JPH0511226B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a valve device for a reciprocating compressor, and more specifically, to a method for reducing noise generated by collision between a reed valve and a valve plate. This invention relates to improvements in valve devices.

[Prior Art] Generally, in a reciprocating compressor, a valve plate having a suction hole and a discharge hole formed therethrough is interposed between the bore opening end of a cylinder block into which a piston is inserted and the cylinder head. Of both planes of the plate, a suction reed valve is located on the plane located on the block side, and a discharge reed valve is fastened or jointly fastened on the plane located on the same head side, so that the suction hole and the discharge hole are connected to each other. The opening end is configured to elastically swing open and close. The opening of the discharge reed valve is similarly regulated by a valve holder that is fastened to or together with the valve plate, and the suction reed valve is similarly regulated by a notched groove carved near the opening end of the bore. Its opening degree is regulated.

However, in the compressor valve device described above,
The gas compressed within the bore as the piston moves forward pushes open the discharge reed valve and is discharged into the discharge chamber from the discharge hole. At this time, the discharge reed valve pushed open by strong pressure collides with the valve holder that regulates the valve opening, and the reed valve, which is reversed by this repulsive force, is reversed and collided again by the gas pressure, repeating the reversal. This causes vibration along with the valve holder. on the other hand,
When the piston moves back to the suction stroke,
In addition to the elastic restoring force of the discharge reed valve and the suction force based on the negative pressure in the bore, the high pressure gas in the discharge chamber acts as back pressure, so the discharge reed valve instantly collides with the valve plate. Therefore, the effects of shock and vibration caused by this collision are more severe than those when the valve is opened. In a valve device in which the discharge reed valve, the valve retainer, and the valve plate that repeatedly collide with the discharge reed valve are all made of metal materials, the collision energy and vibration energy are major causes of noise generation.

Moreover, when the rotation speed of the compressor reaches, for example, 9000 rpm, the discharge reed valve rapidly reverses, causing its tip to collide with the valve plate with its tip slightly deformed, resulting in the rigidity of the discharge reed valve being reduced due to the high temperature discharge atmosphere. Combined with the lowering, localized fatigue failure is likely to occur at the tip edge.

[Problems to be Solved by the Invention] Of course, there have already been some inventions aimed at solving the drawbacks of such conventional valve devices, for example,
Publication No. 147304 discloses a valve holder with an elastic coating on both sides to reduce noise and eliminate the need for a gasket, and Japanese Utility Model Application Publication No. 51-22108 discloses a valve holder with an elastic coating applied to both sides to reduce noise and eliminate the need for a gasket. A buffer means is disclosed in which an O-ring is embedded in the periphery of a hole (suction hole) so as to protrude slightly from the valve plate surface.

The former idea absorbs and alleviates the shock generated between the discharge reed valve and the valve holder, but since the valve holder has a small mass, its vibration energy is also very small, and this is due to the gap between the valve plate and the valve plate. The vibrations transmitted through the valve plate to the main body of the compressor do not account for much weight in terms of noise generation, and are therefore sufficiently damped by the elastic coating. Absorbed. On the other hand, vibrations caused by a particularly strong impact between the discharge reed valve and the valve plate are propagated directly from the valve plate, which has a relatively large mass, to the main body of the compressor, and have a considerable influence on noise generation. It is something.

The latter idea is worthy of some praise in that it has an O-ring embedded in the periphery of the discharge hole to alleviate shock vibrations with the valve plate. There are potential disadvantages described below.

That is, as shown in FIG. 6, the discharge reed valve V
When the valve V is closed by the suction action, the valve V is closed by the valve plate P.
After colliding with part A of the O-ring buried above and jumping once, it collides with part B of the O-ring as shown by the chain line, and during this time the discharged gas flows back into the bore, reducing compression efficiency. Not only this, but also tensile stress concentrates on the C portion of the valve V, accelerating fatigue deterioration of this portion.

The main technical problem to be solved by the present invention is to reduce the generated noise based on simple means, and a secondary problem is to alleviate the stress on the reed valve.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the first invention provides at least one planar surface layer of the valve plate facing the discharge reed valve with at least one layer separated from the main body of the valve plate. A technical measure has been taken to form it from a thin metal plate.

The metal thin plate mentioned above can be made of a steel plate with a thickness of 0.1 to 0.7 mm, more preferably 0.1 to 0.3 mm, and is formed into two layers by selectively combining pieces of the same thickness or different thicknesses. You can also do that. Incidentally, if the other plane surface layer of the valve plate facing the suction reed valve is also formed of the thin metal plate, noise reduction will be more effective.

The second invention employs a configuration in which a buffer thin film is further interposed on the back surface of the metal thin plate.
The buffer thin film is made by attaching synthetic rubber or synthetic resin to the back surface of the thin metal plate by baking or adhesion, and the buffer thin film is applied onto the main body of the valve plate in contact with the thin metal plate. It's okay. The thickness of the buffer thin film is about 30 to 300 μm, more preferably 65 μm.
~120μm.

[Embodiment] FIG. 1 shows the main parts of a swash plate compressor equipped with an embodiment of the valve device according to the first invention.
4, there are suction holes 1 communicating with the bores 12, respectively.
6 and a discharge hole 18 are interposed therebetween, and a suction reed valve 22 is disposed on the plane located on the cylinder block 10 side of both planes of the valve plate 20.
A discharge reed valve 24 is also fastened to the plane located on the side of the cylinder head 14 so as to elastically swing open and close the opening ends of the suction hole 16 and discharge hole 18, respectively. The opening degree of the discharge reed valve 24 is regulated by a valve holder 26 which is similarly fastened together with the valve plate 20, and the suction reed valve 22 is regulated by a notched groove 28 carved near the opening end of the bore 12. Similarly, the degree of opening is regulated.

Both planar surface layer parts of the valve plate 20 are formed by a thin metal plate 20b separated from the main body part 20a of the valve plate 20, and the thin metal plate 20b is made of a steel plate having a thickness of 0.3 mm.

According to such a configuration, although the thin metal plate 20b momentarily vibrates violently due to the closing impact of the discharge (suction) reed valve 24, the vibration of the thin metal plate 20b, which has a small mass, is rapidly dissipated. Since the minute gap interposed between the valve plate main body part 20a and the valve plate main body part 20a prevents the transmission of vibrations, the vibration of the valve plate main body part 20a, which has a relatively large mass, becomes extremely small. Therefore, the vibration energy transmitted from the valve plate 20 to the main body of the compressor, that is, the generation of noise, is steadily reduced.

By the way, according to the results of measuring the noise level of the compressor equipped with the valve device of this example using a noise indicator, the noise level was reduced by approximately 2 dB over the entire rotation range compared to a compressor equipped with a conventional device with a single valve plate. Recorded.
Note that by selecting the relative thickness of the valve plate main body portion 20a and the thin metal plate 20b, it is possible to shift the natural frequency of the valve plate 20 from a frequency range where it easily resonates with the vehicle. This makes it possible to skillfully avoid resonance.

FIG. 2 shows the main parts of a compressor equipped with another embodiment of the valve device according to the first invention, and the feature of this embodiment is that the thin metal plate 20b forming the surface layer of both planes of the valve plate 20 is It has a two-layer structure, with two thin metal plates
For 0b, steel plates with a thickness of 0.15 mm are used for both the first and second layer parts.

According to such a configuration, the vibration energy transmitted by the micro gaps between the laminated metal thin plates 20b is further attenuated, so that even in the measurement results by the noise indicator, it is different from that of the conventional valve device. A reduction effect of approximately 3dB was recorded compared to a compressor.

FIG. 3 shows the main parts of a compressor equipped with an embodiment of the valve device according to the second invention. This is because a buffer thin film 30, indicated by a bold line in the figure, is attached to the back surface. The buffer thin film 30 is a thin metal plate 2
Nitrile rubber latex was applied to the surface of the material 0b using a roller coater and vulcanized and bonded by heat treatment, and the film thickness was adjusted to 100 μm.

According to such a configuration, vibrations caused by impact with the discharge reed valve 24 are temporarily replaced with high-frequency vibrations that are easily attenuated by the thin metal plate 20b, which has a small mass, and this vibration is transmitted to the back surface of the thin metal plate 20b. Since the applied buffer thin film 30 provides further effective attenuation, the noise level is significantly reduced, particularly in the frequency range of 800 to 1500 Hz, where noise levels tend to be high and problematic.

Figures 4 and 5 show the noise spectrum at 4,500 rotations, with Figure 4 for a compressor equipped with the valve system of this embodiment, and Figure 5 for a compressor equipped with the conventional valve system described above. This is due to the use of a compressor. As is clear from the comparison in the same figure, the compressor equipped with the valve device of this embodiment has a
In the frequency range of 800 to 1500Hz, it shows a reduction effect of 11dB.

On the other hand, since the stress of the discharge reed valve 24 based on the collision energy is greatly alleviated by using the valve device of this embodiment, damage or cracks were not caused in the leading edge of the valve in the conventional durability test at 9000 rpm (50 hours of continuous operation). No abnormalities were observed in the discharge reed valve 24 tested up to 13,000 rpm, demonstrating a significant improvement in durability. Note that the buffer thin film 30 may be applied on the valve plate main body portion 20a in contact with the back surface of the thin metal plate 20b, or the same structure may be applied to the valve plate 20 facing the suction reed valve 22. If applied to the other flat surface layer, it is even more effective in reducing noise.

[Effects of the Invention] As explained above in detail, the valve device of the present invention has at least one plane surface layer of the valve plate facing the discharge reed valve formed of at least one layer of thin metal plate separated from the main body of the valve plate. Therefore, the impact energy of the discharge reed valve against the valve plate is replaced by high-frequency vibrations that are easily attenuated by the thin metal plate with small mass, and furthermore, the impact energy of the discharge reed valve against the valve plate is replaced by high-frequency vibrations that are easily attenuated by the thin metal plate with small mass. Since the vibration is effectively damped by the valve plate, the generation of vibrations or noise transmitted from the valve plate to the main body of the compressor is significantly reduced.

In addition, when a thin buffer film is interposed on the back surface of the thin metal plate, the damping effect of the thin buffer film not only further enhances the noise reduction effect, but also contributes to alleviating stress on the discharge reed valve. The durability of the valve can be greatly improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a main part of a compressor equipped with an embodiment of the valve device according to the first invention, FIG. 2 is a cross-sectional view of a main part of a compressor equipped with another embodiment of the valve device, and FIG. is a sectional view of a main part of a compressor equipped with an embodiment valve device according to the second invention, and FIG. 4 is a graph showing a noise spectrum of a compressor equipped with a valve device according to the second invention.
FIG. 5 is a similar graph of a compressor equipped with a conventional valve device, and FIG. 6 is an explanatory diagram showing an example of a conventional valve device. 10...Cylinder block, 12...Bore, 1
4...Cylinder head, 16...Suction hole, 18...
...Discharge hole, 20... Valve plate, 20a... Valve plate main part, 20b... Metal thin plate, 22... Suction reed valve, 24... Discharge reed valve, 26... Valve holder, 3
0...Buffer thin film.

Claims (1)

[Scope of Claims] 1. A valve plate having a suction hole and a discharge hole, and a suction and discharge valve that is fastened to both planes of the valve plate and elastically swings to open and close each opening end of the suction hole and discharge hole. A valve device equipped with a reed valve, characterized in that at least one plane surface layer portion of the valve plate facing the discharge reed valve is formed of at least one layer of thin metal plate separated from the main body portion of the valve plate. Compressor valve device. 2. A valve comprising a valve plate having a suction hole and a discharge hole, and a suction and discharge reed valve that is fastened to both planes of the valve plate and elastically swings to open and close each opening end of the suction hole and discharge hole. In the apparatus, at least one plane surface layer of the valve plate facing the discharge reed valve is formed of at least one layer of thin metal plate separated from the main body of the valve plate, and a buffer is provided on the back surface of the thin metal plate. A compressor valve device characterized by having a thin film interposed therein.