Patent Description:
A variable displacement compressor used for an air conditioning system of an automobile, etc. includes a rotating shaft to be driven and rotated by an engine, a swash plate coupled to the rotating shaft in such a manner that a tilt angle is variable, compressing pistons coupled to the swash plate, etc., and by changing the tilt angle of the swash plate, changes a stroke amount of the pistons to control a discharge amount of fluid. This tilt angle of the swash plate can be continuously changed by appropriately controlling pressure in a control chamber while utilizing a suction pressure Ps of a suction chamber that suctions the fluid, a discharge pressure Pd of a discharge chamber that discharges the fluid pressurized by the pistons, and a control pressure Pc of the control chamber that houses the swash plate, by means of a capacity control valve to be driven to open and close by electromagnetic force.

At the time of continuously driving the variable displacement compressor, the capacity control valve performs normal control in which energization is controlled by a control computer, a valve body is moved in an axial direction by electromagnetic force generated in a solenoid, and a main valve provided between a discharge port through which a discharge fluid of the discharge pressure Pd passes and a control port through which a control fluid of the control pressure Pc passes is opened and closed to adjust the control pressure Pc of the control chamber of the variable displacement compressor.

During normal control of the capacity control valve, the pressure of the control chamber in the variable displacement compressor is appropriately controlled, and the tilt angle of the swash plate with respect to the rotating shaft is continuously changed to change the stroke amount of the pistons and to control the amount of discharge of the fluid to the discharge chamber, so that the air conditioning system is adjusted to have a target cooling capacity. In addition, when the variable displacement compressor is driven at the maximum capacity, the main valve of the capacity control valve is closed to lower the pressure of the control chamber, so that the tilt angle of the swash plate is maximized.

In addition, a configuration has been known in which an auxiliary communication passage is formed that provides communication between a control port and a suction port of a capacity control valve, and a refrigerant of a control chamber of a variable displacement compressor is discharged to a suction chamber of the variable displacement compressor through the control port, the auxiliary communication passage, and the suction port at a start-up, to rapidly lower the pressure of the control chamber at the start-up, so that the responsiveness of the variable displacement compressor is improved (refer to Patent Citation <NUM>). Another capacity control valve is known from <CIT>.

Patent Citation <NUM>: <CIT> (PAGE <NUM> and <FIG>).

However, according to the configuration disclosed in Patent Citation <NUM>, a fluid discharge function at a start-up is good, but at the time of continuously driving the variable displacement compressor, the auxiliary communication passage allows communication, and the refrigerant flows from the control port into the suction port, so that the refrigerant circulation amount increases and the operating efficiency of the variable displacement compressor decreases, which is a problem.

The present invention is conceived in view of such a problem, and an object of the present invention is to provide a capacity control valve having a fluid discharge function at a start-up and having good operating efficiency.

In order to solve the foregoing problem, according to the present invention, there is provided a capacity control valve including: a valve housing provided with a discharge port through which a discharge fluid of a discharge pressure passes, a suction port through which a suction fluid of a suction pressure passes, and a control port through which a control fluid of a control pressure passes; a main valve including a valve body driven by a solenoid, and a main valve seat which is provided between the discharge port and the control port and with which the valve body is allowed to come into contact; a pressure sensitive body disposed in a pressure sensitive chamber; and a pressure sensitive valve member extending from the valve body to the pressure sensitive chamber and forming a pressure sensitive valve, together with the pressure sensitive body. An intermediate communication passage is formed in the valve body and in the pressure sensitive valve member, and the control port and the suction port are allowed to communicate with each other through the intermediate communication passage by opening and closing of the pressure sensitive valve. The pressure sensitive valve member is provided with a through-hole communicating with the intermediate communication passage and has a slide valve body attached thereto such that the slide valve body slides relative to the pressure sensitive valve member in the pressure sensitive chamber to open and close the through-hole. The slide valve body partitions the pressure sensitive chamber into a Pd side space on a side of the discharge port and a Pc side space on a side of the control port, and a Pd-Pc flow passage providing communication between the Pd side space and the PC side space is formed in the slide valve body. According to the aforesaid feature of the present invention, the slide valve body partitions the pressure sensitive chamber into the Pd side space communicating with the discharge port and the Pc side space communicating with the control port, and when the main valve is controlled in an energized state, a flow of the fluid flowing from the discharge port to the control port due to opening of the main valve can be supplied through the Pd-Pc flow passage such as an opening or a cutout formed in the slide valve body, and the slide valve body is slid to the control port side using the force of the fluid, to close the through-hole of the pressure sensitive valve member and to shut off communication between the control port and the suction port, so that the fluid can be prevented from flowing into the suction port from the control port. On the other hand, when the main valve is closed at a start-up, the fluid of high pressure flows from the outside of the capacity control valve into the Pc side space of the pressure sensitive chamber through the control port to generate a differential pressure between the Pd side space and the Pc side space, and the slide valve body is slid to the discharge port side using the differential pressure, to open the through-hole of the pressure sensitive valve member and to provide communication between the control port and the suction port, so that the control pressure can be quickly lowered. In such a manner, the discharge of a liquid refrigerant and the operating efficiency at a start-up of the variable displacement compressor can be improved.

It may be preferable that the slide valve body slides along an outer peripheral surface of the pressure sensitive valve member. According to this preferable configuration, since the slide valve body slides along the pressure sensitive valve member, the slide valve body can reliably close the through-hole.

It may be preferable that the Pd-Pc flow passage is formed by a communication hole penetrating through the slide valve body in an axial direction. According to this preferable configuration, the amount of release of the fluid through the Pd-Pc flow passage of the slide valve body can be easily adjusted according to the number or the size of the communication holes, and the operation accuracy of the slide valve body can be improved.

It may be preferable that a plurality of the Pd-Pc flow passages are evenly disposed in a circumferential direction. According to this preferable configuration, since the slide valve body can receive forces due to the fluids in a well-balanced manner, the slide valve body can be stably operated.

It may be preferable that a projection is be provided between the slide valve body and a flange portion formed on a tip side of the pressure sensitive valve member. According to this preferable configuration, in a state where the through-hole of the pressure sensitive valve member is closed by the slide valve body, the projection prevents surface-to-surface contact between a side surface of the slide valve body and a side surface of the flange portion of the pressure sensitive valve member, so that the slide valve body can be easily separated from the pressure sensitive valve member, and the responsiveness of the slide valve body can be improved.

It may be preferable that the projection is formed in the slide valve body so as to protrude toward the flange portion. According to this preferable configuration, in a state where the through-hole of the pressure sensitive valve member is closed by the slide valve body, a large pressure receiving area can be secured by the side surface facing the Pc side space, so that the slide valve body is easily operated in an opening direction by a differential pressure.

It may be preferable that the valve housing is provided with a stopper that restricts movement of the slide valve body in an opening direction. According to this preferable configuration, since the stopper can specify the amount of movement of the slide valve body, the controllability of the slide valve body is high.

Modes for carrying out a capacity control valve according to the present invention will be described below based on an embodiment.

A capacity control valve according to a first embodiment of the present invention will be described with reference to <FIG>. Hereinafter, a description will be given based on the assumption that the left and right sides when seen from the front side of <FIG> are left and right sides of the capacity control valve. In detail, a description will be given based on the assumption that the left side of the drawing sheet on which a pressure sensitive body <NUM> is disposed is the left side of the capacity control valve and the right side of the drawing sheet on which a solenoid <NUM> is disposed is the right side of the capacity control valve.

A capacity control valve V1 of the present invention is assembled into a variable displacement compressor M used for an air conditioning system of an automobile, etc., and by variably controlling the pressure of a working fluid (hereinafter, simply referred to as a "fluid") that is a refrigerant, controls the discharge amount of the variable displacement compressor M to adjust the air conditioning system to have a target cooling capacity.

First, the variable displacement compressor M will be described. As shown in <FIG>, the variable displacement compressor M includes a casing <NUM> including a discharge chamber <NUM>, a suction chamber <NUM>, a control chamber <NUM>, and a plurality of cylinders 4a. Incidentally, the variable displacement compressor M is provided with a communication passage (not shown) that provides direct communication between the control chamber <NUM> and the suction chamber <NUM>, and the communication passage is provided with a fixed orifice that balances the pressures of the suction chamber <NUM> and the control chamber <NUM>.

In addition, the variable displacement compressor M includes a rotating shaft <NUM> to be driven and rotated by an engine (not shown) installed outside the casing <NUM>; a swash plate <NUM> coupled to the rotating shaft <NUM> so as to be tiltable by a hinge mechanism <NUM> in the control chamber <NUM>; and a plurality of pistons <NUM> that are coupled to the swash plate <NUM> and that are reciprocatably fitted in the respective cylinders 4a, and appropriately controls pressure in the control chamber <NUM> by means of the capacity control valve V1 to be driven to open and close by electromagnetic force, while utilizing a suction pressure Ps of the suction chamber <NUM> that suctions the fluid, a discharge pressure Pd of the discharge chamber <NUM> that discharges the fluid pressurized by the pistons <NUM>, and a control pressure Pc of the control chamber <NUM> that houses the swash plate <NUM>, to continuously change the tilt angle of the swash plate <NUM>, and thus to change the stroke amount of the pistons <NUM> and to control the discharge amount of the fluid. Incidentally, for convenience of description, the capacity control valve V1 assembled into the variable displacement compressor M is not shown in <FIG>.

Specifically, the higher the control pressure Pc in the control chamber <NUM>, the smaller the tilt angle of the swash plate <NUM> with respect to the rotating shaft <NUM>, and thus the stroke amounts of the pistons <NUM> are reduced, and when the control pressure Pc is a certain pressure or higher, the swash plate <NUM> is substantially perpendicular to the rotating shaft <NUM>, namely, is slightly tilted with respect to perpendicularity. At this time, since the stroke amount of the pistons <NUM> is minimized and the pressurization of the fluid in the cylinders 4a by the pistons <NUM> is minimized, the amount of discharge of the fluid to the discharge chamber <NUM> is reduced, and the cooling capacity of the air conditioning system is minimized. On the other hand, the lower the control pressure Pc in the control chamber <NUM> is, the larger the tilt angle of the swash plate <NUM> with respect to the rotating shaft <NUM> is to increase the stroke amount of the pistons <NUM>, and when the control pressure Pc reaches a certain pressure or lower, the swash plate <NUM> has a maximum tilt angle with respect to the rotating shaft <NUM>. In this case, since the stroke amounts of the pistons <NUM> are maximized and the pressurization of the fluid in the cylinders 4a by the pistons <NUM> is maximized, the discharge amount of the fluid to the discharge chamber <NUM> is increased, and the cooling capacity of the air conditioning system is maximized.

As shown in <FIG>, the capacity control valve V1 assembled into the variable displacement compressor M controls an electric current that energizes a coil <NUM> forming the solenoid <NUM>, to perform opening and closing control of a main valve <NUM> and an auxiliary valve <NUM> in the capacity control valve V1, and performs opening and closing control of a pressure sensitive valve <NUM> using the suction pressure Ps and controls the fluid flowing into the control chamber <NUM> or flowing out from the control chamber <NUM>, to variably control the control pressure Pc in the control chamber <NUM>.

In the present embodiment, the main valve <NUM> includes a main and auxiliary valve body <NUM> serving as a valve body and a main valve seat 10a that is formed at an annular protrusion 10c having an isosceles trapezoidal shape in a cross-sectional view and protruding from an inner peripheral surface of a valve housing <NUM> to a radially inner side, and an axially left end surface 51a of the main and auxiliary valve body <NUM> comes into contact with and separates from the main valve seat 10a to open and close the main valve <NUM>. The auxiliary valve <NUM> includes the main and auxiliary valve body <NUM> and an auxiliary valve seat 82a formed in an opening end surface of a fixed iron core <NUM>, namely, in an axially left end surface of the fixed iron core <NUM>, and a step portion 51b on an axially right side of the main and auxiliary valve body <NUM> comes into contact with and separates from the auxiliary valve seat 82a to open and close the auxiliary valve <NUM>. The pressure sensitive valve <NUM> includes an adapter <NUM> of the pressure sensitive body <NUM> and a pressure sensitive valve seat 52a formed at an axially left end surface of a pressure sensitive valve member <NUM>, and an axially right end surface 70a of the adapter <NUM> comes into contact with and separates from the pressure sensitive valve seat 52a to open and close the pressure sensitive valve <NUM>.

Next, a structure of the capacity control valve V1 will be described. As shown in <FIG>, the capacity control valve V1 mainly includes the valve housing <NUM> made of a metallic material or a resin material; the main and auxiliary valve body <NUM> and the pressure sensitive valve member <NUM> disposed inside the valve housing <NUM> so as to be reciprocatable in an axial direction; the pressure sensitive body <NUM> that applies a biasing force to the main and auxiliary valve body <NUM> and to the pressure sensitive valve member <NUM> to the right in the axial direction according to the suction pressure Ps; the solenoid <NUM> connected to the valve housing <NUM> to exert a driving force on the main and auxiliary valve body <NUM> and on the pressure sensitive valve member <NUM>; and a slide valve body <NUM> provided to be reciprocatable relative to the pressure sensitive valve member <NUM> in the axial direction by opening and closing of the main valve <NUM>. Since the slide valve body <NUM> opens and closes a flow passage between an auxiliary valve chamber <NUM> and a pressure sensitive chamber <NUM> that have the suction pressure Ps and the control pressure Pc, respectively, when the slide valve body <NUM> reciprocates, it can be said that the slide valve body <NUM> forms a CS valve, together with the pressure sensitive valve member <NUM>, the CS valve rapidly releasing the control pressure Pc of the control chamber <NUM> to the suction chamber <NUM> through a through-hole 52d of the pressure sensitive valve member <NUM> and through an intermediate communication passage <NUM> to be described later.

As shown in <FIG>, the solenoid <NUM> mainly includes a casing <NUM> including an opening portion 81a that is open to the left in the axial direction; the fixed iron core <NUM> having a substantially cylindrical shape and being inserted into the opening portion 81a of the casing <NUM> from the left in the axial direction to be fixed to a radially inner side of the casing <NUM>; a drive rod <NUM> which is reciprocatable in the axial direction on the radially inner side of the fixed iron core <NUM> and of which an axially left end portion is connected and fixed to the main and auxiliary valve body <NUM>; a movable iron core <NUM> firmly fixed to an axially right end portion of the drive rod <NUM>; a coil spring <NUM> provided between the fixed iron core <NUM> and the movable iron core <NUM> to bias the movable iron core <NUM> to the right in the axial direction; and a coil <NUM> for excitation wound on an outer side of the fixed iron core <NUM> with a bobbin interposed therebetween.

A recessed portion 81b that is recessed to the right in the axial direction is formed on a radially inner side of an axially left side of the casing <NUM>, and an axially right end portion of the valve housing <NUM> is inserted and fixed to the recessed portion 81b in a substantially sealed state.

The fixed iron core <NUM> is made of a rigid body that is a magnetic material such as iron or silicon steel, and includes a cylindrical portion 82b which extends in the axial direction and in which an insertion hole 82c into which the drive rod <NUM> is inserted is formed, and a flange portion 82d having an annular shape and extending from an outer peripheral surface of an axially left end portion of the cylindrical portion 82b in a radially outward direction, and a recessed portion 82e that is recessed to the right in the axial direction is formed on a radially inner side of an axially left side of the cylindrical portion 82b.

As shown in <FIG>, a Pd port <NUM> that is a discharge port communicating with the discharge chamber <NUM> of the variable displacement compressor M, a Ps port <NUM> that is a suction port communicating with the suction chamber <NUM> of the variable displacement compressor M, and a Pc port <NUM> that is a control port communicating with the control chamber <NUM> of the variable displacement compressor M are formed in the valve housing <NUM>.

A partition adjustment member <NUM> is press-fitted into an axially left end portion of the valve housing <NUM> in a substantially sealed state, so that the valve housing <NUM> has a substantially bottomed cylindrical shape. Incidentally, the partition adjustment member <NUM> can adjust the installation position of the valve housing <NUM> in the axial direction to adjust a biasing force of the pressure sensitive body <NUM>.

Inside the valve housing <NUM>, a main valve chamber <NUM> which communicates with the Pd port <NUM> and in which an axially left end surface 51a side of the main and auxiliary valve body <NUM> is disposed, the auxiliary valve chamber <NUM> which communicates with the Ps port <NUM> and in which a back pressure side of the main and auxiliary valve body <NUM>, namely, the step portion 51b on the axially right side of the main and auxiliary valve body <NUM> is disposed, and the pressure sensitive chamber <NUM> which communicates with the Pc port <NUM> and in which the pressure sensitive valve member <NUM>, the slide valve body <NUM>, and the pressure sensitive body <NUM> are disposed are formed.

In addition, the main and auxiliary valve body <NUM> and the pressure sensitive valve member <NUM> inserted and fixed to the main and auxiliary valve body <NUM> are disposed inside the valve housing <NUM> so as to be reciprocatable in the axial direction, and a guide hole 10b which has a small diameter and with which an outer peripheral surface of the main and auxiliary valve body <NUM> is in slidable contact in a substantially sealed state is formed at an axially right end portion of the inner peripheral surface of the valve housing <NUM>. Further, inside the valve housing <NUM>, the main valve chamber <NUM> and the auxiliary valve chamber <NUM> are partitioned off by the outer peripheral surface of the main and auxiliary valve body <NUM> and an inner peripheral surface of the guide hole 10b. Incidentally, the inner peripheral surface of the guide hole 10b and the outer peripheral surface of the main and auxiliary valve body <NUM> are slightly separated from each other in a radial direction to form a very small gap therebetween, and the main and auxiliary valve body <NUM> is smoothly movable relative to the valve housing <NUM> in the axial direction.

As shown in <FIG>, the pressure sensitive body <NUM> mainly includes a bellows core <NUM> in which a coil spring <NUM> is built-in, and the adapter <NUM> provided at an axially right end portion of the bellows core <NUM>, and an axially left end surface of the bellows core <NUM> is fixed to the partition adjustment member <NUM>.

In addition, the pressure sensitive body <NUM> is disposed in the pressure sensitive chamber <NUM>, and the axially right end surface 70a of the adapter <NUM> is seated on the pressure sensitive valve seat 52a of the pressure sensitive valve member <NUM> by a biasing force of the coil spring <NUM> and the bellows core <NUM> to move the adapter <NUM> to the right in the axial direction. In addition, a force to the left in the axial direction is applied to the adapter <NUM> according to the suction pressure Ps in the intermediate communication passage <NUM>.

As shown in <FIG>, the main and auxiliary valve body <NUM> is formed in a substantially cylindrical shape. The pressure sensitive valve member <NUM> that is separately formed in a flanged cylindrical shape and in a substantially turret shape in a side view is inserted and fixed to an axially left end portion of the main and auxiliary valve body <NUM> in a substantially sealed state, and the drive rod <NUM> is inserted and fixed to an axially right end portion of the main and auxiliary valve body <NUM> in a substantially sealed state. The main and auxiliary valve body <NUM>, the pressure sensitive valve member <NUM>, and the drive rod <NUM> are movable together in the axial direction.

In addition, since the labyrinth effect of annular grooves formed in the outer peripheral surface of the main and auxiliary valve body <NUM> can suppress the leakage of the fluid from the main valve chamber <NUM> to the auxiliary valve chamber <NUM>, the discharge pressure Pd of the discharge fluid supplied from the discharge chamber <NUM> to the main valve chamber <NUM> via the Pd port <NUM> is maintained.

Incidentally, hollow holes inside the main and auxiliary valve body <NUM> and inside the pressure sensitive valve member <NUM> are connected to each other to form the intermediate communication passage <NUM> penetrating therethrough in the axial direction. Incidentally, the intermediate communication passage <NUM> communicates with the auxiliary valve chamber <NUM> via a plurality of through-holes 51c penetrating through the axially right end portion of the main and auxiliary valve body <NUM> in the radial direction.

As shown in <FIG>, the pressure sensitive valve member <NUM> is made of a metallic material or a resin material, and is formed in a flanged cylindrical shape and in a substantially turret shape in a side view that includes a base portion 52b having a cylindrical shape of which an axially right end portion is inserted and fixed to the main and auxiliary valve body <NUM> in a substantially sealed state and to which the slide valve body <NUM> is externally fitted, and a flange portion 52c which extends from an outer peripheral surface of an axially left end portion of the base portion 52b in the radially outward direction and in which the pressure sensitive valve seat 52a that comes into contact with and separates from the axially right end surface 70a of the adapter <NUM> is formed. Incidentally, a plurality of the through-holes 52d penetrating through the base portion 52b in the radial direction and communicating with the intermediate communication passage <NUM> are formed at the axially left end portion of the base portion 52b.

As shown in <FIG>, the slide valve body <NUM> is formed as a member separated from the pressure sensitive valve member <NUM>, is externally fitted to the base portion 52b of the pressure sensitive valve member <NUM>, and is formed in an annular shape having a predetermined thickness dimension L1 in the axial direction (refer to <FIG>). Incidentally, the thickness dimension L1 of the slide valve body <NUM> is larger than a diameter R1 (refer to <FIG>) of the through-hole 52d of the pressure sensitive valve member <NUM> (i.e., L1 > R1).

In addition, as shown in <FIG>, a through-hole 90a into which the base portion 52b of the pressure sensitive valve member <NUM> is inserted is formed at the center of the slide valve body <NUM>, and a plurality of communication holes 90b serving as Pd-Pc flow passages and penetrating through the slide valve body <NUM> in the axial direction are evenly disposed in a radially outer portion of the slide valve body <NUM> in a circumferential direction. Incidentally, in the present embodiment, eight communication holes 90b having the same diameter are evenly disposed in the slide valve body <NUM> in the circumferential direction, but the invention is not limited to the configuration, and the diameter, the number, and the disposition of the communication holes 90b may be freely configured.

In addition, as shown in <FIG>, an inner diameter of the slide valve body <NUM> is larger than an outer diameter of the base portion 52b of the pressure sensitive valve member <NUM>, and an inner peripheral surface of the through-hole 90a of the slide valve body <NUM> (hereinafter, simply referred to as the "inner peripheral surface of the slide valve body <NUM>") is slidable on an outer peripheral surface <NUM> of the base portion 52b of the pressure sensitive valve member <NUM>. Accordingly, the reciprocation of the slide valve body <NUM> in the axial direction is guided by the outer peripheral surface <NUM> of the base portion 52b of the pressure sensitive valve member <NUM>, and the tilting of the slide valve body <NUM> is suppressed. In addition, through-holes 52d of the pressure sensitive valve member <NUM> can be reliably closed by the slide valve body <NUM>.

In addition, an outer diameter of the slide valve body <NUM> is larger than an outer diameter of the flange portion 52c of the pressure sensitive valve member <NUM>, and an outer peripheral surface 90e of the slide valve body <NUM> is disposed close to an inner peripheral surface 10d of the valve housing <NUM>. In detail, the outer peripheral surface 90e of the slide valve body <NUM> and the inner peripheral surface 10d of the valve housing <NUM> are slightly separated from each other in the radial direction to form a very small gap therebetween, and the slide valve body <NUM> is smoothly movable relative to the valve housing <NUM> in the axial direction. The very small gap formed between the outer peripheral surface 90e of the slide valve body <NUM> and the inner peripheral surface 10d of the valve housing <NUM> is formed to be larger than a very small gap formed between the inner peripheral surface of the slide valve body <NUM> and the outer peripheral surface <NUM> of the base portion 52b of the pressure sensitive valve member <NUM>. Incidentally, the communication holes 90b are formed at a position on a radially outer side of the flange portion 52c of the pressure sensitive valve member <NUM>.

In addition, the slide valve body <NUM> partitions the pressure sensitive chamber <NUM> into a Pd side space S1 communicating with the Pd port <NUM> on an axially right side of the slide valve body <NUM> and a Pc side space S2 communicating with the Pc port <NUM> on an axially left side of the slide valve body <NUM>, and the Pd side space S1 and the Pc side space S2 communicate with each other through the communication holes 90b. Incidentally, the fluid moves between the Pd side space S1 and the Pc side space S2 mainly through the communication holes 90b, and the amount of release of the fluid through the very small gap formed between the outer peripheral surface 90e of the slide valve body <NUM> and the inner peripheral surface 10d of the valve housing <NUM> is a very small amount that does not affect a reciprocating operation of the slide valve body <NUM> to be described later.

In addition, when the slide valve body <NUM> closes the through-holes 52d of the pressure sensitive valve member <NUM> moving to the left in the axial direction (refer to <FIG>), a side surface 90c on the axially left side of the slide valve body <NUM> comes into contact with a side surface 52e on an axially right side of the flange portion 52c of the pressure sensitive valve member <NUM>. Accordingly, an axial position of the slide valve body <NUM> when the through-holes 52d of the pressure sensitive valve member <NUM> are closed by the slide valve body <NUM> is determined.

In addition, when the slide valve body <NUM> closes the through-holes 52d of the pressure sensitive valve member <NUM> moving to the left in the axial direction, a radially outer side of the side surface 90c on the axially left side of the slide valve body <NUM> with respect to the flange portion 52c of the pressure sensitive valve member <NUM> is exposed to the Pc side space S2. On the other hand, the entirety of a side surface 90d on the axially right side of the slide valve body <NUM> from the radially inner side to a radially outer side is exposed to the Pd side space S1 regardless of movement of the slide valve body <NUM>.

Incidentally, the through-holes 52d of the pressure sensitive valve member <NUM> are formed on an axially right side of the side surface 52e on the axially right side of the flange portion 52c, and until the slide valve body <NUM> moves to the axial position of axially left opening ends of the through-holes 52d from a state where the slide valve body <NUM> is in contact with the side surface 52e of the flange portion 52c of the pressure sensitive valve member <NUM>, a state where the slide valve body <NUM> overlaps the through-holes 52d in the radial direction to close the through-holes 52d is maintained.

Next, operation of the capacity control valve V1, mainly operation of an opening and closing mechanism of the through-holes 52d of the pressure sensitive valve member <NUM> performed by the slide valve body <NUM> will be described in order of at a start-up and during normal control.

First, operation during normal control will be described. During normal control, the opening degree or the opening time of the main valve <NUM> is adjusted by duty control of the capacity control valve V1, to control the flow rate of the fluid from the Pd port <NUM> to the Pc port <NUM>. At this time, the fluid that has flowed in from the Pd port <NUM> by opening of the main valve <NUM> flows to the Pc port <NUM> through the communication holes 90b of the slide valve body <NUM> (shown by solid arrows in <FIG>). The side surface 90d on the axially right side of the slide valve body <NUM> receives the force of the fluid, so that a force to move the slide valve body <NUM> to the left in the axial direction acts on the slide valve body <NUM> (shown by a white arrow in <FIG>), and the slide valve body <NUM> moves to the left in the axial direction to close the through-holes 52d of the pressure sensitive valve member <NUM> (refer to <FIG>).

At this time, in addition to a force Ff due to a flow of the fluid passing through the communication holes 90b generated by opening of the main valve <NUM>, a force FP1 due to the pressure of the fluid in the Pd side space S1 of the pressure sensitive chamber <NUM> act on a pressure-receiving surface of the slide valve body <NUM> toward the left in the axial direction, the pressure-receiving surface being formed by the side surface 90d on the axially right side of the slide valve body <NUM>, and a force FP2 due to the pressure of the fluid in the Pc side space S2 of the pressure sensitive chamber <NUM> acts on a pressure-receiving surface of the slide valve body <NUM> toward the right in the axial direction, the pressure-receiving surface being formed by the radially outer side of the side surface 90c on the axially left side of the slide valve body <NUM>. Namely, a force FSV = Ff + FP1 - FP2 acts on the slide valve body <NUM> with the left defined as positive.

In detail, in the present embodiment, the fluid flowing into the Pd side space S1 is the discharge fluid supplied from the Pd port <NUM> by opening of the main valve <NUM>, and has a higher pressure than the control fluid supplied to the Pc side space S2 from the Pc port <NUM>, and the pressure-receiving surface of the side surface 90d on the axially right side of the slide valve body <NUM> on which the pressure of the fluid in the Pd side space S1 acts is formed to be larger than the side surface 90c on the axially left side of the slide valve body <NUM> on which the pressure of the fluid in the Pc side space S2 acts.

Namely, the force FP1 due to the pressure of the fluid acting on the slide valve body <NUM> toward the left in the axial direction is larger than the force FP2 due to the pressure of the fluid acting on the slide valve body <NUM> toward the right in the axial direction (i.e., FP1 > FP2), and a closed state of the through-holes 52d of the pressure sensitive valve member <NUM> can be reliably maintained by a resultant force Ff + FP1 of the force FP1 and the force Ff due to a flow of the fluid acting toward the left in the axial direction.

As described above, during normal control, when the slide valve body <NUM> closes the through-holes 52d of the pressure sensitive valve member <NUM>, since a flow passage leading from the control chamber <NUM> to the suction chamber <NUM> through the Pc port <NUM>, then through the pressure sensitive chamber <NUM>, then through the through-holes 52d, then through the intermediate communication passage <NUM>, then through the auxiliary valve chamber <NUM>, and then through the Ps port <NUM> is not formed, the rate of outflow of the refrigerant from the control chamber <NUM> to the suction chamber <NUM> is reduced, so that the operating efficiency of the variable displacement compressor M can be improved.

Next, operation at a start-up will be described. After the variable displacement compressor M is left without being used for a long time, the discharge pressure Pd, the control pressure Pc, and the suction pressure Ps are substantially in equilibrium. Incidentally, although not shown for convenience of description, the fluid of high pressure in the control chamber <NUM> may be liquefied when the variable displacement compressor M is left in a stopped state for a long time, and at this time, due to the high suction pressure Ps in the intermediate communication passage <NUM>, the pressure sensitive body <NUM> is contracted and actuated to separate the axially right end surface 70a of the adapter <NUM> from the pressure sensitive valve seat 52a of the pressure sensitive valve member <NUM>, so that the pressure sensitive valve <NUM> is opened. As described above, for example, when the suction pressure Ps is high at a start-up, the liquid refrigerant in the control chamber <NUM> can be discharged to the suction chamber <NUM> via the intermediate communication passage <NUM> in a short time by opening of the pressure sensitive valve <NUM>.

In a non-energized state of the capacity control valve V1, the movable iron core <NUM> is pressed to the right in the axial direction by a biasing force of the coil spring <NUM> forming the solenoid <NUM> or by the biasing force of the coil spring <NUM> and of the bellows core <NUM> that form the pressure sensitive body <NUM>, so that the drive rod <NUM>, the main and auxiliary valve body <NUM>, and the pressure sensitive valve member <NUM> move to the right in the axial direction, the step portion 51b on the axially right side of the main and auxiliary valve body <NUM> is seated on the auxiliary valve seat 82a of the fixed iron core <NUM> to close the auxiliary valve <NUM>, and the axially left end surface 51a of the main and auxiliary valve body <NUM> separates from the main valve seat 10a formed in the inner peripheral surface of the valve housing <NUM>, to open the main valve <NUM> (refer to <FIG> and <FIG>). At this time, the slide valve body <NUM> is located on the left in the axial direction due to the force of the fluid supplied by opening of the main valve <NUM> described above, to close the through-holes 52d of the pressure sensitive valve member <NUM>.

Due to electromagnetic force generated by the application of an electric current to the solenoid <NUM> when the variable displacement compressor M is started up and the capacity control valve V1 is energized, the movable iron core <NUM> is pulled to the left in the axial direction toward the fixed iron core <NUM>, the drive rod <NUM> fixed to the movable iron core <NUM>, the main and auxiliary valve body <NUM>, and the pressure sensitive valve member <NUM> move together to the left in the axial direction, and the pressure sensitive body <NUM> is pressed and contracted to the left in the axial direction, so that the step portion 51b on the axially right side of the main and auxiliary valve body <NUM> separates from the auxiliary valve seat 82a to open the auxiliary valve <NUM>, and the axially left end surface 51a of the main and auxiliary valve body <NUM> is seated on the main valve seat 10a to close the main valve <NUM> (refer to <FIG>).

Incidentally, as shown in <FIG>, immediately after the main valve <NUM> is closed, the force Ff due to a flow of the fluid acting toward the left in the axial direction does not act on the slide valve body <NUM>, but the slide valve body <NUM> moves, together with the pressure sensitive valve member <NUM>, to the left in the axial direction from a position before the start-up (refer to <FIG>) to a position where the axially left end surface 51a of the main and auxiliary valve body <NUM> is seated on the main valve seat 10a, and a closed state of the through-holes 52d of the pressure sensitive valve member <NUM> is maintained. Incidentally, the movement of the slide valve body <NUM> is slightly delayed with respect to the movement of the pressure sensitive valve member <NUM>, but the slide valve body <NUM> moves due to inertia, and is pressed against the side surface 52e of the flange portion 52c of the pressure sensitive valve member <NUM>.

In addition, immediately after the variable displacement compressor M is started up, the control pressure Pc of the control chamber <NUM> may increase, and in this case, the control fluid of the high control pressure Pc flows into the Pc side space S2 of the pressure sensitive chamber <NUM> from the Pc port <NUM>.

Accordingly, the force FP2 due to the pressure of the fluid acting on the slide valve body <NUM> toward the right in the axial direction is temporarily higher than the force FP1' due to the pressure of the fluid acting on the slide valve body <NUM> toward the left in the axial direction (i.e., FP1' < FP2), and due to a difference in the pressures acting on the side surfaces 90c and 90d on both axial sides of the slide valve body <NUM>, a force to move the slide valve body <NUM> to the right in the axial direction acts on the slide valve body <NUM> (shown by a white arrow in <FIG>), and the through-holes 52d of the pressure sensitive valve member <NUM> are opened (refer to <FIG>). As described above, even when the through-holes 52d of the pressure sensitive valve member <NUM> are closed by the slide valve body <NUM> immediately after the main valve <NUM> is closed, the differential pressure generated between the Pd side space S1 and Pc side space S2 due to the start-up of the variable displacement compressor M moves the slide valve body <NUM> to the right in the axial direction, so that the through-holes 52d of the pressure sensitive valve member <NUM> can be reliably opened.

In addition, the fluid in the Pd side space S1 is compressed as the slide valve body <NUM> moves to the right in the axial direction. Accordingly, the pressure of the Pd side space S1 increases, and the slide valve body <NUM> is stopped at a position where the pressure of the Pd side space S1 and the pressure of the Pc side space S2 are balanced. Incidentally, while the main valve <NUM> is closed, a state where the pressure of the Pd side space S1 and the pressure of the Pc side space S2 are balanced and the slide valve body <NUM> is stopped is maintained, but when the main valve <NUM> is opened, and the discharge fluid flows into the Pd side space S1 from the Pd port <NUM>, the balance between the pressure of the Pd side space S1 and the pressure of the Pc side space S2 is collapsed, and the slide valve body <NUM> moves to the left in the axial direction to close the through-holes 52d of the pressure sensitive valve member <NUM>.

As described above, when the slide valve body <NUM> opens the through-holes 52d of the pressure sensitive valve member <NUM> at a start-up, the pressure sensitive chamber <NUM> communicates with the intermediate communication passage <NUM> via the through-holes 52d and the fluid flows (shown by solid arrows in <FIG>). Namely, since the slide valve body <NUM> opens the through-holes 52d of the pressure sensitive valve member <NUM> to form a flow passage for the discharge of the fluid in order of the control chamber <NUM>, the Pc port <NUM>, the pressure sensitive chamber <NUM>, the through-holes 52d, the intermediate communication passage <NUM>, the auxiliary valve chamber <NUM>, the Ps port <NUM>, and the suction chamber <NUM>, the liquefied fluid of the control chamber <NUM> can be discharged in a short time to improve responsiveness at a start-up. In addition, for example, as described above, even when the pressure sensitive valve <NUM> is not opened by the suction pressure Ps at a start-up, the slide valve body <NUM> can open the through-holes 52d of the pressure sensitive valve member <NUM> to form the flow passage for the discharge of the fluid from the control chamber <NUM> to the suction chamber <NUM> via the intermediate communication passage <NUM>.

As described above, the slide valve body <NUM> partitions the pressure sensitive chamber <NUM> into the Pd side space S1 communicating with the Pd port <NUM> and the Pc side space S2 communicating with the Pc port <NUM>. During normal control of the capacity control valve V1, a flow of the fluid flowing from the Pd port <NUM> to the Pc port <NUM> due to opening of the main valve <NUM> can be supplied through the communication holes 90b formed in the slide valve body <NUM>, and the slide valve body <NUM> is moved to the left in the axial direction using the force of the fluid, to close the through-holes 52d of the pressure sensitive valve member <NUM>. At a start-up, when the main valve <NUM> is closed and the control pressure Pc of the control chamber <NUM> is high, the fluid of high pressure flows into the Pc side space S2 of the pressure sensitive chamber <NUM> from the control chamber <NUM> of the variable displacement compressor M through the Pc port <NUM> to generate a differential pressure between the Pd side space S1 and the Pc side space S2, and the slide valve body <NUM> is moved to the right in the axial direction using the differential pressure, to open the through-holes 52d of the pressure sensitive valve member <NUM>, so that the operating efficiency of the variable displacement compressor M can be improved.

In addition, the slide valve body <NUM> slides along the outer peripheral surface <NUM> of the base portion 52b of the pressure sensitive valve member <NUM>, so that the through-holes 52d of the pressure sensitive valve member <NUM> can be reliably closed by the slide valve body <NUM>.

In addition, it is preferable that the slide valve body <NUM> and the base portion 52b of the pressure sensitive valve member <NUM> are made of different materials, and the frictional resistance is reduced, so that the slide valve body <NUM> is smoothly slidable.

In addition, the communication holes 90b serving as the Pd-Pc flow passages which provide communication between the Pd port <NUM> and the Pc port <NUM> are formed in the slide valve body <NUM>, and the amount of release of the fluid can be easily adjusted according to the number or the size of the communication holes 90b, and the operation accuracy of the slide valve body <NUM> can be improved.

In addition, since the plurality of communication holes 90b are evenly disposed in the circumferential direction, and the side surfaces 90c and 90d on both axial sides of the slide valve body <NUM> can receive forces due to the fluids in a well-balanced manner, the slide valve body <NUM> can be stably operated.

Incidentally, as the Pd-Pc flow passages that provide communication between the Pd port <NUM> and the Pc port <NUM>, as shown in a modification example of <FIG>, a slide valve body <NUM> may be formed in a shape in which cutouts 190b are formed in an annular radially outer portion, so that Pd-Pc flow passages are formed by an outer peripheral surface of the slide valve body <NUM> and the inner peripheral surface 10d of the valve housing <NUM> (refer to two-dot chain lines in <FIG>). In addition, the shape, the number, and the disposition of the cutouts 190b may be freely configured. Furthermore, the configuration of the cutout in the modification example is also applicable to a slide valve body in each of the following second to fourth embodiments.

In addition, since the thickness dimension L1 of the slide valve body <NUM> is larger than the diameter R1 of the through-hole 52d of the pressure sensitive valve member <NUM> (i.e., L1 > R1) (refer to <FIG>), and until the slide valve body <NUM> moves to the right in the axial direction by the predetermined distance or more from a state where the side surface 90c on the axially left side is in contact with the side surface 52e of the flange portion 52c of the pressure sensitive valve member <NUM>, a state where the through-holes 52d of the pressure sensitive valve member <NUM> are closed can be maintained, even when the slide valve body <NUM> is slightly slide due to disturbance such as vibration, the through-holes 52d of the pressure sensitive valve member <NUM> are maintained in a closed state. For this reason, the capacity control valve V1 is resistant to disturbance, and has good control accuracy.

In addition, since the slide valve body <NUM> can be moved to the right in the axial direction by a differential pressure generated between the Pd side space S1 and the Pc side space S2 at a start-up, there is no need to separately provide biasing means such as a spring for opening the through-holes 52d of the pressure sensitive valve member <NUM>, so that the number of components of the capacity control valve V1 can be reduced.

In addition, since the plurality of through-holes 52d of the pressure sensitive valve member <NUM> are formed, a wide cross-sectional area of the flow passage for the discharge of the fluid from the Pc port <NUM> to the suction chamber <NUM> can be secured. In addition, since the plurality of through-holes 52d are evenly disposed in the circumferential direction, the stroke of the slide valve body <NUM> can be shortened.

A capacity control valve according to a second embodiment of the present invention will be described with reference to <FIG>. Incidentally, a description of duplicated configurations that are the same as the configurations of the first embodiment will be omitted.

As shown in <FIG>, in a capacity control valve V2 of the second embodiment, a slide valve body <NUM> is integrally provided with a projection 290e having an annular shape and protruding from a radially inner portion of a side surface 290c on an axially left side to the left in the axial direction. Incidentally, the projection 290e is not limited to being formed in an annular shape, and a plurality of the projections 290e may be evenly disposed in the circumferential direction. In addition, a member separated from the slide valve body <NUM> may be fixed to the side surface 290c to form the projection 290e.

Accordingly, in a state where the through-holes 52d of the pressure sensitive valve member <NUM> are closed by the slide valve body <NUM>, a tip surface of the projection 290e is in contact with the side surface 52e of the flange portion 52c of the pressure sensitive valve member <NUM> to prevent surface-to-surface contact between the side surface 290c on the axially left side of the slide valve body <NUM> and the side surface 52e of the flange portion 52c of the pressure sensitive valve member <NUM>, so that the slide valve body <NUM> can be easily separated from the pressure sensitive valve member <NUM>, and the responsiveness of the slide valve body <NUM> can be improved.

In addition, since the projection 290e is provided on a radially inner side of the slide valve body <NUM>, in a state where the through-holes 52d of the pressure sensitive valve member <NUM> are closed by the slide valve body <NUM>, a large pressure receiving area up to the radially inner side can be secured by the side surface 290c exposed to the Pc side space S2, so that the slide valve body <NUM> is easily operated in an opening direction using a differential pressure generated between the Pd side space S1 and the Pc side space S2.

A capacity control valve according to a third embodiment of the present invention will be described with reference to <FIG>. Incidentally, a description of duplicated configurations that are the same as the configurations of the first and second embodiments will be omitted.

As shown in <FIG>, in a capacity control valve V3 of the third embodiment, a pressure sensitive valve member <NUM> is integrally provided with a projection 352f having an annular shape and protruding from a radially outer portion of a side surface 352e on an axially right side of a flange portion 352c to the right in the axial direction. Incidentally, the projection 352f is not limited to being formed in an annular shape, and a plurality of the projections 352f may be evenly disposed in the circumferential direction. In addition, a member separated from the pressure sensitive valve member <NUM> may be fixed to the side surface 352e of the flange portion 352c to form the projection 352f.

Accordingly, in a state where the through-holes 52d of the pressure sensitive valve member <NUM> are closed by the slide valve body <NUM>, a tip surface of the projection 352f is in contact with the side surface 90c of on the axially left side of the slide valve body <NUM> to prevent surface-to-surface contact between the side surface 90c on the axially left side of the slide valve body <NUM> and the side surface 352e of the flange portion 352c of the pressure sensitive valve member <NUM>, so that the slide valve body <NUM> can be easily separated from the pressure sensitive valve member <NUM>, and the responsiveness of the slide valve body <NUM> can be improved.

A capacity control valve according to a fourth embodiment of the present invention will be described with reference to <FIG>. Incidentally, a description of duplicated configurations that are the same as the configurations of the first to third embodiments will be omitted.

As shown in <FIG>, in a capacity control valve V4 of the fourth embodiment, a stopper <NUM> having an annular shape which restricts movement of the slide valve body <NUM> in the opening direction, namely, to the right in the axial direction is fixed to the inner peripheral surface 10d of the valve housing <NUM> on the axially right side of the slide valve body <NUM> in the pressure sensitive chamber <NUM>. Incidentally, the stopper <NUM> is not limited to being formed in an annular shape, and a plurality of the stoppers <NUM> may be evenly disposed in the circumferential direction. In addition, the stopper may be fixed to the outer peripheral surface <NUM> of the base portion 52b of the pressure sensitive valve member <NUM>.

Accordingly, since the stopper <NUM> can specify the amount of movement of the slide valve body <NUM> to the right in the axial direction when the valve is opened, the controllability of the slide valve body <NUM> is high.

The embodiments of the present invention have been described above with reference to the drawings; however, the specific configurations are not limited to the embodiments, and the present invention also includes changes or additions that are made without departing from the scope of the present invention.

For example, in the embodiment, the slide valve body has been described as reciprocating relative to the pressure sensitive valve member in the axial direction; however, the present invention is not limited to the configuration and, for example, the slide valve body may reciprocate relative to the pressure sensitive valve member in the axial direction while rotating and sliding with respect to the pressure sensitive valve member.

In addition, in the embodiments, the thickness dimension L1 of the slide valve body has been described as being larger than the diameter R1 of the through-hole of the pressure sensitive valve member (i.e., L1 > R1), but the present invention is not limited thereto, and a relationship in size between the thickness dimension L1 of the slide valve body and the diameter R1 of the through-hole of the pressure sensitive valve member may be L1 = R1 or L1 < R1. Namely, regarding the closing of the through-holes of the pressure sensitive valve member, the through-holes may not be completely closed by the slide valve body.

In addition, in the embodiments, an example has been described in which the main and auxiliary valve body and the pressure sensitive valve member are formed as separate bodies, but both may be integrally formed.

In addition, the slide valve body may be divided into a plurality of segments in the circumferential direction.

In addition, in the embodiments, the inner peripheral surface of the slide valve body has been described as sliding on the outer peripheral surface of the base portion of the pressure sensitive valve member, but the present invention is not limited to the configuration, and the outer peripheral surface of the slide valve body may slide on the inner peripheral surface 10d of the valve housing <NUM>. Incidentally, in this case, it is preferable that the very small gap formed between the outer peripheral surface of the slide valve body and the inner peripheral surface 10d of the valve housing <NUM> is formed to be smaller than the very small gap formed between the inner peripheral surface of the slide valve body and the outer peripheral surface of the base portion of the pressure sensitive valve member. Furthermore, it is preferable that the slide valve body is made of a material different from that of the valve housing.

In addition, in the pressure sensitive valve member, the base portion and the flange portion may be separately formed.

In addition, the communication passage and the fixed orifice that provide direct communication between the control chamber <NUM> and the suction chamber <NUM> of the variable displacement compressor M may not be provided.

In addition, the auxiliary valve <NUM> may not be provided, and as long as the step portion 51b on the axially right side of the main and auxiliary valve body <NUM> functions as a support member that receives an axial load, a sealing function of the step portion 51b is not necessarily required.

In addition, the pressure sensitive chamber <NUM> may be provided on an axially right side of the main valve chamber <NUM> in which the solenoid <NUM> is provided, and the auxiliary valve chamber <NUM> may be provided on an axially left side of the main valve chamber <NUM>.

In addition, a coil spring may not be used inside the pressure sensitive body <NUM>.

Claim 1:
A capacity control valve (V1 to V4) comprising:
a valve housing (<NUM>) provided with a discharge port (<NUM>) through which a discharge fluid of a discharge pressure (Pd) passes, a suction port (<NUM>) through which a suction fluid of a suction pressure (Ps) passes, and a control port (<NUM>) through which a control fluid of a control pressure (Pc) passes;
a main valve (<NUM>) including a valve body (<NUM>) driven by a solenoid (<NUM>), and a main valve seat (10a) which is provided between the discharge port (<NUM>) and the control port (<NUM>) and with which the valve body (<NUM>) is allowed to come into contact;
a pressure sensitive body (<NUM>) disposed in a pressure sensitive chamber (<NUM>); and
a pressure sensitive valve member (<NUM>, <NUM>) extending from the valve body (<NUM>) to the pressure sensitive chamber (<NUM>) and forming a pressure sensitive valve (<NUM>), together with the pressure sensitive body (<NUM>),
wherein the capacity control valve (V1 to V4) is characterized in that an intermediate communication passage (<NUM>) is formed in the valve body (<NUM>) and in the pressure sensitive valve member (<NUM>, <NUM>), and the control port (<NUM>) and the suction port (<NUM>) are allowed to communicate with each other through the intermediate communication passage (<NUM>) by opening the pressure sensitive valve (<NUM>),
the pressure sensitive valve member (<NUM>, <NUM>) is provided with a through-hole (52d) communicating with the intermediate communication passage (<NUM>) and has a slide valve body (<NUM>, <NUM>, <NUM>) attached thereto such that the slide valve body (<NUM>, <NUM>, <NUM>) slides relative to the pressure sensitive valve member (<NUM>) in the pressure sensitive chamber (<NUM>) to open and close the through-hole (52d), and
the slide valve body (<NUM>, <NUM>, <NUM>) partitions the pressure sensitive chamber (<NUM>) into a Pd side space (S1) on a side of the discharge port (<NUM>) and a Pc side space (S2) on a side of the control port (<NUM>), and a Pd-Pc flow passage (90b, 190b) providing communication between the Pd side space (S1) and the Pc side space (S2) is formed in the slide valve body (<NUM>, <NUM>, <NUM>).