JP3089775B2 - Variable capacity compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of cylinders, a suction chamber, a crank chamber, a discharge chamber, a rotating shaft extending into the crank chamber, and a variable inclination angle with respect to the rotating shaft. a rotary drive plate that is disposed so as to be rotated by the rotary shaft, and reciprocates within said respective cylinder by rocking of the rotary drive plate takes in suction fluid in the suction chamber, the discharge and compression a piston out ejection into the chamber, the crank chamber pressure adjustment to the controls the inclination angle of the rotary drive plate, that Yusuke <br/> the discharge capacity control means for varying the discharge fluid volume variable displacement compressor It is about.

[0002]

2. Description of the Related Art As a discharge capacity control means in a conventional swinging swash plate type variable displacement compressor, the following (1) to (1) are described.
The one shown in (4) has been proposed.

(1) A pressure regulating valve disclosed in Japanese Patent Application Laid-Open No. 63-17667 includes a valve section for controlling opening and closing of a communication passage between a crank chamber and a suction chamber, and a pressure sensing section for controlling opening and closing of the valve section. A control valve mechanism having an output conduction rod that is loosely inserted into the pressure sensing section to restrict the movement of the valve section and restrict the communication path between the crank chamber and the suction chamber in a closed state. An actuator is provided in the control valve mechanism.

(2) A pressure regulating valve disclosed in Japanese Patent Application Laid-Open No. 61-55380 discloses a first valve element for opening and closing a communication path between a discharge chamber and a crank chamber, and a communication path between the suction chamber and the crank chamber. And a second valve element that opens and closes the first valve element. The first valve element is configured to be opened and closed by an electromagnetic solenoid to open when the solenoid is turned off and to close when turned on. The second valve body is opened and closed by a pressure sensing member that senses the pressure in the suction chamber, and opens when the pressure in the suction chamber is equal to or higher than a predetermined set value and closes when the pressure in the suction chamber is equal to or lower than a predetermined set value. The first valve element and the second valve element are connected to each other by an urging member that urges both of the valve elements in a valve closing direction, so that the pressure is sensed when the solenoid is turned on. In the direction in which the second valve element opens with respect to the member. There none so as to act, and configured to be able to vary the set value of the suction chamber pressure by further changing the electric current value to the solenoid.

(3) A control valve mechanism disclosed in JP-A-59-150988 has a spool valve having a spool that can be displaced so as to selectively communicate a crank chamber with one or both of a suction chamber and a discharge chamber; A solenoid device that operates so that the spool of the spool valve is displaced in the direction of communication between the crank chamber and the suction chamber when energized, and the spool of the spool valve is cranked by an urging force that changes according to the inclination angle of the swinging swash plate. It comprises a feedback mechanism that operates so as to be displaced in a direction that allows communication between the chamber and the discharge chamber, and electronic means that biases the solenoid as needed.

(4) Japanese Patent Application Laid-Open No. 62-247186
The control valve mechanism disclosed in Japanese Patent Application Laid-Open Publication No. H11-157572 is provided in the middle of a first communication hole that connects the crank chamber and the suction chamber, and is operated by an external input signal to open the communication hole and connect the crank chamber to the suction chamber. A pressure provided in the middle of a second communication passage communicating the operation control device with the crank chamber and the suction chamber for opening and closing the second communication passage so as to sense the pressure in the crank chamber and keep the pressure in the crank chamber substantially constant; Operation control device.

[0007]

All of the above-mentioned conventional pressure control mechanisms (1) to (3) physically link an external force or an electromagnetic solenoid to a valve portion, a second valve body or a spool valve. With such a configuration, an external force or a relatively large force is required for the electromagnetic solenoid, and there is a problem that the external force driving unit becomes large and heavy. or,
As the size of the electromagnetic solenoid increases, the current required for the solenoid increases, and the heat generated during operation increases. As a result, the housing of the compressor is heated, and as a result, the efficiency of the compressor decreases.

Further, the pressure control mechanism of the prior art (4) is as follows:
Since the first valve element or the second valve element is used independently, when the external operation control device is operated, the first valve element is switched to the second valve element.
There is a problem that proper control cannot be performed because the action of the valve element is reduced or promoted.

A first object of the present invention is to provide an external hydraulic control valve small, the variable capacity compressor that can be reduced in weight. A second object of the present invention, in addition to the first object, is to suppress an abnormal increase in pressure in a crank chamber when an external operation control valve is opened, and to perform compression.
It is to provide a variable capacity compressor that can be used to improve the durability of the machine.

[0010]

According to the first aspect of the present invention,
In order to achieve the first object, the discharge capacity control means in the variable displacement compressor includes a first communication path communicating the discharge chamber with the crank chamber, a second communication path communicating the crank chamber with the suction chamber, An external operation control valve that is operated by an input signal to open the first communication passage and communicate the discharge chamber and the crank chamber, and a third valve that senses the pressure in the crank chamber and the suction pressure to maintain the suction pressure substantially constant. A pressure-operated control valve for opening and closing the two-way passage; and, when the first operation passage is opened by operating the externally-operated control valve, closing the second communication passage by discharge pressure; An opening / closing valve that opens the second communication passage by an elastic member when the first communication passage is closed by the opening / closing valve.
While the second communication passage is open, the pressure operation control valve
Discharge fluid volume control that reflects the cooling load
You.

[0011] Further, an invention according to claim 2, wherein, in order to achieve the second object, a third communication passage communicating the crank chamber and the suction chamber provided in claim 1, clan to said third communication path < is released when the pressure in the work chamber rises above a set value,
A measure is taken to provide a pressure actuated control valve having a throttle that is closed by an elastic member when the pressure falls below a set value.

[0012]

According to the first aspect of the present invention, when the external operation control valve is opened and the first communication passage is opened, high-pressure fluid in the discharge chamber is supplied into the crank chamber through the communication passage, and the piston is opened. The pressure acting on the back of the swash plate increases, the inclination angle of the swash plate decreases, and the discharge capacity decreases. At this time, by opening the first communication passage, the discharge pressure causes the second communication passage connecting the crank chamber and the suction chamber to be shut off by the opening / closing valve, and the influence by the pressure operation control valve, that is, the pressure operation control valve is opened. Also in this case, the fluid flows from the crank chamber to the suction chamber, and the rise of the crank chamber pressure is prevented from being delayed. On the other hand, when the second communication passage is opened by the on-off valve,
In the case, the cooling load was reflected by the pressure operation control valve.
The discharge fluid volume control is performed.

Since the second communication passage is closed by an on-off valve utilizing the discharge pressure, the external drive mechanism operating the external operation control valve changes the control valve to the pressure in the second communication passage. Therefore, it is possible to set a small driving force required to open the external driving mechanism, and the external driving mechanism can be reduced in size and weight.

According to a second aspect of the present invention, in addition to the function of the first aspect, the external operation control valve is opened and abnormally high pressure is applied from the discharge chamber to the crank chamber through the first communication passage. When the fluid is supplied, the pressure opens the pressure operation control valve provided in the third communication passage to open the third communication passage, and the fluid gradually flows from the throttle to the suction chamber side, and the pressure in the crank chamber is reduced. The pressure is prevented from rising abnormally and the compressor
It is possible to enhance the durability.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. A front housing 3 forming a crank chamber 2 is fixedly joined to a front end surface of the cylinder block 1. A rear housing 5 is joined and fixed to a rear end surface of the cylinder block 1 via a valve plate 4. Further, pistons 6 are respectively accommodated in a plurality of cylinder bores 1 a formed in the cylinder block 1, and refrigerant is provided to a valve plate 4 from a suction chamber 7 formed in a rear housing 5 by reciprocation of the piston 6. The air is sucked into the cylinder bore 1 a through the hole 8 and is discharged from the discharge hole 9 to the discharge chamber 10.

A rotary shaft 11 is rotatably supported at the center of the cylinder block 1 and the front housing 3 by the power of the engine. A rotary support 12 is fitted and fixed in the crank chamber 2 of the rotary shaft 11, and a rotary drive plate 14 is provided on the rotary support 12 via a connecting pin 13 so as to be capable of swinging in a longitudinal direction. It is supported along. A cylindrical sleeve 15 is fitted on the rotary shaft 11 so as to be slidable in the front-rear direction.
Is connected to the boss 14a of the rotary drive plate 14 by a pair of pins 16 (only one is shown in FIG. 1). Also, the inclined surface of the rotary drive plate 14 and the boss 14a
A swinging swash plate 17 is mounted on the outer periphery so as to be rotatable relative to the rotation driving plate 14 and swingable in the front-rear direction. The swinging swash plate 17 is connected to each of the pistons 6 via a piston rod 18. I have. The swing swash plate 17 is supported so as to be swingable in the front-rear direction and non-rotatably along a guide rail 19 fixed to the cylinder block 1 and the front housing 3.

The pressure Pd of the suction chamber or the discharge chamber acts on the working surfaces of the plurality of pistons 6 which perform compression in the cylinder bore 1a, and the pressure Pc in the crank chamber 2 acts on the back surface of the piston 6. The pressure difference between the working surface and the back surface acting on each piston 6 causes the piston rod 1
Moment <br/> bets to a rotary drive plate 14 via the 8及beauty swash plate 17 acts in response to this pressure difference, the discharge capacity of the compressed refrigerant gas inclination angle of the rotary drive plate 14 is changed Adjusted.

Next, a description will be given of the ejection capacity control means which is a main part of the present invention. The discharge chamber 10 and the crank chamber 2
The first communication passage 21 communicating the crank chamber 2 and the suction chamber 7 is also provided in the cylinder block 1 and the valve plate 4.
And the valve plate 4. A spool chamber 23 is formed in the first and second communication passages 21 and 22 so as to communicate the two communication passages with each other. And
In the spool chamber 23, a first spool valve 24 for opening and closing the first communication passage 21 and a second spool valve 25 as an opening and closing valve for opening and closing the second communication passage 22 can reciprocate synchronously by a connecting rod 26. Is housed in A position regulating member 28 is connected to an upper portion of the first spool valve 24 via a support rod 27, and the position of the position regulating member 28 is regulated by a stopper 29 provided in the spool chamber 23. The end of the second spool valve 25 is provided with the spool valve 2.
5 is urged toward the stopper 29 side, and the first communication passage 21 is always closed by the first spool valve 24 and the second communication passage 22 is opened by the second spool valve 25. Have been. The second spool valve 25
Is formed with a communication path 25a that always opens the second communication path 22. Further, a communication passage 28 a for applying a discharge pressure Pd to the end face of the first spool valve 24 is formed in the position regulating member 28.

An electromagnetic control valve 31 as an external operation control valve for opening and closing the first communication passage 21 is accommodated in the discharge chamber 10. The control valve 31 includes a housing case 32 fixed to the rear housing 5 and the first communication passage 2 with respect to the case.
1, a valve body 33 for opening and closing the opening of the discharge chamber 10 side, a spring 34 for constantly biasing the valve body 33 in the closing direction, and an opening direction for pushing the valve body 33 against the biasing force of the spring 34. And a solenoid coil 35 that can operate.

A pressure actuation control valve 36 is housed in the second communication passage 22. The control valve includes a storage case 37 housed inside the cylinder block 1, a bellows 38 having one end attached to the case, a valve body 39 attached to the other end of the bellows 38, and a valve body 39. Seat 4
And a coil spring 42 housed in a closed space 41 in the bellows 38 so as to press against the zero valve hole 40a. The pressure Ps in the suction chamber 7 acting on the valve body 39 and the pressure Ps in the crank chamber 2 acting on the bellows 38
The valve 39 is opened and closed based on the pressure difference from the pressure c, and the pressure Ps in the suction chamber 7 is maintained at a predetermined pressure.

Next, the operation of the variable displacement compressor configured as described above will be described. Now, as shown in FIGS. 1 and 2, the first communication passage 21 is provided by the valve body 33 of the electromagnetic control valve 31.
Of the first spool valve 24 is closed.
As a result, the first communication passage 21 is closed in the spool chamber 23, and the second communication passage 2 is closed by the second spool valve 25.
When the rotating shaft 11 is rotated in a state in which the rotating swash plate 17 is opened, the swinging swash plate 17 is swung in the front-rear direction by the rotating support 12, the connecting pin 13, and the rotation driving plate 14, and is moved through the piston rod 18. The piston 6 is reciprocated back and forth in the cylinder bore 1a, and the refrigerant is sucked from the suction chamber 7 into the cylinder bore 1a, compressed, and then discharged to the discharge chamber 10.

During this operation, the second communication passage 22
The pressure Ps in the suction chamber 7, which fluctuates due to the cooling load condition of the compressor, acts on the valve body 39 of the pressure operation control valve 36, and the pressure Pc in the crank chamber 2. Acts on the bellows 36. Therefore, for example, when the cabin temperature rises and the cooling load increases, and the suction pressure Ps rises, the bellows 38 resists the urging force of the spring 42 due to the suction pressure Ps acting on the valve body 39. , The refrigerant gas in the crank chamber 2 is reduced to the suction chamber 7 through the second communication passage 22, the pressure Pc in the crank chamber 2 decreases, and the swing swash plate 17 and the rotation
The inclination angle of the rotary drive plate 14 is increased, and the discharge capacity is increased. Conversely, when the cabin temperature decreases and the cooling load decreases, and the suction pressure Ps decreases, the valve body 39 is operated in the closing direction by the urging force of the spring 42, and thus the second communication passage 22 is closed. Then, the pressure Pc in the crank chamber 2 rises, and the inclination angles of the swinging swash plate 17 and the rotary drive plate 14 are reduced,
Discharge capacity is reduced.

When the running speed of the vehicle is rapidly accelerated, it is necessary to reduce the power of the compressor to reduce the rotational load acting on the engine. At this time, in order to reduce the displacement of the compressor, when the rotation speed becomes equal to or higher than a predetermined rotation speed by a sensor for detecting the rotation speed of the engine or the like, the electromagnetic control valve 31 is energized from a control device (not shown). Then, as shown in FIG. 3, the valve element 33 opens the first communication path 22, and the high-pressure refrigerant from the discharge chamber 10 acts on the first spool valve 24 via the first communication path 21. 24, the first communication passage 21 is opened against the urging force of the spring 30, and the second spool valve 25 is moved in a direction to close the second communication passage 22. Therefore, the pressure Pc in the crank chamber 2 is increased by the high-pressure refrigerant supplied from the first communication passage 21, the differential pressure acting on the front and rear surfaces of the piston 6 is increased, and the swash plate 17 reduces the discharge capacity. Moved in decreasing direction. Therefore, the rotational load acting on the engine from the compressor due to sudden acceleration of the vehicle is reduced. At this time, since the second communication path 22 is closed by the second spool valve 25, even if the cooling load is high and the pressure operation control valve 36 is in the open state as shown in FIG. The high-pressure refrigerant supplied into the crank chamber 2 from 21 does not flow into the suction chamber 7 through the second communication path 22, and as a result, the switching to the discharge capacity reduction direction can be quickly performed.

In the first embodiment, the electromagnetic control valve 31 is simply a coil or a coil for generating a force necessary to separate the valve body 33 from the opening end face of the first communication passage 21 on the discharge chamber 10 side. Since the current is sufficient, the electromagnetic control valve 31 can be reduced in size and weight, and the electromagnetic control valve 31 can be reduced.
, The heating of the rear housing 5 can be suppressed, and the compression efficiency can be increased.

Next, a second embodiment of the present invention will be described with reference to FIGS. In this compressor, in addition to the configuration of the compressor of the first embodiment described above, a third communication passage 45 for communicating the crank chamber and the suction chamber is provided in the cylinder block 1 and the valve plate 4, and the third communication passage is provided. A second pressure operation control valve 46 is provided in the middle of 45. As shown in FIG. 5, the control valve 46 has a valve housing chamber 4 inside a housing case 47.
8 and a valve plate 48b formed at the end of the valve hole 48a.
The spool 50 interlocked with the ball valve 49 is always urged by a spring 51 as an elastic member in a direction to close the valve hole 48a. When the ball valve 49 is opened due to the abnormal pressure in the crank chamber 2 by the throttle 50 a provided in the spool 50, the high-pressure refrigerant gas in the crank chamber 2 is supplied to the suction chamber 7 through the third communication passage 45. To be reduced to When the high-pressure refrigerant in the discharge chamber 10 is abnormally supplied into the crank chamber 2 from the first communication path 21 by opening the electromagnetic control valve 31, the excessive pressure acting on the back surface of the piston 6 causes The piston rod 18 pulls the rocking swash plate 17 rightward in FIG.
An abnormal pressing force is prevented from acting on the connecting portion with the connecting member 7 to reduce wear of the sliding portion of both members and improve durability.

The present invention is not limited to the above embodiment, and as shown in FIG.
The bellows 52 is provided between the tip end of the bellows and the stopper 29, and a coil spring 53 is interposed in the bellows 52 so that the second communication path 22 is always kept open by the spring 30. When the control valve 31 is opened, the bellows 52 may sense the discharge pressure Pd, and the second spool valve 25 may be moved in a direction to close the second communication passage 22. Also, the second spool valve 2
The position of 5 is changed between the pressure-operated control valve 36 and the suction chamber 7, or various control valves opened and closed by external operating means are used in place of the electromagnetic control valve 31. The configuration of each unit may be arbitrarily changed and embodied without departing from the spirit of the invention.

[0027]

As described above in detail, the first aspect of the invention has the effect that the external operation control valve for controlling the displacement of the compressor can be reduced in size and weight.

According to a second aspect of the present invention, in addition to the effect of the first aspect, when the pressure in the crank chamber rises due to the operation of the external operation control valve, the pressure in the crank chamber becomes abnormal. and prevented from rising to an effect capable of improving the durability of the compressor.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a central portion showing a first embodiment of a variable displacement compressor according to the present invention.

FIG. 2 is a partially enlarged explanatory view of a state in which an external operation control valve is closed.

FIG. 3 is a partially enlarged explanatory view of an external operation control valve in an open state.

FIG. 4 is a vertical sectional view of a central portion showing a second embodiment of the present invention.

FIG. 5 is a partially enlarged sectional view of the vicinity of a second pressure operation control valve.

FIG. 6 is a partial sectional view showing another embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 1 cylinder block, 1a cylinder bore, 2 crank chamber, 3 front housing, 5 rear housing, 6 piston, 7 suction chamber, 8 suction hole, 10 discharge chamber, 11 rotation shaft, 12 rotation support, 14 rotation drive plate, 17 swing Dynamic swash plate, 21 first communication passage, 22 second communication passage, 23 spool chamber, 24 first spool valve, 25
A second spool valve as an on-off valve, 30 a spring as an elastic member, 31 an electromagnetic control valve as an external operation control valve,
33 valve body, 36 pressure operated control valve, 45 third communication passage, 46 pressure operated control valve, 49 ball valve, 50 spool, 50a throttle, 51 spring as an elastic member.

Continuation of the front page (56) References JP-U 1-71177 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F04B 27/08 F04B 27/14

Claims (2)

(57) [Claims] A plurality of cylinders, a suction chamber, a discharge chamber, a crank chamber, a rotating shaft extending into the crank chamber, and a tilt angle with respect to the rotating shaft that can be changed and rotated by the rotating shaft. A rotary drive plate arranged so that
A piston that reciprocates in each of the cylinders to take in the fluid sucked into the suction chamber, compresses and discharges the fluid into the discharge chamber, and adjusts the pressure in the crank chamber by swinging the rotary drive plate. In a variable displacement compressor having a displacement control means for controlling a tilt angle of a driving plate and changing a discharge fluid capacity, the discharge capacity control means includes a first communication passage communicating the discharge chamber with a crank chamber, and a crank chamber. And the second that communicates with the suction chamber
A communication passage, an external operation control valve that is operated by an external input signal to open the first communication passage and communicate the discharge chamber and the crank chamber, and detects the crank chamber pressure and the suction pressure to substantially reduce the suction pressure. A pressure-operated control valve for opening and closing the second communication passage so as to keep it constant, and further, when the external operation control valve is operated to open the first communication passage, closing the second communication passage by discharge pressure; and When the first communication passage is closed by the external operation control valve, the second communication passage is closed by an elastic member.
An on-off valve for opening a communication passage , wherein the on-off valve opens the second communication passage.
Is a discharge reflecting the cooling load by the pressure operation control valve.
Variable displacement compressor with fluid displacement control . 2. The method of claim 1 provided with a third communication passage communicating the crank chamber and the suction chamber, is opened when the pressure in the crank chamber to said third communication path rises above the set value, the set value or less variable capacity compressor provided with a pressure actuated control valve having a diaphragm which is closed by the elastic member when it becomes.