Control valve assembly

• US 4,719,943 A
• Filed: 11/25/1986
• Issued: 01/19/1988
• Est. Priority Date: 08/16/1983
• Status: Expired due to Term

• Current Assignee: Parker Intangibles LLC (Parker-Hannifin Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Perach, Asi
• Primary Examiner(s): Nilson, Robert G.
• Application Number:
  US06/934,758
• Time in Patent Office: 420 Days
• Field of Search: 137/625.65, 251/129.05, 251/129.17
• US Class Current: 137/625.65
• CPC Class Codes: F16K 31/0606 fluid passing through the solenoid coil
• CPC Class Codes: F16K 31/0627 with movable valve member positioned between seats
• CPC Class Codes: Y10T 137/86622 Motor-operated

Abstract

A control valve assembly 10 having a pair of axially opposed seats 54, 56 is disclosed. A poppet 66 is disposed in a control chamber 58 between the seats. The poppet is movable between the seats to establish an average pressure in the control chamber. The poppet is a portion of an armature 28. In one embodiment, the armature is urged in a first direction by a solenoid and in the opposite direction by a spring 76 which extends between the armature and a housing of the valve. In another embodiment, means 310, such as diaphragms 312 or 314 or the slidable engagement 318, 320 between the housing 224 and the first end 251 of the armature are provided for radially positioning the armature as the armature is moved between the seats. In still another embodiment, the armature 228 is formed of a first section 416 and a second section 418 which are jointed by a shaft 434 which is slidable with respect to the first section.

Claims

1. A control valve assembly of the type adapted to be operated at a high frequency with a variable duty cycle, the valve having an axis Am, which comprises:

a housing having a cavity which extends axially within the housing, the housing further having

a first seat disposed in the cavity,

a second seat disposed in the cavity and spaced axially from the first seat leaving a control chamber therebetween,

a first port which adapts the valve assembly to be in fluid communication with a fluid at a first pressure, and which is in fluid communication through the first seat with the control chamber,

a second port which adapts the valve assembly to be in fluid communication with a region having a fluid at a second pressure which is not equal to the first pressure, and which is in fluid communication through the second seat with the control chamber,

a third port which is in fluid communication with the control chamber;

an armature having a first end and a second end, the armature extending axially about the axis Am, and being movable in a first direction to a first position and movable in a second direction to a second position, the armature having

a first section extending from the first end which is adapted to engage a shaft, the first section including

a poppet disposed in the control chamber which is adapted to engage the first seat at the first position of the armature and to engage the second seat at the second position of the armature, and

means integrally joined to the poppet for adapting the first section to engage a diaphragm,

a second section extending from the second end, the second section including

a plunger disposed in the cavity which is spaced axially from the poppet and which is spaced radially from the housing leaving a clearance gap Gr therebetween, and having an end spaced axially from the housing leaving an axial gap Ga therebetween,

a shaft which is integrally joined to the plunger and which extends axially from the plunger to the first section through one of said seats to axially engage the first section to join the poppet to the plunger and which is slidable with respect to the second section;

means engaging the first section for urging the poppet in one of said directions to engage one of said seats;

a coil extending circumferentially about at least a portion of the plunger for urging the poppet in the other of said directions to engage the other of said seats; and

,

means for radially positioning the armature from the housing as the armature moves between the first seat and the second seat under operative conditions and for resisting movement of the armature in the radial direction which includes an annular diaphragm having an outer portion attached to the housing and having an inner portion which is engaged by the means for adapting the first section to engage a diaphragm to attach the inner portion of the diaphragm to the first section of the armature at a location between the poppet and said first end of the armature, the diaphragm extending circumferentially about the axis Am between the armature and the housing to bound a flow path for fluid extending through the contral chamber and to block the fluid from contacting said first end of the armature and the diaphragm extending axially to adapt the diaphragm to exert a centering force on the armature in response to the static pressure of the fluid as the poppet moves between the seats;

wherein forces exerted on the first section of the armature are transmitted to the poppet to positively drive the poppet at high frequencies from the first seat to the second seat and from the second seat to the first seat to establish an average pressure in the control chamber which is a function of the time spent at each seat and between the seats, and wherein the inertia of the first section of the armature and the means for radially positioning the armature act to resist movement of the poppet in the radial direction in response to fluid forces acting on the poppet as the poppet moves between the seats.

2. The control valve assembly of claim 1 wherein the first section is adapted to engage the shaft, the shaft engaging the first section such that the first section is pulled in the direction of the second section in response to movement of the plunger of the second section, and wherein the means engaging the first section for urging the poppet in one of said directions is a spring which is compressed as the first section is pulled by the plunger, the spring urging the first section against the shaft to cause the shaft to press against the first section.

3. The control valve assembly of claim 2 wherein the control valve assembly further includes another means for urging the shaft against the first section extends between the first section and the second section.

4. The control valve assembly of claim 2 wherein the means for urging the shaft against the first section includes a spring extending about the shaft which exerts a force against the first section and against the second section.

5. The control valve assembly of claim 4 wherein the first seat and the second seat are annular, flat surfaces which face each other, wherein the poppet is an annular disk-like element and wherein the means integrally joined to the poppet is an end plate having a mass which is greater than the mass of the poppet and which is spaced from the poppet to trap the inner portion of the diaphragm against the poppet.

6. The control valve assembly of claim 1 or 2 wherein the annular diaphragm has a curved section extending between the outer portion and the inner portion of the diaphragm and wherein the curved section of the annular diaphragm is radially aligned with the line of contact between the poppet and the first seat so that the static pressure of the fluid which is flowed along the first flow path acts on the diaphragm in one of said directions and on the poppet in the other of said directions and causes the axial force exerted by the static pressure of the fluid along the first flow path on the armature under operative conditions to be reduced as compared with constructions in which no diaphragm opposes the static pressure of the fluid acting on the poppet.

7. The control valve assembly of claim 1 wherein the fluid contains metallic particles and wherein the diaphragm blocks the fluid containing metallic particles from areas of the valve adjacent to the electromagnetic coil.

8. The control valve assembly of claim 6 wherein said diaphragm has an inner wall attached to said inner portion, an outer wall attached to said outer portion, a curved section extending between the inner wall and the outer wall, the curved section having a concave side which faces the poppet and wherein a part of the inner wall of each diaphragm is parallel to a part of the outer wall of the diaphragm for a distance equal to or greater than the distance which the poppet must travel between the seats.

9. The control valve assembly of claim 8 wherein the armature has a surface which engages the parallel part of the inner wall of the diaphragm and the housing has a surface which engages the parallel part of the outer wall of the diaphragm, wherein said surfaces are parallel to each other and are parallel to Am and are adapted to move parallel to each other as the armature oscillates between the seats under operative conditions causing the cross-sectional shape of the curved section of each diaphragm to approximate a half-circle.

10. A control valve assembly of the type adapted to be operated at a high frequency with a variable duty cycle, the valve having an axis Am, which comprises:

a housing having a cavity which extends axially within the housing, the housing further having

a first seat disposed in the cavity,

a second seat disposed in the cavity and spaced axially from the first seat leaving a control chamber therebetween,

a first flow path for fluid extending through the first seat to the control chamber,

a first port which adapts the valve assembly to be in fluid communication with a fluid at a first pressure, and which is in fluid communication along the first flow path with the control chamber,

a second flow path for fluid extending through the second seat to the control chamber,

a second port which adapts the valve assembly to be in fluid communication with a region having a fluid at a second pressure which is not equal to the first pressure, and which is in fluid communication along the second flow path with the control chamber,

a third port which is in fluid communication with the control chamber;

an armature extending axially about the axis Am which has a first end, a second end, and which is movable in a first direction to a first position and movable in a second direction to a second position, the armature having,

a first section extending from the first end, the first section including a frustoconical surface opening toward the first end which adapts the first section to engage a shaft, the first section further including,

a poppet disposed in the control chamber having sides which are adapted to engage the first seat at the first position of the armature and to engage the second seat at the second position of the armature,

a first end plate having a mass which is greater than the mass of the poppet, the first end plate being disposed on one side of the poppet and being integrally joined to the poppet,

a second end plate having a mass which is greater than the mass of the poppet, the second end plate being disposed on the other side of the poppet and being integrally joined to the poppet,

a second section extending from the second end, the second section including,

a plunger at the second end which is disposed in the cavity, which is spaced axially from the poppet, and which is spaced radially from the housing leaving a clearance gap Gr therebetween, and having an end spaced axially from the housing leaving an axial gap therebetween,

a shaft integral with the second section which extends axially from the second section through one of said seats to the second section to join the poppet to the second section, the shaft having a curved surface which engages the frustoconical surface of the first section, and

means for urging the shaft against the surface of the first section as the poppet moves in either direction;

a first means for urging the first section of the armature in one of said directions to cause the poppet to engage one of said seats;

a coil extending circumferentially about at least a portion of the plunger for urging the first section in the other of said directions to cause the poppet to engage the other of said seats; and

,

means for radially positioning the first section of the armature as the armature moves between the seats under operative conditions which includes

a first annular diaphragm having an outer portion which is attached to the housing, having an inner portion which is attached to the first section of the armature at a location between the poppet and the first end of the armature, the diaphragm extending circumferentially about the axis Am between the armature and the housing to bound the first flow path for fluid and to block the fluid from contacting the first end of the armature;

a second annular diaphragm having an outer portion which is attached to the housing, having an inner portion which is attached to the first section of the armature at a location between the poppet and the second end of the armature, the diaphragm extending circumferentially about the axis Am between the armature and the housing to bound the second flow path for fluid and to block the fluid from contacting the plunger on the second end of the armature;

wherein forces exerted directly on the first section of the armature are transmitted to the poppet to positively move the poppet at high frequencies from the first seat to the second seat and from the second seat to the first seat to establish an average pressure in the control chamber which is a function of the time spent at each seat and between the seats, wherein isolation of the ends of the armature from the fluid reduces fluidic drag forces acting on the ends of the armature, and wherein the circumferentially extending diaphragms, the armature and the inertia of the plunger and the first section of the armature act to resist movement of the poppet in the radial direction in response to fluid forces acting on the poppet as the poppet moves between the seats.

11. The control valve assembly of claim 10 wherein the first diaphragm is trapped between the poppet and the first end plate and the second diaphragm is trapped between the poppet and the second end plate.

12. The control valve assembly of claim 10 or 11 wherein each of said diaphragms has an inner wall attached to said inner portion, an outer wall attached to said outer portion, a curved section extending between the walls, the curved section having a concave side which faces the poppet and wherein a part of the inner wall of each diaphragm is parallel to a part of the outer wall of the diaphragm for a distance equal to or greater then the distance which the poppet must travel between the seats.

13. The control valve assembly of claim 12 wherein the curved section of at least one of said annular diaphragms is radially aligned with the line of contact between the poppet and the first seat so that the static pressure of the fluid which is flowed along the first flow path acts on the diaphragm in the first direction and on the poppet in the second direction and causes the axial force exerted on the armature by the static pressure of the fluid flowed along the first flow path to be reduced as compared with constructions in which no diaphragm opposes the static pressure of the fluid acting on the armature.

14. The control valve assembly of claim 12 wherein the armature has a surface which engages the parallel part of the inner wall of the diaphragm and the housing has a surface which engages the parallel part of the outer wall of the diaphragm wherein said surfaces are parallel to each other and are parallel to Am and are adapted to move parallel to each other as the armature is oscillated between seats under operative conditions causing the cross-sectional shape of the curved portion of each diaphragm to approximate a half-circle to reduce shearing stresses in the diaphragm under operative conditions.