JPH0353473B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a variable displacement wobble plate compressor used for compressing refrigerant gas in a vehicle air conditioner.

(Prior Art and its Problems) Conventionally, a variable capacity rocking plate compressor is provided with a solenoid valve that opens and closes a communication passage between a suction chamber and a crank chamber, and by controlling the opening degree of the solenoid valve, the suction chamber and the crank chamber are connected to each other. It is known that the inclination angle of the rocking plate is adjusted by adjusting the degree of communication with the crank chamber and changing the pressure in the crank chamber, and the piston stroke is changed to vary the discharge capacity. There is. However, in a compressor with such a configuration, if the solenoid valve is controlled only by the output of the temperature setting device,
As a characteristic of the compressor, the suction pressure changes depending on the heat load, and the pressure loss between the evaporator and the compressor suction port causes the effective evaporation pressure of the refrigerant to fluctuate, causing the evaporator to freeze or There was a problem that the cooling capacity required for the air conditioner could not be obtained.

(Object of the invention) The present invention has been made in view of the above problems, and
It is an object of the present invention to provide a variable capacity oscillating plate compressor that can obtain a desired cooling capacity by correcting the opening degree of a solenoid valve in response to changes in heat load.

(Structure of the Invention) In order to achieve the above object, the present invention provides a valve body having a pressure receiving surface that opens and closes a communication path between a suction chamber and a crank chamber and receives pressure in the suction chamber; The suction chamber is controlled by a pressure regulating valve having a pressure responsive body that controls the opening degree of the valve body according to the magnitude of the current supplied to the solenoid, and an electromagnetic actuator that controls the opening degree of the valve body according to the magnitude of the current supplied to the solenoid. The variable displacement type is configured such that the degree of communication between the crank chamber and the crank chamber is adjusted, the inclination angle of the rocking plate is adjusted by changing the pressure in the crank chamber, and the piston stroke is changed to vary the discharge displacement. The wobble plate compressor is characterized by comprising a correction means for detecting a change in thermal load and correcting the magnitude of the current supplied to the electromagnetic actuator in accordance with the change.

(Embodiment of the Invention) An embodiment of the present invention will be described below based on the drawings.

FIGS. 1 and 2 show the overall configuration of a variable displacement wobble plate compressor.

In the figure, 1 is a housing, and the housing 1 includes a cylindrical case 2, a cylinder head 4 airtightly attached to one end surface of the case 2 (the left end surface in the figure) via a valve plate 3, and the case 2. 2 and a head member 5 airtightly attached to the other end surface (right end surface in the figure) of the head member 2.

The cylinder head 4 has a flat, substantially cylindrical shape, and one end surface is closed. A pressure regulating valve 60 (described later) is disposed in the center thereof, and a suction chamber 41 is provided around the outer periphery of the pressure regulating valve 60. A discharge chamber 46 is further formed around the outer periphery of the suction chamber 41.
The suction chamber 41 and the discharge chamber 46 are substantially annular and concentric, and are defined by the other end surface of the cylinder head 4 in airtight contact with one end surface of the valve plate 3 via a sealing member.

The suction chamber 41 is connected to the outlet of the evaporator (not shown) of the refrigerant cycle of the air conditioner through a suction port (not shown), and the discharge chamber 46 is connected to the condenser (not shown) of the refrigerant cycle through a discharge port (not shown). (not shown).

A piston mechanism 20 for compressing refrigerant is disposed inside the case 2 located on the other end side of the valve plate 3. The piston mechanism 20
is composed of a cylinder block 21 and a piston 22.

The cylinder block 21 is integrally formed inside the case 2, and is provided with a center hole 21a for fitting a drive shaft of a piston drive mechanism 50, which will be described later, along the center axis. A plurality of cylinders 23 are arranged in the cylinder block 21 at predetermined intervals in the circumferential direction with axes parallel to the central axis.

The piston 22 is slidably fitted into each cylinder 23. Moreover, the piston 2
A piston rod 24 is bored in the piston rod 2, and the piston rod 24 has a ball joint 24a at the tip.
is provided.

Note that the valve plate 3 includes the suction chamber 4.
A plurality of suction ports 42 are provided to communicate between the discharge chamber 46 and the inside of each cylinder 23, and a plurality of discharge ports 44 are provided to communicate between the discharge chamber 46 and the inside of each cylinder 23. A discharge valve 45 and a discharge valve stop 45a are provided at the open end of the discharge port 44 of the discharge chamber 46 (see FIG. 2). Further, the suction port is also provided with a suction valve (not shown).

In this way, the piston mechanism 20
The low-pressure refrigerant in the cylinder 1 is sucked into the cylinder 23 through the suction port 42 and the suction valve, and compressed by the piston 22 to become high-temperature and high-pressure refrigerant.
The liquid is discharged into a discharge chamber 46 via a discharge valve 45.

In order to drive the piston mechanism 20, a drive mechanism 50 is disposed within the crank chamber 26 at the other end of the housing 1. The drive mechanism 50 includes:
A drive shaft 25 disposed along approximately the central axis of the housing 1, an arm member 52 fitted to the other end of the drive shaft 25, and an arm member 52 disposed on the outer periphery of the approximately intermediate portion of the drive shaft 25 in the axial direction. The slider 54 includes a slider 54 and a swing plate 55 disposed around the outer periphery of the slider 54.

The drive shaft 25 has one end connected to the cylinder block 2.
The arm member 5 is rotatably supported in the center hole 21a of the head member 5 via a ball bearing 27, and the portion on the other end side from the axially intermediate position is attached to the inner peripheral surface of the head member 5.
2 and a large diameter ball bearing 57 sequentially. The other end of the drive shaft 25 passes through the center hole 5a of the head member 5 and extends outward, and the output shaft side pulley of the vehicle engine and a drive belt (not shown) are connected to the extended end. A magnetic clutch (not shown) connected by is attached. A mechanical seal 58 is interposed between the boss portion 52a of the arm member 52 and the center hole 5a of the head member 5, and an O-ring is provided between the drive shaft 25 and the arm member 52. The inside of the crank chamber 26 is kept airtight.

On the other hand, the slider 54 has a sleeve shape and is fitted on the drive shaft 25 so as to be slidable in the axial direction but not rotatable in the circumferential direction, so that the slider 54 rotates together with the drive shaft 25. There is. Further, an internal slider 54a is fitted inside the drive shaft 25.
The internal slider 54a is pressed toward the cylinder block 21 by a coil spring 33 fitted within the drive shaft 25. A cross pin 54 passes through the internal slider 54a in the diametrical direction.
Both ends of b pass through mutually opposing slots 25a, 25a of the drive shaft 25, and are connected to the slider 54.
is connected to. Therefore, the oscillating plate 55 is biased by the coil spring 33 together with the internal slider 54a to decrease the inclination angle. Furthermore,
The swing plate 55 has a disk shape and is disposed on the outer periphery of the slider 54 at an approximately intermediate portion in the axial direction as follows. That is, the swing plate 55 has a center hole loosely fitted into the slider 54, and both sides of the swing plate 55 are rotatably connected to the slider 54 via trunnion pins 59. In this way, the swing plate 55 is configured to be displaced within a predetermined angle range with respect to the vertical plane about the trunnion pin 59 as an axis.

Further, the swing plate 55 and the arm member 52 are connected as described below. As shown in FIG. 2, a parallel guide portion 55a is provided at a predetermined position on the end surface of the swing plate 55 on the side of the arm member 52, protruding in the radial direction, and a pin protruding from the parallel guide portion 55a is provided. 55b
and a pin 52 protruding from the side surface of the tip end of the arm member 52.
A coil spring 36 is stretched between the coil spring 36 and b. Further, a cam surface 52c at the tip of the arm member 52 is engaged with an end surface of the swing plate 55.

Furthermore, each piston 2 is provided on one end surface of the swing plate 55.
2, piston rod 24, ball joint 24
a are connected to each other. In this way, the drive mechanism 5
0, the piston mechanism 2 is rotated by the rotation of the rocking plate 55.
0 piston 22 is made to slide. In addition, the swing plate 55 is operated by the pressure inside the crank chamber 26, the biasing force of the coil spring 33, and the cylinder 23.
The angle of inclination with respect to the vertical plane changes depending on the difference between the internal pressure (reaction force of the piston 22), and the stroke of the piston 22 is increased or decreased by changing the angle of inclination.

In order to adjust the pressure in the crank chamber 26 and control the inclination angle of the rocking plate 55, a pressure regulating valve 6 is provided.
0 is located centrally within the cylinder head 4. The pressure regulating valve 60 has a cylindrical case 61 fitted into holes 4a and 21b formed at the axes of the cylinder head 4 and cylinder block 21. In this case, it is fixed by screwing into the front end hole 21d.

As shown in FIG. 3, the pressure regulating valve 60 has a communication port 21c between the suction chamber 41 and the crank chamber 26, which is formed at the axis of the cylinder block 21.
The valve body 62 has a pressure receiving surface 62a that opens and closes and receives the pressure in the suction chamber 41, and a current value supplied based on an external signal (status signal from a solar radiation sensor, mix door sensor, temperature sensor, etc.). As a result, the solenoid 63 is energized, which causes the movable iron core 64 to
is a coil spring 6 that urges the movable iron core 64.
5 and an electromagnetic actuator 68 that operates to approach a fixed iron core 66 to control the opening degree of the valve body 62 via a transmission rod 67, which will be described later. The opening degree of the valve body 62 is determined by the spring force (coil spring 65, bellows 78) and the pressure inside the suction chamber 41 when no current is supplied to the solenoid 63, that is, when the electromagnetic actuator is off. open high). In addition, when current is supplied to the solenoid 63, that is, when the electromagnetic actuator is turned on, the attraction force of the fixed iron core 66, the change in the spring force, and the suction chamber 4 change depending on the current value supplied to the solenoid 63.
Depends on the pressure within 1.

As described above, the transmission rod 67 is located between the valve body 62 and the movable iron core 64, and transmits the mutual displacement between them, and at the same time transmits the displacement between the two when the movable iron core 64 is most attracted to the fixed iron core 66. Core 64 and fixed iron core 6
It has a function to set the positional relationship (gap x) with 6. Such a transmission rod 67 is connected to the fixed iron core 6
It is composed of an iron core rod 67a located on the 6 side, a valve rod 67b located on the valve body 62 side, and a connecting rod 67c that connects them.The connecting rod 67c has one end connected to the shaft of the iron core rod 67a. Press fit into the hole 67d formed in the core and connect the other end to the valve side rod 67.
The iron core rod 67a and the valve rod 67b are connected by press-fitting into a hole 67e formed in the axis of the iron core 67a. The iron core side rod 67a is slidably fitted into a hole 66b formed at the axial center of the fixed iron core 66, and the valve side rod 67b is slidably fitted into a hole 69a formed at the axial center of the support plate 69. Fitted.

Note that a recess 61 is provided at the front end axis of the case 61.
b, and the support plate 6 is formed in the recess 61b.
9 and a bottomed valve body housing cylinder 72 is fitted therein. Bellows 7 covering support plate 69 and transmission rod 67
8 and the valve body 62 are made into an integral subassembly by brazing (or soldering) or the like.

The bottom wall 72a of the valve body housing cylinder 72 has a gasket 73.
Through the communication port forming wall 2 of the cylinder block 21
1e, and a hole 72b formed at the axis of the bottom wall 72a is connected to the communication port 21c. The valve body 62 is slidably fitted into the valve body housing cylinder 72 and opens and closes the hole 72b. The refrigerant flowing into the valve body housing cylinder 72 from the hole 72b flows through a plurality of holes 72 formed in the peripheral wall of the valve body housing cylinder 72.
c flows into the suction chamber 41 via a passage (not shown).

Further, the coil spring 65 that biases the movable iron core 64 has its mounting seat 74 screwed onto the screw shaft 75, so that the spring force can be changed by changing the set position of the mounting seat 74. There is.

In the figure, 76 is an O-ring that maintains airtightness between the case 61 and the support plate 69, and 77 is a cable that supplies current to the solenoid 63.

FIG. 5 shows a current control circuit 80 for controlling the opening degree of the pressure regulating valve 60. A temperature sensor 81 that detects heat load such as outside air temperature or capacitor temperature is connected in series with a temperature setting device 82 provided in the vehicle interior, and the other end of the temperature setting device 82 is connected to a constant voltage source 83. . The positive input terminal of the comparator 84 of the current control circuit 80 is connected between the connection terminal of the temperature sensor 81 and the temperature setting device 82. The current control circuit 80 is connected to the comparator 84.
The electromagnetic actuator 68 of the pressure regulating valve 60 is connected between the collectors of the transistors 85 and 86 and the constant voltage source 83.

Therefore, when the temperature setting is, for example, at the maximum cooling position, the suction pressure is, for example, 1.8 kg/
cm ²・G, the evaporation pressure at the evaporator outlet will be 2.0Kg/cm ²・G, and the evaporation temperature will be approximately 0℃ (the pressure loss between the compressor and the evaporator will be 0.2Kg). /cm ² ·G.) In this state, when the heat load decreases, both the discharge pressure and the temperature decrease, and the resistance of the temperature sensor 81 increases, so the input voltage to the comparator 84 increases, causing current control. Circuit 80 causes more current to flow through electromagnetic actuator 68 . As a result, the opening degree of the valve body 62 becomes smaller, so the pressure in the crank chamber 26 becomes higher, the inclination angle of the rocking plate 55 becomes smaller, and the discharge capacity decreases. Therefore, the suction pressure increases to, for example, 2.1Kg/cm ² ·G, and at this time the refrigerant flow rate also decreases, so if the pressure loss between the compressor suction port and the evaporator is 0.1Kg/cm ² ·G. ,
It is operated at an evaporation pressure of 2.0 Kg/cm ² ·G and a temperature of 0°C.

On the other hand, when the thermal load increases and the temperature rises, the resistance of the temperature sensor 81 decreases and the input voltage to the comparator 84 decreases, so the electromagnetic actuator 6
The current flowing through the valve body 8 decreases, and the opening degree of the valve body 62 increases. As a result, the pressure in the crank chamber 26 decreases and the capacity of the compressor increases, so the suction pressure decreases to, for example, 1.7 Kg/cm ² ·G, and at this time the refrigerant flow rate increases, reducing the pressure loss by 0.3 If Kg/cm ² ·G, the evaporation pressure will be 2.0Kg/cm ² ·G and the temperature will be 0°C.

As described above, under the same setting conditions, the opening degree of the solenoid valve is corrected so that the evaporation pressure is always constant regardless of changes in heat load, so a desired cooling state can be maintained.

(Effects of the Invention) As explained above, the present invention has a valve body that opens and closes a communication path between a suction chamber and a crank chamber and has a pressure receiving surface that receives pressure in the suction chamber, and The suction chamber and the Variable displacement type rocker configured to adjust the degree of communication with the crank chamber, change the pressure in the crank chamber, adjust the inclination angle of the rocker plate, and change the piston stroke to vary the discharge volume. The plate compressor is equipped with a correction means that detects a change in thermal load and corrects the magnitude of the current supplied to the electromagnetic actuator in accordance with the change.
If the desired set value of the cooling capacity is constant, even if the heat load or engine speed changes, the opening degree of the valve body will be immediately corrected by the pressure-responsive body according to the change, so the evaporation pressure of the evaporator will be adjusted. It can be kept constant and the desired cooling state can always be obtained.

In addition, the current supplied to the electromagnetic actuator only needs to be controlled according to changes in the thermal load, and at this time, it is sufficient to compensate for the effect of the pressure-responsive body.
The correction means for controlling the current may also be simple. Therefore, the device does not become larger and costs can be reduced.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway plan view of an embodiment of the compressor according to the present invention, Fig. 2 is a longitudinal sectional side view of the same, Fig. 3 is an enlarged longitudinal sectional view of the solenoid valve, and Fig. 4 is an enlarged longitudinal sectional view of the same solenoid valve. FIG. 5 is an enlarged vertical cross-sectional view of the main part of FIG. 5, and is a diagram showing the current control circuit. 21c...Communication port between the suction chamber and the crank chamber, 2
2... Piston, 26... Crank chamber, 41...
Suction chamber, 55... Rocking plate, 62... Valve body, 62a
...Pressure receiving surface, 68...Electromagnetic actuator, 80
...Current control circuit, 81...Temperature sensor.

Claims (1)

[Claims] 1. A valve body that opens and closes a communication path between a suction chamber and a crank chamber and has a pressure receiving surface that receives pressure in the suction chamber, and a pressure responsive body that controls the opening degree of the valve body according to the pressure in the suction chamber. The degree of communication between the suction chamber and the crank chamber is adjusted by a pressure regulating valve having an electromagnetic actuator that controls the degree of opening of the valve body according to the magnitude of the current supplied to the solenoid. In a variable displacement wobble plate compressor configured to adjust the inclination angle of the wobble plate by changing the indoor pressure and change the piston stroke to vary the discharge capacity, a change in thermal load is detected, A variable capacity wobble plate compressor, comprising a correction means for correcting the magnitude of the current supplied to the electromagnetic actuator in accordance with the change.