JPH10277964A - Exhaust air cover for pneumatic nailing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust air cover for a pneumatic nailing machine which can actuate its rotation with ease, and suspend its rotation when air is exhausted. SOLUTION: In a pneumatic nailing machine where compressed air is fed to the inside of a striking cylinder 2 so as to allow a striking piston to be driven, compressed air within the striking cylinder 2 is exhausted out of an exhaust port formed at the center side of a cylinder cap 6 for the striking cylinder 2 thereafter, an annular groove 22 is formed, which houses the outer circumferential periphery 12 of an exhaust air cover 8 made out of an elastic material covering an exhaust port 77. Recessed and projected surfaces are formed, which can be engaged with both the outer circumferential periphery 12 of the exhaust air cover 8 and the surface of the annular groove 22 faced to the aforesaid periphery, and concurrently, a clearance between the recessed and projected surfaces is set up to a certain extent that the recessed and projected surfaces are slightly brought into contact with each other when the exhaust air cover is rotated in a state that there acts no exhaust air pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to an exhaust cover provided at an exhaust port for exhausting blown compressed air in a pneumatic nailing machine.

[0002]

2. Description of the Related Art In a pneumatic tool such as a pneumatic nailing machine operated by compressed air, after using compressed air as power, the air is exhausted from an exhaust port. At this time, an exhaust port is formed in a part of the exhaust cover rotatably mounted on the exhaust port portion of the tool body, and the exhaust direction can be selected by rotating the exhaust cover.

In a conventional pneumatic nailing machine, as shown in FIG. 8, a boss 31 is formed on a cylinder cap 30, and an exhaust cover 33 is fitted to the boss 31 via an O-ring 32. Make up. The exhaust cover 33 is made of synthetic resin or aluminum, and adjusts the interference of the O-ring 32 so that the operator can rotate it but does not rotate easily.

[0004]

However, at the time of exhaust, the compressed air exhausted from the tool acts on the inside of the exhaust cover 33 to inflate the exhaust cover 33.
2, the exhaust cover 33 rotates during exhaust, and a phenomenon occurs. On the other hand, if the interference is increased, the rotation of the exhaust cover 33 at the time of exhaust does not occur, but it becomes difficult for the operator to perform the rotation operation.

As described above, when the high-pressure air is exhausted, the exhaust cover 33 does not rotate due to the force of the exhaust of the compressed air, and the rotating operation for the operator to easily change the exhaust direction is performed. It was required to be able to do this, but meeting both conditions was technically very difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust cover for a pneumatic nailing machine which solves the above-mentioned problems and which can be easily rotated and does not rotate during exhaust.

[0007]

In order to solve the above-mentioned problems, an exhaust cover of a pneumatic nailing machine according to the present invention supplies compressed air into a striking cylinder which slidably accommodates a striking piston. A pneumatic nailing machine for driving a striking piston to drive a nail, and for discharging the compressed air in the striking cylinder from an exhaust port formed at the center side of a cylinder cap of the striking cylinder by returning the striking piston An annular groove formed of an elastic material, such as rubber, for accommodating an outer peripheral edge of the exhaust cover, which is formed of an elastic material such as rubber, is formed outside the exhaust port of the cylinder cap; A concave and convex surface that can be fitted to each other is formed on the surface of the annular groove, and a clearance between the exhaust cover and the concave and convex surface of the annular groove when air pressure is not applied. , Characterized by being set so that contact lightly with each other of a convex surface and a concave surface.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 indicates a body 1 of a pneumatic nailing machine. The body 1 is provided with a striking cylinder 2, a striking piston 3 slidably housed in the striking cylinder 2, and a head valve 4 for opening and closing the striking cylinder 2. The driver 5 is attached to the striking piston 3
Are combined. An injection port (not shown) for slidingly guiding the driver 5 is formed in a lower portion of the body 1, and a nail is supplied to the injection port from a magazine (not shown). At the top of the impact cylinder 2 is a cylinder cap 6
The cylinder cap 6 has an exhaust port 7 at the center.
Are formed. An exhaust cover 8 is attached to an upper part of the cylinder cap 6.

In the above configuration, the head valve 4 is opened as shown in FIG. 2 (the exhaust port 7 is closed) by pulling operation of the trigger lever 25 (see FIG. 3), and the air in the air chamber 9 formed in the body 1 and the like is formed. The nail is driven by driving the percussion piston 3 by supplying compressed air from the upper end of the percussion cylinder 2. Thereafter, the head valve 4 is closed, the exhaust port 7 is opened, the striking piston 3 returns, and the compressed air in the striking cylinder 2 is further discharged from the exhaust port 7 through the exhaust cover 8 to the outside. Be prepared.

As shown in FIGS. 1 to 3, the exhaust cover 8 is made of an elastic material such as rubber and has a dish-like shape. In the center, the insertion hole 11 for the set screw 10
Are formed. A concave portion 13 is formed in an annular shape between the insertion hole 11 and the outer peripheral edge 12. The inside of the recess 13 is filled with a silencing filter 14 on the side of an exhaust hole 18 described later,
It is held in the recess 13 by a metal plate-shaped filter 15. As shown in FIG. 4, the filter 14 is formed by compressing a thin metal wire into a compressed plate, or is made of a porous synthetic resin material.
A vent hole 16 and a baffle plate 16 a are formed on the circumference of a metal plate, and are fixed to a step 17 on the inner wall of the outer peripheral edge 12 of the exhaust cover 8. The baffle plate 16a is for icing by applying the compressed exhaust gas to prevent icing by the filter 14 and clogging. The filters 14 and 15 both disperse the exhaust gas and reduce the exhaust energy.

Further, a part of the outer peripheral edge 12 has an exhaust hole 1.
8 and a large-diameter portion 12a near the bottom of the concave portion 13 and a small-diameter portion 12a near the open side of the concave portion 13.
b. As shown in FIG. 5A, the outer peripheral surface 19 of the small diameter portion 12b is formed in a hexagonal shape, and each corner forms a convex surface 20.

On the other hand, the set screw 10 of the exhaust cover 8 is provided inside the exhaust port 7 of the cylinder cap 6.
Is formed, and an annular groove 22 for accommodating the small diameter portion 12 b of the outer peripheral edge 12 of the exhaust cover 8 is formed outside the exhaust port 7. As shown in FIG. 3, the outer peripheral surface 23 of the annular groove 22 is also formed in a hexagonal shape, and a concave surface 24 is formed by each corner.

The concave surface 24 and the convex surface 20 are not limited to hexagons. Further, instead of a polygon, a configuration in which the uneven surfaces 24 ′ and 16 ′ are formed on both sides as shown in FIG. 6 may be used.

The exhaust cover 8 is attached by accommodating the outer peripheral edge 12 in the annular groove 22 of the cylinder cap 6 and screwing the set screw 10 having the insertion hole 11 inserted into the screw hole 21 of the cylinder cap 6. Have been. The exhaust cover 8 and the concave surface 24 and the convex surface 20 of the annular groove 22 are in a fitted state. In this case, the clearance between the concave surface 24 and the convex surface 20 is set such that the convex surface 20 and the convex surface 20 lightly contact each other when the exhaust cover 8 is rotated in a state where no exhaust pressure is applied. Therefore, when the exhaust pressure acts, the two come into close contact with each other and fit tightly.

According to the above configuration, if the exhaust cover 8 is rotated by hand before operating the nailing machine, the contact between the convex surface 20 and the concave surface 24 of the cylinder cap 6 becomes stronger or weaker. The clearance between the convex surface 20 and the concave surface 24 is such that the contact is light, and since the concave surface 20 is made of an elastic material, the exhaust cover 8 can be easily rotated with a click-like operation feeling. Therefore, when the air pressure is not acting on the exhaust cover 8, the direction of the exhaust hole 18 can be changed to an arbitrary direction in 16 steps by lightly operating the exhaust cover 8 by hand.

Next, when the compressed air is discharged from the exhaust port 7 after the nailing machine is driven into the nail, the compressed air further passes through the filter 14 through the through hole 16 of the exhaust cover 8 and the compressed air from the exhaust hole 18 to the outside. Is discharged. At this time, as shown in FIG. 7, the compressed air acts on the inside of the exhaust cover 8 and the exhaust cover 8 made of an elastic material swells in the outer diameter direction. Therefore, as shown in FIG. Is strongly pressed against the concave surface 24 of the annular groove 22. Therefore, the rotation of the exhaust cover 8 due to the compressed air is effectively prevented.

Accordingly, the exhaust cover 8 of the pneumatic nailing machine is easy to rotate and does not rotate at the time of exhaust.
Can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a pneumatic nailer according to the present invention.

FIG. 2 is a cross-sectional view of the nailing machine during operation.

FIG. 3 is an exploded perspective view of a main part of the nailing machine.

FIG. 4 is a perspective view of a filter.

FIGS. 5 (a) and 5 (b) are explanatory views of the manner of engagement between the exhaust cover and the uneven surface of the cylinder cap.

FIG. 6 is a sectional view of another example of a concave surface and a convex surface.

FIG. 7 is an enlarged sectional view of an exhaust cover portion.

FIG. 8 is a sectional view of a main part of a conventional nailing machine.

[Explanation of symbols]

 2 Impact Cylinder 3 Impact Piston 6 Cylinder Cap 7 Exhaust Port 8 Exhaust Cover 12 Outer Edge 20 Convex 22 Annular Groove 24 Concave

Claims (1)

[Claims] A nail is driven by supplying compressed air into a striking cylinder which slidably accommodates a striking piston to drive the striking piston, and a compression movement in the striking cylinder is caused by a return movement of the striking piston. A pneumatic nailing machine for discharging air from an exhaust port formed at a center side of a cylinder cap of the impact cylinder, wherein the exhaust port is formed of an elastic material such as rubber outside the exhaust port of the cylinder cap. Forming an annular groove for accommodating the outer peripheral edge of the exhaust cover that covers the exhaust cover, forming an uneven surface that can be fitted to the outer peripheral edge of the exhaust cover and the surface of the annular groove opposed thereto, and the exhaust cover and the annular groove. The clearance of the uneven surface was set to such an extent that the uneven surfaces lightly contacted each other when the exhaust cover was rotated in a state where no exhaust pressure was applied. Exhaust cover pneumatic nailing machine, wherein the door.