JPH06221265A - Oscillating swash plate type variable capacity compressor - Google Patents

Abstract

PURPOSE:To improve lubricity of the respective sliding parts in a crank chamber in the zero capacity state where a compressor is operated with inclination of a swash plate at zero. CONSTITUTION:A rotary support 9 is fitted and fixed to a rotary shaft, a swash plate 13 is installed on the rotary support 9 through a hinge mechanism K1 in such a manner as to tilt forward and backward in the reciprocating manner, the swash plate 13 is moved forward and backward by the rotation of the rotary shaft to cause one end piston to reciprocate in a cylinder bore, and coolant gas taken in from an intake chamber is compressed in the cylinder bore to be discharged to a discharge chamber. The compressor is provided a swash plate inclination zero forced changing mechanism K2 for returning the inclination of the swash plate to zero. Further, there is provided a control device 57 for operating the swash plate angle return driving mechanism K2 during a designated time by a timer 59 when a compressor is started to temporarily hold the swash plate 13 from the zero to the tilting state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing 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 this problem, a swing swash plate type compressor having a clutch mechanism has been proposed. As this compressor, there is a compressor disclosed in JP-A-3-37378. 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. In addition, this compressor is provided with a passage opening / closing device at the suction pipe connected to the suction chamber or at the inlet to the suction chamber, and the crank chamber and the suction chamber are constantly communicated with each other by a narrow tube, and the discharge chamber and the crank chamber are connected to each other. It has a pressure control valve that opens when the pressure reaches a set value or less.

When the discharge from the compressor is unnecessary, the passage opening / closing valve is closed, the pressure in the suction chamber drops, the pressure control valve opens, and high-pressure gas flows into the crank chamber. As the pressure in the crank chamber rises, the tilt angle of the swash plate shifts toward the minimum value. Therefore, the stroke of the piston becomes the minimum value, and the required torque becomes an extremely small value. Furthermore, the reciprocating motion of the extremely small piston required to generate the gas flow that flows from the discharge chamber to the crank chamber through the sliding parts and then from the crank chamber to the suction chamber through the outlet hole that is the throttle part compresses the gas. The inside of the machine is lubricated.

[0005]

In the conventional compressor, when the discharge from the compressor is unnecessary, the suction pipe is closed by the opening / closing valve, and the inside of the compressor is lubricated for lubrication of each sliding portion. At this point, a small amount of refrigerant gas is circulated. However, since the refrigerant gas is circulated only inside the compressor, there arises a problem that lubrication is insufficient in each sliding portion in the crank chamber. That is, when the 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, and the swash plate is displaced to the minimum tilt angle. At this time, when the temperature is low such as in winter, a large amount of refrigerant gas is liquefied and accumulated in the crank chamber. Since the compressor is started in the presence of this liquid refrigerant and the liquid refrigerant is difficult to gasify even if the operation is continued at the minimum capacity, the oil adhered to each sliding part due to the circulation of the liquid refrigerant inside the compressor It is washed away, the lubricity deteriorates, and the power loss increases.

Recently, the applicant of the present application has proposed a variable displacement compressor of a type in which the inclination angle of the swash plate is set to zero and the compressor is operated in a zero displacement state in order to further reduce power loss in the clutchless state of the compressor. Also in the case of this compressor, the above-mentioned problem of insufficient lubrication similarly occurs.

An object of the present invention is to solve the problems existing in the above-mentioned prior art and improve the lubricity of each sliding portion inside the compressor in a zero capacity state in which the swash plate is operated at an inclination angle of substantially zero degrees. An object of the present invention is to provide a swingable swash plate type variable displacement compressor that can be used.

[0008]

In order to achieve the above object, the present invention provides a cylinder block in which a plurality of cylinder bores for accommodating a single-headed piston are formed in parallel with each other, and a crank chamber is provided in the housing. Is provided to support the rotary shaft, the rotary support is fixed to the rotary shaft, 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. Rotation of the swash plate to reciprocate the single-headed piston in the cylinder bore so that the refrigerant gas sucked from the suction chamber is compressed in the cylinder bore and discharged to the discharge chamber. By changing the reciprocating stroke of the piston by changing the tilt angle of the swash plate by the pressure difference between the crank chamber pressure acting on the back side of the In the swash plate type variable displacement compressor that is configured to adjust the discharge capacity, the inclination angle of the inclined plate force changing mechanism for changing the inclination angle of the swash plate in the non-operational position,
A swash plate tilt angle returning mechanism for returning the tilt angle of the swash plate from a non-operating position to an operating position, and the swash plate tilt angle returning mechanism for canceling the swash plate tilt angle forced changing mechanism in a non-operating operation state of the compressor. For a predetermined time to temporarily hold the swash plate in the compressed state from the non-operating position. Here, the non-operating position means that the compressor does not substantially discharge,
The swash plate tilt angle at which the function as the compressor is stopped is shown. For example, the swash plate tilt angle can be set to zero degrees.

[0009]

According to the present invention, the swash plate tilt angle returning means is temporarily actuated by the control device when the swash plate is held at the non-operating tilt angle and the compressor is in the zero capacity operation state. Held in a state. Therefore, the compression operation of the compressor is performed, the liquid refrigerant existing in the compressor is discharged from the discharge chamber to the external refrigerant gas discharge pipeline, and the refrigerant gas is sucked into the suction chamber from the external refrigerant gas suction pipeline. The refrigerant gas is compressed in the cylinder bore and then discharged into the discharge chamber. Further, the refrigerant gas containing the lubricating oil is blown 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 disappears. Therefore, even if the swash plate tilt return mechanism is stopped and the swash plate tilt forced change mechanism displaces the swash plate in a non-operational state, and there is no liquid refrigerant inside the compressor even when the compressor shifts to zero capacity operation. The sliding parts in the crank chamber are lubricated with lubricating oil.

[0010]

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, which is a drive source, 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 at one end thereof, and are supported in parallel with each other. Furthermore, both guide pins 15, 1
The other 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 anchors a pair of front and rear shoes 18 and 18 in a state in which the swash plate 13 is inserted into a recess formed at the base end of a plurality of single-headed pistons 17 housed in a cylinder bore 1a. ing. A stopper 19 is attached to the outer circumference of the rotary shaft 4 to prevent the compressor from discharging by restricting the inclination angle of the swash plate 13 to zero, that is, restricting the position of the swash plate support 12. The maximum tilt angle of the swash plate 13 is regulated by the swash plate support 12 coming into contact with the step portion 4a formed on the rotary shaft 4.

A suction hole 2 is provided between the rear end surface of the cylinder block 1 and the front end surface of the rear housing 3.
0a, a valve plate 20 having a discharge hole 20b is interposed. A suction valve plate 21 having a suction valve 21a is joined to the front surface of the valve plate 20, and a discharge valve plate 22 having a discharge valve 22a is joined to the rear surface thereof. A retainer plate 23 having a retainer 23a that regulates the open position of the discharge valve 22a is joined to the rear surface of the discharge valve plate 22.

Next, the swash plate tilt angle returning mechanism K2 for returning the swash plate 13 from the non-operating position to the operating 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 radial bearing 6 and the spool 2
A lip seal 25 is provided between the lip seals 4 and 4. 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 state.

At the center of the rear housing 3, as 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, an electromagnetic direction switching valve 31 is provided in the oil discharge passage 29, and the switching valve 31 is provided with a swash plate inclination angle formed in the cylinder block 1 and the rear housing 3. It is connected to the pressure chamber 26 via a return oil supply passage 32. The direction switching valve 31 is selectively switchable between a first port 31a communicating with the oil passage 30 and a second port 31b communicating with the oil supply passage 32.

The structure of the electromagnetic directional control valve 31 will be described with reference to FIGS. As shown in FIG. 6, first and second valve chambers 34 and 35 are formed in the valve case 33, and a cylindrical first valve body 36 and a spherical second valve chamber 36 are formed therein.
The valve body 37 is accommodated, and the second valve body 37 is always urged by the return spring 38 in the direction to close the swash plate inclination return oil supply passage 32 (second port 31b). An electromagnetic solenoid 39 is attached to the upper portion of the valve case 33,
Inside the coil 40 is a fixed iron core 41 and a movable iron core 42.
Is housed. The movable iron core 42 has the first operating rod 4
The base end portion of 3 is inserted and fixed, and the middle portion thereof is loosely penetrated through an insertion hole formed at the center of the fixed iron core 41 and is fixed through the first valve body 36. Further, the tip of the first actuation rod 43 is in contact with the second valve body 37.

Therefore, in the demagnetized state of the coil 40, the second valve body 37 is held by the return spring 38 at the position for closing the swash plate tilt angle return oil supply passage 32 (second port 31b) as shown in FIG. At the same time, the first valve body 36 is held at a position where the oil discharge passage 29 (first port 31a) is opened. Therefore, the lubricating oil is supplied to the oil passage 30 by the oil discharge passage 29.
And is lubricated for each sliding portion inside the compressor.
On the contrary, in the excited state of the coil 40, the movable iron core 42 is attracted and moved to the fixed iron core 41 against the urging force of the return spring 38 as shown in FIG. The body 36 is switched to the closed position, and the second valve body 37 is switched to the position where the swash plate tilt angle return oil supply passage 32 is opened.
Therefore, the control oil pressure discharged from the oil supply pump 27 is not supplied to the oil passage 30 in the rotary shaft 4 but is supplied from the tilt return oil supply passage 32 into the pressure chamber 26.
4 is pushed forward, the swash plate support 12 is moved in the same direction, and the swash plate 13 is returned to the inclined state from zero degree.

Next, based on FIGS. 2, 6 and 7, the swash plate 1 will be described.
When the compressor 3 is in the tilted state and the compression operation of the compressor is being performed, the swash plate 13 is controlled by the control device 57 of an external control method described in detail later.
Swash plate tilt angle change mechanism K for returning the tilt angle of the
3 will be described.

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. An electromagnetic opening / closing valve 46 is provided in the air supply passage 44. The electromagnetic solenoid of the electromagnetic opening / closing valve 46 is shared with the electromagnetic sonoid 39 of the electromagnetic direction switching valve 31.

As shown in FIG. 6, the solenoid opening / closing valve 46 is
A spherical valve element 4 is provided in a valve chamber 48 formed in the valve case 47.
9 is equipped. The valve body 49 is always biased by a return spring 50 in a direction to close the air supply passage 44. or,
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 tilt angle forced change mechanism K3 of the swash plate 13 is configured.

Therefore, as shown in FIG. 7, 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 a position where the return spring 50 closes the air supply passage 44,
That is, the tilt angle forced change mechanism K3 is held in the inoperative state. Then, as shown in FIG. 8, when the electromagnetic solenoid 39 is demagnetized in a state where the swash plate 13 is tilted and the compressor is being compressed, the return spring 38 on the electromagnetic directional control valve 31 side causes the second The second operating rod 51 is pushed upward through the valve element 37, the first operating rod 43, and the movable iron core 42, and the operating rod 51 moves the valve element 49 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 P acting on the piston 17 is increased.
The differential pressure Δp between c and the suction pressure Ps (hereinafter simply referred to as differential pressure Δp) is increased, and the swash plate 13 is forcibly returned from the inclined state 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 housing 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 sensitive chamber 55 also decreases, and the valve body 53 decreases the opening degree of the extraction passage 45, so the differential pressure Δp increases and the piston 17 increases. Stroke is reduced and the compressor operates at a smaller capacity.

The cylinder block 1 and the valve plate 20 are provided with a bleed passage (not shown) having a fixed throttle that connects the crank chamber 2a and the suction chamber 3a, and is connected to the inner peripheral surface of the cylinder bore 1a during the compression stroke of the piston 17. Refrigerant gas blown by to the crank chamber 2a through the gap on the outer peripheral surface of the piston is returned to the suction chamber 3a.

Next, the control device which is the main part of the present invention will be described. In this embodiment, as shown in FIGS. 1, 2, and 6, when the compressor is stopped, the swash plate inclination angle changing mechanism K is used.
3, the swash plate 13 held at zero degrees is operated by the swash plate tilt angle returning mechanism K2 for a predetermined time when the compressor is started,
Control device 5 for temporarily holding the inclined state and performing the compression operation
Equipped with 7.

As shown in FIG. 6, the electromagnetic solenoid 3
The control device 57 is connected to the coil 40 of 9, and a central processing unit (CPU) 58, a timer 59 capable of setting an energization time to the electromagnetic solenoid 39, an input unit 60, and an instruction unit are connected to the control device 57. 61 is provided.
Further, the control device 57 has various commands and detections such as an engine start switch 62, an air conditioner switch 63, a discharge temperature detector 64, a vehicle interior temperature detector 65, and an intake pressure detector and a discharge pressure detector (not shown). The signal is input. Further, the central processing circuit 58 is provided with a memory 66 so as to store a set time, a set temperature, a set pressure or the like. When the start switch 62 of the engine is turned on, the timer 59 energizes the electromagnetic solenoid 39 for a predetermined time by the timer 59, and the swash plate 13 is temporarily turned from 0 ° to, for example, 10 ° when the compressor is started. Hold and change to the tilt angle.

Next, the operation of the variable capacity compressor configured as described above will be described. When the compressor is stopped, the swash plate 13 is stopped and held at zero degree by the swash plate tilt angle changing mechanism K3 of the swash plate 13, as shown in FIG.
The swash plate tilt angle returning mechanism K2 is stopped. 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,
The support arm 11 of the rotary support 9 is revolved around the rotary shaft 4. Therefore, the hinge mechanism K1 starts the rotation of the swash plate 13 in the state of zero degree.

The ON signal of the start switch 62 of the engine is transmitted to the controller 57 in FIGS.
The predetermined time set by the PU 58 and the timer 59,
For example, the electromagnetic solenoid 39 is excited for 10 minutes. Therefore, in FIG. 6, the first valve body 36 closes the first port 31a and the second valve body 37 opens the second port 31b, so that the supply of the lubricating oil to the oil passage 30 by the oil supply pump 27 is stopped. At the same time, pressure oil is supplied to the pressure chamber 26 from the tilt angle oil supply passage 32. As a result, the spool 24 moves forward and the swash plate 13 is moved from the zero degree position shown by the solid line in FIG. 1 to the tilt position shown by the chain line in FIG. The refrigerant gas sucked therein is compressed and then discharged into the discharge chamber 3b. Further, the second operating rod 51 is moved together with the movable iron core 42 by the excitation of the electromagnetic solenoid 39.
7, the valve body 49 of the electromagnetic on-off valve 46 is moved to a position that closes the air supply passage 44 by the return spring 50, as shown in FIG.
The supply of the refrigerant gas to a is stopped.

The spool 24 is stopped by the stopper 19 by the supply of the control oil pressure to the pressure chamber 26,
After that, the control oil pressure is applied to the spool 2 through an oil passage (not shown) that connects the pressure chamber 26 provided on the rotary shaft 4 and the crank chamber 2a.
It is opened by the movement of 4 and is supplied to the crank chamber 2a.

When the operation of the compressor at the intermediate capacity has elapsed for a predetermined time, the electromagnetic solenoid 39 is demagnetized in FIG. 7 due to the time-up of the timer 59, and as shown in FIG. 6, the first valve body 36 of the electromagnetic directional control valve 31. Opens the discharge passage 29 and closes the second valve body 37 by the return spring 38, so that the supply of pressure oil to the pressure chamber 26 is stopped and the spool 2
4 becomes a free state. Further, since the second operating rod 51 opens the valve body 49 of the electromagnetic opening / closing valve 46 against the biasing force of the return spring 50 and opens the air supply passage 44, the discharge chamber 3b.
Is supplied with high-pressure refrigerant gas from the crank chamber 2a to increase the differential pressure Δp acting on the piston 17 in the swash plate 13,
The swash plate 13 is forcibly returned to the zero degree position, and the compressor is switched to zero capacity operation.

As described above, when the compressor is started, it is temporarily operated at an intermediate capacity (for example, 10%). Therefore, even if the liquid refrigerant exists in the compressor, this liquid refrigerant is discharged from the discharge chamber 3b to the external refrigerant gas discharge pipe line, and the refrigerant gas containing the lubricating oil in the condenser and the evaporator is the suction refrigerant gas. It flows into the suction chamber 3a through the suction pipe line. As a result, the lubricating oil outside the compressor returns to the inside of the compressor together with the refrigerant gas, and after the compressor is switched to the zero capacity operation, the lubricity of each sliding portion in the crank chamber 2a is improved.

By the way, the swash plate 1 by the spool 24
The inclination angle of 3 differs depending on the magnitude of the cooling load in the vehicle compartment.
When the temperature inside the vehicle 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 degree of the bleed passage 45, so that the differential pressure Δp acting on the piston 17 is reduced. Is kept large, and the swash plate 13 is kept at the minimum inclination angle for 10% 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. But,
When the cooling load is large, the switch 63 of the air conditioner is generally turned on, so that the compressor continues the normal compression operation at the same time when the engine is started. That is, the control device 57 continues to energize the electromagnetic solenoid 39 as shown in FIG. 7 by turning on the air conditioner switch 63, and continues to supply the lubricating oil from the oil supply pump 27 to the pressure chamber 26. Then, the spool 24 is held as it is advanced, the swash plate 13 is swung in an inclined state while its inclination angle is changed according to the cooling load, and a compression operation is performed by the reciprocating motion of the piston 17. During this steady operation, the pressure control valve 5
2, the opening degree of the extraction passage 45 is adjusted according to the fluctuation of the suction pressure Ps proportional to the cooling load, the differential pressure Δp acting on the piston 17 is adjusted, and the inclination angle of the swash plate 13 is changed according to the cooling load. The discharge capacity is adjusted.

When the air conditioner switch 63 is kept off under a heavy cooling load, the swash plate 13 has the maximum inclination and the compressor operates only for a predetermined time. Further, the present invention is not limited to the above embodiment, but can be embodied as follows.

(1) In the above-described embodiment, the swash plate 13 is operated in a tilted state from zero degree only for a predetermined time when the compressor is started by the engine, but instead of this, the control device 57 is used.
Thus, after the compressor is started at zero capacity and a predetermined time has elapsed, or every time a predetermined time elapses, the swash plate 13 may be temporarily inclined to perform the compression operation. In this case, it is conceivable that the predetermined time is set, for example, 10 to 30 before the liquid refrigerant existing inside the compressor is heated and lubricity of each sliding portion becomes a problem.

When the compressor is operating at zero capacity, the temperature inside the crank chamber 2a is detected by the detector, and when the detected temperature exceeds the set value, the swash plate 13 is controlled by the controller 57. May be temporarily tilted to operate the compressor at an intermediate capacity.

Further, when the rotation speed of the rotary shaft 4 reaches a predetermined value or at every predetermined rotation speed, the swash plate 13 is temporarily tilted by the control device 57 so that the compressor operates at an intermediate capacity. May be.

Also in each of these different examples, since the lubricating oil is taken into the compressor together with the refrigerant gas from the external refrigerant gas suction pipe, the lubricity of each sliding portion in the crank chamber is improved.

(2) The control device 57 may temporarily perform the intermediate capacity compression operation after the initial startup of the compressor and after a lapse of a predetermined time. (3) The swash plate tilt angle compulsory changing mechanism K3 of the swash plate 13 may be composed of a coil-shaped return spring (not shown) provided between the rotation support 9 and the swash plate support 12.

(4) As the swash plate tilt angle returning mechanism K2 of the swash plate 13, instead of the system of the oil supply pump 27 and the spool 26,
For example, an electromagnetic solenoid (not shown) that pushes the swash plate support 12 may be used.

(5) The CPU 58 and the timer 59 of the control device 57 may be used to change and adjust the time during which the swash plate tilt angle returning mechanism K2 is operated according to the magnitude of the cooling load.

[0043]

As described above in detail, the present invention releases the swash plate tilt angle forced change mechanism and operates the swash plate tilt angle restoring mechanism for a predetermined time to operate the swash plate while the compressor is operating at zero capacity. Since the control device for temporarily holding the inclining state from the non-operating position is provided, it is possible to improve the lubricity of each sliding portion of the crank chamber when the compressor is operated at zero capacity, and It has the effect of increasing durability.

[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 zero displacement 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 cross-sectional view showing an electromagnetic directional control valve, an electromagnetic opening / closing valve, and a pressure control valve.

FIG. 7 is a longitudinal sectional view showing an electromagnetic directional control valve, an electromagnetic opening / closing valve, and a pressure control valve.

FIG. 8 is a vertical cross-sectional view showing the entire swash plate type variable displacement compressor in a large capacity state.

[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 ... Electromagnetic directional control valve, 32 ... Inclination return oil supply passage, 39 ... Electromagnetic solenoid, 44 ... Air supply passage, 46 ... Electromagnetic on-off valve, K1 ... Hinge mechanism, K2 ... Swash plate tilt angle return mechanism, K3 ... Swash plate tilt angle forced change mechanism.

Front page continuation (72) Inventor Tomohiko Yokono 2-chome Toyota Town, Kariya City, Aichi Stock Company Toyota Industries Corp. (72) Inventor Ken Mizuto 2-chome Toyota Town, Kariya City, Aichi Stock Company Inside Toyota Industries Corporation

Claims (1)

[Claims] 1. A cylinder block in which a plurality of cylinder bores for accommodating a single-headed piston are formed in parallel with each other in a housing, a crank chamber is provided in the housing to support a rotary shaft, and the rotary shaft is rotated by the rotary shaft. The support is fixed, and a swash plate is attached to the rotary support via a hinge mechanism so as to be capable of reciprocating forward and backward, and the swash plate is swung back and forth by the rotation of the rotary shaft to move the single-headed head. The piston is reciprocated in the cylinder bore so that the refrigerant gas sucked from the suction chamber is compressed in the cylinder bore and discharged to the discharge chamber. Furthermore, the crank chamber pressure acting on the back side of the piston and the bore acting on the front side Swing swash plate type variable displacement configured to adjust the displacement 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 the compressor, a swash plate angle forced change mechanism for changing the tilt angle of the swash plate to a non-operating position, and a swash plate angle returning mechanism for returning the tilt angle of the swash plate from the non-operating position to the operating position, A control device for releasing the swash plate tilt angle forced changing mechanism in a non-operating state of the compressor, and operating the swash plate tilt angle returning mechanism for a predetermined time to temporarily hold the swash plate in a compressed state from the non-operating position; Swing swash plate type variable displacement compressor with.