DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See sections 10 & rule 13)
1. TITLE OF THE INVENTION
A CONTROL SYSTEM AND METHOD FOR HYDRO-SHIFT TRANSMISSION FOR WET MULTIPLE CLUTCH AND INCHING MECHANISMS
2. APPLICANT (S)
NAME NATIONALITY ADDRESS
BEML LIMITED IN BEML Soudha, No 23/1, 4th Main S.R. Nagar, Bengaluru- 560027, Karnataka, India.
3. PREAMBLE TO THE DESCRIPTION
COMPLETE SPECIFICATION

The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF INVENTION:
[001] The present invention relates to the field of control system and method used in hydro-shift transmission. The present invention in particular relates to a control system for wet multiple clutches and inching controls used in hydro-shift transmission.
DESCRIPTION OF THE RELATED ART:
[002] Equipment used in ON and Off-road conditions are operated under load and no-load conditions, combined with speed operations to improve the productivity. Gear shift quality is the major focus in such transmissions and clutch pressure modulation, having fixed modulation using valves and operated by spring, was developed to provide jerk-free gear shifts. However, these valves were only suited specific load conditions and did not provide similar riding comfort under different load and speed conditions.
[003] Also Inching is a special operation in Motor Grader application. This is used to fine control of equipment during grading operation and also cut-off engine power during gear shifting. The existing inching mechanism is through mechanical linkages and mechanical spools.
[004] Reference may be made to the following:
[005] Publication No. EP0207525 relates to a vehicle, for instance a fork lift, in which a hydraulic pump for driving the fork is driven by an engine serving also for moving the vehicle, employing an automatic transmission for movement of the vehicle, is provided with inching control means which control a clutch for separating the movement system and the cargo handling (fork) system.
[006] Patent No. US3085403 relates to hydraulic power transmission systems of the kind in which a plurality of hydraulic motors receive their motive fluid from a common supply.
[007] Patent No. US4790420 relates to a vehicle such as a forklift in which a hydraulic pump for driving the fork is driven by the same engine used to provide motive power to the vehicle.
[008] Publication No. CN205207642 relates to a two fast automatic transmission liquid accuse gear shift systems, the oil pump links to each other with the motor, the oil inlet of oil pump passes through the pipeline and links to each other with the oilcan, it has the relief valve to connect in parallel on the oil -out pipeline of oil pump, first gear shift solenoid valve and second gear shift solenoid valve, the oil -out of relief valve passes through the pipeline and links to each other with the oilcan, the oil -out of first gear shift solenoid valve passes through the left oil pocket of pipe connection gear shift hydro -cylinder, the oil return opening of first gear shift solenoid valve passes through the pipeline and links to each other with the oilcan, the oil -out of second gear shift solenoid valve passes through the right oil pocket of pipe connection gear shift hydro -cylinder, the oil return opening of second gear shift solenoid valve passes through the pipeline and links to each other with the oilcan, and motor, first gear shift solenoid valve pass through the parallelly connected access controller of respective signal line with second gear shift solenoid valve.
[009] Publication No. RU2007104745 relates to a motor car, which can be transformed into a vertical-takeoff-and-landing flying vehicle. The flying motor car includes a motorcar-shape body, steering system, gyrostabiliser, drive chassis, power unit, parachute, retractable twin-finned tail located on each side and lift and propulsion unit.
[010] Publication No. US10753468 relates to auxiliary transmission actuation mechanism in a power transmission unit of a vehicle includes a transmission actuating gear, a gear driven bush, a gear actuating means, a shift fork, a shift rail, a clutch control valve actuating arm, a rail shifting means.
[011] Publication No. US2011297856 relates to a proportional pressure control valve comprising a valve box which has at least three fluid-carrying connections, especially in the form of a pump (P), a user (A) and a reservoir (T) connection, a control piston being guided in a longitudinally displaceable manner inside the valve box for optionally connecting the pump connection (P) to the user connection (A) and the user connection (A) to the reservoir connection (T).
[012] Patent No. US5067687 relates to a proportional pressure control valve is disclosed which may be used for uni-directional or bi-directional fluid flow. An electromagnetic driver mounted in a driver cavity of a housing produces a magnetic flux path in response to a variable input current. The magnitude of the flux path is substantially proportional to the input current. The flux path passes through an armature which is movable within the driver cavity. The armature is connected to a metering spool so that the two move in unison.
[013] Publication No. US2024328117 relates to a hydraulic system of a working machine includes a hydraulic actuator to be driven by a hydraulic fluid, a control valve to perform a switching operation for switching a flow rate of the hydraulic fluid supplied to the hydraulic actuator, and a controller to control the control valve. The control valve includes a solenoid and performs the switching operation in accordance with a current supplied to the solenoid.
[014] Publication No. CN212338136 relates to a hydraulic gear shifting system of an automatic transmission, which comprises a main pressure oil way, a pressure control valve, a first flow control valve, a second flow control valve and a plurality of oil cavities, and an oil outlet of the main pressure oil way is connected with the pressure control valve; an oil outlet of the pressure control valve is respectively connected with oil inlets of the first flow control valve and the second flow control valve; the oil cavities comprise the odd-numbered oil cavity and the even-numbered oil cavity, an oil outlet of the first flow control valve is connected with the odd-numbered oil cavity, and an oil outlet of the second flow control valve is connected with the even-numbered oil cavity.
[015] Publication No. CN106609529 relates to a control arrangement for a work vehicle has a first operator control configured to provide a steering input to turn steered wheels of the vehicle, and a second operator control having two control switches configured to provide a wheel lean input to lean the steered wheels and an articulation input to articulate the chassis of the vehicle. The control switches are positioned on the second operator control so that a single movement of a single finger of an operator's hand applied to the control switches simultaneously initiates the wheel lean input and the articulation input.
[016] Patent No. US10815645 relates to a protection system for a wire harness in a motor grader includes a controller and a sensor. The controller has a processor executing stored commands and a data store with memory architecture containing stored angular orientation values for the circle frame. The sensor is coupled to one or more of the circle frame, the draft frame, and a circle actuator that rotates the circle frame relative to the draft frame.
[017] Publication No. CN103398170 relates to a hydraulic control system for a parallel planetary gear train transmission of an automobile.
[018] Publication No. JP2023044383 relates to appropriately shift from a warm-up mode to warm a hydraulic circuit to a normal mode for normal operation. A work vehicle hydraulic system comprises: a first hydraulic passage 361 which connects a first action valve to first hydraulic equipment; a second hydraulic passage which connects a second action valve to second hydraulic equipment; a third hydraulic passage which connects the first hydraulic passage to the second hydraulic passage; a first hydraulic discharge passage to discharge hydraulic oil in the first hydraulic passage; a second hydraulic discharge passage to discharge hydraulic oil in the second hydraulic passage; and a control device which controls the first action valve and the second action valve.
[019] Publication No. JP2000301961 relates to the transmission of a working vehicle which uses a plurality of speed change hydraulic clutches with the main clutch being of the wet multiple disk type. In this transmission which uses a plurality of speed change hydraulic clutches, the clutch with the large clutch capacity is used as the main clutch. The low-speed hydraulic clutch for shifts between high and low speed is used as the main clutch A.
[020] Publication No. WO9510711 relates to a three-element, three-phase hydrodynamic torque converter having improved structural and hydrodynamic characteristics, and automatic transmissions that use a plurality of such hydrodynamic torque converters as replacements for multiple disc wet clutches or the like to effect transmission ratio changes. The hydrodynamic torque converters use a centrifugal impeller and a centrifugal turbine on the forward axial side of the torque converter, and a centripetal stator mounted to the converter shell on the rearward axial side.
[021] Publication No. EP0315596 relates to a hydraulic operating circuit for friction power-shift clutches (1a-2b) for tractor gearboxes, in which the hydraulic actuators of the clutches are operatively associated with respective valve units which are connected in series and are operated by electronically-controlled piloting means adapted to achieve the combined engagement and disengagement of the clutches for effecting changes of speed ratio without interrupting the transmission of torque.
[022] Publication No. WO2017187221 relates to an automatic clutch and gear shifter, wherein at least one motor controls throttle, clutch and gear (all three) for accomplishing an automatic gear shift. This ensures prefect smooth auto gear shifting without causing any jerk.
[023] Patent No. US8051650 relates to a hydraulic system for actuating a clutch and/or a variable speed drive unit of a belt-driven conical-pulley transmission of a vehicle, such as a commercial vehicle, and having a variable transmission ratio and a torque sensor. The hydraulic system includes at least one hydraulic energy source. A selector and check valve is provided for supplying additional components besides the torque sensor and is connected between the hydraulic energy source, the additional components, and the torque sensor in such a way that the torque sensor includes priority in being supplied with hydraulic medium.
[024] Publication No. EP0250441 relates to a hydraulic control for automatic gear-box for motor vehicles comprises shifting valves for applying a working pressure to the shift couplings/brakes (A, C'). The shifting points of the shifting valves and the working pressure depend on the load of the motor (position of the accelerator pedal) and on the speed and are applied as control pressures (choke and regulation pressures) to the shifting valves.
[025] Publication No. JP2016031095 relates to suppress the overspeed of an engine when there is the abnormality of a hydraulic control mechanism such as to actualize shift-down erroneously responding to a shift-up command in a vehicle mounted with an automatic transmission. A hydraulic control mechanism is selectively switched over between a first state that a hydraulic pressure can be supplied to a first friction fastened element 60 to be fastened at a first transmission gear ratio and a second state that a hydraulic pressure can be supplied to a second friction fastened element 50 to be fastened at a second transmission gear ratio smaller than the first transmission gear ratio.
[026] Publication No. IN9030/DELNP/2007 relates to the modular transmission uses only a pair of small and light hydraulic machines of remarkably improved volumetric efficiency with pistons having body portions substantially as long as the axial length of the respective cylinders in which they reciprocate.
[027] Patent No. US3719108 relates to a hydraulic control system for the automatic transmission of a vehicle, an arrangement is provided for controlling the supply and release of pressurized oil to a first hydraulic servo for operating the vehicle under high-speed conditions and to a second hydraulic servo for operating the vehicle under low-speed conditions. The hydraulic control system includes oil passages connected to the first and second hydraulic servos, a speed-change valve, a timing valve and a manual valve. Based on a signal determined by the running speed of the vehicle the speed-change valve controls the flow of pressurized oil to the first hydraulic servo. The timing valve is in communication with both the first and second hydraulic servos and opens and closes flow to the second hydraulic servo.
[028] Publication No. GB537040 relates to an exhaust-pipe system tuned to create oscillations supporting scavenging and charging is variable to suit differing speeds and loads. The exhaust conduit may traverse chambers to which it is open in varying degree depending on the position of sleeves. The chamber volume may also be varied by the introduction of water. Variation may be effected automatically under control of speed or load conditions or exhaust temperature through mechanical, electric or hydraulic transmission.
[029] Publication No. GB1205950 relates to a hydrostatic transmission having a variable displacement swash-plate pump connected in closed circuit with a variable displacement swash-plate motor, and hydraulic servomechanisms selectively controlling the pump and motor swash-plate inclinations, an engine driven auxiliary pump having low and high pressure outlets respectively supplies make-up fluid to the power circuit from the outlet at a pressure limited by a relief valve and fluid to the servo-mechanisms from the outlet 20 at a higher pressure limited by a relief valve.
[030] Publication No. GB711534 relates to a multi-valve unit for use in a hydraulic control system, comprises a plurality of manually-operable valves each controlling its own motor and each comprising a housing having an axial bore slidably mounting a valve plunger, at least one transverse passage intersecting the bore and opening into recesses on opposite faces of the housing and a passage extending across the housing between the faces without intersecting the bore and communicating with the transverse passage through the recesses. As shown in Fig. 7, the multi-valve unit, comprises control valves controlling double-acting motors respectively, a control valve controlling a single-acting motor, supply and return connections and an adapter block.
[031] Publication No. CN113790251 relates to a vehicle power system, an optimization method and a control method. An output shaft of an engine is coaxially connected with an input shaft of an automatic gearbox through a hydraulic transmission, and an output shaft of the automatic gearbox is connected with a vehicle through a main speed reducer.
[032] The article entitled “Technical trend of the power shift transmission (PST) of agricultural tractor” by Md Abu Ayub Siddique, Taek-Jin Kim, and Yong-Joo Kim; koreascience talks about the agricultural tractors are being automation and intelligence due to enhance working efficiency, minimize driving effort, and adjust precision agriculture. Tractors are designed to deliver high traction forces at low speed. It is important for a powertrain to supply continuous power to the driving axles during operations. That is why several researchers and manufacturers developed various power transmission systems. There are two types of transmissions for tractor such as manual transmission (MT), automatic transmission (AT). The AT is called auto or self-shifting transmission or n-speed transmission, which changes gear ratios at various steps or automatically. The AT of the tractor is also two types, which are step and stepless transmission. On the basis of variable transmissions, the speeds may be variable in discrete steps or continuously variable within a range. The step-variable transmissions usually employ either gears or chains and provide fixed speed ratios with no-slip (Xu et al. 2018). The step-variable transmission includes the two types of power-shift transmission (PST) and dual-clutch transmission (DCT). According to Blagonravov et al., (2016), the stepless transmissions use either belts, chains, or rolling-contact bodies. It is classified as the hydro-mechanical transmission (HMT) and hydrostatic transmission (HST). This study deals with the power-shift transmission (PST).
[033] The article entitled “Shifting control system design for hydraulic mechanical transmission of wet clutch” by Yang Zhida; Wang Liyong; Chen Tao; 13th IEEE International Conference on Electronic Measurement & Instruments (ICEMI); 20-22 October 2017 talks about the control system of wet clutch hydraulic mechanical gearbox. The system is based on the CAN bus communication protocol to write the control signal of the shift signal. It is designed 6 forward gear and 1 reverse gear stalls for the gearbox to control. The local / remote switch is achieved in hydraulic mechanical gearbox. The actual operation results of the shift control system show that the system is stable, reliable and accurate in parameter measurement. The feasibility of the local / remote control method is verified, and the control system has practical application value.
[034] The article entitled “High strength main frame and tough power train make it easy to complete heavy-duty jobs” by Komatsu Ltd. Japan; Komatsu latinoamerica; 2016 talks about the main frame is a flanged box section structure. Side plates have been added to increase strength and thereby improve durability. This durable structure guards against bending and twisting forces generated by the load on the blade. Pilot check valves are provided on blade lift, tire leaning, and articulation and drawbar side shift circuit mechanisms, thus preventing the GD663A from hydraulic drift. The GD663A provides high accuracy surface finishing - a vital role of the motor grader. Double-acting piston type hydraulic cylinders: two for blade lifting, one for drawbar side shifting, one for blade side shifting, one for front wheel leaning, two for front wheel steering and two for frame articulation. Pilot check valves assure positive cylinder action (excluding a blade side shift cylinder). 3-spool and 4-spool type control valves for work equipment controls. Relief valve installed on control valves for sure control.
[035] The article entitled “Common hydraulic valves - the proportional pressure valve” by valmet; Jan 26, 2021 talks about the proportional valves are commonly used to control pressure to a cylinder or hydraulic motor. They provide infinite spool positioning and thus infinitely adjustable flow volumes. The resulting flow or pressure output is proportional to the input change, i.e. triple the input produces triple the output. They are controlled electronically either by sending a voltage (10V to 10V) or current signal (420mA) to the valve depending on model of valve. The electrical signal supplied to the solenoid coils creates a variable force that overcomes a spring force and shifts the main spool enough to allow supply pressure (P) to flow to port A or B.
[036] The article entitled “What is proportional control valve?” by hi-des; 2022 talks about the proportional control valves provide variable hydraulic outputs proportional to an electric input signal in direction, flow, or pressure. The electromagnetic output force of the solenoid is proportional to the current flowing through the coil. Proportional control valves are used in a variety of applications to control the flow or pressure of fluids. Proportional valves are used in a variety of applications, such as controlling the flow or pressure of fluids. A proportional valve can be either directional or non-directional. Proportional valves are widely used in hydraulic systems and produce variable hydraulic outputs proportional to an electric input signal in direction, flow, or pressure. In hydraulic systems, a proportional valve consists of an actuator and a two-port or three-port valve.
[037] The article entitled “Hydroshift system” by Grupo Tatoma; tatomaamerica; 2025 talks about the transmission system, used on the trailered vertical feed mixers, that allows to modify the rotational speed of the augers manually, and, as well, by detecting the pressure/weight of the mixing product inside the tub.
[038] Prior art clutch engagement has fixed type modulation with the help of mechanical valves operated by spring stiffness. The existing inching mechanism is through mechanical linkages and mechanical spools.
[039] In order to overcome above listed prior art, the present invention provides a closed loop adaptive clutch pressure control system for smooth gear shifting using proportional pressure control modulating valve and electronic type Inching Control system for Hydro-shift transmission. The present invention provides an improvement in clutch engagement system and method for various type wet multiple clutches and electronic inching controls used in hydro-shift transmission.
OBJECTS OF THE INVENTION:
[040] The principal object of the present invention is to provide a control system and method for hydro-shift transmission for wet multiple clutch and inching mechanisms.
[041] Another object of the present invention is to provide a proportional pressure controlled modulating valve for hydro-shift transmission clutch control provides smooth jerk free gear shift by using variable modulation.
[042] Yet another object of the present invention is to introduce in¬built self-diagnostic system along with interlocks for hydro-shift transmission safety and directly enhances the reliability.
[043] Still another object of the present invention is to establish closed loop adaptive type clutch pressure control logic with clutch overlapping methodology to avoid the torque cut off during gear shifting.
SUMMARY OF THE INVENTION:
[044] The present invention relates to a control system and method for hydro-shift transmission for wet multiple clutch and inching mechanisms. The Proportional pressure controlled modulating valve for hydro-shift transmission clutch control provides smooth jerk free gear shift by using variable modulation.
[045] Gear Shifting Modulation time optimized in all the clutch engagement combination around 30% compare with existing system with the help of Proportional pressure controlled modulating valve with variable clutch modulation and filling the clutch using quick fill valve.
[046] The present invention involves closed loop electronic inching pedal and proportional controlled inching mechanism with improved method for smooth clutch engagement during inching operation.
BREIF DESCRIPTION OF THE INVENTION
[047] It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments.
[048] Figure 1 shows optimized proportional pressure control modulative valve assembly with hydro-shift transmission integration details.
[049] Figure 2 shows isometric view of an optimized proportional pressure control modulative valve assembly.
[050] Figure 3 shows a clutch control system 300 (hereinafter referred to as the system 300) for hydro-shift transmission.
[051] Figure 4 illustrates Test Setup for ensuring the characteristics of Relief and Cooler Bypass Valve.
[052] Figure 5 illustrates the control system for hydro-shift transmission.
[053] Figure 6 illustrates the clutch modulation optimization compare with the prior art.
[054] Figure 7 explains electronics type inching control system compare with prior art.
DETAILED DESCRIPTION OF THE INVENTION:
[055] The present invention provides a control system and method for hydro-shift transmission for wet multiple clutch and inching mechanisms. The Proportional pressure controlled modulating valve for hydro-shift transmission clutch control provides smooth jerk free gear shift by using variable modulation.
[056] Wet multiple clutches and an inching control system for Hydro-shift transmission assembly comprising, a wet-multiple clutches an inching control system for hydro-shift transmission comprises a transmission power train selectively coupled to a plurality of gears via at least one clutch. The control system further includes an optimized proportional pressure-controlled modulation valve (PPCMV) assembly coupled to the at-least one clutch, a manifold block which is integrated with relief valve and cooler by-pass valve. The PPCMV assembly includes at least one of a proportional cartridge type valve and a fill valve. The PPCMV (1B) assembly is configured to regulate the clutch oil pressure in the at least one clutch by means of different combinations of the proportional valve and the fill valve for different predetermined volumes of the at least one clutch. An electronic transmission control circuit connected to the PPCMV assembly is configured to control the PPCMV assembly and consequently the at least one clutch. The oil inlet from filter (1J) is connected via manifold block (1D) and circulating to the transmission control valve inlet (1H).
[057] The relief valve and cooler by-pass valve which is the part of manifold block (1D) ensure the transmission inlet pressure by relief setting. The relief valve relieved oil flow is circulating to Transmission lubrication thru’ lubrication line (1G). Once set pressure attained in cooler by-pass valve, the flow will be circulating to transmission oil cooler (1K). The overall transmission control valve assembly (1A) mounted on Transmission housing (1E) and further oil flow to clutch housing will circulating thru’ clutch housing to wet-multiple clutch actuation.
[058] A wet-multiple clutches an inching control system for hydro-shift transmission comprises a transmission power train selectively coupled to a plurality of gears via at least one clutch. The control system further includes an optimized proportional pressure-controlled modulation valve (PPCMV) assembly coupled to the at-least one clutch, a manifold block which is integrated with relief valve and cooler by-pass valve. The PPCMV assembly includes at least one of a proportional cartridge type valve and a fill valve. The PPCMV (1B) assembly is configured to regulate the clutch oil pressure in the at least one clutch by means of different combinations of the proportional valve and the fill valve for different predetermined volumes of the at least one clutch. An electronic transmission control circuit connected to the PPCMV assembly is configured to control the PPCMV assembly and consequently the at least one clutch. The oil inlet from filter (1J) is connected via manifold block (1D) and circulating to the transmission control valve inlet (1H).
[059] The relief valve and cooler by-pass valve which is the part of manifold block (1D) ensure the transmission inlet pressure by relief setting. The relief valve relieved oil flow is circulating to Transmission lubrication thru’ lubrication line (1G). Once set pressure attained in cooler by-pass valve, the flow will be circulating to transmission oil cooler (1K). The overall transmission control valve assembly (1A) mounted on Transmission housing (1E) and further oil flow to clutch housing will circulating thru’ clutch housing to wet-multiple clutch actuation. The optimized Proportional Pressure Control Modulative Valve Assembly with Hydro-shift Transmission Integration details mentioned in figure 1. The Isometric view of an optimized Proportional Pressure Control Modulative Valve Assembly mentioned in figure 2.
[060] Figure 3 illustrates a clutch control system 300 (hereinafter referred to as the system 300) for hydro-shift transmission for in accordance with an embodiment of the present disclosure. Speed and torque demand of vehicle will be satisfied with the help of at-least using combination of three clutches from one from speed clutch, another from range clutch and from direction clutch.
[061] The system 300 comprises a transmission power train selectively coupled to a plurality of gears via at least three clutches of (3e, 3f,3g,3h,3k,3m,3n,3p) proportional pressure-controlled modulation valve (PPCMV) assembly (1B) coupled to the at least three clutch (3e, 3f,3g,3h,3k,3m,3n,3p). The at least three clutches (3e, 3f,3g,3h,3k,3m,3n,3p) has a predetermined volume for holding clutch oil.
[062] The PPCMV assembly (1B) includes at least one of a proportional valve (3b) and a fill valve (3a). The PPCMV assembly (1B) is configured to regulate the clutch oil pressure in the at least three clutches (3e, 3f,3g,3h,3k,3m,3n,3p) by means of different combinations of the proportional valve (3b) and the fill valve (3a) for different predetermined volumes of the at least three clutches (3e, 3f,3g,3h,3k,3m,3n,3p). Each PPCMV assembly (1B) integrated with pressure transducer (3c) for provided feedback to control unit.
[063] In an embodiment, for hydro-shift transmission operation the at least one clutch (3e, 3f,3g,3h,3k,3m,3n,3p) is selected from a group of range clutches including H clutch (3p) and an L clutch (3n) each coupled to individual PPCMV (1B) assemblies respectively, and a group of speed clutches (3m,3k,3h,3g) coupled to four individual PPCMV assemblies (1B) and further direction clutches Forward and Reverse clutches (3e,3f) coupled to individual PPCMV (1B). The oil from sump is circulating thru’ gear pump with the required flow rating and passing to the transmission control valve thru’ filter element (1p) and passing thru’ manifold block (1d) which consists of relief valve (1q) and cooler bye-pass valve (1r). Further oil is passing to transmission control valve to additional non-bypass filter element (1u) for ensuring the oil cleanliness.
[064] Figure 4 illustrates Test Setup for ensuring the characteristics of Relief and Cooler Bypass Valve. External hydraulic pack (4c) used to provide the variable input flow with flow control valve (4f) to thru’ manifold block (1d) which consists of relief valve (1q) and cooler bye-pass valve (1r). Two flow meters connected to pump flow line to inlet flow (4d) and relief flow line flow to cooler line (4f). Pressure gauges (4e) connected in 3 places for real time pressure measurement and ensure the performance characteristics of relief valve (1q) and cooler by-pass valve (1r). Relief valve set to 31 bar at minimum flow of 30 LPM and with-out back pressure at cooler line circuit. Temperature maintained as 60 ºC ~ 80 ºC for the overall testing ranges. Up-to maximum flow conditions performance ensured and accordingly the optimized hydraulic circuit has been finalized.
[065] Figure 5 illustrates the control system for hydro-shift transmission which consists of range clutch (Group A-PPCMV), speed clutch (Group B-PPCMV) and direction clutch (Group C-PPCMV) combination for ensuring vehicle tractive effort conditions based on terrain conditions. The gear shifter signal will be provided to controller and accordingly clutch combination will be engaged and required output will be obtained based on load demand. Further inching control logics provided to controller and accordingly feedback signal sent to clutch system for clutch engagement.
[066] Figure 6 illustrates the clutch modulation optimization compare with the prior art using the optimized PPCMV assembly unit. 30% overall modulating time and responsiveness improved compare with the prior art at an engine Low Idle and high idle Speed Operating Conditions with the help of present invention.
[067] Figure 7 explains electronics type inching control system compare with prior art. Present invention removes the mechanical control valve unit (700) which contains inching spool (710) which controls thru’ inching pedal and controlling the oil flow from the modulating valve oil chamber (730) to drain port (720) as per the mechanical spool stroke position. Prior art inching control graph explained in (740).
[068] Present invention introduced electronic control module (750), where inching mechanism is controlled thru’ electronic inching pedal position signal to controller and accordingly partial clutch engagement with predefined period will take place with optimum clutch modulation time considering with inching pedal position for forward or reverse clutch (3e or 3f) as per the demand signal. Present invention electronic inching control graph mentioned in (760).
[069] Present invention of Proportional pressure controlled modulating valve for hydro-shift transmission clutch control provides smooth jerk free gear shift by using variable modulation. The present invention involves closed loop electronic Inching pedal and proportional controlled inching mechanism with program logics for smooth clutch engagement during inching operation. Also, it eliminates the mechanical spools and the inching operating enabled thru’ an electronics control.
[070] Gear shifting modulation time optimized in all the clutch engagement combination around 30% compare with existing system with the help of Proportional pressure controlled Modulating Valve with variable clutch modulation and filling the clutch using quick fill valve.
[071] Closed loop adaptive type clutch pressure control logic with Clutch overlapping methodology established to avoid the torque cut off during gear shifting.
[072] Proportionally controlled Inching mechanism is a special operation in motor grader application. This is used to fine control of equipment during grading operation and also cut-off engine power during gear shifting. The present invention involves closed loop electronic Inching pedal and proportional controlled inching mechanism with improved method for smooth clutch engagement during inching operation.
[073] Individual mono block type PPCMV assembly is introduced for each clutch units (speed, range and direction clutches) combined with feedback systems. External mounting type relief cum cooler by-pass valve introduced with compact envelope sizing to ensure the predefined flow requirement.
[074] Gear shifting modulation time optimized in all the clutch engagement combination is 30% with the help of proportional pressure controlled modulating valve with variable clutch modulation and filling the clutch using quick fill valve. The present invention introduces closed loop electronic inching pedal and proportional controlled inching mechanism with improved method for smooth clutch engagement during inching operation. The response time during inching operation parametrically smoothly controlled with the help of feedback system.
[075] Safety diagnostics interlocks adapted during inching and transmission clutch engagements for healthy monitoring of overall control systems.
[076] Numerous modifications and adaptations of the system of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the true spirit and scope of this invention.
,CLAIMS:WE CLAIM:
1. A control system and method for hydro-shift transmission for wet multiple clutch and inching mechanisms-
a) a transmission power train selectively coupled to a plurality of gears via at least one clutch wherein the mono block type individual clutch control system enabled for smooth gear shifting and closed loop feedback system enabled for transmission healthy monitoring system (THMS).
b) an optimized proportional pressure-controlled modulation valve (PPCMV) assembly (1B) coupled to the at-least one clutch, a manifold block which is integrated with relief valve and cooler by-pass valve characterized in that at least one of a proportional cartridge type valve and a fill valve wherein proportional pressure-controlled modulation valve (PPCMV) enabled from regular ON-OFF to modular type
c) An electronic transmission control circuit connected to the PPCMV assembly is configured to control the PPCMV assembly and consequently the at least one clutch wherein the oil inlet from filter (1J) is connected via manifold block (1D) and circulating to the transmission control valve inlet (1H).
2. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 1, wherein the relief valve and cooler by-pass valve which is the part of manifold block (1D) ensure the transmission inlet pressure by relief setting.
3. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 2, wherein the relief valve relieved oil flow is circulating to Transmission lubrication through lubrication line (1G), once set pressure attained in cooler by-pass valve, the flow will be circulating to transmission oil cooler (1K) wherein the overall transmission control valve assembly (1A) mounted on Transmission housing (1E) and further oil flow to clutch housing will circulating thru’ clutch housing to wet-multiple clutch actuation.
4. A clutch control system 300 for hydro-shift transmission comprises a transmission power train selectively coupled to a plurality of gears via at least three clutches of (3e, 3f,3g,3h,3k,3m,3n,3p) proportional pressure-controlled modulation valve (PPCMV) assembly (1B) coupled to the at least three clutch (3e, 3f,3g,3h,3k,3m,3n,3p) and at least three clutches (3e, 3f,3g,3h,3k,3m,3n,3p) has a predetermined volume for holding clutch oil wherein the PPCMV assembly (1B) includes at least one of a proportional valve (3b) and a fill valve (3a) is configured to regulate the clutch oil pressure in the at least three clutches (3e, 3f,3g,3h,3k,3m,3n,3p) by means of different combinations of the proportional valve (3b) and the fill valve (3a) for different predetermined volumes of the at least three clutches (3e, 3f,3g,3h,3k,3m,3n,3p).
5. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 4, wherein the PPCMV assembly (1B) integrated with pressure transducer (3c) for provided feedback to control unit.
6. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 1 and 4, wherein the hydro-shift transmission operation includes at least one clutch (3e, 3f,3g,3h,3k,3m,3n,3p) is selected from a group of range clutches including H clutch (3p) and an L clutch (3n) each coupled to individual PPCMV (1B) assemblies respectively, and a group of speed clutches (3m,3k,3h,3g) coupled to four individual PPCMV assemblies (1B) and further direction clutches Forward and Reverse clutches (3e,3f) coupled to individual PPCMV (1B), oil from sump is circulating thru’ gear pump with the required flow rating and passing to the transmission control valve thru’ filter element (1p) and passing thru’ manifold block (1d) which consists of relief valve (1q) and cooler bye-pass valve (1r) and further oil is passing to transmission control valve to additional non-bypass filter element (1u) for ensuring the oil cleanliness.
7. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 1 and 4, wherein the control system for hydro-shift transmission consists of range clutch (Group A-PPCMV), speed clutch (Group B-PPCMV) and direction clutch (Group C-PPCMV) combination for ensuring vehicle tractive effort conditions based on terrain conditions., providing gear shifter signal to controller and accordingly engaging clutch combination and obtaining required output based on load demand.
8. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 1 and 4, wherein the invention removes the mechanical control valve unit (700) which contains inching spool (710) which controls through’ inching pedal and controlling the oil flow from the modulating valve oil chamber (730) to drain port (720) as per the mechanical spool stroke position. Prior art inching control graph explained in 740.
9. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 1, wherein the PPCMV assembly is configured to regulate the clutch oil pressure in the at least one clutch by means of different combinations of the proportional valve and the fill valve for different predetermined volumes of the at least one clutch.
10. The control system for hydro-shift transmission for wet multiple clutch and inching mechanisms, as claimed in claim 1, wherein inching lever mechanism replaced with the help of electronic control inching control systems with interlock configuration.