FIELD OF THE INVENTION

The present invention relates to transmissions, and particularly to hydraulic control systems for transmissions.

BACKGROUND OF THE INVENTION

In the last six decades, the use of automatic transmissions has been very popular in automotive vehicles, initially, most automatic transmissions utilized fluid actuated valves to control the hydraulics of the transmission to actuate the various required clutches, synchronizers and related gear shifting apparatus. In a time period approximately in the 1980's, more and more automatic transmissions were converted to electronically controlled solenoid valves to control the gear shifting mechanisms of the automatic transmission to increase fuel economy. Accordingly, most automatic transmission utilized a plurality of solenoid actuated valves. For maintenance purposes, it is typically desirable to place most of these valves in a centra! hydraulic controller location. The valves will be fiuidly connected with their respective clutches and synchronizers via a valve body. The valve body provides a plurality of connective passages that connect each solenoid valve to the hydraulic function in the transmission that the valve is utilized for.

Current transmission hydraulic control solenoid valve applications utilize a solenoid valve with a cartridge sleeve and a valve body with a bore to provide a low cost solenoid interface into the valve body. The above noted application requires a precision cartridge valve sleeve diameter inserted within a precision valve body bore in order to reduce solenoid leakage. If the valve cartridge is off center with the valve body bore, increased leakage can be induced. A centered or port biased position provides the lowest leakage but is not easily achieved. Low solenoid leakage is desirable to reduce oil pump lost energy. Lost energy reduces power train efficiency thus impacting vehicle fuel economy. Accordingly, it is desirable to provide a new solenoid mounting system which reduces leakage. SUMMARY OF THE INVENTION

To meet the above noted and other desires, a revelation of the present invention is brought forth. In a preferred embodiment, the present invention provides a transmission hydraulic control assembly. The transmission hydraulic control assembly includes a valve body providing fluid passages to a controlled pressure control volume, an exhaust and a pressurized supply. The valve body has a planer surface with intersecting portals for the controlled pressure control volume, exhaust and pressurized supply passages. An electronically controlled spool type valve is provided for controlling fluid communication between the controlled pressure control volume and the exhaust and the pressurized supply via the valve body. The valve has a valve sleeve encircling a valve spool. The valve sleeve has portals for the controlled pressure control volume, exhaust and supply pressure passages. The valve sleeve portals intersect the generally valve sleeve planer surface which are aligned with the valve body planer surface portals. A tower is provided projecting from the valve body having a threaded bar bore. A clamping bar is fastener connected to the tower to retain the valve with the valve body while aligning the valve with the valve body. The inventive transmission control hydraulic assembly provides a clamping bar or bracket mounted solenoid which reduces leakage by providing a direct interface between the solenoid sleeve and the valve body that doesn't require a high precision machined valve sleeve cartridge and valve body bore. Simpler fiat surface machining replaces the cylindrical valve body bore/cartridge geometry to provide the solenoid valve, valve body interface.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

The present invention wiil become more fully understood from the detailed description and the accompanying drawings, wherein:

Figure 1 is a plain elevational view of a preferred embodiment transmission hydraulic control assembly according to the present invention;

Figure 2 is top plan view of a valve utilized in the transmission hydraulic control assembly shown in Figure 1 ;

Figure 3 is a top plan view of the transmission hydraulic control assembly shown in Figure 1 ; Figure 4 is a view similar to that of Figure 1 of an alternate preferred embodiment transmission hydraulic control assembly according to the present invention;

Figure 5 is a partial top plan view of a valve body utilized in the transmission hydraulic control assembly shown in Figures 1 and 4; Figure 6 is a top plan view of the transmission hydraulic control assembly shown in Figure 4; and

Figure 7 is an enlarged partial exploded view of portions of the transmission hydraulic control assembly shown in Figure 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

Referring to Figs. 1 , 2, 3 and 5, a transmission hydraulic control assembly 7 is provided. The transmission hydraulic control assembly 7 includes a valve body 10. The valve body 10 provides a fluid passage 12 to a controlled pressure control volume 14 provided by an actuating cylinder of a hydraulic clutch 16 of the vehicle transmission. As shown in Fig. 1 , passage 12 is only shown schematically. It is apparent to those skilled in the art that the passage 12 can be curvilinear having various shapes in three axis to connect a top side 11 of the valve body 10 with a lower side of the valve body 13. Appropriate tubing (not shown) connected with the controlled pressure control volume 14 of the actuator cylinder for the clutch 16. Optionaily, another passage 18 can be provided which additionaliy connects with the controlied pressure controi volume 14. A passage 20 of the valve body (shown schematically) connects the valve body 10 with a hydraulic exhaust or sump 22. A passage 24 (shown schematicaily) connects the top of a valve body with a pressurized fluid supply provided by a pump 26. The hydraulic pump 26 intake is connected with a fluid source provided by the sump 22. The valve body 10 typically accommodates a plurality of controlied pressure control volumes on a transmission which will include various hydrauϋcaliy actuated dutches, brakes, and synchronizer mechanisms. As relatively apparent to those skilled in the art, the pump 26 may be a pressurized fluid source for a plurality of hydraulic mechanisms in the transmission.

The vaive body 10, as mentioned previously, has a top 11 and a bottom surface 13. The bottom surface 13 is typically along the interior of the transmission casing. Slightly elevated from a remainder of the top 11 is a planer surface 30. The valve body 10 is typically fabricated from aluminum, plastic or other suitable materials. The planer surface 30 has an intersecting portal 32 for the pressurized supply. The pianer surface 30 has intersecting portals 34 and 36 connecting with valve body passages 18 and 12 respectively. An intersecting portal 38 connects with the exhaust passage 20.

The transmission hydraulic control assembly 7 also includes a plurality of electronically controlled spool type solenoid valves 40 (only two shown). Each of the solenoid valves 40 has an electrical portion provided by an outer casing 42 which encircles an annular coil bundle 44. The coil bundle 44 is selectively energized by an electronic control unit 46 (see Fig. 1 ). Activation of the coil bundle 44 causes a ferro magnetic armature 47 (shown only schematically) to move against a biasing spring (not shown) or fluid pressure or combination thereof to provoke movement in a valve spool 49. The valve spool 49 is fitted within a cylindrical center of a valve sleeve 48. The valve sleeve 48 exterior has a generally pianer surface 50 (Fig. 1 ). The vaive sleeve 48 also has an exhaust portal 52 which intersects the generally planer surface 50. Additionally, there is provided controlled pressure control voiume portals 54 and 56 which are juxtaposed by a pressurized supply porta! 58. AIi of the aforementioned vaive sleeve portals are intersecting with a generally planer surface 50 and are generally aligned and are provided for mating with the valve body planer surface portais. The spool type valve 40 are provided for controlling fluid communication between the controlied pressure control volume and the exhaust and/or the pressurized supply via the vaive body 10.

A tower 60 is provided having a threaded bore 62. A bracket or clamping bar 70 is held in position on the tower 60 by a fastener 74. When connected to the tower 60, the clamping bar 70 bases out against a top surface 72 of the tower. The clamping bar 70 has a damp section with upward extending arm sections 78. The upward extending arm sections 78 are connected with generally horizontally extending sections 80 and downward extending sections 82. The sections 78, 80 and 82 combine to have trilateral tangential contact with a generally cylindrical portion 86 of the vaive sleeve. The sections 78 and 82 of the clamping bar laterally position the valve sleeve 48 with respect to the tower 60, and accordingly align in a lateral fashion the portals 52, 54, 58 and 56 of the valve sleeve with the portais 38, 34, 32 and 36 of the valve body. The clamping bar 70 when based out against top surface 72 of the tower additionaily causes the section 78, 80 and 82 to be in compression to elastically hoid the solenoid valves 42 to the vaive body 10 in an amount sufficient to withstand vibration and also in an amount of force to minimize, if not totally eliminate, any leakage between the interface of the planer surface 50 of the valve sleeve and the planer surface 30 of the valve body.

In the transmission hydraulic control assembly 7 as provided in Figs. 1 , 2, 3 and 5, axial alignment of the valve sleeve 48 with the vaive body 10 in an axis generally parallel with an axis of extension of the spool 49 can be achieved by alignment with a scribe line or some other axial alignment method.

Referring to Figs. 4, 6 and 7, an alternate preferred embodiment 17 transmission hydraulic control system is provided, items performing similar functions to the transmission hydraulic control system 7 are shown in Figs. 1-3 and 5 are given like numbers. The transmission hydrauϋc contro! system 17 has a vaive body 10 essentiaiiy similar or identical to that previously described. Projecting up from a top surface 11 of the valve body 10 is a tower 160. The tower 160 has a recessed portion 171 allowing it to have axial borders 173. The axial borders 173 are aligned with and receive a mid-portion 175 of the clamping bar 70. The solenoid valves 140 have a vaive sleeve 148 with a recess portion 151. When assembled to the valve body 10 by the damping bar 70, the ends of the clamping bar 177 are placed within the recess 151 abutting the recessed ends 153 of the valve sleeves to axially align the valve sleeves with respect to the valve body 10 thereby axially aiong a direction of the vaive spool 49 aligning the portais 52, 54, 58 and 56 with the portals 38, 34, 32 and 36 respectively of the valve body.

It is apparent to those skilled in the art that the inventive transmission hydraulic contro! system can provide a multitude of towers with a single unitary extended clamping bar if so desired (not shown).

The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.