JP2014028410A - Pneumatic tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a pneumatic tool comprising an air dust capable of ejecting compressed air from which impurities are adequately removed.SOLUTION: A pneumatic tool is a screw hammer 1 driven by compressed air stored in an accumulator, which comprises: a nozzle 32 including an inflow opening 32b into which the compressed air supplied from the accumulator flows and an ejection opening 32a from which the compressed air flowing through the inflow opening 32b is ejected; and a cyclone mechanism 30 for separating impurities contained in the compressed air flowing into the inflow opening 32b.

Description

  The present invention relates to a pneumatic tool using compressed air as a power source, and particularly to a pneumatic tool provided with an air duster.

  As an example of a pneumatic tool using compressed air as a power source, there is a driving machine such as a nailing machine or a screw driving machine. Some of these pneumatic tools are provided with an air duster for blowing away dust or wood chips generated during the driving operation. For example, Patent Literature 1 describes a driving machine having an air passage for communicating a pressure accumulating chamber in which compressed air is stored and a nozzle from which compressed air is released, and a discharge valve for opening and closing the air passage. . In this driving machine, when the discharge valve is operated, the compressed air stored in the pressure accumulating chamber is discharged from the nozzle, and dust, wood chips, and the like are blown away by the discharged compressed air.

Japanese Patent No. 3385875

  When the air duster mechanism described in Patent Document 1 is mounted on a screwdriver, oil for lubricating the air motor may be discharged from the nozzle of the air duster together with the compressed air. In addition, the compressed air supplied to the pneumatic tool including the driving machine is generally supplied from a portable air compressor connected to the pneumatic tool via a hose, but is supplied from the air compressor. The compressed air contains a small amount of moisture. For this reason, with the compressed air stored in the pressure accumulating chamber, there is a possibility that moisture contained in the compressed air is released from the nozzle of the air duster toward the object (such as a building member).

  An object of the present invention is to realize an air tool including an air duster capable of discharging compressed air from which impurities such as oil and moisture are sufficiently removed.

  In one embodiment of the present invention, the pneumatic tool includes a nozzle including an inlet through which compressed air supplied from the pressure accumulating chamber flows, and a discharge port through which the compressed air flowing from the inlet is discharged. A cyclone mechanism for separating impurities contained in the compressed air flowing into the inflow port.

  In one embodiment of the present invention, the pneumatic tool accommodates the inflow port of the nozzle on one end side, and an expansion chamber whose other side is gradually reduced in diameter as it is separated from the inflow port of the nozzle, and the accumulator chamber An intake passage that communicates with the expansion chamber, an exhaust passage that communicates the expansion chamber with the atmosphere, a first state that closes the intake passage and the exhaust passage, and a second state that opens the intake passage and the exhaust passage And one end of the intake passage communicates with the expansion chamber via an intake port formed on an inner peripheral surface of the expansion chamber, and one end of the exhaust passage is connected to the expansion chamber. The exhaust port communicates with the expansion chamber via an exhaust port formed on the inner peripheral surface of the chamber, and the intake port is formed at a position closer to the inflow port than the exhaust port.

  In one embodiment of the present invention, the intake passage extends along the inner diameter tangential direction of the expansion chamber.

  In one embodiment of the present invention, the pneumatic tool has a handle that extends from the main body housing in a direction intersecting the axis of the main body housing, and an operator that switches the switching valve to the first state or the second state. The operation element is provided on the outer surface of the main body housing and in a region where the thumb of the right hand or the left hand of the operator who holds the handle can reach.

  In one embodiment of the present invention, the operation element is unevenly distributed on the left side in the radial direction from the center of the main body housing so that the thumb of the right hand of the operator holding the handle can reach.

  In one embodiment of the present invention, the operation element is a push-type knob that switches the switching valve from the first state to the second state when pushed in a direction intersecting the axis of the main body housing.

  In an embodiment of the present invention, a driver bit that drives a screw into an object is driven by the compressed air stored in the pressure accumulating chamber.

  In one embodiment of the present invention, a driver blade for driving a nail into an object is driven by compressed air stored in the pressure accumulating chamber.

  According to the present invention, an air tool including an air duster capable of releasing compressed air from which impurities are sufficiently removed is realized.

It is sectional drawing which shows an example of the screwdriver to which this invention was applied. It is a side view of the notch of the screwdriver shown in FIG. It is a top view of the screwdriver shown in FIG. It is sectional drawing along the AA line of FIG. 3, Comprising: It is sectional drawing which shows an air duster part and a cyclone mechanism. It is sectional drawing along the AA line of FIG. 3, Comprising: It is another sectional drawing which shows an air duster part and a cyclone mechanism. (A) is a typical longitudinal cross-sectional view which shows the effect | action of a cyclone mechanism, (b) is BB sectional drawing of (a).

  Hereinafter, an example of a pneumatic tool to which the present invention is applied will be described in detail with reference to the drawings. The pneumatic tool according to this embodiment is a screwdriver using compressed air as a power source.

  A screwdriver 1 shown in FIG. 1 includes a substantially cylindrical main body housing 2. A handle 3 that extends in a direction intersecting the axial direction of the main body housing 2 is integrally formed with the main body housing 2. The handle 3 is a portion that can be grasped by the right hand or the left hand of an operator who uses the screwdriver 1, and a pressure accumulation chamber 4 is formed therein. A plug 5 to which a pressure hose extending from an air compressor (not shown) is connected is provided at the end of the handle 3, and compression is performed from the air compressor to the pressure accumulating chamber 4 via the pressure hose connected to the plug 5. Air is supplied.

  A nose portion 11 that forms a cylindrical injection port 10 that guides a screw toward an object (not shown) (for example, a wall material) is provided at the tip of the main body housing 2. A push lever 12 that reciprocates in the axial direction of the main body housing 2 is provided at the tip of the nose portion 11. The nose portion 11 is attached with a magazine 13 in which a connecting screw in which a number of connected screws are wound in a coil shape is accommodated. The connecting screws housed in the magazine 13 are sequentially separated by a supply mechanism including a screw guide 14 and a feed piston (not shown) provided between the nose portion 11 and the magazine 13, so that the nose portion 11. Are sequentially supplied to the injection ports 10.

  Further, a cylinder 20 and a spindle 21 are accommodated in the main body housing 2. The cylinder 20 and the spindle 21 have a cylindrical shape, and are arranged coaxially in a state where the lower part of the spindle 21 is fitted inside the upper part of the cylinder 20. Two concave grooves 21a extending in the axial direction are formed on the inner wall of the spindle 21 at intervals of 180 degrees. A slider 22 that moves up and down along the concave groove 21 a is disposed inside the spindle 21, and a piston 23 is disposed below the slider 22. The slider 22 and the piston 23 include a shaft member 24 penetrating them. In other words, the slider 22 and the piston 23 are integrated via the shaft member 24. The upper portion of the shaft member 24 protrudes from the side surface of the slider 22 to form two convex portions 24a that fit into the concave groove 21a of the spindle inner wall, and the lower portion of the shaft member 24 protrudes from the lower portion of the piston 23 to form the piston portion 24b. The upper end of the driver bit 25 is attached to the piston portion 24b.

  When the trigger lever 15 is operated in a state where the push lever 12 is pressed against the object, the trigger valve 16 is opened, and the compressed air in the pressure accumulating chamber 4 flows into the spindle 21 through a predetermined flow path. The slider 22, the piston 23, and the shaft member 24 contained therein are linearly driven (pressed down). As a result, the driver bit 25 mounted on the piston portion 24b of the shaft member 24 is also linearly driven (pressed down). As a result, the driver bit 25 is pushed out from the cylinder 20 along the axial direction of the main body housing 2, and the screw supplied to the injection port 10 of the nose portion 11 is driven out toward the object by the pushed driver bit 25. .

  In the main body housing 2 and above the spindle 21, an air motor 26 to which compressed air is supplied in conjunction with the inflow of compressed air to the spindle 21 is accommodated. Is driven to rotate. Specifically, the rotation of the air motor 26 is decelerated by the planetary gear 27 and transmitted to the spindle 21. Here, as described above, the spindle 21 and the slider 22 are integrated by the engagement of the concave groove 21a and the convex portion 24a. That is, the spindle 21 and the slider 22 are spline-fitted, and when the spindle 21 rotates, the slider 22, the piston 23, and the shaft member 24 contained therein are rotationally driven. As a result, the driver bit 25 attached to the piston portion 24b of the shaft member 24 is also rotationally driven. That is, the driver bit 25 is rotationally driven while being linearly driven. Thereby, a screw is rotationally propelled and screwed into an object.

  As shown in FIG. 2, an air duster portion 31 including a cyclone mechanism 30 is provided in the main body housing 2. The structure of the air duster unit 31 will be described mainly with reference to FIGS. The air duster unit 31 includes a nozzle 32, an expansion chamber 33, an intake passage 34 that connects the pressure accumulating chamber 4 (FIG. 1) and the expansion chamber 33, an exhaust passage 35 that allows the expansion chamber 33 to communicate with the atmosphere, and an intake passage 34. And a switching valve 36 provided in the exhaust passage 35 and a push-in knob 37 as an operator.

  The nozzle 32 has a substantially cylindrical shape in which a discharge port 32a is formed on one end surface and an inflow port 32b is formed on the other end surface. As shown in FIG. 3, the discharge port 32 a of the nozzle 32 is exposed to the outside on the outer surface (upper surface) of the main body housing 2, and compressed air for blowing away dust and wood chips from the discharge port 32 a. Is released. In the following description, the end of the nozzle 32 on the side where the discharge port 32a is formed is referred to as the “front end”, and the end on the side where the inflow port 32b is formed is referred to as the “rear end”. There is a case. However, such a distinction is merely a distinction for convenience of explanation.

  As shown in FIGS. 4 and 5, the expansion chamber 33 includes a cylindrical portion 33 a that houses the rear end portion of the nozzle 32, and a conical portion 33 b that is connected to one end of the cylindrical portion 33 a. The conical portion 33b is tapered from one end portion in contact with the cylindrical portion 33a toward the other end portion. In other words, the conical portion 33b is gradually reduced in diameter as the conical portion 33b is separated from the inlet 32b of the nozzle 32 accommodated in the cylindrical portion 33a.

  One end of the intake passage 34 communicates with the expansion chamber 33 via an intake port 38a formed on the inner peripheral surface of the expansion chamber 33, and the other end communicates with the pressure accumulation chamber 4 (FIG. 1). More specifically, an intake port 38a is formed on the inner peripheral surface of the cylindrical portion 33a of the expansion chamber 33 and in a region facing the outer peripheral surface of the nozzle rear end portion accommodated in the cylindrical portion 33a. One end of the intake passage 34 communicates with the expansion chamber 33 through the intake port 38a. In other words, the intake passage 34 communicates with an annular space surrounded by the inner peripheral surface of the cylindrical portion 33a and the outer peripheral surface of the nozzle rear end portion. Further, in the intake passage 34, at least a portion having an arbitrary length from the intake port 38a extends along the inner diameter tangential direction of the expansion chamber 33 (cylindrical portion 33a).

  One end of the exhaust passage 35 communicates with the expansion chamber 33 via an exhaust port 38b (FIG. 6) formed on the inner peripheral surface of the expansion chamber 33, and the other end communicates with the atmosphere. More specifically, an exhaust port 38b is formed on an inner peripheral surface (conical surface) of the conical portion 33b of the expansion chamber 33 and in a region close to the apex, and the exhaust passage is formed through the exhaust port 38b. One end of 35 communicates with the expansion chamber 33.

  As is apparent from the above description and FIG. 6, the intake port 38 a that connects the intake passage 34 to the expansion chamber 33 has a greater flow rate of the nozzle 32 than the exhaust port 38 b that connects the expansion chamber 33 to the atmosphere. It is formed at a position close to the inlet 32b.

  Refer to FIGS. 4 and 5 again. The switching valve 36 is disposed in the middle of the intake passage 34 and the exhaust passage 35 and opens and closes these passages 34 and 35. Specifically, the switching valve 36 includes two on-off valves 36a and 36b arranged in series and integrated. The first on-off valve 36 a is a valve for the intake passage 34 and is disposed in the middle of the intake passage 34. The second on-off valve 36 b is a valve for the exhaust passage 35 and is disposed in the middle of the exhaust passage 35.

  On one end side in the arrangement direction of the two on-off valves 36a and 36b, a spring 39 that constantly urges the on-off valves 36a and 36b in the direction of the arrow a shown in FIGS. On the side, a knob 37 that displaces the on-off valves 36a and 36b in the direction of the arrow b shown in FIG.

  Normally, the on-off valves 36a and 36b are held at the positions shown in FIG. 4 by the bias of the spring 39 (the switching valve 36 is held in the first state). When the switching valve 36 is held in the first state, the intake passage 34 is closed by the open / close valve 36a, and the exhaust passage 35 is closed by the open / close valve 36b. That is, the communication between the expansion chamber 33, the pressure accumulation chamber 4 (FIG. 1), and the atmosphere is blocked.

  On the other hand, when the knob 37 is operated (pressed), the on-off valves 36a and 36b are displaced to the positions shown in FIG. 5 against the bias of the spring 39 (the switching valve 36 is in the second state). Switched). When the switching valve 36 is switched to the second state, the intake passage 34 and the exhaust passage 35 are opened. That is, the expansion chamber 33 communicates with the pressure accumulation chamber 4 (FIG. 1) and the atmosphere. Then, the compressed air stored in the pressure accumulating chamber 4 flows into the expansion chamber 33 through the intake passage 34 and the intake port 38a. At this time, the intake passage 34 extends along the inner diameter tangential direction of the expansion chamber 33, and the intake port 38a is formed on the inner peripheral surface of the expansion chamber 33. Therefore, as shown in FIG. The compressed air flowing into the chamber 33 rotates along the inner peripheral surface of the expansion chamber 33 to form a vortex. As a result, moisture and other impurities contained in the compressed air are separated by centrifugal force, and only compressed air containing no impurities flows into the nozzle 32 from the inlet 32b of the nozzle 32 and is discharged from the outlet 32a. . On the other hand, the impurities separated from the compressed air are guided toward the tip of the expansion chamber 33 (conical portion 33b) along the inner peripheral surface of the expansion chamber 33 by a vortex. Impurities guided toward the tip of the expansion chamber 33 (conical portion 33b) flow out into the exhaust passage 35 together with the remaining compressed air that has not been discharged from the discharge port 32a, and finally pass through the total exhaust passage 100 and handle. 3 (FIG. 1) is discharged into the atmosphere from an exhaust port (not shown) provided at the rear end. Note that the total exhaust passage 100 is also a passage for releasing the compressed air supplied to the spindle 21 and the air motor 26 shown in FIG. 1 into the atmosphere. Therefore, in the present embodiment, the second open / close valve 36b is provided in the exhaust passage 35 to prevent the compressed air exhausted from the spindle 21 or the air motor 26 from flowing from the total exhaust passage 100 through the exhaust passage 35 into the air duster portion 31. doing.

  When the operation of the knob 37 shown in FIG. 5 is released, the on-off valves 36a and 36b are returned to the positions shown in FIG. 4 by the bias of the spring 39 (the switching valve 36 is switched to the first state). The discharge of compressed air from the discharge port 32a of the nozzle 32 is stopped. When the on-off valves 36a and 36b return to the position shown in FIG. 4 by the bias of the spring 39, it is obvious that the knob 37 also returns to the position shown in FIG.

  As shown in FIG. 2, the knob 37 is provided on the outer surface of the main body housing 2 and in a region where the thumb of the right hand or the left hand of the worker holding the handle 3 can reach. Is preferred. In the present embodiment, the knob 37 is offset within the region and to the left in the radial direction with respect to the center of the main body housing 2. By arranging the knob 37 at such a position, the operability of the knob 37 by the thumb of the right hand holding the handle 3 is further improved.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, the present invention can be widely applied to pneumatic tools other than a screwdriver. For example, the present invention can be applied to a nailing machine in which a driver blade for driving a nail into an object is driven by compressed air stored in a pressure accumulating chamber.

  The operation element is not limited to a push-in knob as long as it can switch the switching valve to the first state or the second state. For example, the operating element is a lever that is rotated by the finger of the operator holding the handle, and when the lever is rotated in a predetermined direction, the switching valve is changed from the first state to the second state or the second state. There is also an embodiment that is switched to the first state.

DESCRIPTION OF SYMBOLS 1 Screwdriver 2 Main body housing 3 Handle 4 Accumulation chamber 25 Driver bit 30 Cyclone mechanism 32 Nozzle 32a Release port 32b Inlet port 33 Expansion chamber 34 Intake passage 35 Exhaust passage 36 Switching valve 36a On-off valve (first on-off valve)
36b On-off valve (second on-off valve)
37 Knob 38a Intake port 38b Exhaust port 100 Total exhaust passage

Claims (8)

An air tool that uses compressed air stored in a pressure accumulator as a power source,
A nozzle provided with an inlet through which compressed air supplied from the pressure accumulation chamber flows, and an outlet through which compressed air flowing from the inlet is discharged;
And a cyclone mechanism for separating impurities contained in the compressed air flowing into the inflow port. An expansion chamber that houses the inlet of the nozzle on one end side and that gradually decreases in diameter as the other end side is separated from the inlet of the nozzle;
An intake passage for communicating the pressure accumulation chamber and the expansion chamber;
An exhaust passage for communicating the expansion chamber with the atmosphere;
A switching valve that is switched between a first state that closes the intake passage and the exhaust passage and a second state that opens the intake passage and the exhaust passage;
One end of the intake passage communicates with the expansion chamber via an intake port formed on the inner peripheral surface of the expansion chamber,
One end of the exhaust passage communicates with the expansion chamber via an exhaust port formed on the inner peripheral surface of the expansion chamber,
The pneumatic tool according to claim 1, wherein the intake port is formed at a position closer to the inflow port than the exhaust port.   The pneumatic tool according to claim 2, wherein the intake passage extends along an inner diameter tangential direction of the expansion chamber. A handle extending from the main body housing in a direction intersecting the axis of the main body housing;
An operator for switching the switching valve to the first state or the second state,
2. The operating element according to claim 1, wherein the operating element is provided on an outer surface of the main body housing and in a region where a right hand or a left thumb of an operator who holds the handle can reach. Item 4. The pneumatic tool according to any one of Items 3.   5. The pneumatic tool according to claim 4, wherein the operator is unevenly distributed on a left side in a radial direction from a center of the main body housing so that a thumb of a right hand of an operator holding the handle can be reached. .   The said operation element is a push-type knob which switches the said switching valve from the said 1st state to the said 2nd state, if it pushes in the direction which cross | intersects the axis line of the said main body housing. Item 6. The pneumatic tool according to Item 5.   The pneumatic tool according to any one of claims 1 to 6, wherein a driver bit that drives a screw into an object is driven by the compressed air stored in the pressure accumulating chamber.   The pneumatic tool according to any one of claims 1 to 6, wherein a driver blade that drives a nail into an object is driven by compressed air stored in the pressure accumulating chamber.

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