JPH0587049A - Capacity control device of variable capacity oscillating plate type compressor - Google Patents

Abstract

PURPOSE:To suppress a torque variation and to avoid a liquid contraction by providing a capacity control valve with a relatively large opening area in one side of plural passages communicating a crankcase and a suction chamber, and cutting off the passage when the pressure in the crankcase is made lower than a specific value. CONSTITUTION:In a communicating passage 16 between a crankcase 6 housing an oscillating plate 50 installed to a rotary shaft 7, and a suction chamber 15, a valve chamber 18 is provided. And a control valve 19 to open and close the communicating passage 16 according to the suction air pressure is provided to the valve chamber 18, and thereby the pressure in the crankcase 6 is regulated to convert the inclination of the oscillating plate 50. In such a constitution, the second communicating passage 39 to communicate the both chambers 6 and 15 is added, and a capacity control valve 27 which is closed when the pressure in the crankcase 6 is lowered less than a specific value is provided therein. And the opening area of the capacity control valve 27 is made larger than that of the control valve 19. Furthermore, an orifice 29 is provided at the discharge side end of the second communicating passage 39 to throttle the passage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacity control device for a variable displacement type oscillating plate compressor, and more particularly to a capacity control device capable of preventing a sudden increase in capacity when the oscillating plate compressor is started.

[0002]

2. Description of the Related Art As a conventional variable displacement type oscillating plate type compressor, a communication passage connecting an intake chamber and a crank chamber accommodating the oscillating plate is provided, and the suction pressure is below a predetermined value in the middle of the communication passage. A control valve is provided to close the communication passage when the intake pressure exceeds a predetermined value, and to open the communication passage when the suction pressure exceeds a predetermined value.The control valve adjusts the pressure in the crank chamber to change the inclination angle of the oscillating plate. There is one (JP-A-62-2)
94782).

[0003]

In the conventional variable displacement type oscillating plate compressor, the inclination angle of the oscillating plate is small due to the urging force of the spring mounted on the shaft when the compressor is stopped. Since the suction pressure is high, the control valve opens, the rocking plate quickly falls to the full stroke side, and the capacity increases. Although the torque is small at the moment of starting the engine, when the heat load is high, the engine is immediately in full operation, causing a rapid torque increase.In the idling state of the engine, the idling rotation becomes unstable due to load fluctuations, and thus the engine. May cause stalls. Further, since the torque increases rapidly at the time of starting the compressor, noise, abnormal wear and damage due to impact occur. Further, when the refrigerant is in a liquid state and is operated in a full stroke (so-called liquid compression operation), the discharge pressure of 14 to ²⁰ kg / cm ² G normally rises to 100 to 140 kg / cm ² G.

The present invention has been made in view of the above circumstances, and its object is to suppress torque fluctuation at the time of starting the compressor, reduce the load on the engine, avoid liquid compression operation, and start at the time of starting. It is an object of the present invention to provide a capacity control device for a variable capacity oscillating plate compressor that can prevent noise and abnormal wear.

[0005]

In order to solve the above-mentioned problems, the present invention relates to a shaft rotatably supported, a rocking plate mounted on the shaft so as to be rockable, an intake chamber and the rocking motion. A first communication passage that connects the crank chamber in which the plate is housed is provided, and a valve chamber is provided in the middle of the communication passage. When the suction pressure is equal to or lower than a predetermined value, the first communication passage is closed to reduce the suction pressure. A control valve that opens the first communication passage when the value is equal to or more than a predetermined value is provided in the valve chamber, and the control valve adjusts the pressure in the crank chamber to change the inclination angle of the oscillating plate. In a displacement control device for a variable displacement type oscillating plate compressor, a second communication passage connecting a discharge chamber and the crank chamber is provided, and the second communication passage is closed when the pressure in the crank chamber becomes a predetermined value or less. In front of capacity control valve Disposed in the middle of the second communication passage, the opening area of the capacity control valve is larger than the opening area of the control valve, targeted discharge chamber-side end portion of the second communicating path.

[0006]

[Action] Immediately after the start of the compressor, the control valve opens due to the high suction pressure, and the refrigerant gas in the crank chamber escapes to the suction chamber through the communication passage, but the opening area of the capacity control valve is larger than that of the control valve. The amount of high-pressure refrigerant gas introduced from the discharge chamber to the crank chamber through the second communication passage is larger than the amount of refrigerant gas escaping from the crank chamber to the suction chamber, and in the low rotation speed range immediately after starting the crank chamber, Pressure does not decrease, but gradually increases,
The oscillating plate maintains a small capacity angle and small capacity operation is performed. After that, when the rotation of the shaft gradually increases, the throttle function at the end of the second communication passage on the discharge chamber side has a large effect, and the amount of refrigerant gas that escapes from the crank chamber to the suction chamber is introduced from the discharge chamber to the crank chamber. The amount of high-pressure refrigerant gas is increased, and as a result, the pressure in the crank chamber decreases, the displacement control valve also closes, the tilt angle of the oscillating plate increases, and the displacement gradually increases.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a vertical cross-sectional view of a variable displacement type oscillating plate compressor having a displacement control device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 is a compressor housing, and housing 1 is a cylinder. A block 2, a rear head 4 airtightly attached to one end surface (left end surface in the drawing) of the cylinder block 2 via a valve plate 3, and a rear head 4 airtightly attached to the other end surface (right end surface in the drawing) of the cylinder block 2. And a front head 5. Inside the housing 1, a crank chamber 6 is defined by an end surface of the cylinder block 2 on the front head 5 side and an inner peripheral surface and an inner end surface of the front head 5. In the cylinder block 2,
A plurality of cylinders 8 are arranged at predetermined intervals in the circumferential direction with the shaft 7 arranged substantially on the center line of the housing 1 as a center and with its axis parallel to that of the shaft 7. A piston 9 is slidably fitted in each of the cylinders 8.

A discharge port (not shown) for discharging the compressed refrigerant gas is formed in one end surface of the rear head 4. The discharge chamber 1 is provided at a substantially central portion inside the rear head 4.
0 is formed, and the discharge chamber 10 is divided into the first chamber 1 by the partition wall 11.
0 ₁ is partitioned into a second chamber 10 ₂ through the throttle hole 11a bored in the partition wall 11, these first chamber 10 ₁ and the second chamber 10 ₂ is communicated with each other. The valve plate 3 is provided with a discharge port 3a which communicates with the cylinder 8 and the first chamber 10 _1.
, The first chamber 10 _1, sequentially through the throttle hole 11a and the second chamber 10 _2, communicates with the discharge port. The discharge port 3a is opened and closed by a discharge valve 12, and the discharge valve 12 is fixed to a rear head 4 side of the valve plate 3 by a bolt 14 together with a valve stopper 30, and the bolt 14 is provided through a hole 3b of the valve plate 3 and the above-mentioned structure. It is screwed into the small diameter hole 22c of the cylinder block 2. The bolt 14 is provided with a high-pressure guide path 20 along the axial direction, and an orifice 20 having a metering function is provided in the middle of the high-pressure guide path 20.
a is provided to throttle the flow rate of the refrigerant gas guided from the discharge chamber 10 to the radial bearing 13 side. Discharge chamber 1
A suction chamber 15 is formed on the outer peripheral side of 0, and the suction chamber 15 is communicated with the cylinder 8 via a suction port 3c formed in the valve plate 3. The suction port 3c is opened and closed by a suction valve 31, and the suction valve 31 is attached to the valve plate 3 on the cylinder block 2 side.

The suction chamber 15 is connected to an outlet of an evaporator of an air conditioner (not shown) through a suction port (not shown), and the discharge chamber 10 is connected to an inlet of a condenser (not shown) via the discharge port. ..

A large-diameter hole 2 is formed in the substantially central portion of the cylinder block 2 from the front head 5 side toward the rear head 4.
A communication hole composed of 2a, a medium diameter hole 22b, and a small diameter hole 22c is sequentially formed along the shaft axis. A radial bearing 13 is provided in the medium diameter hole 22b of the communication hole, and a thrust bearing 17 is provided in the large diameter hole 22a.

Further, the cylinder block 2 has a communication passage 16 for communicating the suction chamber 15 and the crank chamber 6,
Communication passage 3 for communicating the discharge chamber 10 and the crank chamber 6
9 are provided respectively. A valve chamber 18 is provided in the middle of the communication passage 16, and a control valve 19 is accommodated in the valve chamber 18. A capacity control valve 27 is provided in the middle of the communication passage 39. First
The communication passage is composed of a communication passage 16 and a hole 28 formed in the valve plate 3. The second communication passage is the communication passage 3
9 and an orifice 29 bored in the valve plate 3. The opening area of the capacity control valve 27 is larger than the opening area of the control valve 19.

The control valve 19 includes a valve body 2
1 and a valve case 22 accommodating the valve body 21. The valve body 21 includes a valve body 21a, a low pressure side bellows portion 21b that expands and contracts according to the suction pressure Ps, and a high pressure side bellows portion 21c that expands and contracts according to the discharge pressure Pd. The valve case 22 is a cylindrical case, and the tip end surface of the valve case 22 has a relief hole 2 for letting the valve body 21a escape.
2a is provided, and the rear end face of the valve case 22 is provided at the end face of the rear head 4 on the cylinder block side.
It opens in 3. At the tip of the valve case 22, through holes 22b are provided at regular intervals along the circumferential direction. The valve case 22 is biased rightward in FIG. 1 by a spring 24 housed in the high pressure chamber 23, and the opening edge of the valve case 22 is in contact with the inner wall of the valve chamber 18. The high pressure chamber 22 and the valve chamber 18 are shut off from each other. The high-pressure chamber 23 communicates with the discharge chamber 10 via the communication passage 25.

The capacity control valve 27 is a bellows 27a.
And a winding spring 27b housed in the bellows 27a.
A fixing plate 27c for fixing one end of the bellows 27a in the communication passage 39, and a valve body 27 provided at the other end of the bellows 27a.
It consists of d and. The inside of the bellows 27a is evacuated, and the valve is closed when the pressure Pw of the crank chamber 6 becomes a predetermined value or less.

A rotor 40 for transmitting the rotation of the shaft 7 to an oscillating plate mounting member 39 is fitted on the outer peripheral surface of the shaft 7 on the front head 5 side.
It is supported by the front head 5 via 1. The lower parts of the mutually facing surfaces of the rotor 40 and the rocking plate mounting member 39 are rotatably connected via a link arm 42. That is, one end of the link arm 42 has the pin 43
Is rotatably connected to the lower side portion of one side surface of the rotor 40, and the other end is rotatably connected to the lower side portion of one side surface of the swing plate mounting member 39 by a pin 44.

A central hole 39a of the swing plate mounting member 39
Is slidably in contact with the outer circumference of a hinge ball 45 which is loosely fitted to the outer circumference of the shaft 7 and axially slidably fitted to the outer circumference of a substantially middle portion of the shaft 7 in the axial direction. On the outer circumference of the shaft 7 between the hinge ball 45 and the rotor 40,
A spring 46 is slidably mounted, and the spring 46 urges the hinge ball 45 toward the cylinder block 2 side (left side in the drawing). A stopper 47 is provided on the shaft 7 on the cylinder block 2 side of the hinge ball 45.
A plurality of disc springs 48 and a coil spring 49 are sequentially interposed on the outer circumference of the shaft 7 between the stopper 47 and the hinge ball 45. The springs 48 and 49 cause the hinge ball 45 to move. It is biased toward the front head 5 side (right side in the figure).

A swing plate 50 is rotatably provided on the swing plate mounting member 39. The tip end 50a of the oscillating plate 50 facing the piston 9 and the piston 9 have a piston rod 5 having balls 51a and 51b at both ends.
1 are rotatably connected to each other. The piston 9 causes the piston rod 5 to move as the swing plate 50 swings.
1, the cylinder 1 reciprocally slides in the cylinder 8 in the axial direction to suck and compress the refrigerant gas.

The oscillating plate 50 is provided with one restrant pin 52 from the vicinity of the center to the outer end thereof.
A slipper 53 is rotatably provided around the outer end of the wristland pin 52. The housing 1
Two guide plates 54 are provided on the inner peripheral surface facing the slipper 53 of the cylinder block 2 from the end surface on the front head 5 side to the inner peripheral surface of the front head 5 and along the axial direction of the drive shaft 7. The restant pin 52 and the slipper 53 are provided so as to move along a groove formed between the two guide plates 54. Therefore, the swing plate 50 is constrained from moving in the circumferential direction of the shaft 7 by the guide plate 54, and swings along the axial direction of the shaft 7 about the hinge ball 45 as a fulcrum.

Next, the operation of the variable displacement type oscillating plate compressor of the embodiment having the above construction will be described.

When the shaft 7 rotates, the shaft 7 rotates together with the rotor 40 and the rocking plate mounting member 39 (the rocking plate 50 rocks with this rotation). Immediately after starting the compressor,
Since the suction pressure Ps is high, the control valve 19 opens,
The refrigerant gas in the crank chamber 6 escapes to the suction chamber 15 through the communication passage 16, but since the opening area of the capacity control valve 27 is larger than the opening area of the control valve, it is introduced from the discharge chamber 10 to the crank chamber 6 through the communication passage 39. The amount of the high-pressure refrigerant gas that is generated is larger than the amount of the refrigerant gas that escapes from the crank chamber 6 to the suction chamber 15, and it takes several seconds (3-5
In the low speed starting region (second), the pressure Pw of the crank chamber 6 does not decrease, but on the contrary, gradually increases (FIG. 2). Therefore,
The oscillating plate 50 maintains a small capacity angle, and small capacity operation is performed. After that, when the rotation of the shaft 7 gradually increases, the throttling function of the orifice 29 greatly affects the rotation of the crank chamber 6
The amount of refrigerant gas escaping from the suction chamber 15 to the discharge chamber 1
The amount of high-pressure refrigerant gas introduced into the crank chamber 6 from 0 increases as a result, the pressure Pw in the crank chamber 6 decreases (FIG. 2), the capacity control valve 27 also closes, and the tilt angle of the oscillating plate 50 increases. , The capacity will gradually increase.

Therefore, even if the compressor is started when the heat load is high, the torque does not suddenly increase, so that the load fluctuation on the engine can be reduced, the idling rotation of the engine can be stabilized, and the engine stall can be stopped. Can be prevented. Further, it is possible to prevent noise and abnormal wear due to impact caused by a rapid increase in torque at startup. Further, since the small capacity operation is forcibly performed for a few seconds (3 to 5 seconds) after the driving, the liquid compression operation can be avoided and the discharge pressure Pd does not become abnormally high.

FIG. 3 is a sectional view showing a capacity control device according to another embodiment. A bellows storage chamber 30 is provided in the cylinder block 2, and a bellows 31 is stored in the bellows storage chamber 30. The bellows 31 has a free end 31a and a capacity control valve 27.
The valve plate 27d is connected with a connecting rod 32, and a passage 33 for introducing the suction pressure Ps into the bellows 31 is provided in the valve plate 3.

According to this embodiment, when the rotation of the shaft 7 increases and the suction pressure Ps gradually decreases, the bellows 31
a contracts, the capacity control valve 27 is pulled in the valve closing direction via the connecting rod 32, the capacity control valve 27 is securely closed, and full stroke operation is started. This low-voltage correction enables more reliable capacity control.

[0024]

As described above, according to the displacement control device for a variable displacement type oscillating plate compressor of the present invention, the control valve is opened immediately after the start of the compressor because the suction pressure is high and the refrigerant gas in the crank chamber is opened. Escapes to the suction chamber 15 through the first communication passage, but since the opening area of the capacity control valve is larger than the opening area of the control valve, the amount of high-pressure refrigerant gas introduced from the discharge chamber to the crank chamber through the second communication passage. Is larger than the amount of refrigerant gas that escapes from the crank chamber to the suction chamber through the first communication passage, and the pressure in the crank chamber does not drop in the low rotation speed range immediately after the start of startup, but rather gradually increases, and The moving plate maintains a small capacity angle, and small capacity operation is performed. Then, when the rotation of the shaft gradually increases, the throttling function of the end of the second communication passage on the discharge chamber side has a large effect, and the amount of refrigerant gas that escapes from the crank chamber to the suction chamber is introduced from the discharge chamber to the crank chamber. The amount of the high-pressure refrigerant gas is increased, and as a result, the pressure in the crank chamber is decreased, the capacity control valve is closed, the tilt angle of the oscillating plate is increased, and the capacity is gradually increased. Therefore, when the heat load is high, the compressor is started and the torque does not suddenly increase.
The fluctuation of the load on the engine can be reduced, the idling rotation of the engine can be stabilized, and the engine stall can be prevented. Further, it is possible to prevent noise and abnormal wear due to impact caused by a rapid increase in torque at startup. Furthermore, since the small capacity operation is forcibly performed immediately after the start of the operation, the liquid compression operation can be avoided and the discharge pressure P
d does not become abnormally high, which contributes to weight reduction and cost reduction of the compressor.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a variable displacement type oscillating plate compressor having a displacement control device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a capacity control device according to another embodiment.

FIG. 3 is a curve diagram showing the relationship between suction pressure Ps, crank chamber pressure Pw, and discharge pressure Pd.

[Explanation of symbols]

 2 Cylinder block 6 Crank chamber 7 Shaft 15 Suction chamber 16 Communication path 19 Control valve 18 Valve chamber 27 Capacity control valve 28 Hole 29 Orifice 39 Communication path 50 Oscillating plate

Claims (1)

[Claims] 1. A first communication path connecting a rotatably supported shaft, a oscillating plate oscillatably mounted on the shaft, a suction chamber and a crank chamber accommodating the oscillating plate. And a valve chamber provided in the middle of the communication passage to close the first communication passage when the suction pressure is equal to or lower than a predetermined value, and open the first communication passage when the suction pressure is equal to or higher than the predetermined value. Is disposed in the valve chamber, and the control valve regulates the pressure in the crank chamber to change the tilt angle of the oscillating plate, and the displacement control device of the oscillating plate compressor of variable displacement type, A second communication passage that connects the chamber and the crank chamber is provided, and a capacity control valve that closes the second communication passage when the pressure in the crank chamber becomes a predetermined value or less is disposed in the middle of the second communication passage. The opening surface of this capacity control valve The capacity control device for a variable displacement type oscillating plate compressor, wherein the product is made larger than the opening area of the control valve and the end of the second communication passage on the discharge chamber side is narrowed.