Patent Application
20070151614
The present invention generally relates to valves and, in particular, to spool valves.
Automotive transmissions and power steering systems require adequate hydraulic pressure for reliable operation and currently, solenoid valves are the most common way for regulating hydraulic pressure. The solenoid typically includes a solenoid coil with an armature attached to a pressure balanced spool for controlling fluid flow to outlet ports in a bore in which the spool is closely fitted. In such valves, the solenoid current is increased to electromagnetically move the armature and spool to progressively close the flow from the inlet to the outlet ports in the bore.
As the fluid flows from the inlet port into the bore, any contaminants that may be present in the fluid are transferred into the solenoid valve. The contaminants may interfere with the movement of the pressure balanced spool, and thus, cause a disruption or disturbance in the regulation of the fluid flow.
The present invention recognizes some of these and other considerations that may be associated with pressure relief valves. In an embodiment, the invention includes a valve assembly comprising valve portion including a bore and a longitudinal axis, a spool received within the bore and configured for axial movement about the longitudinal axis between an open position in which fluid flow through the bore is permitted, and a closed position in which fluid flow through the bore is prevented, a solenoid including an armature configured for axial movement along the longitudinal axis; and a shaft operatively engaging the armature to the spool. The shaft is capable of moving the spool axially along the longitudinal axis and an impellor secured to the spool is configured to rotate the spool about the longitudinal axis.
Referring now to the
Pressure regulating valve 10 may be controlled by an electronic control unit (“ECU”) (not shown) mounted in a vehicle (not shown). Pressure regulating valve 10 meters fluid flow to achieve a predetermined fluid pressure within a system of a vehicle. One exemplary embodiment of the invention has been applied to regulating the flow of oil provided to a clutch (not shown) within a transmission (not shown) of the vehicle.
It can be appreciated that solenoid 12 is generally known and comprises a housing 16 surrounding an electrical insulator 18. Within insulator 18 is a bobbin 20 bound by electrically conductive wire 22. Bobbin 20 and electrically conductive wire 22 surround a pole 24 and a flux 26. A cylindrical armature 28 made from magnetically responsive material is provided within a cavity 30b formed between pole 24 and flux 26. A second cavity 30a is formed within pole 24 and includes a spring plate 29. Spring plate 29 is capable of being coupled on one end to a spring 32 and on an opposing end to a shaft 34. Spring 32 may be located within a screw adjust 33. Shaft 34 extends along a longitudinal axis A-A and passes through an aperture 36 in flux 26 to abut hydraulic valve 14 and an aperture 37 in pole 24 to abut armature 28.
An alignment member 40 may be provided between shaft 34 and pole 24 and a second alignment member 38 may be provided between shaft 34 and flux 26. Alignment members 38, 40 may be press fit into apertures 36, 37 and may serve to stabilize shaft 34 along longitudinal axis A-A.
In the illustrated embodiment, housing 16 may be fabricated from any electrically conductive material, including, for example copper and bobbin 20 may be manufactured from any material, including for example, a plastic. Insulator 18 may be fabricated from any electrically non-conductive material. Pole 24 and flux 26 may be fabricated from any metal, such as a corrosion resistant steel, electrically conductive wire 22 may be manufactured from any conductive metal, such as copper. Electrically conductive wire 22 should be electrically insulated such that adjoining windings do not form an electrical path. Alignment members 38,40 may be manufactured from any number of materials, including for example, stainless steel. It can be appreciated that materials used in the manufacture of solenoid 12 may be selected for compatibility with the varying types of applications in which pressure regulating valve 10 may be utilized, including the particular mechanical, thermal and chemical conditions of the application, and may be selected, for instance, to optimize functional reliability, fluid compatibility, service life and cost.
Solenoid 12 may be energized, to generate an electromagnetic force that acts upon armature 28 urging it against the force of spring 32. If sufficient force is imparted to armature 28 by solenoid 12, armature 12 will move to compress spring 32 (i.e. armature 12 will move leftward). Thereafter, armature 28 may cause shaft 34 and hydraulic valve 14 to also displace, or slide, in an axial direction along axis A-A. The sliding of armature 28, shaft 34 and hydraulic valve 14 along axis A-A may cause the flow of fluid within hydraulic valve 14 to change. The electromagnetic force that acts on armature 28 may be adjusted by controlling an amount of a current passed through solenoid 12 by the ECU. Therefore, the flow of fluid may be regulated by the electromagnetic force and the resulting axial movement of the armature 28, shaft 34 and hydraulic valve 14.
Hydraulic valve 14 includes a valve body 42 having a bore 44. As illustrated, bore 44 may be fabricated such that it transitions between a first, or larger diameter 51 to a second, or smaller diameter 53. A spool 46 is received within the bore 44. Spool 46 may be configured for axial movement along axis A-A, between an open position, as shown in
In an embodiment, spool 46 is generally cylindrical and may include two opposing ends 48, 49 that are adapted to engage an inner surface 52 of bore 44, with a connecting shaft 54 therebetween. Valve seats 56, 58 are formed where opposing ends 48, 49 join connecting shaft 54, respectively. As illustrated in the
Referring now to
Impellor 60 may be integrally formed from connecting shaft 54 or it may be formed as a separate element which is then secured to connecting shaft 54. In an embodiment, connecting shaft 54 may transition from a first diameter 70 to a second diameter 72 and include a lip 73 where first diameter 70 transitions into second diameter 72. Impellor 60 may be secured to connecting shaft 54 such that base 66 of impellor 60 abuts lip 73 of connecting shaft 54 and end 68 of impellor 60 abuts opposing end 49 of spool 46. Alternatively, impellor may be secured to connecting shaft 54 such that end 68 of impellor 60 abuts lip 73 and base 66 of impellor 60 abuts opposing end 49 of spool 46. In either case, impellor 60 is prevented from sliding along connecting shaft 54 by lip 73.
As illustrated in
It can be appreciated that impellor 60 may be secured to spool 46 by any number of methods, including by welding, a friction fit, adhesives, or the like. In another embodiment, as illustrated in
Referring to
Hydraulic valve 14 may further include a bleed orifice 88 upstream of spool 46. In an embodiment, bleed orifice 88 is secured to valve body 42 by means of threading bleed orifice 88 to valve body 42. However, it can be appreciated that the invention is not limited by how bleed orifice 88 is secured to valve body 42. Bleed orifice includes an aperture 90 that allows access fluid to bleed, or discharge, out of bore 44 when hydraulic valve 14 moves from a closed to an open position, and vice versa. Hydraulic valve 14 may also include a reservoir cap 92 that encloses bleed orifice 88. Similar to bleed orifice 88, reservoir cap 92 may include a bleed hole 94 for allowing excess fluid to escape from hydraulic valve 14.
As fluid enters bore 44 through inlet port 82, the fluid exerts a force F on individual blades 64 of impellor 60. Force F may be divided into a radial component F
During normal operation of pressure regulating valve 10, hydraulic valve 14 is in the open position and is moved to the closed position when solenoid 12 energizes. If desired, pressure regulating valve 10 can be configured for use as a standard in-line device that regulates pressure conditions at inlet port and closes virtually instantaneously to prevent an over-pressure condition and any impulse pressure spikes from entering control port or exiting exhaust port. When so configured, hydraulic valve 14 may include a threaded male connector (not shown) on its downstream end and a threaded female connector (not shown) on its upstream end, or any combination of industry standard connectors. Alternatively, pressure regulating valve 10 may be configured as a coupling or an adapter configured to mate with a threaded or quick-connect/disconnect style fitting. Furthermore, pressure regulating valve 10 is not limited to a specific size and can cover a wide range of both conventional and unconventional sizes.
Having described various embodiments of the invention, it will be understood that various modifications or additions may be made to the embodiments chosen here to illustrate the present invention, without departing from the spirit of the present invention. For example, both “hydraulic” and “fluid” have been used to describe the valve disclosed herein. Although the present invention can be used in hydraulic applications, there is nothing that prevents the valve disclosed herein from also being used in pneumatic applications (such as compressed gas) or those applications relating to pressurized steam. Accordingly, it is to be understood that the subject matter sought to be afforded protection hereby shall be deemed to extend to the subject mater defined in the appended claims (including all fair equivalents thereof).
