JP2514696Y2 - Piston seal device for driving machine - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston seal device for a driving machine for driving a fastener such as a nail by using compressed air as a power source.

[0002]

BACKGROUND OF THE INVENTION Figure 3 shows one example of a conventional fastener driving tool, the ball striking driving machine is, as is well known, operating the operating valve 7 draw trigger 8, the main valve 6 is raised The compressed air accumulated in the open air chamber 2 flows into the upper portion of the piston 4, and the piston 4 rapidly descends in the cylinder 3 and drives the stopper 13 already fed into the injection port 9. As further shown in FIG. 4
To long oilless structure of life, a groove 11 is provided on the outer periphery of the piston 4, accommodating a piston ring 10 which is biased by an O-ring 5 and the O-ring 5 is urging body within the groove 11 However, when the piston 4 slides in the cylinder 3, the outer periphery of the piston ring 10 is always inside the cylinder 3.
The peripheral surface so as to press urging maintains the airtightness of the sliding surfaces of the piston 4 and the cylinder 3.

In the above oil-free structure, in order to prevent the outer peripheral portion of the piston 4 from directly hitting the inner peripheral portion of the cylinder 3 and being damaged at the time of impact, the outer peripheral portion of the piston 4 is covered by the cylinder 3.
There is a sufficient gap to the inner circumference of the to avoid contact.

[0004]

In the conventional oil-free structure piston 4, a drive bit 12 having a convex or flat cross section for driving a stopper 13 such as a nail having a small wire diameter.
In driving machine having a load in the vertical direction occurs at impact
Then , an excessive load is applied to the drive bit 12. That is, stop 13 as is shown in Fig. 6 Tsu clogging in the injection port 9 above
If the stopper 13 is not fired from the ejection port 9 by the action, the drive bit 12 in the middle of striking is prevented from moving at the tip. However, the piston 4 upper continue because there is a gap <br/> that between the compressed air is supplied between the piston 4 and the cylinder 3 together, the piston 4 as shown in FIG. 5 inclined in the cylinder 3 . Therefore, a bending moment acts on the drive bit 12 due to the load in the vertical direction, which in turn causes the drive bit 12 to be bent and promote buckling, resulting in the drive bit 1
2 has a drawback that it cannot be used due to plastic deformation.

Further, the piston of Japanese Patent Publication No. 62-47157 is provided with two O-rings so that the piston is hard to incline. However, since the aim of anti-tilt piston only O-ring in this structure, when the stop has not been fired from the injection port, Mai was O-ring travels large impact on the drive bit is deflected, the conventional consequently examples Drive bit 12 buckles like
There was a drawback that it would end up. The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to easily buckle the drive bit.
Providing a piston seal device that can be prevented with various configurations
It is to today.

[0006]

SUMMARY OF THE INVENTION The above object is achieved, piston Li
The piston ring in the sliding direction of the piston and
The inner peripheral surface near both sides of the
It is achieved by configuring to bear .

[0007]

According to the driving machine with the piston seal device configured as described above, when the drive bit receives an excessively large load in the sliding direction due to shock, the inclination of the piston is minimized .
And consequently buckling of the drive bit
become able to.

[0008]

1 and 2 show an embodiment of the present invention. FIG.
In, the main configuration and operation for driving the stopper 13 are the same as those in the related art. Figure 2 shows the piston seal of the present invention.
It is the A section enlarged view of FIG. 1 which shows an apparatus . The outer periphery of the piston 4 up and down sliding in the cylinder 3, the vertical direction of the piston ring bearing 4a provided with a shallow groove 11 with a piston ring bearing 4a for housing the piston ring 10 in contact with the cylinder 3 an inner surface substantially It is provided with deep grooves 11a for accommodating the O-ring 5 in the center. The piston ring 10 is utilized by utilizing the elastic force of the O-ring 5 housed in the deep groove 11a.
Is constantly urged against the inner surface of the cylinder 3 .

The piston ring 10 is made of, for example, a material in which a polyimide resin is contained in a tetrafluoroethylene resin, and the applicant of the present application filed Japanese Utility Model Application No. 63-101301.
The effect that the piston ring 10 described in Japanese Utility Model Publication No. 23970/1990 is less worn and a long-life oilless structure driving machine can be provided. That is, since the piston ring 10 is made of these materials, the mechanical strength of the piston ring 10 can be higher than that of a rubber ring made of rubber or the like. This is described in Nikkan Kogyo Shimbun "Industrial Materials" January 1985 issue (Vol. 33, No. 1), reprint, page 102, Table 2, general characteristics of keluside and quinel.

[0010] Such a piston ring 10, as shown in FIG. 2, the elastic force between the piston ring bearing 4a and the piston ring 10 when housed in the shallow groove 11 does not occur. Accordingly the piston ring 10 is also large impact on the piston 4 I I transfer may prevent the piston 4 on the inner surface of the cylinder 3 by the deflection of the O-ring 5 to be supported by the piston ring bearing 4a is in contact.

FIG. 7 shows another embodiment of the present invention. Figure 7 is top side piston ring 10a and a lower piston ring 10 with respect to the sliding direction of the piston ring 10 of the embodiment shown in FIG. 2
It is configured by being divided into two parts b . Even with such a configuration, even if the O-ring 5 bends due to an excessive load, the piston rings 10a and 10b are supported by the piston ring support portion 4a, so that the piston 4 does not tilt, and the piston is not attached to the inner surface of the cylinder 3. 4 can be prevented from contacting and damaging both.

[0012]

As described above , according to the present invention, the piston ring is directly supported near both sides in the sliding direction of the piston ring.
Since the drive bit is shocked in the sliding direction and an excessive load is applied, the piston may tilt .
And , as a result, prevent the drive bit from buckling.
You can stop. Also consists of one piston ring
Has a simple structure and is easy to assemble and manufacture.
Operational effects such as ease of operation can be achieved.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view showing an embodiment of the driving tool of the present invention.

FIG. 2A of FIG. 1 showing an embodiment of the sealing device of the present invention
Part enlarged view.

FIG. 3 is a partial vertical sectional view showing an example of a conventional driving machine.

FIG. 4 is an enlarged view of part B showing the piston seal part of FIG. 3.

FIG. 5: FIG. 3 phase showing the buckling deformation state of the drive bit
The partial sectional view of the present.

FIG. 6 is a view on arrow C of FIG.

FIG. 7 is a sectional view of a piston seal portion showing another embodiment of the present invention.

[Explanation of symbols]

3 is a cylinder, 4 is a piston, 4a is a piston ring support portion, 5 is an O-ring, 10 is a piston ring, 11 is a shallow groove, and 11a is a deep groove.

Claims (1)

(57) [Scope of utility model registration request] 1. A drive bit connected to a piston that moves up and down in a cylindrical cylinder using compressed air as a power source.
In a driving machine in which a stopper is driven into a material to be driven, the stopper is provided on the outer circumference of the piston so as to extend in the sliding direction of the piston.
And a shallow groove formed on the inside of the shallow groove.
The deep groove and the O-ring housed in the deep groove,
It is stored in the shallow groove, and the inner wall of the cylinder is surrounded by an O-ring.
With one piston ring biased toward
The piston ring seals between the cylinder and the piston.
Piston seal apparatus of the driving machine, characterized by Le.