In the hand tool such as the pneumatic grinder described above, if the size of the tool is increased, the operator is not easy to hold the pneumatic tool, or the working portion of the front end of the pneumatic tool is not easily recognized, and there is a narrow portion in the corner portion. The problem that space is difficult to work with.

In order to supply the exhaust gas to the bevel gear unit chamber to improve the lubrication efficiency, it is also considered that the exhaust gas from the air motor is directly blown to the bevel gear so that the particles of the lubricating oil associated with the exhaust gas adhere to the bevel gear, but Since the exhaust gas in the bevel gear chamber of Patent Document 3 is high-pressure and high-speed, it is not expected to adhere to the lubricating oil even if it is blown to the bevel gear.

The object of the present invention is to provide a pneumatic tool that does not increase The outer diameter of the pneumatic tool is added and an expansion chamber is provided in the exhaust passage of the air motor, and the bevel gear device is more efficiently lubricated by introducing the decompressed exhaust gas into the bevel gear chamber.

A pneumatic tool according to the present invention includes: a pneumatic motor, a tool drive shaft, an annular bearing portion, a bevel gear device, and a housing; and the air motor includes a rotor that is rotationally driven about a first long-side axis, and is rotatably received a cylindrical rotor case of the rotor, and a motor output shaft extending from one end of the rotor along the first long axis; the tool drive shaft is formed along a first angle with respect to the first long axis a long axis extending; the annular bearing portion closing the end of the rotor case at the one end side of the rotor and axially supporting the motor output shaft; the bevel gear device having: the motor output shaft a first bevel gear at an end, and a second bevel gear that is provided at an end of the tool drive shaft and that meshes with the first bevel gear to drive the motor output shaft and the tool drive shaft; the housing is used for Accommodating the air motor, the annular bearing portion, the bevel gear device, and the tool drive shaft; the housing having a cylindrical motor housing portion, a cylindrical tool shaft housing portion, and a corner housing portion; Cylindrical horse a casing portion extending along the first longitudinal axis direction and having a motor housing portion for housing the air motor and the motor An end portion of the accommodating portion is connected to the annular bearing portion and an output shaft accommodating portion in which the motor output shaft extending from the annular bearing portion is housed; and the cylindrical tool shaft housing portion is for accommodating the tool drive shaft The corner housing portion is bent to connect the end portion of the motor housing portion to the tool shaft housing portion, and the motor housing portion has a circumferential direction extending outward in the radial direction of the rotor housing An exhaust accommodating portion that extends in the direction of the first long side axis and that is exhausted from the rotor case, and the output shaft accommodating portion has a radius that communicates with the exhaust accommodating portion and is formed in the annular bearing portion An exhaust communication hole extending outward in the first longitudinal axis direction and communicating with the exhaust communication hole and extending in the circumferential direction and the first longitudinal axis direction are larger and curved than the exhaust communication hole An expansion chamber having a cross-sectional area and a volume that allows expansion of the exhaust gas entering the expansion chamber through the exhaust communication hole; at least one of the corner housing portion and the output shaft housing portion has: from the expansion The chamber extends and communicates with the The exhaust gas outlet of the outer body.

In the pneumatic tool, the expansion chamber is provided in the output shaft housing portion. The portion of the output shaft housing portion in which the expansion chamber is provided is a portion that accommodates the output shaft extending from the annular bearing portion, and the casing surrounding the output shaft is formed as a thick portion. The expansion chamber is formed to extend in the circumferential direction and the axial direction in the thick portion, thereby forming a large volume for accommodating the exhaust gas without substantially increasing the outer dimensions of the casing. The exhaust gas entering the expansion chamber formed in this manner is greatly decompressed there. Therefore, the pressure on the exhaust side of the air motor can be reduced, and the pressure difference from the air supply side of the air motor can be increased, and the pressure difference can be increased. The operating efficiency of the air motor.

Specifically, the expansion chamber is disposed to be apart from the annular bearing portion in the first longitudinal axis direction, and the exhaust communication hole has the first between the annular bearing portion and the expansion chamber Two communicating hole portions extending in the direction of the longitudinal axis and spaced apart from each other in the circumferential direction.

The expansion chamber extends in the circumferential direction at an angular range of 150 to 180 around the motor output shaft.

Further, the invention further includes a wall surface extending from the expansion chamber and opening to the chamber of the bevel gear device for blowing the exhaust gas to the exhaust gas injection hole of the gear unit.

In this case, it is preferable that the exhaust gas blowing hole blows the exhaust gas toward the tooth surface of the first bevel gear that rotates in the rotational direction.

Embodiments of the pneumatic tool of the present invention will now be described with reference to the accompanying drawings.

10‧‧‧ pneumatic grinding machine

12‧‧‧Rotor

14‧‧‧Rotor cabinet

14a‧‧‧Exhaust port

16‧‧‧Motor output shaft

18‧‧‧Air motor

19‧‧‧ Hole Department

20‧‧‧Tool drive shaft

22‧‧‧Annual bearing

24‧‧‧1st bevel gear

26‧‧‧2nd bevel gear

28‧‧‧Bird gear unit

28a‧‧‧室

30‧‧‧Shell

30A‧‧‧Motor housing

30a‧‧‧Motor storage unit

30b‧‧‧ Output shaft storage unit

30e‧‧‧Support protrusion

30B‧‧‧Tool shaft housing

30C‧‧‧ Corner housing

32‧‧‧Exhaust venting department

34‧‧‧Exhaust communication hole

34a‧‧‧1st communicating hole section

34b‧‧‧2nd connecting hole section

34c‧‧‧3rd communicating hole section

36‧‧‧Expansion room

38, 40‧‧‧Exhaust outlet

42‧‧‧ openings

44‧‧‧Exhaust blowhole

Fig. 1 is a longitudinal sectional view showing a pneumatic grinder according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view showing the lower side axis A of the rotor of Fig. 1 as viewed from below.

Fig. 3 is a view as seen from III-III in Fig. 1 and is a view showing the shape and relationship between the expansion chamber and the exhaust communication hole, and the tool shaft is omitted, and the first bevel gear is displayed in a substantially external shape. .

Fig. 4 is a rear elevational view of the casing when the pneumatic grinder of Fig. 1 is viewed from the back side.

Fig. 5 is a view showing a type in which the exhaust gas is blown to the bevel gear.

As shown in the drawing, the pneumatic grinder 10 as a pneumatic tool of the present invention has a basic configuration of: a pneumatic motor 18, a tool drive shaft 20, an annular bearing portion 22, a bevel gear device 28, a housing 30; the above air motor 18 includes a rotor 12 that is rotationally driven about the first long-side axis A, a cylindrical rotor case 14 that rotatably houses the rotor 12, and an end from the end of the rotor 12 (left end viewed from the drawing) a motor output shaft 16 extending from the first long-side axis A; the tool drive shaft 20 extends along a second long-side axis B that forms a substantially right angle with respect to the first long-side axis A, and a grinding disc is attached to the lower end. D; the annular bearing portion 22 closes a left end portion of the rotor case 14 and pivotally supports the motor output shaft 16; the bevel gear device 28 has a first end provided at a left end portion of the motor output shaft 16. a bevel gear 24 and a second bevel gear 26 that is disposed at an upper end portion of the tool drive shaft 20 and that meshes with the first bevel gear 24 to drive the motor output shaft 16 and the tool drive shaft 20; the housing 30 For accommodating the air motor 18, the annular bearing portion 22, Bevel gear 28, and the tool drive shaft 20. In the illustrated example, the air motor 18 is a vane type motor, and 18a is a vane. The vane 18a is housed in a groove portion formed in the rotor 12 and extending in the radial direction, and is displaced in the radial direction with the rotation of the rotor 12, and is relatively The inner peripheral surface of the rotor case 14 slides. Shown at 14a is an exhaust port that covers the substantially half-cycle interval of the rotor case 14, and the compressed air driven by the rotor 12 is discharged to the outside of the rotor case 14 through the exhaust port 14a.

The casing 30 has a cylindrical motor casing portion 30A, a cylindrical tool shaft casing portion 30B, and a corner casing portion 30C. The cylindrical motor casing portion 30A is along the first long axis A direction. The motor housing portion 30a that houses the air motor 18 and the left end portion of the motor housing portion 30a are connected to each other, and the annular bearing portion 22 and a motor extending leftward from the annular bearing portion 22 are provided. An output shaft housing portion 30b in which the output shaft 16 is housed; the cylindrical tool shaft housing portion 30B for housing the tool drive shaft 20; and the corner housing portion 30C for the left end portion of the motor housing portion 30A The upper end portion of the tool shaft housing portion 30B is curved so as to be coupled.

The motor housing portion 30a extends 360° in the radial direction of the rotor case 14 and extends in the circumferential direction and extends in the direction of the first long-side axis A (along the substantially entire length of the rotor 12) to accommodate the vent hole. The exhaust gas accommodating portion 32 of the exhaust gas of 14a.

The output shaft accommodating portion 30b includes an exhaust communication hole 34 that communicates with the exhaust accommodating portion 32 and extends in the radial direction outward of the annular bearing portion 22 in the first longitudinal axis A direction, and is provided in the secondary bearing portion. An expansion chamber 36 that is spaced apart toward the front and communicates with the exhaust communication hole 34. In the illustrated example, the exhaust communication hole 34 is a first communication hole portion 34a through which the support protrusion 30e that is engaged with the outer circumferential surface of the rotor case 14 of the casing 30 is inserted in the first longitudinal axis A direction. (for example, in the circle The third communication hole portion 34a) that communicates with the communication hole portion 34a and that extends in the radial direction of the annular bearing portion 22, and the second communication hole portion 34b that extends from the outside of the annular bearing portion 22 in the radial direction The communication hole portion 34b extends to the third communication hole portion 34c that communicates with the expansion chamber 36. In the illustrated example, as shown in Fig. 3, the expansion chamber 36 is provided so as to be curved in the circumferential direction to cover approximately 180°, and the two third communication hole portions 34c formed in an arc shape communicate with each other in the circumferential direction of the expansion chamber 36. End part. The expansion chamber 36 has a cross-sectional area larger than the cross-sectional area of any one of the first to third communication hole portions 34a to 34c, and has a volume that allows the exhaust gas to enter the expansion chamber 36 through the exhaust communication hole 34 to expand. . The expansion chamber 36 is preferably formed at an interval angle of about 150 to 180 in the circumferential direction of the two exhaust communication holes 34. In the third embodiment, the two sides of the expansion chamber 36 are provided in the circumferential direction. Extending over the exhaust communication hole 34 extends to cover an angular range of approximately 180°.

At least one of the output shaft housing portion 30b and the corner housing portion 30C (both in the illustrated example) is provided with exhaust outlets 38, 40 that communicate with the expansion chamber 36 and communicate with the outside of the housing 30. The expansion chamber 36 of the present invention is thicker around the annular bearing portion 22 of the output shaft housing portion 30b around the motor output shaft 16 extending from the annular bearing portion 22 in the output shaft housing portion 30b. In part, it is avoided that the size of the periphery of the casing 30 is increased and the exhaust gas from the air motor 18 can be expanded to discharge the expanded exhaust gas from the exhaust outlets 38, 40 to the outside. In the illustrated example, the exhaust outlets 38, 40 are provided on the side surface of the corner housing portion 30B as shown in Fig. 4, and can be provided with an extinguishing sound (not shown). A large opening 42 of material or the like is connected to the outside.

Fig. 5 is a view showing an example of an arrangement of the exhaust gas blowing holes 44 extending from the expansion chamber 36 and opening to the wall surface of the chamber 28a for housing the bevel gear device for expanding The exhaust gas expanded in the chamber 36 is blown to the first bevel gear 24. The exhaust air blowing hole 44 blows the exhaust gas with the lubricating oil particles from the air motor to the first bevel gear 24, and causes the lubricating oil to adhere to the first bevel gear 24, and as shown in the figure, The tooth surface in the direction of rotation is preferred. By attaching the lubricating oil to the surface engaged with the second bevel gear, it is possible to efficiently lubricate. In the present invention, the exhaust gas decompressed and decelerated in the expansion chamber 36 is blown, and the oil can be efficiently attached to the tooth surface of the first bevel gear 24. The reason why the exhaust gas is blown onto the first bevel gear 24 is that the first bevel gear 24 is made smaller than the second bevel gear 26 in order to transmit the deceleration rotation from the first bevel gear 24 to the second bevel gear 26. (The number of teeth is smaller), and it is easier to heat than the second bevel gear 26. Opened to the lower right in FIG. 5 is a hole portion 19 for mounting a spindle lock which is a tool drive shaft 20 which fixes the gear when the grinding disc is replaced and allows the grinding disc to be mounted. Will not rotate.

Although an embodiment of the pneumatic tool of the present invention has been described above, the present invention is not limited thereto. For example, pneumatic tools are not limited to pneumatic grinders, but can also be applied to other pneumatic tools such as pneumatic sanders or pneumatic drives.

10‧‧‧ pneumatic grinding machine

14‧‧‧Rotor cabinet

16‧‧‧Motor output shaft

20‧‧‧Tool drive shaft

24‧‧‧1st bevel gear

30a‧‧‧Motor collection inside

30b‧‧‧ Output shaft storage unit

32‧‧‧Exhaust venting department

34‧‧‧Exhaust communication hole

34a‧‧‧1st communicating hole section

34b‧‧‧2nd connecting hole section

34c‧‧‧3rd communicating hole section

36‧‧‧Expansion room

38, 40‧‧‧Exhaust outlet

42‧‧‧ openings

Claims (7)

A pneumatic tool comprising: a pneumatic motor, a tool drive shaft, an annular bearing portion, a bevel gear device, and a housing; the air motor includes: a rotor that is rotationally driven about a first long axis, and rotatably houses the rotor a cylindrical rotor case and a motor output shaft extending from one end of the rotor along the first long axis; the tool drive shaft is formed along a second length of a predetermined angle with respect to the first long axis The annular bearing portion extends the end portion of the rotor case on the one end side of the rotor and axially supports the motor output shaft; and the bevel gear device has an end portion provided at the motor output shaft a first bevel gear, and a second bevel gear that is provided at an end of the tool drive shaft and that meshes with the first bevel gear to drive the motor output shaft and the tool drive shaft; the housing is for housing The air motor, the annular bearing portion, the bevel gear device, and the tool drive shaft; the housing includes a cylindrical motor housing portion and a tubular tool a shaft housing portion and a corner housing portion; the cylindrical motor housing portion extending along the first longitudinal axis direction and having a motor housing portion for housing the air motor and an end of the motor housing portion And an output shaft housing portion that connects the annular bearing portion and the motor output shaft extending from the annular bearing portion; the cylindrical tool shaft housing portion is configured to receive the tool drive shaft; The corner housing portion is bent to connect an end portion of the motor housing portion to the tool shaft housing portion, and the motor housing portion extends in a circumferential direction outward in a radial direction of the rotor housing body toward An exhaust accommodating portion that accommodates exhaust gas discharged from the rotor case, and an output shaft accommodating portion that communicates with the exhaust accommodating portion in a radial direction of the annular bearing portion. An exhaust communication hole extending outward in the first longitudinal axis direction and an expansion chamber communicating with the exhaust communication hole and extending in the circumferential direction and the first longitudinal axis direction; the expansion chamber is connected to the exhaust gas a larger cross-sectional area of the hole and having a volume that allows the exhaust gas that enters the expansion chamber to pass through the exhaust communication hole to expand; at least one of the corner housing portion and the output shaft housing portion has: The expansion chamber extends and communicates with an exhaust outlet on the outside of the housing. The pneumatic tool according to claim 1, wherein the expansion chamber is disposed apart from the annular bearing portion in the first longitudinal axis direction; and the exhaust communication hole has: the annular bearing portion Two communicating hole portions extending between the expansion chambers in the first longitudinal axis direction and spaced apart from each other in the circumferential direction. A pneumatic tool according to claim 1 or 2, wherein the expansion chamber extends in a circumferential direction at an angular range of 150 to 180 around the motor output shaft. A pneumatic tool according to claim 1 or 2, further comprising: an exhaust air blowing hole extending from the expansion chamber and opening to a wall surface of the chamber in which the bevel gear device is housed, The exhaust gas is blown to the gear device described above. A pneumatic tool according to claim 3, further comprising: an exhaust gas blowing hole extending from the expansion chamber and opening to a wall surface of the chamber for housing the bevel gear device for arranging Air is blown onto the gear unit. A pneumatic tool according to claim 4, wherein the exhaust gas blowing hole is oriented to blow the exhaust gas to a tooth surface facing the rotation direction of the rotating first bevel gear. A pneumatic tool according to claim 5, wherein the exhaust gas blowing hole is oriented to blow the exhaust gas to a tooth surface facing the rotation direction of the rotating first bevel gear.