JPH06200873A - Clutchless structure for single sided piston type variable displacement compressor - Google Patents

Abstract

PURPOSE:To provide a clutchless compressor which surely keeps a condition of a zero capacity by allowing a single drive means to carry out a transfer to a zero capacity and capacity restoration. CONSTITUTION:The tilt angle of a swash plate 14 which is supported over a rotating shaft 7 via a swash plate support body 14 in such a way that the plate can be freely rocked, is controlled by adjusting pressure within a crank room 2a. Pressure within the crank room 2a is controlled by a control valve 25. Switch-over bodies 34A and 34B within a cylindrical body 12 rotating together with the rotating shaft 7 are interlocked with a ball valve 43, and the ball valve 43 is driven so as to be opened/ closed by magnetizing/demagnetizing an electromagnetic solenoid valve 47. When the ball valve 43 is separated from a valve port 41a, high pressure refrigerant gas in a discharge pressure zone 3b1 is supplied to the crank room 2a, so that a swash plate angle becomes zero. And when the swash plate angle becomes zero, a hold ball 37 is pushed by the switch-over body 34A so as to be projected out of the outer circumferential surface of the cylindrical body 12, so that the swash plate support body 14 is thereby held at a position where the swash plate angle becomes zero.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts the rotary motion of a swash plate tiltably supported by a rotary shaft into a reciprocating linear motion of a single-headed piston, and at the same time, through a single-headed piston of a pressure in a crank chamber and a suction pressure. The present invention relates to a clutchless structure in a one-sided piston type variable displacement compressor that controls the tilt angle of a swash plate by the difference.

[0002]

2. Description of the Related Art In a variable displacement type swash plate compressor disclosed in Japanese Patent Laid-Open No. 3-143725, an electromagnetic clutch for connecting and disconnecting power transmission between an external drive source and a rotary shaft of the compressor. Not using. If the electromagnetic clutch is eliminated, it is possible to eliminate the drawback of poor feeling in feeling due to the ON / OFF shock, especially in the vehicle-mounted form, and to reduce the weight and cost of the entire compressor.

In the variable displacement type swash plate compressor disclosed in the above-mentioned prior publication, the pressure in the crank chamber accommodating the swash plate is rapidly increased to bring the swash plate inclination angle to 0 °, and the discharge capacity is made zero. It is designed to be dropped. The load on the compressor sharply decreases due to the sharp decrease in the discharge capacity. When a compressor is installed in a vehicle, it is desirable to direct all of the vehicle engine output to drive the vehicle when accelerating or climbing a vehicle. In such a case, the load on the compressor can be drastically reduced. Be seen.

When the tilt angle of the swash plate is increased from zero and the capacity is restored, the swash plate is pushed in the direction of increasing the tilt angle by the hydraulic actuator. In the conventional device, the discharge chamber and the crank chamber are connected by a gas passage in order to rapidly increase the pressure in the crank chamber, and the first electromagnetic opening / closing valve is provided on this passage. Further, the oil storage portion at the bottom of the crank chamber and the hydraulic actuator are connected by an oil passage, and the second electromagnetic opening / closing valve is interposed on this passage. Therefore, when the discharge capacity is set to zero, the first electromagnetic on-off valve is opened, and when the discharge capacity is restored, the second electromagnetic on-off valve is opened.

[0005]

However, the construction in which two electromagnetic on-off valves are incorporated in the compressor is disadvantageous in that the compressor is upsized and the weight is increased. Further, if the state where the discharge capacity is zero continues, the pressure in the crank chamber escapes to the suction pressure region, and the refrigerant gas pressure in the compressor becomes uniform. Then,
There is a risk that the swash plate will start to tilt arbitrarily and the capacity will be restored arbitrarily.

[0006] It is an object of the present invention to provide a clutchless structure which suppresses an increase in size and weight of a compressor and does not bring about an arbitrary capacity return.

[0007]

Therefore, according to the present invention,
A crank chamber, a suction chamber, a discharge chamber, and a cylinder bore that connects these chambers are defined and formed, and a swash plate support is slidably supported on a rotary shaft inside a housing that accommodates a single-headed piston in a linearly reciprocating linear motion. Then, the swash plate is tiltably supported on the swash plate support, and the swash plate is tiltably linked to the rotary support on the rotary shaft, and the one-head piston for the pressure in the crank chamber and the suction pressure is used. The present invention is directed to a one-sided piston type variable displacement compressor that controls the inclination angle of the swash plate by the difference. In the first aspect, the crank chamber and the discharge pressure region are connected to each other, and the position where the inclination angle of the swash plate is zero on the rotary shaft is obtained. A pressure passage for forcibly changing the tilt angle for supplying pressure for moving the swash plate support from the discharge pressure region to the crank chamber, and an on-off valve for forcibly changing the tilt angle interposed on the pressure path for forcibly changing the tilt angle, Oblique on the rotation axis A zero tilt holding body is provided which is switched between a zero tilt holding position for holding the swash plate support at a position where the tilt angle is zero and a slide allowing position for allowing the swash plate support to slide on the rotation axis. Based on the zero tilt angle holding means and the tilt angle zero command signal output from the external control signal generator, the tilt angle forced change opening / closing valve is opened, and the zero tilt angle holding body is moved from the slide allowable position to the zero tilt angle holding position. A drive means for forcibly changing the tilt angle for switching and a biasing means for restoring the tilt angle of the swash plate for biasing the swash plate support at a position where the tilt angle of the swash plate is zero on the rotating shaft. And a clutchless structure including means.

According to the second aspect of the invention, the zero tilt angle is switched between the slide permitting position which is recessed in the outer peripheral surface of the cylindrical body which is a part of the rotary shaft and the zero tilt angle holding position which projects from the outer peripheral surface of the cylindrical body. The holding member and the switching member housed in the tubular body so as to interlock with the opening / closing operation of the opening / closing valve constitute a zero tilt angle holding means. Then, the switching body is switched between a normal position in which the zero tilt holding body can be retracted in the outer peripheral surface of the cylindrical body, and a restricting position in which the zero tilt holding body is restricted to a zero tilt holding position protruding from the outer peripheral surface of the cylindrical body. It was arranged to switch.

In the third invention, the biasing means for returning the tilt angle of the swash plate is a spring member.

[0010]

The external control signal generator includes the air conditioner switch, the outlet temperature sensor of the evaporator on the external refrigerant circuit, the outside air temperature sensor, the accelerator switch, the lock sensor of the compressor, and the like. When a tilt angle zero command signal is output from such an external control signal generator, the tilt angle forced change drive means opens the tilt angle forced change on-off valve. When the on-off valve for forced tilt change opens, the refrigerant gas in the discharge pressure region flows into the crank chamber through the passage for forced tilt change, and the pressure in the crank chamber rises sharply. Due to this sudden pressure increase, the swash plate tilt angle shifts to zero, and the compressor becomes unloaded. When the on-off valve for forcibly changing the tilt angle is opened, the zero tilt holding body of the zero tilt holding means is arranged to be switched to the zero tilt holding position.
When the compressor is not loaded, the swash plate support is held at a position where the swash plate tilt angle is zero. When the tilt angle return command signal is output from the external control signal generator, the tilt angle forced change drive means closes the tilt angle forced change opening / closing valve, and the zero tilt angle holder can be switched to the slide allowable position. The swash plate support is released from the locking action of the zero tilt holding body, and is slid in the tilt increasing direction by the swash plate tilt return biasing means.

The switching body according to the second aspect of the invention is arranged to be switched between the normal position and the regulation position in conjunction with the tilt angle forced change opening / closing valve. When the switching body is switched to the regulation position, the zero tilt holding body projects from the outer peripheral surface of the cylindrical body which is a part of the rotation shaft, and holds the swash plate support body at a position where the swash plate tilt angle is zero.

The spring member of the third invention biases the swash plate support in the direction of increasing the tilt angle, and when the swash plate support is released from the locking action of the zero tilt holding member, the spring action of the spring member causes the swash plate support to release. It is moved and arranged in the direction of increasing the tilt angle.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. As shown in FIG. 1, a front housing 2 is joined to the front end of a cylinder block 1 which is a part of the housing of the entire compressor. A rear housing 3 is joined and fixed to the rear end of the cylinder block 1 via a valve plate 4, valve forming plates 5A and 5B, and a retainer forming plate 6.

A rotary shaft 7 is rotatably supported on the front housing 2 via a radial bearing 8.
The front end of the rotary shaft 7 projects outward from the crank chamber 2a in the front housing 2, and a pulley 9 is screwed to the projecting end. The pulley 9 is operatively connected to the vehicle engine via a belt 10. A lip seal 11 is interposed between the front end of the rotary shaft 7 and the front housing 2. The lip seal 11 prevents pressure leakage in the crank chamber 2a.

A rotary support 18 is fixed to the rotary shaft 7, and a cylindrical body 12 is press-fitted and connected to the inner end of the rotary shaft 7. The cylindrical body 12 is a radial bearing 13.
It is rotatably supported by the cylinder block 1 via and rotates integrally with the rotary shaft 7.

A spherical swash plate support 14 is slidably supported on a cylindrical body 12 which rotates integrally with the rotary shaft 7, and a swash plate 15 is attached to the swash plate support 14 such that the axis of the cylindrical body 12 is axial. It is supported so that it can tilt in any direction. Radial bearing 13
The seal ring 38 is interposed between the peripheral wall and the cylindrical body 12 of the receiving hole 1a ₁ in the cylinder block 1 containing. The seal ring 38 isolates the radial bearing 13 from the crank chamber 2a. The seal ring 38 is prevented from protruding to the crank chamber 2a by a circlip 39.

A capacity return spring 40 is interposed between the circlip 39 and the swash plate support 14. The capacity return spring 40 serves as a biasing means for restoring the tilt angle of the swash plate that biases the swash plate support 14 toward the rotation support 18.

The maximum inclination angle of the swash plate 15 is regulated by the contact between the inclination regulating projection 18b of the rotary support 18 and the swash plate 15. Further, the minimum tilt angle of the swash plate 15 is restricted by the most contracted state of the capacity return spring 40. The minimum tilt angle of the swash plate 15 when the capacity return spring 40 is in the most contracted state is 0 °.

Connecting pieces 16A and 16B are fixed to the swash plate 15. As shown in FIG. 3, a pair of guide pins 17A and 17B are fixedly attached to the connecting pieces 16A and 16B.
A support arm 18a is provided so as to project from the rotary support 18. As shown in FIG. 3, the support pin 18 is attached to the support arm 18a.
9 is rotatable and is pierced and supported in a direction perpendicular to the rotary shaft 7. The pair of guide pins 17A and 17B are slidably fitted into both ends of the support pin 19. The support pin 19 on the support arm 18a and the pair of guide pins 17A and 17B cooperate with each other so that the swash plate 15 can be tilted in the axial direction of the rotary shaft 7 and the cylindrical body 12 about the swash plate support 14 and the rotary shaft 7 and It can rotate integrally with the cylindrical body 12. The tilting of the swash plate 15 is performed by the support pin 19 and the guide pin 17
It is guided by the slide guide relationship with A and 17B, the sliding action of the swash plate support 14 and the supporting action of the swash plate support 14.

A single-head piston 20 is housed in a cylinder bore 1b penetrating the cylinder block 1 so as to be connected to the crank chamber 2a. A pair of shoes 21 is fitted in the neck portion 20 a of the one-headed piston 20. Swash plate 1
The peripheral portion of 5 enters between both shoes 21, and the end faces of both shoes 21 are in contact with both surfaces of the swash plate 15. Therefore, the swash plate 15
Is converted into forward and backward reciprocating swing of the single-headed piston 20 via the shoe 21, and the single-headed piston 20 moves back and forth in the cylinder bore 1b.

As shown in FIGS. 1 and 5, the rear housing 3 has a suction chamber 3a and a discharge chamber 3b defined therein. An intake port 4a and a discharge port 4b are formed on the valve plate 4. A suction valve 5a is formed on the valve forming plate 5A, and a discharge valve 5b is formed on the valve forming plate 5B. The refrigerant gas in the suction chamber 3a is sucked into the suction port 4a by the returning movement of the single-headed piston 20.
The intake valve 5a is pushed away from the inside to flow into the cylinder bore 1b. The refrigerant gas flowing into the cylinder bore 1b is discharged to the discharge chamber 3b by pushing the discharge valve 5b away from the discharge port 4b by the forward movement of the single-headed piston 20. Discharge valve 5b
Is brought into contact with the retainer 6a on the retainer forming plate 6 to regulate the opening.

As shown in FIGS. 1 and 6, a discharge flange 22 is formed on the upper surface of the cylinder block 1, and a discharge port 1c is provided in the discharge flange 22. An oil separation hole 22a having a circular cross section is recessed in the discharge port 1c. The oil separation hole 22a is connected to the discharge chamber 3 through the discharge passage 23.
The refrigerant gas in the discharge chamber 3b is discharged and sprayed into the oil separation hole 22a. The discharge passage 23 is oriented toward the eccentric position of the oil separation hole 22a having a circular cross section, and
The refrigerant gas discharged from No. 3 is blown to the oil separation hole 22a along the peripheral surface of the oil separation hole 22a. Mist-like oil is mixed in the refrigerant gas, and this oil is used as the oil separation hole 22a.
It is separated from the refrigerant gas by spraying the refrigerant gas on the. The discharged refrigerant gas flows out from the discharge port 1c to the external refrigerant circuit, and the separated oil remains in the oil separation hole 22a. Oil separation hole 22
The bottom portion of a is communicated with the lubricating passage 11a of the lip seal 11 via the oil passage 24. A throttle 24 a is provided in the oil passage 24. The lubrication passage 11a communicates with the crank chamber 2a through the gap of the radial bearing 8.

The stroke of the single-headed piston 20 changes depending on the pressure difference between the pressure in the crank chamber 2a and the suction pressure in the cylinder bore 1b through the single-headed piston 20. That is, the tilt angle of the swash plate 15 that affects the compression capacity changes. The pressure in the crank chamber 2a is controlled by the control valve 25 attached to the lower portion of the rear housing 3.

As shown in FIG. 2, the valve housing 26 constituting the control valve 25 is provided with a discharge pressure introducing port 26a, a suction pressure introducing port 26b and a control port 26c. The discharge pressure introducing port 26a is opened to the discharge chamber 3b, and the suction pressure introducing port 26b is formed in the suction pressure introducing passage 27.
Through the suction chamber 3a. Control port 26c
Communicates with the crank chamber 2a through the control passage 28.

The inner end wall of the valve housing 28 and the valve body 29
A return spring 30 is interposed between and, and the valve element 29 receives the spring action of the return spring 30 in the direction of closing the valve hole 26d. When the valve hole 26d is closed, the discharge pressure introducing port 2
The communication between 6a and the control port 26c is cut off.

A diaphragm 31 is interposed on the outer end wall side of the valve housing 26. Valve housing 26
A pressing rod 32 is slidably housed therein so as to always shut off the suction pressure introducing port 26b and the control port 26c. One end of the pressing rod 32 has a diaphragm 3
It is fastened to 1. A pressing spring 33 is interposed between the outer end wall of the valve housing 26 and the diaphragm 31. The pressing spring 33 opposes the suction pressure via the diaphragm 31, and the pressing rod 32 is always in contact with the valve body 29 by the spring action of the pressing spring 33. That is, the control valve 2
5 is the valve body 2 in accordance with the fluctuation of the suction pressure that reflects the cooling load.
The valve opening of No. 9 is adjusted, and the pressure in the crank chamber 2a is automatically adjusted according to the fluctuation of the suction pressure. This pressure adjustment controls the tilt angle of the swash plate 15.

Switching bodies 34A and 34B are provided in the cylindrical body 12.
Is slidably accommodated, and the switching body 34A,
A ball 35 is interposed between 34B. The small-diameter inner end portion 7a of the rotating shaft 7 is fitted into the cylindrical body 12, and the gas vent passage 7b extends from the peripheral surface of the rotating shaft 7 to the end surface 7 of the small-diameter inner end portion 7a.
It is laid all the way to a ₁ . The small diameter portion 34a at the front end of the switching body 34A has a gas vent passage 7b in the small diameter inner end portion 7a.
To the rotary shaft 7. The rotary shaft 7 and the tip of the small diameter portion 34a cannot rotate relative to each other, and the switching body 34A rotates integrally with the rotary shaft 7.

A switching return spring 36 is provided between the step 34b of the switching body 34A and the step 7b ₁ of the gas vent passage 7b.
And the switching bodies 34A and 34B are urged toward the rear housing 3 side.

As shown in FIGS. 4 and 8, the switching body 34
An annular withdrawal groove 34c is recessed in the large diameter portion of A.
The cylindrical body 12 has a plurality of protruding / retracting holes 12a (three in this embodiment).
Are arranged in the circumferential direction. The projecting / retracting hole 12a has a taper shape in which the diameter decreases from the inner peripheral surface of the cylindrical body 12 toward the outer peripheral surface thereof, and a retaining ball 37 is housed in each of the projecting / retracting hole 12. The diameter D of the holding ball 37 is larger than the thickness T of the cylindrical body 12 and smaller than the sum (T + H) of the thickness T of the cylindrical body 12 and the depth H of the retract groove 34c. The minimum diameter of the protruding / retracting hole 12a on the outer peripheral surface of the cylindrical body 12 is smaller than the diameter D of the holding ball 37, and the holding ball 37 can project from the protruding / retracting hole 12a by (DT). The swash plate support 1 is located at a position where the inclination angle of the swash plate 15 is zero.
4 is the front side of the front end face 14a.

An accommodating hole 1a ₂ in the cylinder block 1 accommodating the cylindrical body 12 penetrates to the rear housing 3 side,
A valve housing 41 is fitted and fixed in the accommodation hole 1a ₂ . A valve seat 42 and a ball valve 43 are housed in the valve housing 41. The closing spring 4 is provided between the spring seat 44 fixed to the valve housing 41 and the valve seat 42.
5 is interposed. The ball valve 43 receives the spring action of the closing spring 45 in the direction of closing the valve hole 41a on the valve housing 41, and the valve housing 41 and the valve seat 4
An on-off valve that opens and closes the pressure passages 41b and 46 together with the valve 2.

The small-diameter end portion 34d of the switching body 34B is pressed against the back portion of the valve seat 42 by the spring action of the switching return spring 36. The accommodation hole 1a ₂ communicates with the crank chamber 2a via the pressure passage 46.

As shown in FIG. 5, a discharge pressure region 3b ₁ extends from the discharge chamber 3b at the radial center of the rear housing 3, and a part of the valve housing 41 discharges pressure from the accommodating hole 1a _2. It projects to the region 3b ₁ . The valve hole 41a communicates with the discharge pressure region 3b ₁ via the pressure passage 41b.

At the radial center of the rear housing 3, an electromagnetic solenoid 47 serving as driving means for forcibly changing the tilt angle is arranged. A tilt angle compulsory changing spring 48 is interposed between the fixed iron core 47b and the movable iron core 47c which are excited by energization of the coil 47a. When the electromagnetic solenoid 47 is excited, the movable iron core 47c overcomes the spring force of the tilt angle forced change spring 48 and is attracted to the fixed iron core 47b. Movable range of the movable iron core 47c is regulated between a position abutting the end wall position and the solenoid housing 47d abuts against the fixed iron core 47b, the distance L ₁ from the ball valve 43 is a valve hole 41a
Can be separated only.

A push rod 49 is fixed to the movable iron core 47c. The pressing rod 49 slidably passes through the valve housing 41, and the front end of the pressing rod 49 has a valve hole 4
It has entered into the valve housing 41 through 1a.

Switching bodies 34A, 34B, balls 35,
The valve seat 42, the ball valve 43 and the pressing rod 49 are integrated by the spring action of the switching return spring 36 and the tilt angle changing spring 48 with respect to the movement of the rotary shaft 7 and the cylindrical body 12 in the axial direction. In this integrated state, when the electromagnetic solenoid 47 is excited, the switching body 34A moves to the rear housing 3 side by the spring action of the switching return spring 36. By this movement, the step 34b is separated from the end surface 7a ₁ of the rotating shaft 7, and the retreat groove 34c is aligned with the arrangement position of the projecting / retracting holes 12a.

When the electromagnetic solenoid 47 is demagnetized, the switching body 34A moves to the rotary shaft 7 side by the spring action of the tilt angle forced change spring 48. This movement causes a step 3
4b comes into contact with the end surface 7a ₁ , and the retreat groove 34c is provided in the retractable hole 12
It deviates from the array position of a.

A linear degassing passage 34e is formed in the axial direction on the peripheral surface of the switching body 34A. A linear gas vent passage 34f is formed in the axial direction on the peripheral surface of the switching body 34B, and an annular gas vent passage 34g is formed. The degassing passage 34e starts from the step 34b and communicates with the gap 50 between the switching bodies 34A and 34B. Accordingly, in a state in which the stepped 34b and the end face 7a ₁ is in contact is cut off from communicating with the gas vent passage 7b and the gas vent passage 34e. The gas vent passage 34f connects the gap 50 and the gas vent passage 34g, and the gas vent passage 34g passes through the accommodation hole 1a ₁ and the gas vent passage 51, and the suction chamber 3a.
Is in communication with.

A rotation detector 5 is provided in the front housing 2.
2 are installed. The rotation detector 52 is the rotation support 18
Is detected, and this detection signal is sent to the control computer C. The control computer C has a rotation detector 52.
When the rotation stop detection signal is obtained from, the demagnetization of the electromagnetic solenoid 47 is commanded.

An inlet 1d for introducing the refrigerant gas into the suction chamber 3a and an outlet 1c for discharging the refrigerant gas from the discharge chamber 3b.
And are connected by an external refrigerant circuit 53. A condenser 54, an expansion valve 55 and an evaporator 56 are provided on the external refrigerant circuit 53. The expansion valve 55 controls the refrigerant flow rate according to the fluctuation of the gas pressure on the outlet side of the evaporator 56.

A temperature sensor 57 is installed on the outlet side of the evaporator 56. The temperature sensor 57 detects the temperature on the outlet side of the evaporator 56, and this detection signal is sent to the control computer C. When the control computer C obtains the temperature detection information below the predetermined temperature from the temperature sensor 57, the control computer C commands the demagnetization of the electromagnetic solenoid 47.

An air conditioner operation switch 58, an air conditioner stop switch 59, an accelerator switch 60 and an outside air temperature sensor 61 are signal-connected to the control computer C. The control computer C commands the excitation of the electromagnetic solenoid 47 by turning on the air conditioner operation switch 58 and turning off the accelerator switch 60. In addition, the control computer C
The demagnetization of the electromagnetic solenoid 47 is commanded by turning on the air conditioner stop switch 59 and the accelerator switch 60. Further, the control computer C commands the demagnetization of the electromagnetic solenoid 47 when the temperature detection information below the predetermined temperature is obtained from the outside air temperature sensor 61.

In the state of FIG. 1, the air conditioner operation switch 58
Is ON and the electromagnetic solenoid 47 is in an excited state. In the energized state of the electromagnetic solenoid 47, the ball valve 43 closes the valve hole 41a as shown in FIG. 8, and the high pressure refrigerant gas in the discharge pressure region 3b ₁ is not supplied to the crank chamber 2a. Further, the step 34b of the switching body 34A is separated from the end surface 7a ₁ of the rotary shaft 7, and the crank chamber 2a and the suction chamber 3
a is a gas vent passage 7b, 34e, 34f, 34g, 5
Connect by 1. Further, the holding ball 37 is provided with the retracting groove 3
4c and is retracted from the outer peripheral surface of the cylinder 14,
The slide of the swash plate support 14 is not obstructed by the holding balls 37. Therefore, the pressure in the crank chamber 2a is controlled by the control valve 25, and the swash plate tilt angle is variably controlled according to the suction pressure that reflects the cooling load.

That is, the diaphragm 31 is displaced according to the fluctuation of the suction pressure introduced from the suction pressure introducing port 26a, and this displacement is transmitted to the valve body 29 via the pressing rod 32. When the suction pressure is high (the cooling load is large), the diaphragm 31 bends and deforms in the direction away from the valve body 29 against the spring action of the pressing spring 33, and the valve opening degree of the valve body 29 decreases. When the pressure in the crank chamber 2a is higher than the suction pressure, the refrigerant gas in the crank chamber 2a flows into the suction chamber 3a via the gas vent passages 7b, 34e, 34f, 34g, 51. Therefore, when the valve opening degree of the valve element 29 is reduced, the pressure in the crank chamber 2a is reduced and the swash plate inclination angle is increased. On the contrary, when the suction pressure is low (the cooling load is small), the diaphragm 31 is bent and deformed toward the valve body 29 by the spring action of the pressing spring 33, and the valve opening of the valve body 29 increases. Therefore, the pressure in the crank chamber 2a rises and the swash plate inclination angle becomes smaller.

The control computer C has a rotation stop detection signal from the rotation detector 52, a detection signal below a predetermined temperature from the temperature sensor 57, and an ON state from the air conditioner stop switch 59.
The electromagnetic solenoid 47 is demagnetized based on the signal, the ON signal from the accelerator switch 60, or the detection signal from the outside air temperature sensor 61 at a predetermined temperature or lower. That is, each of these detection signals becomes a zero tilt angle command signal for the electromagnetic solenoid 47. The rotation detector 52, the temperature sensor 57, the air conditioner stop switch 59, the accelerator switch 60 or the outside air temperature sensor 61 serves as an external control signal generator.

When the electromagnetic solenoid 47 is demagnetized, the movable iron core 47c is separated from the fixed iron core 47b by the spring action of the tilt angle forced change spring 48 and abuts against the end wall of the solenoid housing 47d. By the movement of the movable iron core 47c, the ball valve 43, the valve seat 42, and the switching bodies 34B and 34A are integrally pushed toward the rotation support body 18 side. Swash plate support 1
When 4 is not at the position where the swash plate tilt angle is zero, the holding ball 37 cannot project from the outer peripheral surface of the cylindrical body 12. That is,
The position of the holding ball 37 in the retreat groove 34c is determined by the swash plate support 1
This is the position where 4 slides are allowed.

By the time the small step 34c ₁ between the retracting groove 34c and the large-diameter peripheral surface of the switching body 34A presses the holding ball 37, the switching bodies 34A, 34B and the ball valve 43 are in the state of FIG. 8 to the state of FIG. Can be moved to a distance L ₂ (<L ₁ ). Therefore, the ball valve 43 is separated from the valve hole 41a by the distance L ₂ , and the ball valve 43 opens the valve hole 41a. Due to this valve opening, the high pressure refrigerant gas in the discharge pressure region 3b ₁ flows into the crank chamber 2a via the pressure passages 41b and 46. Further, the steps 7b ₁ and 34b come into contact with each other, and the gas vent passage 3
4e is cut off. Due to this interruption, the gas vent passages 7b, 34e, 34f, 34 between the crank chamber 2a and the suction chamber 3a.
The communication via g and 51 is cut off.

Gas vent passages 7b, 34e, 34f, 34
The pressure in the crank chamber 2a rapidly rises to the discharge pressure due to the interruption of g and 51 and the inflow of high-pressure refrigerant gas, and the inclination angle of the swash plate 15 is 0 ° due to the rapid pressure increase in the crank chamber 2a as shown in FIG. Becomes That is, the swash plate support 14 is moved and arranged at a position where the swash plate inclination angle is zero against the spring action of the capacity return spring 40. Therefore, the discharge capacity becomes zero, and a state similar to the compressor no-load state when the clutch is disengaged in the clutch-mounted compressor can be obtained. When the compressor load becomes zero, the full output of the vehicle engine is directed to drive the vehicle.

The swash plate support 14 is placed at a position where the tilt angle of the swash plate becomes zero.
Then, the holding ball 37 is released from the covering action of the swash plate support 14 and can project from the retractable hole 12a. The switching body 34A is further urged toward the rotation support body 18 by the spring action of the inclination angle changing spring 48. Therefore, as shown in FIG.
Riding on the large-diameter peripheral surface of the switching body 34A from the
2a. The swash plate support body 14 at the position where the swash plate inclination angle is zero is prevented from moving toward the rotation support body 18 side by the holding ball 37 protruding from the projecting / retracting hole 12. That is, the position of the holding ball 37 protruding from the projecting / retracting hole 12a is a zero tilt holding position for holding the swash plate support 14 at a position where the swash plate tilt angle is zero.

Then, the holding ball 37 and the switching body 34
A, 34B and the ball 35 serve as a zero tilt holding means for holding the swash plate support 14 at a position where the swash plate tilt angle is zero. That is,
The switching bodies 34A and 34B and the ball 35 are arranged at a normal position where the swash plate support 14 is allowed to slide by the excitation of the electromagnetic solenoid 47. Also, the switching bodies 34A, 3
4B and the ball 35 are arranged at a regulation position for holding the swash plate supporter 14 at a position where the tilt angle of the swash plate is zero due to the demagnetization of the electromagnetic solenoid 47.

If the state where the swash plate tilt angle is zero where the discharge capacity is zero continues, the pressure in the compressor becomes uniform and the crank chamber 2
The tilt angle of the swash plate 15 cannot be maintained at zero only by the pressure inside the a. However, the swash plate support 14 is prevented from moving toward the rotation support 18 by the holding balls 37 protruding from the projecting / retracting hole 12a, and the swash plate tilt angle does not return arbitrarily.

The lip seal 53 prevents the refrigerant gas from leaking from the crank chamber 2a along the peripheral surface of the rotary shaft 7. When the swash plate inclination angle is brought to zero, the pressure in the crank chamber 2a rapidly rises to the discharge pressure, and this high pressure state continues for a while. If such a high pressure state continues, the sealing performance of the lip seal 53 will relatively deteriorate, and refrigerant gas leakage may occur. However, the oil supplied from the oil separation hole 22a through the oil passage 24 lubricates the lip seal 11 to enhance the sealing performance. Therefore, even if the pressure in the crank chamber 2a becomes a high pressure equivalent to the discharge pressure, the refrigerant gas does not leak from between the lip seal 11 and the rotating shaft 7. The oil used to lubricate the lip seal 11 flows back to the crank chamber 2a.

Even if the compressor is operated with the swash plate 15 having an inclination angle of 0 °, the discharge capacity becomes zero, so that the refrigerant gas pressure in the compressor and in the external refrigerant circuit becomes uniform. for that reason,
The swash plate 15 cannot be tilted by lowering the pressure in the crank chamber 2a. In this embodiment, the swash plate 15 is tilted by exciting the electromagnetic solenoid 47.

When the air conditioner operation switch 58 is ON, the control computer C causes the temperature sensor 57 to detect a signal of a predetermined temperature or higher, and the accelerator switch 60 to set O.
The electromagnetic solenoid 47 is excited based on the FF signal or the detection signal from the outside air temperature sensor 61 which is equal to or higher than the predetermined temperature.
That is, these detection signals become tilt angle return command signals. Due to the excitation of the electromagnetic solenoid 47, the movable iron core 47c is attracted to the fixed iron core 47b against the spring action of the tilt angle forced change spring 48. Due to this adsorption, the switching bodies 34A, 34B and the ball valve 43 are moved to the rear housing 3 side by the spring action of the switching return spring 36, and the retreat groove 34c is aligned with the arrangement position of the retractable holes 12a. Therefore, the holding ball 37
Can fall into the retreat groove 34c, and the swash plate support 14
Is released from the movement blocking action of the holding ball 37. The swash plate support 1 released from the movement blocking action of the holding balls 37
Reference numeral 4 denotes the rotary support 1 by the spring action of the capacity return spring 40.
Then, the swash plate 15 is tilted. Therefore, the single-headed piston 20 starts to reciprocate, and the discharge action is performed.

It is the high pressure supply to the crank chamber 2a by demagnetization of the electromagnetic solenoid 47 that forcibly changes the inclination angle of the swash plate 15 to zero. The inclination angle of the swash plate 15 is restored by stopping the high pressure supply to the crank chamber 2a by the excitation of the electromagnetic solenoid 47 and the action of the capacity return spring 40. Further, the holding ball 37 for holding the swash plate support 14 at the position where the inclination angle of the swash plate 15 is zero is due to the switching operation of the switching body 34A accompanying the excitation / demagnetization of the electromagnetic solenoid 47. That is, the swash plate tilt angle is maintained at zero and the swash plate tilt angle is restored only by the excitation / demagnetization of the electromagnetic solenoid 47 for forcibly changing the swash plate tilt angle to zero. Therefore, unlike the case of the clutchless compressor disclosed in Japanese Patent Laid-Open No. 3-143725, which requires a solenoid valve for making the swash plate tilt angle zero and a solenoid valve for returning the swash plate tilt angle, The size and weight of the compressor are not increased.

When the electromagnetic solenoid 47 is demagnetized, the holding ball 37 prevents the swash plate support 14 from moving due to the spring action of the capacity return spring 40. Therefore, the holding ball 37 is sandwiched between the switching body 34A and the swash plate support 14. This sandwiched state is the switching body 34.
When A is moved to the rear housing side, that is, the holding ball 3
It becomes a resistance when releasing the movement blocking effect of 7. In this embodiment, a part 34e of the gas vent passages 7b, 34e, 34f, 34g, 51 for adjusting the pressure in the crank chamber 2a.
Is provided between the switching body 34A and the cylindrical body 12 so as to intersect the retreat groove 34c. With such a gas vent passage structure, the lubricating oil mixed in the refrigerant gas lubricates the peripheral surface of the switching body 34A and the holding balls 37, and the lubricity between the switching body 34A and the holding balls 37 is enhanced. Therefore, the resistance at the time of releasing the movement preventing action of the holding ball 37 is reduced. Further, in the present embodiment, a pair of switching bodies 34A, 34B are used to interlock the holding ball 37 with the opening / closing operation of the ball valve 43. ing. Both switching bodies 34A and 34B may be formed of a single member. However, by adopting a separate structure as in this embodiment, the switching body 34B does not rotate integrally with the rotary shaft 7 and the cylindrical body 12, and the contact portion of the valve seat 42 with the switching body 34B is eliminated. Wear is avoided. If the abrasion of the contact portion is increased, the holding ball 37 may be out of the retracted state, and the swash plate support 14 may not be held at the position where the swash plate tilt angle is zero.

In the present embodiment, the rotation detector 52, the temperature sensor 57, the air conditioner stop switch 59, the accelerator switch 60, and the outside air temperature sensor 61 are used to control the excitation / demagnetization of the electromagnetic solenoid 47 that drives the tilt angle forced change. It is used as an external control signal generator. However, in addition to these, for example, a pressure sensor that detects the refrigerant gas pressure or a cooling water temperature sensor of a vehicle engine is also a target of the external control signal generator. When the detected pressure obtained from the pressure sensor is out of the predetermined upper and lower limits, the electromagnetic solenoid 4
7 is demagnetized and the inclination angle of the swash plate 15 is made zero. When the detected pressure is within the specified upper and lower limits, the electromagnetic solenoid 4
7 is excited to restore the tilt angle of the swash plate 15.

The present invention is, of course, not limited to the above-mentioned embodiment, but the embodiments shown in FIGS. 9 and 10 are also possible. A control valve 63 is provided at the radial center of the rear housing 3.

The internal structure of the control valve 63 will be described with reference to FIG. A coil 65 and a fixed iron core 66 are housed and fixed in the solenoid housing 64. A guide rod 67 is slidably pierced and supported on the central axis of the fixed iron core 66. A movable iron core 68 is fixed to the guide rod 67 and can be brought into contact with and separated from the fixed iron core 66 by the guide action of the guide rod 67. The movable range of the movable iron core 68 is restricted between the fixed iron core 66 and the spring bearing 64a of the solenoid housing 64. Guide rod 67
A spring bearing 67a is formed at one end of the valve, and a valve opening forcing spring 69 is interposed between the spring bearing 67a and the end wall 64b of the solenoid housing 64. Movable iron core 6
8 is a fixed iron core 6 due to the spring action of the valve opening forced spring 69.
It is urged in a direction away from 6.

A valve housing 70 is coupled and fixed to the solenoid housing 64, and the valve housing 7
A spherical valve element 71 is housed in the zero. The valve housing 70 is provided with a discharge pressure introducing port 70a, a suction pressure introducing port 70b, and a control port 70c. The discharge pressure introducing port 70a communicates with the discharge chamber 3b via a discharge pressure introducing passage 72, and the suction pressure introducing port 70b communicates with the suction chamber 3a via a suction pressure introducing passage 73.
The control port 70c is connected to the crank chamber 2 via the pressure passage 74.
It communicates with a.

The small-diameter end portion 34d of the switching body 34B is in contact with the valve body 71 through the discharge pressure introducing port 70a. A return spring 75 is interposed between the end wall of the valve housing 70 and the valve body 71, and the valve body 71 has a valve hole 70d.
The return spring 75 receives the spring action in the direction of closing the valve. When the valve hole 70d is closed, the communication between the discharge pressure introducing port 70a and the control port 70c is cut off.

A diaphragm 76 is interposed between the solenoid housing 64 and the valve housing 70. A pressing rod 77 is slidably accommodated in the valve housing 70 so as to always shut off the suction pressure introducing port 70b and the control port 70c. Push rod 7
One end of 7 is fixed to the diaphragm 76. A pressing spring 78 is interposed between the spring receiver 64a and the diaphragm 76. The pressure spring 78 opposes the suction pressure via the diaphragm 76. The pressing rod 77 is the pressing spring 7.
The spring action of 8 always makes contact with the valve body 71.

When the valve body 71 closes the valve hole 70d and the movable iron core 68 is in contact with the fixed iron core 66,
The guide rod 67 is slightly separated from the diaphragm 76. When the coil 65 is demagnetized, the movable iron core 68 contacts the spring receiver 64a by the spring action of the valve opening forced spring 69. In this contact state, the guide rod 67
Pushes the pressing rod 77 toward the valve body 71 side,
The maximum valve opening is.

In the state of FIG. 1, the coil 65 is energized and the fixed iron core 66 is in the excited state. In the excited state of the fixed iron core 66, the movable iron core 68 is attracted to the fixed iron core 66, and the guide rod 67 is separated from the diaphragm 76. Under this separated state, the diaphragm 76 is displaced according to the fluctuation of the suction pressure introduced from the suction pressure introducing port 70b, and this displacement is caused via the pressing rod 77.
It is transmitted to 1. High suction pressure (high cooling load)
In this case, the diaphragm 76 is bent and deformed toward the guide rod 67 side against the spring action of the pressing spring 78, and the valve opening degree of the valve body 71 is reduced. When the valve opening degree of the valve body 71 is reduced, the pressure in the crank chamber 2a is reduced and the swash plate inclination angle is increased. On the contrary, when the suction pressure is low (the cooling load is small), the diaphragm 76 is flexibly deformed toward the valve body 71 side by the spring action of the pressing spring 78, and the valve opening degree of the valve body 71 increases. Therefore, the pressure in the crank chamber 2a rises and the swash plate inclination angle becomes smaller.

When the energization of the coil 65 is stopped, the movable iron core 68 is moved by the spring action of the valve opening forcing spring 69 to fix the fixed iron core 6.
It separates from 6 and contacts the spring receiver 64a. The movement of the movable iron core 68 maximizes the valve opening of the valve body 71, and the pressure in the crank chamber 2a rapidly increases. Crank chamber 2
The inclination angle of the swash plate 15 immediately becomes 0 ° due to the rapid pressure increase in a. Then, the switching body 34A moves to the rotary support 18 side in conjunction with the movement of the valve body 71 to the maximum valve opening position,
The holding balls 37 project from the withdrawal holes 12a. Due to this protrusion, the swash plate support 14 is held at a position where the swash plate tilt angle is zero.

The control valve 63 of this embodiment has both the function of the control valve 25 of the above-mentioned embodiment and the function of the electromagnetic solenoid 47, and it is more remarkable to avoid the size increase and weight increase of the compressor.

Further, in the present invention, a hydraulic actuator is used instead of the electromagnetic solenoid 47 as the drive means for forcibly changing the tilt angle, and the oil is supplied to and stopped from the hydraulic actuator by an electromagnetic three-way valve or an electromagnetic on-off valve. Other embodiments are also possible.

Further, in the present invention, the capacity return spring 40 is omitted, and the swash plate which is tiltably supported by the swash plate support 14 receives the centrifugal action in the tilt increasing direction by its rotation. Is also possible. For example, if the center of gravity of the entire swash plate 15, the connecting pieces 16A, 16B and the guide pins 17A, 17B is set in a region of the swash plate support 14 closer to the rotary support 18 than the spherical center and to the support arm 18a, The rotation of the swash plate 15 causes a centrifugal action in the direction of increasing the tilt angle. Such a center of gravity structure serves as a biasing means for returning the tilt angle of the swash plate.

[0068]

As described above in detail, according to the present invention, the inclination angle changing valve is interposed on the inclination angle changing pressure passage for connecting the crank chamber and the discharge pressure region, and the zero inclination angle is provided on the rotary shaft. The zero tilt holding means and the on-off valve provided with the zero tilt holding body that is switched between the holding position and the slide allowance position are switched and driven by the tilt forcibly changing drive means, and the swash plate tilt angle becomes zero on the rotary shaft. Since the swash plate support at the position is urged in the direction of increasing the swash plate tilt angle by the swash plate tilt angle restoring biasing means, the operation of the tilt angle forced change drive means for forcibly changing the swash plate tilt angle to zero The swash plate tilt angle zero holding and the swash plate tilt angle returning are also performed by only this, and there is an excellent effect that the zero capacity can be reliably held without increasing the size and weight of the compressor.

[Brief description of drawings]

FIG. 1 is a side sectional view of an entire compressor according to an embodiment of the present invention.

FIG. 2 is an enlarged side sectional view showing an on-off valve and a control valve.

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

FIG. 4 is a sectional view taken along line BB in FIG.

5 is a cross-sectional view taken along the line CC of FIG.

6 is a cross-sectional view taken along the line DD of FIG.

FIG. 7 is a side sectional view showing a state where the discharge volume is zero.

FIG. 8 is an enlarged side sectional view of an essential part showing a state where the on-off valve is closed.

FIG. 9 is an enlarged side sectional view of an essential part showing a state where the ball valve is slightly separated from the valve hole.

FIG. 10 is an enlarged side sectional view of an essential part showing a state where the ball valve is maximally separated from the valve hole.

FIG. 11 is a side sectional view of the entire compressor showing another example.

FIG. 12 is an enlarged side sectional view of a main part.

[Explanation of symbols]

2a ... Crank chamber, 3b ₁ ... Discharge pressure area, 7 ... Rotating shaft,
12 ... Cylindrical body that is a part of the rotating shaft, 14 ... Swash plate support, 1
5 ... Swash plate, 20 ... Single-headed piston, 34A, 34B ... Switching body that constitutes zero tilt angle holding means, 37 ... Holding ball that serves as zero tilt angle holding body, 40 ... Capacity return spring that serves as biasing means for swash plate tilt angle , 41b ... pressure passage for forcibly changing the tilt angle,
46 ... Pressure passage for forced inclination change, 47 ... Electromagnetic solenoid serving as drive means for forced tilt change, 63 ... Control valve serving as drive means for forced tilt change of another example.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shoho Sonobe, 2-chome Toyota-cho, Kariya city, Aichi Stock company, Toyota Industries Corporation (72) Inventor Ken Mizuto 2-chome, Toyota-cho, Kariya city, Aichi prefecture Stock company Toyota Automatic Loom Works (72) Inventor Toshiro Fujii 2-chome Toyota Town, Kariya City, Aichi Prefecture Toyota Automatic Loom Works

Claims (3)

[Claims] 1. A swash plate support on a rotating shaft in a housing that defines a crank chamber, a suction chamber, a discharge chamber, and a cylinder bore connecting these chambers, and accommodates a single-head piston in a reciprocating linear motion in the cylinder bore. Is slidably supported, the swash plate is tiltably supported on the swash plate support, and the swash plate is tiltably linked to the rotary support on the rotating shaft.
In a one-sided piston type variable displacement compressor that controls the tilt angle of the swash plate by the difference between the pressure in the crank chamber and the suction pressure via a single-headed piston, the crank chamber and the discharge pressure region are connected, and A pressure passage for forcibly changing the tilt angle that supplies the pressure for moving the swash plate support to the position where the plate tilt angle is zero from the discharge pressure region to the crank chamber, and a tilt angle forcibly changing the pressure passage for forcibly changing the tilt angle. Opening / closing valve, a zero tilt holding position for holding the swash plate support at a position where the swash plate tilt angle is zero on the rotation shaft, and a slide allowance position for allowing the swash plate support to slide on the rotation shaft. And a zero tilt angle holding means provided with a zero tilt angle holding body and a zero tilt angle command signal output from an external control signal generator. Hold the holder The drive means for forcibly changing the tilt angle for switching from the id allowable position to the zero tilt holding position and the swash plate support at the position where the tilt angle of the swash plate is zero on the rotation axis are attached in the direction of increasing the tilt angle of the swash plate. A clutchless structure for a one-sided piston type variable displacement compressor including a swash plate tilt angle urging means for urging. 2. The zero tilt angle holding means is switchably arranged between a slide permitting position which is recessed in the outer peripheral surface of the cylindrical body which is a part of the rotary shaft and a zero tilt angle holding position which projects from the outer peripheral surface of the cylindrical body. It comprises a zero tilt holding body and a switching body housed in the tubular body so as to interlock with the opening / closing operation of the on-off valve, and the switching body can immerse the zero tilt holding body in the outer peripheral surface of the tubular body. 2. The clutchless in the one-sided piston variable displacement compressor according to claim 1, wherein the clutchless in the one-sided piston type variable displacement compressor is switched between a normal position and a regulation position that regulates the zero tilt holding body to a zero tilt holding position that projects from the outer peripheral surface of the tubular body. Construction. 3. The clutchless structure for a one-side piston type variable displacement compressor according to claim 1, wherein the biasing means for returning the tilt angle of the swash plate is a spring member.