Patent Application
20120325331
The present invention generally relates to the field of pressure regulation in automotive transmissions. In particular, the present invention is directed to a pressure regulator valve replacement assembly.
The transmission fluid used in automotive transmission systems is often pressurized using a positive displacement pump. That is, the pump delivers the same volume of transmission fluid to the fluid circuits within the transmission at every pump-cycle regardless of the volume of transmission fluid already within the fluid circuits. This may lead to over-pressurizing the transmission fluid such that it may damage valves or other components in fluid communication with the transmission fluid. Given this risk, the valves and components in fluid communication with the fluid circuit require protection from damaging fluid pressures.
The valves and components of the transmission may be protected using a pressure regulator valve. A typical pressure regulator valve diverts some of the automatic transmission fluid from the input fluid circuit to the transmission fluid pump reservoir, thereby bypassing the fluid circuits and reducing the pressure of the transmission fluid. However, some designs of pressure regulator valves may deprive critical components of needed transmission fluid at low values of torque transmitted by the torque converter or at low pressures of the transmission fluid. This deprivation may cause overheating of the transmission fluid, among other detrimental effects. Additionally, the deprivation of transmission fluid may also cause the engine to stall by preventing a lock-up clutch from disengaging at low torque converter torque values.
In one implementation, the present disclosure is directed to a pressure regulator valve assembly for maintaining a flow of automatic transmission fluid from an input fluid circuit to a torque converter fluid circuit and a transmission cooling fluid circuit of Honda Transmissions during low torque operation of a torque converter, the Honda Transmissions including a bore in fluid communication with the input fluid circuit, the torque converter fluid circuit and the transmission cooling fluid circuit. The pressure regulator valve assembly comprises a valve piston subassembly receivable in the bore in the transmission, said valve piston subassembly including a piston body coupled to a valve stem, said piston body having two terminal control diameters and at least one intermediate control diameter disposed between said two terminal control diameters, said at least one intermediate control diameter having an exterior surface in fluid communication with the bore when positioned in the bore, said valve piston subassembly including a valve chamber positioned substantially within said intermediate control diameter and configured to extend to said exterior surface so as to be in fluid communication with (i) said exterior surface and (ii) the bore when said valve piston subassembly is positioned in the bore; and a check ball disposed within said valve chamber so as to be movable between (i) a first position where said check ball is located so that said valve chamber is in fluid communication with the bore and hence the input circuit, the torque converter circuit, and the cooling circuit when the valve piston subassembly is positioned in the bore so that the automatic transmission fluid may be channeled from the input circuit to the torque converter circuit via said valve chamber and (ii) a second position where said check ball is located to occlude said valve chamber such that said valve chamber is not in fluid communication with the input circuit, whereby automatic transmission fluid is not channeled from the input circuit to the torque converter circuit.
In another implementation, the present disclosure is directed to a Honda Transmission modified to maintain a flow of automatic transmission fluid from an input fluid circuit to a torque converter fluid circuit and a transmission cooling fluid circuit during low torque operation of a torque converter. The Honda Transmission modified to maintain a flow of automatic transmission fluid comprises a bore; a pressure regulator assembly including: (i) a valve piston subassembly received in the bore in the transmission, said valve piston subassembly including a piston body coupled to a valve stem, said piston body having two terminal control diameters and at least one intermediate control diameter disposed between said two terminal control diameters, said at least one intermediate control diameter having an exterior surface in fluid communication with said bore, said valve piston subassembly including a valve chamber positioned substantially within said intermediate control diameter and configured to extend to said exterior surface so as to be in fluid communication with (i) said exterior surface and (ii) said bore; and (ii) a check ball disposed within said valve chamber so as to be movable between (i) a first position where said check ball is located so that said valve chamber is in fluid communication with the bore and hence the input circuit, the torque converter circuit, and the cooling circuit when the valve piston subassembly is positioned in the bore so that the automatic transmission fluid may be channeled from the input circuit to the torque converter circuit via said valve chamber and (ii) a second position where said check ball is located to occlude said valve chamber such that said valve chamber is not in fluid communication with the input circuit, whereby automatic transmission fluid is not channeled from the input circuit to the torque converter circuit.
In yet another implementation, the present disclosure is directed to a method of maintaining a flow of transmission fluid from an input fluid circuit to a torque converter fluid circuit and a transmission cooling fluid circuit of a Honda Transmission during low torque operation of a torque converter of the Honda Transmission. The method of maintaining flow of transmission fluid comprises providing a valve piston subassembly receivable in a regulator valve bore in the Honda Transmission, the valve piston subassembly including a piston body having two terminal control diameters and at least one intermediate control diameter disposed between the two terminal control diameters, the at least one intermediate control diameter having an exterior surface, the valve piston subassembly including a valve chamber positioned substantially within the intermediate control diameter and configured to extend to the exterior surface so as to be in fluid communication with (i) the exterior surface and (ii) the bore when said valve piston subassembly is positioned in the bore, the valve chamber including a check ball biased by a spring; and channeling the transmission fluid from the input fluid circuit to the torque converter fluid circuit and the cooling fluid circuit during low torque operation of the torque converter through the valve chamber positioned substantially within the intermediate control diameter, the transmission fluid from the input fluid circuit being provided at sufficient pressure to overcome the bias force from the spring on the check ball.
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:
Embodiments of the present invention disclosed herein include a pressure regulator valve replacement assembly that may maintain a flow of transmission fluid to a torque converter fluid circuit and a transmission fluid cooler circuit during operating conditions of a torque converter in which low values of torque are produced. Because of the wide variety of designs of torque converters and the difficulty of generalizing a torque range that produces the configurations discussed herein, this disclosure will instead describe transmission fluid pressure regimes resulting from the action of a torque converter. Those skilled in the art will appreciate that the pressures described may correspond to a wide range of torque values depending on the particular torque converter design and operating conditions.
Among other advantages, supplying transmission fluid to the foregoing circuits at fluid pressures may facilitate disengaging a lock-up clutch connected to the torque converter. Certain examples disclosed herein are particularly well suited for use with the following Honda transmission models: M24A Model Years 1993 to 1997, A4RA Model Years 1996, B4RA Model Years 1997 to 2000, M4RA Model Years 1997 to 1998, BMXA Model Years 2001 to 2005, SLXA Model Year 2001, MDMA Model Years 1996 to 2000, MDLA Model Years 1998 to 2004, M4TA Model Years 1997 to 2004, SDMA Model Years 1997 to 1999, SP7A Model Years 1994 to 1999, S4XA Model Years 1994 to 1999, SKWA Model Years 2000 to 2001, B7TA Model Years 1999 to 2001, B7VA 1999 Model Year, B7ZA Model Years 1996 to 2000, M7ZA Model Years 1996 to 2000, B7XA Model Years 1998 to 2002, BAXA Model Years 1998 to 2002, B6VA Model Years 1998 to 1999, MAXA Model Years 1998 to 2002, MDWA 1998 Model Year, M6HA Model Years 1997 to 2001, BZKA Model Years 2003 to 2010, MZKA Model Years 2003 to 2010, MCVA Model Years 1998 to 2004, MRVA Model Years 1997 to 2004, BCLA Model Years 2003 to 2007, MCLA Model Years 2003 to 2007, MZHA Model Years 2007 to 2010, MZJA Model Years 2007 to 2010, BZHA Model Years 2008 to 2010, BZJA Model Years 2008 to 2010, B90A Model Years 2008 to 2011, M91A Model Years 2008 to 2011, MCTA Model Years 2004 to 2007, MKYA 2005 Model Year, MKZA Model Years 2005 to 2006, GPLA Model Years 2005 to 2007, GPPA Model Years 2005 to 2007, MM7A Model Years 2009 to 2011, MRMA Model Years 2002 to 2006, SMMA Model Years 2007 to 2008, SP5A Model Years 2009 to 2010, MP5A Model Years 2009 to 2010, SPCA Model Years 2006 to 2010, MPCA Model Years 2006 to 2010, K4 Model Years 1988 to 1991, PY8A Model Years 1990 to 1991, L4 Model Years 1983 to 1991, L5 Model Years 1986 to 1990, MPWA Model Years 1992 to 1994, P36A Model Years 2007 to 2011, B36A Model Years 2007 to 2011, B97A Model Years 2008 to 2011, BDHA Model Years 2007 to 2011, BDKA Model Years 2003 to 2007, MDKA Model Years 2003 to 2007, BJFA Model Years 2006 to 2008, MJFA Model Years 2006 to 2008, BWEA Model Years 2007 to 2011, MJBA Model Years 2005 to 2007, MURA Model Years 2005 to 2006, P34A Model Years 2009 to 2011, P35A Model Years 2009 to 2011, PN3A Model Years 2009 to 2011, PN4A Model Years 2009 to 2011, PSFA Model Years 2009 to 2011, BAYA Model Years 2003 to 2007, MAYA Model Years 2003 to 2007, BDGA Model Years 2004 to 2008, BGFA Model Years 2001 to 2006, MGFA Model Years 2001 to 2006, B7WA Model Years 2001 to 2005, MGHA Model Years 2001 to 2002, BGHA Model Years 2001 to 2002, BGRA Model Years 2005 to 2007, PGRA Model Years 2005 to 2007, BVGA Model Years 2003 to 2007, PVGA Model Years 2003 to 2007, BVLA Model Year 2007, PVLA Model Years 2003 to 2007, and BYBA Model Years 2002 to 2004. This group of transmissions, each transmission in the group, and other Honda transmissions suffering from the problems motivating the present invention, are referred to in the claims as the “Honda Transmissions.” While these transmissions are identified, those skilled in the art will appreciate that the teachings of the present disclosure are not limited to these transmissions, nor limited to automotive transmissions generally. Indeed, the broad teachings of the present disclosure may be applied to any number of systems in which a pressure regulator valve is used to regulate fluid pressure to fluid circuits at a variety of operating transmission fluid pressures.
Turning now to the figures,
Fluid communication between the aforementioned components may be through, for example, an input fluid circuit 132, a torque converter fluid circuit 136, and a transmission fluid cooler circuit 140. For example, transmission fluid is delivered from transmission fluid reservoir 130 to pressure regulator valve 108 through input fluid circuit 132. From input fluid circuit 132, transmission fluid may be delivered to torque converter 124, and lock-up clutch (not shown) through torque converter fluid circuit 136 and/or delivered to transmission fluid cooler 128 through fluid cooler circuit 140. Those skilled in the art will appreciate that these particular elements and fluid circuits are discussed here for the convenience of describing the examples of the present disclosure, and that the examples herein may be applied to other systems employing a pressure regulator valve and replacement assembly.
In transmission fluid circuit sub-system 100, fluid pump 104 may be a positive displacement pump that supplies a pre-determined amount of transmission fluid from transmission fluid reservoir 130 to input fluid circuit 132 at each cycle of the pump. As mentioned above, depending on the amount of transmission fluid already in sub-system 100, supplying a pre-determined amount of transmission fluid to the sub-system through input fluid circuit 132 may cause the fluid in the sub-system to become over-pressurized, thereby damaging the components of the sub-system. Those skilled in the art will appreciate that this type of damaging pressure may occur in a variety of fluid circuit configurations used in a variety of applications, and not merely those disclosed herein.
In order to reduce the risk of damaging over-pressure of the transmission fluid, input fluid circuit 132 is connected to pressure regulator valve 108, which may regulate the pressure of transmission fluid delivered to other fluid circuits. Pressure regulator valve 108 receives transmission fluid from input fluid circuit 132 through input ports 144a and 144b. As discussed below, pressure regulator valve 108 may divert excess transmission fluid to transmission fluid reservoir 130, thereby maintaining a non-damaging pressure of the transmission fluid within sub-system 100. Transmission fluid that is not diverted to reservoir 130 may then be channeled by pressure regulator valve 108 to torque converter fluid circuit 136 and fluid cooler circuit 140 through output port 148.
Piston body 216 has a valve chamber 248. Valve chamber 248 includes a check ball 252 that is disposed within the valve chamber. In fluid communication with valve chamber 248 is a bypass input duct 256, a bypass output duct 260 in fluid communication with the bypass input duct, and a check ball spring 264. Bypass input duct 256 is in fluid communication with exterior surface 265 of piston body 216 and bypass output duct 260 is also in fluid communication with the exterior surface. The interaction of these elements of valve replacement assembly 200 is discussed below in the context of three transmission fluid pressure regimes: operating pressure, low pressure, and no pressure.
In the example shown, a portion of the transmission fluid provided at a pressure exceeding a predetermined operating pressure is diverted by pressure regulator valve 108 from input fluid circuit 132 to fluid reservoir 130, thereby reducing the volume, and therefore the pressure, of transmission fluid delivered to the fluid circuits. In this way, pressure regulator valve 108 contributes to preventing damage to the components of sub-system 100.
In addition to preventing damage, one advantage of valve replacement assembly 200 when used in pressure regulator valve 108 is that it can maintain a flow of transmission fluid from input fluid circuit 132 to other fluid circuits, even at low transmission fluid pressures caused by low torque transmission of torque converter 124. In this example, low transmission fluid pressures are those that are insufficient to translate valve replacement assembly 200 within valve body 204. In the embodiment depicted in
One reason that maintaining transmission fluid flow to the components of sub-system 100 even at low pressures is advantageous is that it enables actuation of lock-up clutch control valve 112, lock-up shift valve 116, and lock-up clutch timing valve 120. Providing these components with fluid permits lock-up clutch 112 to be disengaged. In some examples of pressure regulator valves in the prior art, these components are deprived of transmission fluid at low pressures, preventing disengagement of the lock-up clutch from the torque converter causing the engine to stall at low torque values transmitted by the torque converter. Furthermore, valve replacement assembly 200 may maintain fluid communication between input fluid circuit 132 and transmission fluid cooler circuit 140 at low fluid pressures, thereby reducing the risk of sub-system 100 overheating when torque converter 124 is transmitting low torque.
In the example depicted in
In one embodiment of the above example, transmission fluid is delivered to piston body 216 through input ports 144a and 144b from input fluid circuit 132. Because ports 144a and 144b are approximately symmetric, the forces exerted on piston body 216 at these locations by the transmission fluid have approximately equal and opposing force-components that typically do not substantially translate the piston body in any single direction. In order to translate piston body 216 in a desired direction, an additional force may be applied to the piston body by channeling transmission fluid from input port 144a through duct 228 into balance port 212. The pressurized transmission fluid in balance port 212, exerting an asymmetric force on first terminal control diameter 224, may then translate valve replacement assembly 200 along longitudinal axis 218 toward stator arm plunger 244 (i.e., to the right in
Opposing the force exerted on first terminal control diameter 224 is a force provided by main pressure regulator springs 240a and 240b, as biased by stator arm plunger 244. In this example, main pressure regulator springs 240a and 240b act on second terminal control diameter 236 and valve stem 220. Those skilled in the art will appreciate that in some cases only one of main pressure regulator springs 240a and 240b may be needed to produce an adequate force. Analogous to the force provided at first terminal control diameter 224, the bias provided by stator arm plunger 244 is in proportion to the torque transmitted by torque converter 124. That is, the more torque that torque converter 124 transmits, the more bias stator arm plunger 244 provides to main pressure regulator springs 240a and 240b.
As mentioned above, both the force supplied by the pressurized transmission fluid and the force supplied by stator arm plunger 244 are proportional to the torque transmitted by torque converter 124. Therefore, because of this relationship, main pressure regulator springs 240a and 240b may be selected to have spring constants such that, over a range of force values, the forces are balanced so that control diameters 220, 232, and 236 are positioned with respect to ports 144a, 144b, 148, and 208 in order to channel transmission fluid into desired ports or, alternatively, to prevent fluid flow into select ports. In the example depicted in
Continuing with the present example, in
Specifically, referring to
Additionally, transmission fluid also flows from port 144a into output port 148 through gap 304a, bypass input duct 256, and bypass output duct 260. This particular path of fluid communication is maintained regardless of the axial position of valve replacement assembly 200 within valve body 204 and, rather, is a function of the position of a check ball 252 within valve chamber 248. The function of this aspect of valve replacement assembly 200 is discussed in more detail below for cases of low transmission fluid input pressure.
With reference to
The first potentially detrimental effect exhibited by some pressure regulator valves is sub-system 100 overheating caused by low transmission fluid pressures. As explained above and illustrated by
These two detrimental effects may be avoided by using valve replacement assembly 200 in valve body 204. For example, as shown in
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.
