JP2973226B2 - Variable displacement gas compressor - Google Patents

Description

The present invention relates to a variable displacement gas compressor used for car air conditioners and the like.

<< Conventional Technology >> Conventionally, this type of variable displacement gas compressor has a compressor body 1 as shown in FIG. 3, and the compressor body 1 is provided at both ends of an inner elliptical cylindrical cylinder 2. Attach the front side block and rear side block (not shown),
A cylinder chamber 3 is formed by these three members, and a rotor 4 is rotatably disposed in the cylinder chamber 3.

Further, five vanes 5 are radially fitted to the rotor 4 and fitted closely to the inner wall of the cylinder chamber 3 so that the inside of the cylinder chamber 3 has five compression working chambers. Are divided into 3a, 3a,... And rotate together with the rotor 4 to compress the refrigerant gas in the compression working chamber 3a, while the compressed refrigerant gas is indicated by a dotted arrow in the figure. Is discharged to the outside of the compression working chamber 3a, and the discharge pressure Pd acts on an oil reservoir (not shown) of lubricating oil.

Further, the capacity of the compression working chamber 3a is variable according to the rotation angle of the rotatable control plate 6, and according to the control plate 6, the compression work chamber 3a is compressed from the suction chamber side (not shown) through the recesses 6a, 6a. While the refrigerant gas is supplied to the working chamber 3a, the compression working chamber 3a is turned into a small capacity by turning the control plate 6 clockwise, and the compression working chamber 3a is turned into a large capacity by turning counterclockwise. It is configured to be.

By the way, the drive mechanism for rotating the control plate 6 as described above is provided with a drive piston 8 which can move forward and backward in a cylinder chamber 7 as shown in FIG. 9 is a drive pin 10 of the control plate 6
Is loosely fitted, so that the rotation of the control plate 6 continues to move forward and backward of the drive piston 8.

Further, a spring 11 is provided on the drive piston tip 8a side, and the spring 11 constantly biases the drive piston 8 toward the left side so that the control plate 6 which is continuously connected as described above is actuated. The compression working chamber is configured to be set at a position where the compression working chamber has the minimum capacity.

Further, the suction pressure Ps of the suction chamber 12 acts on the drive piston tip 8a side, while the control hydraulic chamber is controlled on the drive piston rear end 8b side.
The control hydraulic chamber 13 is configured such that oil at a discharge pressure Pd is supplied from an oil reservoir (not shown) via a fixed shiver 14.

The control hydraulic chamber 13 is connected to the intake chamber via an oil discharge passage 15.
A valve 16 is provided in the middle of the oil discharge passage 15, and the valve 16 controls the amount of oil flowing from the control hydraulic chamber 13 to the intake chamber 12 via the oil discharge passage 15. The valve body 16 is attached to the movable end 17a of the bellows 17 on which the suction pressure Ps acts, and the bellows 17 expands and contracts in accordance with a change in the suction pressure Ps. Is configured to open and close.

Therefore, according to the drive mechanism as described above, the control plate 6 is set at the position where the compression working chamber has the minimum capacity before the compressor is started, and when the compressor is started thereafter, the oil of the discharge pressure Pd is discharged. Hydraulic chamber controlled via fixed shivering 14
13, the driving piston 8 moves rightward against the urging force of the spring 11 and the suction pressure Ps. As a result, the control plate 6 rotates counterclockwise, the compression working chamber has the maximum capacity, and the extruder starts up.

The compressor that has started up as described above is subjected to a control operation next. When the suction pressure Ps of the intake chamber 12 decreases due to, for example, a high-speed operation of the compressor, the bellows 17 extends. Then, the valve element 16 moves so as to open the oil discharge passage 15, and the oil in the control hydraulic chamber 13 flows through the oil discharge passage 15 to the intake chamber 12 side. As a result, the control plate 6 rotates clockwise to reduce the capacity of the compression working chamber,
It is configured to increase the suction pressure Ps in 12.

<< Problems to be Solved by the Invention >> However, in such a variable displacement gas compressor, in order to smoothly operate the drive piston 8,
Since the outer periphery of the drive piston 8 is not sealed at all, the oil in the control pressure chamber 13 is supplied from the outer periphery of the drive piston 8 to the intake chamber.
Leakage to the 12 side is inevitable, and a large amount of oil must be supplied to the control pressure chamber 13 so as to compensate for this leakage amount.

Further, since the compression working chamber 3a is set to the minimum capacity before the compressor is started, it is necessary to rotate the control plate 6 so that the compression working chamber 3a has the maximum capacity in a short time immediately after the start. For this reason, the supply amount of the oil that is pressure-fed to the control hydraulic chamber 13 via the fixed shivering 14 must be sufficiently increased.

Therefore, conventionally, it is unavoidable that the supply amount of the oil increases due to the above-described reasons. Accordingly, in order to enhance the rotational response of the control plate 6 during the control operation of the compressor, the supply amount of the oil is increased. It is necessary to set a sufficiently large amount of oil to be drained toward the intake chamber 12 via the oil discharge path 15 in accordance with the amount.

Therefore, during the control operation of the compressor, a large amount of oil flows into the intake chamber 12 side, so that it is difficult to secure the oil in the oil sump, thereby reducing the lubricating action of the rotating system such as the rotor 4. There was a point.

Naturally, the oil in the control hydraulic chamber 13 is supplied via the fixed swirler 14, so that immediately after the start of the compressor, the rising time until the compression working chamber 3a shifts to the maximum capacity is delayed. There was a problem.

<< Means for Solving the Problems >> The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the amount of oil flowing to the intake chamber side during the control operation of the compressor, In order to achieve the above object, the present invention compresses refrigerant gas in an intake chamber by a vane in a compression work chamber immediately after the compressor is started. And a compressor body that discharges outside the compression working chamber and applies the discharge pressure to a lubricating oil sump,
A variable displacement gas compressor having at least a rotatable control plate that varies the capacity of the compression working chamber according to a rotation angle and a drive mechanism that rotates the control plate, wherein the drive mechanism includes a control plate. A drive piston capable of moving forward and backward in the control cylinder chamber, a control hydraulic chamber facing the rear end of the drive piston, and an oil having one end opened to the control hydraulic chamber and the other end opened to the oil sump. A variable path provided in the supply path and in the middle of the oil supply path, wherein the oil supply path before the start of the compressor is fully opened and the oil supply path is variably throttled according to the operation state of the compressor during operation of the compressor. And a fixed displacement provided in an oil discharge path for discharging oil from the control hydraulic chamber to the intake chamber side, and oil in a sump is supplied to the control hydraulic chamber via a variable displacement section by a discharge pressure. The oil in the control hydraulic chamber Discharged to the intake chamber side via Shibori, and the amount of oil in the control hydraulic chamber is increased or decreased according to the throttle state of the variable Shibori section, so that the drive piston moves forward and backward to change the capacity of the compression work chamber. It is characterized by.

<< Operation >> According to the present invention, the oil at the discharge pressure is supplied from the oil sump to the control hydraulic chamber via the variable sliver in the oil supply path, while the oil in the control hydraulic chamber is directed to the intake chamber via the fixed sliver. Acts to be discharged.

<< Embodiment >> Hereinafter, an embodiment of a variable displacement gas compressor according to the present invention will be described in detail with reference to FIGS. 1 and 2. FIG.

The capacity of the compressor body and the compression working chamber is varied according to the rotation angle of the control plate, and the basic configuration of the drive mechanism for rotating the control plate is the same as the conventional one. The same reference numerals are given and the detailed description is omitted.

As shown in FIG. 1, the drive mechanism of the control plate in this variable displacement type gas compressor has one end 18a of an oil supply passage 18 opened in a control hydraulic chamber 13 facing the rear end 8b of the drive piston. According to the passage 18, the other end (not shown) is opened to an oil reservoir on which the discharge pressure Pd acts, and the oil of the discharge pressure Pd is directly pressure-fed to the control hydraulic chamber 13 from the oil reservoir.

Further, a variable sliver section 19 is provided in the middle of the oil supply path 18, and the variable sliver section 19 is provided with a lot-shaped valve body 20 which can be protruded and retracted into the oil supply path 18. 20
One end of the bellows 21 is fixed to the movable end 21a of the bellows 21. According to the bellows 21, the one end of the bellows 21 is attached to the inner wall of the chamber chamber 22 where the suction pressure Ps of the suction chamber 12 acts, and is configured to expand and contract in accordance with the fluctuation of the suction pressure Ps. Have been.

That is, in the variable shibo section 19 as described above,
The valve body 20 variably throttles the oil supply path 18 according to the operation state of the compressor. Before the compressor starts, the bellows 21 contracts and the valve body 20 opens the oil supply path 18 fully. (See FIG. 2A). On the other hand, in the maximum capacity operation of the compressor described later, the bellows 21 is extended,
20 is set to throttle the oil supply passage 18 (FIG. 2 (b)
reference). Further, during the control operation of the compressor described later, the bellows 21 is further extended, and the valve element 20 is set so as to completely close the oil supply passage 18 (see FIG. 3 (c)).

Further, the gap 23 between the drive piston 8 and the control cylinder 7 is configured to also serve as a discharge path for constantly draining the oil in the control hydraulic chamber 13 toward the intake chamber 12 and also as a function of a fixed displacement.

Next, the operation of the variable displacement gas compressor configured as described above will be described in detail with reference to FIGS. 1 and 2.

Immediately after the start of the compressor, as shown in FIG. 2 (a), since the valve element 19 fully opens the oil supply passage 18, the discharge pressure Pd is supplied to the control hydraulic chamber 13 via the oil supply passage 18. The oil is directly pressure-fed, and the pressure in the control hydraulic chamber 13 rapidly rises. As a result, the piston 8 quickly moves to the right to rotate the control plate 6 in the counterclockwise direction, the compression working chamber reaches its maximum capacity in a short time, and the gas compressor starts up.

On the other hand, when the suction pressure Ps of the suction chamber 12 decreases in the process of the compression working chamber having the maximum capacity as described above, the bellows 21 expands as shown in FIG. The compression work chamber is set to the maximum capacity while the oil in the oil supply path 18 is being throttled by the valve body 20, and the compressor is operated at the maximum capacity in this state.

If the suction pressure Ps of the intake chamber further decreases from the maximum capacity operation as described above due to, for example, a high-speed operation of the compressor, a control operation as shown in FIG. 2C is performed. That is, according to the control operation, the bellows 21 further extends, the oil supply passage 18 is fully closed, and as a result, the oil pumped into the control hydraulic chamber 13 is shut off, while the control hydraulic chamber 13
The oil in the gap 23 between the drive piston 8 and the control cylinder 7
(Fixed Swirl) and then to the suction chamber 12 side,
The pressure in 13 decreases. As a result, the piston 8 moves to the left to rotate the control plate 6 clockwise, so that the capacity of the compression working chamber decreases and the suction pressure Ps of the suction chamber 12 increases.

That is, according to the operating state of the compressor, the variable swivel section fully opens the oil supply path before starting the compressor, and variably restricts the oil supply path in accordance with the operating state of the compressor. The position of the control plate and the control plate engaged with is controlled to change the capacity of the compression working chamber.

Therefore, according to the above embodiment, the oil in the oil sump is supplied to the control hydraulic chamber via the variable sliver section by the discharge pressure, and the oil in the control hydraulic chamber is discharged to the intake chamber side via the fixed sliver. Since the drive piston is moved forward and backward by changing the amount of oil in the control hydraulic chamber in accordance with the throttle state of the variable shift section, and the capacity of the compression working chamber is changed, the oil supplied to the control hydraulic chamber is controlled. Is throttled by the valve element of the variable shivering part, and the absolute amount of supplied oil is smaller than before, so that it is easy to secure the oil in the oil reservoir, and as a result, the lubricating action of the rotating system such as the rotor 4 is reduced. Can be maintained.

Further, in the above embodiment, immediately after the start of the compressor, the variable displacement is set to the fully open state, so that the oil at the discharge pressure is directly sent to the control hydraulic chamber via the oil supply path, thereby controlling the control plate. Shifts to the maximum capacity in a short time, so that the time required for starting the compressor is short.

<< Effect of the Invention >> In the variable displacement gas compressor according to the present invention, the oil in the oil sump is supplied to the control hydraulic chamber via the variable swivel section provided in the middle of the oil supply path as described above, while the control hydraulic pressure is controlled. Because the oil in the chamber is configured to be drained to the intake chamber side via the fixed swirl,
The oil supplied to the control hydraulic chamber is throttled by the variable swirl part, and the absolute amount of the supplied oil is smaller than before, so it is easy to secure the oil in the oil reservoir, and as a result, the rotor, etc. The lubricating action of the rotating system can be maintained.

Also, since the above-mentioned variable rotation is set so that the oil supply path is fully opened before the compressor starts, immediately after the compressor starts, the oil at the discharge pressure is directly pumped to the control hydraulic chamber via the oil supply path. As a result, the control plate quickly shifts to the maximum capacity, so that the compressor starts up quickly.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a main part of a variable displacement gas compressor according to the present invention, FIGS. 2 (a), 2 (b) and 2 (c) are explanatory views for explaining the operation of the compressor, and FIG. FIG. 4 is a sectional view of the compressor, and FIG. 4 is an explanatory view showing a main part of a conventional compressor. DESCRIPTION OF SYMBOLS 1 ... Compressor main body 3a ... Compression working chamber 5 ... Vane 6 ... Control plate 8 ... Driving piston 12 ... Intake chamber 13 ... Control hydraulic chamber 18 ... Oil supply passage 19 ... ……gap

Claims (1)

(57) [Claims] 1. A compressor body for compressing refrigerant gas in an intake chamber by a vane in a compression working chamber and discharging the compressed gas to the outside of the compression working chamber, and applying the discharge pressure to an oil sump of lubricating oil; A variable controllable gas compressor having at least a rotatable control plate that varies the angle of rotation according to a rotation angle, and a drive mechanism that rotates the control plate, wherein the drive mechanism engages with the control plate to control A drive piston capable of moving forward and backward in the cylinder chamber, a control hydraulic chamber facing the rear end of the drive piston, an oil supply path having one end opened to the control hydraulic chamber and the other end opened to the oil reservoir, and the oil A variable sliver section that is provided in the middle of the supply path, fully opens the oil supply path before starting the compressor, and variably restricts the oil supply path according to the operation state of the compressor during operation of the compressor; Chamber oil intake chamber And a fixed sump provided in an oil discharge path for discharging oil to the control hydraulic chamber via a variable sump section by a discharge pressure and oil in the control sump via a fixed sump. It is discharged to the intake chamber side, and the amount of oil in the control hydraulic chamber is increased or decreased according to the throttle state of the variable swivel part, so that the drive piston moves forward and backward to change the capacity of the compression work chamber. Displacement type gas compressor.