JP2003343433A - Control valve for variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control valve capable of conducting feedback control to compression delivery quantity in simple constitution. <P>SOLUTION: A restrictor passage 59 is formed of an inner circumferential surface of a control valve containing part 29 formed in a rear housing 4 of a compressor and an outer circumferential surface of a valve part housing 45b of a valve housing 45 of the control valve CV contained in the control valve containing part 29. PdH is introduced to a first pressure chamber 55 in a pressure sensitive chamber 48, and PdL to a second pressure chamber 56 as pressure-reduced in the restrictor passage 59. Differential pressure Δd is mechanically detected, and in the pressure sensitive member 54 comprising a bellows valve, an actuation rod 40 is positioned in such a way that delivery capacity of the variable displacement compressor is changed to offset fluctuation of the differential pressure Δd, thereby the delivery capacity is feedback- controlled. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control valve for controlling the discharge capacity of a variable displacement compressor used in, for example, a vehicle air conditioner.

[0002]

2. Description of the Related Art As this type of control valve, there is, for example, one disclosed in Japanese Unexamined Patent Publication No. 2001-133053 (hereinafter, Prior Art 1). As a general tendency, the larger the discharge capacity of the compressor and the larger the flow rate of the refrigerant flowing through the refrigerant circulation circuit, the larger the pressure loss per unit length of the circuit or the pipe. That is, the pressure loss between two pressure monitoring points set along the refrigerant circulation circuit, that is, the differential pressure has a positive correlation with the flow rate of the refrigerant in the circuit. Utilizing this tendency,
The control valve of the air conditioner disclosed in this publication grasps the differential pressure between two pressure monitoring points and indirectly detects the discharge capacity of the compressor. A pressure monitoring point is defined, and a downstream (low pressure side) pressure monitoring point is defined in the middle of the flow pipe separated from the pressure monitoring point by a predetermined distance. The control valve mechanically detects the differential pressure between the two points, and directly uses the detected differential pressure to adjust the valve opening degree of itself to perform feedback control of the compressor discharge capacity. In addition, Japanese Patent Laid-Open No. 2001-2001
In another example of the invention described in Japanese Patent Laid-Open No. 107854 (Prior Art 2), there is also disclosed a technique in which a differential pressure is clarified by providing a throttle passage between pressure monitoring points and the distance between the pressure monitoring points is shortened.

[0003]

However, in the above-mentioned technical technique 1, in order to clarify the differential pressure between the two pressure monitoring points, the downstream monitoring point should be separated from the upstream monitoring point to some extent. It is necessary to increase the size of the pressure measuring device,
This led to an increase in costs. Even with the conventional technique 2,
In order for the control valve to detect the differential pressure between the two points, a dedicated pressure detection passage is still necessary, which creates a new problem of increasing the complexity of the air-conditioning system, and is a perfect solution to the problem of increased cost. It wasn't resolved.

An object of the present invention is to provide a control valve capable of feedback controlling the compression discharge capacity with a simple structure.

[0005]

In order to achieve the above object, in the invention of claim 1, the refrigerant circulation circuit of the air conditioner is constituted, and the discharge capacity is based on the pressure of the control pressure chamber formed inside the housing. In a control valve used for a variable capacity compressor capable of changing the variable capacity compressor, a valve housing housed in a control valve housing part of a housing of the variable capacity compressor and forming an outer shell of the control valve; An air supply passage connecting the control pressure chamber and the discharge pressure region of the refrigerant circulation circuit,
Alternatively, a valve chamber partitioned within the valve housing to form a part of the extraction passage that connects the control pressure chamber and the suction pressure region of the refrigerant circulation circuit, and the valve chamber is displaceably accommodated in the valve chamber, A valve body capable of adjusting the opening degree of the air supply passage or the extraction passage according to the position of, a pressure sensing chamber formed in the valve housing, and a valve body operatively connected to the pressure sensing chamber for high pressure. A pressure sensitive member that divides into a low pressure region that communicates with the discharge pressure region or the suction pressure region via a throttle passage, and senses based on fluctuations in the pressure difference between the high pressure region and the low pressure region. The displacement of the pressure member is reflected in the positioning of the valve body and changes the discharge capacity of the variable displacement compressor. Therefore, the valve body moves to the side that cancels the fluctuation of the pressure difference, and The throttle passage that constitutes the section is a valve housing of the pressure-sensitive chamber. It is characterized by being constituted by a valve housing accommodating the inner peripheral surface of the outer peripheral surface and the pressure sensitive chamber portion ring.

Therefore, since the outer peripheral surface of the valve housing of the pressure sensitive chamber portion and the inner peripheral surface of the valve housing accommodating portion of the pressure sensitive chamber portion form a throttle passage, the pressure sensitive chamber and both pressure regions can be brought close to each other, There is no need to provide a complicated dedicated passage for pressure detection that connects the pressure monitoring point and each pressure chamber as in the prior art. Therefore, it is possible to reduce the size of the pressure sensitive member and simplify the configuration of the control valve, which leads to cost reduction.

According to a second aspect of the present invention, in the first aspect, the throttle passage is formed by a gap between the inner peripheral surface of the control valve accommodating portion and the outer peripheral surface of the valve housing in the pressure sensing chamber portion. Therefore, it is not necessary to specially process the compressor housing and the valve housing to form the throttle passage.
Further, in general, the inner peripheral surface of the control valve accommodating portion is formed with very high dimensional accuracy and a smooth surface (low surface roughness) in order to maintain the airtightness of the compressor. It also has the excellent effect of becoming better.

According to a third aspect of the present invention, in the first aspect, the throttle passage has a gap between the outer peripheral surface of the valve housing in the pressure sensitive chamber portion and the inner peripheral surface of the casing arranged on the outer periphery of the valve housing in the pressure sensitive chamber portion. It is formed in. With this configuration, the width of the throttle passage, that is, the throttle amount can be freely changed by changing the thickness of the casing.

The invention of claim 4 is based on claims 1 to 3,
The control valve accommodating portion is formed such that the space formed by the valve housing accommodating portion of the pressure sensing chamber portion and the end surface of the control valve is also in the high pressure region or the low pressure region. If formed in this way,
It is possible to separate the passage for introducing the refrigerant into the high pressure region or the low pressure region in the pressure sensing chamber from the throttle passage, and it is not necessary to provide the throttle passage for the refrigerant in the pressure sensing member itself, and the pressure sensing member can be simplified. Moreover, both pressure regions do not need to be part of the refrigerant circulation circuit. Therefore, the range of application of the pressure-sensitive member can be expanded, for example, it can be applied to a bellows valve and a diaphragm valve.

The invention of claim 5 is based on claims 1 to 4,
A communication passage is formed in the valve housing to connect the high pressure region or the low pressure region with the supply passage or the extraction passage formed in the valve chamber. Therefore, it is not necessary to form either the air supply passage or the extraction passage in the compressor housing, and the structure of the compressor housing can be simplified.

The invention of claim 6 is based on claims 1 to 5,
At least a part of the end surface of the control valve is provided with a filter for preventing foreign matter from entering the pressure sensing chamber and / or the communication passage, or both. According to this structure, it is possible to prevent a decrease in the responsiveness of the capacitance change due to the entry of foreign matter.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION First to third embodiments in which the present invention is embodied in a control valve of a variable displacement swash plate compressor used in a vehicle air conditioner will be described below. In the second and third embodiments, only differences from the first embodiment will be described, and the same or corresponding members will be denoted by the same reference numerals and description thereof will be omitted.

First Embodiment (Variable Capacity Swash Plate Compressor) As shown in FIG. 1, a crank chamber 5 as a control pressure chamber is provided in a region surrounded by the cylinder block 1 and the front housing 2. It is partitioned. A drive shaft 6 is rotatably supported in the crank chamber 5. A lug plate 11 is integrally rotatably fixed on the drive shaft 6 in the crank chamber 5.

The front end of the drive shaft 6 is a vehicle engine E as an external drive source via a power transmission mechanism (not shown).
Is operatively connected to. The power transmission mechanism may be a clutch mechanism (for example, an electromagnetic clutch) capable of selecting transmission / interruption of power by electric control from the outside, or a clutchless mechanism of a constant transmission type without such a clutch mechanism. (Eg belt / pulley combination). In this embodiment, a clutchless type power transmission mechanism is adopted.

A swash plate 12 as a cam plate is housed in the crank chamber 5. The hinge mechanism 13 is interposed between the lug plate 11 and the swash plate 12. The swash plate 12 can rotate synchronously with the lug plate 11 and the drive shaft 6 by the hinge connection with the lug plate 11 via the hinge mechanism 13 and the support of the drive shaft 6.

A plurality of cylinder bores 1a (only one is shown in the drawing) are provided with a drive shaft 6 in the cylinder block 1.
Is formed so as to surround. The single-headed piston 20 is reciprocally housed in each cylinder bore 1a. The front and rear openings of the cylinder bore 1a are closed by the valve / port forming body 3 and the piston 20, and a compression chamber whose volume changes according to the reciprocating movement of the piston 20 is defined in the cylinder bore 1a. Each piston 20
Are anchored to the outer peripheral portion of the swash plate 12 via shoes 19. Therefore, the rotational movement of the swash plate 12 associated with the rotation of the drive shaft 6 is converted into the reciprocating linear movement of the piston 20 via the shoe 19.

In the space formed by the valve / port forming body 3 and the rear housing 4, the suction chamber 2 located in the central region is located.
1 and a discharge chamber 22 surrounding it are defined. In the valve / port formation body 3, a suction port 23, a suction valve 24 for opening / closing the port 23, and a discharge port 25 and a discharge valve 26 for opening / closing the port 25 are formed corresponding to the vertical movement of each cylinder bore 1a. Has been done. The suction chamber 21 and the cylinder bores 1a communicate with each other through the suction port 23, and the cylinder bores 1a and the discharge chamber 22 communicate with each other through the discharge port 25.

Then, the refrigerant gas in the suction chamber 21 moves forward from the top dead center position of each piston 20 to the bottom dead center side, and passes through the suction port 23 and the suction valve 24 to the cylinder bore 1.
Inhaled by a. The refrigerant gas sucked into the cylinder bore 1a is compressed to a predetermined pressure by returning from the bottom dead center position of the piston 20 to the top dead center side, and is discharged to the discharge chamber 22 via the discharge port 25 and the discharge valve 26. To be done.

The inclination angle of the swash plate 12 (the angle formed between the swash plate 12 and a plane orthogonal to the axis of the drive shaft 6) is the moment of the rotational movement due to the centrifugal force during the rotation of the swash plate 12, and the piston 20. It is determined based on the mutual balance of various moments such as moment due to reciprocating inertia force and moment due to gas pressure. The moment due to the gas pressure is a moment generated based on the mutual relationship between the internal pressure of the cylinder bore 1a and the internal pressure of the crank chamber 5 (crank pressure Pc) as the control pressure corresponding to the back pressure of the piston 20. Accordingly, it acts both in the direction of decreasing the tilt angle and in the direction of increasing the tilt angle.

In this compressor, the inclination angle of the swash plate 12 is set to the minimum inclination angle (indicated by the solid line in FIG. 1) by adjusting the crank pressure Pc by using a pressure control mechanism described later and appropriately changing the moment due to the gas pressure. It is possible to set any angle between the state shown) and the maximum inclination angle (state shown by the chain double-dashed line in FIG. 1).

(Crank chamber pressure control mechanism) The swash plate 1
The crank pressure control mechanism for controlling the crank pressure Pc involved in the inclination angle control of No. 2 includes a bleed passage 27, an air supply passage 28, and a control valve accommodating portion 29 provided in the compressor housing shown in FIG. The control valve CV accommodated in the. The bleed passage 27 connects the suction chamber 21 which is the suction pressure (Ps) region and the crank chamber 5. The supply passage 28 communicates the discharge chamber 22 which is the discharge pressure (Pd) region with the crank chamber 5, and a control valve CV is arranged in the middle thereof.

Then, by adjusting the opening of the control valve CV, the introduction amount of the discharge gas into the crank chamber 5 through the air supply passage 28 is controlled, and the amount of the discharged gas from the crank chamber 5 through the bleed passage 27 is controlled. Crank pressure Pc from the balance with the amount of gas discharged
Is determined. According to the change of the crank pressure Pc, the difference between the crank pressure Pc via the piston 20 and the internal pressure of the cylinder bore 1a is changed, and the inclination angle of the swash plate 12 is changed. Adjusted.

(Refrigerant Circulation Circuit) The refrigerant circulation circuit (refrigeration cycle) of the vehicle air conditioner is composed of the above-mentioned compressor and the external refrigerant circuit 30. The external refrigerant circuit 30 includes, for example, a condenser 31 and a thermal expansion valve 32 as a pressure reducing device.
And an evaporator 33. The opening degree of the expansion valve 32 is feedback-controlled based on the temperature detected by the temperature sensitive tube 34 provided on the outlet side or the downstream side of the evaporator 33 and the evaporation pressure (the outlet pressure of the evaporator 33). The expansion valve 32 supplies the liquid refrigerant suitable for the heat load to the evaporator 33 to adjust the refrigerant flow rate in the external refrigerant circuit 30.

In the downstream region of the external refrigerant circuit 30, a refrigerant flow pipe 35 is provided which connects the outlet of the evaporator 33 and the suction port 37 provided in the rear housing 4 of the compressor. In the upstream region of the external refrigerant circuit 30, a refrigerant flow pipe 36 that connects the discharge port 38 provided in the rear housing 4 of the compressor and the inlet of the condenser 31 is provided. The compressor sucks and compresses the refrigerant gas introduced into the suction chamber 21 from the downstream region of the external refrigerant circuit 30 through the suction port 37, and discharges the compressed gas to the discharge chamber 22. The refrigerant gas discharged into the discharge chamber 22 is discharged from the discharge passage 39, which also serves as the air supply passage, to the upstream region of the external refrigerant circuit 30 via the discharge port 38 formed in the control valve housing portion 29. In this embodiment, the upstream side is the discharge pressure area side, and the downstream side is the suction pressure area side.

Now, as the flow rate of the refrigerant flowing through the circulating refrigerant circuit in the previous period increases, the pressure loss per unit length of the circuit or piping also increases. That is, the pressure loss (differential pressure) between the two pressure monitoring points P1 and P2 set along the refrigerant circulation circuit has a positive correlation with the refrigerant flow rate in the circuit. Therefore, grasping the differential pressure between the two pressure monitoring points P1 and P2 (hereinafter referred to as the two-point differential pressure ΔPd) is nothing but indirectly detecting the refrigerant flow rate in the refrigerant circulation circuit.

(Control valve) As shown in FIG. 2, the control valve CV
Is provided with an inlet side valve portion (upper side in the drawing) which is a differential pressure detecting means and a valve opening adjusting means, and a solenoid portion 60 (lower side in the drawing) which constitutes an external control means for externally controlling the valve opening degree. The inlet side valve portion adjusts the opening degree (throttle amount) of the air supply passage 28 that connects the discharge chamber 22 and the crank chamber 5. The solenoid portion 60 includes the operating rod 4 arranged in the control valve CV.
It is a kind of electromagnetic actuator for controlling the bias of 0 based on energization control from the outside. The operating rod 40 is
Shut-off portion 41 that is a tip portion, connecting portion 42, valve body portion 4 at substantially the center
3 and a guide rod portion 44 that is a base end portion. The valve body portion 43 corresponds to a part of the guide rod portion 44.

The valve housing 45 of the control valve CV
Is composed of a plug body 45a, a valve portion housing 45b which constitutes the main outer shell of the inlet side valve portion, and a solenoid portion housing 45c which constitutes the main outer shell of the solenoid portion 60. Valve housing 45b of valve housing 45
A valve chamber 46 and a valve hole 47 are defined therein, and a pressure sensitive chamber 48 is defined between the valve portion housing 45b and a plug body 45a press-fitted in the upper portion thereof. Further, the filter 45e is provided on the end surface 45d on the inner side of the control valve housing portion 29 of the control valve CV including the valve housing 45 and the plug body 45a.
Is provided.

An operating rod 40 is disposed in the valve chamber 46 and the valve hole 47 so as to be movable in the axial direction (vertical direction in the drawing). The valve chamber 46 and the valve hole 47 are the operating rod 40.
Depending on the position, communication will be possible. On the other hand, the valve hole 47 and the pressure sensing chamber 48 are the same as the operating rod 4 fitted in the valve hole 47.
It is blocked by the blocking unit 41 of 0.

The bottom wall of the valve chamber 46 is provided by the upper end surface of the fixed iron core 62 described later. A radially extending port 51 is provided on the peripheral wall of the valve housing 45 surrounding the valve chamber 46, and the port 51 connects the valve chamber 46 to the discharge chamber 22 via the upstream portion of the air supply passage 28. Valve hole 4
A port 52 extending in the radial direction is also provided on the peripheral wall of the valve housing 45 surrounding the valve 7, and the port 52 connects the valve hole 47 to the crank chamber 5. Therefore, port 5
1, the valve chamber 46, the valve hole 47, and the port 52 constitute a part of the air supply passage 28 that connects the discharge chamber 22 and the crank chamber 5 as a control valve passage.

The valve body portion 43 of the operating rod 40 is arranged in the valve chamber 46. The step located at the boundary between the valve chamber 46 and the valve hole 47 forms a valve seat 53. Then, the operating rod 40 moves from the position (lowermost moving position) of FIG.
Is moved to the uppermost position where the valve seat 53 is seated, the valve hole 47 is closed. That is, the valve body portion 43 of the actuating rod 40 functions as a valve body on the inlet side in which the opening degree of the air supply passage 28 can be arbitrarily adjusted.

A pressure sensitive member 54 made of a bellows is housed in the pressure sensitive chamber 48. The pressure-sensitive member 54 is made of a metal material such as copper, and its upper end is fixed to the plug body 45a of the valve housing 45 by welding or the like. Therefore, the inside of the pressure-sensitive chamber 48 has a bottomed cylindrical pressure-sensitive member 54.
The first pressure chamber 5 which is the inner space of the pressure sensitive member 54.
5 and a second pressure chamber 56 which is an outer space of the pressure sensitive member 54.

A rod receiver 54a is provided in the bottom wall portion of the pressure-sensitive member 54, and the tip of the blocking portion 41 of the operating rod 40 is inserted into the rod receiver 54a. The pressure-sensitive member 54 is assembled in a state of being compressed and elastically deformed, and is pressed against the blocking portion 41 via the rod receiver 54a by an urging force based on this elastic deformation. The initial elastic deformation amount of the pressure-sensitive member 54 in the assembled state with respect to the valve housing 45 is set according to the degree of press-fitting of the plug body 45a into the valve portion housing 45b.

Further, as shown in FIG. 1, the first pressure chamber 5
5 is a discharge chamber 22 via a space 29a and a discharge passage 39, which is a high pressure region formed by the pressure detection port 57 formed in the plug 45a, the control valve housing portion 29, and the end surface 45d of the control valve CV.
It is in communication with. Further, the control valve housing portion 29 formed in the rear housing 4 and the outer peripheral surface of the valve portion housing 45b of the valve housing 45 form a throttle passage 59.
The throttle passage 59 constitutes a part of the refrigerant circulation circuit, and the refrigerant is discharged to the outside of the compressor, that is, the external circulation circuit 30 by the discharge port 38 communicating with the throttle passage 59. Further, a communication hole 58 communicating with the second pressure chamber 56 is provided in a part of the throttle passage 59.
Is opened at one end thereof to introduce the refrigerant decompressed in the throttle passage 59 into the second pressure chamber 56. That is, the monitoring pressure PdH is introduced to the first pressure chamber 55 that is the first pressure monitoring point P1, and the monitoring pressure PdL that is depressurized by the throttle passage 59 is supplied to the second pressure chamber 56 that is the second pressure monitoring point P2. Has been led. Therefore, the difference between PdH and PdL is the differential pressure Δ between the two points.
It becomes Pd.

As shown in FIG. 2, the solenoid portion 60 is
Is provided with a bottomed cylindrical storage cylinder 61. Container 61
A fixed iron core 62 is fitted on the upper part of the, and a solenoid chamber 63 is defined in the housing cylinder 61 by this fitting. A movable iron core 64 is housed in the solenoid chamber 63 so as to be movable in the axial direction. A guide hole 65 extending in the axial direction is formed at the center of the fixed iron core 62, and the guide rod portion 44 of the operating rod 40 is arranged in the guide hole 65 so as to be movable in the axial direction. The lower end of the guide rod portion 44 is fitted and fixed to the movable iron core 64 in the solenoid chamber 63. Therefore, the movable iron core 64 and the operating rod 40
And always move up and down together.

In the solenoid chamber 63, the fixed iron core 6
A valve element urging spring 66, which is a coil spring, is housed between the movable core 64 and the movable core 64. This valve body biasing spring 66
Acts in a direction in which the movable iron core 64 is separated from the fixed iron core 62, and urges the operating rod 40 (valve body 43) downward in the drawing.

A coil 67 is wound around the fixed iron core 62 and the movable iron core 64 in a range straddling the iron cores 62 and 64. This coil 67 is driven by the drive circuit 7 based on a command from the control device 70 in accordance with external information (vehicle compartment temperature information, set temperature information, etc.) from the external information detection means 72.
A drive signal is supplied from No. 1, and the coil 67 generates an electromagnetic attraction force (electromagnetic biasing force) having a magnitude corresponding to the amount of power supply between the movable iron core 64 and the fixed iron core 62. The energization control of the coil 67 is performed by adjusting the voltage applied to the coil 67. In the present embodiment, the coil 6
Duty control is used to adjust the voltage applied to the control circuit 7. (Operational Characteristics of Control Valve) In the control valve CV, the arrangement position of the operating rod 40, that is, the valve opening degree is determined as follows.

First, as shown in FIG. 2, when the coil 67 is not energized (duty ratio = 0%), the actuating rod 40 is arranged downwards due to the spring property of the pressure sensitive member 54 itself. The action of the urging force and the downward urging force of the valve body urging spring 66 becomes dominant. Therefore, the operating rod 40 is arranged at the lowermost moving position, and the valve body portion 43 fully opens the valve hole 47. Therefore, the crank pressure Pc becomes the maximum value that can be taken under the situation set at that time, the difference between the crank pressure Pc and the internal pressure of the cylinder bore 1a via the piston 20 is large, and the swash plate 12 has the minimum inclination angle. The compressor discharge capacity is minimal.

When the coil 67 is energized at a minimum duty ratio (> 0%) or more in the variable duty ratio range, an upward electromagnetic urging force causes a downward urging force of the pressure sensitive member 54 and the valve body urging spring 66. And the operating rod 40 starts moving upward. In this state, the upward electromagnetic urging force reduced by the downward urging force of the valve body urging spring 66 becomes the downward pressing force based on the differential pressure ΔPd between the two points urged by the downward urging force of the pressure sensitive member 54. Oppose. Then, the valve body portion 43 of the operating rod 40 is positioned with respect to the valve seat 53 at a position where these vertical urging forces are balanced.

For example, when the rotation speed of the engine E decreases and the refrigerant flow rate in the refrigerant circulation circuit decreases, the force based on the downward pressure difference ΔPd between the two points decreases, and the electromagnetic biasing force at that time causes the operating rod 40 to move. It becomes impossible to balance the vertical urging force acting on. Therefore, the operating rod 40 moves upward, and the pressure-sensitive member 54 and the valve body urging spring 66 accumulate the force.
The valve body portion 43 of the operating rod 40 is positioned at a position where the increase in the downward biasing force of 4, 66 compensates for the decrease in the force based on the downward pressure difference ΔPd between the two points.

As a result, the opening degree of the valve hole 47 decreases and the crank pressure Pc tends to decrease. The difference between the crank pressure Pc and the internal pressure of the cylinder bore 1a via the piston 20 also decreases, and the swash plate 12 tilts. By tilting in the direction of increasing the angle, the discharge capacity of the compressor is increased. When the discharge capacity of the compressor increases, the refrigerant flow rate in the refrigerant circulation circuit also increases, and the two-point differential pressure ΔPd increases.

On the contrary, when the rotation speed of the engine E increases and the refrigerant flow rate in the refrigerant circulation circuit increases, the force based on the downward pressure difference ΔPd between the two points increases, and the electromagnetic biasing force at that time causes the operation. The vertical urging force acting on the rod 40 cannot be balanced. Therefore, the actuating rod 40 moves downward, and the accumulated force of the pressure sensitive member 54 and the valve body biasing spring 66 decreases, and the decrease in the downward biasing force of both springs 54, 66 reduces the differential pressure ΔPd between the two downward points. The valve body portion 43 of the actuation rod 40 is positioned at a position that compensates for the increase in the force based on

As a result, the opening degree of the valve hole 47 increases, the crank pressure Pc tends to increase, the difference between the crank pressure Pc and the internal pressure of the cylinder bore 1a via the piston 20 also increases, and the swash plate 12 tilts. It tilts in the decreasing direction and the discharge capacity of the compressor is decreased. If the discharge capacity of the compressor decreases, the refrigerant flow rate in the refrigerant circulation circuit also decreases, and the pressure difference between the two points Δ
Pd decreases.

If, for example, the energization duty ratio to the coil 67 is increased to increase the electromagnetic biasing force, the force based on the pressure difference ΔPd between the two points at that time cannot balance the vertical biasing force. Therefore, the actuating rod 40 moves upward, and the pressure-sensitive member 54 and the valve body biasing spring 66 are accumulated, and the increase amount of the downward biasing force of both the springs 54 and 66 increases the increase amount of the upward electromagnetic biasing force. The valve body portion 43 of the actuating rod 40 is positioned at the position for compensation. Therefore, the opening degree of the control valve CV, that is, the opening degree of the valve hole 47 is decreased, and the discharge capacity of the compressor is increased. As a result, the refrigerant flow rate in the refrigerant circulation circuit increases, and the two-point differential pressure ΔPd also increases.

On the contrary, if the energization duty ratio to the coil 67 is reduced to reduce the electromagnetic biasing force, the force based on the pressure difference ΔPd between the two points at that time cannot balance the vertical biasing force. Therefore, the actuating rod 40 moves downward, and the accumulated force of the pressure-sensitive member 54 and the valve body urging spring 66 decreases, and the decrease amount of the downward urging force of the springs 54 and 66 decreases the decrease amount of the upward electromagnetic urging force. To the position for compensating
3 is positioned. Therefore, the opening degree of the valve hole 47 increases and the discharge capacity of the compressor decreases. As a result, the refrigerant flow rate in the refrigerant circulation circuit decreases, and the two-point differential pressure ΔPd also decreases.

As described above, the control valve CV includes the coil 6
In order to maintain the control target (set pressure difference) of the two-point differential pressure ΔPd determined by the energization duty ratio to 7, the actuating rod 40 is internally and autonomously changed according to the variation of the two-point differential pressure ΔPd. It is configured to be positioned. Further, this set differential pressure can be changed from the outside by adjusting the energization duty ratio to the coil 67.

The present embodiment having the above-described structure has the following effects.

(1) The throttle passage 59 is provided in the valve housing 4
5, the outer peripheral surface of the valve portion housing 45b and the control valve housing portion 29
Since it is formed on the inner peripheral surface of the pressure sensitive member 48, the pressure sensitive chamber 48 and both pressure regions 55, 56 can be brought close to each other, and the pressure sensitive member 54
It is possible to reduce the size and simplify the configuration of the control valve CV.

(2) The throttle passage 59 is formed on the inner peripheral surface of the control valve accommodating portion 29. The inner peripheral surface of the control valve accommodating portion 29 is formed with extremely high dimensional accuracy and a smooth surface (low surface roughness) for maintaining the airtightness of the compressor.
It is possible to improve the flow of the throttled refrigerant.

(3) The high pressure region PdH is not only in the first pressure chamber 55, but also in the control valve housing portion 29 and the control valve CV.
Since the control valve accommodating portion 29 is formed so that the space 29a formed by the end surface 45d of the above is also in the high pressure region PdH, the pressure detecting port 57 for introducing the refrigerant into the first pressure chamber and the throttle passage 59 can be separated, It is not necessary to provide a refrigerant passage in the pressure-sensitive member 54 itself, and it is not necessary to make both the pressure regions 55 and 56 part of the refrigerant circulation circuit. Therefore, the bellows type pressure sensitive member 54 as in the present embodiment can be applied. The bellows type pressure-sensitive member can be displaced without sliding with the inner wall surface of the pressure-sensitive chamber even if the pressure difference between the pressure chambers fluctuates. Therefore, the responsiveness due to the fluctuation of the differential pressure can be enhanced.

(4) Since the filter 45e is provided on the end surface 45d of the control valve CV, it is possible to prevent foreign matter from entering the pressure-sensitive chamber 48 and to prevent a decrease in responsiveness of the capacity change due to foreign matter. it can. Second Embodiment A control valve of the second embodiment will be described with reference to FIGS. 3 and 4. In this embodiment, the valve housing 4
No. 5 valve housing 45b and end face 45d of control valve CV
A casing 49 is coated on the outer periphery of the. The casing 49 has a certain gap between the valve portion housing 45b of the valve housing 45 and the end surface 45d of the control valve CV, and is a bottomed cylindrical tubular body having a hole in the bottom surface.
5 is joined and fixed to a part of the valve portion housing 45b. That is, in this embodiment, this gap serves as the throttle passage 59. Further, an introduction hole 49a is formed on the bottom surface of the casing 49, and a discharge hole 49b communicating with the discharge port 38 is formed on a part of the peripheral surface, forming a part of the refrigerant circulation circuit.
In the present embodiment, the filter 45e is arranged on the end surface of the casing 49.

In this embodiment, the same effect as (1) of the first embodiment is obtained. In addition, the following effects are achieved.

(1) Since the valve housing 45b of the valve housing 45 is covered with the casing 49, the pressure detecting port 57 for introducing the refrigerant into the first pressure chamber and the throttle passage 59 can be separately provided, and the pressure sensitive member 54 can be provided. It is not necessary to provide a refrigerant passage in itself, and it is not necessary to make both pressure regions 55 and 56 part of the refrigerant circulation circuit. Therefore, the bellows type pressure sensitive member 54 as in the present embodiment can be applied. The bellows type pressure-sensitive member can be displaced without sliding with the inner wall surface of the pressure-sensitive chamber even if the pressure difference between the pressure chambers fluctuates. Therefore, the responsiveness due to the fluctuation of the differential pressure can be enhanced. (2) Since the casing 49 is arranged between the inner peripheral surface of the control valve accommodating portion 29 and the valve portion housing 45b of the valve housing 45, the width of the throttle passage 59 can be freely changed by changing the thickness of the casing 49. That is, the aperture amount can be changed.

(3) Since the filter 45e is provided on the end surface of the casing 49, it is possible to prevent foreign matter from entering the pressure-sensitive chamber 48, and to prevent a decrease in responsiveness of the capacity change due to foreign matter.

Third Embodiment A control valve according to the third embodiment will be described with reference to FIGS. In this embodiment, the valve housing 4
A communication passage 81 that opens to the end surface 45d of the control valve CV and the port 51 is formed in the valve portion housing 45b of No. 5.
Therefore, the port 52 becomes the discharge pressure region, and the port 51 communicates with the crank chamber 5. In the present embodiment, the communication passage 81, the port 52, the valve hole 47, the valve chamber 46, and the port 51 constitute a part of the air supply passage 28 that connects the discharge chamber 22 and the crank chamber 5 as a control valve internal passage. To do. The communication passage 81 is covered with a filter 45e that covers the end surface of the valve housing 45.

In the control valve of the third embodiment shown in FIG. 6, the rotational speed of the engine E decreases, the force based on the downward pressure difference ΔPd between the two points decreases, and the electromagnetic valve at that time decreases. The urging force cannot balance the vertical urging force acting on the operating rod 40, and the valve body portion 43 of the operating rod 40 has moved to the uppermost position where it is seated on the valve seat 53. At this time, the valve hole 47 is closed and the crank chamber 5
And the discharge chamber 22 are not in communication with each other. Therefore, as the crank pressure Pc decreases, the discharge capacity increases.

In this embodiment, the same effects as (1), (2) and (3) of the first embodiment can be obtained. In addition, the following effects are achieved.

(1) Since the communication passage 81 is arranged in the valve portion housing 45b of the valve housing 45, the number of air supply passages 28 formed in the housing of the variable displacement compressor can be reduced, and the air supply passages can be reduced. It becomes easy to form 28.

(2) Since the filter 45e is provided on the end surface 45d of the control valve CV, foreign matter is prevented from entering the pressure sensing chamber 48 and the communication passage 81, and the response of the capacity change due to the foreign matter is reduced. Can be prevented.

It should be noted that, for example, the following embodiments can be carried out without departing from the spirit of the present invention.

In the above embodiments, the pressure sensitive member 5
Although the bellows type is used for 4, a diaphragm type may be used. Even with this structure, the same effect can be obtained.

In each of the above embodiments, the throttle passage 59
Of the valve housing 45 of the valve housing 45
Additional machining of the outer peripheral surface of b and the inner peripheral surface of the control valve accommodating portion 29 or the inner peripheral surface of the casing 49. In this aspect, the oil separator function can be provided by adjusting the flow of the refrigerant. In this case, it is necessary to provide an oil return passage that connects the crank chamber 5 and the throttle passage 59 in the housing of the compressor.

In each of the above embodiments, the first pressure chamber 5
Although 5 is a high pressure region and the second pressure chamber 56 is a low pressure region, the first pressure chamber 55 is a low pressure region and the second pressure chamber 56 is a high pressure region. In this aspect, the vertical positional relationship between the valve hole 47 and the valve chamber 46 in the valve housing 45 is the reverse of the aspect of each embodiment.

In each of the above embodiments, the control valve CV
Adjusts the pressure of the crank chamber 5 by a so-called inlet-side control that changes the opening of the air supply passage 28, but adjusts the pressure of the crank chamber by a so-called extraction-side control that changes the opening of the extraction passage 27. Good.

In the third embodiment, the communication passage 81 communicates the space 29a with the port 52.
9 may be shared as a part of the communication passage 81. By doing so, the processing range of the valve housing 45b can be reduced.

Embodying the present invention in a wobble type variable capacity compressor.

The technical idea that can be understood from the above-described embodiments will be described.

(1) The control valve according to any one of claims 1 to 6, wherein the displacement control of the variable displacement compressor is a so-called inlet side control for changing the opening of the air supply passage.

(2) The control valve according to any one of claims 1 to 6, wherein the displacement control of the variable displacement compressor is a so-called withdrawal side control for changing the opening of the extraction passage.

[0069]

According to the present invention having the above-described structure, it is an object of the present invention to provide a control valve capable of feedback controlling the compression discharge capacity with a simple structure.

[Brief description of drawings]

FIG. 1 is a sectional view of a variable displacement compressor according to a first embodiment.

FIG. 2 is an enlarged view of a control valve according to the first embodiment.

FIG. 3 is a sectional view of a variable displacement compressor according to a second embodiment.

FIG. 4 is an enlarged view of a control valve according to the second embodiment.

FIG. 5 is a sectional view of a variable displacement compressor according to a third embodiment.

FIG. 6 is an enlarged view of a control valve according to a third embodiment.

[Explanation of symbols]

5 ... Crank chamber, 21 ... Suction chamber as suction pressure region,
22 ... Discharge chamber as discharge pressure region, 27 ... Extraction passage,
28 ... Air supply passage, 29 ... Control valve accommodating portion, 43 ... Valve body portion of operating rod as valve body, 45 ... Valve housing, 4
6 ... Valve chamber, 48 ... Pressure sensing chamber, 49 ... Casing, 54 ... Pressure sensing member, 55 ... First pressure chamber, 56 ... Second pressure chamber, 59 ...
Throttle passage, 60 ... solenoid part constituting external control means, PdH ... pressure in high pressure region, PdL ... pressure in low pressure region, Pc ... pressure in crank chamber, CV ... control valve.

Continued front page    F term (reference) 3H045 AA04 AA10 AA12 AA27 BA19                       CA02 CA03 CA29 DA25 EA13                       EA26 EA33                 3H076 AA06 BB33 BB41 CC12 CC20                       CC84

Claims (6)

[Claims] 1. A control valve used in a variable displacement compressor that constitutes a refrigerant circulation circuit of an air conditioner and is capable of changing a discharge capacity based on a pressure of a control pressure chamber formed inside a housing, wherein the variable capacity is used. A valve housing that is housed in the control valve housing of the housing of the compressor and forms the outer contour of the control valve; and a supply passage that connects the control pressure chamber of the variable capacity compressor and the discharge pressure region of the refrigerant circulation circuit, Alternatively, a valve chamber partitioned within the valve housing to form a part of the extraction passage that connects the control pressure chamber and the suction pressure region of the refrigerant circulation circuit, and the valve chamber is displaceably accommodated in the valve chamber, A valve body capable of adjusting the opening degree of the air supply passage or the extraction passage according to the position, a pressure sensitive chamber formed in the valve housing, and a high pressure inside the pressure sensitive chamber operatively connected to the valve body. Through the area and throttle passage A pressure sensitive member that is divided into a discharge pressure region or a low pressure region that communicates with the suction pressure region, and the displacement of the pressure sensitive member based on fluctuations in the pressure difference between the high pressure region and the low pressure region is Reflected in body positioning,
In order to change the discharge capacity of the variable displacement compressor, the valve body moves to the side that cancels the fluctuation of the same pressure difference, and the throttle passage forming a part of the refrigerant circulation circuit is a pressure sensitive chamber part. Of the valve housing and the inner peripheral surface of the valve housing accommodating portion of the pressure sensing chamber portion. 2. The control valve according to claim 1, wherein an inner peripheral surface of the valve housing accommodating portion of the pressure sensing chamber portion is constituted by an inner peripheral surface of the control valve accommodating portion. 3. The control according to claim 1, wherein the inner peripheral surface of the valve housing accommodating chamber of the pressure sensitive chamber portion is formed of an inner peripheral surface of a casing disposed on the outer periphery of the valve housing of the pressure sensitive chamber portion. valve. 4. The control valve accommodating portion is formed such that the space formed by the valve housing accommodating portion of the pressure sensing chamber portion and the end surface of the control valve is also in a high pressure region or a low pressure region.
The control valve according to any one of 3 to 3. 5. The communication passage according to claim 1, wherein the valve housing is formed with a communication passage that communicates the high pressure region or the low pressure region with the supply passage or the extraction passage formed in the valve chamber. Control valve. 6. A filter for preventing foreign matter from being mixed into the pressure-sensitive chamber or the communication passage, or both, on at least a part of the end surface of the control valve.
The control valve according to any one of 1.