DE102007028340A1 - Control valve for compressor with variable displacement, has body, where coolant passage is provided inside lying section, valve element arranged to form valve opening and electromagnets to provide differential pressure in axial direction - Google Patents

Abstract

The control valve (1) has a body (31), where a coolant passage is provided in an inside lying section. A valve element (18) is provided, which is arranged to form a valve opening (15). The coolant passage brings the discharge opening chamber and the crank case in the way of connection flow to open and close a valve section. A shaft is provided, where in an axial direction a force is transferred toward the valve element. The electromagnets are provided in the closing direction of the valve to provide differential pressure in the axial direction.

Description

General to the invention

1. Technical area

The The present invention relates to a control valve for a Adjustable compressor and in particular a control valve, that is preferably for controlling a delivery capacity of an adjustable compressor can be used, which is a cooling circuit for one Air conditioning in a motor vehicle builds.

2. State of the art

The Air conditioning for the motor vehicle is generally equipped with a compressor which a coolant, flowing through a cooling circuit, so compressed, that a gaseous coolant is discharged at a high temperature and under high pressure, wherein a condenser is the gaseous one coolant compressed and wherein an expansion device condensed liquid Coolant adiabatic decompressed to eo a coolant to obtain, which has a low temperature and low Pressure stops while an evaporator the coolant evaporated in such a way that a heat exchange with the air in the Passenger compartment or the like takes place., Which evaporated from the evaporator coolant is returned to the compressor, so that it is in the cooling circuit circulated.

There the compressor has a motor in which a rotational speed in correspondence with a driving state of a vehicle as a drive source changed it will be impossible to carry out a control of the rotational speed. To now independently from the rotational speed of the engine, a suitable cooling capacity a variable displacement compressor (or: an adjustable compressor) used in which a flow rate of the coolant varies.

at The above compressor is a compression piston with coupled to a swash plate attached to a shaft, which is driven by the motor for rotation. Furthermore is the structure is held so that it has an outlet amount of the coolant through change a stroke of the piston governs by an angle of the swash plate changed becomes. The angle of the swash plate can be opened by introducing a Part of the funded refrigerant in the sealed crankcase and by changing a pressure equalization made on both surfaces of the piston will, continuously change. The inside of the crankcase prevailing pressure is controlled by a control valve that between an outlet chamber and a crankcase of the compressor or between the crankcase and a suction chamber is provided.

As the aforementioned control valve, for example, there is provided a structure which controls an amount of the refrigerant introduced into the crankcase in accordance with a differential pressure (Pd-Ps) between a discharge pressure Pd and a suction pressure Ps, and also a pressure Pc (hereinafter referred to as " Crankcase pressure "), which prevails inside the crankcase (as an example is here on the Japanese Patent Laid-Open Publication No. 2001-132650 ( 4 ).).

The Control valve is constructed in such a way that it controls in the form that a valve portion, the flow connection through a Passage between the outlet chamber and the crankcase releases or locks, opens or close, so that the differential pressure (Pd - Ps) between the delivery pressure Pd and the suction pressure Ps at a preset value for the differential pressure is held; the control valve is also equipped with an electromagnet provided, a driving force in the opening and closing direction generated, based on a valve element in its inner region. The preset differential pressure is designed to be from one from the outside supplied to the solenoid valve Electricity changed becomes. If also the coolant capacity is increased and the differential pressure (Pd - Ps) greater than becomes the preset value of the differential pressure becomes the opening degree bigger and bigger the crankcase pressure increases PC on. As a result, an inclination angle of the swash plate becomes smaller and is made smaller by expanding the stroke of the piston, which also causes the production capacity is smaller becomes. Accordingly, the differential pressure (Pd-Ps) becomes smaller, so that it approaches a value close to the preset differential pressure changed. If on the other hand, the amount of coolant is reduced and the differential pressure (Pd - Ps lower than the preset Differential pressure is, the degree of opening of the valve is smaller and becomes the crankcase pressure Pc reduced. As a result, the inclination angle of the swash plate becomes bigger and Also, the stroke of the piston becomes larger due to expansion, thereby the production capacity becomes larger. Accordingly, the differential pressure (Pd-Ps) becomes larger and changes to a value close to the preset differential pressure.

On this way it is possible the differential pressure (Pd - Ps) on a desired Control differential pressure by the preset differential pressure is regulated; It is also possible, the flow rate of the coolant to regulate from the compressor in a suitable manner.

In addition, according to the above is described autonomously controlled in such a manner that the opening degree of the valve is changed so that the differential pressure (Pd - Ps changes to the preset value of the differential pressure out, and further there on the basis of a size of the delivery pressure Pd itself a quantity control is made, this provides an advantage in that a good response is achieved to change the production capacity.

In this case, when the compressor in the refrigeration cycle is started as described above, so-called soft start occurs in that the differential pressure (Pd-Ps from the control valve changes from a state of about zero to the preset differential pressure in small steps becomes. 29 FIG. 14 is an explanatory diagram showing the state of change of the delivery pressure and the intake pressure starting from a time point at which the conventional variable displacement compressor is started. FIG. In this drawing, a horizontal axis indicates a time t passing from the start time, while a vertical axis indicates the discharge pressure Pd and the suction pressure Ps. In addition, a dotted line in the drawing indicates a Variegated tion of the discharge pressure Pd, while a solid line indicates a change in the suction pressure Ps.

With In other words, in the case that the electromagnet of the Control valve no power supplied is - i. in the case of a minimum capacity operation in which the function of the compressor essentially comes to a standstill - to one State in which the differential pressure (Pd-Ps is approximately zero.) As shown it comes at this time at the delivery pressure Pd and the suction pressure Ps at about the same pressure level.

If then supplied to the electromagnet power and the compressor started is a regulation is made insofar as by the scheme the supplied Amount of current the differential pressure (Pd - Ps in small steps always gets higher and reaches a value close to the preset differential pressure. In this case, the preset differential pressure is regulated by that supplied to the solenoid valve Amount of electricity based on various external information by means of a Control device changed being in an outside lying part of the control valve is installed.

Around however, the cooling capacity increase, for example, when the differential pressure (Pd - Ps) high is, as shown by a dashed line in the drawing is, and the suction pressure Ps is reduced too much, then the temperature of the evaporator, which is proportional to it, lower. In other words, there is a risk that by too much cooling Freezing of the evaporator is caused and the cooling capacity is significantly reduced. On the other hand, the autonomous control keeps the Adjustment of the differential pressure (Pd - Ps) to the preset value Value of the differential pressure in the manner described above not the Suction pressure Ps at a value equal to a set value is or above lies. In other words, receives Do not start an operation for adjusting the suction pressure Ps the predetermined value or above simply by making a control on the preset differential pressure (Pd - Ps) becomes; When the suction pressure Ps decreases, while the differential pressure (Pd-Ps constant is held, there is a possibility that too much cooling effect is produced.

Accordingly An outlet temperature of the evaporator is generally detected and returned to the control device. When the outlet temperature of the evaporator becomes lower than one given reference value, the control device takes the control in such a way that an excessive increase of the suction pressure Ps is prevented by the amount of electricity supplied to the electromagnet is controlled so that the preset differential pressure is low becomes. As a result, change the delivery pressure Pd and the suction pressure Ps and are controlled so that they are close to the Preset value of the differential pressure are what's in the drawing represented by a dotted line and a solid line becomes; This prevents the evaporator from freezing. In this Fall presses the double-dotted line in the drawing has a pressure value Pmin from that mentioned above Reference value corresponds to the outlet temperature of the evaporator.

If however, the regulation under continuous monitoring of the outlet temperature is made of the evaporator, the suction pressure Ps learns repeatedly a comparatively large fluctuation near the pressure value, which corresponds to the reference value of the outlet temperature. Accordingly, one gets in the face stability and a response of the controller preferably autonomously Characteristic in the form that the suction pressure Ps at a value is held, which is equal to or above the pressure value Pmin.

The problems described above should also be present in a similar form in the control valve, which operates with the control method in which the differential pressure between two predetermined points in the cooling circuit is maintained at the preset value of the differential pressure. The same problem arises, for example, in the control valve, which in the way before a control assumes that a flow rate of the refrigerant discharged from the compressor becomes constant, to which a differential pressure value between a pressure value (Pdh) in an outlet chamber of the compressor and a pressure value (Pdl) in an outlet of the compressor is set to a preset differential pressure value.

Brief description of the invention

The The present invention has been made in consideration of the above developed problem; an object of the present Invention is possible to make that a freeze of an evaporator or a similar phenomenon in a control valve, the displacement control based on a differential pressure between two points in a cooling circuit an air conditioner for a motor vehicle, is automatically prevented.

to solution The above object is a control valve for a Compressor with variable displacement or flow rate (or: an adjustable compressor) according to a particular aspect of stimulated the present invention, which is the Durchatz of a an exhaust chamber introduced into a crankcase coolant in the way controls (or: regulates) that a differential pressure between two predetermined points is kept in a cooling circuit and a output of the coolant changed from the compressor becomes. The control valve has the following: a body (or: Body), in which a coolant passage is formed in an inner portion is; a valve element arranged in such a way that it to a valve opening close down and can move away from this, which forms the coolant passage, the brings the outlet chamber and the crankcase in fluid communication, so that a valve section is opened and closed; a shaft, which in the axial direction a Transfers force to the valve element; one Electromagnet, which in the valve closing direction, the on the Corresponds to the shaft-acting preset differential pressure in the axial direction, a force of the electromagnet exerts and the valve element in the opening and closing direction the valve portion is actuated; a pressure chamber, that of an inside and of the carcass and the electromagnet enclosed space is formed and with a suction chamber or the crankcase is in flow communication, so that in one of the two rooms a pressure is initiated or can be introduced; and a pressure sensing section, which is provided inside the body or integral with the body is formed so as to have a pressure prevailing in the pressure chamber to capture, and which generates a force in a direction in which the Power of the electromagnet is reduced when in the pressure chamber prevailing pressure is lower than the preset pressure.

In this case can also be for the term "differential pressure between two predetermined points "for example a" differential pressure between a delivery pressure in the outlet chamber and a suction pressure in the suction chamber. In this case, the structure may be provided in such a way that the pressure chamber in fluid communication is brought with the suction chamber, so as to initiate the suction pressure. Alternatively, for the term "differential pressure between two given points "also, for example, a" differential pressure between a prevailing pressure in the outlet chamber and a in an outlet of the compressor prevailing pressure In this case, the structure may be provided in such a manner that the Pressure chamber so with the crankcase in fluid communication is brought that the crankcase pressure is introduced.

According to this Aspect the pressure prevailing in the pressure chamber is monitored while one Control of the original Displacement is made to the differential pressure between two points to keep at the preset value of the differential pressure; if the pressure in the pressure chamber then lower than the preset Pressure, the pressure sensing section generates the force in one Direction in which the force of the electromagnet is reduced.

With In other words, in the case that the pressure chamber with the Suction chamber in flow connection the pressure detecting section is the suction pressure. As the suction pressure roughly in proportion is the outlet temperature of the evaporator in the cooling circuit, is the low suction pressure is an indication that the outlet temperature of the evaporator is low. The delivery capacity or discharge volume of the compressor is, as already explained above, reduced by applying the force in the direction in which the force of the electromagnet becomes lower when the suction pressure lower than the preset pressure value, so it is on this Way becomes easy to open the valve section, resulting in an excessively strong Cooling prevent it.

In addition, in the case where the pressure chamber is in fluid communication with the crankcase, the pressure detecting portion detects the crankcase pressure. Since the crankcase pressure and the intake pressure are generally not different, in the case where the crankcase pressure is low, the outlet temperature of the evaporator is lower. As already stated, the conveying capacity of the compressor is thereby verrin that the force of the solenoid is reduced to make it easy to open the valve portion when the crankcase pressure becomes lower than the preset pressure value, thereby preventing excessive cooling.

There the quantity control automatically is made by the pressure sensing section the detected in the pressure chamber prevailing pressure, it is possible that Freezing or similar phenomena to effectively prevent the evaporator. In addition, because the pressure sensing section is formed inside the carcass or integral with the carcass, can be achieved that the control valve the above Having control characteristic with a simple structure.

One Another aspect of the present invention also relates to a control valve for one adjustable compressor. This control valve controls a throughput one introduced from the outlet chamber of the compressor in a crankcase refrigerant and changed a capacity of the compressor. The control valve has the following: a body in which formed in an inner portion of a coolant passage is; a valve element arranged in such a way that it that it is a valve opening close down and can move away from this, which forms the coolant passage, the the outlet chamber and the crankcase are thus in fluid communication brings, so that a valve section is opened and closed; a shaft which transmits a force to the valve element in the axial direction; one Electromagnet, which is capable in the valve closing direction of the valve portion to the shaft a force of the electromagnet apply and while the valve element in the opening and closing direction to actuate the valve section; a pressure chamber connected to a suction chamber or the crankcase of the Compressor in flow connection stands, so that in one of the two parts of a pressure is initiated or can be introduced; and a pressure detection section, which is incorporated in Interior of the carcass provided or integral with the carcass in the Is formed such that it prevails one in the pressure chamber Detects pressure and generates a force in one direction, in which the force of the electromagnet is reduced when in the pressure chamber prevailing pressure is lower than the preset pressure.

Also according to this Aspect will increase the capacity of the compressor decreases and becomes an overly strong cooling prevented by applying the force in the direction in the force of the electromagnet is reduced when the suction pressure or the crankcase pressure lower than the preset pressure value will allow the valve element open in this way easier leaves.

Instead of a "control" can in all embodiments also a "rules" be provided.

Brief description of the drawings

1 is a cross-sectional view showing the structure of a control valve according to a first embodiment;

2 is a view for explaining an operation of the control valve;

3 is a view for explaining the operation of the control valve;

4 is a view for explaining the operation of the control valve;

5 is a view for explaining the operation of the control valve;

6 Fig. 15 is a view for explaining a state of change of a discharge pressure and a suction pressure from the time when the compressor is started;

7 is a cross-sectional view showing the structure of a control valve according to a second embodiment;

8th shows a partially enlarged sectional view of an upper half 7 corresponds;

9 is a cross-sectional view showing the structure of a control valve according to a third embodiment;

10 shows a partially enlarged sectional view of an upper half 9 corresponds;

11 is a cross-sectional view showing the structure of a control valve according to a fourth embodiment;

12 shows a partially enlarged sectional view of an upper half 11 corresponds;

13 FIG. 12 is a cross-sectional view showing the structure of a control valve according to a fifth embodiment; FIG.

14 is a view for explaining the operation of the control valve;

15 is a view for explaining the Operation of the control valve;

16 is a cross-sectional view showing the structure of a control valve according to a sixth embodiment;

17 shows a partially enlarged sectional view of an upper half 16 corresponds;

18 FIG. 15 is a cross-sectional view showing the structure of a control valve according to a seventh embodiment; FIG.

19 shows a partially enlarged sectional view of an upper half 18 corresponds;

20 FIG. 12 is a cross-sectional view showing the structure of a control valve according to an eighth embodiment; FIG.

21 shows a partially enlarged sectional view of an upper half of the control valve 20 corresponds;

22 is a view for explaining the operation of the control valve;

23 is a view for explaining the operation of the control valve;

24 is a view for explaining the operation of the control valve;

25 is a cross-sectional view showing the structure of a control valve according to a ninth embodiment;

26 shows a partially enlarged sectional view of an upper half of the control valve 25 corresponds;

27 FIG. 10 is a cross-sectional view showing the structure of a control valve according to a tenth embodiment; FIG.

28 shows a partially enlarged sectional view of an upper half of 27 corresponds; and

29 FIG. 14 is a view for explaining a state of change of a discharge pressure and a suction pressure from the time when the compressor is started. FIG.

Detailed description of the invention

below the invention will now be described with reference to the preferred embodiments described. This is not intended to limit the scope of the invention, rather, it should be described as an example.

below Will now be exemplary embodiments of the present invention with reference to the attached Drawings in detail described. In this case, for the sake of simplified illustration in the following description, a relationship in the position of each Construction with "upper Side "and" lower Page "based expressed state of the illustrated state.

First embodiment

1 shows a cross-sectional view showing the structure of a control valve according to a first embodiment.

There is a control valve 1 for an adjustable compressor constructed as a so-called Pd-Ps valve, which controls the flow rate of a coolant, which is introduced from a discharge chamber in a crankcase in such a way that between a discharge pressure Pd and a suction pressure Ps of (not shown here) Compressor maintained a differential pressure (Pd - Ps) to a preset value of the differential pressure.

The control valve 1 is constructed by having a valve main body 2 and an electromagnet 3 via a connecting element 4 be mounted integrally. The valve main body 2 opens and closes a coolant passage for introducing a charge of a conveyed coolant into the crankcase. The solenoid valve 3 regulates the degree of opening of a Ventilab section of the valve main body 2 so as to control the flow rate of the refrigerant introduced into the crankcase.

The main valve body 2 is with a stepped cylindrical body 5 one inside the body 5 arranged valve mechanism, a pressure sensing part 6 , which will be described later and performs the operation of the valve mechanism, and the like.

An upper section of the body 5 is with a passage 11 provided which is in flow communication with the outlet chamber of the compressor so that it takes over the delivery pressure Pd. The passage 11 stands with a passage 13 in fluid communication, in its lateral portion of the carcass 5 in an interior of the same. The passage 13 is in fluid communication with the crankcase of the compressor and directs a controlled crankcase pressure Pc out to the crankcase.

Am cylindrical part 14 , which forms a valve seat, is fitted in a coolant line under pressure, which the passage 11 with the passage 13 connects, while an internal passage of the part a valve opening 15 forms. In addition, from an end face of the valve seat forming part 14 on the side of the crankcase a valve seat 16 educated.

Furthermore, in the valve seat 16 a valve element 18 that from one end section of a long operating rod 17 is formed, arranged in such a way that it faces the crankcase side so that it can unhindered close to this and open away from this. The valve element 18 is displaceable on a guide hole 19 stored in the middle of the carcass 5 is provided. The valve element 18 is in a pressure chamber 21 arranged on a downstream side of the valve opening 15 is in flow communication with the crankcase, while an outer peripheral edge of its front end surface to the valve seat 16 is movable towards and away from it, causing the valve opening 15 opened and closed.

A passage 22 , which communicates with the suction chamber of the compressor in fluid communication so as to take on the suction pressure Ps, is formed at a position outside at a bottom for discharging from a passage 13 in its lateral section of the corpus 5 lies, and stands with an opening 24 in fluid communication, in the middle at a lower end of the carcass 5 is provided and has a predetermined depth. An inside room, that of the body 5 and the electromagnet is enclosed and its opening 24 positioned thereon forms a pressure chamber 25 into which the suction pressure Ps is introduced. The suction pressure Ps is also applied to an inner portion of the electromagnet 3 directed. A pressure sensing part 6 serving as a pressure detecting section which detects the suction pressure Ps for the operation is in the pressure chamber 25 arranged. A feather 26 clamps the pressure sensing part 6 to the side of the electromagnet 3 and is between the pressure sensing part 6 and the body 5 arranged. Details of the pressure sensing part 6 will be described in detail below.

The body 5 is over the stepped cylindrical connecting element 4 connected to the electromagnet. In this case, an upper end portion of the connecting element under pressure in the opening 24 fitted.

The electromagnet 3 on the other hand, with a housing 31 which serves as a yoke, and further comprises: a core 32 inside the case 31 attached, a voice coil 33 , which is arranged so that it is in the axial direction of the core 32 opposite, and a plunger 34 which builds a magnetic circuit by means of a current supplied from an external part. An upper end portion of the housing 31 is by caulking at a lower end portion of the connecting part 4 attached.

An upper end portion of the core 32 is under pressure in an inner circumferential surface of the connecting part 4 fitted. The core 32 is with an insertion hole 35 provided by the center of the core 32 in the axial direction, while a shaft 20 for transmitting a force of the electromagnet to the valve element 18 in the core 32 is used. Because between the upper end portion of the core 32 and the wave 20 a predetermined play is provided, the structure is designed so that the suction pressure Ps in the interior of the pressure chamber 25 also about the clearance in the inner area of the electromagnet 3 is initiated.

Furthermore, there is a sleeve 36 with closed end, which has a closed lower end and the outside in the core 32 is introduced. The plunger coil 33 is inside the sleeve 36 with the closed end arranged so that it is in the axial direction in a bottom of the core 32 is movable forwards and backwards. An upper end portion of the sleeve 36 with closed end is in a lower half section of the connecting element 4 fitted under pressure. In addition, in a lower end portion inside the sleeve 36 with closed end a bearing part 37 fixedly disposed while a lower end portion of the shaft 20 is slidably mounted.

The wave 20 is in a lower section with a part 38 provided with a small diameter whose diameter is reduced in one state, wherein the plunger coil 33 located outside and in a bottom of a portion near a base end portion of the part 38 used with a small diameter. A front end of the part 38 with a small diameter is sliding in the bearing part 37 inserted.

The plunger coil 33 is formed in the stepped cylindrical member and the shaft 20 gets from a stepped round hole 42 is inserted, which is formed in the middle of an upper portion thereof. A feather 46 which the plunger coil 33 in one direction, in which the plunger coils 33 from the core 32 is moved away, is between the core 32 and the plunger coil 33 used. Furthermore, a spring spans 47 the plunger coil 33 in a direction in which the plunger coil 33 close to the core 32 moves, and is in between the plunger coil 33 and the bearing part 37 used. The spring tension of the springs 46 and 47 can be adjusted by placing it on the underside of the sleeve 36 is pressed with its closed end from the outer portion, so that it deforms and the bearing part 37 relocated.

Next, the structure and operation of the printer sensing part will be described in detail. 2 to 5 FIG. 3 are explanatory views illustrating an operation of the control valve and corresponding to the partially enlarged views corresponding to an upper half portion in FIG 1 are assigned. 2 FIG. 10 illustrates a state in which a differential pressure (Pd-Ps) is less than a preset differential pressure, and the suction pressure Ps is greater than a preset pressure value. 3 represents a state in which the differential pressure (Pd-Ps) is higher than the preset differential pressure while the suction pressure Ps is higher than the preset pressure value. 4 shows a state during a transitional period in which the suction pressure Ps becomes just lower than the preset pressure during the control of the differential pressure (Pd-Ps). And 5 FIG. 14 shows a state in which, during the control of the differential pressure (Pd-Ps), the suction pressure Ps is lower than the preset pressure.

As 2 shows is the pressure sensing part 6 with a hollow case 51 provided that between the operating rod 17 and the wave 20 is used and stored so that it is displaceable in the opening and closing direction of the valve element; There is a membrane 52 arranged in a manner that it divides an inside of the housing in a sealed space S1 and an open space S2 and acts as a flexible part, wherein in the sealed space S1, a spring 53 is arranged, which acts as an elastic part, and an element 55 is housed for transmitting a reaction force in the open space S2 and three leg portions 54 extending to an upper side while passing through the housing 51 pass through. The open space S2 is connected to the pressure chamber 25 in fluid communication.

The housing 51 is from a first case 56 and a second housing 57 formed, both of which are made of stainless steel and formed in a closed-end shape; the housing is assembled in such a way that an outer edge portion of the membrane 52 , which is formed by a thin metal plate in its outer edge region, wherein the opening portions face each other, is clamped. The housing 51 is formed in a container shape by laying a weld along the outer circumference in a state where the membrane is located along a joint portion 52 between the first housing 56 and the second housing 57 is held. Since the welding work is carried out in a negative pressure atmosphere, the sealed space S1 becomes a negative pressure state, but the construction may be designed to fill the inside of the sealed space S1 with ambient lift or the like.

The middle of a lower section in the membrane 52 in the first case 56 opposite side is formed flat and supports a lower end portion of the actuating rod 17 (ie, an end portion on the valve element 18 from the underside of opposite side). In addition, at three positions, which are the actuating rod 17 Surrounded in the shallow section, passages 61 formed, which up to the side of the valve element 18 protrude while passing each through three leg sections 54 of the element 55 led to the transmission of the reaction force. An inside section of the first housing 56 stands with the pressure chamber 25 over the passage 61 in flow communication; the suction pressure Ps is introduced therethrough. Accordingly, the membrane captures 52 the suction pressure Ps in such a manner that it expands and contracts in the opening and closing direction of the valve portion.

On the other hand, in the middle of the lower portion on the opposite side of the membrane 52 in the second housing 52 under pressure forming a concave shaft coupling section 62 formed while an upper end portion of the shaft 20 is loosely fitted. The housing 51 is, as already stated, used in such a way that it is between the actuating rod 17 and the wave 20 is clamped and supported so that it is displaceable in the opening and closing direction of the valve section.

A disk 63 made of stainless steel is attached to a surface of the membrane 52 on the side of the second housing 57 welded, while a spring to regulate a preset load 53 between the disc 63 and the second housing 57 is used. Matched concave and tapered shapes are for centering the disc 63 in respective central regions of the membrane 52 and the disc 63 intended.

An element 55 for transferring the reaction force made of stainless steel, to a central portion of the surface of the membrane 52 on the side of the first case 56 welded. leg sections 54 are at three positions of an outer peripheral portion of the element 55 vorgese to transfer a reaction force hen that they become a top (that is, one of the membrane 52 opposite side) and from the implementation 61 of the first housing 56 protrude. The leg sections 54 are designed to be one of the wave 20 in the body 5 towards and away from the movable surface, that is, to or from a bottom 64 the opening 24 , Furthermore, between the first housing 56 and the body 5 a feather 26 used, which the pressure sensing part 6 clamped in the valve opening direction.

In this case, the membrane deforms 52 to the side of the valve element 18 when the suction pressure Ps inside the pressure chamber 25 becomes lower than a predetermined and preset pressure value Pset while the leg portion 54 of the element 55 for transmitting the reaction force to the bottom 64 suppressed. As a result, the on the element 55 reaction force acting on the membrane to transmit a reaction force 52 , the disc 63 , the feather 53 and the second housing 57 on the wave 20 while a force is applied in the direction in which the force of the electromagnet Fs decreases. The preset pressure value Pset is fundamentally previously based on a spring force of the spring 53 and regulated by a relationship between the temperature inside the evaporator and the suction pressure Ps as a pressure value that can prevent the evaporator from freezing.

• 1) Im Falle von Ps > Pset A(Pd – Ps) = Fs – F2 (1)
• 2) Im Falle von Ps < Pset A(Pd – Ps) + F2 – Fs – B·Ps + F1 = 0.

Assuming that in the construction shown above, the reference numeral A is a surface of the valve element 18 for effective pressure transfer (ie a cross-sectional area of the valve opening 15 ), according to 1 the reference character B is a surface for the effective pressure takeover of the pressure detecting part 6 (ie an area on the membrane 52 for effective pressure take-up), while the reference character Fs indicates a force of the electromagnet, that of the electromagnet 34 is generated, and the reference character F1 denotes a force which is the spring 53 of the pressure sensing part 6 is produced; reference character F2 indicates a resultant force in the valve opening direction provided by the springs 26 . 46 and 47 is produced; a relation for the balance of forces is roughly expressed by the following expressions (1) and (2).

• 1) In the case of Ps> Pset A (Pd - Ps) = Fs - F2 (1)
• 2) In the case of Ps <Pset A (Pd - Ps) + F2 - Fs - B · Ps + F1 = 0.

In this case, the following expression results because the control process is carried out in such a way as to establish a relation Ps = Pset: Pset = (A * Pd + F2 + F1-Fs) / (A + B) (2).

• 1) In dem Fall, dass der Ansaugdruck Ps größer als der eingestellte Druck Pset ist, ist der Schenkelabschnitt 54 von der Unterseite 64 des Korpus 5 abgehoben, wie dies in 2 und 3 dargestellt ist. Dementsprechend dient, wie in der obigen Beziehung (1) aufgezeigt, das Steuerventil 1 als so genanntes Pd-Ps-Ventil, welches den Differenzdruck (Pd – Ps) auf dem voreingestellten Wert für den Differenzdruck hält. Da die resultierende Kraft F2 der Federn in der vorstehenden Beziehung (1) festgelegt ist, ist es möglich, den voreingestellten Wert des Differenzdrucks dadurch zu verändern, dass der Wert des dem Elektromagneten 3 zugeführten elektrischen Stroms so verändert wird, dass die Kraft Fs des Elektromagneten geregelt wird. 3 stellt einen Zustand dar, in dem der Ventilabschnitt infolge der Erhöhung des Differenzdrucks (Pd – Ps) über den voreingestellten Differenzdruck hinaus etwas geöffnet ist.
• 2) Andererseits wird in dem Fall, dass der Ansaugdruck Ps kleiner als der voreingestellte Druckwert Pset ist, der Schenkelabschnitt 54 mit der Unterseite 64 des Korpus 5 so in Berührung gebracht, dass er auf die Unterseite 64 drückt, wie dies in 4 und 5 dargestellt ist. 4 zeigt dabei einen Zustand in einer Übergangsperiode, in welcher der Ansaugdruck Ps soviel nied riger wird als der voreingestellte Druckwert Pset, dass er den Zustand gemäß 5 erreicht. Wenn außerdem gemäß der Darstellung in 5 der Schenkelabschnitt 54 den Korpus 5 verschiebt, wird dessen Reaktionskraft über die Membran 52, die Scheibe 63, die Feder 53 und das zweite Gehäuse 57 auf die Welle 20 übertragen und wird die Kraft in der Richtung, in der sich die Kraft des Elektromagneten Fs verringert, angelegt. Dementsprechend wird das Ventilelement 18 in Ventilöffnungsrichtung betätigt, wie dies dargestellt ist, während sich der Kurbelgehäusedruck Pc erhöht und die Förderkapazität des Verdichters verringert wird. Infolgedessen steigt der Ansaugdruck Ps. Mit anderen Worten dient das Steuerventil 1 auch als so genanntes Ps-Ventil, welches den Ansaugdruck Ps auf dem voreingestellten Druckwert Pset hält. Wie der obigen Beziehung (2) zu entnehmen ist, kann das Steuerventil 1 den voreingestellten Druckwert Pset dadurch verändern, dass der Wert des dem Elektromagneten 3 zugeführten elektrischen Stroms so verändert wird, dass die Kraft des Elektromagneten Fs geregelt wird.

In other words:

• 1) In the case that the suction pressure Ps is greater than the set pressure Pset, the leg portion is 54 from the bottom 64 of the body 5 lifted off, like this in 2 and 3 is shown. Accordingly, as shown in the above relationship (1), the control valve serves 1 as a so-called Pd-Ps valve, which keeps the differential pressure (Pd-Ps) at the preset value for the differential pressure. Since the resultant force F2 of the springs is set in the above relationship (1), it is possible to change the preset value of the differential pressure by changing the value of the solenoid 3 supplied electric current is changed so that the force Fs of the electromagnet is controlled. 3 FIG. 12 illustrates a state in which the valve portion is slightly opened due to the increase of the differential pressure (Pd-Ps) beyond the preset differential pressure.
• 2) On the other hand, in the case that the suction pressure Ps is smaller than the preset pressure value Pset, the leg portion 54 with the bottom 64 of the body 5 so touched that he is on the bottom 64 expresses how this is in 4 and 5 is shown. 4 shows a state in a transitional period in which the suction pressure Ps is so much nied riger than the preset pressure value Pset, that he the state according to 5 reached. If, in addition, as shown in 5 the leg section 54 the body 5 shifts its reaction force across the membrane 52 , the disc 63 , the feather 53 and the second housing 57 on the wave 20 and the force is applied in the direction in which the force of the electromagnet Fs decreases. Accordingly, the valve element becomes 18 operated in the valve opening direction, as shown, while the crankcase pressure Pc increases and the delivery capacity of the compressor is reduced. As a result, the suction pressure Ps increases. In other words, the control valve serves 1 also as a so-called Ps valve, which keeps the suction pressure Ps at the preset pressure value Pset. As can be seen from the above relationship (2), the control valve 1 Change the preset pressure value Pset by changing the value of the electromagnet 3 supplied electric current is changed so that the force of the electromagnet Fs is controlled.

6 FIG. 14 is a view for explaining and showing a state of changes in the discharge pressure and the suction pressure from the time when the compressor is started. In the Drawing indicates a horizontal axis the lapse of time t from the start time, while a vertical axis indicates the discharge pressure Pd and the suction pressure Ps. Further, a change of the discharge pressure Pd is indicated by a dotted line, while a solid line indicates a change of the suction pressure Ps.

In the case that the electromagnet 3 of the control valve 1 no power is supplied, so in the case of a mode of operation with minimum capacity, in which the function of the compressor substantially stops, there is a state in which the differential pressure (Pd - Ps) is approximately zero. At this time, as shown, the discharge pressure Pd and the suction pressure Ps reach approximately the same pressure value.

In addition, if the electromagnet 3 Power is supplied and the compressor is started, a control is performed in the form that the differential pressure (Pd - Ps) is higher in small steps and thus comes close to the preset differential pressure. At this time, the function of the pressure detecting part becomes 6 the force is applied in the direction in which the force of the electromagnet Fs decreases as the differential pressure (Pd-Ps) becomes higher and the suction pressure Ps becomes lower than the preset pressure value Pset so as to increase the cooling capacity. In other words, the control valve works 1 automatically in such a manner that the suction pressure Ps is equal to or higher than the preset pressure value Pset. Accordingly, the suction pressure Ps is not largely reduced even when the suction pressure Ps is decreased, as indicated by the dotted line in the drawing, but is clearly maintained at the preset pressure value Pset.

As already stated, at a normal time when the suction pressure Ps is higher than the preset pressure value Pset, the control valve is used 1 as a Pd-Ps valve which keeps the differential pressure (Pd-Ps) at the preset differential value. When the suction pressure Ps becomes lower than the preset pressure value Pset, the control valve is used 1 as a valve for detecting the Ps value, which keeps the suction pressure Ps at the preset pressure value Pset. In other words, the control valve is used 1 basically, on the one hand as a Pd-Ps valve, which controls the differential pressure (Pd - Ps), and on the other hand as a valve for detecting the Ps value, when the suction pressure Ps drops too much, whereby excessive cooling is prevented.

When next the operation of the entire control valve is described.

At the in 1 illustrated control valve 1 The spring force is in the valve opening direction, that of the spring 26 and the spring 46 is set to a value which is greater than the value of the spring load in the valve closing direction, by the spring 47 is produced. Accordingly, in the case that the electromagnet 3 no power is supplied, the valve element 18 from the delivery pressure Pd always from the valve seat 16 kept lifted while the valve section is kept in the fully open state. At this time, the high pressure and the discharge chamber of the compressor flows through the passage 11 supplied coolant, which is below the discharge pressure Pd, through the valve portion in the fully open state and flows from the passage 13 to the crankcase. Accordingly, since the crankcase pressure Pc reaches the pressure value close to the discharge pressure Pd, the compressor operates in a minimum capacity mode.

On the other hand, in the case where the air conditioner for the automobile is turned on or the cooling load has the maximum value, the value of the solenoid goes 3 supplied current to maximum value while the plunger coil 33 through the highest possible suction force into the core 32 is sucked. At this time, the operating rod 17 including the valve element 18 , the pressure sensing part 6 , the wave 20 and the plunger coil 33 , operated integrally in the valve closing direction and sets the valve element 18 on the valve seat 16 on. Since the crankcase pressure Pc is reduced by the function for closing the valve, the compression works with the largest possible capacity.

If in this case the value of the electromagnet 3 supplied current is set to a predetermined value, the operating rod 17 including the valve element 18 , the pressure sensing part 6 , the wave 20 and the plunger coil 33 operated integrally. At this time, the valve element stops 18 in a valve lift position where the spring load of the spring 26 which the pressure sensing part 6 in the valve opening direction, the spring load of the spring 46 which the plunger coil 33 in the valve opening direction, the load of the electromagnet 3 which is the plunger coil 33 in the valve closing direction, which is generated by the delivery pressure Pd, the valve element 18 takes in the valve opening direction, and the force generated by the suction pressure Ps, the valve element 18 takes over in the valve closing direction, are balanced.

In this balanced state, when the rotational speed of the compressor increases and the rotational speed of the engine and the discharge capacity increase As a result, the differential pressure (Pd-Ps) becomes large, the force in the valve opening direction to the valve element becomes large 18 created and becomes the valve element 18 further increased so as to increase the flow rate of the coolant that circulates from the outlet chamber to the crankcase. Accordingly, the crankcase pressure Pc increases, and the compressor is operated in the direction in which the delivery amount is decreased and controlled so that the differential pressure (Pd-Ps) moves toward the preset differential pressure. In the case where the revolution speed of the engine is reduced, the operation is reversed, and the compressor is controlled so as to develop the differential pressure (Pd-Ps) to the preset differential pressure.

In addition, in the course of operation of the refrigeration cycle based on the operation of the compressor in the manner described above, the suction pressure Ps becomes lower than the preset pressure value Pset, the leg portion is set 54 of the element 55 for transmitting the reaction force which the pressure sensing element 6 forms, on the corpus 5 on and becomes the reaction force to the shaft 20 applied in the direction in which the force of the electromagnet decreases. The force in the valve closing direction, which is connected to the valve element 18 is applied, is reduced accordingly and thereby the valve section opens. As a result, the crankcase pressure Pc increases so that the flow rate is reduced. As a result, the suction pressure Ps is maintained at the preset pressure value Pset, and an excessive cooling effect is prevented.

As already described above, in the control valve 1 According to the embodiment discussed here, the suction pressure Ps is monitored while the initial control of the capacity is carried out to keep the difference value (Pd-Ps) at the preset differential pressure value. When the suction pressure Ps becomes lower than the preset pressure value Pset, the pressure detection part generates 6 the force in the direction in which the force of the electromagnet is reduced. Since the suction pressure Ps is approximately proportional to the outlet temperature of the evaporator in the refrigeration cycle, the low suction pressure Ps provides an indication of the low outlet temperature of the evaporator. As already explained, the discharge capacity of the compressor is reduced by lowering the force of the solenoid so that it becomes easy to open the valve portion when the suction pressure Ps becomes lower than the preset pressure value Pset, whereby it is possible to over-pressurize to prevent strong cooling.

Since the capacity control from the pressure sensing part 6 is carried out automatically, which the suction pressure Ps of the pressure chamber 25 detected, it is possible to prevent the freezing or similar phenomena of the evaporator. In addition, because the pressure sensing part 6 inside the body 6 is provided, it is possible to achieve that the control valve has the control characteristic of both the Pd-Ps valve and the PS detection valve in the above-described manner with a simple structure.

Second embodiment

Next, a second embodiment of the present invention will be described. A control valve according to the embodiment discussed here differs from the first embodiment in the point that the valve element is constructed of a part of the housing of the pressure sensing part, that is, in the aspect that the pressure sensing part works by detecting the crankcase pressure Pc and similar parameters, however the control valve has much in common with the A sections and parts shown in the first embodiment. Accordingly, the same constituents as those in the first embodiment are given the same reference numerals, while the description of these constituents is not repeated here. 7 shows a cross-sectional view showing the structure of the control valve according to the second embodiment. 8th is a partially enlarged cross-sectional view, which is an upper half section 7 equivalent.

As shown in 7 is a control valve 201 for an adjustable compressor constructed as a so-called Pd-Pc valve, which controls the flow rate of a refrigerant, which is introduced from a discharge chamber into a crankcase in such a way that a differential pressure (Pd - Pc) between a delivery pressure Pd and a crankcase pressure Pc of the compressor (not shown) is maintained at a preset differential pressure value.

The control valve 201 is by integral assembly of a valve main body 202 constructed, which opens and closes a coolant passage for introducing a part of a conveyed coolant into the crankcase, wherein an electromagnet 3 the degree of opening of a valve portion of the valve main body 202 in the way that regulates the flow rate of a connection part 4 is controlled in the crankcase coolant introduced.

A corpus 205 of the main valve body 202 is not provided with a passage through which the suction pressure Ps is introduced, and is made more compact than the body 5 according to the first embodiment. A passage to which the delivery pressure Pd is applied is in an upper portion of the body 205 provided during the passage 11 with a passage 13 is brought into fluid communication, in a lateral portion of the body 205 is provided in an inner portion. A coolant line that provides a flow connection from the passage 11 to the passage 13 makes a valve opening 15 while an end surface in the side thereof to the crankcase has a valve seat 16 forms. The passage 13 is in flow communication with an opening 24 placed in the middle of a lower end of the body 205 is provided and has a predetermined depth.

An interior free space that the body 205 and the electromagnet 3 enclose and in which the opening 24 is positioned, forms a pressure chamber 225 into which the crankcase pressure Pc is introduced. The crankcase pressure Pc becomes an inside portion of the solenoid 3 initiated. A pressure sensing part 206 serving as a pressure detecting portion, which is operated with detection of the crankcase pressure Pc, is in the pressure chamber 225 arranged. Furthermore, a valve element 218 provided, which extends from the side of the crankcase to the valve seat 16 towards and away from it, and from a central portion of an upper end of the pressure detecting part 206 is constructed. A feather 226 which the pressure sensing part 206 in the valve opening direction, is between the pressure sensing part 206 and the body 205 used.

As shown in 8th has the pressure sensing part 206 in approximately the same structure as the pressure sensing part 6 according to the first embodiment, however, is a flat portion in a central region of the upper end of a first housing 256 from which the case 251 is constructed, integrally a valve element 218 built, which is the valve seat 16 towards and away from it.

If at the control valve 201 the crankcase pressure Pc becomes smaller than the preset pressure value due to the decrease of the suction pressure Ps, become three leg portions 54 of the element 55 for transmitting the reaction force to the bottom 64 of the body 205 so touched that they press on this. The reaction force with which the leg sections 54 on the body 205 press, over the membrane 52 , the disc 63 , the feather 53 and the second housing 57 on the wave 20 while the force is applied in the direction in which the force of the electromagnet Fs is reduced. Accordingly, the valve element becomes 18 operated in the valve opening direction, increases the crankcase pressure Pc and reduces the delivery capacity of the compressor. As a result, the suction pressure Ps increases. In this case, the pre-set pressure is basically previously determined by the spring force of the spring 53 regulated and set as a pressure value, which is capable of preventing the freezing of the evaporator based on a relationship between the temperature inside the evaporator and the suction pressure Ps and a relationship between the suction pressure Ps and the crankcase pressure Pc.

According to the control valve 201 According to the embodiment discussed herein, the crankcase pressure Pc is monitored while the initial capacity control is performed to maintain the differential pressure (Pd-Pc) between the discharge pressure value Pd and the value of the crankcase pressure at the preset differential pressure value. When the crankcase pressure Pc becomes lower than the preset pressure value, the pressure detecting part generates 206 the force in the direction in which the force of the electromagnet decreases. Since the suction pressure Ps is lowered as described above, the discharge capacity of the compressor is reduced by decreasing the force of the solenoid to easily open the valve portion when the crankcase pressure Pc becomes lower than the preset pressure value Pset it becomes possible to prevent excessive cooling.

Since the pressure sensing part 206 , which the crankcase pressure Pc of the pressure chamber 225 detected, automatically performs the capacity control, it is possible to effectively prevent the freezing or similar phenomena on the evaporator. In addition, because the pressure sensing part 206 inside the body 205 is provided, it can be achieved that the control valve has the control characteristic of both the Pd-Pc valve and the Pc detection valve in the manner described above with a simple structure.

Third embodiment

Next, a third embodiment of the present invention will be described. In this case, a control valve according to the embodiment described here differs largely from the first embodiment in the point that the detection part is provided in an end portion instead of in the inner portion of the body, while sharing a plurality of parts with the construction shown in the first embodiment. Accordingly, the components which are approximately the same as those of the first embodiment are given the same reference numerals ordered and their description is not repeated here. 9 shows a cross-sectional view showing the structure of the control valve according to the third embodiment. 10 shows a partially enlarged cross-sectional view, which is an upper half part 9 equivalent.

As shown in 9 is a control valve 301 for an adjustable compressor constructed as a Pd-Ps valve which operates to maintain a differential pressure (Pd-Ps) of the compressor (not shown) at a preset value for the differential pressure.

At the control valve 301 is a side section of a carcass 305 of the main valve body 302 with a passage 11 provided, which is in fluid communication with the outlet chamber from an upper side, while a passage 13 is in flow communication with the crankcase, and a passage 22 is in flow communication with the suction chamber. The passage 22 is with an opening 24 connected, which is provided in the middle of a lower end of the body and having a predetermined depth. An interior, of the corpus 305 and the electromagnet 3 is enclosed and its opening 24 is positioned there forms a pressure chamber 325 to which the suction pressure Ps is supplied.

A cylindrical element 314 , which forms a valve seat, is fitted in a coolant line under pressure, which the passage 11 with the passage 13 links; In this case, from a lower half portion of the inside line, a valve opening 15 formed while an inner peripheral edge on the side of the crankcase a valve seat 16 forms. The valve seat forming element 314 is with a leadership hole 315 provided in the axial direction by the element 314 to form a valve seat, while sliding a transmission rod 316 inserted therein, which will be described in detail below.

The body 305 is with a pressure sensing part 306 provided in such a way that an opening area is sealed at the upper end. The pressure sensing part 306 is the pressure sensing part 306 similar to the first embodiment and is on the body 305 fastened in a position in which the similar construction is reversed. Furthermore, in the body 305 a flow path 317 formed extending in a vertical direction at a position which is slightly different from the valve seat forming element 314 is removed and the opening area at the top of the carcass 305 with the pressure chamber 325 combines.

As shown in 10 is the pressure sensing part 306 constructed so that an inner portion of a first housing 356 , the one housing 351 forms for, in flow communication with the pressure chamber 325 over the flow path 317 brought and the suction pressure Ps is introduced therein. A disk 355 and a transmission rod 316 are after each other at the bottom of the membrane 52 welded. In this case, make the disc 355 and the transmission rod 316 an element for transmitting a decreasing force.

The transmission rod 316 is sliding into the guide hole 315 introduced and its lower end extends to a portion near the upper end of the shaft 20 , Furthermore, in a central region in the axial direction of the transmission rod 316 a locking section 321 provided, which projects in the radial direction, wherein the transmission rod 316 on an inner wall of the valve seat forming member 314 is secured, whereby an upper dead center is defined and a movement is controlled in the axial direction. A connection hole 323 which the passage 11 with the valve opening 15 connects, is in a lateral portion of the valve seat forming member 314 educated.

On the other hand, a valve element 318 integral from the upper end portion of the shaft 20 educated. The wave 20 is sliding on a guide hole 324 stored between the passage 13 and the passage 22 in the corpus 305 is trained; the valve element 318 is arranged so that it is from the side of the crankcase to the valve seat 16 can be brought and moved away from it. At the time the valve opens, when the valve member 318 from the valve seat 16 is lifted off, the high pressure coolant coming out of the passage 11 over the connection hole 323 the valve opening 15 was fed, outward to the side of the passage 13 passed through a coolant line between the valve port 15 and the transmission rod 316 is trained.

If at the control valve 301 the suction pressure Ps becomes lower than the preset pressure value, the diaphragm becomes 52 under the action of the tension of the spring 53 shifts down and gets the power over the disc 355 and the transmission rod 316 on the wave 20 transfer. Accordingly, the force is applied in the direction in which the force of the electromagnet Fs becomes lower, and thus the valve element operates 318 in the valve opening direction. As a result, the crankcase pressure Pc increases, the discharge capacity of the compressor decreases, and the suction pressure Ps increases.

At the control valve 301 According to the embodiment described here, the suction pressure Ps is monitored while the control of the anfängli Chen capacity runs to keep the differential pressure (Pd - Ps) to the preset value of the differential pressure. When the suction pressure Ps becomes lower than the preset pressure, the pressure detection part generates 306 the force in the direction in which the force of the electromagnet decreases. The discharge capacity of the compressor is reduced by applying the force against the force of the solenoid to make it easy to open the valve portion when the suction pressure Ps becomes lower than the preset pressure value, as described above, whereby it is possible to to prevent excessive cooling.

Since the pressure sensing part 306 that the suction pressure Ps in the pressure chamber 325 detects that performs capacity control automatically, it is possible to effectively prevent the freezing or similar phenomena on the evaporator. In addition, because the pressure sensing part 306 at one end of the body 305 is provided, it can be achieved that the control valve has the control characteristic of both the Pd-Ps valve and the valve for detecting the Ps value in the manner described in a simple structure.

Fourth embodiment

Next, a fourth embodiment of the present invention will be described. In this case, a control valve according to the embodiment described here differs largely from the first embodiment in the point that the valve seat is formed by a movable valve seat, while having a plurality of parts in common with the construction shown in the first embodiment. Accordingly, the components which are approximately the same as those of the first embodiment are assigned the same reference numerals and the description thereof is not repeated here. 11 shows a cross-sectional view showing the structure of the control valve according to the fourth embodiment. 10 shows a partially enlarged cross-sectional view, which is an upper half part 11 equivalent.

As shown in 11 is a control valve 401 for an adjustable compressor constructed as a Pd-Ps valve which operates to maintain a differential pressure (Pd-Ps) of the compressor (not shown) at a preset value for the differential pressure.

In a valve main body 402 of the control valve 401 are the passage openings 11 . 13 and 22 formed in the same arrangement as in the first embodiment. In a corpus 405 is a cylindrical moving element 414 for forming a valve seat through a through opening 411 used in the axial direction, which the passage 11 with the passage 13 connects, while an internal line a valve opening 15 forms and an inner peripheral edge in an end face on the side of the crankcase a valve seat 16 forms.

On the one hand there is the passage 22 with an opening 24 in the middle of the lower end of the body 405 in fluid communication, and on the other hand is a pressure chamber 25 formed, to which the suction pressure Ps is supplied. In the pressure chamber 25 is a pressure sensing part 406 serving as a pressure detecting section, which operates under detection of the suction pressure Ps. Furthermore, between the pressure sensing part 406 and the movable element 414 to form a valve seat an actuating rod 417 arranged. An upper end surface of the operating rod 417 is slightly larger than the valve opening 15 ; the upper end portion forms a valve element 418 , The valve element 418 is in the axial direction together with the actuating rod 417 operated and settles on the valve seat 16 move to and from this, so the valve opening 15 to open and close.

As shown in 12 is the moving element 414 provided for forming a valve seat in an upper end portion, wherein a flange portion 415 protrudes outward in the radial direction. On the other hand, in an opening area at the upper end of the body 405 an annular element 416 fitted to receive a spring under pressure. A feather 419 that the movable member forming the valve seat 414 is biased down, is between the spring receiving part 416 and the flange portion 415 used; however, since the flange section 415 at an area near an opening area at the upper end of the through hole 411 is secured, here is a bottom dead center of the movable element 414 defined to form a valve seat and a movement in the axial direction is regulated.

The pressure sensing part 406 has a disc 421 on, attached to an area in one side of the membrane 52 welded to the open space S2, as well as an element 423 for transmitting a reaction force to the disc 421 is appropriate. The element 423 for transmitting a reaction force has three leg portions in the bottom and the top of a cylindrical main body 424 on (of which in the drawing only one in the top and the bottom is shown). The main body 424 is in axial Direction sliding into a guide hole 425 introduced the passage 13 with the passage 22 combines. The leg sections 426 extending from the main body 424 extend downwards, each through three through holes 61 guided in the first case 56 are provided, and are from the bottom of the disk 421 supported. On the other hand, leg sections 427 extending from the main body 424 extend upward, so arranged as to be a bottom of the movable element 414 to face a valve seat and by an upward displacement of the element 423 for transmitting a reaction force to the underside of the movable member 414 can be freely set to form a valve seat and released from this

If at the control valve 401 the suction pressure Ps becomes lower than the preset pressure value, the diaphragm becomes 52 shifted up and come the upper leg sections 427 of the element 423 for transmitting a reaction force to the bottom of the movable member 414 to form a valve seat in contact so that they press on this. As a result, the valve member forming a movable member 414 shifted slightly upwards. On the other hand, the reaction force with which the leg sections 427 on the body 405 Press, over the membrane 52 , the disc 63 , the feather 53 and the second housing 57 on the wave 20 transmitted while the force in the direction in which the force of the electromagnet Fs is applied. Accordingly, the valve element becomes 418 relatively controlled in the valve opening direction and thus the Kurbelgehäu sedruck Pc increases while the delivery capacity of the compressor is reduced. As a result, the suction pressure Ps increases.

At the control valve 401 According to the embodiment described here, the suction pressure Ps is monitored while the control of the initial capacity is performed to keep the differential pressure (Pd-Ps) at the preset value of the differential pressure. When the suction pressure Ps becomes lower than the preset pressure, the pressure detecting part generates 406 the force in the direction in which the force of the electromagnet decreases. The discharge capacity of the compressor is reduced by decreasing the force of the solenoid to make it easy to open the valve portion when the suction pressure Ps becomes lower than the preset pressure value as described above, whereby it is possible to suppress the excessively high Prevent cooling.

Since the pressure sensing part 406 that the suction pressure Ps in the pressure chamber 25 detects that performs capacity control automatically, it is possible to effectively prevent the freezing or similar phenomena on the evaporator. In addition, because the pressure sensing part 406 at one end of the body 405 is provided, it can be achieved that the control valve has the control characteristic of both the Pd-Ps valve and the valve for detecting the Ps value in the manner described in a simple structure.

Fifth embodiment

Next, a fifth embodiment of the present invention will be described. In this case, a control valve according to the embodiment described here differs largely from the first embodiment in the point that the body is simply constructed of a member which is obtained by press-forming stainless steel or the like, but while a plurality of parts with that in the first embodiment has in common construction shown. Accordingly, the components which are approximately the same as those of the first embodiment already described, the same reference numerals assigned and their description is not repeated here. 13 shows a cross-sectional view showing the construction of the control valve according to the fifth embodiment.

This control valve 501 for an adjustable compressor is constructed as a Pd-Ps valve, which controls the flow rate of a discharged from a feed chamber in a crankcase coolant, wherein a differential pressure (Pd - Ps) of the compressor 500 is held at a preset value for the differential pressure.

The control valve 501 is by integrally assembling a valve main body 502 which opens and closes a coolant line for introducing a part of a conveyed coolant into the crankcase, and an electromagnet 503 constructed, which controls a flow rate of the introduced into the crankcase coolant, characterized in that the opening degree of a valve portion of the valve main body 502 is regulated.

The main valve body 502 is with a cylindrical body 505 provided with a closed end, which is obtained by compression molding, and with a in the body 505 provided valve mechanism, a pressure sensing part 506 , which controls the valve mechanism, and similar elements.

A cylindrical stop part 511 with closed end, which was made by compression molding, is in the lower half section inside the body 505 fitted under pressure in a position in which a lower portion thereof is attached to an upper side, while a cylindrical guide member 512 under pressure in egg NEN middle section is fitted in a top. It is also in an opening area of the carcass 505 at the top of a cylindrical element 513 with closed end to form a valve seat fitted under pressure.

In the middle of a lower section of the element 513 to form a valve seat is a valve opening 507 is provided, which connects a delivery chamber of the compressor with a crankcase, and forms an inner peripheral edge of an end face on the side of the crankcase a valve seat 508 , In addition, a gap forms between a guide part 512 inside the body 505 and the element 513 to form a valve seat the Kühlmitteilleitung, while in its lateral portion of the body 505 the passage 13 is provided, which corresponds to the coolant line. The from the passage 11 supplied delivery pressure Pd is reduced by the passage through the valve portion and generates the controlled crankcase pressure Pc. The crankcase pressure Pc is discharged to the outside through the passage 13 led to the side of the crankcase out.

In addition, an end portion of an elongated actuating rod forms 517 a valve element 518 , which is arranged so that it can freely approach this and move away from it so that it from the side of the crankcase from the valve seat 508 opposite. The operating rod 517 is sliding at a guide opening 519 supported in the middle of the guide part 512 is provided.

In addition, at corresponding positions on respective lateral portions of the body 505 and the stopper part 511 a passage 22 formed, which is in flow communication with the suction chamber of the compressor and takes over the suction pressure Ps. The passage 22 is in fluid communication with an internal free space which is a lower portion of the guide member 512 of the body 505 forms. An opening section 521 is in the middle at a lower end of the body 505 provided and places between the inner space and an inner portion of the electromagnet 503 a flow connection ago. The one from the corpus 505 and the electromagnet 503 enclosed interior space forms a pressure chamber 525 into which the suction pressure Ps is introduced. The suction pressure Ps also becomes the inner portion of the electromagnet 503 fed. A pressure sensing part 506 serving as a pressure detecting section which detects the suction pressure Ps for its operation is in the pressure chamber 525 arranged; the detailed description can be found in the following text.

On the other hand, the electromagnet 503 with a housing serving as a yoke 531 , one inside the case 531 attached core 532 , a plunger 533 which is arranged so that it is in the axial direction of the core 532 opposite, and an electromagnetic coil 534 provided that builds a magnetic circuit from an outer part when power is supplied. The main valve body 502 and the electromagnet 503 are coupled by having a lower end portion of the body 505 and an upper end portion of the housing 531 face each other and a connecting portion by caulking an upper end portion of the core 531 is attached.

The core 532 is with an insertion hole 535 provided that is guided by its center in the axial direction, as well as with a shaft 520 for transmitting the force of the electromagnet to the valve element inserted therein 518 , Because between the upper end portion of the core 532 and the wave 520 a given clearance is present, the inside of the pressure chamber 525 prevailing suction pressure Ps on the clearance in the inner portion of the electromagnet 503 directed.

Furthermore, a sleeve 536 with closed lower end from the outside into the core 532 used. Inside the sleeve 536 with closed end is the plunger 533 arranged so that it is in the axial direction in a bottom of the core 532 is movable forward and backward. The sleeve 536 with the end closed shrunk into a lower end portion and pivoted over the shrunken portion the lower end portion of the shaft 520 sliding.

The plunger 533 is stepped cylindrically shaped and under pressure in the lower half section of the shaft 520 fitted. A feather 537 which the plunger 533 in one direction, in which he strays from the core 532 moving away is between the core 532 and the plunger 533 used. It is also between the plunger 533 and the sleeve 536 with closed end a spring 538 used, which the plunger 533 in one direction, in which he attaches himself to the core 532 approaches.

An opening area at the bottom of the housing 531 is with a handle 540 provided so that the inner area of the electromagnet 503 is sealed against a bottom. The handle 540 also serves as a connecting section, one end of one with the coil 534 of the electromagnet connected connector releases.

The control valve constructed as described above 501 is inside the given Kühlmitteilleitung the compressor 500 over a mounting plate 545 attached.

The structure and mode of operation around the detection part will now be described below. 14 and 15 FIG. 12 are views for explaining the operation of the control valve, which correspond to the partially enlarged cross-sectional view, which is an upper half portion 13 equivalent. 14 shows a state in which during the control of the differential pressure (Pd - Ps), the suction pressure Ps is higher than a preset pressure. 15 on the other hand, shows a state in which, during the control of the differential pressure (Pd-Ps), the suction pressure Ps is higher than the preset pressure value.

As shown in 14 has the pressure sensing part 506 in approximately the same structure as the pressure sensing part 6 in the first embodiment; but it differs slightly in the construction of a first housing 556 which the housing 551 forms. In other words, by press forming in the middle of a lower portion on the opposite side of the membrane 52 in the first case 556 a concave rod coupling area 557 formed while loosely a lower end portion of the actuating rod 517 is mounted. Furthermore, at three positions, which are the actuating rod 517 in the first housing 556 surrounded, formed through holes, in which three leg sections 54 of the element 555 are used to transmit the reaction force so that they are to the side of the valve element 518 protrude.

The element 555 for transmitting the reaction force is about the same size as the disc 63 educated. The leg section 54 settles on one of the shaft 520 attach in the body facing side and release it again, ie to or from a lower portion of the stop member 511 in correspondence with the operation of the pressure detecting part 506 ,

On the other hand, between a lower end portion of the operating rod 517 and the leadership part 512 a conically shaped spring 560 provided, which serves as a clamping element, which the valve element 518 clamped in the valve opening direction.

In the structure described above, when the suction pressure Ps becomes higher than the preset pressure, the leg portion is 54 from the stopper part 511 removed, like this in 14 can be seen. Accordingly, the control valve is used 501 as a so-called Pd-Ps valve, which maintains the differential pressure (Pd-Ps) at a preset value for the differential pressure. The drawing shows a state in which the valve portion is slightly opened because the differential pressure (Pd-Ps) becomes higher than the preset differential pressure.

On the other hand, when the suction pressure Ps is lower than the preset pressure value, the leg portion becomes 54 with the stopper part 511 so touched that he touched the stopper 511 expresses how this is in 15 you can see. The reaction force with which the leg section 54 on the stopper part 511 presses, over the membrane 52 , the disc 63 , the feather 53 and the second housing 57 on the wave 520 while the force is applied in the direction in which the force of the electromagnet Fs becomes lower. Accordingly, the valve element becomes 518 operated in the valve opening direction, as the drawing shows, the crankcase pressure Pc increases and reduces the delivery capacity of the compressor. As a result, the suction pressure Ps increases.

At the control valve 501 According to the embodiment described here, the suction pressure Ps is monitored while the control of the initial capacity is performed to keep the differential pressure (Pd-Ps) at the preset value of the differential pressure. When the suction pressure Ps becomes lower than the preset pressure, the pressure detecting part generates 506 the force in the direction in which the force of the electromagnet decreases. The discharge capacity of the compressor is reduced by decreasing the force of the solenoid to make it easy to open the valve portion when, as described above, the suction pressure Ps becomes lower than the preset pressure value, thereby making it possible to excessively high Prevent cooling.

Since the pressure sensing part 506 that the suction pressure Ps in the pressure chamber 525 detects that performs capacity control automatically, it is possible to effectively prevent the freezing or similar phenomena on the evaporator. In addition, because the pressure sensing part 506 at one end of the body 505 is provided, it can be achieved that the control valve has the control characteristic of both the Pd-Ps valve and the valve for detecting the Ps value in the described manner with a simple structure.

Sixth embodiment

Next, a sixth embodiment of the present invention will be described. Here, a control valve according to the embodiment described here differs largely from the first embodiment in the point that the control valve is constructed as a control valve for flow control, which controls the flow rate of the conveyed coolant to a constant value, while a plurality of parts with the in the first embodiment shown construction has in common. Accordingly, the components that are approximately equal to those from the First Embodiment, the same reference numerals are assigned and their description is not repeated here. 16 shows a cross-sectional view showing the structure of the control valve according to the sixth embodiment. 17 shows a partially enlarged cross-sectional view, which is an upper half part 16 equivalent.

As 16 shows is a control valve 601 for an adjustable compressor constructed by integrally forming a valve main body 602 and opening and closing a refrigerant pipe for introducing a part of the conveyed coolant into the crankcase, and a solenoid valve 3 are integrally mounted, which controls a flow rate of the introduced into the crankcase coolant by the degree of opening of a valve portion of the valve main body 602 is regulated.

Here is a side section of a carcass 605 of the main valve body 602 with a passage 611 provided which is in flow communication with an outlet of the compressor so that it assumes a discharge pressure Pdl, as well as with a passage 612 which is in flow communication with a delivery chamber for receiving a delivery pressure Pdh, and with a passage 613 which is in fluid communication with a crankcase so as to take in a crankcase pressure Pc from an upper side. In this case, since a pressure-reducing means such as a shutter or the like is provided between the delivery chamber and the outlet of the compressor, the delivery pressure Pdh reaches a higher pressure than the delivery pressure Pdl under normal control operation.

Furthermore, a bellows 620 provided, which serves as a pressure detecting device and expands and contracts in the axial direction and also an opening portion at the upper end of the body 605 seals. The bellows 620 is constructed in such a way that it is able to be integral with the shaft 20 over a transmission rod 630 and a pressure sensing part 640 to work.

The bellows 620 has an interior region of an expansible main body 621 a pressure chamber 622 on. An upper end of the main body 621 is at a first stop part 623 fastened, which under pressure in the opening area of the carcass 605 is fitted at the upper end, while the lower end with a second stop member 624 is closed, that the first stop part 623 in the axial direction opposite. The first stop part 623 is with a flow path 625 for introducing the coolant, which is in flow communication with a delivery chamber of the compressor, whereby it is possible, the delivery pressure Pdh of the pressure chamber 622 in an interior section of the main body 621 initiate. On the other hand, an outside of the gallows 620 inside the body 605 as a pressure chamber 626 trained with the passage 611 is in flow communication. Accordingly, the bellows detected 620 a differential pressure (Pdh - Pdl) between the discharge pressure Pdh and the discharge pressure Pdl so as to expand and contract in the axial direction.

Furthermore, in the middle of the bottom of the second stop member 624 a circular groove 627 is provided, which extends along the axial direction at a predetermined depth and in which an upper end portion of the transmission rod 630 is introduced.

As shown in 17 is the transmission rod 630 sliding into a through opening 631 inserted in the middle of the carcass 605 is provided. An upper end portion of the transmission rod 630 is in the pressure chamber 626 arranged so that they touch the bellows 620 is coupled. On the other hand, a lower end portion of the transmission rod 630 arranged in a coolant line, which has a smaller diameter and the passage 612 with the passage 613 brings into fluid communication while it to the pressure sensing part 640 is coupled. The coolant line, which is the flow connection between the passage 612 and the passage 613 makes a valve opening 632 , and an inner peripheral edge of an end face on the side of the crankcase (ie, the side of the passage 613 ) forms a valve seat 16 ,

The pressure sensing part 640 has approximately the same structure as the pressure sensing part 6 in the first embodiment, but here forms an upper end surface of a first housing 642 which is a housing 641 forms, a valve element 618 on the valve seat 16 is movable to and from this. A lower end portion of the transmission rod 630 is loose in a concave section 643 inserted in the middle of an upper end surface of the first housing 642 is provided

If at the control valve 601 the suction pressure Ps is high and the crankcase pressure Pc is higher than the preset pressure value, the leg portion is located 54 in the distance from the bottom 564 of the body 605 , Accordingly, the control valve is used 601 as the control valve for the control of the flow rate, which regulates the flow rate of the conveyed coolant to a constant value, while the pressure sensing part a 640 does not affect the degree of opening of the valve section.

In other words, when the flow rate in the refrigerant flow is increased beyond a preset flow rate, the pressure difference (Pdh-Pdl) between the discharge pressure Pdh and the discharge pressure Pdl becomes large, causing the bellows 620 so long that he stretches the pressure sensing part 640 pushes down and the valve element 618 operated in the valve opening direction. As a result, since the crankcase pressure Pc is raised so as to lower the capacity of the compressor, the discharge capacity changes in the direction of reduction. On the other hand, when the flow rate of the conveyed refrigerant flow is reduced to a value lower than the preset flow rate, the pressure difference (Pdh-Pdl) between the discharge pressure Pdh and the discharge pressure Pdl becomes smaller, causing the bellows to contract. As a result, the pressure sensing part becomes 640 pushed by the force of the solenoid or the like so that it is the valve element 618 operated in valve closing direction. As a result, since the crankcase pressure Pc is lowered to increase the capacity of the compressor, the delivery capacity changes toward an increase. As already stated, the control valve controls 601 in such a manner that the differential pressure (Pdh - Pdl) reaches the preset value for the differential pressure and the flow rate of the delivered coolant becomes constant. In this case, the preset differential pressure can be controlled by that of the electromagnet 3 applied current value is changed.

In addition, when the crankcase pressure Pc becomes lower than the preset pressure value due to the decrease of the suction pressure Ps, three legs become 54 of the element 55 for transmitting a reaction force to the bottom 564 of the body 605 so touched that they press on this. The reaction force with which the leg sections 54 on the body 605 press, over the membrane 52 , the feather 53 and the second housing 57 on the wave 20 transmitted while the force is applied in the direction of reducing the force Fs of the electromagnet. Accordingly, the valve element becomes 618 operated in the valve opening direction, the crankcase pressure Pc is increased and the delivery capacity of the compressor is reduced. As a result, the suction pressure Ps increases.

At the control valve 601 According to the embodiment described here, the crankcase pressure Pc is monitored, while the control of the initial flow rate is performed so that the differential pressure (Pdh - Pdl) is maintained at the preset value of the differential pressure. When the crankcase pressure Pc becomes lower than the preset pressure, the pressure detecting part generates 606 the force in the direction in which the force of the electromagnet decreases. The discharge capacity of the compressor is reduced by decreasing the force of the solenoid to make it easy to open the valve portion when the crankcase pressure Pc becomes lower than the preset pressure value as a result of the decrease in the suction pressure, thereby making it possible is to prevent the excessive cooling.

Since the pressure sensing part 640 that the crankcase pressure Pc in the pressure chamber 25 detects that performs capacity control automatically, it is possible to effectively prevent the freezing or similar phenomena on the evaporator. In addition, because the pressure sensing part 640 in the interior of the carcass 605 is provided, it can be achieved that the control valve has the control characteristic of both the flow rate control valve and the valve for detecting the Pc value in the manner described above in a simple structure.

Seventh embodiment

Next, a seventh embodiment of the present invention will be described. In this case, a control valve according to the embodiment described here is approximately the same as the control valve according to the sixth embodiment, except for the point that the pressure sensing part is formed of a bellows. Accordingly, the components which are approximately the same as those of the sixth embodiment are assigned the same reference numerals and their description is not repeated here. 18 shows a cross-sectional view showing the structure of the control valve according to the seventh embodiment. 19 shows a partially enlarged cross-sectional view, which is an upper half part 18 equivalent.

With a control valve 701 for an adjustable compressor is a pressure sensing part 706 a valve main body 702 with a bellows 711 provided, which serves as a flexible part, and with a housing 712 in which the bellows 711 is housed. The bellows 711 has an element 722 for transmitting a reaction force and a stopper part 723 on, and closes both end portions of a main body 721 expands in the axial direction and contracts in this direction. An inside is the section of the main body 721 is designed as a negative pressure area, and between the element 722 for transmitting a reaction force and the stopper part 723 is a spring 724 used that the main body 721 stretched in the expansion direction. A circular groove 725 that extends along an axial direction and has a predetermined depth is in the center of a sub side of the stop part 723 provided while an upper end portion of the shaft 20 is loosely attached to it.

As 19 shows, forms the housing 712 a cylinder shape with a closed end and takes the bellows 711 in the way on that the stopper part 723 is used under pressure in its lower end portion. A concave section 731 which is loosely attached to a lower end portion of an operating rod 730 is attached, which with respect to the gallows 620 is inserted, is in the middle of an upper end surface of the housing 712 intended. Furthermore, there are through openings 61 formed at three positions, which the actuating rod 730 in a peripheral edge portion of an upper end surface of the housing 712 surround; three leg sections 54 of the element 722 for transmitting a reaction force are respectively inserted thereto so as to protrude upward. In this case, the housing can 712 and the stopper part 723 Overall, be perceived as a housing.

A lower end portion of the operating rod 730 is through the valve opening 632 so led that he to the pressure sensing part 706 is coupled. A valve element 718 that is the valve seat 16 from the side of the crankcase is integral with a lower end portion of the operating rod 730 educated.

In the case that at the control valve 701 the suction pressure Ps is high and the crankcase pressure Pc is higher than the preset pressure value is the leg portion 54 from the bottom surface 64 of the body 705 away. Accordingly, the control valve is used 701 as a flow rate control valve that controls the flow rate of the conveyed coolant to a constant value while the pressure detecting part 706 does not affect the degree of opening of the valve section.

In addition, when the crankcase pressure Pc becomes smaller than the preset pressure value due to the decrease of the suction pressure Ps, three legs become 64 of the element 722 for transmitting a reaction force to the bottom surface 64 of the body 705 so touched that they press on this. The reaction force with which the leg sections 54 on the body 705 press, over the bellows 711 on the wave 20 transmitted while the force in the direction in which the force of the electromagnet Fs decreases, is applied. Accordingly, the valve element becomes 718 operated in the valve opening direction and increases the crankcase pressure Pc, while reducing the delivery capacity of the compressor. As a result, the suction pressure Ps increases.

At the control valve 701 According to the embodiment described here, the crankcase pressure Pc is monitored, while the control of the initial flow rate is performed so that the differential pressure (Pdh - Pdl) is maintained at the preset differential pressure. When the crankcase pressure Pc becomes lower than the preset pressure value, the pressure detecting part generates 706 the force in the direction in which the force of the electromagnet decreases. The discharge capacity of the compressor is reduced by decreasing the force of the solenoid to make it easy to open the valve portion when the crankcase pressure Pc becomes lower than the preset pressure value due to the decrease in the suction pressure Ps, as described above is possible to prevent the excessive cooling.

Since the pressure sensing part 706 that the crankcase pressure Pc in the pressure chamber 25 detects that performs capacity control automatically, it is possible to effectively prevent the freezing or similar phenomena on the evaporator. In addition, because the pressure sensing part 706 inside in the body 705 is provided, it can be achieved that the control valve has the control characteristic of both the flow rate control valve and the valve for detecting the Pc value in the manner described in a simple structure.

Eighth embodiment

Next, an eighth embodiment of the present invention will be described. Here, a control valve according to the embodiment described here has the fifth embodiment in common with the control valve having a body made by press-forming stainless steel or the like, however, in terms of the design of the valve portion, the structure of the pressure sensing part and the like different from it. Accordingly, the same reference numerals are assigned to the individual parts which are approximately the same as those in the fifth embodiment and the description thereof is not repeated here. 20 shows a cross-sectional view showing the structure of the control valve according to the eighth embodiment. 21 shows a partially enlarged cross-sectional view, which is an upper half part 20 equivalent.

As 20 shows is a control valve 801 for an adjustable compressor constructed as a Pd-Ps valve which controls the flow rate of a refrigerant introduced into a crankcase from a delivery chamber so as to maintain a differential pressure (Pd-Ps of the compressor.

The control valve 801 is by integral assembly of a valve main body 802 and opening and closing a coolant line for introducing a part of a conveyed coolant into the crankcase, and an electromagnet 803 controlling the flow rate of the refrigerant introduced into the crankcase, the control being made by controlling the opening degree of a valve portion of the valve main body 802 he follows.

The main valve body 802 is with a cylindrical first body 805 provided, which is formed by machining, as well as with a cylindrical second body 806 with closed end, with a pressure sensing part 807 inside the second body 806 is provided and affects the operation of the valve mechanism and the like. A lower end portion of the first body 805 is with a flange section 808 provided, which extends in the radial direction to the outside, while an upper end portion of the second body 806 at the flange portion 808 is fixed by caulking. A lower Endab section of the second body 806 is about a core 825 by caulking on the housing 531 attached.

In a lateral portion of the first body is a passage 11 provided during a passage 13 is provided in the opening portion at the upper end. An element 810 to form a valve seat, which is formed in a stepped cylindrical shape, is under pressure in an upper half portion of the first body 805 fitted, while an opening area at the lower end to an edge of the element 810 to form a valve seat, a valve seat 811 forms. An internal section of the element 810 to form a valve seat forms a valve opening 812 ; a connection opening 813 makes the connection between the inside and the outside and is provided in a lateral portion. On the other hand, an elongated operating rod 815 in an inner portion of the first body 805 arranged. An upper end portion of the operating rod 815 is sliding on the element 810 stored to form a valve seat, and a lower end portion thereof is provided with a pressure sensing element 807 coupled. Bin valve element 816 is integral in a central region of the actuating rod 815 educated.

In its lateral section of the second body 806 is a passage 22 educated. A cylindrical stop part 817 The closed end, which has been made by press forming, is pressurized into an upper half section inside the second body 806 in a state where a bottom portion is set to a lower side. In the middle of a bottom portion of the abutment part 817 an opening portion is provided into which the pressure sensing part 807 is used. Three leg sections 819 an element mentioned below 818 for transmitting a reaction force constitute the pressure sensing part 807 and are to the stopper part 817 moving towards and away from it.

As 21 shows, becomes a lower half section of the element 810 for forming a valve seat under pressure in the first body 805 used while the outer diameter of an upper half section is reduced. An upper end portion of the operating rod 815 is sliding on the valve seat forming element 810 stored, and between an upper end portion and the valve element 816 is a section 820 formed with a reduced diameter. The valve element 816 is positioned at a step portion of the section 820 is formed with a reduced diameter, wherein it is arranged so that faces in such a way that it from the side of the delivery chamber on the valve seat 811 is movable to and from this. Accordingly, this is the passage 11 introduced coolant outside to the side of the passage 13 through a coolant line and a connection opening 813 passed between the section 820 with reduced diameter and the element 810 is designed to form a valve seat. At this time, the one from the side of the passage 11 Induced delivery pressure Pd thereby reduced, that the coolant flows through a valve portion, the valve element 816 and the valve seat 811 form; it reaches the controlled crankcase pressure Pc and thus passes through the passage 13 led to the side of the crankcase. On the other hand, a lower end portion of the operating rod 815 over the membrane 823 with the pressure sensing part 807 coupled. An annular fastener 824 is at an opening portion at the lower end of the first body 805 fixed by caulking while the diaphragm 823 is attached in such a way that an outer peripheral edge between the first body 805 and the fastener 824 is clamped.

Furthermore, under pressure into an opening area at the upper end of the first body 805 an element made by compression molding 821 fitted for receiving a spring while between the element 821 for receiving a spring and the upper end surface of the actuating rod 815 a feather 822 is inserted, which is the valve element 816 clamped in the valve opening direction.

The pressure sensing part 830 is with a hollow case 830 provided between the actuating rod 815 and the wave 20 used and stored so that it moves in the direction bar, in which the valve section opens and closes; it also has a membrane 831 on which is arranged in such a way that they are an inside of the housing 830 divided into a sealed free space S1 and an open space S2 and serves as a flexible part, and a plate spring 832 which is arranged in the sealed free space S1 and serves as an elastic member, and finally an element 818 for transmitting a reaction force accommodated in the open space S2 and three leg portions 819 that passes through the housing 830 are guided and extend upwards. The open space S2 is between the first carcass 805 and the second body 806 designed so that it communicates with the pressure chamber 25 that with the passage 22 is connected, is in flow communication.

The housing 830 is formed in the form of a container in that a first housing 833 , a second housing 834 and a third case 835 assembled by press-forming stainless steel or the like. In other words, the closed-end first housing becomes 833 and the disk-shaped second housing 834 assembled in such a way that their opening areas face each other and an outer edge region of the membrane 831 clamp, which is formed by a polyimide film in an outer edge region. Between the first case 833 and the second housing 834 is applied to the mounting portion an outer circumferential weld in a state in which the membrane 831 is clamped. An opening area for discharging is in the middle of a lower end of the second housing 834 formed while the sealed free space S1 is formed by the welding work is carried out under a vacuum atmosphere and then a ball part 836 is welded for sealing. A convex plate spring 832 in which a mid-area is slightly to an upper side along the membrane 831 is expanded, is disposed in the sealed free space S1. Accordingly, the membrane 831 in convex form along the plate spring 832 formed in the normal situation. In this case, the ambient air or the like may be filled in the interior of the sealed free space S1.

The first case 833 far a cylindrical section 837 on, extending to the opposite side on the second housing 834 extends, ie to an upper side, while the third housing 835 is inserted on the outside in an upper end portion under pressure. The diameter of a central portion of the third housing 835 is reduced so that this portion protrudes in the form of a protrusion, while being inserted under pressure in a lower end portion of the actuating rod. In other words, the diameter of a lower end portion of the operating rod 815 decreases while a small diameter section passes through the center of the membrane 823 so guided is that he under pressure in the survey part of the third housing 835 is fitted. Because the membrane 823 both on the operating rod 815 as well as the third case 835 is tightly fitted in such a way that it is between the actuating rod 815 and the third housing 835 is clamped, it is possible to prevent leakage of the coolant at the top and bottom of the membrane, so that the airtightness is maintained. Accordingly, the pressure chamber 25 not subjected to the delivery pressure Pd.

Furthermore, to the surface on the side of the membrane 831 to the first case 833 a disk-shaped element 818 welded to transmit a reaction force. At three positions of an outer peripheral portion of the element 818 for transmitting a reaction force are leg sections 819 provided, which to a top (ie to one of the membrane 831 opposite side) and from the through hole 838 of the first housing 833 protrude. The leg sections 819 may be due to the operation of the pressure sensing part 807 at the bottom surface 839 the stop part 817 set and be solved by this again. In addition, under pressure is a cylindrical element 841 with closed end for receiving a spring in a cylindrical portion 837 of the first housing 833 fitted. Furthermore, between the spring receiving element 841 and the element 818 for transmitting a reaction force a spring 843 used, which is the element 818 for transmitting the reaction force in one direction, the load of the diaphragm spring 832 directed against. The feather 843 is for fine adjustment of the load of the diaphragm spring 832 provided, and this is based on the amount of the insertion of the spring receiving part 841 in the cylinder section 837 regulated. The open space S2, which is between the first housing 833 and the third housing 835 is formed, stands over the through hole 838 in flow communication with the pressure chamber 25 into which the suction pressure Ps is introduced. Accordingly, the membrane 831 in the opening and closing direction of the valve portion together with the plate spring 832 deformed by the detection of the suction pressure Ps. When the suction pressure Ps becomes high, the plate spring deforms 832 in such a way that they are opposite to the illustrated state (cf. 22 ) is reversed about a peripheral edge portion serving as a support point, and approximately along an inner wall of the second housing 834 extends. In other words, since the inner wall of the two housing 834 is shaped so that it runs approximately along a shape when the plate spring 832 is reversed and thus deformed, the second housing 834 compact.

As the plate spring 832 shaped so that a center area to one side of the element 807 protrudes to transmit a reaction force, the pressure receiving area is deflected to the central area with respect to the entire size, so that it is possible to keep an area to take on a considerable pressure small. Accordingly, it is possible to have a compact structure of the electromagnet 803 contribute. On the other hand, the size of the membrane 831 is fixed, it is possible to ensure a stroke and a smooth movement of the membrane 831 to ensure.

On the other hand, under pressure is a bearing element 851 Sliding the upper end portion of the shaft 20 supports, in an opening area at the upper end of the core 825 fitted, from which the electromagnet 803 is constructed. An inner diameter of an upper half portion of the bearing part 851 is widened and constructed so that a ball part 836 of the second housing 834 is included in it. An upper end portion of the shaft 20 is with the pressure sensing part 807 over the ball part 836 coupled and constructed so that the force of the electromagnet is transmitted from an underside.

In this case, if the suction pressure Ps is inside the pressure chamber 25 becomes lower than the predetermined and preset pressure value Pset, the diaphragm deforms 831 and the plate spring 832 to the side of the valve element 816 as shown in the drawing, while the leg portion 819 of the element 818 for transmitting the reaction force to the floor surface 839 suppressed. As a result, the attached to the element 818 Reaction force applied across the membrane to transfer the reaction force 831 , the plate spring 832 and the second housing 834 on the wave 20 transmitted while the force in the direction in which the force Fs of the electromagnet decreases, is applied. The preset pressure Pset is previously fundamental by the spring loads of the diaphragm spring 832 and the spring 843 adjusted and set as a pressure value with which the freezing of the evaporator can be prevented according to the relationship between the temperature inside the evaporator and the suction pressure Ps prevent.

In this case, as shown in 20 in the embodiment described here, the plunger 533 in the electromagnet 803 under pressure in the shaft 20 fitted and is the spring shown in the fifth embodiment 538 not between the plunger 533 and the sleeve 536 provided with closed end.

Next, the operation of the pressure detecting element will be described next. 22 to 24 are each views for explaining and illustrating an operation of the control valve and correspond 21 , 22 represents a state in which the differential pressure (Pd-Ps) is slightly higher than the preset differential pressure while the suction pressure Ps is higher than the preset pressure. 23 represents the state in which the differential pressure (Pd-Ps) is higher than the preset differential pressure and the suction pressure Ps is above the preset pressure. 24 represents the state during a transient period in which, during the control of the differential pressure (Pd-Ps), the suction pressure Ps becomes just lower than the preset pressure value. In this case, the already explained shows 21 a state in which, during the control of the differential pressure (Pd-Ps), the suction pressure Ps is lower than the preset pressure value.

In other words, when the suction pressure Ps is higher than the preset pressure, the leg portion is located 819 at a distance from the abutment part 817 like this in 22 you can see. Accordingly, the control valve 801 operated as a so-called Pd-Ps valve, which holds the dif ference pressure (Pd - Ps) at the preset differential pressure value. Also shows 23 a state in which the valve portion opens because the differential pressure (Pd-Ps) becomes higher than the preset differential pressure.

On the other hand, when the suction pressure Ps becomes lower than the preset pressure value, the leg portion becomes 819 with the stopper part 817 so touched that he presses on this as in 24 and 21 is shown. The reaction force with which the leg section 819 on the stopper part 817 presses, over the membrane 831 , the plate spring 832 and the second housing on the shaft 20 while the force is applied in the direction in which the force of the electromagnet Fs becomes lower. Accordingly, as shown, the valve element 816 operated in the valve opening direction, increases the crankcase pressure Pc and reduces the delivery capacity of the compressor. As a result, the suction pressure Ps increases.

At the control valve 801 According to the embodiment described here, the suction pressure Ps is monitored while the control of the initial capacity is performed to keep the differential pressure (Pd-Ps) at the preset value of the differential pressure. When the suction pressure Ps is lower than the preset pressure wild, the pressure detection part generates 807 the power in the Direction in which the force of the electromagnet decreases. The discharge capacity of the compressor is reduced by reducing the force of the solenoid to make it easy to open the valve portion when the suction pressure Ps becomes lower than the preset pressure value as described above, whereby the excessive cooling can be prevented ,

Since the pressure sensing part 807 that the suction pressure Ps in the pressure chamber 25 detects that performs capacity control automatically, it is possible to effectively prevent the freezing or similar phenomena on the evaporator. In addition, because the pressure sensing part 807 in the inner area of the second body 806 is provided, it can be achieved that the control valve has the control characteristic of both the Pd-Ps valve and the valve for detecting the Ps value in the manner described above in a simple structure.

Ninth embodiment

Next, a ninth embodiment of the present invention will be described. In this case, a control valve according to the embodiment described herein has a structure which is obtained by simplifying the control valve according to the eighth embodiment. Accordingly, the components which are approximately the same as those of the eighth embodiment are assigned the same reference numerals, and the description thereof is not repeated here. 25 shows a cross-sectional view showing the structure of the control valve according to the ninth embodiment, and 26 is a partially enlarged cross-sectional view, which is an upper half part 25 equivalent.

With a control valve 901 for an adjustable compressor as shown in FIG 25 is the in 21 shown membrane 823 not between the inlet 11 and the inlet 22 intended. In other words, an actuating rod 915 sliding in a guide hole 921 inserted through a first body 905 is guided in the axial direction. A valve element 916 is integral in the actuating rod 915 educated. Because between the actuating rod 915 and the guide hole 921 a small clearance exists, it is possible to leak the coolant from the passage 11 to the passage 22 to prevent. In addition, since a housing and the like of an element 910 for forming a valve seat and a pressure sensing element 907 are small, receives the control valve 901 over its entire length a compact construction.

As in 26 to see is, in other words, the element 910 designed to form a valve seat in a cylindrical shape with a closed end and made by compression molding of stainless steel, while a circular hole formed in the center of a bottom portion, a valve opening 912 forms. Accordingly, a refrigerant line in the valve opening 912 short, so that too the length of a section 920 with a small diameter on a corresponding actuating rod 915 gets shorter. As a result, the entire length of the actuating Stan ge 915 shorter and gets the first body 905 Overall, a compact design.

In addition, the pressure sensing part is 907 not with the third case 835 and with the spring 843 provided in 21 are shown. In other words, a housing 930 constructed by having a cup-shaped first housing and a second housing 834 be attached. An internal section of the housing 930 is with an element 918 provided for transmitting a reaction force, although three leg sections 919 , but no spring for fine adjustment of the load of the diaphragm spring 832 having. Accordingly, the housing 930 and the pressure sensing part 907 Total length made compact by extension. As a result, the second body points 906 that the pressure sensing part 907 absorbs a total of a compact construction.

Each of the leg sections 919 of the element 918 for transmitting a reaction force extends from the through hole 838 of the first housing 933 out to the outside section and can from a bottom 939 of the first corpus 905 be set off and resolved. The reaction force with which the leg section 919 on the first body 905 presses, over the membrane 831 , the plate spring 832 and the second housing 834 on the wave 20 transmitted while the force in the direction in which the force Fs of the electromagnet becomes lower, is applied.

At the control valve 901 According to the embodiment described here, it is possible to have the same functions and effects as in the control valve 801 to obtain according to the eighth embodiment, while meeting the demand for a compact design.

Tenth embodiment

Next, a tenth embodiment of the present invention will be described. In this case, a control valve according to the embodiment described here differs from the eighth embodiment in the point that the control valve is designed as a flow rate control valve, which regulates the flow rate of the delivered coolant to a constant value; nevertheless, it has a plurality of parts in common with the construction shown in the eighth embodiment. Accordingly, the components which are approximately the same as those of the eighth embodiment are assigned the same reference numerals, and the description thereof is not repeated here. 27 shows a cross-sectional view showing the structure of the control valve according to the tenth embodiment. 28 represents a partially enlarged cross-sectional view, which is an upper half part 27 equivalent.

As 27 shows is a control valve 1001 for an adjustable compressor constructed by having a valve main body 1002 and an electromagnet 1003 be assembled integrally together. The main valve body 1002 is made by having a first body 1004 and a second body 1005 be attached under pressure fit and a first valve section 1007 and a second valve portion 1008 in an internal area. The first valve section 1007 controls the flow rate of a coolant that is supplied from the delivery chamber to the crankcase. On the other hand, the second valve section controls 1008 variably the passage cross-sectional area of a refrigerant line through which a high pressure refrigerant flows from the discharge chamber of the compressor to a refrigerant outlet. On the other hand, a connecting part 1009 and a housing 531 by caulking at the upper end portion of a core 1018 of the electromagnet 1003 attached. Furthermore, a lower end portion of the second body 1005 under pressure in the connecting part 1009 fitted, eliminating the valve main body 1002 and the electromagnet 1003 be joined together.

A pressure sensing part 1010 , which is approximately equal to the pressure sensing part 306 according to the in 9 is third embodiment, and the like, under pressure into an opening area at the upper end of the first body 1004 fitted. In this case, the same structure as the construction of the pressure detecting part 306 also assigned the same reference numerals, and thus this description is not repeated here. A passage 1012 which is in fluid communication with the crankcase so as to take over the crankcase pressure Pc is in a side portion of a first housing 1011 of the pressure sensing part 1010 intended. Furthermore, there is a passage 1013 which is in flow communication with the delivery chamber so as to receive a delivery pressure Pdh2 in a side portion of the first body 1004 intended. Also, in a coolant line that is connected to the passage 1013 and the passage 1012 is in flow communication, a first valve portion 1007 intended.

On the other hand, a side portion of the second body 1005 with a passage 1014 provided communicating with the coolant outlet of the compressor in fluid communication so that it assumes a delivery pressure Pd1 from an upper side, as well as with a passage communicating with the delivery chamber for transferring the delivery pressure Pdh 1015 , Also, in a coolant line, which is a flow connection between the passage 1015 and the passage 1014 produces, a second valve section 1008 intended.

In this case, the control valve 1001 be used with an adjustable compressor, which is constructed so that both passages, namely the passage 1015 to take over the delivery pressure Pdh and the passage 1013 to take over the delivery pressure Pdh2, in direct flow communication with the delivery chamber. Preferably, however, the control valve should be used with an adjustable compressor that is constructed so that the passage 1015 directly in fluid communication with the delivery chamber during the passage 1013 is in communication with an outlet of an oil separator, which is provided on the downstream side of the delivery chamber. Accordingly, the first valve portion 1007 Lubricating oil for the compressor, from which the refrigerant carries a considerable amount, to the crankcase, while the crankcase pressure Pc is controlled.

Between the first corpus 1004 and the second body 1005 is a membrane 1016 attached in such a way that it is clamped in a peripheral edge region and keeps these two parts airtight. An operating rod 1017 , which is guided by their center, is at the diaphragm 1016 attached; a detailed description will be given below.

For another, there is a core 1018 and a plunger 1019 of the electromagnet 1003 conically formed so that their faces facing each other in the axial direction each have a complementary shape and can hold a magnetic gap stable even when the two elements are removed from each other. It is also in an opening area at the top of the core 1018 a storage part 1020 fitted under pressure and supporting a portion near an upper end portion of the shaft 20 from.

As shown in 28 forms a peripheral inner surface of a flange portion, which extends to the inside, in a central region in the axial direction of the first body 1004 a valve opening 1021 while one edge at the lower opening end has a first valve seat 1022 forms. The operating rod 1017 is through the valve opening 1021 carried out. The operating rod 1017 is formed in a stepped cylindrical shape and is through the membrane 1016 on a side slightly lower than the middle in the axial direction. A top and bottom of the membrane 1016 be from a pair of slices 1023 clamped from the outside to the operating rod 1017 whereby an effective pressure take-up area of the membrane 1016 is defined. Besides, the two discs are 1023 attached in such a way that they are separated by a step portion of the actuating rod 1017 and a first valve element 1025 be clamped under pressure in the operating rod 1017 is fitted. In other words, the operating rod becomes 1017 from the membrane 1016 supported in the manner that it is displaceable in the axial direction. The first valve element 1025 is shaped so that it is unhindered close to the first valve seat 1022 and is movable away from it in such a way that it from the side of the delivery chamber ago the first valve seat 1022 opposite; Here is the first valve section 1007 together with the first valve seat 1022 built up.

At an upper portion of the operating rod 1017 is a spring receiving part under pressure 1026 appropriate. A feather 1027 is between the spring receiving part 1026 and the first corpus 1004 used. The feather 1027 Clamps the operating rod 1017 and the first valve element 1025 over the spring receiving part 1026 in valve closing direction. An upper end of the operating rod 1017 can at the disc 355 Part of the pressure sensing 1010 be set and solved by this. On the other hand, a lower end portion of the operating rod extends 1017 inside the second body 1005 , wherein a securing section 1028 which protrudes slightly in the radial direction, is formed at a front end thereof.

On the other hand, in the second corpus 1005 a cylindrical guide part 1031 fitted under pressure. The cylindrical guide part 1013 has an inner diameter which is approximately equal to the diameter of the receptacle of the membrane. An opening edge at the upper end of the guide part 1031 forms a second valve seat 1032 , Also, on an inside of the second body 1005 a stepped cylindrical second valve element 1033 and a stepped cylindrical guide 1034 arranged with closed end, which is inserted under pressure therein. The second valve element 1033 is from a conical surface near an upper end portion thereof to the second valve seat 1032 moving towards and away from it. The leadership 1034 is at a lower end portion of the second valve element 1033 secured by an upper end portion. The leadership 1034 Expands toward a lower side and is in sliding contact with the guide member from a lower end portion 1032 brought. The leadership 1034 is from the bottom of the shaft 20 supported. Near a lower section, with which the shaft 20 in the lead 1034 is in contact, is a connection opening 1036 educated. In addition, through the lower portion of the second valve element 1033 a security section 1028 guided the actuating rod and arranged in a free space between the second valve element 1033 and the leadership 1034 is trained. Accordingly, the second valve element 1033 on the security section 1028 depending on the movement of the actuating rod 1017 secured in the way that it together with the operating rod 1017 can be operated. In addition, between the guide part 1031 and the leadership 1034 a feather 1035 used the leadership 1034 and the second valve element 1033 stretched by expansion in the valve closing direction.

In this case, the electromagnet is 1003 according to this embodiment, between the core 1018 and the plunger coil 1019 the spring is not provided because the shaft 20 and the plunger coil by the extension of the spring 1035 be stretched down.

At the control valve 1001 then pushes when the electromagnet 1003 no power is supplied, the spring 1035 the second valve element 1033 to a lower side so down that the second valve section 1008 is set in the fully closed state, and pushes the second valve element 1033 the operating rod 1017 over the securing section so down to a lower side that the first valve section 1007 is brought into the fully open state. Accordingly, the compressor goes into the operating state with the smallest capacity. As the second valve element 1033 and the security section 1028 the operating rod 1017 are set, at this time, the refrigerant pipe, in the middle of the second valve element 1033 and the leadership 1034 is formed, closed. Since the standing under the discharge pressure Pdh coolant over a margin between the guide 1034 and the leadership part 1031 exit, also reaches the inside of the electromagnet 1003 a pressure that is close to the delivery pressure Pdh.

Will the electromagnet 1003 Power supplied, pushes the shaft 20 the second valve element 1033 about the leadership 1034 up to an upper side, so the second valve section 1008 to open. At this time, also pushes the spring 1027 the operating rod 1017 upwards, while this with the pushing up of the second valve element 1033 is busy. When the first valve element 1025 on the first valve seat 1022 touches, reaches the first valve section 1007 the valve closing state. Accordingly, the compressor then begins the transition to the operating state with the largest capacity. When the operating rod 1017 from the second valve element 1033 is removed, at this time, the coolant line, which is in the middle of the second valve element 1033 and in the lead 1034 is formed, opened and becomes a flow connection between the inner portion of the electromagnet 1003 and the passage 1014 made so that the discharge pressure Pdl is achieved.

When the control current during the activation of the electromagnet 1003 is held at a predetermined value so that the magnet is energized becomes the second valve element 1033 held in a position in which the force of the electromagnet, which corresponds to the predetermined value, and that of the spring 1035 generated clamping force are balanced. Accordingly, the second valve portion 1008 formed passage set to a predetermined cross-sectional value. Since the coolant through the second valve section 1008 flows over the second valve section 1008 a predetermined differential pressure (ΔP = Pdh - Pdl) generated.

The diaphragm also detects the differential pressure ΔP and the first valve element 1025 is from the first valve seat 1022 raised by a predetermined amount, so the first valve element 1025 to set to a predetermined valve opening state. When the flow rate through the second valve section 1008 flowing refrigerant and the differential pressure .DELTA.P assumes a high value, at this time detects the membrane 1016 this constellation and opens the second valve section 1008 still further and drives the compressor in a direction in which the delivery capacity is lowered. On the other hand, when the flow rate of the refrigerant decreases and the differential pressure ΔP becomes small, the diaphragm detects 1016 this constellation and then changes the second valve section 1008 in the valve closing direction and controls the compressor in a direction in which increases the delivery capacity. As already stated, the compressor is controlled in such a way that it conveys the coolant at a flow rate which corresponds to the control current which corresponds to the electromagnet 1003 is supplied.

If also at the control valve 1001 the crankcase pressure Pc becomes lower than the preset pressure value due to the decrease of the suction pressure Ps, the diaphragm becomes 52 by the tension of the spring 53 shifts down and gets the power over the disc 355 , the operating rod 1017 and the leadership 1034 on the wave 20 transfer. Accordingly, the force in the direction in which the force Fs of the solenoid becomes lower is applied and becomes the first valve element 1025 in the valve opening direction plants. As a result, the crankcase pressure Pc increases, the discharge capacity of the compressor decreases, and the suction pressure Ps increases.

At the control valve 1001 According to the embodiment described here, the crankcase pressure Pc is monitored while the control of the initial capacity is executed. When the crankcase pressure Pc becomes lower than the preset pressure value, the pressure detecting part generates 1010 the force in the direction in which the force of the electromagnet decreases. As already mentioned, due to the lowering of the suction pressure Ps, the discharge capacity of the compressor decreases by decreasing the force of the solenoid to make it easy to open the valve portion when the crankcase pressure Pc becomes lower than the preset pressure value, thereby making it possible to to prevent excessive cooling. In addition, because the pressure sensing part 1010 at one end of the first body 1004 is provided, the control valve can be 1001 achieve with a simple construction.

The preferred embodiments Although the present invention has been described, it will be understood it goes without saying that this invention is not limited to the specific Embodiments is limited but that in the context of the invention underlying technical In principle, various modifications and modifications possible are.

at the above embodiments For example, the membrane is made of a thin metal plate, for example Beryll copper, stainless steel or the like, but it can also of a plastic material such as polyimide or the like be made. In the latter case, it is possible to break resistance to increase, to Example by using a variety of polyimide films, the overlapping are arranged.

In this case, the control valve according to the above embodiments is preferably used in a refrigeration cycle in which a substitute for CFC substances (HFC-134a) or the like is used as the refrigerant; However, the control valve can also be used in a refrigeration cycle with a coolant having a high operating pressure, for example carbon dioxide. In this case, instead of the Kon densators arranged in the cooling circuit, a heat exchanger, such as a gas cooler or the like.

at The embodiments described above are the examples shown where the spring used as an elastic part and as a clamping part becomes; However, the elastic part and the clamping part can also from others Be constructed elements with elastic force.

Claims (18)

Control valve ( 1 ; 201 ; 301 ; 401 ; 501 ; 601 ; 701 ; 801 ; 901 ) for a variable displacement compressor that controls the flow rate of a refrigerant introduced from an exhaust chamber into a crankcase such that a differential pressure between two predetermined points in a refrigeration cycle is maintained at a preset differential pressure value and for varying an exhaust amount the coolant from the compressor, the control valve comprising: a body ( 5 ; 205 ; 305 ; 405 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ), in which a coolant passage is formed in an inner portion; a valve element ( 18 ; 218 ; 318 ; 418 ; 518 ; 618 ; 718 ; 816 ; 916 ), which is arranged in such a way that it is close to a valve opening ( 15 ; 507 ; 632 ; 812 ; 912 ), which forms the coolant passage, which brings the outlet chamber and the crankcase in such a way in flow communication, or can be located therefrom, so that a valve portion is opened and closed; a wave ( 20 ; 520 ), which in the axial direction a force on the valve element ( 18 ; 218 ; 318 ; 418 ; 518 ; 618 ; 718 ; 816 ; 916 ) transmits; an electromagnet ( 3 ; 503 ; 803 ), which in the valve closing direction, the on the shaft ( 20 ; 520 ) acting preset differential pressure in the axial direction, a force exerted by the electromagnet and the valve element ( 18 ; 218 ; 318 ; 418 ; 518 ; 618 ; 718 ; 816 ; 916 ) is operated in the opening and closing direction of the valve portion; a pressure chamber ( 25 ; 225 ; 325 ; 525 ), one of the body ( 5 ; 205 ; 305 ; 405 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ) and the electromagnet ( 3 ; 503 ; 803 enclosed space and in fluid communication with a suction chamber or the crankcase for introducing pressure into one of the two; and a pressure sensing section (FIG. 6 ; 206 ; 306 ; 406 ; 506 ; 640 ; 706 ; 807 ; 907 ) inside the body ( 5 ; 205 ; 305 ; 405 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ) or integral with the body ( 5 ; 205 ; 305 ; 405 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ) is adapted to one in the pressure chamber ( 25 ; 225 ; 325 ; 525 ) and which generates a force in a direction in which the force of the electromagnet is reduced when the pressure in the pressure chamber ( 25 ; 225 ; 325 ; 525 ) prevailing pressure is lower than the preset pressure. A control valve according to claim 1, wherein said pressure sensing portion (16) 6 ; 206 ; 506 ; 640 ; 706 ; 807 ; 907 ) comprises: a housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) on the shaft ( 20 ; 520 ) is stored so that it is within the pressure chamber ( 25 ; 225 ; 525 ) is displaceable; a flexible part ( 52 ; 711 ; 831 ), which is provided in such a way that it is an inside of the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) in a sealed room and in a space communicating with the pressure chamber ( 25 ; 225 ; 525 ) is divided and thereby deformed in a direction in which it moves away from the shaft ( 20 ; 520 ) moves away when one in the pressure chamber ( 25 ; 225 ; 525 ) prevailing pressure becomes lower than the preset pressure; an elastic part ( 53 ; 724 ) between the flexible part ( 52 ; 711 ; 831 ) and the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) is arranged; and a part for transmitting a reaction force ( 55 ; 555 ; 722 ; 818 ; 918 ) with a leg section ( 54 ; 819 ; 919 ), which on an opposite side to the shaft ( 20 ; 520 ) in the flexible part ( 52 ; 711 ; 831 ) and to an outer portion of the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) and constructed in such a way that the leg portion ( 54 ; 819 ; 919 ) by the deformation of the flexible part ( 52 ; 711 ; 831 ) directly or indirectly on the body ( 5 ; 205 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ) presses when in the pressure chamber ( 25 ; 225 ; 525 ), the prevailing pressure becomes lower than the preset pressure, and the reaction force transmitting part applies a force to the shaft (FIG. 20 ; 520 ) in a direction in which the force of the electromagnet is reduced, via the elastic part ( 53 ; 724 ) and the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) with the reaction force. Control valve according to Claim 2, in which the valve element ( 18 ; 518 ; 916 ) of an end portion of an actuating rod ( 17 ; 517 ; 915 ) formed slidably into a in the body ( 5 ; 505 ; 905 ; 906 ) provided guide hole ( 19 ; 519 ; 921 ), and the housing ( 51 ; 551 ; 930 ) of the pressure sensing section ( 6 ; 506 ; 907 ) is arranged in such a way that between the other end portion of the actuating rod ( 17 ; 517 ; 915 ) and the wave ( 20 ; 520 ) is used. Control valve according to Claim 3, in which a clamping part ( 560 ), which the actuating rod ( 517 ) in the valve opening direction, within the pressure chamber ( 525 ) is provided. Control valve according to Claim 2, in which a cylindrical abutment part ( 511 ; 817 ) with ge closed end, which is adjustably fixed in position inside the body ( 505 ; 805 . 806 ) is provided, and the leg portion ( 54 ; 819 ) of the pressure sensing section ( 506 ; 807 ) is constructed in such a way that it to a lower portion of the abutment part ( 511 ; 817 ) is movable towards and away from this. Control valve according to Claim 2, in which the valve element ( 218 ; 618 ) from a part of the housing ( 251 ; 641 ) of the pressure sensing section ( 206 ; 640 ) is constructed. Control valve according to Claim 1, in which the valve element ( 318 ) integral in one end of the shaft ( 20 ) is provided, and the pressure sensing section ( 306 ) comprises: a housing ( 351 ) fixed in such a way that it has an end portion of the body ( 305 ) seals; a flexible part ( 52 ), which is provided in such a way that it has an inner portion of the housing ( 351 ) in a sealed room and in a space communicating with the pressure chamber ( 325 ) is divided and deformed in a direction in which it is close to the shaft ( 20 ) is moved when one in the pressure chamber ( 325 ) prevailing pressure becomes lower than the preset pressure; an elastic part ( 53 ), which is arranged in the sealed space and the flexible part ( 52 ) to the side of the shaft ( 20 ) and a part for transmitting a decreasing force ( 355 ; 316 ) with a transmission rod ( 316 ), which are on the side of the shaft ( 20 ) of the flexible part ( 52 ) is provided and to an outer portion of the housing ( 351 ) and constructed in such a way that the transmission rod by deformation of the flexible part ( 52 ) to the shaft ( 20 ) applies a force in one direction to reduce the force of the electromagnet when in the pressure chamber ( 325 ) prevailing pressure is lower than the preset pressure. Control valve according to Claim 1, in which the valve opening ( 15 ) from an internal passage of a movable part ( 414 ), which forms a valve seat and is provided in a coolant passage, which establishes a flow connection between the outlet chamber and the crankcase, such that a forward movement and a backward movement are possible; the valve element ( 418 ) of an end portion of an actuating rod ( 417 ) formed inside the body ( 405 ) works in the axial direction; the pressure sensing section ( 406 ) comprises: a housing ( 51 ), which in the way at the wave ( 20 ) is stored in the interior of the pressure chamber ( 25 ) is displaceable; a flexible part ( 52 ), which is provided in such a way that it is an inside of the housing ( 51 ) is subdivided into a sealed space and into a space communicating with the pressure chamber ( 25 ), thereby deforming in a direction in which it is different from the world ( 20 ) moves away when in the pressure chamber ( 25 ) prevailing pressure becomes lower than the preset pressure; and an elastic part ( 53 ) between the flexible part ( 52 ) and the housing ( 51 ), and a part for transmitting a reaction force ( 423 ) with a leg section ( 426 ), which on an opposite side to the shaft ( 20 ) in the flexible part ( 52 ) and to an outer portion of the housing ( 51 ) and constructed in such a way that the leg portion ( 426 ) by the deformation of the flexible part ( 52 ) on the moving part ( 414 ) presses to form a valve seat when in the pressure chamber ( 25 ) prevailing pressure becomes lower than the preset pressure, and the part for transmitting a reaction force to the shaft (FIG. 20 ) a force in one direction to reduce the force of the electromagnet via the elastic member (FIG. 53 ) and the housing ( 51 ) with the reaction force, and the housing ( 51 ) of the pressure sensing section ( 406 ) is arranged in such a way that between the other end portion of the actuating rod ( 417 ) and the wave ( 20 ) is used. A control valve according to claim 1, wherein the differential pressure between two points is constituted by a differential pressure between an outlet pressure of the outlet chamber and a suction pressure of the suction chamber, and the pressure chamber (12). 25 ; 325 ; 525 ) is constructed to be fluidly connected to the suction chamber to introduce the suction pressure. A control valve according to claim 1, wherein the differential pressure between two points is formed by a differential pressure between an outlet pressure of the outlet chamber and an outlet pressure of the compressor, and the pressure chamber (12). 25 ) is constructed in such a way that it is brought into fluid communication with the crankcase to initiate a crank pressure. A control valve according to claim 1, wherein said pressure sensing portion (16) 6 ; 206 ; 306 ; 406 ; 506 ; 807 ; 907 ) a membrane ( 52 ; 831 ) having. A control valve according to claim 1, wherein said pressure sensing portion (16) 706 ) a bellow ( 711 ) having. Control valve ( 1 ; 201 ; 301 ; 401 ; 501 ; 601 ; 701 ; 801 ; 901 ; 1001 ) for a variable displacement compressor which controls the flow rate of a refrigerant introduced from an outlet chamber of the compressor into a crankcase and which varies an outlet amount of the compressor, the control valve comprising: a body ( 5 ; 205 ; 305 ; 405 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ; 1004 . 1005 ), in which a coolant passage is formed in an inner portion; a valve element ( 18 ; 218 ; 318 ; 418 ; 518 ; 618 ; 718 ; 816 ; 916 . 1025 ), which is arranged in such a way that it is close to a valve opening ( 15 ; 507 ; 632 ; 812 ; 912 ; 1021 ), which valve opening forms the coolant passage, which brings the outlet chamber and the crankcase in fluid communication, so that a valve portion is opened and closed; a wave ( 20 ; 520 ), which in the axial direction a force on the valve element ( 18 ; 218 ; 318 ; 418 ; 518 ; 618 ; 718 ; 816 ; 916 . 1025 ) transmits; an electromagnet ( 3 ; 503 ; 803 . 1003 ) which is capable of, in a valve closing direction of the valve portion to the shaft ( 20 ; 520 ) apply a force of the electromagnet and the valve element ( 18 ; 218 ; 318 ; 418 ; 518 ; 618 ; 718 ; 816 ; 916 , 1025 ) in an opening and closing direction of the valve portion; a pressure chamber ( 25 ; 225 ; 325 ; 525 ), which communicates with a suction chamber or the crankcase of the compressor in fluid communication, so that in one of the two a pressure is introduced; and a pressure sensing section (FIG. 6 ; 206 ; 306 ; 406 ; 506 ; 640 ; 706 ; 807 ; 907 ; 1010 ) inside the body ( 5 ; 205 ; 305 ; 405 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ; 1004 . 1005 ) or integral with the body ( 5 ; 205 ; 305 ; 405 ; 505 ; 605 ; 705 ; 805 . 806 ; 905 . 906 ; 1004 . 1005 ) is adapted to one in the pressure chamber ( 25 ; 225 ; 325 ; 525 ) and a force is generated in a direction in which the force of the electromagnet is reduced when in the pressure chamber ( 25 ; 225 ; 325 ; 525 ) prevailing pressure is lower than the preset pressure. A control valve according to claim 13, wherein said pressure detecting section (16) 6 ; 206 ; 506 ; 640 ; 706 ; 807 ; 907 ) comprises: a housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) on the shaft ( 20 ; 520 ) is stored so that it is within the pressure chamber ( 25 ; 225 ; 525 ) is displaceable; a flexible part ( 52 ; 711 ; 831 ), which is provided in such a way that it is an inside of the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) is subdivided into a sealed space and into a space communicating with the pressure chamber ( 25 ; 225 ; 525 ), thereby deforming in a direction in which it moves away from the shaft ( 20 ; 520 ) moves away when one in the pressure chamber ( 25 ; 225 ; 525 ) prevailing pressure becomes lower than the preset pressure; an elastic part ( 53 ; 724 ) between the flexible part ( 52 ; 711 ; 831 ) and the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ): a part for transmitting a reaction force ( 55 ; 555 ; 722 ; 818 ; 918 ) with a leg section ( 54 ; 819 ; 919 ), which on an opposite side to the shaft ( 20 ; 520 ) in the flexible part ( 52 ; 711 ; 831 ) and to an outer portion of the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) and constructed in such a way that the leg portion ( 54 ; 819 ; 919 ) due to the deformation of the flexible part ( 52 ; 711 ; 831 ) directly or indirectly on the body ( 5 ; 205 ; 505 ; 605 ; 705 ; 805 ; 806 ; 905 ; 906 ) presses when in the pressure chamber ( 25 ; 225 ; 525 ) prevailing pressure becomes lower than the preset pressure, and the reaction force transmitting part applies a force to the shaft (FIG. 20 ; 520 ) in a direction to reduce the force of the electromagnet via the elastic member (FIG. 53 ; 724 ) and the housing ( 51 ; 251 ; 551 ; 641 ; 712 ; 830 ; 930 ) with the reaction force. Control valve according to Claim 13, in which the control valve is also located next to the valve or valve section (Fig. 1007 ) with an additional valve section ( 1008 ), which controls a flow rate of the coolant circulating from the discharge chamber to a refrigerant outlet of the compressor, the valve portion (FIG. 1007 ) controls the flow rate of the coolant, which by means of the additional valve section ( 1008 ) is circulated by controlling a flow rate of the refrigerant circulating from the discharge chamber to the crankcase, based on a differential pressure across the additional valve portion so as to change an outlet amount of the compressor, and the solenoid ( 1003 ) the additional valve section ( 1008 ) is actuated in such a way that the flow rate of the coolant flowing from the additional valve section ( 1008 ), reaches a preset throughput value. Control valve according to Claim 14, in which the flexible part ( 831 ) from a membrane ( 831 ) is formed, and the elastic part of a plate spring ( 832 ), along the membrane ( 831 ) is arranged. Control valve according to Claim 16, in which the diaphragm spring ( 832 ) has a shape in which a central portion to a side of the part for transmitting a reaction force ( 818 ; 918 protruding, and that the direction in which the central region protrudes, around a peripheral edge portion, as Support point is reversed, so that it is deformable. Control valve according to claim 17, in which an inner wall of the housing ( 830 ; 930 ) is formed in a shape which extends approximately along a shape in which the plate spring ( 832 ) is reversed to deformation.