Abstract:
There is provided a fluid rerouting system for valve bodies that use hydraulic pressure, via a balance pressure line, to move spools. In an exemplary embodiment, the system comprises a valve sleeve having a plurality of ports that are substantially aligned with a plurality of fluid connections in the mating bore, except that no valve sleeve port aligns with the balance pressure line. The system also includes a spool having a plurality of lands that are sized and configured to fit slidably in said valve sleeve. The combination of the valve sleeve and at least one of the lands form a chamber, fluid access to which is via an aperture traversing the land. Means for blocking the access of said balance pressure line to said valve sleeve are also included.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to the field of valve assemblies. In particular, the present invention is directed to a valve body fluid rerouting system. 
       BACKGROUND 
       [0002]    Transmissions and other types of valve bodies typically contain several valve assemblies that move in response to hydraulic pressure. In an automobile transmission, for example, numerous valve assemblies may be in fluid communication with one another, with each valve assembly independently oscillating in response to hydraulic pressure changes occurring in the transmission. While there are many different types of valve assemblies, a typical valve assembly includes a spool, a spring, a plug, and a retaining pin. These valve assemblies reside inside a mating bore, a hole in the valve body that is sized for the corresponding valve assembly. 
         [0003]      FIGS. 1A and 1B  are schematic diagrams of typical prior art hydraulic circuits. Valve body  100  contains a fluid circuit that includes a valve assembly  104 , which includes a spool  108 , a spring  112 , and a plug  116 . Valve assembly  104  communicates with other components in the fluid circuit, such as fluid strainer  120  and receiving valve assembly  124 , via a first fluid line  128  and a second fluid line  132 . 
         [0004]      FIG. 1A  shows valve assembly  104  in the substantially open position inside mating bore  102 . While in the open position, first fluid line  128  delivers fluid to a chamber  136 , which then exits to second fluid line  132 . Fluid leaving chamber  136  flows to either receiving valve assembly  120  or to a balance pressure line  140 . As shown in  FIG. 1A , balance pressure line  140  is at least partially blocked by spool  108 . In operation, as hydraulic pressure builds in second fluid line  132  (a result of diminished fluid exiting the receiving valve assembly  124  and continuing accumulation of fluid from first fluid line  128 ), fluid enters behind spool  108  via balance pressure line  140 . As fluid accumulates behind spool  108 , spool  108  moves against spring  112  to the substantially closed position shown in  FIG. 1B . 
         [0005]    While in the substantially closed position, the hydraulic pressure in second fluid line  132  decreases as fluid exits receiving valve assembly  124 . As the hydraulic pressure decreases, spring  112  moves spool  108  into the substantially open position, thus restoring access to chamber  136  by first fluid line  128 . 
         [0006]    As the valve moves back and forth in response to changes in hydraulic pressure, the spool lands brush against the mating bore. The repeated oscillations wear down the spool lands, the mating bore, or both. The wear allows fluid that would otherwise be contained in a valve chambers to spread into the worn area between the spool land and the mating bore. In cases where the wear is sufficient, the fluid may move from one valve chamber to another, effectively reducing the ability of the valve to effectively control fluid communications, thus disrupting fluid control in the valve body. 
         [0007]    Repairing a worn mating bore and valve assembly is both time consuming and costly. Typically, the mating bore must be reamed to a larger size and a new, larger valve assembly is inserted. While this operation will correct the problem, the tooling required to ream the mating bore is expensive and the repair is labor intensive. 
       SUMMARY OF THE DISCLOSURE 
       [0008]    The present disclosure describes a system, apparatus and method for rerouting fluid communications in a valve body. In an exemplary embodiment of the present invention, a valve body fluid rerouting system is described that limits access to a mating bore by a balance pressure line and provides a means by which a spool will oscillate in response to hydraulic pressure in the valve body without the use of the balance pressure line via the existing balance pressure line port. 
         [0009]    In a preferred embodiment, a valve sleeve, having a plurality of ports, is sized and configured to fit slidably inside a mating bore. The ports of the valve sleeve correspond to fluid communication ports inside the mating bore, except that the valve sleeve does not have a port that corresponds to a balance pressure line. A spool, having a plurality of lands, is sized and configured to fit slidably inside the valve sleeve. The lands, in combination with the valve sleeve, create at least one chamber in the location where the balance pressure line would previously input fluids. Fluid access to this chamber is by an aperture in the spool, which thereby provides the hydraulic pressure for opening and closing of the valve. A balance pressure orifice is also blocked in order to prevent fluid from entering between the valve sleeve and the mating bore. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein: 
           [0011]      FIG. 1A  is a schematic diagram of a prior art fluid circuit for a valve body containing a valve assembly in the substantially open position; 
           [0012]      FIG. 1B  is a schematic diagram of a prior art fluid circuit for a valve body containing a valve assembly in the substantially closed position; 
           [0013]      FIG. 2  is a perspective, exploded view of an exemplary fluid rerouting valve assembly outside of a mating bore according to an embodiment of the present invention; 
           [0014]      FIG. 3A  is a schematic fluid circuit diagram of a valve body containing an exemplary valve body fluid rerouting system in the substantially open position according to an embodiment of the present invention; 
           [0015]      FIG. 3B  is a schematic fluid circuit diagram of a valve body containing an exemplary valve body fluid rerouting system in the substantially closed position according to an embodiment of the present invention; and 
           [0016]      FIG. 4  is a perspective view of a valve body with a separator plate and a separator plate plug according to an embodiment of the present invention; 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Referring now to the drawings,  FIG. 2  illustrates an example of a valve body fluid rerouting system  200  in accordance with an exemplary embodiment of the present invention. Generally, valve body fluid rerouting system  200  is suitable for replacing a pre-existing valve assembly in an existing valve body  100  when mating bore  102  or valve spool  108  has worn. As will be discussed more fully below, valve body fluid rerouting system  200  reroutes fluid communication paths in valve body  100  so that the valve assembly can be replaced and properly function without the need for reaming or other special machining of valve body  100 . 
         [0018]    Valve body fluid rerouting system  200  is suited for, but not limited to, being a replacement for a solenoid modulator valve in an automobile transmission. Exemplary transmissions include Aisin Warner and Nissan transmissions AW55-50SN, AW55-51SM, AF 23/33, or RE5F22A, but persons of ordinary skill in the art will readily identify other suitable applications based on the teachings of the present disclosure. 
         [0019]    As valve body fluid rerouting system  200  is intended to be a direct replacement for an existing valve assembly with a worn spool  108  or in a worn bore  102 , embodiments of the present invention are described herein in connection with the prior art valve body  100  and its fluid circuit as shown in  FIGS. 1A and 1B . Details of an exemplary embodiment of the present invention are shown in  FIGS. 2-4 . 
         [0020]    Referring first to  FIG. 2 , a valve body fluid rerouting system  200  according to an exemplary embodiment includes a valve sleeve  212 , a spool  216 , a biasing member  220 , a bore plug  224 , a retaining pin  228 , and a separator plate plug  232  (shown on  FIG. 4 ). Valve sleeve  212  is generally sized and configured to fit slidably into mating bore  102  and has a plurality of ports  236  corresponding to communication ports inside valve body  100 , such as fluid input, fluid outlet, and exhaust ports. In an exemplary embodiment, valve sleeve  212  has four ports, i.e.,  236 A-D, that correspond to a first fluid line  128 , a second fluid line  132 , and exhaust points. 
         [0021]    Spool  216  may have a plurality of coaxial lands. In an exemplary embodiment, spool  216  has a first land  240  and a second land  244  that are sized and configured to fit slidably in valve sleeve  212 . Spool  216  may also have an aperture  248  extends diagonally (top to bottom) through first land  240  (best seen in  FIG. 3 ). 
         [0022]    Biasing member  220  is generally chosen to resist axial movement of spool  216  toward bore plug  224 . In an exemplary embodiment, biasing member  220  is a compression spring sized and configured to fit into valve sleeve  212  and around a distal post  252  of spool  216 . Bore plug  224  is generally sized and configured to fit slidably in mating bore  102  after valve sleeve  212 , spool  216  and biasing member  220  are placed into mating bore  102 . Bore plug  224  is generally held in place via retaining pin  228 . In an alternative embodiment, bore plug  224  may be sized and dimensioned to slide into valve sleeve  212  so long as a secure hydraulic seal is maintained inside valve sleeve  212 . 
         [0023]    Valve body fluid rerouting system  200  may additionally include separator plate plug  232 . In an exemplary embodiment, separator plate plug substantially blocks balance pressure line  140  (best seen in  FIG. 3A ) access to valve sleeve  212 . In a preferred embodiment, separator plate plug  232  is inserted into balance pressure orifice  272  (as shown on  FIG. 4 ) in separator plate  260  and the separator plate plug is peened over on both sides. 
         [0024]    The present disclosure is best understood by describing the movement of a fluid in valve body  100  using valve body fluid rerouting system  200 .  FIG. 3A-B  illustrates an exemplary fluid circuit containing valve body fluid rerouting system  200  and other components of a typical valve body that may include, but are not limited to, a fluid strainer  120  and a receiving valve assembly  124  as previously described. 
         [0025]    In an exemplary embodiment and as shown in  FIG. 3A , when spool  216  is in the substantially open position, first fluid line  128  may deliver fluid to a first chamber  320 , which is formed between first land  240  and second land  244  and enclosed by valve sleeve  212 . Fluid in first chamber  320  exits to second fluid line  132  and may thereafter be routed to either receiving valve assembly  124  or to balance pressure line  140 . Notably, in valve body fluid rerouting system  200  balance pressure line  140  is substantially blocked. Thus, fluid is prevented from accessing the rear of spool  216  via balance pressure line  140 . 
         [0026]    As the hydraulic pressure in second fluid line  132  increases, fluid may fill a second chamber  328  located behind spool  216  through aperture  248 , the second chamber being formed by the intersection of the top of first land  240  and valve sleeve  212 . As fluid fills second chamber  328 , fluid pressure may react against the top of first land  240 , thus expanding second chamber  328  and moving spool  216  against biasing member  220 . 
         [0027]    When sufficient hydraulic pressure has accumulated in second fluid line  132 , spool  216  generally moves to a substantially closed position as shown in  FIG. 3B . In a substantially closed position, first land  240  substantially blocks first fluid line  128 . As hydraulic pressure in second fluid line  132  decreases, e.g., fluid moves through receiving valve assembly  124 , fluid travels from second chamber  328  to first chamber  320  through aperture  248 . As fluid moves out of second chamber  328 , biasing member  220  moves spool  216  to a substantially open position, thus restoring fluid communication between first fluid line  128  and second fluid line  132 . 
         [0028]    Valve sleeve  212  and spool  216  may be constructed of a variety of metals known in the art. Exemplary metals include, but are not limited to, carbon steels, alloy steels, stainless steels, aluminum, and aluminum alloys, among others. Materials may be selected based on one or more desirable physical properties, e.g., strength, hardness, durability, malleability, machinability, coefficient of thermal expansion, and/or drilling characteristics. The materials will typically be selected to cooperate with each other. In one embodiment, valve sleeve  212  is made of steel, which would typically, but not necessarily, result in carburized steel material chosen for spool  216 . In another embodiment, valve sleeve  212  is made of 4032 aluminum, which would typically, but not necessarily, result in hard-coat anodized aluminum material chosen for spool  216 . In an exemplary embodiment, valve sleeve  212  is constructed of hardened carbon steel that has a Rockwell Superficial Hardness 15N-Scale (HR 15N) range of 74-77 (Rockwell Hardness C-Scale (HRC) range of 28-34) while spool  212  is made of low carbon steel that has been carburized such that it has a HR 15N range of 89-92 (HRC 58-62). In an alternative embodiment, valve sleeve  212  is constructed of hardened carbon steel that has HR 15N range of 70-77 (HRC range of 20-34). 
         [0029]    Valve sleeve  212  may have different constructions including, for example, a continuous body or an assembly of separate members that are sized and configured to conform to mating bore  102  and to receive spool  216 . A construction consistent with a continuous body, for instance, may consist of valve sleeve  212  having a continuous cylindrical body and providing ports  236 . A construction consistent with an assembly of separate members, for instance, may include two or more cylindrical sections that combine to make a valve sleeve  212  and provide ports  236 . While valve sleeve  212  as described in an exemplary embodiment is generally cylindric, it is understood that valve sleeve  212  can take on any number of shapes known in the art. Valve sleeve  212  may be made in the image of a member of the prisamatoid family, including parallelograms, cuboids, etc. As a person skilled in the art will readily identify, the shape and size of valve sleeve  212  will generally correspond to the size and shape of mating bore  102  such that valve sleeve  212  will fit slidably into mating bore  102  and, in addition, so that valve spool  216  will fit slidably into valve sleeve  212 . 
         [0030]    Spool  216  will generally take on a shape that corresponds to fit slidably in valve sleeve  212 . In an exemplary embodiment, spool  216  is generally cylindric, but as a person skilled in the art will readily identify spool  216  can take on any number of shapes known in the art. Spool may have a distal knob  268  (best seen in  FIG. 3B ) on first land  240  to prevent hydraulic locking. One skilled in the art would understand that other arrangements may prevent hydraulic locking of spool  216  in valve sleeve  212  including, but not limited to, a flange coupled to the top of first land  240  or a flange coupled to the inside of valve sleeve  212 . 
         [0031]    First land  240  and second land  244  may be coupled via connector  264 . In one example, connector  264  is generally cylindrical body that is coaxial to first land  240  and second land  244 . As a person skilled in the art will readily identify, connector  264 , in addition to coupling together multiple lands, may also serve to create the space necessary for first chamber  320 . Thus, a person skilled in the art will easily recognize that connecter  264  may take on many shapes known in the art that would suffice to connect first land  240  to second land  244  such as cylinders, cuboids, parallelepipeds, or other members of the prisamatoid family, e.g., multi-sided parallelograms, pyramids, and frusta, which couple multiple lands and provide space for first chamber  320 . 
         [0032]    Aperture  248  may extend from the top surface of first land  240  to connector  264 . In an exemplary embodiment, aperture  248  is generally cylindric, forming an angle of approximately twenty degrees with the axial position of spool  216 . In this embodiment, aperture  248  begins at the top of first land  240 , which is located proximate distal knob  268 , and continues an exit in the side wall of connector  264 . In an alternative embodiment, aperture  248  may run colinear to the axis of spool  216 , i.e., from the top surface of first land  240  to the bottom surface of the first land, if connector  264  is of sufficiently small size to allow adequate exit on the bottom surface of the first land. 
         [0033]    Second land  244  may have a retaining element such as distal post  252  coupled to its bottom surface. In one example, distal post  252  is generally of such length so as to not come into contact with a bore plug  224  when spool  216  is in a substantially closed position (not shown) and to support biasing member  220 . In an exemplary embodiment, distal post  252  has an altitude that is at least fifty-five percent of length of biasing member  220 . 
         [0034]    Biasing member  220  may have an ability to resist axial movement of spool  216  until the pressure in second fluid line  132  of valve body  100  reaches a certain amount. In an exemplary embodiment, biasing member  220  is a compression spring that has an outside diameter of approximately 0.250 inches, an uncompressed length of approximately 1.073 inches, and a spring constant of approximately 15.88 lbs./in. Although in a preferred embodiment biasing member  220  is a compression spring, other means are known in the art may be used to oppose the axial movement of spool  216 , such as hydraulic or electric resistance devices. 
         [0035]    Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the spirit and scope of the present invention.