JPH0344234B2 - - 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, the discharge capacity can be varied by selectively connecting the suction side low pressure chamber and the crank chamber by controlling a pressure regulating valve and arbitrarily changing the pressure in the crank chamber. JP-A No. 52-96407 is known as a variable capacity rocking plate compressor constructed as described above.

According to such conventional compressors, the piston stroke can be controlled using the pressure control valve to keep the suction pressure constant. In order to immediately reduce the discharge capacity to zero and divert the power of the compressor to engine operation, or to prevent the evaporator from freezing, the temperature of the compressor should be reduced to zero.
There is a problem in that it is not possible to perform controls such as stopping the operation of the compressor when the temperature reaches around .degree.

(Object of the Invention) The present invention has been made in view of the above circumstances, and it is possible to increase or decrease the discharge capacity of the compressor by an electrical external signal, and when a rapid reduction in the discharge capacity is required such as acceleration cut etc. The object of the present invention is to provide a variable displacement wobble plate compressor that enables rapid reduction in discharge capacity.

(Means for Solving the Problems) In order to solve the above-mentioned problems, in the present invention, the suction side low pressure chamber and the discharge side high pressure chamber are selectively communicated with the crank chamber by controlling the pressure regulating valve. In the variable capacity wobble plate compressor configured to be able to vary the discharge capacity by arbitrarily changing the crank chamber pressure, the pressure regulating valve is a valve that opens and closes a communication passage between the high pressure chamber and the crank chamber. 1
and a second valve element that opens and closes a communication path between the low pressure chamber and the crank chamber, and the first valve element is operated to open and close by a solenoid and opens when the solenoid is turned off. The second valve body is configured to open and close when the low pressure chamber pressure is turned on, and the second valve body is opened and closed by a pressure responsive member that senses the pressure in the low pressure chamber when the pressure in the low pressure chamber is equal to or higher than a predetermined set value. The first valve body and the second valve body are connected to each other by a biasing member that biases both the valve bodies in the valve closing direction. By doing so, when the solenoid is turned on, a force is not applied to the pressure responsive member in the direction of opening the first valve body, and the current value applied to the solenoid is changed. Accordingly, the low pressure chamber pressure setting value can be varied.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. 1 and 2 show a cross section of a variable displacement rocking plate compressor according to the present invention, and in both figures, 1 is a housing, which includes a cylindrical case 2 and one end surface of the case 2 (the left end surface in the figure). ), a cylinder head 4 is fluid-tightly attached to the case 2 via a valve plate 3, and a head member 5 is fluid-tightly attached to the other end surface (the right end surface in the figure) of the case 2. A cylinder block 6 is integrally formed inside the case 2, and a crank chamber 7 is defined by the end surface of the cylinder block 6 on the side of the head member 5, the inner peripheral wall of the case 2, and the inner surface of the head member 5. ing. An oil reservoir 8 is formed inside the lower part of the case 2, and the oil reservoir 8 communicates with the crank chamber 7. The cylinder block 6 has a plurality of cylinders arranged at predetermined intervals in the circumferential direction, centered on the drive shaft 9 disposed substantially along the central axis of the housing 1, and with the axis parallel to that of the drive shaft 9. Cylinder 10 is provided, and a piston 11 is slidably fitted into each cylinder 10. The drive shaft 9 has its cylinder head 4 side end rotatably supported in the center hole 6a of the cylinder block 6 via a ball bearing 12, and its head member 5 side end supported by an arm member 13 and a large diameter ball. It is rotatably supported on the inner circumferential surface of the head member 5 via bearings 14 in turn. A shaft end of the drive shaft 9 on the head member 5 side passes through the center hole 5a of the head member 5 and extends outward, and a pulley 15 is fitted to the extended end. There is. A mechanical seal 16 is interposed between the boss portion 13a of the arm member 13 and the center hole 5a of the head member 5, and the space between the boss portion 13a and the center hole 5a of the head member 5 is maintained airtight. ing. The pulley 15 is connected to a pulley on the output shaft side of an on-vehicle engine (not shown) by a drive belt (not shown), and the rotation of the engine is caused by the drive shaft 9.
transmitted to. A sleeve-shaped slider 17 that slides back and forth on the drive shaft 9 is fitted on the drive shaft 9, and a trunnion pin 18 perpendicular to the drive shaft 9 is implanted on the outer periphery of the slider 17. Reference numeral 19 denotes a disc-shaped rocking plate, and the rocking plate 19 has a center hole 19.
a is loosely fitted around the outer periphery of the slider 17, and the trunnion pin 18 is fitted into a hole (not shown) drilled in the inner peripheral surface of the center hole 19a, so that the swing plate 1
9 and the slider 17 engage with each other, so that the rocking plate 1
The center portion of the slider 9 moves on the drive shaft 9 together with the slider 17, and can tilt in the axial direction about the trunnion pin 18 with respect to the drive shaft 9. In the illustrated example, one side of the rocking plate 19 is formed of a separate plate member 19b having high wear resistance, and this plate member 19b is attached to the main body of the rocking plate 19 in a freely sliding manner. There is.

Further, a pivot pin 20 is attached to this swing plate 19 via a bracket 21, which is located on the side opposite to the cylinder block and is located near a point on the extension line of the axis of a specific piston 11' in the cylinder 10. It is being The pivot pin 20 is
It is engaged with a guide hole 22 provided in the arm member 13, and the rotation of the drive shaft 9 is transmitted to the swing plate 19, and the swing plate 19 is connected to the trunnion pin 1.
8 and pivot pin 20 as movement fulcrums. A recess 1 bored in the inner end surface of the arm member 13
3b is provided with a coil spring 23 as an elastic means, and the spring 23 constantly presses the slider 17 to the left in FIG.
9 is constantly biased in the direction of decreasing the inclination angle. on the other hand,
A stopper 25 of the slider 17 is fitted and fixed to the end of the drive shaft 9 on the cylinder block 6 side, and the stopper 25 of the slider 17 is fitted and fixed to the end of the drive shaft 9 on the cylinder block 6 side. The minimum inclination angle of the moving plate 19 is regulated. When the rocking plate 19 is at the minimum inclination angle position regulated by the stopper 25, the piston 11 is set to make a stroke movement over several percent of its maximum stroke length.

Further, when the swing plate 19 is at the minimum inclination angle position, the swing plate 19 is perpendicular to the drive shaft 9 so that the suction stroke of each piston 11 starts from the upper limit position, which is the top dead center of the cylinder 10. The pivot pin 20 is pivotally connected to the pivot pin 20 spaced apart in the direction.

The tips of piston rods 26 projecting from the piston 11 are connected to the cylinder block 6 side surface of the swing plate 19 via ball joints 27, respectively. Therefore, as the swing plate 19 rotates, the piston 11 swings. Also,
The angle of inclination of the swing plate 19 relative to the vertical plane changes depending on the pressure within the crank chamber 7, and the stroke of the piston 11 increases or decreases due to the change in the angle of inclination.

The valve plate 3 is provided with a pair of suction valves (not shown) and a discharge valve 28, and each suction valve is connected to the valve plate 3 and the cylinder head 4.
Each discharge valve 28 communicates with a suction chamber (low pressure chamber) 29 defined between the two and a discharge chamber (high pressure chamber) 30, respectively. The discharge chamber 30 has a check valve 3 that opens when the pressure within the discharge chamber 30 exceeds a predetermined set value.
1 to the refrigerant circuit of the air conditioner (not shown)
The discharge port 32 is connected to the discharge port 32 .

A pressure regulating valve 33 is provided in the center of the cylinder head 4. The pressure regulating valve 33 is the third
It is configured as shown in the figure. That is, the pressure regulating valve 33 has a valve housing 34 and first and second valve bodies 35 and 36 provided within the valve housing 34. The valve housing 34 is formed by screwing a small-diameter second member 34b onto the tip of a large-diameter first member 34a, and has a fitting hole 4a in the center of the cylinder head 4.
The distal end surface of the second member 34b is in close contact with the valve plate 3. Said valve housing 3
A plurality of O rings 37 maintain an airtight state between the outer circumferential surface of the fitting hole 4 and the inner circumferential surface of the fitting hole 4a.

A valve body fitting hole 38 is provided inside the axis of the first member 34a of the valve housing 34. The valve body fitting hole 38 is located on one end side (the second member 34
b side) has a larger diameter than the other end side (the side opposite to the second member 34b), and the inner circumferential surface of the large diameter portion 38a is perforated along the radial direction and at a predetermined interval from each other in the axial direction. The inner end surfaces of the provided first passage 39 and second passage 40 are open. The outer end surface of the first passage 39 on the second member 34b side is connected to the crank chamber 7 through a third passage 41 provided inside the cylinder head 4.
It communicates with the inside. Further, the outer end surface of the second passage 40 on the side opposite to the second member 34b is connected to the discharge chamber 3 through a fourth passage 42 provided inside the cylinder head 4.
Connected to 0.

The first valve body 35 is provided in the valve body fitting hole 38 of the first member 34a. The first valve body 35 has a valve shaft 35b protruding from the center of one end surface of a circular disk-shaped valve body 35a, and a communication hole 35c is formed in the valve body 35a. The valve body 35a is located in the large diameter portion 38a of the valve body fitting hole 38, and the valve shaft 35b is located in the valve body fitting hole 38.
They are slidably fitted into the small diameter portions 38b of No. 8, respectively. The first valve body 35 opens and closes the inner end surface opening of the second passage 40 by sliding in the axial direction of the first valve body 35a. The first to fourth communication passages 39 to 42 and the communication hole 3 of the first valve body 35
5c constitutes a communication passage 43 that communicates the discharge chamber 30 and the crank chamber 7, and the communication passage 43 is opened and closed by the first valve body 35.

The valve shaft 35b of the first valve body 35 is a plunger and closes when the solenoid 44 is turned on.
The valve opens when it is turned off. The solenoid 44 is attached to the center of the outer end surface of the first member 34a of the valve housing 34, is connected to a control unit (not shown) via a lead wire 45, and is turned on and off by an output signal from the control unit. controlled. Further, the value of the current supplied to the solenoid 44 can be varied, and by setting the value of the current supplied, the pressure value in the suction chamber 29 can be varied.

A valve body fitting hole 46 is provided inside the axis of the second member 34b of the valve housing 34. A partition wall 47 is interposed within the valve body fitting hole 46 at the boundary between the first member 34a and the second member 34b. The partition wall 47 has a protrusion 48 at the center of one end surface (end surface on the side of the valve plate 3) and a spring fitting hole 49 inside the shaft center. Said second member 34
The inner end surface of a fifth passage 50 bored along the radial direction opens on the inner circumferential surface of the valve body fitting hole 46 of b, and the outer end surface of the fifth passage 50 is located inside the cylinder head 4. The suction chamber 29 via the sixth passage 51 provided
It communicates with the inside. Further, a seventh passage 52 is bored in the center of the inner end surface of the valve body fitting hole 46 of the second member 34b, and the seventh passage 52 is connected to the eighth passage 53 bored in the valve plate 3 and the seventh passage 52. It communicates with the crank chamber 7 via a ninth passage (not shown) provided in the cylinder block 6. Said fifth
By the eighth passages 50 to 53 and the ninth passage,
A communication passage 54 is configured to communicate the suction chamber 29 and the crank chamber 7, and the communication passage 54 is opened and closed by the second valve body 36.

The second valve body 36 has circular disc-shaped valve bodies 36b and 36c provided at both ends of a valve shaft 36a. The eighth passage 53 of the valve plate 3 is opened and closed by the first valve body 36b coming into contact with and separating from the valve plate 3. The area of the second valve body 36c on the small diameter side is:
The opening area is set equal to the opening area of the eighth passage 53 of the valve plate 3, so that the second valve body 36 can be smoothly opened and closed along the axial direction by the action of pressure, which will be described later.

This second valve body 36 is attached to a pressure-responsive member 55 that senses the pressure within the suction chamber 29, and is opened and closed by the pressure-responsive member 55.
The valve opens when the pressure in the suction chamber 29 is above a predetermined set value, and closes when the pressure within the suction chamber 29 is below a predetermined set value. The pressure-responsive member 55 sets the pressure in the suction chamber 29 by its setting force, and is composed of hollow bellows 55a and 55b with a double structure. The inner bellows 55a is fixed to each end and is loosely fitted around the outer periphery of the protrusion 48. and,
The first valve body 36b is closely fixed to the outer surface of the other end of the outer bellows 55b, and the valve shaft 36a is located in a space between the other end surface of the inner bellows 55a and the other end surface of the outer bellows 55b, Second
The valve body 36c is closely fixed to the other end surface of the inner bellows 55a. The second valve body 36 is biased in the valve closing direction (rightward in FIG. 3) by a coil spring 56 via the inner and outer bellows 55a, 55b. The spring 56 is fitted within the space between the inner and outer bellows 55a and 55b.

The first valve body 35 and the second valve body 36 are connected to each other by a coil spring 57. The coil spring 57 is loosely fitted into the spring fitting hole 49 of the partition wall 47, and has one end located at the center of the end surface of the valve body 35a of the first valve body 35 and the other end located at the center of the end surface of the valve body 35a of the first valve body 35. are connected and fixed to the center of the end face of the second valve body 36c, respectively. The coil spring 57 is a tension spring, and is connected to the first and second valve bodies 35 and 36.
Both are biased in the valve opening direction. By connecting the first and second valve bodies 35 and 36 with the coil spring 57, the closing direction of the first valve body 35 (in FIG. The movement stroke in the left direction) changes, and accordingly, a force acts on the pressure responsive member 55 in the direction in which the second valve body 36 opens, thereby causing the pressure responsive member 55 to set. The force can be varied to vary the pressure setting within the suction chamber 29.

Note that an air vent groove 58 is formed on the outer surface of the valve shaft 35b of the first valve body 35 over the entire axial length of the valve shaft 35b.
is provided. An oil pump 59 is connected to the end of the drive shaft 9 on the valve plate 3 side, and the oil pump 59 is driven as the drive shaft 9 rotates, supplying lubricating oil from the oil reservoir 8 to the oil pipe 60. The oil is sucked up through an oil passage 61 provided in the cylinder block 6, an oil hole 62 provided in the valve plate 3, and an oil passage 63 provided between the cylinder head 4 and the bell plate 3. It is now possible to supply to the department.

(Function) Next, the function of the variable capacity rocking plate compressor of the present invention having the above structure will be explained.

First, when the operation switch of the air conditioner is turned off and the compressor is stopped or rotating at idle, the slider 17 is moved to the stopper 25 by the spring force of the coil spring 23 because the control unit (not shown) is in an inactive state. Move to the contact position,
The minimum inclination angle is given to the rocking plate 19. Further, the solenoid 44 of the pressure regulating valve 33 is in an OFF state (demagnetized state), and the first valve body 35 is in an open state as shown in FIG. A communication path 43 that communicates with the two is open. Furthermore, since the suction chamber pressure of the second valve body 36 is higher than the set value, the passage 54 communicating between the suction chamber 29 and the crank chamber 7 is open. In this state, the check valve 31 of the discharge chamber 30 is closed by the setting force of its spring, and if the compressor is being rotated at idle at this time, the rocking plate 19 is moved to the maximum stroke length of the piston 11 as described above. The refrigerant gas sucked in and discharged by the piston 11 is formed by the cylinder bore, the suction chamber 29, the discharge chamber 30, the crank chamber 7, and a passage bypassing these. Circulation takes place at a small rate in a closed circuit.

Next, when the operation switch of the air conditioner is turned on, the control unit operates and supplies the solenoid 44 of the pressure regulating valve 33 with a control signal corresponding to an input signal representative of the parameters described later. When a current of, for example, 200 mA is applied, the first valve body 35 is moved to the valve closing position shown in FIG. By closing, the communication passage 43 that communicates the discharge chamber 30 and the crank chamber 7 is closed. Further, as the first valve body 35 closes, the pressure responsive member 54 is reduced by a predetermined size via the spring 57 against the spring force of the spring 55, so that the second valve body 36 is reduced in size by a predetermined size. The first valve body 36b urges the seventh passage 52 in the direction of opening. If the compressor is rotating in such a state, the rocking plate 19 is given the minimum inclination angle as described above, and the piston 11 is aligned with the cylinder 1.
The refrigerant gas is sucked into the cylinder 10 from the suction chamber 29 via the suction valve, and the refrigerant gas is sucked into the cylinder 10 through the suction valve 28.
is discharged into the discharge chamber 30 through the suction chamber 29 and the discharge chamber 30 to generate suction negative pressure and discharge pressure, respectively, and when the discharge pressure exceeds the spring force of the check valve 31 of the discharge chamber 30, the check valve 31 When the valve 31 is opened, compressed refrigerant is supplied from the discharge port 32 to the refrigerant circuit, and the pressure inside the crank chamber 7 is increased from the eighth passage 53 to the seventh passage 5.
2→valve body fitting hole 46→sixth passage 51 (communication passage 54) and escapes into the suction chamber 29, so the pressure in the crank chamber 7 decreases. Therefore, the rocking plate 1
9 increases the inclination angle and increases the stroke length of the piston 11 as the differential pressure between the reaction force of the compression action of the piston 11 and the internal pressure of the crank chamber 7, which acts as back pressure of the piston 11, increases. Increase the discharge amount. In this way, when the pressure inside the suction chamber 29 becomes lower than the predetermined value due to the increase in the discharge amount, the second member 34b communicates with the inside of the suction chamber 29 via the fifth passage 50 and the sixth passage 51. The pressure-responsive member 55 in the valve body insertion hole 46 expands, and as a result, the first valve body 36b of the second valve body 36 closes the seventh passage 52, thereby opening the suction chamber 29 and the crank chamber. 7 is closed. With the blockage of the communication passage 54, the crank chamber 7
Since the internal pressure does not escape to the suction chamber 29 side, the pressure in the crank chamber 7 increases due to the high pressure and blow-by gas pressure introduced into the crank chamber 7 from the discharge chamber 30. Therefore, the rocking plate 19 decreases its inclination angle as the differential pressure between the reaction force of the compression action of the piston 11 and the internal pressure of the crank chamber 7, which acts as back pressure of the piston 11, decreases, thereby increasing the stroke length of the piston 11. decreases and reduces the discharge amount. In this way, when the pressure in the suction chamber 29 becomes equal to or higher than a predetermined value due to a decrease in the discharge amount, the pressure responsive member 55 is contracted against the spring 56 due to the pressure, and the second valve body is 36 opens the seventh passage 52, thereby opening the communication passage 54 that communicates the suction chamber 29 and the crank chamber 7, and the pressure in the crank chamber 7 escapes into the suction chamber 29 through the communication passage 54. Therefore, the pressure inside the crank chamber 7 decreases. Therefore, the stroke length of the piston 11 is increased again in the same manner as described above to increase the discharge capacity.

In this way, if the discharge capacity of the compressor decreases below or exceeds the discharge capacity required for the heat load of the air conditioner, or if the heat load of the air conditioner increases or decreases, the discharge rate of the compressor increases to meet the heat load. When the discharge volume falls below or exceeds the required discharge volume, the above operation is repeated each time to automatically control the discharge volume to an optimum state and maintain the pressure in the suction chamber 29 at a predetermined set value.

When the current value supplied to the solenoid 44 of the pressure regulating valve 33 is set to, for example, 1A in the above-described control operation for the discharge capacity of the compressor, the first valve body 35 resists the spring force of the spring 57 and enters the state shown in FIG. 6, the pressure response member 55 sets the pressure in the suction chamber 29 lower than in the case shown in FIG. 5.

Furthermore, when the engine is suddenly accelerated while the compressor is in an operating state where the discharge capacity is large, the solenoid 44 of the pressure regulating valve 33 is turned off, and the first valve body 35 is moved by the spring force of the spring 57. When it is moved to the right side, the inner end surface of the fourth passage 42 is opened, as shown in FIG. 4, and the valve is in an open state. Therefore, the high pressure gas in the discharge chamber 30 passes through the fourth passage 42 → second passage 40 → communication hole 35c of the first valve body 35 → first passage 39 → third passage 41 (communication passage 43). Tsute crank chamber 7
flow inward. On the other hand, since the biasing force of the spring 57 is eliminated, the second valve body 36 is moved together with the pressure responsive member 55 in the valve closing direction, and the communication path 54 between the suction chamber 29 and the crank chamber 7 is closed, so that the crank The pressure in the chamber 7 rises rapidly, and the inclination angle of the rocking plate 19 decreases accordingly, reducing the discharge capacity, resulting in so-called acceleration cut control that allows the power of the compressor to be directed to engine running. is to be done.

(Effects of the Invention) As detailed above, the variable displacement rocking plate compressor of the present invention selectively communicates the suction side low pressure chamber and the discharge side high pressure chamber with the crank chamber by controlling the pressure regulating valve. In the variable capacity wobble plate compressor configured to be able to vary the discharge capacity by arbitrarily changing the crank chamber pressure, the pressure regulating valve is a valve that opens and closes a communication passage between the high pressure chamber and the crank chamber. the first valve body, and a second valve body that opens and closes a communication path between the low pressure chamber and the crank chamber;
The second valve element is configured to be opened and closed by a solenoid so that it opens when the solenoid is turned off and closes when the solenoid is turned on, and the second valve element is configured to operate at a pressure that senses the low pressure indoor pressure. The first valve body and the second valve body are configured to be opened and closed by a responsive member so that the valve opens when the pressure in the low pressure chamber is above a predetermined set value and closes when the pressure within the low pressure chamber is below a predetermined set value. By connecting these two valve bodies to each other with a biasing member that biases them in the valve closing direction, when the solenoid is turned on, the second valve body is directed toward the valve opening direction relative to the pressure responsive member. The present invention is characterized in that the low pressure chamber pressure setting value can be varied by changing the current value applied to the solenoid.

Therefore, the discharge capacity of the compressor can be increased or decreased by an electrical external signal, and when an acceleration cut is required, the discharge capacity can be rapidly reduced, and various controls can be performed as necessary.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a partially cutaway side view of the compressor of the present invention, FIG. 2 is a cross-sectional view of the compressor, FIG. 4
The figure is a cross-sectional view of the first valve body in the open state, Figure 5 is a cross-sectional view of the first valve body in the closed state when the current value is a prescribed value, and Figure 6 is a cross-sectional view of the first valve body when the current value is the maximum value. FIG. 3 is a sectional view of the first valve body in a closed state in the case of FIG. 7... Crank chamber, 19... Rocking plate, 29...
Suction chamber (low pressure chamber), 30...Discharge chamber (high pressure chamber), 3
3... Pressure regulating valve, 35... First valve body, 36...
... second valve body, 43 ... communication path between the high pressure chamber and the crank chamber, 44 ... solenoid, 54 ... communication path between the low pressure chamber and the crank chamber, 55 ... pressure responsive member,
57... Spring (biasing member).

Claims (1)

[Claims] 1. A variable capacity variable capacity configured so that the discharge capacity can be varied by selectively communicating the suction side low pressure chamber and the discharge side high pressure chamber with the crank chamber under the control of a pressure regulating valve and arbitrarily changing the pressure within the crank chamber. In the type rocking plate compressor, the pressure regulating valve is a first valve that opens and closes a communication path between the high pressure chamber and the crank chamber.
and a second valve element that opens and closes a communication path between the low pressure chamber and the crank chamber, and the first valve element is operated to open and close by a solenoid and opens when the solenoid is turned off. The second valve body is configured to open and close when the low pressure chamber pressure is turned on, and the second valve body is opened and closed by a pressure responsive member that senses the pressure in the low pressure chamber when the pressure in the low pressure chamber is equal to or higher than a predetermined set value. The first valve body and the second valve body are connected to each other by a biasing member that biases both the valve bodies in the valve closing direction. By doing so, when the solenoid is turned on, a force is not applied to the pressure responsive member in the direction in which the second valve body opens the valve, and furthermore, the value of the current flowing to the solenoid is changed. A variable capacity wobble plate compressor, characterized in that the low pressure chamber pressure setting value can be varied.