JPS61145379A - Variable displacement compressor - Google Patents

Abstract

PURPOSE:To perform a displacement control while preventing working fluid from being heated, by both providing an oil pump in the shaft of a swash plate type compressor and operating this oil pump with its delivery pressure acting on the other end of a sleeve urging its one end by a spring and connecting with a tilt plate. CONSTITUTION:If the pressure in a suction pressure chamber 45 decreases while a swash plate type compressor is in operation, a diaphragm 41 in a displacement control valve extends by action of a spring 46, and a valve unit 40 is detected from a valve seat 39. In this way, delivery oil of an oil pump 28, formed on a driving shaft 5, is allowed to flow into a pressure chamber 13 through a small hole 38, valve hole and an oil passage 32. The pressure chamber 13 is both arranged on the driving shaft and formed in a rotary part 8 by a flange 11a in one end side of a sleeve 11 connected with a tilt turning lever 18 of a swash plate 16, and the pressure chamber, if its pressure increases to a high level, decreases a tilt angle of the swash plate by moving the sleeve leftward.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a variable capacity compressor, and is effective for use as a refrigerant compressor in, for example, an automobile air conditioner.

(Prior art) A type of compressor in which a swash plate attached to a shaft at an inclined angle swings as the shaft rotates, and a piston reciprocates in response to this swinging motion (referred to as a wobble type). In this case, the displacement is varied by changing the inclination angle of the swash plate using the discharge fluid pressure of the compressor and moving the bottom dead center of the piston. An example of such a device is Japanese Patent Application Laid-open No. 158384/1984.

(Problem to be solved by the invention) However, in the conventional system, the discharge fluid (discharge refrigerant) used to change the inclination angle of the swash plate is returned to the suction side, and the fluid returned to the suction side Since the fluid is recompressed, the discharge temperature of the fluid discharged from the compressor increases. As a result, the temperature near the discharge port also rises, and the heat is also transmitted to rubber products such as the shaft seal portion, causing a problem of deterioration of performance.

(Means for Solving the Problems) The present invention aims to solve the above problems and takes the following measures. In other words, there is a housing that forms the outer shape of the compressor and has a cylinder inside, a shaft that is rotatably supported by the housing and rotates in response to an external driving force, and a shaft that is arranged so as to cover the outer circumference of the shaft and that is arranged on one side. a sleeve that moves in the axial direction under pressure from the shaft; a swash plate that is connected to the sleeve at an angle of inclination with respect to the axis of the shaft; a piston that reciprocates;
an oil chamber formed in the housing, an oil pump that receives the rotational force of the shaft to suck in and discharge oil from the oil chamber, and guides the oil discharged from the oil pump to one end surface of the sleeve. (The variable capacity compressor is equipped with an oil passage and a valve means for opening and closing communication of the oil passage, and the inclination angle of the swash plate is increased or decreased by moving the sleeve.

(Function) In the present invention, the hydraulic pressure discharged from the oil pump is applied to one end surface of the sleeve to move the sleeve.

This changes the angle of inclination of the swash plate connected to the sleeve with respect to its axis, resulting in a change in the stroke of the piston and a change in displacement. Further, it is determined whether or not the oil discharged from the oil pump is made to act on one end surface of the sleeve by the valve means.

(Effects of the Invention) As described above, in the present invention, the inclination angle of the swash plate is not changed by using discharge fluid, but by the discharge oil discharged from the oil pump, so the temperature of the discharge fluid discharged from the compressor is This can prevent the problem of rising temperatures.

In addition, as the compressor rotation speed increases, the oil pump's discharge capacity increases and the discharge hydraulic pressure increases.Even if the valve means is opened at the same degree, the hydraulic pressure guided to one end surface of the sleeve increases. There is also feedback that the machine capacity decreases as the rotation speed increases.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a diagram showing a longitudinal section of this embodiment. Compressor 10
A flange portion 1a is formed on a housing 1 having an outer shape of 0, and a pulley 3 is disposed on the outer periphery of the flange portion 1a via a bearing 2.

This pulley 3 rotates in response to an external driving force, and by energizing the coil 4, the clutch plate 5 is connected to the brake lJ3, and the rotational force of the pulley 3 is transmitted to the shaft 6 connected to the clutch plate 5. Ru.

A bearing protrusion 1b is formed inside the housing 1,
An outer ring of a bearing 7 is fixed to this bearing protrusion 1b.

A rotating member 8 is fixed to the inner ring of the bearing 7, and this rotating member 8 rotates integrally with the shaft 6 passing through the rotating member 8. This rotating member 8 and the flange portion 1a
A shaft seal member 9 is arranged between the rotating member 8 and
An O-ring 10 is disposed between the shaft 6 and the shaft 6.

A recess 8a is formed in the center of the rotating member 8, and a flange 11a of a cylindrical sleeve 11 that covers the outer periphery of the shaft 6 is slidably disposed within the recess 8a. An O-ring 12 is attached to the outer periphery of this flange portion 11a.
is arranged to maintain a seal with the inner wall of the recess 8a, and a pressure chamber 13 is formed between the bottom surface of the recess 8a and the flange 11a. A spring 14 is disposed at the end of the sleeve 11 opposite to the flange portion 11a,
This spring 14 is stopped by a spring receiver 15 fixed to the shaft 6, and the sleeve 11
is urged toward the pressure chamber 13 (to the right in the figure).

In the sleeve 11, with respect to the axis of the shaft 6,
A disc-shaped swash plate 16 is arranged with an inclination angle α. FIG. 3 is a sectional view taken along the line ■-■ in FIG. It fits into the spherical recesses 1 and 1b provided on the sides of 11. In this way, the swash plate 16 and the sleeve 11 are connected to the swash plate 16.
are connected in such a way that the angle of inclination can be changed. Said swash plate 1
A fixing pin 17 is provided protruding from one side of the rotary member 6, and this fixing pin 17 is fitted into a guide groove 18a of a stay 18 provided on the rotating member 8. On the other hand, a pedestal 20 is arranged on the other side of the swash plate 16 via a thrust bearing 19, and these are fixed by a retaining ring 21.

A cylinder block 23 having five cylinders 22 is housed inside the housing 1 . A piston 24 is slidably inserted into each of the cylinders 22 while maintaining a sealing property, and each piston 24 is connected to the pedestal 20 by a connecting rod 25. A stopper 26 is disposed at the connecting portion between the connecting rod 25 and the pedestal 20 to prevent the connecting rod 25 from coming off the pedestal 20.

One end surface of the shaft 6 is rotatably supported by the cylinder block 23 via a bearing 27, and an oil pump 28 (
In this embodiment, a trochoid pump is used as the oil pump). The oil pump 28 is housed in the center of the cylinder block 23, with a suction chamber 29 on the front side (right side in the figure) and a discharge chamber 30 on the rear side (left side in the figure). are formed respectively. An oil chamber 31 for storing oil is formed in the housing 1, and the oil chamber 31 and the suction chamber 29 are connected to an oil suction passage 313.31b formed in the cylinder block 23.

31c. An oil passage 32 is bored in the center of the shaft 6 to guide the oil discharged into the discharge chamber 30 into the pressure chamber 13; It is opened and closed by a valve means 33. Note that the suction chamber 29 and the oil passage 32 communicate with each other through a narrow road 52.

The valve means 33 has an outer shape formed by a case 34,
The inside of this case 34 is divided into a pressure detection chamber 36 by a partition member 35.
and a valve chamber 37. - This valve chamber 37 communicates with the discharge chamber 30 through a communication hole 38 formed in the case 34, and an oil passage 32 formed in the shaft 6 opens into this valve chamber 37. A valve member 39 is disposed within the valve chamber 37 between the communication hole 38 and the opening end of the oil passage 32, and the valve body 40 is seated on the valve seat member 39, thereby connecting the oil passage 32 and the valve member 39. Communication with the discharge chamber 30 is cut off. The pressure detection chamber 36 is located in the rear housing 43
It communicates with a low pressure chamber 45 through a communication passage 44 bored in the pressure detection chamber 36, and a bellows frame 4 which is freely expandable and retractable is provided in the pressure detection chamber 36.
I is stored.

The bellow flamm 41 is connected to the valve body 4 via a valve stem 42.
0 is connected, and the valve element 40 is further urged in the valve opening direction by a spring 46 disposed within the bellows flamm 41.

A side plate 47 is disposed on the side surface of the cylinder block 23 to cover the open end of the cylinder 22, and the side plate 47 has an inlet 48 for each cylinder 22. A discharge port 49 is provided. Furthermore, a rear housing 43 fixed to the housing 1 with bolts 50 is fixed to the side of the side plate 47, and the intake port 48 is fixed to the rear housing 43.
is a low pressure chamber 45 and a high pressure chamber 51 in which the discharge port 49 opens.
is formed. This low pressure chamber 45 is connected to an evaporator (not shown) in the refrigeration cycle, and the high pressure chamber 51 is connected to a condenser (not shown). Further, the suction port 48.
Each discharge port 49 has a suction valve.

A discharge valve (both not shown) is provided. FIG. 2 is a cross-sectional view of FIG. They are communicated through a passage 53.

Next, the operation of this embodiment will be explained. The driving force from the prime mover (car engine) not shown is Boo1J3
．． It is transmitted to the shaft 6 via the clutch 5, and when the shaft 6 rotates, the swash plate 16 starts a rocking motion. The piston 2 receives this oscillating movement of the diagonal vi, 16.
4 reciprocates within the cylinder 22, and the refrigerant in the low pressure chamber 45 is sucked in through the suction port 48, compressed, and discharged into the high pressure chamber 51 through the discharge port 49. The oil pump 28 is also rotating, and the oil in the oil chamber 31 is pumped through the oil suction passages 31a, 31b,
31c into the suction chamber 29, and then discharged into the discharge chamber 30. However, since the valve means 33 is closed, the oil discharged into the discharge chamber 30 is transferred to the oil return passage 5.
3 and is returned to the oil chamber 31. At this time, the swash plate 16
The inclination angle α is minimum and the compressor operates at maximum capacity.

Next, when the pressure in the low pressure chamber 45 decreases due to a reduction in the cooling load, an increase in the engine speed, and an excessive cooling capacity of the compressor, the pressure in the detection chamber 36 also decreases, causing the bellows flammable 41 expands due to the differential pressure between the inside and outside and the biasing force of the spring 46.

This movement is then transmitted to the valve body 40 via the valve stem 42, and the valve body 40 is separated from the valve seat member 39. Then, the oil discharged into the discharge chamber 30 flows into the valve chamber 37 through the communication hole 38 and is further led to the pressure chamber 13 through the oil passage 32. As a result, the pressure inside the pressure chamber 13 increases, this pressure is received by the flange portion 11a of the sleeve 11, and the sleeve 11
moves to the left in the figure against the biasing force of the spring 14.

Then, the swash plate 16 connected to the sleeve 11 and further fixed at one point by the fixing pin 17 and the stay 18 gradually increases its inclination angle α. As a result, the stroke of the piston 24 becomes shorter and the displacement of the compressor decreases.

Next, a second embodiment of the present invention will be described. FIG. 4 is a longitudinal sectional view of the second embodiment. In this embodiment, a solenoid valve 60 is used as the valve means for opening and closing the oil passage 32. This solenoid valve 60 has a conventionally well-known structure, and when the coil 61 is energized, the valve body 40, which is a moving core, moves to the stator core 62.
The oil is drawn to the side, and is separated from the valve seat member 39, thereby communicating the oil passage 32 and the discharge chamber 30.

Note that when the coil 61 is not energized, the valve body 40 is closed by the biasing force of the spring 63.

The other operations of the configuration 1 are the same as those of the previous embodiment, and the capacity of the compressor is controlled by controlling the energization and de-energization (ON-OFF) of the coil 61.

FIG. 5 is a diagram showing the system of this embodiment, with reference numeral 10 in the figure.
0 is a compressor, 102 is a condenser, 103 is a receiver, 104 is an evaporator, 105 is a blower, 106 is a control circuit, 107 is an evaporator outlet air temperature sensor, and 1O8 is an expansion valve. Control circuit 106
In response to the signal from the evaporator outlet air temperature sensor 107, the solenoid valve 60 is turned OFF as shown in FIG.

Even if the solenoid valve is ON, if the evaporator outlet air temperature further decreases, the clutch 5 is turned on as shown in Fig. 6.
to prevent evaporator frost.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view of an embodiment of the present invention.
-n sectional view, Figure 3 is a mm-m sectional view of Figure 1, Figure 4 is a longitudinal sectional view of the second embodiment, Figure 5 is a system diagram of the second embodiment, and Figure 6 is the second embodiment. It is a control explanatory diagram of an example. DESCRIPTION OF SYMBOLS 1... Housing, 6... Shaft, 11... Sleeve, 13... Pressure chamber, 16... Swash plate, 22...
- Cylinder, 24... Piston, 28... Oil pump, 31... Oil chamber, 32... Oil passage.

Claims (1)

[Claims] A housing that forms the outer shape of the compressor and has a cylinder inside; a shaft that is rotatably supported by the housing and rotates by receiving an external driving force; a swash plate connected to the sleeve at an inclined angle with respect to the axis of the shaft; and a swash plate connected to the swash plate and reciprocated within the cylinder according to the movement of the swash plate. A moving piston, an oil chamber formed in the housing, an oil pump that sucks in and discharges oil from the oil chamber in response to the rotational force of the shaft, and the oil discharged from the oil pump to the oil chamber. A variable capacity compressor, comprising an oil passage leading to one end surface of a sleeve, and a valve means for opening and closing communication of the oil passage, and in which the inclination angle of the swash plate is increased or decreased by movement of the sleeve.