阅读说明：本技术 容量控制阀 (Capacity control valve ) 是由 叶山真弘 福留康平 神崎敏智 高桥涉 白藤啓吾 于 2020-04-02 设计创作，主要内容包括：本发明提供了一种容量控制阀,其能够顺畅地控制阀芯,同时能够将阀芯稳定地保持在最大行程位置。容量控制阀(80)通过对电磁线圈(86)通电,利用磁力使可动铁芯(84)向固定铁芯(82)吸引移动来改变阀芯(51)的位置,其中,一个铁芯(82)在外径侧具备凸部(90),另一个铁芯(84)在内径侧具备凸部(92),它们能够在吸附移动的状态下间隙配合,一个凸部(90)形成为其前端的有效磁力面(90a)比与对置的铁芯(84)的对置面(93)小,且形成为逐渐变细的形状。(The invention provides a capacity control valve, which can smoothly control a valve core and stably keep the valve core at a maximum stroke position. A capacity control valve (80) changes the position of a valve element (51) by energizing an electromagnetic coil (86) and causing a movable iron core (84) to move toward a fixed iron core (82) by magnetic force by attraction, wherein one iron core (82) is provided with a convex part (90) on the outer diameter side, the other iron core (84) is provided with a convex part (92) on the inner diameter side, the convex parts can be in clearance fit in the state of attraction movement, and the effective magnetic force surface (90a) of the front end of one convex part (90) is formed to be smaller than the opposite surface (93) of the opposite iron core (84) and to be tapered.)

1. A capacity control valve in which a solenoid is energized and a movable iron core is attracted to a fixed iron core by magnetic force to change the position of a valve element,

one of the cores has a convex portion on an outer diameter side, and the other core has a convex portion on an inner diameter side, which are capable of clearance-fitting in a state of being moved by suction,

one of the projections is formed in a tapered shape such that an effective magnetic force surface at a tip end thereof is smaller than an opposing surface of the opposing core.

2. The capacity control valve of claim 1,

the tapered inclined surface constituting one of the convex portions is not parallel to the peripheral surface of the other convex portion.

3. The capacity control valve according to claim 1 or 2,

the circumferential surface of the other of the convex portions is parallel to the axial direction of the core.

4. The capacity control valve according to any one of claims 1 to 3, wherein an effective magnetic force surface of a leading end of the convex portion and an opposed surface of the core are formed orthogonally to an axial direction of the core.

5. The capacity control valve according to any one of claims 1 to 4,

the tapered inclined surface of one of the convex portions faces the peripheral surface of the other convex portion.

6. The capacity control valve according to any one of claims 1 to 4,

the tapered inclined surface constituting one of the convex portions is located on a side not opposed to the peripheral surface of the other convex portion.

7. The capacity control valve according to any one of claims 1 to 6,

the capacity control valve is of a normally open type that is opened when the solenoid is not energized.

8. A capacity control valve in which a solenoid is energized and a movable iron core is attracted to a fixed iron core by magnetic force to change the position of a valve element,

one of the cores has a convex portion on an outer diameter side and a concave portion on an inner diameter side, and the other core has a convex portion on an inner diameter side and a concave portion on an outer diameter side, and the cores are in clearance fit in a state of being moved by suction, and are formed such that:

the interval between the tip of one of the projections and the back end of the recess is different from the interval between the tip of the other of the projections and the back end of the recess during suction,

when the magnetic force is not applied, the front end of one of the convex portions and the inner end of the concave portion are located within the effective magnetic force range, and the front end of the other of the convex portions and the inner end of the concave portion are located outside the effective magnetic force range.

Technical Field

The present invention relates to a capacity control valve for variably controlling the capacity of a working fluid, and more particularly, to a capacity control valve for controlling the discharge amount of a variable capacity compressor used in an air conditioning system of an automobile according to pressure.

Background

A variable displacement compressor used in an air conditioning system of an automobile or the like includes: the rotary compressor includes a rotary shaft that is rotationally driven by an engine, a swash plate that is connected to the rotary shaft so that an inclination angle thereof is variable, and a compression piston that is connected to the swash plate. The inclination angle of the swash plate can be continuously changed by appropriately controlling the pressure in the control chamber using a capacity control valve that is opened and closed by electromagnetic force, using the suction pressure Ps of the suction chamber that sucks fluid, the discharge pressure Pd of the discharge chamber that discharges fluid pressurized by the piston, and the control pressure Pc of the control chamber that houses the swash plate.

In the continuous driving of the variable displacement compressor, the displacement control valve is in a form of performing a normal control as follows: the control computer performs energization control, moves the valve body in the axial direction by an electromagnetic force generated by the solenoid, and opens and closes a DC valve provided between a discharge port through which a discharge fluid at a discharge pressure Pd passes and a control port through which a control fluid at a control pressure Pc passes to adjust the control pressure Pc in a control chamber of the variable displacement compressor, or opens and closes a CS valve provided between a suction port through which a suction fluid at a suction pressure Ps passes and the control port through which the control fluid at the control pressure Pc passes to adjust the control pressure Pc in the control chamber of the variable displacement compressor.

In the normal control of the capacity control valve, the pressure in the control chamber of the variable capacity compressor is appropriately controlled, and the amount of displacement of the piston is varied by continuously varying the inclination angle of the swash plate with respect to the rotary shaft, thereby controlling the amount of discharge of the fluid with respect to the discharge chamber and adjusting the air conditioning system to a desired cooling capacity. Further, the valve opening degree of the valve element of the capacity control valve changes in accordance with the electromagnetic force generated by the current applied to the solenoid, and the target value of the pressure difference changes accordingly, so that the control pressure Pc changes.

As described in the prior art of patent document 1, conventionally, the opposed surfaces of two cores, i.e., the movable core and the fixed core, may be flat surfaces orthogonal to the axial direction of the cores. In such a configuration, when the cores approach each other, that is, as the valve element moves from the initial position to the maximum stroke position, the magnetic force acting on the surfaces of the cores facing each other in the axial direction rapidly increases, and thus there is a problem that fine opening and closing adjustment of the valve element is difficult.

Further, the opposed surface of one core may be formed in a conical shape, and the other core may be formed in a shape that fits with the concave-convex clearance of the conical opposed surface. In such a configuration, since the magnetic force acting with a radial component gradually acts between the inclined and parallel opposing surfaces as the valve element moves from the initial position to the maximum stroke position, the magnetic force acting on the opposing surfaces of the cores can be prevented from rapidly increasing, and fine opening and closing adjustment of the valve element can be performed. However, there is a disadvantage that the magnetic force acting between the facing surfaces is small and the axial thrust force for moving the movable core in the axial direction by the electromagnetic force is small, and there is a problem that a large-sized strong solenoid is required to sufficiently secure the axial thrust force.

As an example of patent document 1, the following structure is proposed: one core is formed with a convex portion having a truncated conical shape with a wide plane perpendicular to the axial direction of the core at the tip, in other words, a trapezoidal cross section, and the other core is formed with a concave portion having a shape corresponding to the convex portion.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 2892473 (page 2, FIG. 2)

Disclosure of Invention

Problems to be solved by the invention

In the capacity control valve disclosed as the example of patent document 1, by adopting the above-described configuration, the magnetic force acting between the opposing surfaces can be increased by the plane orthogonal to the axial direction of the core, the axial thrust of the valve body can be reliably held at the maximum stroke position of the valve body, and the magnetic force acting between the opposing surfaces of the cores can be prevented from being rapidly increased as the valve body moves from the initial position to the maximum stroke position, thereby enabling fine opening and closing adjustment of the valve body. However, since the opposed surface of one core is in the shape of a truncated cone, the opposed surface of the other core is in a concave shape complementary to the shape of the truncated cone, and the two cores are in a shape of a concave-convex clearance fit with each other, there are problems as follows: when it is desired to increase the axial thrust at the maximum stroke position of the valve element, the overall structure becomes large, and when an arrangement structure is employed in which the separation distance between the two cores at the maximum stroke position of the valve element is reduced, the magnetic force acting between the inclined opposed surfaces increases due to the approach in the axial direction, and fine opening/closing adjustment of the valve element cannot be smoothly controlled.

The present invention has been made in view of the above problems, and an object thereof is to provide a capacity control valve capable of smoothly controlling a valve element and stably holding the valve element at a maximum stroke position.

Means for solving the problems

In order to solve the above problems, a capacity control valve according to the present invention is a capacity control valve in which a solenoid is energized to move a movable iron core toward a fixed iron core by magnetic force to change the position of a valve body,

one of the cores has a convex portion on an outer diameter side, and the other core has a convex portion on an inner diameter side, which are capable of clearance-fitting in a state of being moved by suction,

one of the projections is formed in a tapered shape such that an effective magnetic force surface at a tip end thereof is smaller than an opposing surface of the opposing core.

Accordingly, since the one convex portion is tapered, the magnetic force acting with the other convex portion having a radial component is small on the tip side thereof, and the magnetic force acting with the other convex portion having a radial component is large on the root side thereof, and therefore, the magnetic force acting between the cores can have the following characteristics in the range from the initial position of the spool to the vicinity of the maximum stroke: the axial thrust is stabilized without being easily affected by the axial approach, and after the maximum stroke of the spool, the effective magnetic force surface at the tip of the projection approaches the opposed surface of the opposed core, the magnetic force acting in the axial direction sharply increases, the axial thrust sharply increases, that is, the region where the axial thrust is stabilized is ensured to be wide, and the axial thrust sharply increases near the maximum stroke. Accordingly, since the axial thrust is small in the range from the initial position to the vicinity of the maximum stroke, the valve body can be smoothly controlled, and the valve body can be stably held at the maximum stroke position with a large axial thrust.

The tapered inclined surface of one of the convex portions may be not parallel to the circumferential surface of the other convex portion.

Accordingly, since the inclined surface of one convex portion is not parallel to the peripheral surface of the other convex portion, the characteristics of the axial thrust can be significantly distinguished between the range from the initial position of the valve body to the vicinity of the maximum stroke and the maximum stroke position side of the valve body.

The circumferential surface of the other projection may be parallel to the axial direction of the core.

Thus, since the magnetic force acting with a radial component between the magnetic force and the one convex portion can be made extremely small, the axial thrust in the range from the initial position of the valve body to the vicinity of the maximum stroke can be efficiently and smoothly increased.

The effective magnetic force surface at the tip of the projection and the facing surface of the core may be formed orthogonally to the axial direction of the core.

Thus, the effective magnetic force surface and the facing surface are formed orthogonal to the axial direction, so that a large magnetic force acting in the axial direction can be ensured when they approach each other, and the axial thrust can be increased rapidly at the maximum stroke position of the valve body.

The tapered inclined surface of one of the convex portions may face the peripheral surface of the other convex portion.

Accordingly, the tapered inclined surface of the one convex portion faces the peripheral surface of the other convex portion, and the root side of the inclined surface of the one convex portion approaches the peripheral surface of the other convex portion after the vicinity of the maximum stroke of the valve body, and a radial component is present therebetween to increase the magnetic force acting, so that the valve body can be stably held at the maximum stroke position.

The tapered inclined surface of one of the convex portions may be located on a side not facing the peripheral surface of the other convex portion.

Thus, the tapered inclined surface of one of the convex portions does not face the peripheral surface of the other convex portion, so that the radial distance between the convex portions does not decrease when the valve body moves, the influence of the magnetic force acting with a radial component therebetween can be minimized, and the axial thrust in the range from the initial position of the valve body to the vicinity of the maximum stroke can be effectively increased smoothly.

Or may be a normally open type that is opened when the electromagnetic coil is not energized.

Thus, even if pressure acts on the valve element from the fluid in the closed state at the time of energization, the axial thrust force is strong at the maximum stroke position of the valve element in the closed state, and therefore the closed state can be reliably maintained.

The capacity control valve of the invention changes the position of a valve core by electrifying an electromagnetic coil and using magnetic force to attract and move a movable iron core to a fixed iron core,

one of the cores has a convex portion on an outer diameter side and a concave portion on an inner diameter side, and the other core has a convex portion on an inner diameter side and a concave portion on an outer diameter side, and the cores are in clearance fit in a state of being moved by suction, and are formed such that:

the interval between the tip of one of the projections and the back end of the recess is different from the interval between the tip of the other of the projections and the back end of the recess during suction,

when the magnetic force is not applied, the front end of one of the convex portions and the inner end of the concave portion are located within the effective magnetic force range, and the front end of the other of the convex portions and the inner end of the concave portion are located outside the effective magnetic force range.

Thus, when the valve element is not attracted, the front end of the one convex portion and the back end of the concave portion, which are located within the effective magnetic force range, move as power. At this time, the power of the front end of the other convex portion and the power of the back end of the concave portion, which are located outside the effective magnetic force range, are not significant in the initial stage, and the other convex portion becomes significant after entering the effective magnetic force range as the one convex portion operates. Therefore, in the range from the initial position of the spool to the vicinity of the maximum stroke, the magnetic force acting between the iron cores can have the following characteristics: the axial thrust becomes smooth while the magnetic force acting in the axial direction sharply increases, the axial thrust sharply increases, that is, the region where the axial thrust becomes smooth is ensured to be wide, and the axial thrust sharply increases in the vicinity of the maximum stroke. Accordingly, since the axial thrust is small in the range from the initial position to the vicinity of the maximum stroke, the valve body can be smoothly controlled, and the valve body can be stably held at the maximum stroke position with a large axial thrust.

Drawings

Fig. 1 is a schematic view showing a structure of a swash plate type variable displacement compressor incorporating a displacement control valve according to an embodiment of the present invention;

fig. 2 is a sectional view showing a case where a CS valve is opened in a non-energized state of a capacity control valve of embodiment 1 of the invention;

fig. 3 is a sectional view showing a case where the CS valve is closed in an energized state (at the time of normal control) of the capacity control valve of embodiment 1;

fig. 4 is an enlarged cross-sectional view of a main portion showing the opposing shape of the movable iron core and the center post of embodiment 1, showing a state in which the CS spool is located at an initial position immediately after energization;

FIG. 5 is also an enlarged cross-sectional view of the main portion showing the state in which the CS spool is in the closed valve position when energized;

fig. 6 is a graph showing a relationship between a stroke of the CS spool and an axial thrust of the movable iron core;

fig. 7 is an enlarged cross-sectional view of a main portion showing the opposing shape of the movable iron core and the center post of embodiment 1, (a) shows a state in which the CS spool is located at an initial position immediately after energization, (b) shows a state in which the CS spool is located at a closed valve position at the time of energization;

fig. 8 is an enlarged cross-sectional view of a main portion showing the opposing shape of the movable iron core and the center post of embodiment 2, showing a state in which the CS spool is located at an initial position immediately after energization;

fig. 9 is also an enlarged cross-sectional view of a main portion showing a state in which the CS spool is in the closed valve position when energized;

fig. 10 is a cross-sectional view showing a state where the CS valve is closed in an energized state (during normal control) of the capacity control valve of embodiment 3.

Detailed Description

Hereinafter, a specific embodiment of the capacity control valve according to the present invention will be described with reference to examples.

Example 1

A capacity control valve according to embodiment 1 will be described with reference to fig. 1 to 7. Hereinafter, the left and right sides when viewed from the front side of fig. 2 will be described as the left and right sides of the capacity control valve.

The capacity control valve V of the present invention is incorporated in a variable capacity compressor M used in an air conditioning system of an automobile or the like, and variably controls the pressure of a working fluid (hereinafter, simply referred to as "fluid") as a refrigerant to control the discharge amount of the variable capacity compressor M, thereby adjusting the air conditioning system to a desired cooling capacity.

First, the variable displacement compressor M will be explained. As shown in fig. 1, the variable displacement compressor M includes a casing 1, and the casing 1 includes a discharge chamber 2, a suction chamber 3, a control chamber 4, and a plurality of cylinders 4 a. The variable displacement compressor M is provided with a communication passage, not shown, for directly communicating the control chamber 4 with the suction chamber 3, and the communication passage is provided with a fixed orifice for adjusting the pressure balance between the suction chamber 3 and the control chamber 4.

Further, the variable displacement compressor M includes: a rotary shaft 5 which is rotationally driven by an unillustrated engine provided outside the housing 1; a swash plate 6 eccentrically connected to the rotary shaft 5 by a hinge mechanism 8 in the control room 4; and a plurality of pistons 7 connected to the swash plate 6 and fitted in the respective cylinders 4a so as to be reciprocatingly movable, wherein the pressure in the control chamber 4 is appropriately controlled by using a capacity control valve V that is driven to open and close by an electromagnetic force, using a suction pressure Ps of the suction chamber 3 into which the fluid is sucked, a discharge pressure Pd of the discharge chamber 2 from which the fluid pressurized by the pistons 7 is discharged, and a control pressure Pc of the control chamber 4 in which the swash plate 6 is accommodated, so that the inclination angle of the swash plate 6 is continuously changed, thereby changing the stroke amount of the pistons 7 to control the discharge amount of the fluid. For convenience of explanation, the displacement control valve V incorporated in the variable displacement compressor M is not shown in fig. 1.

Specifically, the higher the control pressure Pc in the control chamber 4 is, the smaller the inclination angle of the swash plate 6 with respect to the rotary shaft 5 becomes, and the stroke amount of the piston 7 decreases, but when the control pressure Pc reaches a certain or more pressure, the swash plate 6 becomes substantially perpendicular to the rotary shaft 5, that is, a state slightly inclined from perpendicular. At this time, the stroke amount of the piston 7 is minimized, and the pressurization of the fluid in the cylinder 4a by the piston 7 is minimized, whereby the discharge amount of the fluid to the discharge chamber 2 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 4, the larger the inclination angle of the swash plate 6 with respect to the rotary shaft 5, and the larger the stroke amount of the piston 7, but when the control pressure Pc becomes equal to or lower than a certain pressure, the maximum inclination angle of the swash plate 6 with respect to the rotary shaft 5 becomes. At this time, the stroke amount of the piston 7 becomes maximum, and the pressurization of the fluid in the cylinder 4a by the piston 7 becomes maximum, whereby the discharge amount of the fluid to the discharge chamber 2 increases, and the cooling capacity of the air conditioning system becomes maximum.

As shown in fig. 2 and 3, the capacity control valve V incorporated in the variable capacity compressor M adjusts the current to be supplied to the electromagnetic coil 86 constituting the solenoid 80, and controls the opening and closing of the CS valve 50 in the capacity control valve V, thereby controlling the fluid flowing out from the control chamber 4 to the suction chamber 3 to variably control the control pressure Pc in the control chamber 4. Further, the variable displacement compressor M is provided with a communication passage for directly communicating the discharge chamber 2 with the control chamber 4, and the communication passage is provided with a fixed orifice 9 for adjusting the pressure balance between the discharge chamber 2 and the control chamber 4. That is, the discharge fluid at the discharge pressure Pd of the discharge chamber 2 is always supplied to the control chamber 4 via the fixed orifice 9, and the CS valve 50 of the displacement control valve V is closed to increase the control pressure Pc in the control chamber 4.

In the present embodiment, the CS valve 50 is configured by a CS valve body 51 as a valve body and a CS valve seat 10a formed on the inner peripheral surface of the valve housing 10, and the CS valve 50 is opened and closed by the axial left end 51a of the CS valve body 51 coming into contact with or separating from the CS valve seat 10 a.

Next, the structure of the displacement control valve V will be described. As shown in fig. 2 and 3, the capacity control valve V is mainly composed of: a valve housing 10 formed of a metal material or a resin material; a CS spool 51 whose axial left end portion is disposed in the valve housing 10; and a solenoid 80 connected to the valve housing 10 and applying a driving force to the CS spool 51.

As shown in fig. 2 and 3, the CS spool 51 is a columnar body having a constant cross section, and also serves as a rod penetrating the electromagnetic coil 86 of the solenoid 80.

As shown in fig. 2 and 3, the valve housing 10 is formed with: a Ps port 11 as a suction port communicating with the suction chamber 3 of the variable displacement compressor M; and a Pc port 12 as a control port communicating with the control chamber 4 of the variable displacement compressor M.

A valve chamber 20 is formed inside the valve housing 10, and an axial left end portion of the CS spool 51 is disposed in the valve chamber 20 so as to be axially movable back and forth. The Ps port 11 extends radially inward from the outer peripheral surface of the valve housing 10 and communicates with the valve chamber 20, and the Pc port 12 extends axially rightward from the inner peripheral surface of the left end of the valve housing 10 and communicates with the valve chamber 20.

A CS valve seat 10a is formed on the inner peripheral surface of the valve housing 10 at the valve chamber 20-side opening end of the Pc port 12. Further, a guide hole 10b, in which the outer peripheral surface of the CS valve body 51 can slide in a substantially sealed state, is formed on the inner peripheral surface of the valve housing 10 on the solenoid 80 side of the CS valve seat 10a and the valve chamber 20.

The valve housing 10 includes a recess 10c recessed axially leftward from the inner diameter side of the right end in the axial direction, and a flange 82d of a center post 82 serving as a fixed core of the solenoid 80 is inserted and fitted from the axial right direction, so that the solenoid is integrally connected and fixed in a substantially sealed state. Further, the opening end of the guide hole 10b on the solenoid 80 side is formed on the inner diameter side of the bottom surface of the recess 10c of the valve housing 10.

As shown in fig. 2 and 3, the solenoid 80 is mainly composed of: a housing 81 having an opening 81a opened to the left in the axial direction; a substantially cylindrical center post 82 inserted into the opening 81a of the housing 81 from the axial left direction and fixed to the inner diameter side of the housing 81; a CS valve body 51 inserted into the center post 82 and capable of reciprocating in the axial direction, and having an axial left end disposed in the valve housing 10; a movable core 84 into which the axial right end of the CS valve body 51 is fixedly inserted; a coil spring 85 as a spring that is provided between the center post 82 and the movable iron core 84 and biases the movable iron core 84 rightward in the axial direction, which is the valve opening direction of the CS valve 50; and an excitation electromagnetic coil 86 wound around the outside of the center post 82 via a bobbin.

Next, the structure of the center post 82 and the movable iron core 84 will be described with reference to fig. 4. The center post 82 includes a projection 90 that is continuous in a ring shape when viewed from the facing surface formed to protrude toward the side facing the movable core 84. The convex portion 90 is formed on the outer diameter side, has a tapered shape, and includes: a front end surface 90a extending in a direction orthogonal to the axial direction; and an inner peripheral surface 90b continuous with the front end surface 90a and inclined with respect to the axial direction of the center post 82. An opposing surface 91, which is a recessed portion rear end, is formed on the inner diameter side of the root portion of the convex portion 90, and is orthogonal to the axial direction of the center post 82.

The movable core 84 includes a projection 92 that is continuous in a ring shape when viewed from an opposing surface formed to protrude toward a side opposing the center pillar 82. The convex portion 92 is formed on the inner diameter side, has a shape with a uniform width, and includes: a front end surface 92a extending in a direction orthogonal to the axial direction; and an outer peripheral surface 92b continuous with the front end surface 92a and forming a surface parallel to the axial direction of the movable core 84. An opposing surface 93, which is a recessed portion rear end, is formed on the outer diameter side of the root portion of the convex portion 92, and is orthogonal to the axial direction of the movable core 84. The front end surface 90a and the facing surface 91 of the center post 82 are parallel to the facing surface 93 and the front end surface 92a of the movable core 84, respectively.

Further, it is also possible that the outer diameter of the center post 82 is preferably formed in the range of Φ 7.4 to Φ 9.4, more preferably in the range of Φ 7.9 to Φ 8.9. In addition, the inner diameter of the center post 82 may be preferably formed in the range of φ 2.0 to φ 4.0, and more preferably in the range of φ 2.5 to φ 3.5. Further, the inclination angle α of the inner peripheral surface 90b with respect to the axial direction of the center post 82 may be preferably formed in a range of 5 degrees to 15 degrees, more preferably in a range of 8 degrees to 12 degrees, whereby the axial thrust force can be prevented from being reduced, and the range of a thrust leveling portion to be described later can be secured wide.

Further, the outer diameter of the movable iron core 84 may be preferably formed in the range of Φ 7.5 to Φ 9.5, more preferably in the range of Φ 8.0 to Φ 9.0. In addition, the inner diameter of the movable iron core 84 may be preferably formed in a range of Φ 3.3 to Φ 5.3, and more preferably in a range of Φ 3.8 to Φ 4.8. Further, the dimension L2 in the radial direction of the distal end surface 92a of the convex portion 92 of the movable core 84 may preferably be 1.0mm or more, whereby the thrust in the axial direction can be prevented from being reduced. Further, the dimension L1 in the radial direction of the minimum gap between the outer peripheral surface 92b of the convex portion 92 of the movable core 84 and the inner peripheral surface 90b of the convex portion 90 of the center post 82 may be formed preferably in the range of 0.1mm to 0.3mm, more preferably in the range of 0.15mm to 0.25mm, whereby it is possible to prevent the thrust force in the axial direction from decreasing and to suppress the thrust force from decreasing in a state where the CS valve body 51 is located at the initial position immediately after the energization.

Next, the operation of the capacity control valve V, mainly the opening and closing operation of the CS valve 50, will be described.

First, the non-energized state of the displacement control valve V will be described. As shown in fig. 2, in the non-energized state of the capacity control valve V, the movable core 84 is pushed rightward in the axial direction by the biasing force of the coil spring 85 constituting the solenoid 80, whereby the CS valve body 51 moves rightward in the axial direction, the left end 51a in the axial direction of the CS valve body 51 is separated from the CS valve seat 10a formed on the inner circumferential surface of the valve housing 10, and the CS valve 50 is opened. Fig. 2 shows a state in which the CS spool 51 is located at the initial position.

As shown in fig. 3, in the energized state of the capacity control valve V (i.e., in the normal control, so-called duty control), when a current is applied to the solenoid 80, the movable core 84 is pulled toward the center post 82 side, i.e., the axial left side, and the CS valve body 51 fixed to the movable core 84 is moved together in the axial left direction, whereby the axial left end 51a of the CS valve body 51 is seated on the CS valve seat 10a of the valve housing 10, and the CS valve 50 is closed. Fig. 3 shows a state in which the CS spool 51 moves to the maximum stroke position and the CS valve 50 is closed.

Fig. 4 shows a state in which the CS spool 51 is at the initial position immediately after the energization, and fig. 5 shows a state in which the CS spool 51 moves to the valve-closing position when the energization is performed at the maximum current value. As shown in fig. 4, since the convex portion 90 of the center post 82 has a tapered shape, the convex portion 92 of the movable core 84 is radially separated from the convex portion 90 at the tip end side thereof, and the influence of the magnetic force acting with a radial component therebetween is extremely small. In this way, the convex portion 90 of the center post 82 and the convex portion 92 of the movable core 84 can be in clearance fit in a state where the movable core 84 is attracted and moved toward the center post 82 by the energization. Fig. 4 and 5 conceptually show the magnetic lines in the initial position and the valve-closing position of the CS spool 51.

Further, since the tapered inner peripheral surface 90b of the convex portion 90 constituting the center post 82 and the outer peripheral surface 92b of the convex portion 92 of the movable core 84 parallel to the axial direction are at different angles, the magnetic force acting with a radial component therebetween in the range from the initial position of the CS valve body 51 to just before the valve-closing position is less increased.

Further, as an effect of the tapered shape of the convex portion 90 of the center pole 82, the cross-sectional area of the center pole 82 on the root side is larger than that on the tip side in addition to the relationship of the separation distance between the convex portion 90 and the convex portion 92, and therefore, the magnetic force acting with a radial component between the magnetic force and the convex portion 92 of the movable core 84 is reduced on the tip side.

Further, since the outer peripheral surface 92b of the convex portion 92 of the movable core 84 forms a surface parallel to the axial direction of the movable core 84, the magnetic force acting with a radial component between the magnetic force and the convex portion 90 of the center pillar 82 can be made extremely small, and the axial thrust can be increased smoothly and efficiently in a wide range from the initial position of the CS valve body 51 to just before the valve closing position (see fig. 6). For reference, when the outer peripheral surface 92b is formed obliquely in parallel with the inclined inner peripheral surface 90b, its characteristics are: as the movable iron core 84 moves in the valve closing direction, the magnetic flux passing through the outer peripheral surface 92b and the inner peripheral surface 90b increases, and the region where the axial thrust is smooth becomes narrower than in the embodiment 1, and the axial thrust gradually increases.

When the CS valve body 51 moves to the valve-closing position, the front end surface 90a, which is the effective magnetic force surface of the front end of the convex portion 90 of the center post 82, approaches the facing surface 93 of the movable core 84, and the facing surface 91 of the center post 82 approaches the front end surface 92a of the convex portion 92 of the movable core 84, so that the magnetic force acting in the axial direction between the center post 82 and the movable core 84 rapidly increases. In other words, the magnetic force acting in the axial direction between the center post 82 and the movable iron core 84 does not increase rapidly before the CS valve body 51 moves to the valve-closing position, that is, in the range from the initial position of the CS valve body 51 to just before the valve-closing position.

Further, since the front end surface 90a, which is the effective magnetic surface of the front end of the convex portion 90 of the center post 82, and the facing surface 93 of the movable core 84, and the front end surface 92a, which is the effective magnetic surface of the front end of the convex portion 92 of the center post 82 and the movable core 84, are formed orthogonal to the axial directions of the center post 82 and the movable core 84, respectively, a large magnetic force acting in the axial direction when they approach each other can be ensured, and the axial thrust of the movable core 84 can be effectively and rapidly increased at the valve-closed position of the CS valve 50.

Further, since the facing surface 93 of the movable core 84 has a larger facing area than the front end surface 90a, which is the effective magnetic surface of the front end of the convex portion 90 of the center post 82, and the facing surface 91 of the center post 82 has a larger facing area than the front end surface 92a, which is the effective magnetic surface of the front end of the convex portion 92 of the movable core 84, magnetic flux easily passes through, and a large attractive force due to magnetic force can be secured between these facing surfaces. Further, the tip of the convex portion 92 of the movable core 84 extends to the inner side of the inner diameter of the center post 82, and the facing surface 91 of the center post 82 has a smaller facing area than the tip end surface 92a, which is the effective magnetic surface of the tip of the convex portion 92 of the movable core 84.

By adopting the above-described configuration, as can be seen from the graph showing the relationship between the stroke of the CS spool 51 and the axial thrust of the movable core 84 shown in fig. 6, the characteristic is a shape in which the asymptotes are close to hyperbolas, which are the x axis and the y axis, respectively. Further, a thrust stabilizing portion in which a state in which the axial thrust is small smoothly progresses in a range from the initial position of the CS spool 51 to just before the valve-closing position is shown, and the CS spool 51 can be smoothly controlled and can be stably held with a large axial thrust in the valve-closing position of the CS spool 51. That is, the closed state of the CS valve 50 on which the control pressure Pc acts can be reliably maintained.

Further, since the tapered inner peripheral surface 90b of the convex portion 90 constituting the center pillar 82 is located on the side facing the outer peripheral surface 92b of the convex portion 92 of the movable core 84, as shown in fig. 3, the convex portion 92 of the movable core 84 approaches the root portion side of the convex portion 90 of the center pillar 82 in the radial direction in the process of moving the CS valve body 51 to the valve closing position, and the magnetic force acting with a radial component therebetween gradually rises due to the axial approach. That is, the magnetic force acting with a radial component assists the axial thrust force after the vicinity of the valve-closing position.

The capacity control valve V in the above embodiment is of a normally open type that is opened when the solenoid 86 is not energized. As described above, in the closed state at the time of energization, even if pressure acts on the CS spool 51 from the fluid, the axial thrust force is strong at the valve-closed position of the CS spool 51 in the closed state, and therefore the closed state can be reliably maintained. Further, when the displacement control valve V of embodiment 1 is in the closed state, the pressure acting on the Pc port 12 is increased with time due to the influence of the discharge pressure Pd, and therefore, it is also useful.

As shown in fig. 7(b), in the suction state, that is, in the state where the CS valve body 51 is in the valve-closed position, a distance L8 between the front end surface 92a of the convex portion 92 of the movable core 84 and the facing surface 91 of the center post 82 is different from a distance L7 between the front end surface 90a of the convex portion 90 of the center post 82 and the facing surface 93 of the movable core 84.

As shown in fig. 7(a), when the CS valve body 51 is not attracted, that is, in a state where the CS valve body 51 is at the initial position, the front end surface 92a of the convex portion 92 of the movable core 84 and the facing surface 91 of the center post 82 are located within the effective magnetic force range E. That is, the distance L6 between the front end surface 92a of the convex portion 92 of the movable core 84 and the facing surface 91 of the center pillar 82 is shorter than the effective magnetic force range E.

When not attracting, the front end surface 90a of the convex portion 90 of the center post 82 and the facing surface 93 of the movable core 84 are located outside the effective magnetic force range E. That is, the distance L5 between the front end surface 90a of the convex portion 90 of the center post 82 and the facing surface 93 of the movable core 84 is formed to be longer than the effective magnetic force range E.

Thus, the CS valve body 51 is moved by the power of the end surface 92a of the convex portion 92 of the movable core 84 and the facing surface 91 of the center post 82 which are located within the effective magnetic force range E during non-attraction. At this time, the power of the front end surface 90a of the convex portion 90 of the center pillar 82 and the opposed surface 93 of the movable core 84 located outside the effective magnetic force range E is not significant in the initial stage, and the front end surface 90a of the convex portion 90 of the center pillar 82 and the opposed surface 93 of the movable core 84 become significant after entering the effective magnetic force range E with the operation of the front end surface 92a of the convex portion 92 of the movable core 84 and the opposed surface 91 of the center pillar 82. Therefore, the magnetic force acting between the center post 82 and the movable iron core 84 in the range from the initial position of the CS spool 51 to the vicinity of the maximum stroke can have the following characteristics: the axial thrust becomes smooth while the magnetic force acting in the axial direction sharply increases, the axial thrust sharply increases, that is, the region where the axial thrust becomes smooth is ensured to be wide, and the axial thrust sharply increases in the vicinity of the maximum stroke. Accordingly, since the axial thrust is small in the range from the initial position to the vicinity of the maximum stroke, the CS spool 51 can be smoothly controlled, and the CS spool 51 can be stably held at the maximum stroke position with a large axial thrust. In the present embodiment, the effective magnetic force range E shows the axial distance at which the magnetic attractive force equal to or greater than a predetermined value is generated.

Example 2

The displacement control valve according to embodiment 2 will be described with reference to fig. 8 and 9. Note that, the same structure as that of embodiment 1 described above will not be described repeatedly.

As shown in fig. 8, the center post 94 includes a projection 95 formed to project toward the side facing the movable core 84. The convex portion 95 is formed on the outer diameter side, has a tapered shape, and includes an outer peripheral surface 95b that extends over the distal end surface 95a and is inclined with respect to the axial direction of the center post 82. The inner peripheral surface 95c of the projection 95 forms a surface parallel to the axial direction of the center post 94. Further, an opposed surface 96, which is a recess rear end, is formed on the inner diameter side of the root portion of the convex portion 95, and is orthogonal to the axial direction of the center post 82.

In addition, the inclination angle β of the outer peripheral surface 95b with respect to the axial direction of the center post 94 may be formed preferably in the range of 15 degrees to 25 degrees, more preferably in the range of 18 degrees to 22 degrees, whereby the axial thrust force can be prevented from becoming small and the range of the thrust force stabilizing portion can be secured wide.

As shown in fig. 8 and 9, since the convex portion 95 of the center post 94 is tapered, the cross-sectional area is larger on the root side than on the tip side, and the magnetic force acting with a radial component between the convex portion 92 of the movable core 84 is smaller on the tip side and larger on the root side. Therefore, in the range from the initial position of the CS spool 51 to just before the valve-closing position, the magnetic force acting between the center post 94 and the movable core 84 changes while keeping a small state, and the axial thrust force does not increase rapidly and becomes smooth.

When the CS valve body 51 moves to the valve-closing position side, the front end surface 95a, which is an effective magnetic force surface of the front end of the convex portion 95 of the center post 94, approaches the facing surface 93 of the movable core 84, and the facing surface 96 of the center post 94 approaches the front end surface 92a of the convex portion 92 of the movable core 84, so that the magnetic force acting in the axial direction between the center post 94 and the movable core 84 rapidly increases.

Further, an outer peripheral surface 95b of the projection 95 constituting the center post 94, which is tapered, is located on a side not facing the outer peripheral surface 92b of the projection 92 of the movable core 84, and an inner peripheral surface 95c of the projection 95 of the center post 94 forms a surface parallel to the axial direction of the center post 94. Thus, when the CS valve body 51 moves, the inner peripheral surface 95c of the convex portion 95 of the center post 94 and the outer peripheral surface 92b of the convex portion 92 of the movable core 84, which are parallel to each other, do not come close to each other in the radial direction, and the influence of the magnetic force acting with a radial component therebetween can be minimized, and the axial thrust can be efficiently and smoothly increased in the range from the initial position of the CS valve body 51 to just before the valve-closing position.

Further, as shown in fig. 9, when the CS valve body 51 moves to the valve-closing position, the cross-sectional area gradually increases on the root side of the convex portion 95 of the center post 94, and therefore suppression of magnetic flux due to magnetic saturation gradually decreases, and therefore the magnetic force acting with a radial component therebetween gradually increases due to the axial approach. That is, the magnetic force acting with a radial component assists the axial thrust force after the vicinity of the valve-closing position.

Example 3

The displacement control valve according to example 3 will be described with reference to fig. 10. Note that, the same structure as that of embodiment 1 described above will not be described repeatedly.

In the non-energized state, the capacity control valve V2 presses the movable core 84 in the axial direction rightward by the biasing force of the coil spring 85, whereby the CS valve body 151 moves in the axial direction rightward, the axial direction right side surface of the large diameter portion 151a of the CS valve body 151 is seated on the CS valve seat 110a, and the CS valve 150 is closed. In the energized state (i.e., during normal control, so-called duty control), current is applied to the solenoid 80, so that the movable core 84 is pulled toward the center post 82 side, i.e., toward the axial left side, and the CS spool 151 fixed to the movable core 84 is moved together in the axial left direction, whereby the axial right side surface of the large diameter portion 151a of the CS spool 151 is separated from the CS valve seat 110a of the valve housing 110, and the CS valve 150 is opened. Fig. 10 shows a state in which the CS valve body 151 has moved to the maximum stroke position and the CS valve 150 is opened.

Thus, the capacity control valve V2 is configured as a normally closed type in which the CS valve body 151 is biased in the valve closing direction of the CS valve 150 by the coil spring 85, and therefore, in the open state at the time of energization, the CS valve body 151 is held in position only by the electromagnetic force against the coil spring 85 as described above. The capacity control valve V2 of the present invention has the shape of the movable core 84 and the center post 82 facing each other as described above, and therefore, in the valve-open position of the CS valve body 151, the axial thrust is strong, and therefore, the valve-open position of the CS valve body 151 can be reliably maintained.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations are not limited to these embodiments, and modifications and additions may be made without departing from the spirit of the invention.

For example, in the above-described embodiment, the two cores, i.e., the movable core 84 and the convex portion 90 of the center post 82 in the center post 82, are formed in the tapered shape, but the present invention is not limited thereto, and the movable core may be formed in the tapered shape, the inner peripheral surface and the outer peripheral surface of the center post may be formed as the surfaces parallel to the axial direction, or both the movable core and the center post may be formed in the tapered shape. In addition, in the case where both the movable core and the center post are tapered shapes, they may be inclined at different angles from each other with respect to the axial direction.

The front end surface 90a, which is the effective magnetic surface of the front end of the protruding portion 90 of the center post 82, the facing surface 93 of the movable core 84, the facing surface 91 of the center post 82, and the front end surface 92a, which is the effective magnetic surface of the front end of the protruding portion 92 of the movable core 84, are not limited to the structures that are formed at angles orthogonal to the axial direction, and may be slightly inclined with respect to the orthogonal direction.

The inner circumferential surface 90b, which is an inclined surface having a tapered shape, of the convex portion 90 constituting the center post 82 and the outer circumferential surface 95b, which is an inclined surface having a tapered shape, of the convex portion 95 constituting the center post 94 are not limited to flat surfaces, and may have curved surfaces.

Further, a communication passage and a fixed orifice that directly communicate the control chamber 4 and the suction chamber 3 of the variable displacement compressor M may not be provided.

The displacement control valve V, V2 is configured to adjust the control pressure Pc in the control chamber 4 by performing the opening/closing operation of the CS valve, but is not limited to this, and may be a displacement control valve that performs the following normal control: the control pressure Pc of the control chamber of the variable displacement compressor is adjusted by opening and closing a DC valve provided between a discharge port through which the discharge fluid at the discharge pressure Pd passes and a control port through which the control fluid at the control pressure Pc passes.

Description of the symbols

1: a housing; 2: a discharge chamber; 3: a suction chamber; 4 a: a cylinder; 4: a control room; 5: a rotating shaft; 6: a sloping plate; 7: a piston; 9: a fixed orifice; 10: a valve housing; 10 a: a valve seat; 50: a CS valve; 51 a: to the left end of the shaft; 51: a CS valve core; 80: a solenoid; 82: a central column (fixed iron core); 84: a movable iron core; 85: a coil spring; 86: an electromagnetic coil; 90: a convex portion; 90 a: front end face (effective magnetic face); 90 b: an inner peripheral surface; 91: an opposed surface (a concave portion inner end); 92 b: an outer peripheral surface; 92 a: front end face (effective magnetic face); 92: a convex portion; 93: an opposed surface (a concave portion inner end); 94: a central column (fixed iron core); 95: a convex portion; 95 a: front end face (effective magnetic face); 95 b: an outer peripheral surface; 95 c: an inner peripheral surface; 96: an opposed surface (a concave portion inner end); 110: a valve housing; 110 a: a valve seat; 150: a CS valve; 151: a CS valve core; e: the effective magnetic force range; m: a variable capacity type compressor; v: a capacity control valve; v2: a capacity control valve.