KR101043232B1 - Displacement control valve of variable displacement compressor - Google Patents

Abstract

In the displacement control valve of the variable displacement compressor of the present invention, in the displacement control valve of the variable displacement compressor, a crank chamber connection hole and a discharge chamber connection hole respectively receiving the crank chamber pressure and the discharge chamber pressure of the compressor are respectively formed therein. A valve housing formed so that the first guide hole crossing the discharge chamber connecting hole and the crank chamber connecting hole penetrates, and a valve body configured to open and close the inlet of the first guide hole with one end reciprocating toward the inlet of the first guide hole. An electromagnetic solenoid for reciprocating the valve body by means of; And a sleeve coupled to one end of the valve body, the sleeve penetrating the first guide hole and coupled to the valve housing so as to be movable relative to the valve housing, wherein the sleeve is connected to one end of the valve body. A small diameter portion to be coupled, and a larger diameter than the small diameter portion, characterized in that consisting of a large diameter portion coupled to the valve housing so as to allow relative movement.

Accordingly, since the opening amount of the valve body is limited by the sleeve, even if the discharge pressure Pd is increased, the suction pressure Ps is maintained at a constant value, thereby improving the control precision and between the large diameter portion of the sleeve and the valve housing during processing. Can be precisely matched to prevent the discharge pressure from leaking into the space where the suction pressure acts to adversely affect.

Variable displacement compressor, displacement control valve, discharge pressure, suction pressure, sleeve

Description

Capacity control valve of variable displacement compressor {DISPLACEMENT CONTROL VALVE OF VARIABLE DISPLACEMENT COMPRESSOR}

The present invention relates to a capacity control valve of a variable displacement compressor, and more particularly, a capacity control of a variable displacement compressor in which the suction pressure (Ps) is maintained to be a constant value even when the discharge pressure (Pd) is increased to improve the control precision. It is about a valve.

Since the compressor included in the cooling system of the automotive air conditioner is directly connected to the engine through the belt, the rotation speed cannot be controlled.

Therefore, in recent years, a variable capacity compressor that can change the discharge amount of the refrigerant to obtain a cooling capacity without being regulated by the rotational speed of the engine has been used a lot.

Various types of variable displacement compressors are disclosed, such as swash plate type, rotary type and scroll type.

In the swash plate type compressor, the swash plate provided so that the inclination angle is variable in the crank chamber rotates according to the rotational motion of the rotating shaft, and the piston reciprocates by the rotational motion of the swash plate. In this case, the refrigerant in the suction chamber is sucked into the cylinder by the reciprocating motion of the piston, compressed and discharged into the discharge chamber. The inclination angle of the swash plate is changed according to the pressure difference in the crank chamber and the pressure in the suction chamber, and the discharge amount of the refrigerant is Will be controlled.

In particular, by adopting an electromagnetic solenoid type capacity control valve to open and close the valve by energization to adjust the pressure of the crank chamber, through this to adjust the inclination angle of the swash plate to adjust the discharge capacity.

A representative example of a capacity control valve of such a variable displacement compressor is disclosed in Patent Document 1 (hereinafter referred to as "prior art"), and a schematic configuration thereof will be described with reference to FIGS. .

As shown, the capacity control valve 5 according to the prior art has a shaft portion 15c, a valve body having a diameter smaller than the middle small diameter portion 15b and a diameter larger than the shaft portion 15c than the shaft portion 15c. A valve rod 15 having a portion 15a, a guide hole 19 into which the shaft portion 15c of the valve rod 15 is inserted so as to be free to slide, and a valve body portion 15a are provided at their lower ends (valve). The discharge pressure Pd from the compressor to the valve chamber 21 provided with the valve opening 22 separated from the seat 22a, and the outer peripheral part (upstream of the valve opening 22) of the valve chamber 21. A discharge pressure refrigerant inlet port 25 with a plurality of filters 25A for introducing refrigerant of the refrigerant is provided, and is continuously connected to the crank chamber of the compressor at the lower side (downstream side) of the valve port 22. The valve body 20 and the electronic actuator 30 provided with the refrigerant | coolant outlet 26 are provided.

The electromagnetic actuator 30 includes a coil 32 having a connector portion 31 for power transmission, a cylindrical stator 33 disposed on an inner circumferential side of the coil 32, and a stator 33. A pipe having a concave aspirator 34 having a concave end face press-fitted to the lower end inner circumference and a flange-shaped portion 35a whose upper end is joined to the outer circumference (step difference) of the stator 33 by TIG welding ( 35 and the plunger 37 and the bottom disposed to cover the outer circumference of the coil 32 are arranged on the inner circumferential side of the pipe 35 so as to be free to slide up and down on the inner circumferential side of the suction 34. A cylindrical housing 60 having a hole therein is provided.

Moreover, the adjustment screw 65 which has a hexagonal hole is screwed on the upper part of the said stator 33, and is between the said adjustment screw 65 and the aspirator 34 in the inner peripheral side of the stator 33. Moreover, as shown in FIG. The decompression chamber 45 is formed in which the suction pressure Ps of the compressor is introduced, and the decompression chamber 45 is provided with a bellows 41 as a member moving in accordance with the decompression, and has an inverted convex upper stopper 42. ), A bellows main body 40 composed of an inverted lower stopper 43 and a compression coil spring 44 is disposed.

And between the bellows main body 40 and the aspirator 34, the compression coil spring 46 which presses in the direction which contracts the bellows main body 40 (the direction compressed to the adjustment screw 65 side) is arrange | positioned. It is. In addition, between the lower stopper 43 (recess recess) of the bellows body 40 and the recess 37c of the plunger 37, an operating rod 14 penetrating the suction 34 is disposed. Between the suction 34 and the plunger 37 (concave portion 37b), a valve comprising a compression coil spring for pressing the valve rod 15 downward (valve opening direction) through the plunger 37. An opening spring 47 is arranged.

On the other hand, in the upper center of the valve body 20, a convex stopper portion 28 protruding from the lowermost position of the plunger 37 protrudes and is installed, and includes a valve including the convex stopper portion 28. In the center portion of the upper thread, a guide hole 19 into which the valve rod 15 is inserted so as to slide freely is formed. Further, between the plunger 37 and the upper outer circumference (the outer circumference of the convex stopper portion 28) of the valve body 20, a suction pressure refrigerant introduction chamber 23 through which the refrigerant at the suction pressure of the compressor is introduced is formed. A plurality of suction pressure refrigerant inlets 27 are formed on the outer circumferential side thereof, and the refrigerant at the suction pressure Ps introduced into the suction pressure refrigerant introduction chamber 23 from the suction pressure refrigerant inlet 27 is a plunger. The decompression chamber 45 through the vertical grooves 37a, 37a, ... formed on the outer circumference of the 37 and the continuous passage hole 37d protruding from the center portion, the continuous passage hole 39 formed in the aspirator 34, and the like. Is introduced.

The valve closing spring 48 which consists of a conical compression coil spring which presses the said valve rod 15 upward is arrange | positioned in the lower part (refrigerant outlet 26) of the said valve main body 20, The said valve closing spring By the pressing force of 48, the upper end part of the valve rod 15 is always pressed against the plunger 37 (continuous passage hole 37d part).

In addition, a lower flange portion 35a of the pipe 35 is placed on the upper end portion of the valve body 20 through an O-ring 57, and between the flange portion 35a and the coil 32. A short cylindrical pipe holder 56 with a flanged portion 56a is fitted therein, and the flanged portions 35a and 56a are all fastened by the upper outer circumferential caulking portion 29 of the valve body 20. It is fixed.

In addition, the upper end portion of the pipe holder 56 is press-fitted and fixed with a bottom portion 61 having a hole in the housing 60, and the upper end portion 62 of the housing 60 has a flange shape of the connector portion 31. A caulking is fixed on the portion 31c, and a zero ring 66 is fitted between the housing 60 and the connector portion 31 and the coil 32. Moreover, the recessed part 31a in which the convex part 31b which fits in the hexagonal hole of the said adjustment screw 65 protrudes is formed in the center lower part of the connector part 31, and this recessed part 31a is provided. The upper part of the stator 33 and the adjustment screw 65 is inserted into the.

In the control valve 5 comprised in this way, when the solenoid part which consists of the coil 32, the stator 33, and the suction 34 is energized, the plunger 37 will be attracted to the suction 34. As shown in FIG. As a result, the valve rod 15 can move upward (valve closing direction) by the pressing force of the valve closing spring 48.

On the other hand, the refrigerant of the suction pressure Ps introduced from the compressor to the suction pressure inlet 27 is formed in the longitudinal grooves 37a, 37a, ... and suction formed on the outer circumference of the plunger 37 from the introduction chamber 23. The bellows main body 40 (internal vacuum pressure) is introduced into the decompression chamber 45 through the continuous passage hole 39 formed in the 39, and the pressure (suction pressure Ps) of the decompression chamber 45. Expansion and contraction (shrinkage when the suction pressure Ps is high and elongate when the suction pressure Ps is high), the displacement is transmitted to the valve rod 15 through the operating rod 14 and the plunger 37, thereby opening the valve. (The lift amount of the valve body part 15a from the valve seat part 22a of the valve port 22) is adjusted.

That is, the valve opening degree is the suction force of the plunger 37 by the solenoid part which consists of the coil 32, the stator 33, and the suction 34, the pressing force of the bellows main body 40, and the valve opening spring ( 47) and the pressing force by the valve closing spring 48, the valve opening direction load by the discharge pressure Pd with respect to the valve shaft 15, and the valve closing direction load, and are discharged according to the valve opening degree. The amount of condensation of the refrigerant of the discharge pressure Pd introduced into the valve chamber 21 from the pressurized refrigerant introduction port 25, that is, the amount of condensation (condensation amount) into the crank chamber is adjusted. In other words, the pressure Pc on the refrigerant outlet 26 side, that is, the pressure in the crank chamber, is controlled in accordance with the valve opening degree, thereby adjusting the inclination angle of the inclined plate of the compressor and the stroke of the piston, thereby increasing and decreasing the discharge amount. .

However, the capacity control valve 5 for the variable displacement compressor according to the prior art has a problem to be improved as follows.

That is, in the control valve 5, the discharge pressure refrigerant inlet 21 is provided upstream of the valve port 22, and the refrigerant outlet 26 is provided downstream of the valve port 22, and the valve main body is provided. The portion 15a is provided at the lower end of the shaft portion 15c of the valve rod 15 to open and close the valve opening 22 from the lower side thereof, and the discharge pressure Pd acts on the valve rod 15. have.

In this case, in order to facilitate valve assembly, as shown schematically in Figs. 2A and 2B, the valve port 22 moves the shaft portion 15c of the valve rod 15 to its lower portion. The aperture Da is made slightly larger than the outer diameter Db of the shaft portion 15c so as to pass through from the lower side, and also to open and close the valve opening 22 from the lower side in the valve body portion 15a. The outer diameter Dc of the valve main body 15a is the diameter Da of the valve port 22 (so that the valve main body 15a is in contact with and separated from the valve seat 22a provided at the lower end of the valve port 22). It becomes larger (Db <Da <Dc).

In this case, the valve closing direction load (pushing force) A by the discharge pressure Pd acting on the valve rod 15 depends on the hydraulic pressure area (outer diameter Db) of the shaft portion 15c. The opening direction load (pushing force) B is applied to the load Ba along the diameter Da of the valve port 22 (valve seat portion 22a) to the outer diameter Dc (Dc-Da) of the valve body portion 15a. The load Bb according to this is added magnitude.

Here, since Da and Db may be assumed to be approximately equal, the valve opening direction load (pushing force) due to the discharge pressure Pd to the valve rod 15 is greater than the valve closing direction load (pushing force). Bb is large. Therefore, if the current value I supplied to the coil 32 of the electronic actuator 30 is made constant, the discharge pressure Pd is increased by the (Pd)-(Ps) characteristics shown in FIG. Pc) Furthermore, the suction pressure Ps (on the use of the compressor, the outlet pressure Pc and the suction pressure Ps are approximately equal) also tends to be high (upper right), which adversely affects the control (control There is a problem).

[Patent Document 1] Japanese Unexamined Patent Publication No. 2006-291867

The present invention has been made to solve the above-mentioned conventional problems, the object of the present invention is configured to maintain a constant value of the suction pressure (Ps) even if the discharge pressure (Pd) is increased capacity variable deformation improved control accuracy To provide a capacity control valve of the compressor.

In addition, another object of the present invention is to provide a capacity control valve of a variable displacement compressor that adjusts the discharge capacity by using the equilibrium relationship between the differential pressure of the discharge chamber and the suction chamber, the force of the bellows and the solenoid.

The capacity control valve of the variable displacement compressor of the present invention for achieving the above object is, in the capacity control valve of the variable displacement compressor, the crank chamber connecting hole and the discharge chamber connecting hole which receives the crank chamber pressure and the discharge chamber pressure of the compressor, respectively The valve housing is formed inside each of the valve housing formed so that the first guide hole crossing the discharge chamber connecting hole and the crank chamber connecting hole, and the inlet of the first guide hole with one end reciprocating toward the inlet of the first guide hole. A valve body configured to open and close, an electromagnetic solenoid for reciprocating the valve body by energization; And a sleeve coupled to one end of the valve body, the sleeve penetrating the first guide hole and coupled to the valve housing so as to be movable relative to the valve housing, wherein the sleeve is connected to one end of the valve body. A small diameter portion to be coupled, and a larger diameter than the small diameter portion, characterized in that consisting of a large diameter portion coupled to the valve housing so as to allow relative movement.

Here, the small diameter portion of the sleeve is preferably pressed or screwed to one end of the valve body.

And, the large diameter cross-sectional area of the sleeve,

It is preferable that the sum of the cross-sectional area of the first guide hole and the cross-sectional area of the valve body is equal to or larger than the value obtained by dividing by two.

Or, it is preferable that the large diameter cross section of the said sleeve is the same as the cross section of the valve body.

In addition, the large diameter portion of the sleeve is characterized in that the bellows is further provided.

In this case, the bellows is preferably fixed to the sleeve to prevent relative movement.

And, it is preferable that the cap is screwed with the valve housing so as to surround the bellows.

In addition, the support spring is preferably provided between the bellows and the valve housing.

On the other hand, the method of assembling the capacity control valve of the variable displacement compressor according to the present invention described above,

Coupling the solenoid with the valve body and the valve housing, press-fit or screw the small diameter portion of the sleeve to one end of the valve body exposed to one side of the valve housing, and couple the bellows to the large diameter end of the sleeve, Fixing the valve housing and the cap to cover the bellows.

According to the capacity control valve of the variable displacement compressor according to the present invention, since the opening amount of the valve body is limited by the sleeve, even if the discharge pressure (Pd) is increased, the suction pressure (Ps) maintains a constant value, thereby improving the control accuracy have.

In addition, there is an effect of adjusting the discharge capacity by using the equilibrium relationship between the differential pressure of the discharge chamber and the suction chamber, the force of the bellows and the electromagnetic solenoid.

That is, according to the present invention, the magnitude of the current acting on the electromagnetic solenoid is proportional to the difference between the discharge pressure and the suction pressure, and thus, the discharge capacity and the torque can be easily adjusted.

Further, according to the present invention, since the small diameter portion of the sleeve is press-fitted or screwed to one end of the valve body, and the large diameter portion of the sleeve moves relative to the valve housing, the large diameter portion of the sleeve changes when the valve body and the sleeve are coupled. In this case, the discharge pressure can be effectively prevented from leaking between the large diameter portion of the sleeve and the valve housing to the space where the suction pressure is applied. That is, it is easy to manage the large diameter part size of a sleeve.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 is a longitudinal sectional view showing a structure of a variable displacement compressor according to the present invention, Figure 5 is a longitudinal sectional view showing the structure of a capacity control valve in Figure 4, Figure 6 is a cross-sectional view between each component in the capacity control valve of Figure 4 Longitudinal cross-sectional view showing the balance of forces.

First, the structure of the variable displacement swash plate type compressor provided with a capacity control valve according to the present invention will be described schematically.

As shown, the variable displacement swash plate type compressor C has a cylinder block 10 having a plurality of cylinder bores 12 formed parallel to the inner circumferential surface in the longitudinal direction, and sealed in front of the cylinder block 10. The front housing 16 is coupled, and the rear housing 18 is hermetically coupled to the rear of the cylinder block 10 via a valve plate 20.

The crank chamber 86 is provided inside the front housing 16, and one end of the drive shaft 44 is rotatably supported near the center of the front housing 16, while the other end of the drive shaft 44 is Passed through the crank chamber 86 is supported via a bearing provided in the cylinder block 10.

In the crank chamber 86, the lug plate 54 and the swash plate 50 are provided around the drive shaft 44.

In the lug plate 54, a pair of power transmission support arms 62 each having a linearly perforated guide hole 64 formed at the center thereof are formed to protrude integrally on one surface, and one surface of the swash plate 50 has a ball. As the lug plate 54 rotates, the ball 66 of the swash plate 50 slides in the guide hole 64 of the lug plate 54 so that the swash plate 50 can be rotated. The inclination angle is variable.

In addition, the outer circumferential surface of the swash plate 50 is fitted to the piston 14 so as to be able to slide through the shoe 76.

Accordingly, as the swash plate 50 rotates in an inclined state, the pistons 14 fitted through the shoe 76 on the outer circumferential surface thereof are reciprocated in each cylinder bore 12 of the cylinder block 10. do.

In addition, a suction chamber 22 and a discharge chamber 24 are formed in the rear housing 18, and each cylinder bore is provided in the valve plate 20 interposed between the rear housing 18 and the cylinder block 10. A suction port 32 and a discharge port 36 are respectively formed in a position corresponding to (12).

By the reciprocating motion of the piston 14, the refrigerant in the suction chamber 22 is sucked into the cylinder bore 12, compressed, and discharged to the discharge chamber 24. The pressure in the crank chamber 86 and the suction chamber ( The inclination angle of the swash plate 50 is changed according to the pressure difference in the 22 to adjust the discharge amount of the refrigerant.

Specifically, the variable displacement compressor adopted in the embodiment of the present invention adopts the electromagnetic solenoid type capacity control valve 100 to adjust the pressure of the crank chamber 86 by opening and closing the valve by energization, through which the swash plate 50 ) To adjust the discharge capacity.

Hereinafter, the capacity control valve 100 according to the present invention will be described in detail.

As shown in FIG. 2, the capacity control valve 100 according to the present invention is installed to be movable in the valve housing 110, the electromagnetic solenoid 130, and the valve housing 110 in which some connection holes are formed. The valve body 120 is included.

In addition, a first guide hole 117 is formed in the valve housing 110 to guide the movement of the valve body 120. The electromagnetic solenoid 130 has a movable iron core 131 and a valve body (to be described later). The second guide hole 137 for guiding the movement of the 120 is formed.

In particular, as the electromagnetic solenoid 130 is energized, the valve body 120 is configured to open and close the first guide hole 117 formed in the valve housing 110 while reciprocating.

The valve housing 110 is formed with a crank chamber connecting hole 112 and a discharge chamber connecting hole 113 in which the pressure Pc of the crank chamber 86 and the pressure Pd of the discharge chamber 24 respectively work. have. The discharge chamber connecting hole 113 and the crank chamber connecting hole 112 have a structure in communication with each other through the first guide hole 117.

In the drawing, the discharge chamber connecting hole 113 is formed in a direction orthogonal to the crank chamber connecting hole 112 and the suction chamber connecting hole 111, respectively, but the direction may be arbitrarily determined.

One end of the valve body 120 is capable of opening and closing while reciprocating the inlet of the first guide hole 117 connecting the discharge chamber connecting hole 113 and the crank chamber connecting hole 112.

Although not shown, it is preferable that the suction pressure Ps of the compressor C and the pressure Pc of the crank chamber 86 act on both ends of the valve body 120.

In addition, a sleeve 140 is coupled to one end of the valve body 120, wherein the sleeve 140 passes through the first guide hole 117 and crosses the discharge chamber connecting hole 113. Relative movement is coupled to 130.

The sleeve 140 has a smaller diameter portion 142 coupled to one end of the valve body 120 and a larger diameter than the small diameter portion 142 and is coupled to the valve housing 130 so as to be relatively movable. It is comprised by the neck part 143.

In addition, a sleeve bore 119 is formed in the valve housing 110 in which the large diameter portion 143 of the sleeve 140 is installed.

In addition, the small diameter portion 142 of the sleeve 140 may be press-fit or screwed into one end of the valve body 120. To this end, although the small diameter portion 142 of the sleeve 140 has a two-stage structure having a different diameter, it may be formed in a single-stage structure having a single diameter.

According to the coupling structure of the sleeve 140 and the valve body 120, the valve body 120 is first assembled to the valve housing 130, and then the small diameter portion of the sleeve 140 at one end of the valve body 120 ( 142 may be press-fitted, and the diameter of the large-diameter portion 143 which is relatively moved relative to the valve housing 130 may not be changed during the actual press-in, so that the pressure between the discharge pressure Pd working space and the suction pressure Ps working space is not changed. Sealing can be secured.

On the other hand, the cross-sectional area (Ac) with respect to the diameter of the large diameter portion of the sleeve 140 is the cross-sectional area (Ad) of the diameter of the first guide hole 117 and the cross-sectional area (Aa) of the diameter of the valve body 120 It is preferable that the sum is greater than or equal to 2 divided by 2, which will be described later.

In addition, the cross-sectional area Ac of the large diameter part diameter of the sleeve 140 may be the same as the cross-sectional area Aa of the diameter of the valve body 120.

In addition, the solenoid 130 is a movable iron core 131 connected to the valve body 120, an electromagnetic coil 132 disposed around the movable iron core 131, the electromagnetic coil 132, and the like. Wrapping is composed of a solenoid housing 134 and a fixing iron core 133 wrapped around the valve body 120 and disposed inside the electromagnetic coil 132.

The solenoid housing 134 corresponds to an injection molded product or an insulating case surrounding the electronic coil 132.

Accordingly, the movable iron core 131 and the valve body 120 reciprocate by the energization of the electromagnetic solenoid 130, and the discharge chamber connecting hole 113 and the crank by one end of the valve body 120. The inlet of the first guide hole 117 connecting the thread connecting hole 112 is opened and closed.

In addition, an off-spring 125 is provided between the fixed iron core 133 and the movable iron core 131 or between the fixed iron core 133 and the valve body 120, so that there is no external force in a normal valve body ( 120 rises to maintain the inlet of the first guide hole 117 is open.

In addition, the solenoid 130 is provided with a core 135, and a stopper 136 corresponding to an end of the movable iron core 131 is formed at a lower end of the core 135 to maximize the valve body 120. Limit the amount of opening.

A bellows accommodating portion 170 is formed at an end of the valve housing 110 opposite to the solenoid 130 of the valve housing 110. A portion of the tip of the sleeve 140 passing through the sleeve bore 119 of the valve housing 110 protrudes from the bellows accommodating part 170, and a bellows 160 is provided at the tip thereof.

The bellows 160 is a corrugated structure in which a certain amount of air is filled so that a predetermined pressure is applied when no external load is applied, and the bellows 160 exerts a force on a component connected thereto while performing expansion / contraction by external pressure. Component.

In addition, a coupling hole 141 is formed in the sleeve 140, and a coupling hole 161 is formed in the bellows 160 to be firmly fixed to each other.

In addition, a spring 162 may be built in the bellows 160 to maintain an expanded state.

In addition, the support spring 163 is connected between the bellows 160 and the valve housing 110, so that the bottom of the bellows 160 is always supported outward. As a result, the expansion force of the bellows 160 and the expansion force of the spring 162 installed therein are regulated.

On the other hand, the bellows receiving portion 170 is directly connected to the suction chamber 22, the suction chamber pressure (Ps) is applied. However, the suction chamber 22 and the bellows receiving unit 170 may be connected through a separate inlet (not shown) formed in the compressor housing.

In addition, a cap 165 is further provided to surround the bellows 160, and the cap 165 is screwed with the valve housing 110 to rotate the bellows 160 by the rotation of the cap 165. The initial set value of the spring 162 can be adjusted.

 On the other hand, the cap 165 is formed so that a part is open so that the pressure (Ps) of the suction chamber 22 acts, the opening of the cap 165 is provided with a filter (not shown) to the control valve It is desirable to play a role to block the introduction of foreign matter.

In addition, although not shown, the lower end of the solenoid housing 134 in which the movable iron core 131 is installed is preferably configured to communicate the pressure Pc of the crank chamber 86.

As a result, the pressure Pc of the crank chamber 86 can be applied to one end of the valve body 120.

Furthermore, the suction solenoid gas having the pressure Pc of the crank chamber 86 passes through the solenoid housing 134 so that the electronic solenoid 130 portion can be effectively cooled. Accordingly, the reliability of the electronic solenoid 130 is increased, and the electronic solenoid 130 can accurately generate electromagnetic force proportional to the current without being affected by the generated heat.

Hereinafter, the operation of the capacity control valve according to the present invention with reference to the drawings.

In the operation description, the initial state is a state in which power supply to the capacity control valve 100 is cut off, and the valve body 120 is lowered by the off-spring 125 so that one end of the valve body 120 is connected to the discharge chamber. The first guide hole 117 connecting between the 113 and the crankcase connecting hole 112 is separated from the inlet to maintain an open state.

Accordingly, since the discharge pressure Pd acts on the crank chamber 86 through the crank chamber connecting hole 112 via the first guide hole 117 through the discharge chamber connecting hole 113, the crank chamber 86 ), The pressure increases and the inclination angle of the swash plate 50 rapidly decreases, thereby reducing the amount of refrigerant discharged.

Next, when the engine speed, the indoor and outdoor temperature difference, the evaporator downstream temperature and pressure is detected and the signal is sent to the MCU, the calculation is performed with the thermal load set in the MCU, and the detected thermal load exceeds the set value. The current signal for increasing the refrigerant discharge amount is sent to the power source.

Accordingly, the electric current flows through the solenoid 130 so that the movable core 131 and the valve body 120 overcome the resistance of the off-spring 125 and the discharge pressure Pd of the discharge chamber connecting hole 113. By moving upward, the discharge chamber connecting hole 113 is closed.

As a result, the pressure inside the crank chamber 86 decreases and the inclination angle of the swash plate 50 increases, so that the discharge amount and the discharge pressure of the compressor increase rapidly.

At this time, the suction pressure Ps is increased due to the external thermal load, that is, the indoor temperature is high, and the suction pressure Ps thus raised is applied to the bellows receiving unit 170 through the filter 162. do.

The bellows 160 is reduced by the increased suction pressure Ps, and the valve body 120 fixed to the bellows 160 receives a rising force. In such a relationship, the valve body 120 can be easily moved up and down even if the electric current acting on the electromagnetic solenoid 130 is small. When the amount of current acting on the electronic solenoid 130 decreases, the amount of heat generated from the electronic coil 132 also decreases, thereby minimizing the thermal effect of the electronic solenoid 130 and maintaining reliability.

On the contrary, when the thermal load is reduced, a signal for the reduced current from the MCU is transmitted to the electronic solenoid 130, and in this case, the electromagnetic force is also reduced, so that the valve body (B) is discharged by the force of the discharge pressure Pd and the off spring 125. 120) receives a descending force.

Accordingly, one end of the valve body 120 starts to be separated from the inlet of the first guide hole 117 connecting between the discharge chamber connecting hole 113 and the crank chamber connecting hole 112, and then the discharge pressure ( Since Pd) acts on the crank chamber 86, the pressure of the crank chamber 86 is increased, and the inclination angle of the swash plate 50 and the discharge amount of the refrigerant are also drastically reduced.

In this state, since the cooling of the room temperature has already been sufficiently achieved, since the suction pressure Ps is naturally reduced, the bellows 160 expands again to assist the lowering of the valve body 120.

On the other hand, the displacement control valve 100 of the present invention described above is formed so that the discharge pressure (Pd) acts on one end of the valve body (120).

For example, the cross-sectional area Ab of the diameter of the small diameter portion 142 of the sleeve 140 is the diameter of the first guide hole 117 to facilitate the valve assembly and the discharge pressure Pd to move to the crank chamber 86. It is formed smaller than the cross-sectional area (Ad) for, the cross-sectional area (Aa) for the diameter of the valve body 120 is larger than the cross-sectional area (Ad) of the first guide hole 117 to open and close the first guide hole (117) It is formed large (Ab <Ad <Aa).

Here, the valve body 120 may be assumed to have a balance of force (valve closing direction = valve opening direction), and therefore, the valve body 120 is caused by the discharge pressure Pd acting on the valve body 120. ) Moves in the open direction.

Therefore, if the current value supplied to the electromagnetic solenoid 130 is made constant, as the discharge pressure Pd increases, the crank chamber outlet pressure Pc and the suction pressure Ps (in use of the compressor, the crank chamber 86). Pressure (Pc) and suction pressure (Ps) are approximately equal), and the sleeve 140 of the present invention has been proposed to improve this.

Specifically, the cross-sectional area Ac of the large diameter portion 143 of the sleeve 140 is the sum of the cross-sectional area Ad of the first guide hole 117 and the cross-sectional area Aa of the valve body 120 equal to two. The discharge pressure Pd applied to one end of the valve body 120 by forming a value greater than or equal to the divided value also acts on the large diameter portion 143 of the sleeve 140 so that the valve body 120 It remains stationary without movement by equilibrium.

As a result, since the valve body 120 is not opened by the discharge pressure Pd, the suction pressure Ps is maintained at a constant value so that the control precision of the capacity control valve 100 according to the present invention is improved.

As shown in Fig. 6, in the displacement control valve of the present invention described above, the force equilibrium relationship between the components is as follows.

ΣF = Pc * Aa - Pd * ( Ad - Ab ) - ( Pc + Pd ) * ( Aa - Ad ) / 2 + Pd *

        ① ② ③

(Ac-Ab) -Ps * Ac + F_bellows - Fs_1 + Fs_2 - Fs_3 + F_ solenoid

    ④ ⑤ ⑥ ⑦ ⑧ ⑨ ⑩

That is, ΣF = ½Pc * (Aa + Ad) + ½Pd * (2Ac-Ad-Aa)-Ps * Ac + (⑥, ⑦, ⑧, ⑨, ⑩)

Here, Aa: (π / 4) * a ² , that is, the cross-sectional area for the diameter a, so Ab, Ac, Ad are the cross-sections for the respective diameters b, c, d, and Fs: Spring Force of ⑦, ⑧, ⑨ , ⑥'s F_bellows: Bellows Force (function of Ps), ⑩'s F_solenoid: meaning electromagnetic force.

As a result, in order to avoid a phenomenon in which the suction pressure Ps increases as the discharge pressure Pd increases, the valve body 120 should not be forced in the direction in which the valve body 120 opens when the discharge pressure Pd increases.

As described above, since (2Ac-Ad-Aa) ≥ 0, that is, Ac ≥ (Ad + Aa) / 2 is satisfied, the discharge pressure Pd does not act in the opening direction (-direction of F) of the valve body 120. Since the discharge pressure Pd is increased, the suction pressure Ps is maintained at a constant value so that control can be easily performed.

In the above-described action of the present invention, one end of the valve body 120 is shown only to open and close the inlet, but the opening degree of the inlet of the first guide hole 117 can be adjusted according to the amount of energization. Of course.

1 is a longitudinal sectional view showing a capacity control valve of a variable displacement compressor according to the prior art.

2 is an enlarged longitudinal sectional view (a) and an operation explanatory view (b) of an essential part of a capacity control valve according to the prior art.

3 is a graph showing Pd-Ps characteristics of the displacement control valve of FIG.

4 is a longitudinal sectional view showing the structure of a variable displacement compressor according to the present invention.

FIG. 5 is a longitudinal sectional view showing the structure of the displacement control valve in FIG. 4. FIG.

FIG. 6 is a longitudinal cross-sectional view showing a balance of forces between components in the displacement control valve of FIG. 4.

7 is a longitudinal sectional view showing a coupling structure of a valve body and a sleeve in FIG.

* Description of symbols on main parts of the drawings *

100 ... Capacity control valve

110 ... valve housing

112. Crankcase connector

113.Discharge chamber connection

117 ... The first guide

119 ... Sleeve Bore

120 ... valve body

130 ... electronic solenoid

131. Iron core

132 ... electromagnetic coil

134 ... solenoid housing

137 ... The Second Guide

140 ... sleeve

142 ... small diameter of sleeve

143. Large diameter of sleeve

160 ... bellows

170 ... bellows receptacle

C ... variable displacement compressor

Claims (9)

In the displacement control valve of the variable displacement compressor, A valve housing formed with a crank chamber connecting hole and a discharge chamber connecting hole respectively receiving a crank chamber pressure and a discharge chamber pressure of the compressor, and a first guide hole passing through the discharge chamber connecting hole and the crank chamber connecting hole respectively; A valve body configured to open and close an inlet of the first guide hole while one end thereof reciprocates toward the inlet of the first guide hole; An electromagnetic solenoid for reciprocating the valve body by energization; And A sleeve coupled to one end of the valve body, the sleeve penetrating the first guide hole and coupled to the valve housing so as to be movable relative to the valve housing, The sleeve includes a small diameter portion coupled to one end of the valve body and a large diameter portion larger in diameter than the small diameter portion and coupled to the valve housing to allow relative movement. The large diameter section of the sleeve is, And the sum of the cross-sectional area of the first guide hole and the cross-sectional area of the valve body is greater than or equal to 2 divided by two. In the displacement control valve of the variable displacement compressor, A valve housing formed with a crank chamber connecting hole and a discharge chamber connecting hole respectively receiving a crank chamber pressure and a discharge chamber pressure of the compressor, and a first guide hole passing through the discharge chamber connecting hole and the crank chamber connecting hole respectively; A valve body configured to open and close an inlet of the first guide hole while one end thereof reciprocates toward the inlet of the first guide hole; An electromagnetic solenoid for reciprocating the valve body by energization; And A sleeve coupled to one end of the valve body, the sleeve penetrating the first guide hole and coupled to the valve housing so as to be movable relative to the valve housing, The sleeve includes a small diameter portion coupled to one end of the valve body and a large diameter portion larger in diameter than the small diameter portion and coupled to the valve housing to allow relative movement. A large diameter cross-sectional area of the sleeve is the same as the cross-sectional area of the valve body capacity control valve of the variable displacement compressor. The method according to claim 1 or 2, The small diameter portion of the sleeve is a capacity control valve of a variable displacement compressor, characterized in that the press-fit or screwed to one end of the valve body. The method according to claim 1 or 2, Capacity control valve of the variable displacement compressor, characterized in that the bellows is further provided at the end of the large diameter portion of the sleeve. 5. The method of claim 4, The bellows capacity control valve of the variable displacement compressor, characterized in that the fixed coupling with the sleeve to prevent relative movement. The method of claim 5, Capacitance control valve of the variable displacement compressor, characterized in that the cap is coupled to the valve housing so as to surround the bellows. The method of claim 6, A capacity control valve of a variable displacement compressor, characterized in that a support spring is provided between the bellows and the valve housing. delete delete

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