JP2012036812A - Control valve for variable displacement compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control valve for a variable displacement compressor, effectively inhibiting wear, erosion and the like of the inner peripheral edge of a valve port.SOLUTION: The control valve for the variable displacement compressor includes: a valve stem 15 having a valve element part 15a; and a valve body 20 having a guide hole 19 in which the valve rod 15 is inserted fittingly and slidably, and a valve chamber 21 provided with the valve port 22 which the valve element part 15a contacts to and separates from, and provided with a discharge pressure refrigerant lead-in opening 25 on an upstream side of the valve port 22 and a refrigerant lead-out opening (24, 26) on a downstream side of the valve port 22 in communication with the crank chamber of the compressor. For preventing a refrigerant from being split when leaving the valve port 22, the refrigerant lead-out opening is composed of a single lead-out chamber 24 provided immediately downstream of the valve port 22 and a plurality of communication holes 26 proving communication between the lead-out chamber 24 and the outside of the valve.

Description

  The present invention relates to a control valve for a variable displacement compressor used in a car air conditioner and the like, and in particular, a control valve for a variable displacement compressor that can prevent a valve rod from causing a malfunction and is excellent in assemblability and the like. About.

  In general, a control valve for a variable displacement compressor used in a car air conditioner or the like introduces a refrigerant having a discharge pressure Pd from a compressor (discharge chamber) in order to adjust a pressure Pc in a crank chamber of the compressor. The refrigerant having the discharge pressure Pd is squeezed out and led to the crank chamber, and the derivation amount (throttle amount) to the crank chamber is controlled in accordance with the suction pressure Ps of the compressor. As a configuration, for example, as seen in the following Patent Document 1 and the like, a valve stem having a valve body portion, a guide hole in which the valve rod is slidably inserted, and a valve port in which the valve body portion is contacted and separated And a discharge pressure refrigerant introduction port (Pd port) for introducing a refrigerant having a discharge pressure from the compressor upstream from the valve port, and a downstream side from the valve port. And a refrigerant outlet port (Pc port) communicating with the crank chamber of the compressor. A valve main body provided with a coil, a cylindrical stator disposed on the inner peripheral side of the coil, an attractor fixed to the stator, and slidably disposed vertically below the attractor And an electromagnetic actuator having a guide pipe into which the plunger is slidably fitted, and formed above the attractor. A pressure sensing chamber into which suction pressure is introduced from a compressor via a suction pressure introduction port (Ps port), and a pressure sensitive response member that urges the valve rod in the valve opening direction in accordance with the pressure in the pressure sensing chamber; And a valve closing spring for urging the valve rod in the valve closing direction.

  In the control valve having such a configuration, when the coil of the electromagnetic actuator is energized, the plunger is attracted to the attractor, and accordingly, the valve rod is closed so as to follow the plunger by the biasing force of the valve closing spring. It can be moved in the direction. On the other hand, the refrigerant having the suction pressure Ps introduced from the compressor through the Ps port enters the pressure sensing chamber through a gap formed between the plunger and the guide pipe disposed on the outer periphery thereof. The pressure-responsive member (for example, a bellows device) is expanded and contracted according to the pressure in the pressure-sensitive chamber (suction pressure Ps) (contracts when the suction pressure Ps is high and expands when the pressure is low), and the displacement (biasing force) is It is transmitted to the valve stem, thereby adjusting the valve opening. That is, the valve opening is determined by the suction force of the plunger by the suction element, the urging force of the pressure-sensitive response member, and the urging force by the plunger spring (valve opening spring) and the valve closing spring. Accordingly, the discharge amount Pd introduced into the valve chamber from the Pd port is adjusted to the refrigerant outlet side, that is, the amount (throttle amount) to the crank chamber, thereby controlling the pressure Pc in the crank chamber.

  FIG. 6 shows an example of the structure of the lower part of the valve stem and the valve body in the control valve as described above (see also Patent Document 2 below). The valve stem 15 of the control valve 1 ′ shown in FIG. 6 includes, in order from the bottom, a lower fitting portion 15b, a valve body portion 15a having a larger diameter than the lower fitting portion 15b, a small diameter portion 15c, an upper fitting portion 15d, and the like. In addition, the valve body 20 is configured such that the valve body 15a is in contact with the guide holes 19A and 19B into which the valve rod 15 (the upper insertion portion 15d and the lower insertion portion 15b) is slidably inserted. And a valve chamber 21 provided with a valve seat (valve port) 22 to be separated, and discharge pressure refrigerant introduction for introducing refrigerant of discharge pressure Pd from the compressor upstream (downward) from the valve port 22. A port (Pd port) 25 is provided, and for example, four Pc lateral holes 29 that form a refrigerant outlet port (Pc port) communicating with the crank chamber of the compressor on the downstream side (upper side) of the valve port 22. Is provided. These four Pc lateral holes 29 are radially outward with an equal angle (90 degrees) with respect to the valve port 22, as can be understood by referring to FIG. 7 showing a cross section taken along the line ZZ in FIG. It is formed radially toward the direction.

JP 2003-172256 A Japanese Patent Application No. 2009-028080

  In the control valve 1 ′ having the structure as shown in FIGS. 6 and 7, the following problem may occur. That is, when the refrigerant flowing from the discharge pressure refrigerant introduction port (Pd port) 25 → the valve chamber 21 → the valve port 22 (the gap between the valve body portion 15a) exits the valve port 22, four refrigerants for Pc are used. Since the flow is divided into the horizontal holes 29, the refrigerant is present in the vicinity of the center of the four Pc horizontal holes 29 in the inner peripheral edge of the valve port 22 (part indicated by a broken line E in FIG. 7). Therefore, erosion (wear / erosion) is likely to occur in the E portion.

  If such wear or erosion occurs in the valve seat of the valve port 22 (the part where the valve body 15a contacts), so-called valve leakage occurs, and the pressure Pc cannot be properly controlled, and the reliability of the control valve is improved. descend.

  Further, in the control valve 1 ′ having the above-described structure, foreign matter (the wear / erosion component, cutting remaining from the time of machining and assembly) is formed in the sliding surface gap α between the guide hole 19A and the upper fitting portion 15d of the valve stem 15. There is a tendency to cause malfunction such as polishing scraps, abrasives, wear due to sliding friction, dust from the outside, etc., and valve stem 15 locking.

  In addition, the pressure loss may change greatly depending on the mounting angle of the control valve with respect to the compressor. That is, since the Pc lateral hole 29 is provided at an angle of 90 ° around the central axis of the valve body 20, the control valve is arranged so that the Pc lateral hole 29 faces the refrigerant passage P ′ on the compressor side. There is a problem that it takes time and effort to adjust the mounting angle (angle around the central axis D) with respect to the compressor 1 ', so that the mounting hole H' must be mounted.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to effectively suppress wear and erosion of the inner peripheral edge of the valve opening, and hardly cause valve leakage, valve rod malfunction, and the like. Another object of the present invention is to provide a control valve for a variable displacement compressor.

  In order to achieve the above object, a control valve for a variable displacement compressor according to the present invention basically includes a valve stem having a valve body portion, and a guide hole into which the valve stem is slidably inserted. A valve chamber provided with a valve port for contacting and separating the valve body portion, and provided with a discharge pressure refrigerant introduction port for introducing refrigerant at a discharge pressure from the compressor upstream from the valve port, A valve body provided with a refrigerant outlet opening communicating with the crank chamber of the compressor downstream from the valve opening; an electromagnetic actuator having a plunger for moving the valve stem in a valve closing direction; and the compressor A pressure-sensitive chamber into which the suction pressure is introduced, and a pressure-sensitive response member that presses the valve rod in the valve-opening direction in accordance with the pressure in the pressure-sensitive chamber, and the refrigerant is not divided when leaving the valve port As described above, the refrigerant outlet port has a single outlet chamber provided immediately downstream of the valve port, It is characterized in that the outlet chamber and the valve outside is composed of a communication hole communicating.

A plurality of the communication holes are preferably provided.
In another preferred embodiment, a partition wall portion in which the guide hole is formed above the valve port in the valve body is provided, the outlet chamber is provided between the partition wall portion and the valve port, and the communication hole Is provided on the opposite side of the guide hole across the lead-out chamber.

  In another preferred embodiment, the refrigerant is flowed from the valve port through the outlet chamber and the communication hole so as to draw a reverse U shape in a side view.

  In the control valve for a variable displacement compressor according to the present invention, the refrigerant is led from the valve port to the single outlet chamber and from the outlet chamber to the crank chamber of the compressor through the communication hole. When leaving the mouth, it is not diverted, and the refrigerant flows evenly along the entire inner periphery of the valve mouth. Therefore, local wear and erosion of the inner peripheral edge of the valve port can be effectively suppressed, and valve leakage, valve rod malfunction, and the like are less likely to occur.

  Further, the communication hole is provided on the opposite side of the guide hole formed in the partition wall across the outlet chamber, and the refrigerant flows from the valve port through the outlet chamber and the communication hole so as to draw a reverse U shape in side view. This makes it difficult for foreign matter to enter the sliding surface gap between the guide hole and the upper fitting insertion portion of the valve stem, thereby making it difficult to cause malfunction such as locking of the valve stem.

The longitudinal cross-sectional view which shows one Example of the control valve for variable displacement compressors which concerns on this invention. The expanded sectional view which shows the lower part of the control valve shown by FIG. XX arrow sectional drawing of FIG. FIG. 6 is a cross-sectional view taken along arrow YY in FIG. The figure which is provided for valve assembly description of the Example shown by FIG. The expanded sectional view which shows the lower part of the conventional control valve for variable displacement compressors. ZZ arrow sectional drawing of FIG.

Hereinafter, embodiments of a control valve for a variable displacement compressor of the present invention will be described with reference to the drawings.
1 is a longitudinal sectional view showing an embodiment of a control valve for a variable displacement compressor according to the present invention, FIG. 2 is an enlarged sectional view showing a lower portion of the control valve shown in FIG. 1, and FIG. FIG. 2 is a cross-sectional view taken along line XX.

  The illustrated control valve 1 includes an electromagnetic actuator 30, a valve main body 20, a valve rod 15 slidably fitted in the valve main body 20, and a bellows device 40 as a pressure-sensitive response member. Yes.

  The electromagnetic actuator 30 includes a coil 32 for energizing excitation, a connector head 31 having a power connector portion 31A attached to the upper side of the coil 32, and a cylindrical attractor 34 ( A stator), a stepped guide pipe 35 whose upper end is joined to the outer periphery (step part) of the lower end of the suction element 34 by TIG welding, and vertically below the inner side of the guide pipe 35 below the suction element 34. A plunger 37 slidably disposed on the coil 32, a stepped cylindrical housing 60 externally attached to the coil 32 and the connector head 31, and a lower end portion of the housing 60 and the stepped guide pipe 35. A holder 50 is provided for fixing them to the upper part of the valve body 20.

  An adjusting screw 65 with a hexagonal hole is screwed onto the upper portion of the suction element 34, and a tension bar 33 slidably fitted into the suction element 34 and the plunger 37 is fitted to the lower end surface of the adjustment screw 65. The upper end surface is brought into contact.

  The valve body 20 has a valve chamber 21 provided with a valve seat (valve port) 22 with which the valve body 15a of the valve stem 15 contacts and separates, and an outer peripheral portion of the valve chamber 21 (below the valve port 22). Are provided with a plurality of discharge pressure refrigerant introduction ports 25 for introducing refrigerant having a discharge pressure Pd from the compressor, and a convex stopper portion for regulating the lowest position of the plunger 37 above the valve port 22. 28 is fixed by press fitting or the like. The convex stopper portion 28 also serves as a partition wall that partitions the inside of the valve body 20, so that the refrigerant is not divided between the convex stopper portion 28 and the valve port 22 when the refrigerant exits the valve port 22. In addition, a single outlet chamber 24 is provided, and four communication holes 26 opened at the lower portion of the valve body 20 at the lower end surface of the outlet chamber 24 and the valve body 20 are equiangularly (90 Degrees) at intervals.

  An insertion hole 13 for inserting the valve rod 15 during assembly is provided at the center of the lower end portion of the valve body 20, and a lower end portion (lower fitting insertion portion) of the valve rod 15 described later is provided in the insertion hole 13. ) A bottomed stepped cylindrical stopper-shaped guide member 12 into which 15b is slidably inserted is fixed by press fitting or the like. Further, a suction pressure introduction port (Ps port) 27 and a suction pressure introduction chamber 23 are provided above the convex stopper portion 28 in the valve body 20.

  The lead-out chamber 24 and the four communication holes 26 constitute a refrigerant lead-out port for guiding the refrigerant (pressure Pc) flowing from the valve chamber 21 through the valve port 22 to the crank chamber. The hole 26 is provided on the opposite side of the guide hole 19 formed in the convex stopper portion 28 with the lead-out chamber 24 interposed therebetween, and the refrigerant is laterally passed from the valve port 22 through the lead-out chamber 24 and the communication hole 26. It will be swept like drawing a reverse U-shape.

  The valve rod 15 includes a lower rod-shaped member 15A that is slidably inserted into a guide hole 19 formed in the convex stopper portion 28, and an upper convex member 15B that is disposed above the lower rod-shaped member 15A. The lower bar-shaped member 15A includes, in order from the bottom, a lower insertion portion 15b, a valve body portion 15a having a larger diameter than the lower insertion portion 15b, a small diameter portion 15c, an upper insertion portion 15d, and a mushroom shape. The upper convex member 15B includes a small-diameter rod-shaped portion 15f, a large-diameter portion 15g, and a hook-shaped spring receiving portion 15h in order from the top. Further, a pressure equalizing hole 18 having a T-shaped cross section is formed inside the valve rod 15 composed of the lower rod-shaped member 15A and the upper convex member 15B.

  On the other hand, in order to directly connect the plunger 37 and the valve stem 15 (lower rod-like member 15A), a bottomed cylindrical connecting cylinder 52 made of an elastic thin plate material is provided. The bellows device 40 and the upper convex portion 15B of the valve rod 15 are accommodated.

  Specifically, the upper part of the connecting cylinder 52 is caulked and fixed to an annular groove 37a formed on the outer periphery of the lower part of the plunger 37 (caulking part 52a), and the center of the bottom part 52b is shown in FIGS. As shown in FIG. 4, a quadrangular truncated cone-shaped elastic locking piece 53 that is bent inward (upward) from the bottom 52 b is provided. As shown in FIGS. 5 (a) → (b) → (c), this elastic locking piece 53 is pushed up from the lower side by a mushroom-like head portion 15 e of the lower rod-shaped member 15 </ b> A of the valve rod 15. After passing through the mushroom-shaped head 15e pushed outward in the radial direction and passing the mushroom-shaped head 15e, the original mushroom-shaped head 15e is restored to the original quadrant truncated cone shape by its elasticity. It is designed to be locked. By locking the mushroom-shaped head 15e of the elastic locking piece 53, the plunger 37 and the valve stem 15 are directly connected via the connecting cylinder 52, and they move up and down integrally.

  Further, on the bottom 52b of the connecting cylinder 52 and the mushroom head 15e, the hook-shaped spring receiving portion 15h and the large diameter portion 15g of the lower convex portion 15B are brought into contact.

  The bellows device 40 disposed in the connecting cylinder 52 includes a bellows 41 as a pressure-sensitive response member, a reverse convex upper stopper 42, a reverse concave lower stopper 43, a compression coil spring 44, and a cylindrical shape. A space formed between the connecting cylinder 52 and the bellows 41 is provided with a spring receiver 48 and the like, and serves as a pressure sensitive chamber 45. The upper end surface (upper stopper 42) of the bellows device 40 is brought into contact with the tension bar 33, and the lower stopper 43 is inserted into and brought into contact with the small-diameter bar-like portion 15f of the upper convex member 15B.

  A compression coil spring 46 that supports the bellows 41 and urges the valve stem 15 in the valve opening direction (downward) between the lower stopper 43 and the flange-shaped spring receiving portion 15h of the upper convex member 15B. Is being disguised.

  In the control valve 1 configured as described above, when the plunger 37 is attracted to the attractor 34 (when energized), the valve rod 15 is forcibly pulled by the plunger 37 via the connecting cylinder 52 in the valve closing direction. On the other hand, the suction pressure Ps introduced from the compressor into the suction pressure introduction port 27 is introduced into the pressure sensing chamber 45 through the gaps between the members, and the bellows device 40 (inside the vacuum pressure) is connected to the pressure sensing chamber 45. The expansion / contraction displacement (contraction occurs when the suction pressure Ps is high and the expansion occurs when the suction pressure Ps is low) according to the pressure (suction pressure Ps), and the displacement is transmitted to the valve stem 15, thereby adjusting the valve opening. That is, the valve opening degree is determined by the suction force of the plunger 37 by the suction element 34, the urging force of the bellows device 40, and the urging force of the compression coil spring 46, and the discharge pressure refrigerant according to the valve opening degree. The discharge amount Pd introduced into the valve chamber 21 from the inlet 25 is adjusted to the refrigerant outlet 26 side, that is, the amount (throttle amount) to the crank chamber, thereby controlling the pressure Pc in the crank chamber.

  As described above, in the control valve 1 of the present embodiment, the single outlet chamber 24 is provided immediately downstream of the valve port 22, and the communication hole 26 that communicates the outlet chamber 24 with the outside of the valve is provided. The refrigerant is led from the valve port 22 to the single lead-out chamber 24 and is led from the lead-out chamber 24 through the four communication holes 26 to the crank chamber of the compressor, as shown in FIG. When the refrigerant exits the valve port 22, it is not diverted and flows evenly along the entire inner peripheral edge of the valve port 22. Therefore, local wear and erosion of the inner peripheral edge portion of the valve port 22 can be effectively suppressed, and valve leakage, valve rod malfunction, and the like are less likely to occur.

  The communication hole 26 is provided on the opposite side of the guide hole 19 formed in the convex stopper portion 28 with the lead-out chamber 24 interposed therebetween, and the refrigerant passes through the lead-out chamber 24 and the communication hole 26 from the valve port 22. Since the flow is made so as to draw a reverse U shape when viewed from the side, it is difficult for foreign matter to enter the sliding surface gap α between the guide hole 19 and the upper fitting insertion portion 15d of the valve stem 15, and the valve stem 15 is locked. It is possible to make it difficult for malfunctions to occur.

  Moreover, the effect that the pressure loss does not change can be obtained depending on the mounting angle of the control valve with respect to the compressor. That is, as shown in FIG. 2, the communication hole 26 is formed so as to be orthogonal to (not opposed to) the refrigerant passage P of the compressor-side mounting hole H, and therefore the mounting angle (center) of the control valve 1 with respect to the mounting hole H The pressure loss hardly changes according to the angle around the axis. Therefore, it is not necessary to consider the mounting angle of the control valve 1 with respect to the compressor, and the mounting property is improved.

DESCRIPTION OF SYMBOLS 1 Control valve 15 for variable capacity type compressors Valve rod 15A Lower rod-shaped member 15B Upper convex member 19 Guide hole 20 Valve body 21 Valve chamber 22 Valve port 24 Deriving chamber (refrigerant outlet)
26 Communication hole (refrigerant outlet)
28 Convex stopper (partition)
30 Electromagnetic actuator 40 Bellows device

Claims (4)

A valve stem having a valve body portion, a guide hole into which the valve rod is slidably inserted, and a valve chamber provided with a valve port for contacting and separating the valve body portion, upstream of the valve port A discharge pressure refrigerant introduction port for introducing a discharge pressure refrigerant from the compressor, and a valve main body provided with a refrigerant outlet port communicating with the crank chamber of the compressor downstream from the valve port; An electromagnetic actuator having a plunger for moving the valve stem in the valve closing direction, a pressure sensing chamber into which suction pressure is introduced from the compressor, and opening the valve stem according to the pressure in the pressure sensing chamber A control valve for a variable displacement compressor having a pressure-sensitive responsive member that presses in a direction,
The refrigerant outlet port has a single outlet chamber provided immediately downstream of the valve port, and a communication hole that communicates the outlet chamber with the outside of the valve so that the refrigerant is not divided when leaving the valve port. A control valve for a variable displacement compressor, comprising:   The control valve for a variable displacement compressor according to claim 1, wherein a plurality of the communication holes are provided.   A partition wall portion having the guide hole is formed above the valve port in the valve body, the lead-out chamber is provided between the partition wall portion and the valve port, and the communication hole sandwiches the lead-out chamber. The control valve for a variable displacement compressor according to claim 1 or 2, wherein the control valve is provided on a side opposite to the guide hole.   4. The variable capacity compressor according to claim 1, wherein the refrigerant is flowed from the valve port through the outlet chamber and the communication hole so as to draw a reverse U shape in a side view. 5. Control valve.

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