JPH03275986A - Delivery valve device of compressor - Google Patents

Abstract

PURPOSE:To substantially eliminate the valve-open resistance of lubricating oil interposed in the blocked area, of a delivery valve so as to damp noise caused by the impact oscillatory wave of the delivery valve by finishing into a rough surface of predetermined roughness the outer periphery of the delivery valve except a circular area of specific width including the edge of an opening. CONSTITUTION:Of the blocked area of a delivery valve around an opening formed by a delivery valve 18, in a valve seat face 16 having an opening of a delivery hole 14 communicated with a compression chamber 10, a circular area of width 0.5 to 1.3mm including the edge 14a of the opening is finished into a rough surface of roughness 10 to 30mum Rz. An outer periphery area Q except the circular area P of specific width including the edge 14a of the opening of the delivery hole 14 is thereby finished into rough surface and this decreases micro contact area so that a rise in valve-open resistance due to surface tension is restrained, and also that the pressure receiving area of the delivery valve 18 is substantially enlarged by compressed refrigerant gas entering the rough surface area Q.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a discharge valve device for a compressor, and more particularly to a discharge valve device having a noise reduction structure.

[Prior Art] A positive displacement compressor used for refrigeration as shown in FIG.
A discharge hole 14 communicating with the discharge hole 14 is provided through the valve plate 12, and a flexible discharge valve 18 is provided on the valve seat surface 16 located on the discharge chamber 22 side of the valve plate 12 to periodically open and close the opening of the discharge hole 14. is installed. The discharge valve 18 is provided independently for each discharge hole 14, or is attached in the form of an integral combination of valve function parts that open and close the openings of a plurality of discharge holes 14, and has a bending limit when the valve is opened. is regulated by the retainer 20. The valve seat surface 16 is generally extremely smooth with a surface roughness of about 2 to 3 μmR2, since it is necessary to ensure not only a tight fit with the discharge valve 18 but also a sealing property with the head member connected to the extending surface. It is finished in good condition.

[Problems to be Solved by the Invention] Fine lubricating oil particles are mixed in the refrigerant gas flowing in the compressor, and both the valve seat surface 16 and the discharge valve 18 are exposed to an environment where lubricating oil particles adhere. It's empty. As mentioned above, since the valve seat surface 16 is finished extremely smooth,
When the discharge valve 18 is opened, the discharge valve 18 is brought into fairly strong contact with the valve seat surface 16 mainly due to the surface tension of the lubricating oil present in the sealed area around the opening of the discharge valve 18 . Therefore, the discharge valve 18 resists opening until the pressure within the compression chamber 10 overcomes the surface tension of the lubricating oil added to the predetermined valve opening pressure, and at the same time as the valve opens, the compressed refrigerant gas suddenly flows into the discharge chamber. is discharged to. As a result, the instantaneous pressure waves of the discharged refrigerant gas accompanied by overcompression and the shock vibration waves of the discharge valve 18 colliding with the retainer 20 are combined to induce noise, and the compression The reality is that such noise is regarded as a problem that cannot be ignored in the operating environment of motor vehicles.

A technical problem to be solved by the present invention is to create a discharge valve device that can effectively reduce noise.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a valve seat surface having an opening of a discharge hole connected to a compression chamber, the opening being a sealed area around the opening by the discharge valve. Width 0.5-1.3mm including edges
A configuration is adopted in which the outer peripheral area excluding the annular boundary area is roughened to 10 to 30 μm R2.

The roughening of the sealed area that alleviates the opening resistance of the discharge valve is
The distal end side in the opening/closing axial direction is particularly effective from the moment applied to the discharge valve. Therefore, it is desirable to set the width of the annular boundary area that excludes surface roughening as small as possible on the tip side, and it is also desirable to set the width of the annular boundary area that excludes surface roughening as small as possible, and to perform substantial surface roughening in the outer peripheral area surrounding the annular boundary area. It can also be applied only to approximately half the area located on the tip side.

When forming the above-mentioned roughened area, as the surface roughness increases, the elevation value of the roughened mountain peak with respect to the above-mentioned annular interface surface also increases. It is preferable to free-cut the roughened area or perform preliminary processing to bulge the annular boundary area.

[Function] In the discharge valve device of the present invention, the outer peripheral area excluding the annular boundary area of a specific width including the opening edge of the discharge hole is roughened,
This results in a microscopic reduction in the contact area, suppressing an increase in valve opening resistance due to surface tension, and furthermore, the pressure receiving area of the discharge valve is substantially expanded by the compressed refrigerant gas entering the roughened area.

Therefore, the discharge valve operates smoothly at a predetermined opening pressure,
Pressure waves of discharged refrigerant gas accompanied by overcompression and vibration waves colliding with the retainer are skillfully damped. Also,
When the discharge valve is under no load, the formation of such a roughened area creates a small gap between the annular boundary area and the annular boundary area.
During the suction stroke, the discharge valve is bent by the pressure difference between the discharge chamber and the compression chamber, and is brought into close contact with the opening edge of the discharge hole, so that its sealing performance is sufficiently ensured. The influence of leakage through the micro-gaps can be more effectively suppressed by adjusting the gap value as described above.

[Example] Hereinafter, an example of the present invention will be specifically described based on the drawings.

1 and 2 show the valve plate 12 portion of the positive displacement compressor illustrated in FIG.
Only the discharge valve 18 that is disposed on the valve seat surface 16 and periodically opens and closes the opening of the discharge hole 14 is shown.

Now, in addition to the valve seat surface 16 being tightly fitted with the discharge valve 18, a head member having a discharge chamber 22 and a suction chamber (not shown) is connected to the extending surface of the valve seat surface 16, so sufficient sealing performance must be taken into consideration. The surface roughness is approximately 2 to 3 μmRZ, and the surface is finished in an extremely smooth state. The valve seat surface 16 has a width of 0.0 mm including the opening edge 14a of the sealing area around the opening of the discharge valve 18 (the annular range indicated by the diameter in FIG. 2).
Only the annular boundary region P of 5 to 1.3 mm is left in the above-mentioned smooth state, and its outer peripheral region Q (drawn to an extent that slightly exceeds the diameter in the figure) is roughened to 10 to 30 μm RZ. Processing methods such as shot blasting, grinding, and knurling can be used to roughen the surface. For example, shot blasting can be performed by masking unnecessary areas.

As described above, in this embodiment, the width of the sealed area on the valve seat surface 16 by the discharge valve 18 including the opening edge 14a is 0.5 to 1.
The outer circumferential area Q excluding the 3 mm annular boundary area P is roughened, and the microscopic reduction in the contact area with the discharge valve 18 is caused by the surface tension of the lubricating oil present in the sealed area, i.e. Effectively reduces valve opening resistance compared to conventional smooth surfaces. Moreover, when the refrigerant gas pressure in the compression chamber rises to near the valve opening pressure, the compressed refrigerant gas intrudes into the roughened area Q from the microgap in the annular boundary area P including the opening edge 14a, causing the discharge valve 1
Since the pressure-receiving area of 8 is substantially increased, the influence of the surface tension is almost eliminated, and the discharge valve 18 operates smoothly at a predetermined valve opening pressure.

Therefore, instantaneous pressure waves of the discharged refrigerant gas accompanied by overcompression and collision vibration waves with the retainer are skillfully attenuated, and noise is satisfactorily suppressed. The formation of such a roughened area Q conversely causes problems in the sealing performance of the discharge valve 18, and gas leakage during the suction stroke tends to become a problem, but the discharge valve 18 during the suction stroke Since it is bent by the differential pressure between the discharge chamber and the compression chamber and tightly collides with the opening edge 14a, its sealing performance is sufficiently ensured (FIG. 3). Of course, in order to achieve more reliable contact with the opening edge 14a, the width of the annular boundary area P and the roughened area Q are
It is more effective to set the surface roughness within a specified numerical value range. In addition, as the surface roughness of the roughened area Q is set larger, the elevation value of the top of the roughened surface with respect to the surface of the annular boundary P (the gap formed with the discharge valve 18) also becomes larger. In order to adjust the thickness to about 5 μm without affecting gas leakage, the roughened area Q is either free-machined in advance depending on the surface roughness, or the annular field MP is adjusted to about 5 μm without affecting gas leakage. It is also possible to process the portion so as to bulge 40.

Although the above-mentioned roughened area Q covers the entire outer circumferential area of the annular boundary area P, it is assumed that the roughened area Q covers the entire outer peripheral area of the annular boundary area P. Even if it is localized, the roughened area Q acts extremely effectively on the moment applied to the discharge valve 18, and can reduce the valve opening resistance accordingly. In addition, due to this moment, the repeated impact force of the discharge valve 18 against the roughened area Q is greater on the tip side, which tends to make the surface roughness of the roughened area Q finer. It is desirable that the width of the annular boundary region P, where Q is excluded, is set to a minimum of about 5 mm on the tip side to ensure a wider effective roughening region Q (FIG. 6).

Figure 7 shows the results of noise level measurements using several samples with the surface roughness of the roughened area Q set at approximately 15 μmRZ and differing only in the width of the annular boundary area P. The rotation speed was 11,000 rpm, and the compression ratio (discharge pressure/suction pressure) was 15/2. However, when the width of the annular boundary region P is set to 1.3 mm or less, compared with the conventional device that does not have the roughened region Q (marked with △ in the figure). It was confirmed that the noise level was successfully reduced by 4 to 5 decibels, and the effectiveness also tended to be saturated.

FIG. 8 shows the results of measuring the relationship between the width of the annular boundary region P and the volumetric efficiency, and is the result of measurements made on the same sample and under the same conditions as in the case of the noise measurement described above. In other words, in the case of this example, the conventional device without the roughened area Q (marked with Δ in the figure)
In addition, an improvement of more than 3% in performance was observed when compared with a sample in which the entire surface of the enclosed area was roughened. As a reference example, the entire area of the enclosed area is 30μ
An extreme decrease in performance was clearly confirmed in the sample whose surface was roughened to mR2 (marked with an X in the figure).

[Effects of the Invention] As described above in detail, the present invention has the configuration described in the claims, so that the valve opening resistance of the lubricating oil present in the blocked area of the discharge valve is substantially reduced. The noise caused by the instantaneous pressure waves of the discharged refrigerant gas that disappears and overcompresses, and the shock vibration waves of the discharge valve that collides with the retainer are well attenuated, and the volume generated by the roughening of the valve seat surface is effectively attenuated. The influence on efficiency can also be suppressed to such an extent that there is no practical problem.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing one embodiment of a discharge valve device according to the present invention, FIG. 2 is an explanatory view showing a roughened area of a valve seat surface, and FIG.
The figure is a sectional view of the main parts similar to Figure 1 showing the bent state of the discharge valve during the suction stroke, and Figures 4 and 5 show preliminary machining to adjust the gap between the discharge valve and the annular boundary area. Figure 6 is an explanatory diagram showing an annular boundary area with unequal width, Figure 7 is a diagram showing the relationship between the width of the annular boundary area and noise, and Figure 8 is a diagram showing the relationship between the width of the annular boundary area and volumetric efficiency. FIG. 9 is a sectional view of a main part of a conventional discharge valve device.

Claims (1)

[Claims] (1) A valve seat surface having an opening of a discharge hole connected to a compression chamber, and an annular boundary area with a width of 0.5 to 1.3 mm including the edge of the opening, of the area sealed around the opening by the discharge valve. 1. A discharge valve device for a compressor, characterized in that an outer circumferential area excluding the area is roughened to a roughness of 10 to 30 μmRz.