JPH02136580A - Valve device of compressor - Google Patents

Abstract

PURPOSE:To prevent the generation of noise due to the pressure wave of the coolant passing through a discharge port by setting the sectional area on the inlet side, in a specific ratio, smaller than the sectional area on an outlet side, in the discharge port which is formed on a valve seat and opened and closed by a discharge valve. CONSTITUTION:Electric motor elements 3 having a rotary shaft 2 is housed in the upper side, and a compression element 4 driven by a rotary shaft 2 is housed in the lower side, inside a sealed container 1. The compression element 4 compresses the coolant which flows into a cylinder 5 by the cooperation of a roller 7 and a vane 8, and when a discharge valve 11 is opened, said coolant is discharged into a cup-shaped muffler body 2 through a discharge port 13. In this constitution, in the discharge port 13, the sectional area of a cylinder side opened port 13 is set smaller than the sectional area of a discharge valve side opened port 15. The ratio between the both sectional area is set within a range of 1.7-2.0. Therefore, the increase of the speed of the pressure wave of the coolant which flows in the discharge port 13, exceeding a sonic wave, is prevented, and the generation of noise due to impact can be dissolved.

Description

[Detailed description of the invention] (b) Industrial application field This invention relates to an improvement in a valve device for a compressor.

(B) Prior Art A conventional compressor is constructed as shown in, for example, Japanese Utility Model Publication No. 11442/1983. Here, a conventional example will be explained with reference to this publication. 3 to 5, reference numeral 50 denotes a compression element installed above the support frame 51, and a valve seat plate 53 and a cylinder head 5 are attached to the tip of the cylinder 52.
4, a piston 58 is coupled to an eccentric pin 57 provided at the upper end of a rotating shaft 56 of an electric element 55, and this piston is reciprocated within the cylinder 52. The valve seat plate 53 is provided with a suction port 60 that communicates between the suction chamber 59 of the cylinder head 54 and the inside of the cylinder 52, and a discharge port 62 that communicates the inside of this cylinder with the discharge chamber 61 of the cylinder head 54. .

The valve seat plate 53 has a discharge port 62 on the cylinder head 54 side.
A discharge valve 63 that opens and closes the suction port 60 is attached to the cylinder 52 side, and a suction valve 64 that opens and closes the suction port 60 is attached to the cylinder 52 side. The discharge port 62 has a discharge valve side opening 65 larger than a cylinder side opening 67 extending into the notch 66 of the suction valve 64, and has a smooth curved surface 68 that gradually increases the gas flow path diameter of both openings. .

In a compressor with this structure, the hole diameter of the discharge port 62 is formed to gradually increase from the cylinder side port 67 to the discharge valve side port 65, so that the refrigerant discharged from the cylinder 52 to the discharge chamber 61 of the cylinder head 54 is In addition to reducing passage resistance, the refrigerating capacity is improved, and the notch 66 of the suction valve 64 is made smaller.
The valve strength is improved by alleviating the degree of stress concentration in step 4.

(c) Problems to be Solved by the Invention However, since the discharge ports 62 are simply increased gradually from the cylinder side port 67 to the discharge valve side port 65,
When the pressure wave of the refrigerant gas discharged from the cylinder 52 into the discharge chamber 61 of the cylinder head 54 exceeds the speed of sound, there is a problem in that an impact of the airflow occurs within this discharge chamber, and noise is generated due to the impact.

In addition, to solve this problem, we installed a resonant muffler in the discharge port, injected oil or liquid refrigerant into the cylinder when pressure waves were generated, and used its mass to attenuate the pressure waves. However, in the former case, the top clearance loss increases, and in the latter case, the pressure when opening the discharge valve increases, resulting in poor efficiency.

This invention solves the above problems, and
The purpose is to prevent the pressure waves of the refrigerant flowing through the pipe from exceeding the speed of sound.

2) Means for Solving the Problems This invention provides a discharge port in the valve seat that seals the opening of the cylinder, and makes the cross-sectional area A on the inlet side of the discharge port smaller than the cross-sectional area B on the outlet side. The ratio of cross-sectional area is B/A=
It is set in the range of 1.7 to 2.0.

(f) Effect By having the above configuration, this invention makes the pressure waves of the refrigerant flowing through the discharge port reach the sonic speed, prevents the pressure waves of the refrigerant flowing out from the discharge port from becoming shock waves, and prevents the pressure waves from becoming shock waves. This is to prevent noise from being generated.

Example) The present invention will be explained below based on the example shown in FIGS. 1 and 2.

Reference numeral 1 denotes a closed container, and in this container there is housed an electric element 3 having a rotating shaft 2 on the upper side, and a rotary compressing element 4 driven by the rotating shaft 2 of this electric element on the lower side. Reference numeral 4 denotes a cylinder 5, a roller 7 that rotates inside the cylinder 5 by an eccentric portion 6 of the rotating shaft 2, a vane 8 that comes into contact with this roller and divides the inside of the cylinder 5 into a low pressure chamber and a high pressure chamber, and an opening of the cylinder 5. an upper bearing part 9 and a lower bearing part 10 for sealing, and a discharge valve 11 attached to the upper bearing part;
It is comprised of a cup-shaped muffler integral 12 that covers this discharge valve. The upper bearing portion 9 is provided with a discharge port 13 that is opened and closed by a discharge valve 11 . In this discharge port, the cross-sectional area A of the cylinder side port 14 is made smaller than the cross-sectional area B of the discharge valve side port 15, and the ratio of this cross-sectional area is B/A.
= range of 1.7 to 2.0. Further, the discharge port 13 has a linear taper shape from the cylinder side opening 14 toward the discharge valve side opening 15.

In the compressor valve device configured as described above, the refrigerant flowing into the cylinder 5 is compressed by the cooperation of the roller 7 and the vane 8. When this compressed refrigerant becomes higher than the pressure inside the cup-shaped muffler unit 12 which is the back pressure of the discharge valve 11 that closes the discharge port 13, the discharge valve is opened and the refrigerant passes through the discharge port 13 into the cup-shaped muffler. Heck 1
2 and is discharged into the external cooling circuit (
(not shown) are circulated.

The discharge port 13 has a cross-sectional area A of the cylinder-side opening 14 smaller than a cross-sectional area B of the discharge valve-side opening 15, and the ratio of this cross-sectional area is in the range of B/A=1.7 to 2°0. By doing so, when the pressure wave of the refrigerant generated by compression in the cylinder 5 passes through the discharge port 13, it is made to have the same speed as sound, and there is no impact of the air flow within the cup-shaped muffler unit 12, and the refrigerant is jetted out smoothly. That's what I do.

That is, since the amount of refrigerant flowing through the discharge port 13 is the same between the cylinder side port 14 and the discharge valve side opening 15, the following formula (2) holds true.

c=aAn, 1f■=aBnzJv■ +t++++++
+■ However, G: flow rate, A, B: cross-sectional area, nl+nff1: section modulus, P: pressure, ■=heavy density, and the formula ■ can be derived from the formula ■.

B=A(nt/nt)...
...■ Also, nl and n are such that the pressure wave of the refrigerant flowing through the discharge port 13 can be made equal to the speed of sound according to the following equations (1) and (2).

nl = gK(2/to+1)(K+1)/(K-1
) ,...,,,... ■However, g: gravitational acceleration,
K: superheated steam coefficient, Pl: pressure inside the cylinder when the discharge valve opens, P: pressure Pl of the discharged refrigerant is 22.5 kg/cm", P is 21.Okg
/Cr1l" and the refrigerant is R-22, K becomes 1.20, and when this value is substituted into the 0 formula and the 0 formula,
nl is 2.03 and n is 1.09.

Therefore, from equation (2), the cross-sectional area B of the discharge valve side port 15 of the discharge port 13 is 1.8 larger than the cross-sectional area A of the cylinder side port 14.
If the size is made six times larger, the pressure wave passing through the discharge port 13 can be made equal to the speed of sound, and noise caused by airflow impact can be prevented.

Also, the pressures P r , P ! Although the coefficient of superheated steam and the coefficient of superheated steam change depending on the operating conditions of the compressor and the refrigerant used, the fluctuations in nl and n due to these changes are slight, and the ratio of the cross-sectional area of the discharge port 13 is set as B/A = 1°. If it is set in the range of 7 to 2.0, the impact caused by pressure waves can be greatly attenuated, and the generation of noise can be suppressed.

(G) Effects of the Invention The valve device for a compressor of the present invention has a discharge port in a valve seat that seals the opening of the cylinder, and has a cross-sectional area A on the inlet side of the discharge port smaller than a cross-sectional area B on the outlet side, In addition, since the ratio of this cross-sectional area is set in the range of B/A = 1.7 to 2.0, the discharge port is widened at the end and the outlet side is 1.7 to 2 degrees larger than the inlet side. By doing this, the speed of the pressure wave of the refrigerant passing through the discharge port can be made equal to the speed of sound, and it is possible to prevent the amount of noise caused by the impact when the pressure wave exceeds the speed of sound.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a rotary compressor showing an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of the valve device, Fig. 3 is a sectional view of a compressor showing a conventional example, and Fig. 4 5 is an enlarged sectional view of the main part of the valve device, and FIG. 5 is a plan view showing the installation on the suction side. 4... Rotating compression element, 5... Cylinder, 9
...Upper bearing part, 11...Discharge valve, 13...
・Discharge port, 14...Cylinder side opening, 15・
...Discharge valve side opening.

Claims (1)

[Claims] 1. A cylinder, a valve seat that seals the opening of this cylinder,
In a compressor valve device, the valve seat is provided with a discharge port that is opened and closed by the discharge valve, and the discharge port has a cross-sectional area of A on the inlet side.
A valve device for a compressor, characterized in that B is smaller than the cross-sectional area B on the outlet side, and the ratio of the cross-sectional areas is in the range of B/A=1.7 to 2.0.