JPH06213149A - Clutch-less rocking swash plate variable-capacity compressor - Google Patents

Abstract

PURPOSE:To assure the capacity return by discharging a liquid refrigerant to the outside of a compressor when the compressor is started even if the liquid refrigerant exists in a crank chamber at the stop state of the compressor, and guiding a lubricant required for the capacity return from the clutch-less state into the crank chamber from an external refrigerant circuit. CONSTITUTION:A swash plate 13 is fitted reciprocatively tiltably in the longitudinal direction to a rotation supporter 9 fixed to a rotary shaft 4 via a hinge mechanism K1. An exciting spring 33 returning the swash plate 13 from 0 deg. to the tilt position and a spool 24 are provided on the rotary shaft 4. The center of gravity W of the swash plate 13 itself is displaced below the center axis O of the rotary shaft 4 by the first tilt angle changing means K3 changing the tilt angle of the swash plate 13 to 0 deg., and the swash plate 13 is returned from the tilt position to the 0 deg. position by the centrifugal force when the swash plate 13 is rotated for the transition to the clutch-less state. The swash plate 13 is temporarily held at the tilt position when a compressor is started, and the refrigerant gas containing a lubricant is fed into the compressor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutchless rocking swash plate type variable displacement compressor used in, for example, an air conditioner for automobiles.

[0002]

2. Description of the Related Art Generally, a variable displacement compressor for an automobile has
When the electromagnetic clutch that connects and disconnects the power of the engine is installed, the temperature inside the vehicle compartment is high, and the electromagnetic clutch is activated by turning on a switch of an air conditioner (hereinafter referred to as an air conditioner), the rotational movement of the engine causes the belt transmission mechanism and the electromagnetic transmission. It is transmitted to the compressor via the clutch. For this reason, the compressor is started and stopped with a large capacity each time the air conditioner switch is turned on and off, and its durability is reduced due to frequent repetitions of electromagnetic clutch engagement and disengagement. The machine is large and heavy, and it is difficult to install due to the installation space in the engine room.

In order to solve the above problems, a clutchless rocking swash plate type variable displacement compressor has been proposed. As this compressor, there is a compressor disclosed in JP-A-3-143725. In this compressor, the maximum stroke of the piston is variable by continuously changing the inclination angle of the swash plate by controlling the differential pressure between the crank chamber in which the swash plate is housed and the working chamber in the cylinder bore during the intake stroke. Further, this compressor is provided with a hydraulic actuator that pushes the swash plate from the zero degree position and holds the tilted position greater than zero degree in response to an ON signal of the air conditioner switch.

[0004]

When the conventional compressor is stopped during large-capacity operation, high pressure refrigerant gas is supplied from the discharge chamber into the crank chamber to increase the differential pressure acting on the piston. Displace the plate to the minimum tilt. At this time, a large amount of refrigerant gas is liquefied and accumulated in the crank chamber when the outside temperature is low such as in winter when the compressor is stopped. In the presence of this liquid refrigerant, the lubricating oil having a smaller specific gravity than the liquid refrigerant is stored on the liquid refrigerant, so that the lubricating oil at the bottom of the crank chamber becomes insufficient. Therefore, even if the compressor is started in the zero capacity state and then the hydraulic actuator pumps up the lubricating oil from the bottom of the crank chamber to try to return the swash plate from the zero degree position to the inclined position, the actuator does not function and the capacity is restored. There was a problem that you can not do.

An object of the present invention is to solve the problems existing in the above-mentioned conventional techniques, so that even if the liquid refrigerant is present in the crank chamber when the compressor is stopped, the liquid refrigerant is discharged outside the compressor when the compressor is started. To provide a clutchless rocking swash plate type variable displacement compressor that discharges and introduces the lubricating oil necessary for capacity restoration from the clutchless state from the external refrigerant circuit into the crank chamber to reliably perform capacity restoration. is there.

[0006]

To achieve the above object, the present invention provides a clutchless rocking swash plate type variable displacement compressor which holds a swash plate at an inclined position while the compressor is stopped. Means, first tilt angle changing means for displacing the swash plate held at the tilt position by the swash plate tilt position holding means to zero degrees after a predetermined time has passed, and an external control signal generator. A hydraulic drive means for returning the tilt angle of the swash plate from a zero degree to a tilt position by an ON operation signal, and an OFF operation signal from an external control signal generator for shifting the tilt angle of the swash plate from the tilt position to zero degrees. And a second tilt angle changing means.

[0007]

In the stopped state of the compressor, the swash plate tilt position holding means holds the swash plate at the tilt position. When the compressor is started in this stopped state, the swash plate is inclined, so that the medium capacity operation is performed. Then, the compression operation is performed until the swash plate is displaced to zero degree by the first inclination changing means after a predetermined time has elapsed, and the liquid refrigerant existing in the compressor is discharged from the discharge chamber to the external refrigerant gas discharge pipe line. The refrigerant gas is discharged, and the refrigerant gas is sucked into the suction chamber from the external refrigerant gas suction pipe line. The refrigerant gas is compressed in the cylinder bore and then discharged to the discharge chamber. In addition, the refrigerant gas containing lubricating oil is blow-by from the working chamber in the cylinder bore to the crank chamber through the gap between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder bore, and the liquid refrigerant in the crank chamber is recirculated from the extraction passage to the suction chamber, After being sucked in, it is discharged from the discharge chamber to the external refrigerant gas line. Therefore, the lubricating oil is stored at the bottom of the crank chamber.

When the hydraulic drive means is operated by an ON signal from the external control signal generator while the swash plate is moved to zero and the compressor is operating at zero capacity, the drive means operates the bottom portion of the crank chamber. The lubricating oil stored in the pump is pumped up, and the hydraulic pressure reliably returns the swash plate to the inclined state.

Further, when the second tilt angle changing means is operated by the OFF signal from the external signal generator while the compressor is normally performing the compression operation, the swash plate is returned from the tilted state to the zero degree position. It

When the compressor is stopped during zero capacity operation, the swash plate tilt position holding means returns the swash plate to the tilt position.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 2, a front housing 2 forming a crank chamber 2a is joined and fixed to a front end surface of a cylinder block 1 having a plurality of cylinder bores 1a. At the rear end of the cylinder block 1, a rear housing 3 that defines and forms a suction chamber 3a and a discharge chamber 3b is joined and fixed. A rotary shaft 4 is rotatably supported by the cylinder block 1 and the front housing 2 via radial bearings 5 and 6 so as to be located in the crank chamber 2a. A pulley 7 is fixed to the outer end of the rotary shaft 4, and the rotational movement of the engine is directly transmitted by a belt 8.

A rotary support 9 is fitted and fixed to the rotary shaft 4, and a thrust bearing 10 for supporting a thrust load during a compression operation is interposed between the support 9 and the inner wall of the front housing 2. A support arm 11 having an insertion hole 11a is integrally formed with the rotary support 9. On the other hand, a swash plate support 12 having a spherical surface 12a is supported on the rotary shaft 4 so as to be capable of reciprocating in the front-back direction along the outer peripheral surface of the rotary shaft 4, and the swash plate 13 is mounted on the swash plate support 12. It is supported so as to be tiltable in the front-rear direction along the spherical surface 12a. The support pin 1 is inserted into the insertion hole 11a of the support arm 11.
4 is rotatably supported and penetrates in a direction orthogonal to the rotary shaft 4 as shown in FIG. 3, and a pair of left and right guide pins 15 are provided in guide holes 14a formed in the left and right ends of the support pin 14, respectively. , 16 are slidably guided through and supported in parallel with each other. Furthermore, both guide pins 15, 1
The lower end of 6 is press-fitted and fixed in the mounting holes 13b, 13b of the bearings 13a, 13a integrally formed on the back surface of the swash plate 13. In this embodiment, the support arm 11, the swash plate support 12, the guide pins 15 and 16 and the bearing portions 13a and 13a.
The hinge mechanism K1 that allows the swash plate 13 to reciprocate in the front-rear direction is configured by the above.

As shown in FIG. 2, the swash plate 13 is inserted into a recess formed at the base end of a plurality of single-headed pistons 17 housed in the cylinder bore 1a, and a pair of front and rear shoes 18, 18 are interposed therebetween. Moored. The inclination angle of the swash plate 13 is zero degrees on the outer circumference of the rotary shaft 4, that is, the swash plate support 1
A stopper 19 for restricting the position of 2 to make the stroke of the piston 17 zero is attached. The maximum inclination angle of the swash plate 13 is regulated by the bearing portion 13a coming into contact with the rotary support 9.

A valve plate 20 having a suction hole 20a and a discharge hole 20b is interposed between the rear end surface of the cylinder block 1 and the front end surface of the rear housing 3 as shown in FIG. In addition, a suction valve plate 21 having a suction valve 21a formed on the front surface of the valve plate 20.
However, a discharge valve plate 22 having a discharge valve 22a is joined to the rear surface thereof. The discharge valve 22 is provided on the rear surface of the discharge valve plate 22.
A retainer plate 23 having a retainer 23a that regulates the open position of a is joined.

Next, the hydraulic drive means K2 for returning the swash plate 13 from the tilt angle zero degree position to the tilt position will be described. As shown in FIGS. 1 and 2, a cylindrical spool 24, which is slidably guided by the outer peripheral surface of the rotary shaft 4 and reciprocates in the front-rear direction, is housed in the center hole 1b of the cylinder block 1. The rear side radial bearing 6 and the spool 24
A lip seal 25 is provided between and. The outer peripheral surface of the large-diameter cylindrical portion 24a formed at the tip of the spool 24 is slidably contacted with the inner peripheral surface of the center hole 1b, and the small-diameter cylindrical portion 24 is formed.
A pressure chamber 26 is formed between the outer peripheral surface of b and the central hole 1b. Then, when the control hydraulic pressure is supplied to the pressure chamber 26 in a state where the front end of the large-diameter cylindrical portion 24a of the spool 24 is in contact with the rear end surface of the swash plate support 12, the spool 24
Are guided by the rotating shaft 4 to push the swash plate support 12 forward, and the swash plate 13 is returned from the zero degree to the inclined position.

In the pressure chamber 26, there is a biasing spring 33 as a swash plate tilt position holding means for biasing the spool 24 forward to hold the swash plate 13 in the intermediate capacity position when the compressor is stopped. It is housed. Reference numeral 34 is a C-shaped stop ring engaged with the inner peripheral surface of the center hole 1b, and also regulates the position of the lip seal 25.

Hollow portions 15a and 16a are formed inside the guide pins 15 and 16 except for the lower end portion, and the center of gravity W of the guide pins 15 and 16 and the swash plate 13 is the central axis of the rotary shaft 4. It is located below O, that is, on the opposite side of the support pin 14. Then, when the guide pins 15 and 16 and the swash plate 13 are rotated by the rotation of the rotary shaft 4,
Due to the position of the center of gravity W, both guide pins 15 and 16 and the swash plate 13 are moved by the centrifugal force against the urging force of the urging spring 33 in the direction of retracting the spool 24 together with the rotary support 12. There is. In this embodiment, after the compressor is started by setting the position of the center of gravity W of the swash plate, the swash plate 13 held in the inclined position by the biasing spring 33 is returned to the zero degree position after a lapse of a predetermined time. Change means K
Make up three.

At the center of the rear housing 3 is shown in FIG.
As shown in FIG. 4, a trochoidal type oil supply pump 27 driven by the rotary shaft 4 is housed. This refueling pump 2
7 is an outer tooth body 27a and an inner tooth body 27b as shown in FIG.
Consists of. When the outer tooth body 27a is rotated by the rotating shaft 4, the inner tooth body 27b rotates in the same direction at a slower speed than the outer tooth body 27a. As shown in FIG.
The space V between the teeth 27a and 27b moves in the rotation direction of the teeth 27a and 27b while increasing and decreasing in volume due to the difference in rotation speed of the teeth 27a and 27b. Oil is sucked into the space V from the arc-shaped suction port 28a, and oil sucked into the space V is discharged from the arc-shaped discharge port 29a. As shown in FIG. 2, an oil suction passage 28 communicating with the bottom of the crank chamber 2a is connected to the suction port 28a of the oil supply pump 27. Further, the discharge port 29a of the oil supply pump 27 is connected to the rear side opening of the oil passage 30 formed at the center of the rotary shaft 4 by the oil discharge passage 29. The oil passage 30 is formed with branch oil passages 30a at a plurality of locations, and the bearings 5, 6 and the crank chamber 2 are provided.
The lubricating oil can be supplied to the a, the swash plate support 12, and the like.

Further, as shown in FIGS. 1 and 2, a first electromagnetic opening / closing valve 31 is provided in the oil discharge passage 29, and the oil discharge passage 2 between the opening / closing valve 31 and the oil supply pump 27 is provided.
Reference numeral 9 denotes the pressure chamber 2 via an oil supply passage 32 for returning the tilt angle of the swash plate formed in the cylinder block 1 and the rear housing 3.
Connected to 6. When the oil discharge passage 29 is closed by the first electromagnetic opening / closing valve 31, the oil supply to the oil passage 30 is cut off, and the swash plate tilt angle from the oil supply pump 27 through the oil supply passage 32 to the pressure chamber 26 is increased. The control hydraulic pressure for return is supplied.

Therefore, the structure of the first electromagnetic on-off valve 31 will be described with reference to FIGS. As shown in FIG. 6, a valve chamber 37 is formed in the valve case 36, and a cylindrical valve body 38 is accommodated in the chamber 37. The valve case 3
An electromagnetic solenoid 39 is attached to the upper part of the coil 6, and a fixed iron core 41 and a movable iron core 42 are housed inside the coil 40. The base end portion of the first operating rod 43 is inserted and fixed to the movable iron core 42, and the intermediate portion thereof is loosely penetrated through the insertion hole formed at the center of the fixed iron core 41 and fixedly penetrated through the valve body 38. There is.

Therefore, when the coil 40 is demagnetized, the valve body 38 is held at a position where the oil discharge passage 29 is opened, as shown in FIG. Therefore, the lubricating oil is supplied to the oil passage 30 through the oil discharge passage 29, and the sliding portions inside the crank chamber 2a are lubricated. On the contrary, when the coil 40 is in the excited state, the movable iron core 42 is moved to the fixed iron core 41 as shown in FIG.
And the valve element 38 is moved to the closed position by the first operating rod 43. Therefore, the control oil pressure discharged from the oil supply pump 27 is not supplied to the oil passage 30 in the rotating shaft 4 but is supplied from the tilt return oil supply passage 32 into the pressure chamber 26, so that the spool 24 is pushed forward. Then, the swash plate support 12 is moved in the same direction, and the swash plate 13 is returned to the inclined position from zero degree.

An oil discharge passage 30b which connects the pressure chamber 26 and the oil passage 30 is formed in the rotary shaft 4, and the spool 2
When 4 is moved to the most forward position where it abuts on the stopper 19, the oil discharge passage 30b is opened and the control hydraulic pressure supplied from the oil supply pump 27 to the pressure chamber 26 through the oil supply passage 32 is transferred to the oil discharge passage 30b. To the oil passage 30 to prevent abnormal pressure rise in the pressure chamber 26.

Next, referring to FIGS. 2, 7 and 8, the swash plate 1 will be described.
The second tilt angle changing means K4 for shifting the tilt angle of the swash plate 13 to zero degrees by the control device 57 of an external control method described later while the compressor 3 is in the tilt position and the compression operation of the compressor is being performed. To do.

As shown in FIG. 2, the rear housing 3 and the cylinder block 1 are provided with an air supply passage 44 which communicates the discharge chamber 3b with the crank chamber 2a, and an extraction passage 45 which communicates the crank chamber 2a with the suction chamber 3a. Has been formed. A second electromagnetic on-off valve 46 is provided in the air supply passage 44. The electromagnetic solenoid of the second electromagnetic opening / closing valve 46 shares the electromagnetic sonoid 39 of the first electromagnetic opening / closing valve 31.

As shown in FIG. 6, the second electromagnetic opening / closing valve 46 has a spherical valve body 49 inside a valve chamber 48 formed in a valve case 47. The valve body 49 is always biased by a return spring 50 in a direction to close the air supply passage 44.
A second operating rod 51 is coaxially connected to the upper end of the movable iron core 42 of the electromagnetic solenoid 39, and the upper end of the operating rod 51 is in contact with the lower surface of the valve body 49. In this way, the second inclination changing means K4 of the swash plate 13 is configured.

Therefore, as shown in FIG. 8, when the electromagnetic solenoid 39 is in the excited state, the movable iron core 42 moves the second operating rod 51 away from the valve body 49, and the valve body 4 is moved.
9 is held by the return spring 50 in a position to close the air supply passage 44. Then, as shown in FIG. 9, when the electromagnetic solenoid 39 is demagnetized in a state where the swash plate 13 is in the inclined position and the compressor is being compressed, the spring 56a in FIG.
The valve body 38, the first actuating rod 43, the movable iron core 42, and the second actuating rod 51 are moved upward against the biasing force of the return spring 50 by the bellows 56 having the valve element 49. Is moved to a position where the air supply passage 44 is opened. Therefore, high-pressure refrigerant gas is supplied from the discharge chamber 3b to the crank chamber 2a through the air supply passage 44, and the crank chamber pressure Pc and suction pressure Ps acting on the piston 17 are supplied.
The differential pressure Δp (hereinafter, simply referred to as the differential pressure Δp) between and is increased, and the swash plate 13 is forcibly returned from the inclined position to the zero degree position.

By the way, during the compression operation of the compressor, the capacity variable control is automatically performed according to the cooling load. That is,
The differential pressure Δp acting on the piston 17 is adjusted by adjusting the opening degree of the bleed passage 45 that connects the crank chamber 2a and the suction chamber 3a according to the suction pressure Ps that is proportional to the cooling load. ing. The pressure control valve 52 for controlling this discharge capacity will be described below.

As shown in FIG. 6, in the valve case 47, a storage chamber 47a is located below the valve chamber 48.
A valve body 53 having a cylindrical shape with a lid for opening and closing the extraction passage 45 is accommodated in the accommodation chamber 47a. The valve body 53 is always urged in the valve closing direction by the return spring 54. A pressure sensitive chamber 55 is formed on the upper side of the head of the valve body 53, and the chamber 55 senses the suction pressure Ps in the suction chamber 3a through the bleed passage 45 on the downstream side of the valve body 53. And
The opening degree of the extraction passage 45 by the valve body 53 is adjusted by the fluctuation of the suction pressure Ps detected by the pressure sensing chamber 55 and the biasing force of the return spring 54. Further, the pressure-sensitive chamber 55 is connected to a chamber 47b formed between the inner peripheral surface of the valve body 53 and the bellows 56 by a communication passage 53a formed in the head of the valve body 53. An insertion hole 53b is formed in the valve body 53 so as to slidably pass through the second operating rod 51.

Therefore, the cooling load is large and the suction pressure Ps
Is large, the pressure in the pressure-sensitive chamber 55 is large and the valve body 53 is opened, so that the extraction passage 4 from the crank chamber 2a is opened.
A large amount of gas flows into the suction chamber 3a through 5, so that the differential pressure Δp acting on the piston 17 decreases, the stroke of the piston 17 increases, and the compressor operates with a large capacity. On the contrary, when the cooling load decreases and the suction pressure Ps decreases, the pressure in the pressure sensing chamber 55 also decreases, and the valve body 53 decreases the opening degree of the extraction passage 45. Therefore, the differential pressure Δp increases and the piston 17 decreases. Stroke is reduced and the compressor operates at a smaller capacity.

As shown in FIG. 2, the cylinder block 1 and the valve plate 20 are provided with a bleed passage 45A having a fixed throttle for communicating the crank chamber 2a with the suction chamber 3a, and the inner peripheral surface of the cylinder bore 1a during the compression stroke of the piston 17. The refrigerant gas blow-by to the crank chamber 2a is circulated to the suction chamber 3a through the clearance between the outer peripheral surface of the piston and the crank chamber 2a.

As shown in FIG. 6, the electromagnetic solenoid 3
A control device 57 including a microcomputer is connected to the coil 40 of No. 9. Further, an engine start switch 58 and an air conditioner switch 59 as an external signal generator are connected to the control device 57. Further, although not shown, various commands and detection signals for the discharge temperature detector, the vehicle interior temperature detector, the suction pressure detector, the discharge pressure detector, etc. are input to the control device 57.

Next, the operation of the variable displacement compressor configured as described above will be described. When the compressor is stopped, the pressure Pc in the crank chamber, the pressure Ps in the suction chamber 3a and the pressure Pd in the discharge chamber 3b are the same as shown in FIG. Then, the rotary support 12 is moved forward, and the swash plate 13 is stopped and held in the inclined position. Further, the hydraulic drive means K2 is stopped, and the valve body 49 of the second electromagnetic opening / closing valve 46 is moved to the air supply passage 44.
Is held in the open position.

When the engine (not shown) is started in this state, the rotation of the engine is directly transmitted to the rotary shaft 4 via the belt 8 and the pulley 7, and the support arm 1 of the rotary support 9 is supported.
1 revolves around the axis of rotation 4. Therefore, the hinge mechanism K1 rotates the swash plate 13 at the inclined position to start the compression operation of the intermediate capacity. Then, the piston 17 is reciprocated in the cylinder bore 1a, and the refrigerant gas sucked into the cylinder bore 1a from the suction chamber 3a is compressed and then discharged into the discharge chamber 3b.
Is discharged to.

Since the center of gravity W of the swash plate 13 is located below the central axis O of the rotary shaft 4 in FIG. 1 due to the rotational movement of the guide pins 15 and 16 and the swash plate 13, centrifugal force causes the swash plate 13 to rotate. The spool 24 together with the support body 12 is moved and returned to the zero degree position as shown in FIG. 7 against the biasing force of the biasing spring 33. This return time is the thrust force F1 in the thrust direction due to the centrifugal force acting on the swash plate 13, and the urging spring 3
3 and the friction coefficient of each sliding portion. As an example, the zero degree position return time of the swash plate 13 is set to 2 to 5
It can be considered as minutes.

After the swash plate 13 is returned to the zero degree position, the zero capacity operation of the swash plate 13 in the zero degree position, that is, the clutchless state is continued until the air conditioner switch 59 is turned on. In this way, the compressor is compressed at an intermediate capacity (for example, 10%) only for a predetermined time after starting, so that the refrigerant gas is sucked into the compressor from the external refrigerant gas suction pipe line.
Further, even if the liquid refrigerant exists in the crank chamber, the liquid refrigerant is partially gasified and flows into the suction chamber 3a from the extraction passage 45A, is sucked into the cylinder bore 1a, and then is discharged from the discharge chamber 3b into the refrigerant gas discharge pipe line. Is discharged to the outside through. And
The refrigerant gas containing the lubricating oil in the condenser and the evaporator flows into the suction chamber 3a through the suction refrigerant gas suction pipe line. As a result, lubricating oil is stored at the bottom of the crank chamber 2a, and oil for the oil supply pump 27 is secured. Also, the lubricity of each sliding portion in the crank chamber 2a after the compressor is switched to the zero capacity operation is improved.

Next, when the temperature inside the passenger compartment rises and the cooling load increases, and the air conditioner switch 59 is turned on, the electromagnetic solenoid 3 is activated by the operation signal output from the controller 57.
9 is excited. Therefore, as shown in FIG. 8, the valve body 38 closes the oil discharge passage 29, so that the supply of the lubricating oil to the oil passage 30 by the oil supply pump 27 is stopped, and at the same time, from the inclination return oil supply passage 32 to the pressure chamber 26. Is supplied with pressure oil. Therefore, as shown in FIG. 9, the spool 24 moves forward, the swash plate 13 is displaced from the zero degree position to the inclined position, and the compression operation is started.

Further, the second operating rod 51 together with the movable iron core 42 is moved downward against the biasing force of the spring 5a of the bellows 56 by the excitation of the electromagnetic solenoid 39, as shown in FIG. The valve body 4 of the second solenoid on-off valve 46
9 is moved to a position where the air supply passage 44 is closed by the return spring 50, and the supply of the refrigerant gas from the discharge chamber 3b to the crank chamber 2a is stopped.

The supply of the control oil pressure to the pressure chamber 26 stops the spool 24 by the stopper 19.
After that, the control oil pressure is supplied to the crank chamber 2a because the oil discharge passage 30b provided on the rotary shaft 4 is opened by the movement of the spool 24.

When the temperature in the passenger compartment is low and the cooling load is small, the suction pressure Ps is low, so the valve body 53 of the pressure control valve 52 reduces the opening of the extraction passage 45.
Therefore, the differential pressure Δp acting on the piston 17 is kept large, and the swash plate 13 is kept at the minimum inclination angle for the small capacity operation. On the contrary, when the cooling load is large, the suction pressure Ps is large, so the valve body 53 of the pressure control valve 52 increases the opening degree of the bleed passage 45, so that the differential pressure Δp becomes small and the swash plate 13 becomes It moves away from the spool 24 and shifts to the maximum tilt angle. As described above, during the steady operation, the suction pressure P by which the opening degree of the extraction passage 45 is proportional to the cooling load by the pressure control valve 52.
It is adjusted according to the fluctuation of s, the differential pressure Δp acting on the piston 17 is adjusted, the inclination angle of the swash plate 13 is changed according to the cooling load, and the discharge capacity is adjusted.

Air conditioner switch 5 by reducing the cooling load
When 9 is turned off, the electromagnetic solenoid 39 is demagnetized in FIG. 8, and the valve body 38 of the first electromagnetic on-off valve 31 opens the discharge passage 29 as shown in FIG. The supply is stopped and the spool 24 becomes free. The second actuating rod 51 opens the valve element 49 of the second electromagnetic on-off valve 46 against the urging force of the return spring 50 by the urging force of the spring 5a of the bellows 56, and opens the air supply passage 44. Therefore, high-pressure refrigerant gas is supplied from the discharge chamber 3b into the crank chamber 2a, the swash plate 13 is forcibly returned to the zero degree position due to the increase in the differential pressure Δp acting on the piston 17, and the compressor is switched to the zero capacity operation. . At this time, the swash plate 13
In addition to the above-mentioned differential pressure Δp, there is F for pressing the swash plate to the zero degree position
Since 1 acts, the compressor is quickly returned to the zero degree position, and the compressor is operated in the zero capacity state.

In the process of reducing the capacity of the compressor to zero, a large amount of refrigerant gas is supplied into the crank chamber 2a. However, as long as the compressor continues to operate, the rotary support in the crank chamber 2a. Since 9, the guide pins 15 and 16 and the swash plate 13 are rotating, they are not stored as liquid refrigerant at the bottom of the crank chamber 2a. Therefore, lubricating oil is secured at the bottom of the crank chamber 2a, and the next air conditioner switch 59
When the switch is turned on, oil can be pumped up from the crank chamber 2a by the oil supply pump 27, and the tilt angle of the swash plate 13 can be reliably returned from zero degree to the tilt position.

Further, when the engine is stopped, the compressor is also stopped. In this stopped state, the pressure in each chamber in the compressor is the same, so that the swash plate 13 acts on the urging spring 3 as shown in FIG.
By 3 the intermediate tilt angle is restored. Also, when the temperature inside the compressor decreases, the refrigerant gas liquefies in the crank chamber 2a,
This liquid refrigerant causes the lubricating oil that should be stored at the bottom of the crank chamber 2a to float on the upper surface of the liquid refrigerant. Therefore, in the conventional example, even if the swash plate is driven at zero degrees, the oil supply pump is driven by the rotary shaft. I can't pump up oil. However, in the embodiment of the present invention, the compressor can be temporarily operated in the intermediate capacity state at startup, the liquid refrigerant in the crank chamber 2a is discharged to the outside, and the refrigerant gas containing the lubricating oil is compressed from the outside. Since the oil is sucked into the machine, the lubricating oil for capacity restoration is stored in the crank chamber 2a.

In this embodiment, the swash plate 13 is regulated to zero degree in order to bring the compressor into the zero capacity state, but the swash plate 13 is regulated to a slightly inclined position within a range where compression work is not performed. However, in the claims, the zero degree of the swash plate includes this point.

The present invention is not limited to the above embodiment, but can be embodied as follows. (1) In the above embodiment, the biasing spring 33 is housed in the pressure chamber 26, but instead of this, the biasing spring 33 is interposed between the rotary support 9 and the swash plate 13 as shown in FIG. To do. In this case, since the spool 24 is not pressed against the rotary support 12, there is an advantage that no wear occurs.

(2) FIG. 11 shows another example of the first tilt angle changing means K3. In this other example, when the compressor is started, the electromagnetic solenoid 65 is excited and the operating rod 66 thereof is separated from the swash plate 13. Further, the swash plate 13 is displaced from the zero degree position to the inclined position by the biasing spring 33, and the compressor is operated at the intermediate capacity for a predetermined time. Then, after the lubricating oil is collected in the crank chamber 2a, the second electromagnetic on-off valve 46 provided independently of the first electromagnetic on-off valve 31 is excited by the operation signal from the control device 57 to crank the discharge chamber 3b from the crank. The air supply passage 44 of the chamber 2a is opened, the differential pressure Δp acting on the piston 17 is increased, and the swash plate 13 is returned to the zero degree position. Further, the electromagnetic solenoid 65 is demagnetized, the operating rod 66 is moved forward, and the swash plate 13 is held at the zero degree position,
Operate with the compressor clutchless.

(3) The first tilt angle changing means K3 is composed of an electromagnetic solenoid.

[0047]

As described above in detail, according to the present invention, the swash plate tilt position holding means for holding the swash plate in the tilt position when the compressor is stopped, and the swash plate tilt position after the compressor is activated. Since the swash plate held at the inclined position by the holding means is provided with the first inclination changing means for displacing the swash plate to the zero degree position after a predetermined time elapses, compression is performed even if liquid refrigerant exists in the crank chamber when the compressor is stopped. When the machine is started, the liquid refrigerant is discharged to the outside of the compressor, and the lubricating oil necessary for capacity recovery from the clutchless state is introduced into the crank chamber from the external refrigerant circuit.
There is an effect that the capacity can be surely restored.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment in which the present invention is embodied in a swash plate type variable displacement compressor.

FIG. 2 is a vertical cross-sectional view showing the entire swash plate type variable displacement compressor in a small capacity state.

FIG. 3 is a cross-sectional view of the vicinity of a hinge mechanism.

4 is a cross-sectional view taken along the line AA of FIG.

FIG. 5 is a sectional view of an oil supply pump.

FIG. 6 is a vertical sectional view showing an electromagnetic opening / closing valve, an electromagnetic opening / closing valve, and a pressure control valve.

FIG. 7 is a cross-sectional view near a swash plate at a zero degree position.

FIG. 8 is a vertical sectional view showing an electromagnetic opening / closing valve, an electromagnetic opening / closing valve, and a pressure control valve.

FIG. 9 is a cross-sectional view near a swash plate in an inclined position.

FIG. 10 is a sectional view near a swash plate showing another example of the present invention.

FIG. 11 is a sectional view near a swash plate showing another example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cylinder block, 1a ... Cylinder bore, 2 ... Front housing, 2a ... Crank chamber, 3 ... Rear housing, 3a ... Suction chamber, 3b ... Discharge chamber, 4 ... Rotation shaft, 9 ... Rotation support body, 11 ... Support arm, 13 ... Swash plate, 13a ... Bearing part, 14 ... Support pin, 17 ... Piston, 24 ... Spool, 26 ... Pressure chamber, 27 ... Oil supply pump, 31 ... First electromagnetic on-off valve, 32 ... Inclination return oil supply passage, 33 ... biasing spring as swash plate tilt position holding means, 39 ... electromagnetic solenoid,
44 ... Air supply passage, 46 ... Second electromagnetic on-off valve, 59 ... Air conditioner switch as external signal generator, K1 ... Hinge mechanism, K2 ... Hydraulic drive means, K3 ... First tilt angle changing means, K
4 ... Second tilt angle changing means.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Mizuto 2-1-1 Toyota-cho, Kariya city, Aichi stock company Toyota Industries Corp.

Claims (1)

[Claims] 1. A cylinder block in which a plurality of cylinder bores for accommodating a single-headed piston are formed parallel to each other is provided in a housing, and a crank chamber is provided in one of the housings to support a rotary shaft, and the rotary shaft is provided in the rotary shaft. A rotary support is fixed, and a swash plate is attached to the rotary support via a hinge mechanism so as to be capable of reciprocating tilting in the front-rear direction. The single-headed piston is reciprocated in the cylinder bore to compress the refrigerant gas sucked from the suction chamber in the cylinder bore and discharge it to the discharge chamber. Further, the crank chamber pressure acting on the back surface of the piston and the suction acting on the front surface Clutchless rocking configured to adjust the discharge capacity by changing the reciprocating stroke of the piston by changing the tilt angle of the swash plate by the pressure difference with the pressure In a swash plate type variable displacement compressor, a swash plate tilt position holding means for holding the swash plate in a tilt position when the compressor is stopped, and a tilt position by the swash plate tilt position holding means after the compressor is started. First tilt angle changing means for displacing the swash plate to zero degree after a lapse of a predetermined time, and hydraulic drive means for returning the tilt angle of the swash plate from zero degree to a tilt position by an ON operation signal from an external control signal generator. A clutchless rocking swash plate type variable displacement compressor, comprising: a second tilt angle changing means for shifting the tilt angle of the swash plate from the tilt position to zero degrees in response to an OFF operation signal from an external control signal generator.