JPS5928106Y2 - assembly type piston - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a prefabricated piston having a structure that facilitates replacement and removal of a piston ring and a guide ring that slide on the inner wall surface of a piston cylinder.

In general, components of the piston mechanism of internal combustion engines, compressors, and pumps are designed to withstand the effects of high temperatures and the harmful effects of extreme stress loads; A lot of attention has been paid to it, and various improvements have been made.

Specifically, we tried to eliminate the effects of wear that occurs between the piston skirt and the cylinder inner wall surface, but
As shown in FIG. 1, a typical example is one in which the piston head is not in direct contact with the inner wall surface of the cylinder, but in which a piston ring and a guide ring are fitted onto the outer peripheral surface of the cylinder head.

To explain in detail with reference to the drawings, the overall configuration is such that the piston rod 2 is inserted into a through hole 15 bored in the piston head 1, and the threaded portion 3 at the tip thereof is screwed with a mounting nut 4. Further, the piston head 1 has ring grooves 7 formed on its outer circumferential surface, respectively. It is constructed by fitting a plurality of piston rings 6.6 and guide rings 5, 5 into the piston ring 8.

In this case, the guide ring 6 and piston ring 5 are fitted in the case shown in FIG. 1 as follows.

That is, in the piston ring 5.5, a radial cut is made in a part of the ring in the piston head 1, and the ring groove 7,1 is buried in the expanded state before being fitted. Due to the shrinking force of the inner body, the ring grooves 7, 7
The guide link 6°6 is designed to fit inside the
Unlike the piston rings 5, 5, the state of
The ring groove 8 is heated in the expanded state due to the expansion.
The rings 6 and 6 were fitted into each other, and then fixed by cooling and shrinking the inner body of the rings 6 and 6.

However, in the conventional piston having the above-mentioned configuration, the piston ring deteriorates over time.

To repair the wear of the guide ring, the wear of the annular groove in which the rings are fitted, or the damage to the rings that occurs suddenly, the guide ring 6. .6 The inner body does not have a cut on the circumference, so it needs to be cut out anew, and if the ring groove wears out, the entire piston head itself has to be replaced, so repair work is difficult. In addition to being extremely complicated, the repair cost is also high.

In view of the above-mentioned points, the present invention is an assembly-type piston that uses a cartridge-type ring retaining ring with rings pre-installed, without providing multiple annular grooves for fitting rings on the outer peripheral surface of the piston itself. By doing so, the purpose is to provide a piston with low running costs that makes it extremely easy to replace rings due to wear and tear and does not require replacement of the entire piston head itself. is a piston used in compressors, pumps, etc., and includes a rear piston head 9 having an annular recess 12a on the surface that makes sliding contact with the inner circumferential wall of the cylinder and a piston rod through hole 15a in the axial center; A front piston head 10 is provided with an annular recess 12b that forms an annular groove 12 with the annular recess 12a on a surface that makes sliding contact with the inner circumferential wall of the cylinder, and a piston rod through hole 15b is bored in the axial center of the front piston head 10;
The ring retaining ring 11 with the piston ring 5 and guide ring 6 attached thereto is fitted into the annular groove 12, and the front and rear piston heads 9, 10 are screwed onto the piston rod 2 and the threaded portion 3 at its tip using a mounting nut 4. The point is that it is integrally connected and configured.

The present invention will be described in detail below based on the embodiment shown in FIG.

Reference numeral 2 designates a piston rod, which has a threaded portion 3 formed at its tip, and is inserted into a through hole in the front and rear piston heads, which will be described later, to connect and integrate both piston heads.

The piston head includes front and rear piston heads 9.10
The rear piston head 9 has a through hole 15a through which the piston rod 2 passes through, and the rear piston head 9 has a through hole 15a through which the piston rod 2 passes.
An annular recess 12a is provided at a location that comes into sliding contact with the inner circumferential wall surface of 7.

On the other hand, similarly to the configuration of the rear piston head 9, the front piston head 10 is provided with a through hole 15b through which the piston rod 2 passes, and a mounting nut 4 is provided on the extension line of the through hole 15b.
A fitting recess 14 is formed into which the cylinder 17 is fitted, and an annular recess 12 forming an integral annular groove 12 with an annular recess 12a of the rear piston head 9 is formed at a location where the cylinder 17 is in sliding contact with the inner circumferential wall surface of the cylinder 17. 12b is formed.

As described above, the front and rear piston rods 9 and 10 are configured, but when these piston heads 9 and 10 are integrally connected, the piston rings 5 and 5 and the guide rings 6 and 6 are inserted into the ring grooves. 7. 7. 8. 8, the ring retaining ring 11 is installed in advance by a conventional installation method into the annular groove 12 formed by the front and rear piston heads 9 and 10.
Inward 01. ) with the piston heads 9 and 10 facing each other as shown in the figure.In this state, the piston rod 2 is inserted into the respective through holes 15a and 15b, and at the same time, the piston rod 2 is inserted into the respective through holes 15a and 15b. Threaded part 3 at the tip
The mounting nut 4 is fitted into the fitting recess 14 of the front piston head 10, so that both piston heads 9,
10 are integrally connected to form a prefabricated piston.

The assembled piston of the present invention is constructed as described above.
According to this prefabricated piston, the guide ring and piston ring are installed in the ring retaining ring in advance, so even if the rings are damaged or have to be replaced due to their end of life, the piston head is completely replaced with the previous one. However, with this invention, only the ring retaining ring needs to be replaced, just like replacing a cartridge.
When replacing the ring, 1) Since the pin head itself can be separated into front and rear parts, it is extremely easy to replace the ring by simply fitting the ring retaining ring into the annular recess.

Furthermore, if you prepare a unit in which the guide ring and piston ring are attached to the ring retaining ring in advance, repairs can be carried out quickly, which will significantly improve productivity, and the effect this will have will greatly contribute to the industry. It is.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view showing the entire conventional piston, Fig.
The figure is a longitudinal sectional front view showing the assembled piston of the present invention. 1...Piston head, 2...Piston rod, 4...Mounting nut, 5...
Piston ring, 6... Guide ring, 1, 8
... Fitting groove, 9 ... Rear piston head, 10 ... Front piston head, 11 ...
...Ring retaining ring, 12a, 12b...Fitting recess, 13...O ring, 14...Fitting recess, 15a, 15b... ...Piston rod through hole, 17...Piston cylinder.

Claims (1)

[Scope of utility model registration request] A rear piston head 9, which is a piston used in a compressor, a pump, etc., has an annular recess 12a on the surface that slides in contact with the inner circumferential wall of the cylinder, and has a piston rod through hole 15a in the axial center; A front piston head 10 is provided with an annular recess 12b forming an annular groove 12 with the annular recess 12a on a surface that makes sliding contact with the inner circumferential wall of the cylinder, and a piston rod through hole 15b is bored in the axial center, The ring retaining ring 11 with the piston ring 5 and the guide ring 6 attached thereto is fitted into the annular groove 12, and the front and rear piston heads 9,
10 is integrally connected to a piston rod 2 and a threaded portion 3 at the tip thereof by a mounting nut 4.