Variable-capacity compressor control valve

Provided is a variable-capacity compressor control valve that can suppress a decrease in the efficiency by reducing the amount of leakage in the valve without requiring severe accuracy of the components, avoid possible operation failures, and suppress the influence on the sliding resistance as well as the influence on the control characteristics. A main valve element of a valve element or a valve body is provided with a flexible or elastic sealing member. The sealing member is adapted to, when the valve orifice is closed by the main valve element, abut an end portion on the higher pressure side in a gap between sliding surfaces that is formed between the main valve element and a guide hole into which the main valve element is adapted to be slidably fitted and inserted, and thus seal the gap between the sliding surfaces.

CLAIM OF PRIORITY

The present application claims priority from Japanese patent application JP 2015-244966 filed on Dec. 16, 2015, the content of which is hereby incorporated by reference into this application.

BACKGROUND

Technical Field

The present invention relates to a variable-capacity compressor control valve for use in an automotive air conditioner or the like.

Background Art

Conventionally, a variable-capacity swash plate compressor such as the one schematically shown inFIG. 10has been used as a compressor for an automotive air conditioner. The variable-capacity swash plate compressor100includes a rotating shaft101that is rotationally driven by an on-vehicle engine, a swash plate102that is attached to the rotating shaft101, a crank chamber104in which the swash plate102is disposed, a piston105that is reciprocated by the swash plate102, a discharge chamber106for discharging refrigerant compressed by the piston105, a suction chamber107for sucking refrigerant, an in-compressor release passage (fixed orifice)108for releasing a pressure Pc in the crank chamber104to the suction chamber107, and the like.

Meanwhile, a control valve1′ used for the aforementioned variable-capacity compressor receives the discharge pressure Pd from the discharge chamber106of the compressor100and is configured to control the pressure Pc in the crank chamber104by controlling the discharge pressure Pd in accordance with the suction pressure Ps of the compressor100. Such a control valve1′ has, as the basic configuration, a valve body that includes a valve chamber with a valve orifice, a Ps introduction port communicating with the suction chamber107of the compressor100, a Pd introduction port arranged upstream of the valve orifice and communicating with the discharge chamber106of the compressor100, and a Pc outlet port arranged downstream of the valve orifice and communicating with the crank chamber104of the compressor100; a valve element (valve stem) for opening or closing the valve orifice; an electromagnetic actuator with a plunger for moving the valve element in the direction to open or close the valve orifice (in the vertical direction); a pressure-sensitive chamber that receives the suction pressure Ps from the compressor100via the Ps introduction port; and a pressure-sensitive reaction member that urges the valve element in the direction to open or close the valve orifice in accordance with the pressure in the pressure-sensitive chamber. The valve element and the valve orifice form a valve unit indicated by reference numeral11′ inFIG. 10(for example, see Patent Document 1 below).

In the control valve1′ with such a configuration, when current is flowed through a solenoid portion including a coil, a stator, an attractor, and the like of the electromagnetic actuator, the plunger is attracted by the attractor, and along with this, the valve element is moved in the direction to close the valve such that it follows the plunger by the urging force of a valve closing spring. Meanwhile, the suction pressure Ps introduced from the compressor100via the Ps introduction port is introduced into the pressure-sensitive chamber from an inlet/outlet chamber via a gap formed between the plunger and a guide pipe arranged around the outer periphery of the plunger or the like. Then, the pressure-sensitive reaction member (e.g., a bellows device) is expansively or contractively displaced in accordance with the pressure (suction pressure Ps) in the pressure-sensitive chamber (contracts if the suction pressure Ps is high, and expands if it is low), and the displacement (urging force) is then transmitted to the valve element, whereby the valve element portion of the valve element moves up or down with respect to the valve orifice to regulate the valve opening of the valve unit11′. That is, the valve opening is determined by the force of attracting the plunger with the solenoid portion, the urging force (expansion or contraction force) that acts with the expansive or contractive displacement of the pressure-sensitive reaction member, the urging force of a plunger spring (valve opening spring) and the valve closing spring. The pressure Pc in the crank chamber104(hereinafter also referred to as a crank chamber pressure Pc or simply referred to as a pressure Pc) is controlled in accordance with the valve opening.

In response to the aforementioned variable-capacity compressor, an improved variable-capacity swash plate compressor, such as the one schematically shown inFIGS. 11A and 11B, for example, has already been proposed that is intended to reduce the time required to increase the discharge capacity at the compressor actuation time, and suppress or reduce a decrease in the operation efficiency of the compressor at the normal control time.

A control valve2′ used for such an improved variable-capacity swash plate compressor200has a valve element (valve stem) including a main valve element and a sub valve element, and has an in-valve release passage16′ in the main valve element. The control valve2′ basically has a valve body that includes a valve chamber with a valve orifice, a Ps inlet/outlet port communicating with a suction chamber107of the compressor200, a Pd introduction port arranged upstream of the valve orifice and communicating with a discharge chamber106of the compressor200, and a Pc inlet/outlet port arranged downstream of the valve orifice and communicating with a crank chamber104of the compressor200; a main valve element for opening or closing the valve orifice; an electromagnetic actuator with a plunger for moving the main valve element in the direction to open or close the valve orifice; a pressure-sensitive chamber that receives the suction pressure Ps from the compressor200via the Ps inlet/outlet port; and a pressure-sensitive reaction member that urges the main valve element in the direction to open or close the valve orifice in accordance with the pressure in the pressure-sensitive chamber. Further, the in-valve release passage16′ for releasing the pressure Pc in the crank chamber104to the suction chamber107of the compressor200via the Ps inlet/outlet port is provided in the main valve element, and the sub valve element for opening or closing the in-valve release passage16′ is also provided so that when the plunger is continuously moved upward from the lowest position by the attraction force of the electromagnetic actuator, the sub valve element moves upward together with the plunger while closing the in-valve release passage16′, and the main valve element is also moved upward so as to follow the sub valve element. Then, after the valve orifice is closed by the main valve element, if the plunger is further moved upward, the sub valve element is configured to open the in-valve release passage16′. The main valve element and the valve orifice form a main valve unit indicated by reference numeral11′ inFIGS. 11A and 11B, while the sub valve element and the in-valve release passage form a sub valve unit indicated by reference numeral12′ (for example, see Patent Document 2 below).

At the normal control time (Pd→Pc control time) of the control valve2′ with such a configuration, when current is flowed through a solenoid portion including a coil, a stator, an attractor, and the like of the electromagnetic actuator, the plunger is attracted by the attractor, and along with this, the sub valve element moves upward integrally with the plunger, and following the movement of the sub valve element, the main valve element is moved in the direction to close the valve by the urging force of a valve closing spring. Meanwhile, the suction pressure Ps introduced from the compressor200via the Ps inlet/outlet port is introduced into the pressure-sensitive chamber from an inlet/outlet chamber via a horizontal hole in the plunger or the like, and the pressure-sensitive reaction member (e.g., a bellows device) is expansively or contractively displaced in accordance with the pressure (suction pressure Ps) in the pressure-sensitive chamber (contracts if the suction pressure Ps is high, and expands if it is low), and the displacement (urging force) is then transmitted to the main valve element, whereby the main valve element portion of the main valve element moves up or down with respect to the valve orifice to regulate the valve opening of the main valve unit11′. That is, the valve opening is determined by the force of attracting the plunger with the solenoid portion, the urging force (expansion or contraction force) that acts with the expansive or contractive displacement of the pressure-sensitive reaction member, the urging force of a plunger spring (valve opening spring) and the valve closing spring, and force that acts on the main valve element in the valve opening direction and in the valve closing direction. The pressure Pc in the crank chamber104is controlled in accordance with the valve opening. In such a case, the main valve element is always urged upward by the urging force of the valve closing spring, while the sub valve element is always urged downward by the urging force of the valve opening spring. Thus, the sub valve unit12′ is closed and the in-valve release passage16′ is blocked in the main valve element. Therefore, there is no possibility that the crank chamber pressure Pc may be released to the suction chamber107via the in-valve release passage16′.

In contrast, at the compressor actuation time, current is flowed through the solenoid portion so that the plunger is attracted by the attractor and the sub valve element moves upward together with the plunger. Following the upward movement of the sub valve element, the main valve element is moved in the direction to close the valve by the urging force of the valve closing spring, and after the valve orifice is closed by the main valve element portion of the main valve element, the plunger is further moved upward, whereby the sub valve element opens the in-valve release passage16′. Then, the crank chamber pressure Pc is released to the suction chamber107via two passages that are an in-compressor release passage108and the in-valve release passage16′ (for details, see Patent Document 2 below and the like).

RELATED ART DOCUMENTS

Patent Documents

Patent Document 1: JP 2010-185285 A

Patent Document 2: JP 2013-130126 A

Patent Document 3: JP 2011-043102 A

SUMMARY

By the way, in a variety of types of variable-capacity compressor control valves descried above, it is desired to reduce the amount of leakage in the valve by sealing a gap (clearance) between sliding surfaces that is formed between a valve element (or the outer peripheral surface thereof) and a guide hole (or the inner wall surface thereof) into which the valve element is adapted to be slidably fitted and inserted, and avoid a circumstance in which the gap (clearance) between the sliding surfaces is clogged with foreign matter, which would stop the motion of the valve element (operation failures such as a locked valve or a valve element that is left behind). In response to such a demand, it has been proposed to dispose a sealing member (O-ring), which is formed of a flexible annular body and adapted to be arranged around a valve element, between the valve element and the guide hole (for example, see Patent Document 3 above).

However, when a sealing member such as an O-ring is disposed between a valve element and a guide hole, there have been problems in that the accuracy of the components should be increased to suppress the sliding resistance, or the sliding resistance will change due to the deformation of the sealing member in accordance with the pressure difference (for example, if the pressure difference becomes large, the sealing member will greatly deform, which in turn will increase the sliding resistance), and further, the control characteristics will deteriorate (hysteresis will increase).

The present invention has been made in view of the foregoing, and it is an object of the present invention to provide a variable-capacity compressor control valve that can suppress a decrease in the efficiency by reducing the amount of leakage in the valve without requiring severe accuracy of the components, avoid possible operation failures, and suppress the influence on the sliding resistance as well as the influence on the control characteristics.

In order to achieve the aforementioned object, a variable-capacity compressor control valve in accordance with the present invention basically includes a valve body including a valve chamber with a valve orifice, a Ps inlet/outlet port communicating with a suction chamber of a compressor, a Pd introduction port arranged upstream of the valve orifice and communicating with a discharge chamber of the compressor, and a Pc inlet/outlet port arranged downstream of the valve orifice and communicating with a crank chamber of the compressor; a valve element adapted to open or close the valve orifice; an electromagnetic actuator with a plunger for moving the valve element in a direction to open or close the valve orifice; a pressure-sensitive chamber adapted to receive a suction pressure Ps from the compressor via the Ps inlet/outlet port; and a pressure-sensitive reaction member adapted to urge the valve element in the direction to open or close the valve orifice in accordance with a pressure in the pressure-sensitive chamber. The valve element is adapted to be slidably fitted and inserted into a guide hole provided in the valve body, and one of the valve element or the valve body is provided with a flexible or elastic sealing member, the sealing member being adapted to, when the valve orifice is closed by the valve element, abut an end portion on a higher pressure side in a gap between sliding surfaces that is formed between the valve element and the guide hole, and thus seal the gap between the sliding surfaces.

In a preferred aspect, the sealing member is disposed in an annular groove, the annular groove being provided around an outer periphery of the valve element.

In a further preferred aspect, the sealing member has a ring shape in which an inner peripheral portion of the sealing member is embedded in the annular groove and an outer peripheral portion of the sealing member protrudes from the annular groove.

The sealing member preferably has at least one cut-in formed in its inner peripheral portion.

The sealing member preferably has a partially cut-off portion in its circumferential direction.

In another preferred aspect, the sealing member is vertically movably disposed in the annular groove.

In still another preferred aspect, the sealing member is disposed on the valve body.

In a further preferred aspect, the sealing member has a ring shape in which an inner peripheral portion of the sealing member is embedded in the annular groove that is provided around the outer periphery of the valve element, and an outer peripheral portion of the sealing member is attached to the valve body.

The sealing member preferably has at least one cut-in formed in its inner peripheral portion.

The sealing member preferably has a partially cut-off portion in its circumferential direction.

In another preferred aspect, the sealing member is fixed to the valve body or is vertically movably disposed on the valve body.

In still another preferred aspect, the end portion on the higher pressure side in the gap between the sliding surfaces has a planar portion, and the sealing member is adapted to abut the planar portion.

In further another preferred aspect, the sealing member is adapted to be separated from the end portion on the higher pressure side in the gap between the sliding surfaces when the valve orifice is open.

In yet another preferred aspect, the valve element includes a main valve element and a sub valve element, the main valve element being adapted to open or close the valve orifice and having formed therein an in-valve release passage for releasing a pressure Pc in the crank chamber to the suction chamber of the compressor via the Ps inlet/outlet port, and the sub valve element being adapted to open or close the in-valve release passage. The sealing member is disposed on one of the valve body or the main valve element that is adapted to be fitted and inserted into the guide hole.

According to the variable-capacity compressor control valve in accordance with the present invention, a valve element or a valve body is provided with a flexible or elastic sealing member that is adapted to, when a valve orifice is closed by the valve element, abut an end portion on the higher pressure side in a gap between sliding surfaces that is formed between the valve element and a guide hole into which the valve element is adapted to be slidably fitted and inserted, and thus seal the gap between the sliding surfaces. Therefore, in comparison with the conventional art in which a sealing member such as an O-ring is disposed between a valve element and a guide hole, it is possible to suppress a decrease in the efficiency by reducing the amount of leakage in the valve without requiring severe accuracy of the components, avoid possible operation failures, such as a locked valve or a valve element that is left behind, and suppress the influence on the sliding resistance as well as the influence on the control characteristics.

DETAILED DESCRIPTION

First Embodiment

FIGS. 1 to 3are longitudinal sectional views each showing the first embodiment of the variable-capacity compressor control valve in accordance with the present invention. Specifically,FIG. 1is a view in which the main valve element is in the open position and the sub valve element is in the closed position (at the normal control time),FIG. 2is a view in which the main valve element is in the closed position and the sub valve element is in the closed position (at the time of transition to compressor actuation), andFIG. 3is a view in which the main valve element is in the closed position and the sub valve element is in the open position (at the compressor actuation time).

It should be noted that in the present specification, descriptions indicating the positions or directions, such as upper, lower, top, bottom, left, right, front, and rear, are used for the sake of convenience in accordance with the drawings to avoid complexity in the description, but such descriptions do not necessarily indicate the actual positions or directions when the control valve of the present invention is incorporated into a compressor.

In addition, in each drawing, a gap formed between members, a clearance between members, and the like may be depicted larger or smaller than their actual dimensions to help understand the present invention and also for the sake of convenience to create the drawing.

A control valve1in the shown embodiment has a valve body20with a valve orifice22; a valve element10with a main valve element15for opening or closing the valve orifice22; an electromagnetic actuator30for moving the valve element10(main valve element15) in the direction to open or close the valve orifice (in the vertical direction); and a bellows device40that serves as a pressure-sensitive reaction member.

The electromagnetic actuator30includes a bobbin38, an energization coil32wound around the bobbin38, a connector head31attached to the upper side of the bobbin38with an attachment plate39interposed therebetween, a stator33and an attractor34arranged on the inner peripheral side of the coil32, a guide pipe35whose upper end portion is joined by welding to the outer periphery of the lower end portion (a step portion) of the stator33and the attractor34, a plunger37having a recessed cross section and arranged vertically slidably on the inner peripheral side of the guide pipe35below the attractor34, a cylindrical housing60externally arranged around the coil32, and a holder29arranged between the lower end portion of the housing60and the guide pipe35and adapted to fix them to the top of the valve body20. In the present example, the attractor34with a recessed cross section is integrally molded with the inner periphery of the bottom of the cylindrical stator33. Herein, a portion of the electromagnetic actuator30including the coil32, the stator33, the attractor34, and the like and excluding the plunger37is referred to as a solenoid portion30A.

A stator65in a short columnar shape is attached to the top of the stator33by press fitting or the like, and a pressure-sensitive chamber45, which receives a suction pressure Ps in a compressor100, is formed between the stator65and the attractor34on the inner peripheral side of the stator33. The pressure-sensitive chamber45has arranged therein the bellows device40that serves as a pressure-sensitive reaction member and includes bellows41, an upper stopper42in an inverted projection shape, a lower stopper43in an inverted recessed shape, and a compression coil spring44. Further, a top small-diameter portion17d(an end portion on the side opposite to a sub valve element portion17a) of a sub valve element17described below is fitted and inserted in and supported by the recess of the lower stopper43, and a compression coil spring46, which urges the bellows device40in the direction to contract the bellows device40, is provided in a compressed state between the lower stopper43and the attractor34.

The plunger37has a cylindrical upper half portion37A and a columnar lower half portion37B. Provided in the center of the columnar lower half portion37B is an insertion hole37bthrough which a waist portion17bof the sub valve element17that extends downward through the attractor34and a top small-diameter portion15f(described in detail below) of the main valve element15are inserted. The outer peripheral portion of the insertion hole37bon the upper surface of the columnar lower half portion37B serves as a latch portion37ato which an intermediate large-diameter latch portion17cof the sub valve element17is latched.

In addition, a plunger spring (valve opening spring)47constructed from a cylindrical compression coil spring, which urges the sub valve element17and the plunger37downward (in the direction to open the valve), is provided in a compressed state between the attractor34and the intermediate large-diameter latch portion17cof the sub valve element17(plunger37) so that the sub valve element17(or the intermediate large-diameter latch portion17cthereof) is pressed against the plunger37by the plunger spring47and thus is caused to move up or down with the plunger37.

Further, as can be understood well fromFIGS. 4A to 4E, the bottom of the columnar lower half portion37B of the plunger37(a portion that is above the lower end portion by a predetermined distance) has a cut-in37twith an approximately semicircular shape in plan view (in the horizontal direction) that is formed so as to overlap the insertion hole37b. On the side below the cut-in37t(i.e., at a portion between the cut-in37tand the lower end portion of the columnar lower half portion37B), a slit37swith approximately the same width as the hole diameter of the insertion hole37bis formed that extends linearly from the edge portion at the lower end of the columnar lower half portion37B to the insertion hole37b. The height (in the vertical direction) of the cut-in37tis slightly larger than the height of a flanged latch portion15kof the main valve element15, and the height (in the vertical direction) of the slit37sis slightly smaller than the height of the top small-diameter portion15fof the main valve element15. The main valve element15is movable in the vertical direction with respect to the plunger37(which will be described in detail below). The width (in the horizontal direction) of the slit37sis set slightly larger than the outside diameter of the top small-diameter portion15fof the main valve element15and smaller than the outside diameter of the flanged latch portion15kof the main valve element15taking into consideration the assembling properties and the like.

The valve element10has the main valve element15and the sub valve element17arranged in the vertical direction (along the direction of the axial line O).

The main valve element15arranged on the lower side has, sequentially arranged from the bottom side, a bottom fit-insertion portion15b, a lower small-diameter portion15c, a main valve element portion15a, an intermediate small-diameter portion15d, a top fit-insertion portion15e, the top small-diameter portion15f, and the flanged latch portion15k. A stepped release through-hole16A forming part of an in-valve release passage16is provided in the center of the main valve element15such that it penetrates the center of the main valve element15in the vertical direction, and the upper end portion of the release through-hole16A serves as a sub valve seat portion23with/from which the lower end portion (sub valve element portion)17aof the sub valve element17is moved into contact or away. The intermediate small-diameter portion15dof the main valve element15has a plurality of horizontal holes16s.

The top small-diameter portion15fof the main valve element15is loosely fitted in the insertion hole37b(or a portion below the cut-in37tthereof), and the flanged latch portion15kof the main valve element15has a larger diameter than that of the insertion hole37bso that when the plunger37is moved upward with respect to the main valve element15, the flanged latch portion15kis lathed to an inner flanged latch portion37kthat is formed by the outer peripheral portion of the insertion hole37b, and thus, latching is achieved and slippage is prevented.

In addition, an annular groove15hwith a predetermined width in the vertical direction is provided around the outer periphery of the upper end of the bottom fit-insertion portion15b(or the outer periphery of the lower end of the lower small-diameter portion15c) of the main valve element15, and a sealing member (packing)14in a thin ring shape produced from a flexible material or an elastic material, such as Teflon (registered trademark) or rubber, is vertically movably disposed in the annular groove15h.

In the present example, the annular groove15his formed such that when the valve orifice22is in the fully open state (when the main valve element15is at the lowest position, seeFIG. 1), an upper surface15haof the annular groove15his located above the bottom surface (planar portion) of the reception hole18of the valve body20by an amount corresponding to the thickness of the sealing member14, and when the valve orifice22is closed (when the main valve element15is at the highest elevated position, seeFIGS. 2 and 3), a lower surface15hbof the annular groove15his substantially flush with the bottom surface (planar portion) of the reception hole18. In addition, the flexible or elastic sealing member14is disposed in the annular groove15hsuch that the inner peripheral portion thereof is embedded in the annular groove15hand the outer peripheral portion thereof protrudes from the annular groove15h.

Herein, the scaling member14may be provided with, taking into consideration the attachability thereof to the main valve element15(or the annular groove15hthereof), at least one cut-in14aformed in its inner peripheral portion as shown inFIG. 5A, for example (four equiangular cut-ins14ain the shown example), or a partially cut-off portion (point) formed in its circumferential direction (a cut-off portion14b) as shown inFIG. 5B. Alternatively, when the sealing member14is produced from a material with relatively high elasticity such as rubber, for example, the cut-ins14aand the cut-off portion14bmay be omitted.

The sub valve element17arranged above the main valve element15has, sequentially arranged from the bottom side, an inverted conical tapered portion17a, which is moved into contact with or away from the sub valve seat portion23that is the edge portion at the upper end of the release through-hole16A, the waist portion17bhaving the intermediate large-diameter latch portion17cformed thereon, a truncated conical portion17e, and a top small-diameter portion17dthat is inserted in and supported by the recess of the lower stopper43. The tapered portion17aserves as the sub valve element portion that opens or closes the in-valve release passage16. Herein, the sub valve seat portion23and the sub valve element portion17aform the sub valve unit12. In the present example, a portion below the intermediate large-diameter latch portion17cof the waist portion17is inserted into the insertion hole37bof the plunger37with a small gap therebetween, and a portion above the intermediate large-diameter latch portion17cand below the attractor (a portion arranged inside the cylindrical upper half portion37A) has a slightly larger diameter than those of the other portions.

The dimensions and the shape of each part around the sub valve element17(e.g., a gap between the waist portion17band the insertion hole37b) are designed such that even when the sub valve element17is slightly tilted at a position where it has been moved upward with respect to the main valve element15(i.e., a position where the in-valve release passage16is open), the lower end portion of the sub valve element portion (a tapered portion)17ain an inverted conical shape enters the release through-hole16A, and the sub valve element17is thus aligned with the main valve element15by the sub valve element portion17aas the sub valve element17moves closer to the main valve element15(i.e., when the sub valve element17closes the in-valve release passage16). More specifically, the dimensions and the shape of each part are designed such that part of the sub valve element portion17ain an inverted conical shape is located in the release through-hole16A when the sub valve element17is at the highest elevated position with respect to the main valve element15(seeFIG. 3, in particular).

When the valve element10(the main valve element15and the sub valve element17) and the plunger37are assembled, for example, the main valve element15is moved horizontally with respect to the plunger37so that the flanged latch portion15kand the top small-diameter portion15fof the main valve element15, which has been assembled in advance to the valve body20(or a guide hole19thereof), are inserted into the cut-in37tand the slit37sof the plunger37, respectively, and the top small-diameter portion15fis fitted and inserted into the insertion hole37bprovided in the center of the plunger37, and thereafter, the sub valve element17(or a portion below the intermediate large-diameter latch portion17cthereof) may be inserted into the insertion hole37bfrom above.

Meanwhile, the valve body20has a two-split structure that includes a body member20A having a fit recess hole20C in the center at the top thereof, and a support member20B that is fixedly inserted into the recess hole20C by press fitting or the like.

The support member20B is produced from a material with relatively high hardness, such as stainless steel (SUS), and has a protruding stopper portion24A for defining the lowest position of the plunger37, on the upper side of a fit-insertion portion24that is fitted and inserted in the recess hole20C. In addition, the guide hole19(an upper guide hole19A) into which the top fit-insertion portion15eof the main valve element15is slidably fitted and inserted is formed in the center of the support member20B such that it penetrates the support member20B in the vertical direction, and the lower end portion of the upper guide hole19A serves as the valve orifice22(a valve seat portion) that is opened or closed by the main valve element portion15aof the main valve element15. Herein, the main valve element portion15aand the valve orifice22form a main valve unit11. As the support member20B is produced from a material with high hardness, such as stainless steel, as described above, the specific gravity of the support member20B is also high.

The body member20A is produced from a material, such as aluminum, brass, or resin, that has relatively low specific gravity (a material with relatively low hardness) as compared to stainless steel and the like. An inlet/outlet chamber28for the suction pressure Ps in the compressor100is formed around the outer periphery of the stopper portion24A, and a plurality of Ps inlet/outlet ports27are formed around the outer peripheral side of the inlet/outlet chamber28in a state in which the support member20B (or the fit-insertion portion24thereof) is inserted in the recess hole20C of the body member20A. The suction pressure Ps introduced into the inlet/outlet chamber28from the Ps inlet/outlet ports27is introduced into the pressure-sensitive chamber45via the slit37sand the cut-in37tformed at the bottom of the plunger37, a gap formed between the waist portion17bof the sub valve element17and the insertion hole37bof the plunger37, a gap36formed between the outer periphery of the plunger37and the guide pipe35, and the like.

A reception hole18, which has a larger diameter than those of the guide hole19and the main valve element portion15aand has a smaller diameter than that of the recess hole20C and is adapted to store the main valve element portion15aof the main valve element15, is provided continuously with the center of the bottom of the recess hole20C of the body member20A, and the guide hole19(a lower guide hole19B) into which the bottom fit-insertion portion15bof the main valve element15is slidably fitted and inserted is formed in the center of the bottom of the reception hole18. A valve closing spring50constructed form a conical compression coil spring is provided in a compressed state between the corner on the outer periphery of the bottom of the reception hole18and a stepped portion (terrace portion)15gprovided on the outer periphery of the bottom of the main valve element portion15aof the main valve element15. Thus, with the urging force of the valve closing spring50, the main valve element15(or a step portion between the top fit-insertion portion15eand the top small-diameter portion15fthereof) is pressed against the plunger37.

The inside of the reception hole18(a portion below the valve orifice22of the support member20B) is the valve chamber21. The valve chamber21has a plurality of Pd introduction ports25communicating with a discharge chamber106of the compressor100. A ring-like filter member25A is arranged around the outer periphery of the Pd introduction ports25of the body member20A.

The lower end portion of the body member20A has a lid-like member48, which functions as a filter, fixed thereto by engagement, press fitting, or the like. A Pc inlet/outlet chamber (inlet/outlet port)26, which communicates with a crank chamber104of the compressor100, is provided on the side above the lid-like member48below the main valve element15. The Pc inlet/outlet chamber (inlet/outlet port)26communicates with the Pd introduction ports25via the release through-hole16A→the horizontal holes16s→a gap between the bottom of the upper guide hole19A and the intermediate small-diameter portion15d→a gap between the valve orifice22and the main valve element portion15a→the valve chamber21.

In addition, in this embodiment, the in-valve release passage16for releasing the pressure Pc in the crank chamber104to a suction chamber107of the compressor100via the Ps inlet/outlet ports27is formed by the release through-hole16A formed in the main valve element15, the cut-in37tand the slit37sprovided in the plunger37, the inlet/outlet chamber28, and the like. The in-valve release passage16is adapted to be opened or closed as the sub valve element portion17aof the sub valve element17is moved into contact with or away from the sub valve seat portion23that is the upper end portion of the release through-hole16A of the main valve element15.

Herein, in the control valve1in this embodiment, when the plunger37, the main valve element15, and the sub valve element17are at the lowest position (when the bottom end surface of the plunger37abuts the stopper portion24A, the main valve unit11is in the fully open position, and the sub valve unit12is in the fully closed position) as shown inFIG. 1, the clearance in the vertical direction between the main valve element portion15aof the main valve element15and the valve orifice22(valve seat portion) is represented by a first lift amount Lv, and the clearance between the inner flanged latch portion37kof the plunger37and the flanged latch portion15kof the main valve element15is represented by a predetermined amount La. The maximum lift amount (second lift amount) Lp of the plunger37(the lift amount of from the lowest position to the highest position of the plunger37) corresponds to the first lift amount Lv+the predetermined amount La.

Next, the operation of the control valve1with the aforementioned configuration will be generally described.

At the normal control time (Pd→Pc control time), the lift amount of the plunger37is slightly greater than the first lift amount Lv at the maximum, and at the compressor actuation time (Pc→Ps control time), the lift amount of the plunger37is the second lift amount Lp.

That is, at the normal control time (Pd→Pc control time), when the solenoid portion30A including the coil32, the stator33, the attractor34, and the like is supplied with current and energized, the plunger37is attracted by the attractor34, and along with this, the intermediate large-diameter latch portion17cof the sub valve element17is latched to the latch portion37aof the plunger37. Thus, the sub valve element17moves upward integrally with the plunger37, and following the movement of the sub valve element17, the main valve element15is moved upward (in the direction to close the valve) by the urging force of the valve closing spring50. Meanwhile, the suction pressure Ps introduced into the Ps inlet/outlet ports27from the compressor100is introduced into the pressure-sensitive chamber45from the inlet/outlet chamber28via the slit37sand the cut-in37tof the plunger37and the like, and the bellows device40(the inside thereof is at a vacuum pressure) is expansively or contractively displaced in accordance with the pressure (suction pressure Ps) in the pressure-sensitive chamber45(contracts if the suction pressure Ps is high, and expands if it is low), and the displacement is then transmitted to the main valve element15via the plunger37and the sub valve element17, whereby the valve opening (the clearance between the valve orifice22and the main valve element portion15a) is regulated, and the pressure Pc in the crank chamber104is controlled in accordance with the valve opening. Along with this, the inclination angle of the swash plate102and the stroke of the piston105in the compressor100are controlled to increase or decrease the discharge capacity.

In this case, the main valve element15is always urged upward by the urging force of the valve closing spring50, while the sub valve element17is always urged downward by the urging force of the valve opening spring47. Therefore, the sub valve element portion17ais in a state of being pressed against the sub valve seat portion23(the sub valve unit12is closed), and the in-valve release passage16is blocked in the main valve element15. Therefore, there is no possibility that the crank chamber pressure Pc may be released to the suction chamber107via the in-valve release passage16.

In contrast, at the compressor actuation time, the solenoid portion30A is supplied with current and energized, and the plunger37is attracted by the attractor34so that the sub valve element17moves upward together with the plunger37. Following such vertical movement of the sub valve element17, the main valve element15is also moved upward and the valve orifice22is closed by the main valve element portion15aof the main valve element15. After that, the plunger37is further moved upward, whereby the sub valve element17is caused to open the in-valve release passage16. Thus, the pressure Pc in the crank chamber104is released into the suction chamber107via two passages that are an in-compressor release passage108and the in-valve release passage16.

Specifically, until the upward movement amount of the plunger37reaches the first lift amount Lv, the main valve element15moves in the direction to close the valve such that it follows the upward movement of the plunger37and the sub valve element17by the urging force of the valve closing spring50. Then, when the upward movement amount reaches the first lift amount Lv, the valve orifice20is closed by the main valve element portion15aof the main valve element15(the state shown inFIG. 2), and the plunger37is further moved upward by the predetermined amount La with the main valve unit11in the closed valve state (the state shown inFIG. 3). In other words, after the upward movement amount of the plunger37has reached the first lift amount Lv, the sub valve element17is elevated by the predetermined amount La until the inner flanged latch portion37kof the plunger37is latched to the flanged latch portion15kof the main valve element15(the first lift amount Lv+the predetermined amount La=the second lift amount Lp). In such a case, the main valve element15remains still in the closed valve state. Thus, the sub valve element portion17aof the sub valve element17is lifted from the sub valve seat portion23by the predetermined amount La, whereby the in-valve release passage16is opened. When the inner flanged latch portion37kof the plunger37is latched to the flanged latch portion15kof the main valve element15, neither the plunger37nor the sub valve element17is lifted any further even if the solenoid portion30A generates an attraction force.

Herein, when the valve orifice20is closed by the main valve element portion15aof the main valve element15(the states shown inFIGS. 2 and 3), the inside of the reception hole18(the inside of the valve chamber21) communicating with the discharge chamber106of the compressor100via the Pd introduction ports25has a pressure higher than that in the Pc inlet/outlet chamber (inlet/outlet port)26communicating with the crank chamber104. Therefore, the sealing member14, which is vertically movably disposed in the annular groove15hof the main valve element15such that it is arranged in the valve chamber21, is pressed so as to be tightly in contact with an end portion on the valve chamber21side (higher pressure side) in a gap between sliding surfaces, which is formed between the bottom fit-insertion portion15b(or the outer peripheral surface thereof) of the main valve element15and the lower guide hole19B (or the inner peripheral surface thereof), due to the difference in pressure between the valve chamber21and the Pc inlet/outlet chamber (inlet/outlet port)26(herein, the outer peripheral portion of the sealing member14is made to abut the bottom surface (planar portion) of the reception hole18that forms the end portion on the valve chamber21side (higher pressure side) in the gap between the sliding surfaces). Thus, the sealing member14seals the gap between the sliding surfaces at a position between the valve chamber21and the Pc inlet/outlet chamber (inlet/outlet)26.

It should be noted that in the shown example, the dimensions and the shape of the annular groove15hof the main valve element15and the like are designed such that even when the valve orifice20is open (the state shown inFIG. 1), the sealing member14is made to abut the end portion on the valve chamber21side (higher pressure side) between the sliding surfaces. However, in such a state, it is not necessarily required to seal the end portion between the sliding surfaces because the Pd introduction ports25communicate with the Pc inlet/outlet chamber (inlet/outlet port)26via the valve chamber21→a gap between the valve orifice22and the main valve element portion15a→a gap between the bottom of the upper guide hole19A and the intermediate small-diameter portion15d→the horizontal holes16s→the release through-hole16A.

As described above, in the control valve1in this embodiment, the flexible or elastic sealing member14is disposed around the main valve element15of the valve element10. The sealing member14is adapted to, when the valve orifice22is closed by the main valve element15, abut an end portion on the higher pressure side in a gap between sliding surfaces, which is formed between the main valve element15(bottom fit-insertion portion15b) (or the outer peripheral surface thereof) and the guide hole19(lower guide hole19B) (or the inner peripheral surface thereof) into which the main valve element15is slidably fitted and inserted, and thus seal the gap between the sliding surfaces. Therefore, in comparison with the conventional art in which a sealing member such as an O-ring is disposed between a valve element and a guide hole, it is possible to suppress a decrease in the efficiency by reducing the amount of leakage in the valve without requiring severe accuracy of the components, avoid possible operation failures, such as a locked valve or a valve element that is left behind, and suppress the influence on the sliding resistance as well as the influence on the control characteristics.

It should be noted that the aforementioned sealing member (packing)14for sealing the gap between the sliding surfaces may also be disposed on the side of the valve body20(or the body member20A thereof) as shown inFIGS. 6A and 6B. In that case, the sealing member14is embedded at its inner peripheral portion in the annular groove15h(in the shown example, the outer peripheral portion of the lower small-diameter portion15cbetween the main valve element portion15aand the bottom fit-insertion portion15b) formed around the outer periphery of the valve element10(or the main valve element15thereof), while the sealing member14is attached at its outer peripheral portion to the valve body20(or the bottom surface of the reception hole18of the body member20A thereof). Herein, the sealing member14may be fixed to the valve body20by crimping or the like as in the shown example, or may be vertically movably disposed on the valve body20as in the aforementioned embodiment. In addition, even in such a case, the sealing member14may have at least one cut-in formed in its inner peripheral portion or a partially cut-off portion (point) formed in its circumferential direction as described above.

As described above, even if the flexible or elastic sealing member14is disposed on the valve body20, the sealing member14is adapted to abut an end portion on the higher pressure side in a gap between sliding surfaces, which is formed between the main valve element15(bottom fit-insertion portion15b) (or the outer peripheral surface thereof) and the guide hole19(lower guide hole19B) (or the inner peripheral surface thereof) into which the main valve element15is slidably fitted and inserted, and thus seal the gap between the sliding surfaces when the valve orifice22is closed by the main valve element15. Therefore, operational effects similar to those of the control valve1in the aforementioned embodiment can be obtained.

Second Embodiment

FIGS. 7A to 9are longitudinal sectional views each showing the second embodiment of the variable-capacity compressor control valve in accordance with the present invention. Specifically,FIGS. 7A-7Bare views in which the main valve element is in the open position and the sub valve element is in the closed position (at the normal control time);FIG. 8is a view in which the main valve element is in the closed position and the sub valve element is in the closed position (at the time of transition to compressor actuation), andFIG. 9is a view in which the main valve element is in the closed position and the sub valve element is in the open position (at the compressor actuation time).

The control valve2in the second embodiment basically differs from the control valve1in the aforementioned first embodiment only in the configurations of the valve body and the main valve element of the valve element. Thus, configurations with the same functions as those in the first embodiment are denoted by the same reference numerals and the detailed description thereof will thus be omitted. Hereinafter, only the differences will be discussed in detail.

In the control valve2in this embodiment, the top fit-insertion portion15eand the intermediate small-diameter portion15dof the main valve element15are formed longer than those of the control valve1in the first embodiment, while the lower small-diameter portion15cand the bottom fit-insertion portion15bon the lower side of the main valve element portion15aare omitted.

In addition, an annular groove15iis formed around the outer periphery of the upper end of the intermediate small-diameter portion15d(or the outer periphery of the lower end of the top fit-insertion portion15e) of the main valve element15, and a sealing member (packing)14similar to that in the first embodiment is disposed in the annular groove15isuch that it is vertically movable to some extent.

In the present example, the annular groove15iis formed such that when the valve orifice22is in the fully open state (when the main valve element15is at the lowest position, seeFIG. 1), a lower surface15ibof the annular groove15iis located above horizontal holes25s(which will be described in detail below) provided on the side of the lower small-diameter portion24bof the fit-insertion portion24of the support member20B of the valve body20, and when the valve orifice22is closed (when the main valve element15is at the highest elevated position, seeFIGS. 2 and 3), an upper planar surface15iaof the annular groove15iis substantially flush with the upper planar surface61(planar portion) of an inner peripheral groove24d(which will be described in detail below) provided around the inner periphery of the lower small-diameter portion24bof the fit-insertion portion24.

The fit-insertion portion24of the support member20B of the valve body20has a step formed thereon, and at a position below an upper large-diameter portion24a(an outer shape corresponding to the fit-insertion portion24in the first embodiment), a lower small-diameter portion24b, which is longer than the upper large-diameter portion24ain the vertical direction, is provided, and at a lower end of the lower small-diameter portion24b, a flanged abutment portion24cadapted to abut the stepped portion (terrace portion) between the recess hole20C and the reception hole18of the body member20A is provided such that it protrudes outward.

The lower small-diameter portion24bof the fit-insertion portion24has formed around its inner periphery the inner peripheral groove24d, which is long in the vertical direction, so as to receive the outer peripheral portion, which protrudes from the annular groove15i, of the sealing member14disposed in the annular groove15i.

Meanwhile, the recess hole20C of the body member20A of the valve body20also has a step formed thereon, and has an upper large-diameter hole20Ca (an outer shape corresponding to the recess hole20C in the first embodiment) into which the upper large-diameter portion24ais fitted and inserted, and a lower small-diameter hole20Cb into which the lower small-diameter portion24bis fitted and inserted, and further has a stepped reception hole18for storing the main valve element portion15aof the main valve element15in a manner continuous with the center of the bottom of the lower small-diameter hole20Cb. A valve closing spring50constructed from a conical compression coil spring is provided in a compressed state between the stepped portion provided on the inner periphery of the reception hole18and the stepped portion (terrace portion)15gprovided on the outer periphery of the bottom of the main valve element portion15aof the main valve element15.

The inside of the reception hole18(a portion below the valve orifice22of the support member20B) is the valve chamber21. Herein, the lower small-diameter hole20Cb in the recess hole20C has a plurality of Pd introduction ports25communicating with the discharge chamber106of the compressor100. A ring-like filter member25A is arranged around the outer periphery of the Pd introduction ports25thereof, and the lower small-diameter portion24bof the fit-insertion portion24(instead of the intermediate small-diameter portion15dof the main valve element15) has a plurality of horizontal holes25acommunicating with the Pd introduction ports25. The Pc inlet/outlet chamber (inlet/outlet port)26, which communicates with the crank chamber104of the compressor100, communicates with the Pd introduction ports25via the valve chamber21→a gap between the valve orifice22and the main valve element portion15a→a gap between the bottom of the guide hole19(upper guide hole19A) and the intermediate small-diameter portion15d→the horizontal holes25in the lower small-diameter portion24b→a gap between the lower small-diameter portion24band the lower small-diameter hole20Cb (which will be discussed in detail below).

In addition, in this embodiment, the outer periphery of the upper large-diameter portion24aabuts the inner periphery of the upper large-diameter hole20Ca (that is, the upper large-diameter portion24ais fitted into (fits snugly inside) the upper large-diameter hole20Ca), and the support member20B is fixedly inserted into the recess hole20C of the body member20A in a posture in which a small gap is provided between the outer periphery of the lower small-diameter portion24band the inner periphery of the lower small-diameter hole20Cb.

In the control valve2in this embodiment also, when the valve orifice20is closed by the main valve element portion15aof the main valve element15(the states shown inFIGS. 8 and 9), the inside of the lower small-diameter hole20Cb communicating with the discharge chamber106of the compressor100via the Pd introduction ports25has a pressure higher than that in the inlet/outlet chamber28communicating with the suction chamber107of the compressor100via the Ps inlet/outlet ports27. Therefore, the sealing member14, which is vertically movably disposed in the annular groove15iof the main valve element15such that it is arranged in the lower small-diameter hole20Cb, is pressed so as to be tightly in contact with an end portion62on the lower small-diameter hole20Cb side (higher pressure side) in a gap63between sliding surfaces64a,64b, which is formed between the top fit-insertion portion15e(or the outer peripheral surface thereof) of the main valve element15and the guide hole19(upper guide hole19A) (or the inner peripheral surface thereof), due to the difference in pressure between the lower small-diameter hole20Cb and the inlet/outlet chamber28(herein, the outer peripheral portion of the sealing member14is made to abut the upper planar surface61(planar portion) of the inner peripheral groove24dthat forms the end portion62on the lower small-diameter hole20Cb side (higher pressure side) in the gap63between the sliding surfaces64a,64b). Thus, the sealing member14seals the gap63between the sliding surfaces64a,64bat a position between the lower small-diameter hole20Cb and the inlet/outlet chamber28.

Therefore, the control valve2in the second embodiment with the aforementioned configuration can also obtain operational effects similar to those of the control valve1in the first embodiment.

It should be noted that in the second embodiment, the dimensions and the shape of the annular groove15iof the main valve element15and the like are designed such that when the valve orifice20is opened (the state shown inFIGS. 7A-7B), the sealing member14is separated from the end portion62on the lower small-diameter hole20Cb side (higher pressure side) in the gap63between the sliding surfaces.

The first and second embodiments have adopted the control valves1and2of a type in which the valve element10includes the main valve element15and the sub valve element17, and the pressure Pc in the crank chamber104of the compressor100is released to the suction chamber107via the Ps inlet/outlet ports27using the in-valve release passage16(release through-hole16A) formed in the main valve element15. However, it is needless to mention that the present invention can also be applied to a control valve of a type in which the main valve element15and the sub valve element17of the valve element10are integrally formed and the release through-hole in the main valve element15(and the in-valve release passage accordingly) is omitted (see Patent Document 1, for example).

DESCRIPTION OF SYMBOLS