JPH0540306Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a valve device for a reciprocating compressor, and more specifically, to reduce 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 degree 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 provided 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 suction force based on the elastic restoring force of the discharge reed valve and the negative pressure in the bore, the high-pressure gas in the discharge chamber acts as back pressure. 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 holder, 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 this, localized fatigue failure is likely to occur at the tip.

[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, the invention proposed in 1973-
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 slightly protrude 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. Since the vibrations are further attenuated by the elastic coating, the vibrations transmitted to the main body of the compressor through the valve plate do not account for a large weight in terms of vibration 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. 4, 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 present invention forms at least one planar surface layer of the valve plate from an elastic thin plate separated from the main body of the valve plate, and The cross-sectional area of the through hole in the valve plate is set larger than that of the elastic thin plate, and an appropriate number of recesses are arranged around the through hole on the main body of the valve plate.

A steel plate, fiber-reinforced plastic, etc. can be used for the elastic thin plate, and its thickness is appropriately selected depending on the material properties, but is 0.1 to 0.7
Approximately mm is desirable.

The through holes penetrating through the main body of the valve plate and the elastic thin plate may both be formed to have a circular cross section, and the former through hole may be formed concentrically and with a larger diameter than the latter through hole. However, it is also possible to form so-called irregular cross-sectional shapes, such as making the former through hole locally larger than the latter through hole, or the latter through hole locally smaller than the former through hole. There is no problem.

The concave portions arranged around the through hole on the main body of the valve plate may have any shape and size and be configured as a group of multiple independent concave portions, or may simply be a group of concave portions arranged in the vicinity of the through hole on the main body portion of the valve plate. It is also possible to form an annular recess concentric with the hole.

[Function] When the suction or discharge reed valve opens due to the pressure of the flowing refrigerant gas, the gas pressure acts on the edge of the hole in the elastic thin plate that extends into the projected area of the hole in the main body of the valve plate. Since the affected peripheral area of the elastic thin plate is deformed and floated around the area, the refrigerant gas enters into the recessed part through the gap formed by this floating. The energy of the collision with the valve plate when the reed valve closes is replaced by high-frequency vibrations that are easily attenuated by the thin elastic plate with small mass, and furthermore, the energy generated by the collision with the valve plate when the reed valve closes is replaced by high-frequency vibrations that are easily attenuated by the thin elastic plate with small mass. In addition to being attenuated, the impact force of the reed valve is more effectively absorbed and alleviated by the damper action based on the compression reaction force of the refrigerant gas trapped within the recess.

In addition, even if the provision of the recessed portion is omitted, as the elastic thin plate deforms and floats around the edge of the through hole, it may enter the gap formed between the main body of the valve plate. The refrigerant gas, especially the mixed lubricating oil particles in the gas, remain and exert a corresponding buffering effect when the reed valve is closed.

[Embodiment] Figure 1 shows the main parts of a swash plate compressor equipped with an embodiment of the valve device of the present invention.
A valve plate 20 is interposed between the open end of the bore 12 and the cylinder head 14, and a valve plate 20 is provided with a suction hole 16 and a discharge hole 18, each communicating with the bore 12.
Of both planes of the valve plate 20, the cylinder block 10
A suction reed valve 22 is fastened to the plane located on the side, and a discharge reed valve 24 is fastened to the plane located on the cylinder head 14 side. It is made to open and close elastically. 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 controlled by a notched groove 28 provided near the opening end of the bore 12. Similarly, the degree of opening is regulated.

Both plane surface parts of the valve plate 20 are formed by elastic thin plates 20b made of a 0.3 mm steel plate separated from the main body part 20a of the valve plate 20, and each reed valve 2
The through hole 16 of the elastic thin plate 20b facing 2 and 24
a, 18a are through holes 1 of the valve plate main body portion 20a.
It is concentric with 6 and 18 and has a small diameter. And each through hole 16, 1 on the valve plate main body part 20a
8, there are independent and symmetrical curved bead-shaped recesses 30 and 32 around the periphery.
is installed.

This aspect is clearly shown in FIG. 2, which shows only the valve device portion related to the discharge reed valve 24 in an enlarged manner, but the shape, size, number, etc. of the recessed portion 32 are different from the present embodiment. For example, the concave portion 32 may be formed into a single annular shape, or a plurality of the same or different concave portions 32 may be arranged irregularly.
That is, by appropriately and selectively combining the material properties and thickness of the elastic thin plate 20b and the specifications of the recessed portions 32, it is possible to select a frequency range that particularly requires suppression. .

Therefore, according to the present embodiment of the valve device having the above-described configuration, when the discharge (suction) reed valve 24 opens due to refrigerant gas pressure, the valve plate main body 20a and the elastic thin plate 2
Due to the difference in cross-sectional area between the through holes 18 and 18a, which are penetrated through the through holes 18 and 18a, the gas pressure acts on the edge of the through hole 18a that extends into the projected area of the through hole 18, and the elasticity is Since the affected peripheral area of the thin plate 20b is deformed and floated, the refrigerant gas containing lubricating oil particles flows into the recessed portion 32 through the gap formed by this floating.
invade inside. When the discharge reed valve 24 closes, the thin elastic plate 20b momentarily vibrates due to the closing impact, but the vibration of the thin elastic plate 20b, which has a small mass, is rapidly dissipated, and in addition, the valve plate main body portion 20a Since the micro gap interposed between the valve plate and the valve plate prevents the transmission of vibration, the vibration of the valve plate main body portion 20a, which has a relatively large mass, becomes extremely small. Moreover, in the valve device of this embodiment, the impact force of the discharge reed valve 24 is more effectively absorbed and alleviated by the damper action based on the compression reaction force of the refrigerant gas trapped in the recessed portion 32. The generation of vibrational energy or noise transmitted from the plate 20 substantially to the compressor body is significantly reduced.

FIG. 3 shows the noise level for each compressor using each valve device. In this experiment, a valve device in which the feature of the present invention was adopted only on the discharge reed valve 24 side was used in Example 1. , same configuration as suction reed valve 2
A valve device also adopted on the second side is referred to as Example 2, and a conventional valve device in which the entire surface of the valve holder 26 is coated with elasticity is added as a comparative example. In the experiment, the compressor was directly connected to a variable speed electric motor, and the rotation speed was increased to 5000 rpm in about 3 minutes.
The sound level was measured using an indicating sound level meter. As is clear from the figure, the valve device of Example 1 showed a reduction effect of more than 8 dB in the entire rotation range regardless of high and low speeds compared to that of the comparative example, and was particularly noticeable in the rotation range of around 4000 rpm. This shows a significant reduction effect.

The damping effect of the refrigerant gas, which is one of the characteristics of the device of the present invention, has different damping characteristics compared to a normal solid elastic body, and is not expected to occur in the low frequency range of several hundred Hz or less, for example. Since it is also effectively involved in the damping of vibrations, vibration reduction can be achieved in an extremely wide frequency range. Furthermore, it was clearly demonstrated from the above experimental results that the valve device of Example 2 was more effective in reducing the noise level.

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 abnormality was observed in the discharge reed valve 24 tested up to 13,000 rpm, demonstrating a significant improvement in durability.

[Effects of the invention] As explained in detail above, the valve device of the present invention has at least one planar surface layer of the valve plate formed of an elastic thin plate separated from the main body of the valve plate, and
The cross-sectional area of the through hole in the main body of the valve plate is set larger than that of the elastic thin plate, and an appropriate number of recesses are arranged around the through hole on the main body of the valve plate.
The impact energy of the reed valve against the valve plate is replaced by high-frequency vibrations that are easily attenuated by the thin elastic plate with a small mass, and is skillfully attenuated by the microgap between the valve plate and the main body. The impact force of the reed valve is more effectively absorbed by the damper action based on the compression reaction force of the refrigerant gas trapped in the recessed part, so vibrations are substantially transmitted from the valve plate to the main body of the compressor. That is, noise is significantly reduced. In addition, the damper action of the refrigerant gas not only reduces noise but also contributes to stress relief in the reed valve, thereby significantly improving the durability of the reed valve.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the main parts of a compressor equipped with an embodiment of the valve device according to the present invention, Fig. 2 is an enlarged plan view showing the discharge reed valve portion of the same valve device, and Fig. 3 is the noise level obtained from noise experiments. FIG. 4 is an explanatory diagram showing an example of a conventional valve device. 10...Cylinder block, 12...Bore, 1
4... Cylinder head, 16, 16a... Suction hole, 18, 18a... Discharge hole, 20... Valve plate,
20a...Valve plate main part, 20b...Elastic thin plate, 2
2...Suction reed valve, 24...Discharge reed valve, 3
0,32...Concave portion.

Claims (1)

[Claims for Utility Model Registration] (1) A valve plate through which suction and discharge passages are provided, and a valve plate that is fastened to both flat surfaces of the valve plate and elastically swings each opening end of the passage hole. In a valve device equipped with a reed valve that opens and closes, the planar surface layer of at least one of the valve plates is formed of an elastic thin plate separated from the main body of the valve plate, and the cross-sectional area of the through hole of the main body of the valve plate is A valve device for a compressor, characterized in that: is set larger than that of the elastic thin plate. (2) The valve device according to claim 1, which is a registered utility model, characterized in that an appropriate number of recesses are arranged around the through hole on the main body of the valve plate.