JPS63140882A - Variable-displacement vane type rotary compressor - Google Patents

Abstract

PURPOSE:To reduce the load fluctuation of an engine by driving an actuator operating the control valve of a bypass port communicating a working chamber and an intake chamber with the control pressure and the intermediate pressure between the discharge pressure and intake pressure. CONSTITUTION:The opening of a bypass port 14 communicating a working chamber and an intake chamber is controlled by a control valve operated by an actuator 17. The actuator 17 is driven by the control pressure of the intake pressure or discharge pressure and the intermediate pressure between the discharge pressure and intake pressure. Accordingly, the variable range of the discharge quantity can be increased, and the load fluctuation of an engine can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a variable capacity vane type rotary compressor used, for example, as a refrigerant compressor for an automobile air conditioner.

(Prior art) In general, in a vane type rotary compressor, in order to variably control the discharge amount, a suction port that opens into the cam ring is provided in a side plate that seals one end of the cam ring, and the opening position is aligned with the cam surface. By moving along the vane, the compression start point of the vane is changed and the discharge amount is controlled.

Conventional variable capacity vane type rotary compressors of this type include:
For example, it is known to have a front plate formed with an arc-shaped bypass port that opens to substantially the entire area of the working chamber, and a movable plate having an arc-shaped bypass opening between the front plate and the cam ring. In this compressor, a movable plate is rotated by an electric motor provided inside or outside the compressor, and the position of the bypass opening is changed to thereby perform variable control of the discharge amount.

However, in the above device, since the movable plate is rotated by an electric motor, power consumption increases and engine fuel efficiency worsens.Furthermore, for drive control of the electric motor, pressure sensors, for example, are required. Since various sensors such as a temperature sensor and an air volume sensor and an electrical control circuit are required, the device becomes complicated and its manufacturing cost increases.

Therefore, the applicant of the present invention has previously proposed a variable capacity vane type rotary compressor (Japanese Patent Application No. 61-2010) in order to solve the above-mentioned problems.
No. 25563).

In the device according to this earlier application, the discharge pressure of the compressor is controlled by a control valve and supplied as working pressure to the actuator cylinder, and in the actuator cylinder, the working pressure is applied to the piston stopped at the end of the stroke due to the biasing force of the spring. The discharge amount of the compressor is varied by pressing against the force and rotating the movable plate.

(Problem to be Solved by the Invention) By the way, in the device according to the prior application, the piston of the actuator cylinder is biased toward the stroke end of the cylinder by a spring, so for example, compression When the machine stops, the movable plate stops at the position where the bypass port is fully closed or fully open. In other words, the compressor stops when the discharge amount is at its maximum or minimum. Therefore, when the discharge amount is at its maximum and the engine stops, the starting torque increases. Further, if the discharge amount is stopped at the minimum, the operating pressure to drive the cylinder cannot be obtained, and the minimum displacement is increased to obtain the operating pressure that can drive the cylinder. As a result, it is difficult to reduce the minimum capacity, the variable range of discharge capacity is small, and the compressor must be started or stopped depending on the air conditioning conditions, and as a result, engine load fluctuations are unavoidable at startup. It is expected that this will impair the driving feeling of the vehicle, and it is desirable to improve this point.

(Objective of the Invention) Therefore, the present invention makes the piston of the actuator cylinder stand still at an intermediate position of the stroke by a biasing means, and drives the actuator cylinder by an intermediate pressure obtained by controlling the suction pressure, the discharge pressure, and the discharge pressure. The purpose of this is to start the compressor from an intermediate discharge amount, widen the variable range of the discharge amount, reduce engine load fluctuations caused by compressor operation, and improve the driving feeling of the vehicle. There is.

(Means for Solving the Problems) In order to achieve the above object, the variable capacity vane type rotary compressor according to the present invention includes a cam ring with a cam surface formed on the inner periphery and a plurality of suction ports. A front plate provided on the front side, a rear plate that seals the opening on the rear side of the cam ring, a rotor located between the front plate and the rear plate and rotatably housed in the cam ring, and the cam ring. It houses a plurality of working chambers formed between the rotor, a plurality of vanes that are retractably fitted into the rotor and whose tips make sliding contact with the cam surface, and the cam ring, front plate, rear plate, rotor, and vanes. A cylindrical housing with a bottom, a head cover that seals the open end of the housing, a suction chamber defined by the cover and the front plate, and a suction chamber formed in the cam ring and connected to the suction chamber through the suction port of the front plate. a plurality of suction boats opening on the cam surface and formed on the front plate so as to communicate with each other and cut off communication with the working chamber when the volume of the working chamber divided by the vane reaches a maximum; a bypass port that opens into the working chamber along the cam surface and communicates with the suction chamber; a movable plate that is rotatably provided between the front plate and the cam ring and has a bypass opening that adjusts the opening degree of the bypass port; It is equipped with an actuator that rotates a movable plate, and a control valve that supplies suction pressure or discharge pressure of the compressor to the actuator to operate the actuator, and changes the discharge amount of the compressor by driving the control valve. In the variable capacity vane type rotary compressor, the actuator has a cylinder and a piston that is slidably inserted into the cylinder and rotates the movable plate, and the cylinder is moved by the piston into a first cylinder chamber and a second cylinder chamber. The intermediate pressure obtained by controlling the discharge pressure is supplied to the first cylinder chamber, and the discharge pressure or suction pressure of the compressor is supplied to the second cylinder chamber by a control valve. A first biasing means and a second biasing means are interposed in the chamber and the second cylinder chamber, respectively, so that when the compressor is stopped, the piston is stopped at an intermediate position of the stroke, and the compressor is moved to an intermediate position other than the maximum or minimum stroke. It is started from a discharge amount of .

(Function) In the present invention, the compressor is started from an intermediate discharge amount to reduce the starting torque, and the minimum discharge amount is reduced and the variable range of the discharge amount is widened, so that the compressor is repeatedly operated and stopped. It is possible to maintain the discharge amount according to the load of the air conditioner without causing any problems. Therefore, sudden load fluctuations in the engine due to repeated starting and stopping of the compressor are reduced, and the driving feeling of the vehicle is improved.

(Example) Hereinafter, the present invention will be explained based on the drawings.

1 to 4 are diagrams showing one embodiment of the present invention.

In FIG. 1.2, 1 is a cylindrical cam ring, and a cam surface 1a having a substantially elliptical cross section is formed on the inner periphery. A front plate 2 and a rear plate 3 are attached to both the front side (left side in FIG. 1) and rear side (right side in FIG. 1) of the cam ring 1, and the rear plate 3 is attached to the rear side opening of the cam ring 1. The ends are sealed. A cylindrical rotor 4 is rotatably housed in the cam ring 1 between the front plate 2 and the rear plate 3.
A plurality of vanes 5 are fitted into and retracted from the cam surface 1a so that their tips come into sliding contact with the cam surface 1a. the cam ring 1;
The front plate 2, rear plate 3, rotor 4, and vane 5 are housed in a bottomed cylindrical housing 6,
A head cover 7 for sealing the opening is attached to the front opening end (left end in FIG. 1) of the housing 6 by bolts (not shown). A pair of working chambers 8 are formed between the cam ring 1 and the rotor 4, and communicate with a pair of suction boats 9 that are open on the cam surface 1a. A discharge chamber 10 inside the housing 6 and the working chamber 8 communicate with each other through a discharge boat and a discharge valve (not shown) formed in the cam ring 1 . Reference numeral 11 denotes a suction chamber defined by the front plate 2 and the head cover 7, into which refrigerant gas is introduced through an inlet 12 provided in the head cover 7, and a pair of suction ports 13 formed in the front plate 2.
Refrigerant gas is supplied to the working chamber 8 via the suction boat 9 formed in the cam ring 1 (see FIG. 2) and the cam ring 1, respectively.

Reference numeral 14 designates a pair of arc-shaped bypass ports formed on the front plate 2, and as shown in FIG.
an open end 11 along which the suction boat 9 opens into the working chamber 8;
Working chamber 8 and suction chamber 11 along cam surface 1a from near a
are communicating. A disk-shaped movable plate 15 is interposed between the front plate 2, the cam ring 1, and the rotor 4, and the movable plate 15 is connected to the ring member 2 of the front plate 2.
It is accommodated in the inner periphery 2b of a. The movable plate 15 is the rotor 4
A bypass port 14 is rotatably supported around the axis of the bypass port 14, and a pair of fan-shaped bypass openings 16 are cut out in the outer periphery 15a, and the working chamber 8 and the suction chamber 11 are communicated with each other by rotation of the movable plate 15. The opening degree of the opening can be adjusted. That is, in FIG. 2, when the movable plate 15 rotates clockwise and the opening degree of the bypass port 14 increases, the amount of bypass from the working chamber 8 to the suction chamber 11 increases, so the discharge amount of the compressor decreases. However, when the movable plate 18 rotates counterclockwise and the opening degree of the bypass port 14 becomes smaller, the discharge amount of the compressor increases.

On the other hand, 17 is an actuator provided on the head cover 7, and as shown in FIG.
It has 8. A piston 19 is slidably provided in the cylinder 18, and the piston 19 causes the cylinder 1 to move.
8 is defined into a first cylinder chamber 20 and a second cylinder chamber 21. An intermediate pressure passage 24 formed in the head cover 7 is connected to the first cylinder chamber 20 , and the intermediate pressure of the compressor is introduced into the first cylinder chamber 20 through the intermediate pressure passage 24 . Note that the intermediate pressure is the pressure of lubricating oil that is sent from the discharge chamber 10 through the throttle formed in the rear plate 3 to the back of the vane 5 and urges the vane 5 toward the cam surface 1a, as shown in FIG. As shown in , the pressure is lower than the discharge pressure and higher than the suction pressure.

Further, a coil spring (first biasing means) 22 and a coil spring (second biasing means) 23 are provided in the first cylinder chamber 20 and the second cylinder chamber 21, and the piston 19 is connected to the coil spring 22. The spring force of the coil spring 23 and the pressure from the control valve 29 bias it toward the right in FIG. 3, and the spring force of the coil spring 23 and the pressure from the control valve 29 bias it toward the left. On the other hand, when the compressor stops, the suction pressure, discharge pressure, and intermediate pressure gradually become equal due to internal leakage, so only the spring forces of the coil springs 22 and 23 act on the piston 19 in opposition. I will do it. The spring force of each coil spring 22, 23 is set so that the piston 19 stops at an intermediate position in the cylinder 18 in this state. A piston loft 19a is provided on the first cylinder chamber 20 side of the piston 19, and the piston rod 19
At the tip of a, one end of the L-shaped connecting plate 25 is attached to a fixing member 26.
installed by. The other end of the connecting plate 25 is the pin 2
It is connected to the movable plate 15 via 7.

The open end of the second cylinder chamber 21 is sealed with a stopper 28, and the second cylinder chamber 21 communicates with the control valve 29 via a control pressure passage 30. As shown in FIG. 1, the control valve 29 has a suction pressure introduction passage 3.
The suction pressure and discharge pressure of the compressor are introduced through the compressor 1 and the discharge pressure introduction passage 32, and the control valve 29 switches the suction pressure or the discharge pressure to the control pressure through the control pressure passage 30 according to the operating state of the compressor. and is supplied to the second cylinder chamber 21.

The differential pressure between the operating pressure and the intermediate pressure causes the piston 19 to move in the axial direction of the cylinder 18, and the movable plate 18 to rotate via the connecting plate 25 and the bottle 27, thereby controlling the discharge amount of the compressor.

Next, the effect will be explained.

When the compressor is started, there is no differential pressure between the suction pressure and the discharge pressure yet, so the intermediate pressure acting on the actuator 17 is equal to the control pressure, and the piston 19 is not in a state to move. Therefore, the piston 19 is held at an intermediate position in the stroke of the piston 19 where the coil springs 22 and 23 are balanced. That is, as shown in FIG. 2.4, the bypass port 14 has an intermediate opening degree, and the compressor is started from an intermediate discharge amount state. When the rotating shaft of the rotor 4 is driven by the engine of the vehicle and the rotor 4 rotates clockwise in FIG. 2, approximately half of the refrigerant gas at the maximum capacity is sucked into the compressor, and the refrigerant gas is compressed The discharge chamber 1 becomes high pressure and high temperature.
0, gradually increases the pressure in the chamber 10, and is supplied to an air conditioner (not shown).

After the compressor is started, the intermediate pressure supplied to the first cylinder chamber 20 of the actuator cylinder 17 increases (becomes high) as the discharge pressure increases.On the other hand, the second cylinder chamber 21 receives suction pressure or The operating pressure of the discharge pressure is supplied by the control valve 29. For example, when the load of the air conditioner becomes large, the suction pressure lower than the intermediate pressure is supplied to the second cylinder chamber 21 by the control valve 29, and the piston 19 3, the opening degree of the bypass port 14 becomes smaller, the bypass amount of refrigerant decreases, and the discharge capacity of the compressor increases.On the other hand, when the load of the air conditioner becomes smaller, the second cylinder chamber 21 A discharge pressure higher than the intermediate pressure is supplied by the control valve 29, the piston 19 is pushed to the left in FIG. Discharge volume decreases.

Further, when the compressor is stopped, when the rotor 4 stops, the pressure in the discharge chamber 10 decreases, and the pressure in the discharge chamber 10 and the suction chamber 1 decrease.
1 pressure and intermediate pressure will be the same. That is, since no high discharge pressure is generated by the compressor, empty 1! The pressure in the equipment and piping inside the machine is constant, and the pressures in the discharge chamber 10 and the suction chamber 11 are also the same. Then, the pressures within the first cylinder chamber 20 and the second cylinder chamber 21 of the actuator 17 are balanced. Therefore, the piston 19 remains at an intermediate position where the coil springs 22 and 23 are balanced. Therefore, the next time the compressor is started, it is possible to start the compressor from an intermediate position, that is, from an intermediate discharge amount of the compressor.

In this way, in the variable capacity vane type rotary compressor of this embodiment, since the compressor can be started from an intermediate discharge rate state, the starting torque of the compressor can be reduced and sudden engine load fluctuations can be reduced. I can do it.

In addition, since the compressor can be started from an intermediate discharge rate,
Since the minimum discharge amount can be reduced and the variable range of the discharge amount can be widened, the discharge amount can be obtained in accordance with the load of the air conditioner without turning the compressor clutch ON-OFF. Therefore, sudden load fluctuations in the engine can be reduced, and the driving feeling of the vehicle can be improved.

(Effects) According to the present invention, the piston of the actuator is stopped at the intermediate position of the stroke by the biasing means, and the actuator is driven by the control pressure of the suction pressure or the discharge pressure and the intermediate pressure between the discharge pressure and the suction pressure. As a result, the compressor can be started from an intermediate discharge amount and the variable range of the discharge amount can be widened, reducing engine load fluctuations caused by compressor operation and improving the driving feeling of the vehicle. can be done.

[Brief explanation of the drawing]

1 to 5 are diagrams showing an embodiment of a variable capacity vane type rotary compressor according to the present invention, and FIG. 1 is a front sectional view thereof;
Figure 2 is a sectional view taken along line nn' in Figure 1, Figure 3 is a sectional view taken along line m-m' in Figure 2, and Figure 4 is rt/-IV' in Figure 1.
The cross-sectional view, FIG. 5, is a diagram for explaining intermediate pressure. 1...Cam ring, 1a...Cam surface, 2...Front plate, 3...Rear plate, 4...Rotor, 5. ... Vane, 6 ... Housing, 7 ... Head cover, 8 ... Working chamber, 9 ... Suction port, 11 ... ... Suction chamber, 14 ... Bypass port, 15 ... Movable plate, 16 ... Bypass opening, 17 ... Actuator, 18 ... ...Cylinder, 19...Piston, 20...First cylinder chamber, 21...Second cylinder chamber, 22...Coil spring (first attached) force),
23... Coil spring (second biasing means),
29...Control valve.

Claims (1)

[Claims] A cam ring with a cam surface formed on its inner periphery, a front plate provided on the front side of the cam ring with multiple intake ports, a rear plate that seals the opening on the rear side of the cam ring, a front plate and A rotor is located between the rear plates and is rotatably housed in a cam ring, a plurality of working chambers are formed between the cam ring and the rotor, and a cam surface is fitted into the rotor so that it can be freely retracted from the cam ring. A cylindrical housing with a bottom that accommodates the cam ring, front plate, rear plate, rotor, and vanes; a head cover that seals the open end of the housing; and the head cover and the front plate. The suction chamber formed in the cam ring communicates with the suction chamber through the suction port on the front plate, and when the volume of the working chamber divided by the vane reaches its maximum, communication with the working chamber is cut off. A bypass port is formed on the front plate that opens into the working chamber along the cam surface and communicates with the suction chamber, and is rotatable between the front plate and the cam ring. a movable plate having a bypass opening that adjusts the opening degree of the bypass port, an actuator that rotates the movable plate, and a control valve that supplies suction pressure or discharge pressure of the compressor to the actuator to operate the actuator. In a variable capacity vane rotary compressor that changes the discharge amount of the compressor by driving the control valve, the actuator is slidably fitted into a cylinder, and the movable plate is slidably inserted into the cylinder. It has a piston that rotates the
The cylinder is defined by a piston into a first cylinder chamber and a second cylinder chamber, and the first cylinder chamber is supplied with an intermediate pressure obtained by controlling the discharge pressure, and the second cylinder chamber is supplied with an intermediate pressure obtained by controlling the discharge pressure of the compressor by a control valve. In addition to supplying pressure or suction pressure, a first urging means and a second urging means are interposed in the first cylinder chamber and the second cylinder chamber, respectively, so that the piston is stopped at an intermediate position of the stroke when the compressor is stopped. A variable capacity vane type rotary compressor, characterized in that the compressor is started from an intermediate discharge amount state other than the maximum or minimum.