JPS6314199B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a vane-type rotary compressor.

<Prior art> Conventionally, this type of rotary compressor has a cylinder that has a perfectly circular space inside and has a suction port and a discharge port at appropriate locations on the circumferential wall of the space, and a cylinder that has a circumferential wall in the space. A rotor that forms a crescent-shaped compression chamber extending from a suction port to a discharge port by having its wall surface in contact with a circumferential wall of a space at an appropriate location, and a vane that is provided on the rotor so as to be freely retractable and that is in constant pressure contact with the circumferential wall of the space. As the rotor rotates, the vanes compress the gas to a predetermined pressure, and the gas is discharged from the discharge port.

<Problems to be solved by the invention> However, in such conventional rotary compressors,
The shape of the compression chamber is crescent-shaped, and the cross-sectional area of the part near the suction port and discharge port is small, and on the contrary, the cross-sectional area of the middle part is large.
The rate of change in the compression chamber volume with respect to the rotation angle of the rotor when the compression chamber pressure reaches a specified pressure (dV/dQV:
The volume of the compression chamber (Q: rotation angle of the rotor) is very large, so even if the rotor rotates a little, the volume of this part is large and overcompression occurs.

In other words, in general, even when the pressure in the compression chamber reaches a predetermined pressure, the opening operation of the discharge valve is slightly delayed due to the inertial force of the discharge valve, and this deviation causes the phenomenon of overcompression. The larger the rate of change in the compression chamber volume with respect to the rotation angle of the rotor when the pressure reaches the predetermined pressure, the greater the distance between the rotor circumferential wall and the cylinder inner wall surface (point B) when the compression chamber pressure reaches the predetermined pressure. ) is larger, the above-mentioned overcompression increases, which causes a decrease in compressor efficiency.

<Purpose> The present invention has been made in view of the above-mentioned matters, and is made by bringing the inner circumferential wall of the cylinder and the circumferential wall of the rotor closer to each other in order to narrow the compression chamber between the suction port and the discharge port in the rotational direction of the rotor. In this case, the rate of change of the compression chamber volume with respect to the rotor rotation angle is 0.
By setting the pressure so that the pressure in the compression chamber is close to the specified value (dV/dQ≒0) and by configuring the compression chamber pressure to reach a predetermined pressure when the vane reaches the approach point, overcompression can be minimized and the compressor The aim was to improve efficiency.

<Example> The drawing is a plan sectional view of the vane type rotary compressor of the present invention, and the cylinder 2 has a half diameter R ₃ centered on the point O ₃ .
, and a cylinder 4 having a radius R ₁ and centered at O ₁ which is a predetermined distance away from point O ₃ .
The rotor 5 has vanes 1 that can appear and retract freely, and rotates around a point O ₂ located between the points O ₁ and O ₃ , and its radius R _{2 is equal to the radius R 2} of the cylinder 3 and the cylinder 4.
The rotor 5 is determined to be in contact with the inner circumferential wall surface of the cylinder 2 at the intersection lines A and B, respectively. The positional relationship between the above points O ₁ , O ₂ and O ₃ is as follows: V ₁ is the volume made up of the cylinder 4 with radius R ₃ of cylinder 2 and the rotor 5, and V 1 is the volume made up of the cylinder 3 with radius R of cylinder 2 and the rotor 5. When the _volume of
V ₁ +V ₂ /V ₂ is determined to be equal to the compression ratio. Also, at the intersection line B, there is an extremely small gap between the cylinder 2 and the rotor 5.
The configuration is such that the pressure in the compression chamber becomes a predetermined pressure when the vane 1 of the rotor 5 reaches the gap, and the rate of change in the volume of the compression chamber with respect to the rotor rotation angle is close to 0 in the approach area B (gap). (dV/dQ
≒0V: Volume of compression chamber, Q: Rotation angle of rotor)
It is set so that

Then, the intake gas enters the compression chamber through the suction port 6, is compressed, passes through the discharge port 7, pushes up the discharge valve 8, and is discharged.

At this time, according to the present invention, the compression chamber is brought close to narrow at point B, and the rate of change of the compression chamber volume with respect to the rotor rotation angle is minimized at the approach point, so that the opening operation of the discharge valve 8 is caused by its inertial force. Therefore, even if the timing deviates slightly from the predetermined timing, the change in dV/dQ is very small, so overcompression can be prevented from occurring.

<Effects> As described above, the present invention provides a cylinder which has a space inside and has a suction port and a discharge port provided at appropriate positions on the circumferential wall of the space, and a cylinder which is rotatably provided within the space and which has a circumferential wall surface. a rotor that contacts a circumferential wall of the space at a proper location to form a compression chamber extending from the suction port to the discharge port in the space, and a vane that is provided in the rotor so as to be freely retractable and that is in constant pressure contact with the circumferential wall of the space; a discharge valve device that opens a discharge port when the compression chamber pressure reaches a predetermined pressure; Move closer to make it narrower. At the approach section, the rate of change of the compression chamber volume with respect to the rotor rotation angle is set to be close to 0 (dV/dQ≒0), and the pressure in the compression chamber is set to a predetermined pressure when the vane reaches the approach section. Because of this configuration, the rate of change in the compression chamber volume with respect to the rotor rotation angle can be reduced, over-compression can be prevented, and compression efficiency can be improved, which is a remarkable effect.

[Brief explanation of the drawing]

The drawing shows a plan sectional view of the vane type rotary compressor of the present invention. 1: vane, 2: cylinder, 5: rotor,
B: Approach part.

Claims (1)

[Claims] 1. A cylinder having a space inside and having suction ports and discharge ports provided at appropriate positions on the circumferential wall of the space, and a cylinder rotatably provided within the space,
a rotor whose peripheral wall surface is in contact with the peripheral wall of the space at an appropriate position to form a compression chamber extending from the suction boat to the discharge port in the space;
A vane that is in constant pressure contact with the circumferential wall of the space, and a discharge valve device that opens a discharge port when the pressure in the compression chamber reaches a predetermined pressure, are provided to connect the circumferential wall of the space and the rotor circumferential wall with respect to the rotational direction of the rotor. The compression chamber is brought close to narrow between the suction port and the discharge port, and at this close portion, the rate of change of the compression chamber volume with respect to the rotor rotation angle is close to 0 (dV/dQ
≒0), and the pressure in the compression chamber becomes a predetermined pressure when the vane reaches the approach portion.