Control system for a multi-speed transmission and method thereof

Abstract

An electro-hydraulic control system for a multi-speed transmission having a plurality of torque transmitting mechanisms includes a controller for operatively controlling the transmission, a fluid source for supplying hydraulic fluid, and a plurality of torque transmitting mechanisms operatively selectable between a stressed and unstressed condition to achieve a plurality of ranges including at least one reverse, a neutral, and a plurality of forward ranges. The system includes a plurality of trim systems having a pressure control solenoid and a trim valve. The system can also include one or more shift valves disposed in fluid communication with the fluid source and movable between a stroked and an un-stroked position. In any given range, only two of the plurality of torque transmitting mechanisms can be stressed. Further, three of the plurality of pressure control solenoids are normally high solenoids and the remaining solenoids are normally low solenoids.

Description

[0001] Related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 527,202, filed June 30, 2017, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a method for controlling a transmission system, and more particularly to a method for controlling hydraulic fluid for a multi-stage transmission. Background Technology

[0004] Multi-stage transmissions utilize numerous friction clutches or brakes, planetary gear sets, shafts, and other components to achieve multiple gear ratios or speed ratios. The transmission architecture—the package or layout of the aforementioned components—is determined based on cost, size, packaging constraints, and desired ratios. A control system is required to manage these components and provide the desired shift quality. Furthermore, to improve fuel economy and for other reasons, with an increased range, the control system must ensure that the correct clutch or brake is engaged within any given range and further provide fault range in the event of a power failure. The complexity of the control system continues to increase with the increased forward and reverse gear ranges for any given multi-stage transmission. Summary of the Invention

[0005] In one embodiment of this disclosure, an electro-hydraulic control system for a multi-stage transmission includes: a controller for operably controlling the transmission; a fluid source for supplying hydraulic fluid; a plurality of torque transmission mechanisms operably selectable between a stressed and unstressed state to achieve a plurality of ranges including at least one reverse gear, neutral gear, and a plurality of forward gear ranges, wherein in any of the plurality of forward gear ranges, only two of the plurality of torque transmission mechanisms are in the stressed state; a plurality of fine-tuning systems electrically connected to the controller and fluidly connected to the fluid source, wherein each of the plurality of fine-tuning systems includes a pressure-controlled solenoid valve and a fine-tuning valve; a plurality of shift valves, each configured to be fluidly connected to the fluid source and configured to move between a traveling position and an untraveled position, the plurality of shift valves including at least a first shift valve, a second shift valve, and a third shift valve; and a first shift solenoid valve configured to be electrically connected to the controller. The first shift solenoid valve is operablely controllable between energized and de-energized states to control the movement of the first and second shift valves; the second shift solenoid valve, configured to be electrically connected to the controller, is operablely controllable between energized and de-energized states to control the movement of the third shift valve; wherein, in a first range of the plurality of forward gear ranges, the first torque transmission mechanism of the plurality of torque transmission mechanisms is in a stressed state, and in a second range of the plurality of forward gear ranges, the first torque transmission mechanism is in a de-stressed state; wherein, during shifting from the first range to the second range, the hydraulic fluid applying force to the first torque transmission mechanism is discharged through a first discharge line and a second discharge line, the first and second discharge lines being parallel to each other; further, wherein the first discharge line has no flow restriction, and the second discharge line includes at least one flow restriction.

[0006] In one example of this embodiment, the first discharge line is shorter than the second discharge line. In a second example, the discharge valve is flowably connected to the first torque transmission mechanism. In a third example, the first discharge line is defined between the discharge valve and the first torque transmission mechanism. In a fourth example, only the third shift valve is positioned along the first discharge line located between the discharge valve and the first torque transmission mechanism. In a fifth example, the third shift valve is in a traveling position within the first range; and the third shift valve is in a non-traveling position within the second range.

[0007] In a sixth example, in its traveling position, the third shift valve obstructs the first discharge line. In a seventh example, a first discharge valve is flowably connected to the first discharge line; a second discharge valve is flowably connected to the second discharge line, the second discharge valve being located away from the first discharge valve. In an eighth example, the first discharge line is defined between the first discharge valve and the first torque transmission mechanism; the second discharge line is defined between the second discharge valve and the first torque transmission mechanism. In a ninth example, only the third shift valve is positioned along the first discharge line located between the first discharge valve and the first torque transmission mechanism. In another example, the second shift valve and the first fine-tuning system of the plurality of fine-tuning systems are arranged along the second discharge line. In yet another example, a booster valve is configured to be in direct fluid communication with the first fine-tuning system, wherein hydraulic fluid discharged from the first torque transmission mechanism flows along the second discharge line through the second shift valve, the first fine-tuning system, and the booster valve. In yet another example, at least three of the plurality of pressure-controlled solenoid valves include normally high solenoid valves, and the remaining pressure-controlled solenoid valves include normally low solenoid valves.

[0008] In another embodiment of this disclosure, an electro-hydraulic control system for a multi-stage transmission includes: a controller for operable control of the transmission; a fluid source for supplying hydraulic fluid; a plurality of torque transmission mechanisms operablely selectable between a stressed and unstressed state to achieve a plurality of ranges including at least one reverse gear, neutral gear, and a plurality of forward gear ranges, wherein in any of the plurality of forward gear ranges, only two of the plurality of torque transmission mechanisms are in the stressed state; a plurality of fine-tuning systems electrically connected to the controller and fluidly connected to the fluid source, wherein each of the plurality of fine-tuning systems includes a pressure-controlled solenoid valve and a fine-tuning valve; and a plurality of shift valves, each configured to be fluidly connected to the fluid source and configured to move between a traveling position and an untraveled position, the plurality of shift valves including at least one... The controller includes a first shift valve, a second shift valve, and a third shift valve; a first shift solenoid valve, configured to be electrically connected to the controller, which is operably controllable between energized and de-energized states to control the movement of the first and second shift valves; a second shift solenoid valve, configured to be electrically connected to the controller, which is operably controllable between energized and de-energized states to control the movement of the third shift valve; and a plurality of pressure switches, configured to be electrically connected to the controller, wherein each pressure switch is in a pressurized state or a venting state; further, wherein the controller detects the position of the first shift valve by the state of the first pressure switch, detects the position of the second shift valve by the state of the second pressure switch, and detects the position of the third shift valve by the state of the third pressure switch.

[0009] In one example of this embodiment, in a first range of the plurality of forward gear ranges, the first torque transmission mechanism of the plurality of torque transmission mechanisms is in a stressed state, and in a second range of the plurality of forward gear ranges, the first torque transmission mechanism is in a non-stressed state; during the shift from the first range to the second range, the hydraulic fluid that applies force to the first torque transmission mechanism is discharged through a first discharge line and a second discharge line, the first and second discharge lines being parallel to each other; further, the first discharge line has no flow restriction, and the second discharge line includes at least one flow restriction.

[0010] In the second example, the third pressure switch is in the pressurized state in the first range and in the venting state in the second range. In the third example, the third shift valve is in its traveling position in the first range and in its non-traveling position in the second range.

[0011] In another embodiment of this disclosure, an electro-hydraulic control system for a multi-stage transmission includes: a controller for operable control of the transmission; a fluid source for supplying hydraulic fluid; a plurality of torque transmission mechanisms operablely selectable between a stressed and unstressed state to achieve a plurality of ranges including at least one reverse gear, neutral gear, and a plurality of forward gear ranges, wherein in any of the plurality of forward gear ranges, only two of the plurality of torque transmission mechanisms are in the stressed state; a plurality of fine-tuning systems electrically connected to the controller and fluidly connected to the fluid source, wherein each of the plurality of fine-tuning systems includes a pressure-controlled solenoid valve and a fine-tuning valve; and a plurality of shift valves, each configured to be fluidly connected to the fluid source and configured to move between a traveling position and an untraveled position, the plurality of shift valves including at least a first shift valve. The system comprises a stop valve, a second shift valve, and a third shift valve; wherein when the third shift valve is in its non-advanced position, the third shift valve blocks fluid communication between the fluid source and at least the first torque transmission mechanism and the second torque transmission mechanism among the plurality of torque transmission mechanisms; in a first range of the plurality of forward gear ranges, the first torque transmission mechanism is in a stressed state, and in a second range of the plurality of forward gear ranges, the first torque transmission mechanism is in an unstressed state; during a shift from the first range to the second range, the hydraulic fluid exerting force on the first torque transmission mechanism is discharged through a first discharge line and a second discharge line, the first and second discharge lines being parallel to each other; further, wherein the first discharge line has no flow restriction, and the second discharge line includes at least one flow restriction.

[0012] In one embodiment, the third shift valve is located in a traveling position within the first range and in a non-traveling position within the second range, wherein in its traveling position, the third shift valve blocks the first discharge line. In another embodiment, the system includes: a first shift solenoid valve electrically connected to the controller, the first shift solenoid valve being operably controlled between energized and de-energized states to control the movement of the first and second shift valves; and a second shift solenoid valve electrically connected to the controller, the second shift solenoid valve being operably controlled between energized and de-energized states to control the movement of the third shift valve; wherein the controller is electrically connected to each of the pressure control solenoid valves and the first and second shift solenoid valves of the plurality of fine-tuning systems to operably shift gears between the first and third ranges of the plurality of forward gear ranges, wherein during the shift from the first range to the third range, the second range is skipped. Attached Figure Description

[0013] The foregoing aspects of this disclosure and how they are obtained will become more apparent from the following description of embodiments thereof, taken in conjunction with the accompanying drawings, and the disclosure itself will be better understood, wherein:

[0014] Figure 1 These are block diagrams and schematic diagrams illustrating one embodiment of a powertrain system;

[0015] Figure 2 This is a partial control diagram of a multi-stage transmission system;

[0016] Figure 3 In reverse gear Figure 2 A schematic diagram of the hydraulic control system;

[0017] Figure 4 In neutral or parked Figure 2 A schematic diagram of the hydraulic control system;

[0018] Figure 5 It is in the first range Figure 2 An embodiment of the hydraulic control diagram of the system;

[0019] Figure 6 It is in the first range Figure 2 Another embodiment of the hydraulic control diagram of the system;

[0020] Figure 7 It is in the second range Figure 2 A schematic diagram of the hydraulic control system;

[0021] Figure 8 It is in the third range Figure 2A schematic diagram of the hydraulic control system;

[0022] Figure 9 It is in the fourth range Figure 2 A schematic diagram of the hydraulic control system;

[0023] Figure 10 It is in the fifth range Figure 2 A schematic diagram of the hydraulic control system;

[0024] Figure 11 It is in the sixth range Figure 2 A schematic diagram of the hydraulic control system;

[0025] Figure 12 It is in the seventh range Figure 2 A schematic diagram of the hydraulic control system;

[0026] Figure 13 It is in the eighth range Figure 2 A schematic diagram of the hydraulic control system;

[0027] Figure 14 It is in the ninth range Figure 2 A schematic diagram of the hydraulic control system;

[0028] Figure 15 It is within the first power outage range Figure 2 A schematic diagram of the hydraulic control system;

[0029] Figure 16 It is within the second power outage range Figure 2 A schematic diagram of the hydraulic control system;

[0030] Figure 17 It is within the third power outage range Figure 2 A schematic diagram of the hydraulic control system;

[0031] Figure 18 This is an embodiment of a schematic diagram of the first shift valve;

[0032] Figure 19 This is a schematic diagram of one embodiment of the second shift valve;

[0033] Figure 20 This is a schematic diagram of one embodiment of the third shift valve;

[0034] Figure 21 yes Figure 2 An example of the mechanization of a multi-stage transmission system;

[0035] Figure 22 yes Figure 2 An example of a shift availability table for a multi-stage transmission system; and

[0036] Figure 23 Is Figure 3-17 A diagram illustrating different fluid lines or paths in a hydraulic control system.

[0037] Use the corresponding reference numerals to indicate the corresponding parts that span several views. Detailed Implementation

[0038] The embodiments of this disclosure described below are not intended to be exhaustive, or to limit this disclosure to the precise forms disclosed in the following detailed description. Rather, the embodiments were chosen and described so that those skilled in the art may understand and comprehend the principles and practice of this disclosure.

[0039] The terminology used herein is for the purpose of describing particular illustrative embodiments only and is not intended to limit this disclosure. As used herein, the singular forms “a,” “an,” and “described” are also intended to include the plural forms unless the context clearly indicates otherwise. Similarly, the plural forms may be used to describe particular illustrative embodiments, in which case the singular forms may also apply. The terms “comprising,” “including,” or “having” are inclusive and therefore specify the presence of the said feature, integral, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as requiring performance in a particular order discussed or described, unless specifically indicated otherwise. It should also be understood that additional or alternative steps may be used.

[0040] See now Figure 1 This illustration shows a block diagram and schematic diagram of an illustrative embodiment of a vehicle system 100 having a drive unit 102 and a transmission 118. In the illustrative embodiment, the drive unit 102 may include an internal combustion engine, a diesel engine, an electric motor, or other power generating device. The drive unit 102 is configured to rotatably drive an output shaft 104, which is coupled to an input shaft or pump shaft 106 of a conventional torque converter 108. The input shaft or pump shaft 106 is coupled to an impeller or pump 110 rotatably driven by the output shaft 104 of the drive unit 102. The torque converter 108 further includes a turbine 112 coupled to a turbine shaft 114, which is coupled to or integrated with a rotatable input shaft 124 of the transmission 118. The transmission 118 may also include an internal pump 120 for establishing pressure within different flow lines of the transmission 118 (e.g., main lines, lubrication lines, etc.). Pump 120 can be driven by shaft 116, which is connected to the output shaft 104 of drive unit 102. In this configuration, drive unit 102 can transmit torque to shaft 116 to drive pump 120 and build up pressure in different lines of transmission 118.

[0041] The transmission 118 may include a planetary gear train 122 having a plurality of automatically selectable gears. The output shaft 126 of the transmission 118 is coupled to or integral with a drive shaft 128 and rotatably drives the drive shaft 128, which is coupled to a conventional universal joint 130. The universal joint 130 is coupled to and rotatably drives an axle 132 having wheels 134A and 134B mounted to each end thereto. The output shaft 126 of the transmission 118 drives wheels 134A and 134B in a conventional manner via the drive shaft 128, the universal joint 130, and the axle 132.

[0042] A conventional lock-up clutch 136 is connected between pump 110 and turbine 112 of torque converter 108. The operation of torque converter 108 is conventional, but it can also operate in a so-called "torque converter" mode under certain operating conditions (such as vehicle starting, low speed, and certain gear shifting conditions). In torque converter mode, lock-up clutch 136 is disengaged, and pump 110 rotates at the speed of drive unit output shaft 104, while turbine 112 is rotatably actuated by pump 110 via fluid (not shown) inserted between pump 110 and turbine 112. In this operating mode, torque multiplication occurs due to the flowable connection, exposing turbine shaft 114 to drive a torque greater than that supplied by drive unit 102, as is known in the art. Torque converter 108 can alternatively operate in a so-called "lock-up" mode under other operating conditions (such as when torque multiplication is not required). In the lock-up mode, the lock-up clutch 136 engages and the pump 110 is thereby directly fastened to the turbine 112, so that the drive unit output shaft 104 is directly connected to the input shaft 124 of the transmission 118, as is also known in the art.

[0043] The transmission 118 further includes an electro-hydraulic system 138, which has J fluid paths 1401-140 J It is circumferentially connected to the planetary gear train 122, where J can be any positive integer. The electro-hydraulic system 138 responds to a control signal to selectively direct fluid flow through fluid paths 1401-140. JOne or more of these components control the operation (i.e., engagement and disengagement) of a plurality of corresponding friction devices in the planetary gear system 122. These friction devices may include, but are not limited to, one or more conventional braking devices, one or more torque transmission devices, etc. Typically, the operation (i.e., engagement and disengagement) of the plurality of friction devices is controlled by selectively controlling the friction exerted by each of the plurality of friction devices, such as by controlling the fluid pressure to each of the friction devices. In one example embodiment, not intended to be limiting, the plurality of friction devices includes a plurality of brakes and torque transmission devices in the form of conventional clutches, each controllably engaged and disengaged by fluid pressure supplied by the electro-hydraulic system 138. In any case, the change or shifting between the various gears of the transmission 118 is achieved by selectively controlling the plurality of friction devices (through many fluid paths 1401-140...) J The control of internal fluid pressure is achieved in a conventional manner.

[0044] System 100 further includes a transmission control circuit 142 that may include a memory unit 144. The transmission control circuit 142 is illustratively microprocessor-based, and the memory unit 144 typically includes instructions stored therein that can be executed by a processor of the transmission control circuit 142 to control the operation of the torque converter 108 and the transmission 118, i.e., shifting between the various gears of the planetary gear train 122. However, it should be understood that this disclosure contemplates other embodiments in which the transmission control circuit 142 is not microprocessor-based, but is configured to control the operation of the torque converter 108 and / or the transmission 118 based on one or more sets of hard-wired instructions and / or software instructions stored in the memory unit 144.

[0045] exist Figure 1 In the illustrated system 100, the torque converter 108 and transmission 118 include a plurality of sensors configured to generate sensor signals that respectively indicate one or more operating states of the torque converter 108 and transmission 118. For example, the torque converter 108 illustratively includes a conventional speed sensor 146 positioned and configured to generate a speed signal corresponding to the rotational speed of the pump shaft 106, which is the same as the rotational speed of the output shaft 104 of the drive unit 102. The speed sensor 146 is electrically connected via signal path 152 to the pump speed input PS of the transmission control circuit 142, and the transmission control circuit 142 is operable to process the speed signal generated by the speed sensor 146 in a conventional manner to determine the rotational speed of the pump shaft 106 / drive unit output shaft 104.

[0046] The transmission 118 illustratively includes another conventional speed sensor 148, which is positioned and configured to generate a speed signal corresponding to the rotational speed of the transmission input shaft 124, the same rotational speed as the turbine shaft 114. The input shaft 124 of the transmission 118 is directly coupled to or integrated with the turbine shaft 114, and the speed sensor 148 is alternatively positioned and configured to generate a speed signal corresponding to the rotational speed of the turbine shaft 114. In either case, the speed sensor 148 is electrically connected via signal path 154 to the transmission input shaft speed input terminal TIS of the transmission control circuit 142, and the transmission control circuit 142 is operable to process the speed signal generated by the speed sensor 148 in a conventional manner to determine the rotational speed of the turbine shaft 114 / transmission input shaft 124.

[0047] The transmission 118 further includes another speed sensor 150, which is positioned and configured to generate a speed signal corresponding to the rotational speed of the output shaft 126 of the transmission 118. The speed sensor 150 may be conventional and is electrically connected via signal path 156 to the transmission output shaft speed input terminal TOS of the transmission control circuit 142. The transmission control circuit 142 is configured to process the speed signal generated by the speed sensor 150 in a conventional manner to determine the rotational speed of the transmission output shaft 126.

[0048] In an illustrative embodiment, the transmission 118 further includes one or more actuators configured to control various operations within the transmission 118. For example, the electro-hydraulic system 138 illustratively described herein includes a plurality of actuators, such as conventional solenoid valves or other conventional actuators, which are transmitted via a corresponding number of signal paths 721-72. J The number of J control output terminals CP1-CP connected to the transmission control circuit 142 is J. J , where J can be any positive integer as described above. Each actuator within the electro-hydraulic system 138 responds in one of its corresponding signal paths 721-72. J One of the corresponding control signals CP1-CP generated by the transmission control circuit 142. J To control the flow in one or more corresponding fluid channels 1401-140 J The pressure of the fluid inside is used to control the friction exerted by each of the multiple friction devices, and thus the operation of one or more corresponding friction devices, i.e., engagement and disengagement, is controlled based on information provided by various speed sensors 146, 148 and / or 150.

[0049] The friction mechanism of the planetary gear train 122 is illustratively controlled by hydraulic fluid distributed in a conventional manner by an electro-hydraulic system. For example, the electro-hydraulic system 138 illustratively includes a conventional hydraulic positive displacement pump 120, which distributes fluid to one or more friction mechanisms under the control of one or more actuators within the electro-hydraulic system 138. In this embodiment, the control signals CP1-CP... J Illustratively, this refers to a simulated friction device pressure command, to which the one or more actuators respond to control the hydraulic pressure of the one or more friction devices. However, it should be understood that friction exerted by each of the plurality of friction devices may alternatively be controlled according to other conventional friction device control structures and techniques, and such other conventional friction device control structures and techniques are contemplated in this disclosure. However, in any case, the simulated operation of each friction device is controlled by control circuitry 142 according to instructions stored in memory unit 144.

[0050] In an illustrative embodiment, system 100 further includes drive unit control circuitry 160 having input / output ports (I / O) electrically connected to the drive unit 102 via a number of K signal paths 162, where K can be any positive integer. Drive unit control circuitry 160 may be conventional and is operable to control and manage the overall operation of drive unit 102. Drive unit control circuitry 160 further includes a communication port COM electrically connected to a similar communication port COM of transmission control circuitry 142 via a number of L signal paths 164, where L can be any positive integer. The one or more signal paths 164 are typically collectively referred to as data links. Typically, drive unit control circuitry 160 and transmission control circuitry 142 are operable to share information in a conventional manner via one or more signal paths 164. For example, in one embodiment, drive unit control circuit 160 and transmission control circuit 142 are operable to share information via one or more signal paths 164 in the form of one or more messages according to the Society of Automotive Engineers (SAE) J-1939 communication protocol. However, this disclosure anticipates other embodiments in which drive unit control circuit 160 and transmission control circuit 142 are operable to share information via one or more signal paths 164 according to one or more other conventional communication protocols (e.g., from conventional data buses such as J1587 data bus, J1939 data bus, IESCAN data bus, GMLAN, Mercedes PT-CAN).

[0051] See Figure 2 It illustrates a hydraulic control system for a multi-stage transmission system 200. The system 200 may include... Figure 1Similar features to the transmission 118. For example, system 200 may include torque converter 202 or other circumferentially coupled means for circumferentially coupling the transmission system 200 to the engine or other drive unit 102. Torque converter 202 may include similar features to Figure 1 The lock-up clutch of clutch 136 (not shown). Additionally, the transmission system 200 may include a main fluid pump 204 for providing hydraulic fluid and pressure throughout the system. Pump 204 may be similar to... Figure 1 An internal pump 120. Here, pump 204 is circumferentially connected to a reservoir 206 or collection tank that supplies fluid to the suction side of pump 204. In this disclosure, pump 204 may be referred to as a fluid or pressure source of system 200.

[0052] The transmission system 200 may include other systems or subsystems, such as a pressure regulator system, a lubrication system, a converter system, and a cooler system. Figure 2 In this transmission system 200, a main regulator 208 may be in fluid communication with pump 204. The main regulator 208 may be a valve or other fluid regulating mechanism for regulating the main pressure in system 200. In this disclosure, all main pressure may be provided to transmission system 200 by pump 204. The main regulator 208 can regulate this pressure and, as described below, can trigger other solenoid valves, etc., to further regulate the main pressure. In any case, the main regulator forms part of a pressure regulator system, and the main pressure flows from the main regulator 208 to the main pressure line 218 of transmission system 200, as described below.

[0053] The main regulator 208 is further flowably coupled to the converter system. The converter system may include a torque converter 202, a converter release device 210, and a converter flow 214. In one example, the converter release device 210 and the converter flow 214 may be valves. Hydraulic fluid may flow from the main regulator 208 to the converter release device 210 and the converter flow 214. Furthermore, fluid may flow from the converter flow 214 to the torque converter 202 through a converter in-transformer passage 222, and fluid may flow from the torque converter 202 to the converter flow 214 through a converter external passage 220. In this way, fluid pressure can flow to and from the torque converter to better regulate the fluid operating temperature in the torque converter 202 and provide cooler fluid to protect the lock-up clutch (if applicable). Other reasons or advantages may exist for flowably coupling the torque converter 202 to the converter flow 214, as may be understood by those skilled in the art.

[0054] The transmission system 200 may also include a lubrication system and a cooler system. The lubrication system may include a lubrication regulator 212 for regulating pressure to cool clutches, brakes, etc., in the system 200. The cooler system may include a cooler 216, such as a vehicle cooler, that can be disposed outside the transmission system 200. However, the cooler 216 may be in fluid communication with the converter flow 214 and the lubrication regulator 212, as in… Figure 2 As shown in the diagram. Cooler 216 may be further configured to provide cooler flow 224 to the lubricating oil line.

[0055] Figure 2 This is just one embodiment of the transmission system. Other components or systems may exist, forming a connection with... Figure 2 The embodiments shown are a subset of different embodiments. The teachings of this disclosure are not intended to be limited to any particular embodiment.

[0056] This disclosure provides an electro-hydraulic control system for controlling a multi-stage transmission. The multi-stage transmission may include multiple forward and reverse gear ratios. Furthermore, the multi-stage transmission may include an input end, an output end, multiple planetary gear sets, and multiple torque transmission mechanisms that can selectively engage to achieve multiple forward and reverse gear ratios. In one example, the multi-stage transmission may be a nine-stage transmission having an input end, an output end, a first planetary gear set, a second planetary gear set, a third planetary gear set, and a fourth planetary gear set. Each planetary gear set may be disposed between the input end and the output end, and each planetary gear set may include a sun gear, a ring gear, and a carrier component. Additionally, in this example, the transmission may include multiple interconnecting components for interconnecting and connecting the planetary gear sets and torque transmission mechanisms to the input end and the output end. A non-limiting example of a multi-stage transmission architecture controllable by the teachings of this disclosure is disclosed in U.S. Patent No. 7,364,527, issued April 29, 2008, and assigned to General Motors Corporation, the disclosure of which is incorporated herein by reference.

[0057] See Figure 3-17 It illustrates an electro-hydraulic control system 300 for a multi-stage transmission with multiple ranges including at least one neutral gear and one reverse gear range. The electro-hydraulic control system 300 can be used with... Figure 1 The electro-hydraulic system 138 is similarly positioned. Specifically, the electro-hydraulic control system 300 can be used with, for example... Figure 1 The controller of the transmission control circuit 142 shown is electrically connected. Furthermore, the electro-hydraulic control system 300 may include a means for fluidly connecting to the planetary gear train 122 (such as...). Figure 1 Multiple fluid paths (e.g., fluid paths 1401-140) of the planetary gear system shown. jIn other embodiments, the control system 300 may be electrically or circumferentially connected to other systems or subsystems of the multi-stage transmission system.

[0058] The electro-hydraulic control system 300 may include multiple valves and solenoid valves for controlling the selective engagement of one or more clutches or brakes. For the purposes of this disclosure, each clutch or brake may be referred to as a torque transmission mechanism. Furthermore, and as will be described below, the system 300 may include a pressure switch for detecting pressure within a line or fluid path in the system 300. Other mechanisms will be described in this disclosure. Notably, Figure 3-17 Only one embodiment of an electro-hydraulic control system for a multi-stage transmission is shown. However, this disclosure is not intended to be limited to this embodiment alone.

[0059] Specifically, turn to Figure 3 The 300 electro-hydraulic control system can be integrated with... Figure 2 The transmission system 200 is fluidly connected. Specifically, the fluid source 302 to the control system 300 is fluidly connected to the pump 204 via the main regulator 208 and the main pressure line 218. Hydraulic fluid can be supplied from the pump 204 to the control system 300 and is regulated by the main regulator 208. Thus, the fluid from the pressure source 302 can be referred to as the main pressure. Various fluid pressures and fluid lines in the electro-hydraulic control system 300 are identified in this disclosure. Figure 23 As shown in the illustrations, these fluid pressures include the main pressure, control main pressure, vent backfill pressure, vent pressure, main modulation pressure, torque converter lock-up clutch signal pressure, torque converter lock-up clutch pressure, pressure control solenoid valve signal pressure, and clutch pressure. In other embodiments, additional or fewer signal pressures or fluid pressures may be present in the control system, and the illustrative embodiments of this disclosure are not intended to limit in this way.

[0060] See Figure 3 The electro-hydraulic control system 300 may include multiple fine-tuning systems, each of which includes a solenoid valve and a fine-tuning valve. For example, a first fine-tuning system may include a torque converter clutch fine-tuning solenoid valve 304 (i.e., a TCC solenoid valve) and a torque converter clutch fine-tuning valve 306. An accumulator (not labeled) adjacent to the TCC fine-tuning solenoid valve 304 is also shown. Figure 3 (Left side of solenoid valve 304). Activation of the TCC fine-tuning system provides hydraulic fluid through the TCC flow path to converter flow 214. Fluid can flow from converter flow 214 to apply force to the lock-up clutch of torque converter 202 through the converter in flow path 222. This is best illustrated in Figure 2 and 6 middle.

[0061] Figure 3-17 Each of the fine-tuning systems depicted includes an accumulator, but in other embodiments, not every fine-tuning system includes an accumulator. The accumulator is a small valve that travels according to the output pressure of the solenoid valve. When it travels or does not travel, a large amount of fluid from the solenoid valve output flows back through the solenoid valve. The accumulator can be any conventional mechanism used to provide a more stable control system.

[0062] The second fine-tuning system includes a first pressure-controlled solenoid valve 308 and a first pressure-controlled fine-tuning valve 310. The fine-tuning system may include, for example: Figure 3 The accumulator shown is an example. The first pressure control solenoid valve 308 may be referred to as a constant high pressure control solenoid valve. For the purposes of this disclosure, when no current is supplied to the solenoid valve, the constant high pressure control solenoid valve outputs full pressure. In other words, if the power is cut off or the power supply is disconnected from the first pressure control solenoid valve 308, its default position is to output full pressure to advance the first pressure control fine-tuning valve 310.

[0063] As also shown, hydraulic fluid can flow through the second fine-tuning system to apply force to the first torque transmission mechanism C1. C1 can be a clutch or a brake. Figure 3 In this case, C1 is not under stress, and hydraulic fluid is discharged for backfilling, as shown. Discharge backfilling and discharge may simply refer to the release or return of hydraulic fluid to reservoir 206.

[0064] Figure 3 Another fine-tuning system includes a second pressure-controlled solenoid valve 312 and a second pressure-controlled fine-tuning valve 314. Similar to the first pressure-controlled solenoid valve 308, the second pressure-controlled solenoid valve 312 can be a constant-high-pressure control solenoid valve. Therefore, if power is lost or the power supply is disconnected from the second pressure-controlled solenoid valve 312, it defaults to full output pressure to allow the second pressure-controlled fine-tuning valve 314 to proceed.

[0065] Another fine-tuning system in the control system 300 includes a third pressure control solenoid valve 316 and a third pressure control fine-tuning valve 318. Similar to the first and second fine-tuning solenoid valves, the third pressure control solenoid valve 316 can be a constant high-pressure control solenoid valve. Therefore, if power is lost or the power supply is disconnected from the third pressure control solenoid valve 316, it defaults to full output pressure to allow the third pressure control fine-tuning valve 318 to proceed. Furthermore, when the third pressure control fine-tuning valve 318 is in motion, hydraulic fluid can flow and apply force to the third torque transmission mechanism C3. Similar to C1, C3 can be a clutch or brake.

[0066] The electro-hydraulic control system 300 further includes a fine-tuning system formed by a fourth pressure control solenoid valve 320 and a fourth pressure control fine-tuning valve 322. The fourth pressure control solenoid valve 320 may be a normally low pressure control solenoid valve. Therefore, unlike a normally high pressure control solenoid valve, the normally low pressure control solenoid valve generates zero output pressure when no current is supplied to the solenoid valve. If the fourth pressure control solenoid valve 320 is actuated or energized by the transmission controller or control circuit and is de-energized, the fourth pressure control solenoid valve 320 defaults to zero output pressure and the fourth pressure control fine-tuning valve 322 does not move.

[0067] This fine-tuning system can also control the fluid pressure to the fourth torque transmission mechanism C4. C4 can be a clutch or brake. When the fourth pressure control fine-tuning valve 322, or only the fourth fine-tuning valve, is moved to its traveling position, fluid pressure can fill and apply force to C4. However, when de-energized, the fourth pressure control solenoid valve 320 is de-energized, and the fourth fine-tuning valve 322 is not traveling, thus preventing the hydraulic fluid from applying force to C4. This will be described further below.

[0068] Another fine-tuning system in the control system 300 includes a fifth pressure control solenoid valve 324 and a fifth pressure control fine-tuning valve 326. In this embodiment, the fifth pressure control solenoid valve 324 is another normally low-pressure control solenoid valve, which defaults to zero output pressure when current is no longer supplied to the solenoid valve. Therefore, when power is off, the fifth pressure control fine-tuning valve 326, or simply put, the fifth fine-tuning valve 326, does not move.

[0069] like Figure 3 As shown, the fifth pressure control solenoid valve 324 and the fifth fine-tuning valve 326 control the hydraulic fluid to apply force to the sixth torque transmission mechanism C6. C6 can be a clutch or brake. When the fifth fine-tuning valve 326 is in motion, fluid can fill and apply force to C6. When the valve is not in motion, no force can be applied to C6. Another feature of this fine-tuning system is the inclusion of a pressure-boosting plug 328. The pressure-boosting plug 328 may include a hollow opening or channel 344 defined therein for fluid to pass through the plug 328 and move the fifth fine-tuning valve 326. As will be described below, the pressure-boosting plug 328 allows different gains to be achieved by means of this fine-tuning system.

[0070] The control system 300 may further include a second torque transmission mechanism C2 and a fifth torque transmission mechanism C5. C2 and C5 may be clutches or brakes. Hydraulic fluid for applying force to C2 or C5 may flow through a fluid passage defined by the relative position of the second fine-tuning valve 314.

[0071] Figure 3The electro-hydraulic control system 300 further illustrates a pair of on-off shift solenoid valves 330, 332. Each solenoid valve can be energized or de-energized by a controller (e.g., a transmission controller or transmission control circuit 142). When the solenoid valve is energized, i.e., it is considered "open", the solenoid valve is able to output control pressure. When the solenoid valve is de-energized, i.e., it is referred to as "closed", the solenoid valve does not output any control pressure.

[0072] In this disclosure, the control pressure is the pressure fed from the main pressure line 218 or pressure source 302, but it is regulated at a maximum pressure typically below the main pressure. Furthermore, the control pressure, i.e., the "control main pressure," is referred to as the feed pressure to all actuators. The control pressure may be regulated, for example, at 110 psi. This is just one example, as the control pressure may be regulated at different pressures for other embodiments. In contrast, the main pressure may exceed the control pressure based on specific torque requirements of the transmission. For example, in one embodiment, the main pressure may vary between 50 psi and 250 psi, while the control pressure may be limited to the regulated pressure (e.g., 110 psi).

[0073] The solenoid valves in the control system 300 can be controlled using control pressure, such that the maximum output pressure of the solenoid valves is the control pressure. To achieve the control pressure, a main pressure is supplied from pressure source 302 to control main valve 334. The hydraulic fluid flowing out of control main valve 334 is the control pressure, which then flows through control main filter 336 to remove any debris or unwanted particles from the fluid. The control pressure then flows to each of the aforementioned pressure control solenoid valves and on / off solenoid valves. The control pressure can also be fed in via different actuators or shift valves, which will be described below. Furthermore, the control pressure pressurizes the pressure switches in the control system 300.

[0074] Another mechanism used to reduce or further regulate the main pressure is the main modulation solenoid valve 340. The main modulation solenoid valve 340 outputs a reduced main pressure and can be energized and de-energized by a controller. Although Figure 3 Not shown, but the modulated main pressure from the main modulating solenoid valve 340 can flow to Figure 2 The main regulator 208 in the middle increases or decreases the main pressure based on the output of the solenoid valve.

[0075] The control system 300 includes several different valves, including a discharge backfill pressure reducing valve 338 and a discharge backfill valve 342. In each case, fluid pressurized by either valve can be discharged into the reservoir 206. Another type of valve in the control system 300 is a check valve 352. Figure 3In this embodiment, several check valves 352 are present in various paths to restrict or prevent flow in a certain direction of the flow path. The check valves 352 may be any conventional check valve used for the purposes of this disclosure.

[0076] The control system 300 further includes multiple shift valves or actuators. The shift valves may function differently from the fine-tuning valves. For example, the aforementioned fine-tuning valve can be used to modulate pressure to a desired clutch pressure. Here, the main pressure can be fine-tuned to the required clutch or fine-tuning pressure. On the other hand, the shift valve changes or redirects hydraulic fluid from one flow path to a different flow path.

[0077] exist Figure 3-17 In the illustrative embodiment, the control system 300 may include a first shift valve 346, a second shift valve 348, and a third shift valve 350. The function of each shift valve, particularly its range and fault range, will be described below. However, the second shift valve 348 may directly feed clutch pressure to the second torque transmission mechanism C2 and the fifth torque transmission mechanism C5. In this control system 300, for a given range, only one of C2 and C5 is subjected to force.

[0078] Each of the shift valves is movable between a moving position and a non-moving position. To do this, a first shift solenoid valve 330 may be configured to actuate the first and second shift valves, and a second shift solenoid valve 332 may be configured to actuate the third shift valve 350. The manner in which each shift valve is actuated within a given range will be further described below.

[0079] exist Figure 3 Another valve shown in the control system 300 includes a booster valve 354. The booster valve 354 and the second fine-tuning valve 314 control the hydraulic fluid to C2 and C5, which will be described below.

[0080] The control system 300 further includes a first pressure switch 356, a second pressure switch 358, a third pressure switch 360, and a fourth pressure switch 362. Each pressure switch is actuated between a first position and a second position. In the first position, pressure is applied to the pressure switch, and in the second position, no pressure is applied to the pressure switch. Based on the positions, the controller can detect the positions and gains of different valves throughout the control system 300.

[0081] In this disclosure, the control system 300 is configured to apply force to two torque transmission mechanisms. For example, see [link to relevant documentation]. Figure 21 The document provides a mechanized table 2100 for a multi-stage transmission. This table 2100 shows multiple forward gear ranges, neutral gear ranges, and reverse gear ranges. In this embodiment, there are nine forward gear ranges, but in other embodiments, different numbers of forward and reverse gear ranges may exist. This disclosure is not limited to any number of forward and reverse gear ranges.

[0082] Figure 21 The columns of Table 2100 further illustrate the different solenoid valves. As shown, shift solenoid valves 330 and 332 are shown as normally low solenoid valves (“N / L”), and fourth pressure control solenoid valve 320 and fifth pressure control solenoid valve 324. First pressure control solenoid valve 308, second pressure control solenoid valve 312, and third pressure control solenoid valve 316 are shown as normally high solenoid valves (“N / L”) in Table 2100. In the table, zero (“0”) identifies the solenoid valve as closed or not receiving current, while one (“1”) indicates the solenoid valve as open or receiving current (i.e., energized). The pressure control solenoid valves indicate which clutch can be forceped in each range. The following table illustrates one embodiment of engagement or force applied to at least two torque transmission mechanisms:

[0083]

[0084] However, Mechanization Table 2100 describes other clutches that can be used for any given range. For example, in the fifth range, forces are applied to C1 and C3 to achieve this range. However, C4 and C6 are also available if the necessary fine-tuning system is triggered to allow fluid flow to the corresponding clutches. For example, if the fifth pressure control solenoid valve 324 is energized in the fifth range, the fifth fine-tuning valve 326 can be moved to allow pressure filling and apply force to C6. Thus, Mechanization Table 2100 describes the clutches under force, and the clutches that can be available depending on the valve position or the state of the solenoid valve. This is further described below regarding the hydraulic default range.

[0085] exist Figure 21 In the mechanized table 2100, it is worth noting that the first pressure control solenoid valve 308 can control C1 between a stressed and unstressed state, the second pressure control solenoid valve 312 can control C2 or C5 between a stressed and unstressed state, as discussed above, and the third pressure control solenoid valve 316 can control C3 between a stressed and unstressed state. Each of these three solenoid valves is a constant-pressure solenoid valve, and therefore, if power is cut off or no current is sent to these solenoid valves, each solenoid valve still outputs full pressure to the corresponding fine-tuning valve. If hydraulic pressure is received at the corresponding fine-tuning valve, force can be applied to the corresponding clutch or brake (C1, C2 / C5, and C3) through the solenoid valve that outputs full pressure.

[0086] Furthermore, Table 2100 further illustrates that the fourth pressure control solenoid valve 320 can control C4 between a stressed and unstressed state, and the fifth pressure control solenoid valve 324 can control C6 between a stressed and unstressed state. However, both of these solenoid valves are normally low solenoid valves, and therefore output zero pressure when the solenoid valves do not receive current. In this embodiment, if power is de-energized and force is applied to C4 or C6, the corresponding pressure control solenoid valve stops sending pressure to the corresponding fine-tuning valve and does not apply force to the clutch or brake. Therefore, regarding C4 and C6, if power is de-energized and no current is sent to their respective pressure control solenoid valves, both torque transmission mechanisms can be triggered from their stressed state to their unstressed state.

[0087] exist Figure 21 The mechanization table 2100 further illustrates the different hydraulic default ranges for each of the forward, neutral, and reverse gear ranges. Figure 3 In the control system 300 and the multi-stage transmission controlled by the control system 300, in addition to neutral, there are combinations of two clutches or brakes that are stressed in each range. In neutral, only one clutch or brake is stressed. However, Table 2100 identifies other clutches or brakes that can be stressed. For example, in the first range, C5 and C6 are normally stressed. However, the table further shows that torque transmission mechanisms C1, C3, and C4 can be stressed if the controller operably energizes or de-energizes the necessary solenoid valves. The same applies to other ranges, such as the eighth range, in which C2 and C4 are stressed, but C3 and C6 are available if the controller energizes the third and fifth pressure control solenoid valves.

[0088] As shown in the table, the control system 300 includes a neutral default range, a low default range (i.e., the fifth range), and a high default range (i.e., the seventh range). In neutral, the control system 300 can be optimally configured such that if power is lost, no force is applied to C5 and force is applied to C3 to achieve the C3N default range (i.e., C3 neutral). As discussed above, C3 is controlled by a third pressure control solenoid valve 316, and when power is lost, the third pressure control solenoid valve 316 still outputs full pressure to advance the third fine-tuning valve 318, and allows hydraulic pressure to fill at the fine-tuning valve and apply force to C3. This will refer to Figure 15-17 Further explanation. See below for more details. Figure 15-17 To illustrate how the low and high default ranges are achieved. However, for the purposes of this disclosure, the control system 300 is capable of defaulting to three different conditions or ranges in the event of a power failure, and each condition or range is designed to better protect the transmission from damage.

[0089] exist Figure 3-17 The control diagram does not show the fine-tuning valve and shift valve in further detail; that is, there is no further detail regarding their length and diameter. See also Figure 18 This illustrates a non-limiting example of valve 1800. In this example, valve 1800 may be an example of a first shift valve 346. Here, the overall length of valve 1800 has different portions and diameters (or widths). Valve 1800 may include a stem or body 1802. Furthermore, along the length of valve 1800, there are a first valve portion 1804, a second valve portion 1806, a third valve portion 1808, a fourth valve portion 1810, a fifth valve portion 1812, and a sixth valve portion 1814. In this example, the diameter of the fourth valve portion 1810 is D1, which is larger than the diameters of the first, second, and third portions. Additionally, the diameter D2 of the fifth valve portion 1812 is larger than D1, and therefore, the diameter of the fifth valve portion 1812 is larger than the diameters of the first, second, third, and fourth valve portions. Furthermore, the overall diameter D3 of the sixth valve portion 1814 is larger than both diameters D1 and D2. Thus, the sixth valve portion D3 is the largest diameter of valve 1800.

[0090] exist Figure 18 The valve 1800 is also shown as having three interlocked or latched positions. Interlocking or latching refers to hydraulically holding the valve in place, regardless of solenoid valve pressure. Therefore, the valve cannot move as long as hydraulic pressure is available at the interlocked or latched position. This is particularly relevant to shift valves. Although not shown in this disclosure, each shift valve may be disposed within a valve sleeve, such as a valve body, along with a return spring. The spring may have a spring force to counteract the movement of the shift valve from its non-moving position to its moving position. However, by latching or interlocking, sufficient hydraulic pressure can be applied to the valve portion to hold the valve in place, even if the solenoid valve pressure at the valve head is removed. Figure 18 The diagram shows a first interlock 1816 on the fourth valve section 1810, a second interlock 1818 on the fifth valve section 1812, and a third interlock 1820 on the sixth valve section 1814. Therefore, three interlocks can exist on the first shift valve 346.

[0091] Regarding the interlock, the first shift valve can be referred to as a range valve. During operation, hydraulic fluid acting on one of these interlocks allows the range valve to remain within a certain range. The same applies to neutral. Furthermore, the interlock on the first shift valve allows the control system to default to the necessary default range, such as in... Figure 21 As shown in the image.

[0092] The interlock is based on force balance along the valve. If hydraulic pressure is acting on the first interlock 1816, and more specifically, on diameter D1, this pressure can be greater than the spring force that counteracts the hydraulic pressure. This force can be determined in a conventional manner, i.e., the amount of pressure multiplied by the area of ​​the valve portion. Regarding the first shift valve 346, the interlock can be based on which torque transmission mechanism is engaged to hold the valve in its traveling position. In the fifth range, for example, there may be no control pressure from the first shift solenoid valve, which in some cases would prevent the first shift valve 346 from traveling. However, the hydraulic pressure acting on the third interlock 1820 can maintain the valve in its traveling state and allow the clutch pressure to fill and apply force to C1. This is just one of several examples of interlocks holding the shift valve in the desired position for a specific range. In another example, force is applied to C2, and hydraulic pressure flows to the first shift valve 346 and can act on the second interlock 1818 to hold the valve in its traveling position.

[0093] See Figure 19 This illustrates an example of a second shift valve 348. Here, the valve 1900 representing the second shift valve 348 may include a length defined by a valve stem or body 1902, a first valve portion 1904, a second valve portion 1906, a third valve portion 1908, a fourth valve portion 1910, a fifth valve portion 1912, and a sixth valve portion 1914. (As shown in...) Figure 19 As shown, the first, second, and third valve portions may include a diameter D4, while the fourth, fifth, and sixth valve portions may include a diameter D5. Here, D5 is larger than D4, thereby forming or defining an interlock 1916 on the larger valve portion. Furthermore, a second interlock 1918 is located at one end of valve 1900. The second interlock 1918 can maintain the second shift valve 348 in the non-moving position by the clutch pressure for C5. Therefore, even if control pressure is provided at the opposite end of the second shift valve 348 via the first shift solenoid valve 330, the hydraulic pressure at the second interlock 1918 is sufficient to keep the valve from moving.

[0094] Regarding the first interlock 1916 on valve 1900, this can be useful when operating in a higher range (e.g., ranges six through nine) and applies force to C2. As previously noted, the second shift valve 348 can specify whether force is applied to C2 or C5. In other words, this shift valve is multiplexed, which will be described below. However, in the seventh range ( Figure 12In this configuration, the first shift solenoid valve 330 can supply control pressure to one end of the second shift valve 348 to move it to its travel position. Hydraulic pressure filling and applying force to C2 can also flow between the third valve section 1908 and the fourth valve section 1910, and the second shift valve 348 can be hydraulically held in place due to the first interlock 1916, regardless of whether the first shift solenoid valve 330 sends control pressure. This is again due to the hydraulic pressure acting on the differential region of valve 1900 (due to force balance across the valve). Therefore, the interlock can be used to establish a default range ( Figure 15-17 This will be discussed further below.

[0095] As mentioned above, the second shift valve 348 can be multiplexed. However, firstly, in Figure 3 In the control system 300, each clutch or brake hydraulically fills and applies force to something. For C1, C3, C4, and C6, there are fine-tuning systems for filling and applying force to each torque transmission mechanism; in a multiplexed system, a single fine-tuning system is used to hydraulically apply force to more than one torque transmission mechanism. Regarding C2 and C5, a second shift valve 348, a second pressure control solenoid valve 312, a second fine-tuning valve 314, and a booster valve 354 can be used for hydraulic control. In one example, if the second shift valve 348 is not in motion (i.e., moving upwards), C5 (i.e., reverse, neutral, and the first and second ranges) can be hydraulically controlled. On the other hand, if the second shift valve 348 is in motion (i.e., moving downwards), C2 (i.e., the sixth to ninth ranges) can be hydraulically controlled. Therefore, if hydraulic pressure is available at the second shift valve, force can be applied to C2 or C5 based on the position of the shift valve.

[0096] When the second shift valve 348 acts as a multiplexing system, less hardware (such as fine-tuning solenoids and fine-tuning valves) is necessary for the control system. Furthermore, the multiplexing system effectively "locks in" or prevents both C2 and C5 from being stressed simultaneously. This can be important, for example, to protect the integrity of the transmission from potential damage due to locked-in output. At higher speeds when force is applied to C2, if force is applied to C5 simultaneously, there is a potential for damage to the transmission. Therefore, the second shift valve 348 can allow only C2 or C5 to be hydraulically stressed, and not the other.

[0097] See now Figure 20 This illustrates a representative valve 2000 used for the third shift valve 350. Valve 2000 is only one example of the third shift valve 350, as it may differ in other examples. However, in Figure 20In this embodiment, valve 2000 may include a length defined by valve stem or body 2002, a first valve portion 2004, a second valve portion 2006, a third valve 2008, a fourth valve portion 2010, and a fifth valve portion 2012. In this example, each valve portion has the same diameter or width. Therefore, there is no interlock or latch formed with this valve 2000. However, in other embodiments, one or more of the valve portions may have different diameters or widths to form an interlock or latch.

[0098] In this disclosure, the third shift valve 350 may be referred to as a power valve. The power valve is capable of blocking hydraulic pressure from exerting force on C1. It effectively blocks the main pressure feed to the first pressure control fine-tuning system (e.g., the first fine-tuning valve 310). In the seventh scope, for example, the third shift valve 350 is capable of blocking the main pressure from reaching the first fine-tuning valve 310 ( Figure 12 ).exist Figure 12 In this configuration, the primary pressure is supplied by pressure source 302, and it flows to the third shift valve 350. As noted above, the third shift valve 350 may not include any interlocks or latches, and therefore its position can be controlled by control pressure from the second shift solenoid valve 332. However, in Figure 12 In this configuration, the second shift solenoid valve 332 can be de-energized, preventing it from outputting any control pressure. Without any control pressure acting on the third shift valve 350, the third shift valve 350 remains stationary. In its stationary position, the main pressure from pressure source 302 is blocked (e.g., through the second valve section 2006). Therefore, from... Figure 12 Furthermore, in the seventh range, because the third shift valve 350 blocks the pressure from reaching the first fine-tuning valve 310, no force is applied to C1. The same applies in the eighth and ninth ranges.

[0099] The third shift valve 350 can also block hydraulic fluid flow to the second fine-tuning system, namely, the second fine-tuning valve 314. Furthermore, the third shift valve 350 effectively blocks flow to the second shift valve 348. However, in the seventh range, for example, the interlock on the second shift valve 348 maintains the valve in the filled position, applying force to C2. As discussed below, the second shift valve 348 and the third shift valve 350 can also be controlled so that hydraulic pressure is not fed into all three fine-tuning valves actuated by the constant-high solenoid valve. If clutch pressure is fed into all three fine-tuning valves, one of C1, C3, and C2 or C5 will apply, potentially damaging the transmission. The control system 300 therefore controls the position and movement of the second and third shift valves to block flow from one or more of the fine-tuning valves to prevent damage to the transmission.

[0100] Another feature of this disclosure is the control range valve, namely, the first shift valve 346. The range valve is operably controllable by the shift-by-wire control system. In other words, the vehicle operator can press a button, turn a knob, trigger a switch, or perform some other operation to send a command to the controller to select a range for the transmission system. The controller can then energize one or more solenoid valves to electrically actuate the control system 300 to the desired range. Therefore, in the shift-by-wire control system, there is no manual linkage for controlling the pawl, or anything similar for manually controlling the transmission system to a certain range. In this disclosure, the controller can therefore control the position of the range valve (i.e., the first shift valve 346) to select a range or shift to a different range.

[0101] In an alternative embodiment, the range valve can be replaced by a three-position manual valve that is manually actuated via a shift linkage. In other words, a cable or other linkage can be installed for manual control of the transmission to the appropriate range.

[0102] Now transferred to Figure 3 The specific details show the control system 300 operating in reverse gear. In other words, the controller has received a command from the operator to control the transmission in reverse gear via the shift-by-wire system, or the operator has controlled the shift lever to control the transmission in reverse gear. In any case, the main pressure is supplied to the control system 300 by pressure source 302. As in... Figure 21 As shown and described above, C3 and C5 are engaged in reverse gear. To achieve this, the main pressure is fed into the third fine-tuning valve 318, and the controller energizes the third pressure control solenoid valve 316 to move the third fine-tuning valve 318 to its traveling position. In this way, hydraulic fluid can be filled in reverse gear and apply force to C3.

[0103] For C5, it is important to note that the first shift solenoid valve 330 is de-energized, and the second shift solenoid valve 332 is energized. Therefore, the first and second shift valves are in their respective non-moving positions, and the third shift valve 350 is in its moving position (i.e., because the second shift solenoid valve 332 controls the third shift valve 350). Through the third shift valve 350 in its moving position, the main pressure can flow through the third shift valve 350 and through the second shift valve 348, as in... Figure 3 As shown in the diagram, the main pressure flows through the second shift valve 348, which then flows directly to the second fine-tuning valve 314. The controller can energize the second pressure control solenoid valve 312 to move the second fine-tuning valve 314 to its travel position, and with the main pressure at the second fine-tuning valve 314, hydraulic fluid can flow through the second fine-tuning valve 314 and return to flow through the second shift valve 348 to fill and apply force to C5.

[0104] Once C5 is subjected to force, the pressure of C5 flows back through the second shift valve 348, as in... Figure 3As shown in the diagram. Specifically, C5 pressure can flow and apply pressure against one end of the second shift valve 348 to maintain the valve in its position. In this example, an interlock may be formed on one end of the second shift valve 348.

[0105] The C5 pressure also flows back to the booster valve 354, and can force or maintain the booster valve 354 in its non-advanced position. The function and application of the booster valve will be further described below.

[0106] In reverse gear, the other torque transmission mechanisms are not under stress. First, the main pressure flows to the first shift valve 346, but is effectively blocked by the non-moving first shift valve 346. The second shift valve 348 also blocks the main pressure through one of its valve sections. As a result, there is no main pressure fed into the first trimmer valve 310. Regarding C2, as we previously described, the second shift valve 348 is multiplexed and only allows force to be applied to one of C2 or C5. In reverse gear, the second shift valve 348 can be in its non-moving position, such that only C5 is subjected to force.

[0107] Regarding C4 and C6, the controller does not send any current to the fourth pressure control solenoid valve 320 or the fifth pressure control solenoid valve 324, and therefore the corresponding fine-tuning valves do not move. Regarding the fourth fine-tuning valve 322, it... Figure 3 As shown, the main pressure flows to the fourth fine-tuning valve 322. However, since the fourth fine-tuning valve 322 is not in motion, the main pressure is blocked by the fine-tuning valve and cannot fill or apply force to C4. Furthermore, the second shift valve 348 blocks the main pressure feed into the fifth fine-tuning valve 326, and if even pressure were to be fed into the fifth fine-tuning valve 326, it would de-energize the fifth pressure control solenoid valve 324. Therefore, the fifth fine-tuning valve 326 is not in motion, and no hydraulic fluid can fill and apply force to C6.

[0108] Based on the above description and in Figure 3 The reverse gear shown in the diagram allows the control system 300 to further control the transmission from reverse to neutral in the event of a system power failure. This is shown in... Figure 15 In this embodiment, C3 remains under pressure, and C5 is released. During the power-off period, the normally low pressure solenoid valves (i.e., the fourth pressure control solenoid valve 320 and the fifth pressure control solenoid valve 324) are de-energized, and therefore C4 and C6 cannot be filled or under pressure. Furthermore, the first shift solenoid valve 330 and the second shift solenoid valve 332 are de-energized, and therefore the first shift valve 346, the second shift valve 348, and the third shift valve 350 do not move. Finally, the normally high pressure control solenoid valves 308, 312, and 316 output full pressure during the power-off period.

[0109] As in Figure 15As shown, the main pressure is supplied from fluid source 302 to the third fine-tuning valve 318, the fourth fine-tuning valve 322, the first shift valve 346, and the third shift valve 350. Full pressure is output to the third fine-tuning valve 318 via the third pressure control solenoid valve 316, allowing hydraulic fluid to continue filling and applying force to C3. Therefore, from reverse to the default neutral, C3 remains under force. C4 and C6 remain unforced because they are normally low solenoid valves. Even when the first and second pressure control solenoid valves are outputting full pressure to advance the first fine-tuning valve 310 and the second fine-tuning valve 314, the first shift valve 346 and the third shift valve 350 remain unadvanced, effectively blocking the main pressure flow to either fine-tuning valve. Furthermore, due to the unadvanced first and third shift valves, there is no hydraulic fluid for feeding into the second shift valve 348. Without any fluid flowing through either the shift valves or the second fine-tuning valve 314, C2 and C5 are neither filled nor under force. Therefore, in Figure 15 During the power outage event, only C3 is subjected to force and the transmission defaults to C3 neutral.

[0110] During the de-energization process from reverse to neutral (C3), C5 is vented. In one embodiment, C5 can be considered a large clutch or brake that requires a large amount of fluid to apply force. At low temperatures, the viscosity of the fluid prevents it from being rapidly vented from C5. The first venting path for C5 is through the second shift valve 348, and the second venting path is through the second trim valve 314. In both cases, the fluid travels a considerable distance to reach the vent outlet (in...). Figure 3-17 It is identified as an X surrounded by a small circle. Due to its high viscosity at low temperatures, it may be difficult to quickly exhaust C5 through the first or second emission path.

[0111] However, as in Figure 15 As shown, a third and shorter discharge path can be provided for faster venting of C5. Here, a third discharge path is defined from C5 through the third shift valve 350 and to the discharge backfill valve 342 (where the fluid is discharged into the reservoir 206). When C5 is released, the hydraulic fluid can flow through any of these three fluid paths for discharge, and the third discharge path is shorter than the first and second discharge paths, thereby allowing the fluid to be discharged more quickly at a lower temperature.

[0112] See Figure 4This illustrates the control system 300 controlling the transmission in neutral or stationary mode. In this illustrative embodiment, C5 is engaged, and the other torque transmission mechanisms are disengaged. To achieve this setting, the main pressure continues to be supplied by pressure source 302. Here, the controller energizes the second pressure control solenoid valve 312 to move the second fine-tuning valve 314 to its driving position. The other pressure control solenoid valves are de-energized, and thus C1, C3, C4, and C6 are disengaged. The first shift solenoid valve 330 is de-energized, and thus the first shift valve 346 and the second shift valve 348 are not driven. However, the second shift solenoid valve 332 is energized, and the main pressure is controlled to feed into one end of the third shift valve 350 to move it to its driving position.

[0113] The main pressure is fed into the third fine-tuning valve 318 and the fourth fine-tuning valve 322, but there is no pressure filling C3 or C4 through each fine-tuning valve that has not traveled. Figure 4 The first shift valve 346, which has not moved, is primarily pressure-blocked by a portion of the first shift valve 346 (e.g., the third valve portion 1808) to prevent hydraulic fluid from being directed to the first fine-tuning valve 310. Therefore, C1 is not subjected to force for at least this reason (and the first fine-tuning valve 310 is not moving and will further block fluid).

[0114] When the third shift valve 350 is in motion due to the control main pressure fed by the second shift solenoid valve 332, the main pressure can flow through the second shift valve 348, through the third shift valve 350, to the second fine-tuning valve 314. Specifically, when the second shift valve 348 is not in motion, hydraulic fluid may be able to flow between the first portion 1904 and the second portion 1906 of the valve. As fluid flows to the second fine-tuning valve 314, the second pressure control solenoid valve 312 is energized by the controller to move the second fine-tuning valve 314 to its in motion position. As a result, fluid can flow back through the second shift valve 348, filling and applying force to C5.

[0115] In the event of a power outage, the controller cannot control any of the solenoid valves. Consequently, when the transmission is in neutral, as in... Figure 4 As shown, the energized second shift valve 332 is de-energized, and thus the third shift valve 350 moves from its advancing position to its non-advanced position. Once the third shift valve 350 has moved to its non-advanced position, as in Figure 15 As shown, the main pressure is blocked by the shift valve (e.g., by the second valve section 2006), and hydraulic fluid no longer flows through the second shift valve 348 to the second fine-tuning valve 314. Therefore, even though the second pressure control solenoid valve 312 is a constant-high solenoid valve and outputs full pressure, there is still no hydraulic fluid available to continue filling and applying force to C5. Therefore, C5 vents through any one or all of its three venting paths, as described above.

[0116] As in Figure 15 As shown, the main pressure continues to flow to the third and fourth fine-tuning valves. Fluid can fill and exert force on C3 by the third pressure-controlled solenoid valve 316, which outputs full pressure to move the third fine-tuning valve 318 to its travel position. This is not the case for C4, because the fourth pressure-controlled solenoid valve 320 remains de-energized, and the fourth fine-tuning valve 322 therefore blocks the main pressure from filling C4. As a result, when the transmission is in neutral or parked and de-energized, C5 is vented and exerts force on C3, causing the control system 300 to default to the neutral state of C3.

[0117] One characteristic of this default C3 neutral state is that the range valve (i.e., the first shift valve 346) is in its non-advanced position, blocking fluid flow to the first fine-tuning valve 308 and the fifth fine-tuning valve 326. Furthermore, the third shift valve 350 is not engaged, blocking fluid flow to the second fine-tuning valve 314. Therefore, even when the first pressure control solenoid valve 308 and the second pressure control solenoid valve 312 output full pressure to their respective fine-tuning valves, the first shift valve 346 is configured to block the supply of hydraulic fluid, filling C1 and C6, and the third shift valve 350 is configured to block the supply of hydraulic fluid, filling C5. As a result, the positions of the first shift valve 346 and the third shift valve 350 effectively prevent the transmission from shifting into reverse or forward gear ranges.

[0118] Another aspect of this disclosure is the ability to detect valve position and default range via pressure switches. With shift valves, it is necessary to be able to detect the position of each shift valve to ensure that hydraulic fluid is directed to the correct path and to prevent unwanted torque transmission mechanisms from being filled and stressed. This is especially true in this disclosure, where a second shift valve multiplexes and controls both C2 and C5. Each pressure switch in the control system 300 can be pressurized by a control main pressure and moved between a first position and a second position. Each pressure switch is electrically connected to the controller to provide feedback to the controller based on the switch's position. As will be described below, the pressure switches can convey additional information to the controller, including low or high gain and the position of the boost valve 354.

[0119] exist Figure 3-17 In the control system 300, a first pressure switch 356 detects the position of a first shift valve 346, a second pressure switch 358 detects the position of a second shift valve 348, and a third pressure switch 360 detects the position of a third shift valve 350. A fourth pressure switch 362 detects the position of a third fine-tuning valve 318, and therefore whether C3 is engaged. If the transmission is operating in steady neutral while C5 is being applied, and the fourth pressure switch 362 detects that the third fine-tuning valve 318 has moved from its non-moving position to its moving position (and therefore, C3 will be applied), the controller can detect this movement via the fourth pressure switch 362.

[0120] In this embodiment, the fourth pressure switch 362 can change its state or position when the third fine-tuning valve 318 moves to a position near the midpoint between the fully driven and fully stationary positions. In this example, when the third fine-tuning valve 318 is stationary, the fourth pressure switch 362 can be vented. However, when the third fine-tuning valve 318 moves to its driven position, the control main pressure fills and pressurizes the fourth pressure switch 362, thereby sending a signal indicating this event to the controller. As noted above, reverse gear is achieved when force is applied to C3 and C5. Therefore, in neutral with force applied to C5, the controller receives a message from the fourth pressure switch 362 indicating that C3 will immediately begin to fill as the third fine-tuning valve 318 moves closer to its driven position. If the controller determines that reverse gear is undesirable, it can control C5 to vent and default to the C3 neutral state to prevent reverse gear. Therefore, the fourth pressure switch 362 provides good fault detection when operating in neutral.

[0121] The controller can also monitor different pressure switches to determine whether a particular valve is engaged. For example, if the first shift valve 346 moves to its engaged position, the first pressure switch 356 can detect this movement and transmit it to the controller. In this way, the controller can better control the control system 300 and ensure that the appropriate range is selected based on operator input. This is especially true in the case of a drive-by-wire system, where the operator can select a button to control the transmission from a stationary position to the first forward gear range. In this case, the controller can detect shifts within the range by monitoring the pressure switches.

[0122] Another feature of this disclosure is the use of a pressure switch with a multiplexing function of a second shift valve 348. As previously described, the second shift valve 348 is capable of controlling whether C2 or C5 is engaged. If the second shift valve is not in motion, C5 is engaged and C2 is vented. If the second shift valve 348 is in motion, C2 is engaged and C5 is vented. Depending on the position of the second shift valve 348, the second pressure switch 358 is pressurized or vented. In one embodiment, the second pressure switch 358 is vented when the second shift valve 348 is not in motion and pressurized when the second shift valve 348 is in motion. In an alternative embodiment, the second pressure switch 358 is pressurized when the second shift valve 348 is not in motion and vented when the second shift valve 348 is in motion. In any case, the second pressure switch 358 can change its state between venting and pressurizing when the second shift valve 348 reaches approximately a midway position between the in-motion and non-in-motion positions. In addition, the controller can detect the position of the second shift valve 348 and whether C2 or C5 can be filled and stressed based on whether the second pressure switch 358 is vented or pressurized.

[0123] Go to Figure 5 This illustrates one embodiment of a transmission control system 300 controlling the first forward gear range. In this embodiment, a primary pressure is supplied to the system 300 by a pressure source 302. The controller can send current to a first shift solenoid valve 330 and a second shift solenoid valve 332 to advance a first shift valve 346 and a third shift valve 350. The primary control pressure is fed from the two shift solenoid valves to all three shift valves, but only the first shift valve 346 and the third shift valve 350 move to their advancing positions. When the primary control pressure is fed to the second shift valve 348, the second shift valve 348 does not move from its inactive position. As described above, force is applied to C5 in neutral, and during this process, hydraulic fluid flows from a second trim valve 314 through one end of the second shift valve 348 to fill and apply force to C5. As fluid flows through the second shift valve 348, it is able to hydraulically hold or maintain the valve in this position. In other words, one of the aforementioned interlocks 1918 holds the valve in the proper position even if the main control pressure from the first shift solenoid valve 330 attempts to move the second shift valve 348. Therefore, in this first forward gear range (or simply, the first range), C5 remains in neutral.

[0124] The main pressure flows to the third and fourth fine-tuning valves 318 and 322 according to its normal flow path. Here, the controller does not energize the third pressure control solenoid valve 316 or the fourth pressure control solenoid valve 320, and therefore the corresponding fine-tuning valve blocks the main pressure feed into C3 or C4. In the same manner, the main pressure is fed to the first fine-tuning valve 310 through the shift valve, but the controller does not energize the first pressure switch 308, and C1 cannot be forceped because the first fine-tuning valve 310 blocks the main pressure. Finally, by applying force to C5 and maintaining the second shift valve 348 in its un-moved position with hydraulic fluid, the second shift valve 348 prevents fluid filling and applies force to C2. Therefore, no force is applied to C1-C4 in the first range.

[0125] exist Figure 5 In the illustrative embodiment, the controller does indeed send current to energize the fifth pressure control solenoid valve 324. In doing so, the fifth pressure control solenoid valve 324 is able to move the fifth fine-tuning valve 326 and the booster plug 328 to allow fluid to fill C6. Hydraulic fluid supplied by the pressure source 302 flows to the first shift valve 346, and by moving the first shift valve 346 to its travel position, fluid is able to flow to the fifth fine-tuning valve 326 and fill C6. Therefore, force is applied to C6 within a first range.

[0126] As described above, the second pressure switch 358 can communicate with the controller regarding the position of the second shift valve 348. Therefore, the controller can send current to the first and second shift solenoid valves, and based on feedback from the first pressure switch 356, the controller can detect movement of the first shift valve 346 to its travel position. However, when shifting from neutral to the first range, C5 remains under force and the second shift valve 348 does not move. For example, the controller can detect that the interlock acting on the second shift valve 348 is functioning properly, as long as the second pressure switch 358 remains vented (assuming it is vented in neutral). In this way, the pressure switches can communicate when the interlock is active.

[0127] Similarly, an interlock may exist at the other end of the second shift valve 348. Here, the interlock is inactive in the first range, but active in the seventh, eighth, and ninth ranges. The control main pressure fed from the third shift valve 350 acts on the top of the second shift valve 348 to hydraulically hold the second shift valve 348 within its travel range. Thus, the second pressure switch 358 can be pressurized by the valve in this position, and the controller can detect the interlock's activity based on the valve position.

[0128] exist Figure 6 In another embodiment of the first range, the control system 30 is shown to hydraulically operate the transmission. Figure 5 In this embodiment, the TCC solenoid valve 304 is de-energized, causing the main pressure to be blocked by the TCC fine-tuning valve 306. In this embodiment, there is no lock-up pressure supplied to the torque converter 202 of the transmission system 200. However, in Figure 6 In this configuration, the controller can send current according to any known method used to energize the TCC solenoid valve 304 and move the TCC trimmer valve 306 to its travel position. For example, in... Figure 6 As shown, the lock-up clutch pressure can be fed from the TCC trimmer valve 306 to the converter flow 214. Fluid can flow from the converter flow 214 through the converter in path 222 to hydraulically apply force to the lock-up clutch of the torque converter 202. The manner and operation of the lock-up clutch can be based on any known method. Furthermore, when the controller energizes or de-energizes the TCC solenoid valve 304, it can be based on any known algorithm or process based on speed, torque, range, etc. It should be noted that in Figure 6 In the embodiments, the forces applied to C5 and C6 are generally the same.

[0129] In the event of a power outage in the first range, no current is sent to energize the fifth pressure control solenoid valve 324, the first shift solenoid valve 330, or the second shift solenoid valve 332. As a result, the fifth fine-tuning valve 326 does not advance and blocks the fluid path to C6. C6 therefore vents. This is also shown in Figure 16In the case where the second shift solenoid valve 332 is de-energized, the third shift valve 350 does not advance and blocks the main pressure feed into the second fine-tuning valve 314. As a result, hydraulic fluid is no longer supplied to C5, and C5 is vented. Therefore, no fluid is supplied to C5 or C6, which were previously under force in the first range.

[0130] However, as previously described, the first and third pressure control solenoid valves are always-high solenoid valves, which output full pressure during a power-off event. With the main pressure fed into the third fine-tuning valve 318, C3 is filled and stressed when power is off. Furthermore, with the first pressure control solenoid valve 304 outputting pressure to the first fine-tuning valve 306, the main pressure can fill and stress C1 via the first shift valve 346. Therefore, when the control system 300 is operating in the first range and power is off, by venting C5 and C6 and stressing C1 and C3, the control system 300 defaults to the fifth range.

[0131] In another aspect of this disclosure, the control system 300 is capable of controlling gain actuation via the booster plug 328. In this respect, the control system 300 is capable of providing low clutch control gain in a ninth range and high clutch control gain in a third range. To do this, the booster plug 328 can be operably controlled to adjust the gain.

[0132] Prior to the C6, gain control was relevant when the torque transmission mechanism required different pressures for different ranges. For example, in a high range, the mechanism might only require 80 psi, but in a lower range, the same mechanism might require 230 psi to maintain torque. To achieve these different pressures, the gain could be adjusted on the clutch fine-tuning system. Furthermore, a pressure switch could be used to detect high or low gain and communicate it to the controller.

[0133] In the first, third, and ninth ranges, C6 is pressure-controlled by a fifth pressure-controlled solenoid valve 324 and a fifth fine-tuning valve 326. In the first range, C6 may require, for example, up to 250 psi to maintain torque, while in the ninth range, C6 may only require approximately 80 psi. These pressures are provided only as examples and may vary in different embodiments. Therefore, using these pressures is not intended to limit the scope of this aspect of the disclosure.

[0134] In the first range, the torque can be significantly higher than in the ninth range. In the ninth range, controllability and shift quality may be more important. Therefore, in the first range, the gain can be set to 2.78 to achieve higher clutch pressure, and in the ninth range, the gain can be set to 1.6. Again, these gain values ​​are not limiting and are provided only as examples of low and high gain values. Gain adjustment on the fine-tuning valve is possible due to the different regions on one or more parts of the valve. This has been partially described above regarding the shift valve and interlock.

[0135] Continuing with this example, assume the pressure-controlled solenoid valve can output 1000 kPa. In the lower range, a gain of 2.78 allows the fine-tuning system to output up to 2780 kPa. Similarly, in the higher range, a gain of 1.6 allows the fine-tuning system to output up to 1600 kPa. Therefore, there exists a relationship between the solenoid valve's output pressure (typically defined by the control pressure or main control pressure) and the actual clutch pressure. Lower clutch pressures result in better shift quality, but torque requirements in the lower range may necessitate higher clutch pressures to reduce or prevent clutch slippage.

[0136] In addition to the above, the pressure switch can also transmit the gain stage information to the controller. Regarding the fifth fine-tuning valve 326, the second pressure switch 358 can detect its position. In the first range ( Figure 5 and 6 ) and the third range ( Figure 8 In this configuration, the output pressure from the fifth pressure control solenoid valve 324 forces the fifth fine-tuning valve 326 and the pressure boosting plug 328 into a downward or traveling position, where "downward" is only relative to the manner in which the valve and plug are shown in the accompanying drawings. Figure 8 For example, there is no primary pressure applied to the second pressure switch 358. Based on this, the controller is able to detect setting the fifth fine-tuning system to its high-gain level.

[0137] However, in the ninth range ( Figure 14 In this process, a control main pressure is fed in to pressurize the second pressure switch 358. The same control main pressure is also fed into a booster plug 328, through which hydraulic fluid can flow via a channel 344 defined within the booster plug 328. As a result, the hydraulic fluid separates the booster plug 328 from the fifth fine-tuning valve 326 and moves the plug 328 toward the fifth pressure control solenoid valve 324. In this condition or state, the fine-tuning system is at a lower gain value, and the second pressure switch 358 detects this value and transmits it to the controller.

[0138] The high / low gain actuation of the fifth fine-tuning system allows for lower clutch pressure control in the ninth range to improve shift quality and controllability, and higher clutch pressure control in the first and third ranges to reduce or prevent clutch slippage. Due to the higher gain, this further allows for complete engine torque clutch control during shifts from neutral to the first range, without requiring any additional hardware or actuators for detecting the gain setting. The second pressure switch 358 is therefore able to detect the position of the second shift valve 348 and the gain setting of the fifth fine-tuning valve 326.

[0139] See Figure 7 This indicates the second forward gear range, or simply, the second range. Here, the control system 300 is able to selectively control the filling of hydraulic fluid and apply force to C1 and C5. In the first range, force is applied to C5 and C6 to shift or change gears to the second range, venting C6 and applying force to C1.

[0140] To shift to the second range, the controller can energize the second shift solenoid valve 332, which pressurizes and propels the third shift valve 350. The first shift solenoid valve 330 may not receive current in the second range and therefore does not feed the main control pressure into the head of either the first or second shift valve. However, this timing may vary depending on the embodiment. For example, the controller may delay de-energizing the first shift solenoid valve 330 until the high-speed shift from the first range to the second range is complete. Once the shift is complete, the controller can then de-energize the first shift solenoid valve 300. Therefore, when Figure 3-17 The illustrative embodiment illustrates that, when one of the two shift solenoid valves is energized or de-energized, the controller can control the timing of when the corresponding solenoid valve is energized and de-energized to allow various gear shifts of the transmission to be completed. Software, control algorithms, calibration methods, instructions, tables, graphs, etc., can be stored in the memory unit 144 of the controller 142 and executed in any known manner to control the timing of sending current to any of the solenoid valves in the control system 300.

[0141] In any case, within the second range, the controller energizes the first pressure control solenoid valve 308 and the second pressure control solenoid valve 312 to move the first fine-tuning valve 310 and the second fine-tuning valve 314 to their respective travel positions. The third pressure control solenoid valve 316, the fourth pressure control solenoid valve 320, and the fifth pressure control solenoid valve 324 are de-energized, and their respective fine-tuning valves are in their non-travel positions to prevent hydraulic fluid from filling and applying force to C3, C4, and C6, respectively.

[0142] For hydraulic fluid flowing through the control system 300, the main pressure is again fed into the first shift valve 346 and the third shift valve 350 by the pressure source 302, as in Figure 7As shown in the diagram, hydraulic fluid flows through the third shift valve 350 in the same manner as in the first range. In doing so, it may flow through the second shift valve 348 (e.g., between the first valve portion 1904 and the second valve portion 1906) to the second fine-tuning valve 314. Through the second fine-tuning valve 314 in its traveling position, the hydraulic fluid can be fine-tuned to the desired clutch pressure and redirected back to the second shift valve 348. As the fluid flows back to the second shift valve 348, it may flow between the fourth valve portion 1904 and the fifth valve portion 1912 when it fills and applies force to C5. When the hydraulic fluid fills and applies force to C5, it flows back through the second shift valve 348, and specifically, on the underside of the sixth valve portion 1918, to keep the second shift valve inactive while it flows to the underside of the booster valve 354 to keep the booster valve 354 inactive. The operation of the booster valve 354 is further described below. The hydraulic fluid acting on the bottom side of the sixth valve section 1918 of the second shift valve 348 can act as an interlock 1918.

[0143] To fill C1, the first shift valve 346 is in its travel position, similar to its position in the first range. When fluid is fed into the first trimmer valve 310, hydraulic fluid from source 302 can thus flow into the first shift valve 346 (e.g., between the second valve portion 1806 and the third valve portion 1808) and through the second shift valve 348 (e.g., between the second valve portion 1906 and the third valve portion 1908). The hydraulic fluid can fill and force C1 via the first trimmer valve 310, which is traveled due to the first pressure-controlled solenoid valve 308. When the fluid forces C1, the hydraulic fluid is fed back to the first shift valve 346. While this is happening, it can flow between the fifth valve portion 1812 and the sixth valve portion 1814, forming an interlock 1820 to maintain the first shift valve 346 in its travel position.

[0144] In the event of a system power failure, the normally low-pressure solenoid valves (i.e., solenoid valves 320 and 324) are de-energized and output zero pressure, while the normally high-pressure solenoid valves (i.e., solenoid valves 308, 312, and 316) are de-energized but still output full pressure. As a result, the main pressure is still fed into the third fine-tuning valve 318, and hydraulic fluid can fill and apply force to C3 when it is moved to its travel position by the third pressure-controlled solenoid valve 316.

[0145] During the power outage, the first shift solenoid valve 330 and the second shift solenoid valve 332 are de-energized, thus moving the third shift valve 350 to its non-advanced position. In effect, the main pressure is now blocked by the third shift valve 350, as in... Figure 16As shown, fluid cannot flow to the second shift valve 348 and the second fine-tuning valve 314. As a result, C5 vents through either of its aforementioned venting paths. C1 remains under stress while hydraulic fluid flows from source 302 through the first and second shift valves to the first fine-tuning valve 310. Therefore, in the event of a power failure, forces are applied to C1 and C3 to achieve the fifth range. In this case, forces are not applied to C2, C4, C5, and C6.

[0146] As described above, the third shift valve 350 is used to block hydraulic fluid from being fed into the second fine-tuning valve 314, and therefore neither C2 nor C5 can be stressed. Although the main pressure can be fed into the fourth and fifth fine-tuning valves, their corresponding normally low solenoid valves are de-energized and therefore output zero pressure. As a result, the fourth fine-tuning valve 322 blocks fluid from filling C4, and the fifth fine-tuning valve 326 blocks fluid from filling C6.

[0147] See Figure 8 The control system 300 can operatively control the transmission in the third forward gear range (or simply, the third range). In the third range, forces are applied to C1 and C6. The main pressure is supplied by pressure source 302 to the same flow path in system 300 as described above. The controller can energize the first pressure control solenoid valve 308 and the fifth pressure control solenoid valve 324. Consequently, the first pressure control solenoid valve 308 outputs pressure to move the first fine-tuning valve 310 to its advancing position. Similarly, the fifth pressure control solenoid valve 324 outputs pressure to move the fifth fine-tuning valve 326 to its advancing position. The second pressure control solenoid valve 312, the third pressure control solenoid valve 316, and the fourth pressure control solenoid valve 320 are de-energized, and therefore their corresponding fine-tuning valves are positioned in their non-advanced positions.

[0148] The main pressure is blocked by the third fine-tuning valve 318 and the fourth fine-tuning valve 322, and therefore the pressure cannot be filled and apply force to C3 and C4 respectively. The first shift solenoid valve 330 and the second shift solenoid valve 332 are also de-energized in the third range, and therefore the third shift valve 350 does not move. With the third shift valve 350 not moving, the main pressure cannot flow to the second fine-tuning system, and C2 and C5 are thus disengaged.

[0149] The main pressure does flow into the first shift valve 346 and the second shift valve 348. As a result, hydraulic fluid can flow through the first and second fine-tuning valves and feed into C1 via the traveling first fine-tuning valve. If the transmission is shifting from the second range to a higher gear in the third range, C1 is filled and stressed. The hydraulic fluid from C1 backfills into the first shift valve 346 and acts on the differential region of the first shift valve 346 to form an interlock and maintain the valve's traveling state.

[0150] Hydraulic fluid can also be fed from the first shift valve 346 to the fifth fine-tuning valve 326. By moving the fifth fine-tuning valve 326 to its travel position, fluid can fill and apply force to C6. Therefore, force is applied to C1 and C6 in the third range.

[0151] In the event of a controller power failure, the control system 300 is configured to control the transmission to the fifth range via forces applied to C1 and C3. During this process, current is no longer sent from the controller to any of the solenoid valves. Therefore, the normally low pressure control solenoid valve and the first and second shift valves are de-energized and output zero pressure. C6 is thus vented when the fifth fine-tuning valve 326 is not in motion. C4 similarly remains unfilled, with the fourth fine-tuning valve 322 blocking the main pressure. Since the second shift solenoid valve 332 is de-energized, the third shift valve 350 is positioned in its non-moving position, thereby blocking hydraulic fluid flow to the second fine-tuning valve 314. Even if the second pressure control solenoid valve 312 outputs full pressure during a power failure event, hydraulic fluid is still blocked by the third shift valve 350, and neither C2 nor C5 is force-bearing.

[0152] In the third range, force is applied to C1, and the hydraulic fluid fed into C1 is further fed back to the first shift valve 346, which is held in the traveling position based on the interlock formed therein. The first fine-tuning valve 310 remains in the traveling position because the first pressure control solenoid valve 308 outputs full pressure, and C1 is thus held in force. Furthermore, the third pressure control solenoid valve 316 outputs full pressure in the de-energized state, thereby moving the third fine-tuning valve 318 to its traveling position. Since the main pressure is directly fed into the third fine-tuning system, hydraulic fluid can fill and apply force to C3. As a result, forces are applied to C1 and C3 in the de-energized state, and the control system 300 defaults to the fifth range.

[0153] See Figure 9 This illustrates a control system 300 in an embodiment where the transmission is controlled in the fourth forward gear range or fourth range. In the fourth range, forces are applied to C1 and C4. To do this, the controller energizes the first pressure control solenoid valve 308 and the fourth pressure control solenoid valve 320. The first pressure control solenoid valve 308 outputs pressure to move the first fine-tuning valve 310 to its driving position, and the fourth pressure control solenoid valve 320 outputs pressure to move the fourth fine-tuning valve 322 to its driving position. The other pressure control solenoid valves and the two shift solenoid valves are de-energized. Therefore, no force is applied to C3 and C6 because the third fine-tuning valve 318 and the fifth fine-tuning valve 326 are not engaged, and fluid filling of either clutch is blocked. Furthermore, the third shift valve 350 is not engaged by the de-energized second shift solenoid valve 332, which blocks the main pressure feed into the second fine-tuning system. As a result, neither C2 nor C5 can be engaged in the fourth range.

[0154] The main pressure is provided by pressure source 302 and directly fed into the fourth fine-tuning system, such as in Figure 9 As shown in the diagram, hydraulic fluid can fill and apply force to C4 via the fourth fine-tuning valve 322 in its traveling position. Furthermore, although the first shift solenoid valve 330 is de-energized, force is applied to C1 via hydraulic fluid flowing through the first and second shift valves to the first fine-tuning system. With the filling of C1, hydraulic fluid flows back to the first shift valve 346, and clutch pressure acts on the differential region of the first shift valve 346 (e.g., between valve portions 1812 and 1814) to form an interlock 1820 and maintain the shift valve in its traveling position. Therefore, force is applied to C1 and C4 in the fourth range.

[0155] When the controller is de-energized, and the controller cannot send current to energize the fourth pressure control solenoid valve 320, pressure C4 is released. Since the fourth pressure control solenoid valve 320 can be a normally low solenoid valve, when it is de-energized, it outputs zero pressure to the fine-tuning valve. Therefore, the fourth fine-tuning valve 322 does not advance and prevents hydraulic fluid from filling C4. Similarly, since the fifth fine-tuning valve 326 does not advance and blocks fluid, C6 remains unforced.

[0156] Similar to the first, second, and third ranges described above, the first and second shift solenoid valves are de-energized, thereby placing the third shift valve 350 in its non-advanced position. As a result, hydraulic fluid is blocked by the third shift valve 350 and cannot be fed into the second fine-tuning system. Therefore, no force is applied to C2 and C5 in the de-energized state.

[0157] Additionally, the third pressure control solenoid valve 316 is energized and outputs full pressure in the de-energized state. This moves the third fine-tuning valve 318 to its travel position, and because the main pressure is directly fed into the third fine-tuning system, fluid can fill and exert force on C3.

[0158] C1 is continuously fed with hydraulic fluid to maintain force during power-off conditions. Even if the first shift valve 346 does not receive the main control pressure from the first shift valve 330, the pressure filling and applying force to C1 still flows back and acts on the differential region of the first shift valve 346 to form an interlock 1820 and hold the first shift valve 346 in its traveling position. As a result, when the control system 300 operates in the fourth range and is de-energized, the control system 300 defaults to the fifth range (see [link to control system]) by the applied forces C1 and C3. Figure 16 ).

[0159] exist Figure 10The diagram illustrates a control system 300 in another embodiment, wherein it is operatively controlling the transmission in a fifth forward gear range or a fifth range. As previously described in several of the embodiments above, the fifth range can be obtained by applying forces to C1 and C3. The fifth range also happens to be the default range during a power outage when the control system 300 is operatively controlling the transmission in the first, second, third, and fourth ranges. Therefore, for the purposes of this disclosure, the fifth range may also be referred to as a low-range default. When power is off and the transmission is in reverse or neutral, the control system 300 can operate differently, and this has been described above, wherein the control system 300 defaults to the C3 neutral state. Here, in the lower forward gear ranges (i.e., the first to fifth ranges), the control system 300 defaults to the fifth range in the event of a power outage. It should be noted that other default ranges may be possible, and only one embodiment of this embodiment is illustrated and described herein.

[0160] To operably control the transmission in the fifth range, the controller can energize the first pressure control solenoid valve 308 and the third pressure control solenoid valve 316. In doing so, each solenoid valve is actuated and moves the first fine-tuning valve 310 and the third fine-tuning valve 318 to their respective travel positions. The main pressure is supplied directly to the third and fourth fine-tuning systems by the pressure source 302, as in... Figure 10 As shown in the diagram. Hydraulic fluid can fill and apply force to C3 via the third fine-tuning valve 318 in its traveling position. On the other hand, the fourth fine-tuning valve 322 is in its non-traveling position, thereby preventing fluid from filling C4. Similarly, the fifth fine-tuning valve is not traveling, thereby preventing fluid from filling and applying force to C6.

[0161] By interrupting the power to the first and second shift solenoid valves in the fifth range, the main control pressure is not supplied to the head end of any of the three shift valves. Consequently, the third shift valve 350 does not advance, and the supply of hydraulic fluid to the second fine-tuning system is blocked. Since no hydraulic fluid can flow through the third shift valve 350, no force is applied to C2 and C5.

[0162] In the fifth range, force is applied to C1, and this is done by hydraulic fluid flowing through the first and second shift valves before being fed into the first fine-tuning system. With the first fine-tuning valve 310 in its traveling position, hydraulic fluid can fill and apply force to C1. The pressure of C1 (as in...) Figure 10 The flow (as shown) can return to the first shift valve 346, as in the second, third, and fourth ranges. Here, the C5 pressure acts on the differential region (e.g., the sixth valve portion 1814) of the first shift valve 346 to form an interlock 1820, which hydraulically holds or maintains the first shift valve 346 in its travel position.

[0163] Unlike the previously described forward gear ranges, when power is off and the controller cannot send current to any of the solenoids in the control system 300, the same two torque transmission mechanisms (i.e., C1 and C3) remain under force when the transmission is operating in the fifth range. In other words, when the transmission is not operating in the fifth range and power is off, the default is the fifth range and therefore there is no shift to another range. In the power-off state, C4 and C6 remain unforced because the normally low fourth pressure control solenoid 320 and normally low fifth pressure control solenoid 324 output zero pressure, and the corresponding fine-tuning valves remain unmoved to prevent hydraulic fluid from filling C4 and C6. Furthermore, the second shift solenoid 332 is de-energized, thereby causing the third shift valve 350 to not move. When the third shift valve 350 is not moving, hydraulic fluid cannot flow to the second fine-tuning system and fill C2 or C5. Therefore, no force is applied to C2 and C5 in the power-off state.

[0164] The constant-pressure control solenoid valve can output full pressure in the de-energized state. Therefore, the first pressure control solenoid valve 308 and the third pressure control solenoid valve 316 output full pressure, thereby positioning the first fine-tuning valve 310 and the third fine-tuning valve 318 in their travel positions. This allows hydraulic fluid to fill and exert force on C1 and C3 in the same manner as in the steady-state fifth range described above.

[0165] In this disclosure, when power is lost, the control system 300 may default to three default ranges. The first default range is C3 neutral, and as described above, this range is selected when the transmission is operating in reverse or neutral before power loss. The second default range is a fifth range in which forces are applied to C1 and C3, and this occurs when the transmission is in the first, second, third, fourth, and fifth ranges. The third default range is a seventh range, and this occurs during power loss when the transmission is operating in the sixth, seventh, eighth, or ninth range. These subsequent forward gear ranges and the third default range will be described below. However, it should be understood that these default ranges apply to the illustrative embodiments provided herein. Other embodiments of the control system may default to other ranges. For example, fewer than three default ranges may exist, or in some examples, more than four default ranges may exist. Therefore, the principles and teachings of this disclosure are not intended to be limited to a particular default range or any number of default ranges.

[0166] Go to Figure 11The control system 300 is operable to control the transmission in the sixth forward gear range or within the sixth range. Here, the second shift valve 348 is actuated to its driving position to allow C2 to fill and be stressed. Furthermore, force is applied to C1 in the sixth range. For C1, the controller can energize the first pressure control solenoid valve 308, which moves the first fine-tuning valve 310 to its driving position. Additionally, the second pressure control solenoid valve 312 can be energized, thereby moving the second fine-tuning valve 314 to its driving position. Simultaneously, the third pressure control solenoid valve 316, the fourth pressure control solenoid valve 320, and the fifth pressure control solenoid valve 324 are de-energized. Therefore, the hydraulic fluid is blocked by the third fine-tuning valve 318, the fourth fine-tuning valve 322, and the fifth fine-tuning valve 326, which effectively prevents C3, C4, and C6 from filling and being stressed.

[0167] In this embodiment, the first and second shift solenoid valves are energized. As shown, the main control pressure is fed from the main control filter 336 to the first shift solenoid valve 330 and the second shift solenoid valve 332. Then, the main control pressure is fed to the heads of the first shift valve 346, the second shift valve 348, and the third shift valve 350. All three shift valves thus move to their travel positions. Through the third shift valve 350 in its travel position, as shown in... Figure 17 The shift valve shown feeds in the main pressure and to the second shift valve 348. Hydraulic fluid can flow through the second shift valve 348 to the first fine-tuning system, and through the first fine-tuning valve 310 in its travel position, the fluid can fill and apply force to C1.

[0168] In the same manner, hydraulic fluid from pressure source 302 can flow directly to the first shift valve 346. Passing through the first shift valve 346, the fluid can flow to the second shift valve 348, and there to the second fine-tuning system. Passing through the second fine-tuning valve 314 in its travel position, the hydraulic fluid can flow through the second fine-tuning valve 314 and return to the second shift valve 348, where it fills and applies force to C2. The C2 pressure further flows to the first shift valve 346 and acts on another differential region of the first shift valve 346 (e.g., between the fourth valve portion 1810 and the fifth valve portion 1812) to form another interlock 1818 on the first shift valve 346. Therefore, in the sixth range, forces are applied to C1 and C2.

[0169] When hydraulic fluid flows to the second fine-tuning system and the second fine-tuning valve 314 is in its travel position, hydraulic fluid can flow to the booster valve 354. The booster valve 354 can be used to "boost" or increase clutch pressure to allow the torque transmission mechanism to handle high-torque operating modes. Figure 11In the illustrative embodiment, force is applied to C2 to cover the highest torque operating mode, while C5 can be designed so that it cannot handle such torque modes. C5 can be damaged due to compressive rupture from the increased pressure, and therefore the control system 300 can be designed to prevent the booster valve 354 from being actuated when C5 is engaged. In fact, whether the booster valve 354 is stressed is a gain control form of the second fine-tuning system, which differs from the aforementioned gain control form of the fifth fine-tuning system.

[0170] In at least one instance, the C5 pressure needs to be limited to below the main pressure, while the C2 pressure needs to be approximately equivalent to the main pressure in at least one forward gear range. In another instance, the C2 and C5 pressures may be less than the main pressure, but the C2 pressure can be greater than the C5 pressure when the booster valve is actuated. In yet another instance, the booster valve is actuated (or traveled) when C2 is stressed, and de-actuated (or not traveled) when C5 is stressed.

[0171] By using a lower C5 pressure, the control system 300 can better provide improved shift quality and controllability. Additionally, the second pressure control solenoid valve 312 and the second fine-tuning valve 314 can further fine-tune the C5 pressure (if necessary). Therefore, the C5 pressure is more controllable via the untraveled booster valve 354. However, as in... Figure 7 As shown, there is no solenoid valve for independently controlling the movement of the booster valve 354. Therefore, in the illustrative embodiment, the C5 pressure can be used as a blocking feature or mechanism to prevent the booster valve 354 from moving to its traveling position when force is applied to C5. For example, in the second range, the main pressure is fed into the second fine-tuning system through the second and third shift valves. Hydraulic fluid flows through the second fine-tuning valve 314 and returns to the second shift valve 348, where it fills and applies force to C5. Once C5 is filled, fluid can flow back to the second fine-tuning system and flows to the bottom side of the booster valve 354. The C5 pressure thus advances or forces the booster valve 354 to remain in its non-traveling position, thereby limiting the pressure of C5. The blocking feature or mechanism of the C5 pressure acting on the booster valve 354 is similar to an interlock, except that here it hydraulically holds or maintains the booster valve 354 from moving to its traveling position. In contrast, the interlock described in this article is hydraulic pressure, which hydraulically holds or maintains the valve in its travel position and prevents it from moving to its non-travel position.

[0172] By hydraulically retaining the pressure booster valve 354 to prevent it from moving to its travel position, the C5 pressure can be reduced and maintained below the main pressure. In one embodiment, the output of the second pressure control solenoid valve 312 can be limited to any pressure higher than the main control pressure. The second trimmer valve 314 may have an associated gain such that the C5 pressure can be greater than the main control pressure. For example, if the gain is 1.25 and the main control pressure is 1000 kPa, then the C5 pressure could be 1250 kPa. The gain can be a function of the differential region on the second trimmer valve 314.

[0173] exist Figure 11 In this configuration, the booster valve 354 can be active, and the pressure C2 can be approximately the main pressure. Here, when the main pressure is fed into the second fine-tuning system and fluid flows through the second fine-tuning valve 314, it also flows to the booster valve 354. This flow to the booster valve 354 causes it to move to its travel position. Furthermore, due to the force of C5, there is no hydraulic fluid supplied to the bottom side of the booster valve 354. The booster valve 354 is thus able to move to its travel position, allowing for an increased pressure C2. In the case of the second fine-tuning valve 314, the same gain is obtained, but with the booster valve 354 now in motion, the second fine-tuning valve 314 can move even further to its fully travel position, for example, such that the main pressure is fed into C2. In fact, with the booster valve 354 active, the second fine-tuning valve 314 can travel further, such that the main pressure is fed into C2. In contrast, the second fine-tuning valve 314 is moved by force C5, but to a much smaller extent, because the booster valve 354 is not in an active state.

[0174] Tolerances in the second fine-tuning system can be provided by limiting the second pressure control solenoid valve 312 or by other tolerances in the main and control main circuits.

[0175] Before returning to the sixth range, it is further shown here that a second shift valve 348 may be provided to limit or prevent C2 and C5 from being stressed simultaneously. In effect, this provides fail-mode protection by allowing only one of the two torque transmission mechanisms to be stressed at a time.

[0176] In the sixth range, the control system 300 operably controls the transmission via forces applied to C1 and C2. In the event of a power outage, the controller may be unable to send current to either of the solenoid valves. (As in...) Figure 17As shown, when operating in the sixth range, an alternative default range is available in the event of a power outage. In this case, both the first shift solenoid valve 330 and the second shift solenoid valve 332 are de-energized. Consequently, the third shift valve 350 moves to its non-traveled position and blocks the flow of hydraulic fluid to C1. In effect, the third shift valve 350 blocks fluid from reaching the first fine-tuning system and therefore cannot apply force to C1.

[0177] When power is off, the normally low fourth pressure control solenoid valve 320 and the fifth pressure control solenoid valve 324 are de-energized, and therefore neither solenoid valve outputs any pressure. As a result, the fourth and fifth fine-tuning valves are in their non-advanced positions and block the main pressure feed into C4 or C6. Therefore, as described herein, when operating in the sixth range and when power is off, no force is applied to C1, C4, C5, and C6. Therefore, force is applied to C2 and C3 in the high default range corresponding to the seventh range.

[0178] Because as in Figure 17 The main pressure shown is directly fed into the third fine-tuning system, applying force to C3 within this default range. Furthermore, the third pressure control solenoid valve 316 can be a constant-high solenoid valve, and therefore outputs full pressure when de-energized. In this process, the third fine-tuning valve 318 is actuated to its travel position, thereby allowing hydraulic fluid to fill and apply force to C3.

[0179] As described above, a force is applied to C2 in the sixth range. The pressure of C2 can create an interlock between the first shift valve 346 and the second shift valve 348 in the sixth range. For example, see... Figure 18 and 19 The C2 pressure can form an interlock 1818 on the first shift valve 346 and another interlock 1916 on the second shift valve 348. Therefore, even when the main control pressure is cut off when the first shift solenoid valve 330 is de-energized, the C2 pressure is still able to hold the first and second shift valves in their traveling positions due to the interlocks in the high default range. Since the shift valve 348 is latched in the traveling position, the main feed to C5 is blocked.

[0180] If still Figure 17 As shown, the booster valve 354 can travel fully, allowing the C2 pressure to be approximately equal to the main pressure. The second fine-tuning system can adjust the C2 pressure as needed, but it is worth noting that the second fine-tuning valve 312 and the booster valve 354 are in their travel positions.

[0181] See now Figure 12 This illustrates a control system 300 that operably controls the transmission within the seventh forward gear range (i.e., the seventh range). Within the seventh range, forces are applied to C2 and C3 as described above. Figure 12In the seventh range of normal or stable states shown, the controller can energize the second pressure control solenoid valve 312 and the third pressure control solenoid valve 316. Furthermore, the first pressure control solenoid valve 308, the fourth pressure control solenoid valve 320, and the fifth pressure control solenoid valve 324 are de-energized. The controller further energizes the first shift solenoid valve 330 but de-energizes the second shift solenoid valve 332.

[0182] Hydraulic fluid can be fed into the control system 300 via a fluid pressure source 302, which, as described above, can be supplied by a hydraulic pump 204 of the transmission system 200. From the pressure source 302 (which may be further referred to as the main pressure line of the control system 300), hydraulic fluid can be directly fed into the first shift valve 346, the third shift valve 350, the third fine-tuning system, and the fourth fine-tuning system. When the third pressure control solenoid valve 316 is energized, the third fine-tuning valve 318 can be moved to its forward or open position to allow hydraulic fluid to fill and apply force to C3.

[0183] By de-energizing the first, fourth, and fifth fine-tuning systems, the corresponding fine-tuning valves can block the hydraulic fluid from filling C1, C4, and C6. However, due to the de-energization of the second shift solenoid valve 332, hydraulic fluid can be blocked upstream via C1 through the third shift valve 350, which is in its non-progressing position.

[0184] By energizing the first shift solenoid valve 330, the main control pressure can be fed into the heads of each of the first and second shift valves, thereby moving both shift valves to their travel positions. The main pressure can be fed directly into the first shift valve from the pressure source 302. Through the travel of the first shift valve 346, hydraulic fluid can flow through the first shift valve 346 and the second shift valve 348 to the second fine-tuning system. Since the second pressure control solenoid valve 312 is energized, the second fine-tuning valve 314 is in its travel position, and thus hydraulic fluid can flow through the second fine-tuning system back to the second shift valve 348, filling and applying force to C2. Furthermore, the hydraulic fluid flowing through the second fine-tuning valve further flows to the booster valve 354, causing the booster valve 354 to travel to its travel position. By venting C5, there is no hydraulic pressure resisting the booster valve 354 moving to its travel position. As a result, the pressure of C2 can be increased or boosted to approximately the main pressure.

[0185] If still Figure 12 As shown, C2 pressure flows through the first shift valve 346 and the second shift valve 348, acting on the differential regions or areas of the two valves. In effect, the C2 pressure acting on these differential regions creates an interlock on the two valves to hold them in place. Since control pressure is still fed into the heads of each of the first and second shift valves, the interlock may be unnecessary in the seventh range, but the C2 pressure fills and applies hydraulic pressure to the differential regions of the two valves.

[0186] In the event of a power outage, the control system 300 can also default to the seventh range. Therefore, when the transmission is in the seventh range and power is off, the transmission does not shift gears and instead remains in the seventh range where C2 and C3 are under force. The normally high pressure control solenoid valve defaults to full output pressure, and the normally low pressure control solenoid valve defaults to zero output pressure. Therefore, since the fourth and fifth fine-tuning valves block hydraulic fluid, no force is applied to C4 and C6 in the event of a power outage. Furthermore, the first and second shift solenoid valves are de-energized, and therefore the third shift valve 350 is in its non-operating position. Consequently, the third shift valve 350 blocks hydraulic fluid from filling C1.

[0187] In the event of a power outage, the second pressure control solenoid valve 312 and the third pressure control solenoid valve 316 output full pressure. Since the main pressure is directly fed into the third fine-tuning system, hydraulic fluid can fill and apply force to C3. Furthermore, as described above, pressure C2 interlocks the first shift valve 346 and the second shift valve 348. Therefore, even if the first shift solenoid valve 330 is de-energized and no longer supplies the main control pressure to the head of the first or second shift valve, the interlock formed by pressure C2 still maintains both shift valves in their traveling positions. Because the C2 latch holds shift valve 348 in the traveling position, the main pressure is blocked from being fed into C5.

[0188] If still Figure 17 As shown, when the first shift solenoid valve 330 is de-energized in the event of a power failure, the control main pressure can be slowly released, and an interlock is still applied at the head of the second shift valve 348 as it flows through the fluid path via the third shift valve 350. In practice, in this embodiment, a high-speed logic valve latch or interlock can be applied to the second shift valve 348 to maintain it in its traveling position. The slow release of the control main pressure may be partly due to the check valve 352 and the restriction in the fluid path. When operating in the seventh range, hydraulic fluid at the control main pressure can be fed directly from the control main valve 334 to the main modulation solenoid valve 340 and the third shift valve 350. This same flow path will be described below with respect to the actuation of the booster plug 328.

[0189] In either case, hydraulic fluid at the control of the main pressure can flow through the third shift valve (e.g., between the third valve section 2008 and the fourth valve section 2010) and through the first parallel check valve 352 (in Figure 17The first check valve 352 may include a check ball that allows flow from the third shift valve 350 to the second shift valve 348, but prevents backflow of hydraulic fluid from the second shift valve 348 to the third shift valve 350. As a result, when power is interrupted in the seventh range (or the sixth, eighth, and ninth forward gear ranges) and the first and second shift solenoid valves are de-energized, the hydraulic pressure at the control main pressure at the heads of the first shift valve 346 and the second shift valve 348 cannot flow back through the third shift valve 350 due to the first check valve 352.

[0190] As if in Figure 17 As shown, the second check valve 352 is located directly above the second shift valve 348. This second check valve 352 also includes a check ball that allows fluid to flow from left to right in the drawing, but the ball is positioned within the valve to prevent flow from right to left. Although not yet in... Figure 17 As shown, however, there is a flow restriction in the parallel flow path directly below the second check valve 352, causing a portion of the hydraulic fluid to flow from the second shift valve 348 to the first shift valve 346 (i.e., in...). Figure 17 (From right to left). This is shown in Figure 17 In this configuration, hydraulic fluid flowing to the left of the restriction is shown as discharge, and hydraulic fluid flowing to the right of the restriction is shown as control main pressure. As a result, due to the restriction and the second check valve 352, hydraulic fluid at the control main pressure at the top or head of the second shift valve 348 is slowly discharged. Therefore, the hydraulic pressure is high enough to form a latch or interlock to hold the second shift valve 348 in its traveling position. C2 can vent in this case, but both the first and second shift valves remain in their traveling positions. In other embodiments, additional components may be included to limit discharge in the control system 300.

[0191] It should be further noted that if C2 venting is permitted, high-speed C3 neutral can be achieved without any actuation or movement of the first shift valve 346 or the second shift valve 348. Therefore, although it has been described herein that defaulting to the seventh range is feasible when operating in the higher range, the control system 300 can also default to high-speed neutral in the event of a power failure or power outage. Additionally, the second pressure switch 358 can be continuously pressurized, enabling the controller to detect the position of the second shift valve 348 in the event of a failure or power outage.

[0192] In addition to the high-speed neutral gear with only C3 under force, the control system may also default to the seventh range, with both C2 and C3 under force. For example, suppose the operator is operatively controlling the transmission in a higher forward gear range such as the sixth, seventh, eighth, or ninth range. If the operator shifts to neutral but power is suddenly interrupted, the control system may be adapted to operatively control the transmission to the aforementioned high-speed C3 neutral gear. Alternatively, the control system may determine that the shift to neutral was accidental and maintain force on C2, causing the transmission to default to the high-speed power-off range of the seventh range. If the operator did shift to neutral, and the control system detects that this was the intended shift, then in the event of a power failure, C2 can be released and the transmission control system 300 may default to C3 neutral. Furthermore, if power is not interrupted, the control system may still terminate in C3 or C5 neutral.

[0193] See Figure 13 This illustrates a control system 300 that operably controls the transmission within the eighth forward gear range or the eighth range. In the eighth range, forces are applied to C2 and C4, but not to other torque transmission mechanisms. In this range, the controller can energize the second pressure control solenoid valve 312 and the fourth pressure control solenoid valve 320. The first, third, and fifth pressure control solenoid valves are de-energized. Additionally, the controller can energize the first shift solenoid valve 330 and de-energize the second shift solenoid valve 332.

[0194] The third shift valve 350, which is not in motion due to the de-energization of the second shift solenoid valve 332, blocks the flow of hydraulic fluid to the first fine-tuning system. Therefore, C1 is blocked from receiving fluid and thus not subjected to force. Additionally, the third pressure control solenoid valve 316 is de-energized, and therefore the third fine-tuning valve 318 is in its non-moving position. In this position, the main pressure from the pressure source 302 is blocked by the third fine-tuning valve 318, preventing fluid from filling and exerting force on C3. C3 is therefore not subjected to force in the eighth range.

[0195] The first shift valve 346 is directly and freely connected to the pressure source 302, and when the first shift solenoid valve 330 is energized, the first shift valve 346 is in its traveling position. Hydraulic fluid can therefore flow through the first shift valve 346 in several flow paths. The first flow freely connects the first shift valve 346 to the fifth fine-tuning system. When the fifth pressure control solenoid valve 324 is energized, this same fluid path is used to fill and apply force to C6. However, in the eighth range, the fifth pressure control solenoid valve 324 is de-energized, and the fifth fine-tuning valve 326 therefore blocks the fluid path and prevents hydraulic fluid from filling and applying force to C6. C6 is therefore not under force in the eighth range.

[0196] The main pressure can flow through different fluid paths from the first shift valve 346 to the second shift valve 348. Here, with the first shift solenoid valve 330 energized, the second shift valve 348 is actuated to its traveling position, and thus the second shift valve 348 is flowably connected to the pressure source 302. Hydraulic fluid can flow through the first and second shift valves to the second fine-tuning system. With the second pressure control solenoid valve 312 energized, the second fine-tuning valve 314 can travel, thereby allowing fluid to flow through the second fine-tuning valve 314. As it flows through the second fine-tuning valve 314, the fluid flows back to the second shift valve 348 and fills C2. C2 is therefore under force in the eighth range.

[0197] In addition to filling and applying force to C2, hydraulic fluid is fed into the booster valve 354 and actuates the boost pressure for C2. In some embodiments, this can increase the pressure of C2 to approximately the main pressure. If necessary, a second fine-tuning system can adjust or fine-tune the pressure of C2. Furthermore, the main pressure is blocked from being fed into C5 by the traveling second shift valve 348. Therefore, based on the position of the second shift valve 348, C5 cannot be forced within the eighth range.

[0198] The main pressure from fluid source 302 is directly fed into or can be connected to the fourth fine-tuning system. In the eighth range, the controller energizes the fourth pressure control solenoid valve 320, which actuates the fourth fine-tuning valve 322 to its travel position. In doing so, hydraulic fluid can fill the eighth range and apply force to C4. Therefore, forces are applied to C2 and C4 in the eighth range.

[0199] In the event of a power outage while operating in the eighth range, the control system 300 can be designed to default to the seventh range in a manner similar to operation in the sixth or seventh range. Here, C4 is vented, and force is applied to C3. As described, when power is lost, the three normally high-pressure control solenoid valves output full pressure, and the two normally low-pressure control solenoid valves output zero pressure. Furthermore, the two shift solenoid valves are de-energized.

[0200] When the second shift solenoid valve 332 is de-energized, the third shift valve 350 is positioned in its non-operational position. In its non-operational position, the third shift valve 350 blocks the flow of hydraulic fluid into C1. Additionally, the fourth and fifth fine-tuning valves 322 and 326 are not operated via the two de-energized, normally low-pressure control solenoid valves, thus blocking the flow of hydraulic fluid into C4 and C6. In other words, in the eighth range, the fourth pressure control solenoid valve 320 is energized by the controller, causing force to be applied to C4, but when de-energized, the controller no longer sends current to the fourth pressure control solenoid valve 320. Once this occurs, the fourth pressure control solenoid valve 320 outputs zero pressure to the fourth fine-tuning valve 322, thereby moving the fourth fine-tuning valve 322 from its operating position to its non-operational position. During this process, the fourth fine-tuning valve 322 blocks the filling of C4 with hydraulic fluid, and the pressure in C4 is thus released.

[0201] In the eighth range, C3 is not under force, but when power is off, the third pressure control solenoid valve 316 outputs full pressure to move the third fine-tuning valve 318 to its traveling position. During this process, the main pressure is fed into the third fine-tuning system, thus applying force to C3. Furthermore, C2 is under force in the eighth range and remains under force when power is off. The second pressure control solenoid valve is a constant-high solenoid valve, and therefore, it outputs full pressure to keep the second fine-tuning valve 314 traveling. The pressure of C2 further acts on the differential region of the first shift valve 346 and the second shift valve 348 to hydraulically hold the shift valve in its traveling position. In other words, an interlock is formed on the two shift valves to maintain travel. Shift valve 348 thus blocks the main feed of C5. With the first and second shift valves in motion, and with the first shift valve 346 directly and flowably connected to the pressure source 302, hydraulic fluid can continue to flow through the shift valves and the second fine-tuning system before returning to the second shift valve 348 and feeding into C2. Therefore, as in Figure 17 As shown, forces are applied to C2 and C3 in the high default range (i.e., the seventh range).

[0202] See Figure 14 The control system 300 is operable to control the transmission within the ninth forward gear range (i.e., the ninth range). Within the ninth range, forces can be applied to C2 and C6. To do this, the controller energizes the second pressure control solenoid valve 312 and the fifth pressure control solenoid valve 324. The first shift solenoid valve 330 is energized, but the second shift solenoid valve 332 is de-energized, as in... Figure 14As shown in the diagram, when the first shift solenoid valve 330 is energized, the main control pressure is fed into the heads of both the first shift valve 346 and the second shift valve 348 via the solenoid valve 330, thereby placing both valves in their travel positions. As will also be described below, pressure C2 can apply pressure to the differential regions on the two valves to interlock and hydraulically hold both the first and second shift valves in their travel positions.

[0203] When the second and fifth pressure control solenoid valves are energized, the second fine-tuning valve 314 and the fifth fine-tuning valve 326 are in their advancing positions. Conversely, when the first, third, and fourth pressure control solenoid valves are de-energized, the first fine-tuning valve 310, the third fine-tuning valve 318, and the fourth fine-tuning valve 322 are in their non-advanced positions. Furthermore, when the second shift solenoid valve 332 is de-energized, in the ninth range, the third shift valve 350 is in its non-advanced position.

[0204] As previously described, in the seventh and eighth ranges, the second shift solenoid valve 332 is de-energized, and as in Figure 14 As shown, it is also de-energized in the ninth range. By de-energizing it, the third shift valve 350 is positioned in its non-operating position, thereby preventing hydraulic fluid from flowing and filling C1. In effect, when the transmission is operating in the higher ranges (i.e., the seventh, eighth, and ninth ranges), C1 cannot be subjected to force, protecting the transmission from potential damage if C1 were to occur in any of these higher ranges. Therefore, the third shift valve 350 provides protective features for the control system 300 and the transmission.

[0205] Because the third pressure control solenoid valve 316 and the fourth pressure control solenoid valve 320 are de-energized, the third fine-tuning valve 318 and the fourth fine-tuning valve 322 do not advance, and thus prevent hydraulic fluid from filling C3 or C4. Therefore, in the ninth range, no force is applied to C3 and C4. Although this is the case, Figure 3-17 The diagram also shows that the main pressure is fed directly from the fluid source 302 to the third and fourth fine-tuning systems. For this purpose, Figure 21 Mechanized diagram 2100 illustrates that both C3 and C4 can be subjected to force in any range (i.e., reverse, neutral, or the first through ninth range). If the controller energizes only the third or fourth pressure control solenoid valve, hydraulic fluid will fill and exert force on C3 or C4. It is important to note that if de-energized, the normally low fourth pressure control solenoid valve 320 will be de-energized, and the output pressure will be zero. As described herein, when de-energized, the fourth fine-tuning valve 322 will not advance and will prevent fluid from filling C4.

[0206] anyway, Figure 21The mechanized chart 2100 provides the following overview: depending on which solenoid valves are energized by the controller, the torque transmission mechanism is available in each range. The chart also shows the corresponding hydraulic default range for each given steady-state range in the event of power failure. Another feature of the mechanized chart 2100 is the position of each shift valve. In this chart, zero (0) indicates that the shift valve is not in motion, while one (1) indicates that the shift valve is in its in motion position. In the ninth range, for example, the first and second shift valves are shown as in motion (1), and the third shift valve 350 is shown as not in motion (0). This is further explained by… Figure 14 The implementation examples support this.

[0207] Return to Figure 14 The first shift valve 346 is in its traveling position. Therefore, hydraulic fluid can be supplied directly from source 302 to the first shift valve 346. From the first shift valve 346, fluid can flow to the fifth fine-tuning system. As described above, the fifth fine-tuning valve 326 travels to allow fluid filling and apply force to C6. Although not in Figure 14 As shown, the valve gain of the fifth fine-tuning valve 326 is controllable, allowing the control main pressure to be fed into the pressure booster plug 328. The control main pressure flows through a channel 344 defined in the pressure booster plug 328 and applies force against the head of the fifth fine-tuning valve 326. In this process, the pressure booster plug 328 does not move to the travel position with the fifth fine-tuning valve 326, thereby altering the gain across the fine-tuning system. This contrasts with the first and third ranges when force is applied to C6. In those ranges, the control main pressure is not directly fed into the pressure booster plug 328, and in those lower ranges, the pressure booster plug 328 moves to the travel position with the fifth fine-tuning valve 326.

[0208] Figure 14The diagram generally illustrates the control master pressure flowing to the booster plug 328. This control master pressure first exits the control master valve 334 and the control master filter 336, as described above. Hydraulic fluid at the control master pressure flows from the filter 336 and is directly fed to each pressure control solenoid valve and each shift solenoid valve. In the ninth range, the first shift solenoid valve 330 is energized and outputs hydraulic fluid at the control master pressure to the first and second shift valves. The control master pressure is also fed to the main modulation solenoid valve 340. Additionally, hydraulic fluid at the control master pressure can also be fed through the third valve portion 2008 and the fourth valve portion 2010 of the third shift valve 350 (where it flows through the check valve 352) and to the head of the second shift valve 348 (i.e., on the top side of the first valve portion 1904). The same fluid flowing to the main modulation solenoid valve 340 and the third shift valve 350 is also fed through the second shift valve 348 and pressurizes the second pressure switch 358. As it proceeds, the fluid under the control of the main pressure is further directed to the fifth fine-tuning system, where it is fed into the opening of the booster plug 328. Here, the fluid flows through the channel 344, separating the booster plug 328 from the fifth fine-tuning valve 326.

[0209] In addition to applying force to C6, force is applied to C2 in a manner similar to that in the seventh and eighth ranges. Hydraulic fluid at the main pressure is fed directly from source 302 to the first shift valve 346. Through the traveling first shift valve 346, fluid can flow to the second shift valve 348. Through the traveling open second shift valve 348, hydraulic fluid can flow to the second fine-tuning system and through the second fine-tuning valve 314 (which is in its traveling position controlled by the second pressure solenoid valve 312). As fluid flows through the second fine-tuning system, it feeds back to the second shift valve 348, where it fills and applies force to C2. The C2 pressure can act on the differential region of the first shift valve 346 and the second shift valve 348 to create a hydraulic interlock on the two valves. Therefore, if power is interrupted in the ninth range and the main control pressure is lost at the heads of both shift valves, the C2 pressure can hydraulically hold the first shift valve 346 and the second shift valve 348 in their traveling positions.

[0210] In the event of a power outage while operating in the ninth range, the control system 300 can be configured to default to the seventh range, as in... Figure 17 As shown in the diagram. Here, the controller cannot supply current to either of the solenoid valves, and therefore, both the first and second shift solenoid valves are de-energized. Once the fifth fine-tuning valve 326 moves to its non-moving position, the normally low pressure control solenoid valves (i.e., solenoid valves 320 and 324) default to zero pressure output, and therefore C6 is vented. When the fourth fine-tuning valve 322 is in its non-moving position, C4 remains vented.

[0211] The constant high-pressure control solenoid valve outputs full pressure to move its corresponding fine-tuning valve to its travel position. In other words, the first fine-tuning valve 310, the second fine-tuning valve 314, and the third fine-tuning valve 318 are positioned in their travel positions. However, C1 cannot be subjected to force because the hydraulic fluid is blocked upstream by the non-traveled third shift valve 350. The latched shift valve 348 also prevents fluid from flowing to the C5 clutch.

[0212] As in Figure 17 As shown, hydraulic fluid at the main pressure flows directly from pressure source 302 to the third fine-tuning system. The fluid can fill and apply force to C3 via the third fine-tuning valve 318 in its travel and open position. The third fine-tuning valve 318 can fine-tune or reduce the hydraulic fluid from the main pressure to pressure C3 to meet the needs of the control system 300. Therefore, as described above, when the system was previously operating in the ninth range, forces are applied to C2 and C3 upon power failure. With forces applied to C2 and C3, the control system 300 thus defaults to the seventh range.

[0213] Another embodiment of this disclosure is shown in Figure 22 In this context, an embodiment of a shift availability table 2200 is described for a multi-speed transmission having at least nine forward gear ranges, neutral, and at least one reverse gear. This table indicates how many torque transmission mechanisms are engaged or disengaged between consecutive ranges. For example, in a first range, C5 and C6 are engaged (as shown above in the table). If a higher gear shift is required in a second range, table 2200 indicates that only one (1) torque transmission mechanism changes between the first and second ranges. As described above, forces are applied to C1 and C5 in the second range. Therefore, C5 is the common torque transmission mechanism and remains engaged during the higher gear shift. Meanwhile, during the higher gear shift, C6 may be unengaged, and C1 may be engaged. Similarly, if the controller wants to skip gears and shift to a higher gear from the first range to the third range, and thus “skip” the second range, the controller can do so by engaging only one new torque transmission mechanism and disengaging one torque transmission mechanism. As described above, forces are applied to C1 and C6 in the third range. Therefore, if a shift from the first range to the third range is to be performed, the controller can do so by controlling the control system 300 to release C5 and apply force to C1. Here, C6 is the common torque transmission mechanism between the first and third ranges. These shifts are desirable because the controller does not need to first transition the control system 300 through neutral before achieving the desired range.

[0214] In another example, the transmission can operate in a fourth range with forces applied to C1 and C4. If the controller wants to shift down to the first range and skip the second and third ranges, shift availability table 2200 indicates that forces will need to be applied to both (2) new torque transmission mechanisms. Furthermore, both C1 and C4 will need to disengage during the downshift. Again, forces are applied to C5 and C6 in the first range. To complete the downshift from the fourth range to the first range, the controller will operatively control the control system 300 such that when forces are applied to C5 and C6, exhausts C1 and C4.

[0215] Furthermore, as described above, the design of the control system 300 allows for the de-energization of the second shift valve 332 to control the third shift valve 350 to its non-operational position, effectively blocking the main feed of fluid to the second fine-tuning system. As a result, C5 cannot be stressed in the third, fourth, or fifth range. However, the logical state of this situation does not negatively affect the skip-shift capability of the control system 300. Moreover, in the seventh, eighth, and ninth ranges, the third shift valve 350 is controlled to its non-operational position, effectively blocking the main feed of hydraulic fluid to the first fine-tuning system. Therefore, C1 cannot be stressed in these higher ranges, thus providing improved fault mode protection for the control system 300, and it is able to do so without affecting the system's skip-shift capability.

[0216] For the purposes of this disclosure, shifting to a higher gear can refer to a gear shift from a lower range to a higher range (e.g., from a first range to a second range), and shifting to a lower gear can refer to a gear shift from a higher range to a lower range (e.g., from a second range to a first range). Skipping gears can include shifting to a higher gear or a lower gear, but when implemented, the control system skips one or more intermediate ranges where the gear shift occurs (e.g., from a fourth range to a first range skipping the second and third ranges). Furthermore, the gear ratio from the input to the output of the transmission can be greater than 1.0 in the lower range, while the gear ratio can be less than 1.0 in the higher range. In one embodiment, one of the ranges may provide a gear ratio equal to or approximately 1.0. In any case, the gear ratio can depend on the transmission architecture, and those skilled in the art will understand the different gear ratios based on different multi-stage transmission architectures. Therefore, this disclosure does not provide any specific gear ratio for any given range.

[0217] While exemplary embodiments incorporating the principles of this disclosure have been disclosed above, this disclosure is not limited to the disclosed embodiments. Instead, this application is intended to cover any changes, uses, or adaptations of this disclosure using its general principles. Furthermore, this application is intended to cover deviations from this disclosure that fall within the scope of known or customary practices in the field to which this disclosure belongs and which are limited by the appended claims.

Claims

1. An electro-hydraulic control system for a multi-stage transmission, comprising: A controller for operatively controlling the multi-stage transmission; A fluid source, used to supply hydraulic fluid; Multiple torque transmission mechanisms are operablely selectable between a stressed state and an unstressed state to achieve multiple ranges including at least one reverse gear range, a neutral gear range, and multiple forward gear ranges, wherein in any of the multiple forward gear ranges, only two of the multiple torque transmission mechanisms are in the stressed state. A plurality of shift valves, each configured to be in fluid communication with the fluid source and to move between a traveling position and a non-traveling position, the plurality of shift valves including at least a first shift valve, a second shift valve and a third shift valve; When operating at a high transmission output speed in the first forward gear range, the first torque transmission mechanism and the second torque transmission mechanism are in their stressed state, while the other torque transmission mechanisms among the plurality of torque transmission mechanisms are in their unstressed state. When the system is immediately de-energized and shifts from the first forward gear range to the neutral gear range, a hydraulic latch is formed by hydraulic fluid abutting against at least one of the first shift valve, the second shift valve, and the third shift valve, such that at least one of the first shift valve, the second shift valve, and the third shift valve is held in the forward position due to the hydraulic latch.

2. The electro-hydraulic control system according to claim 1, further comprising a check valve, the check valve being located between at least one of the first shift valve, the second shift valve and the third shift valve and the discharge passage to form the hydraulic latch.

3. The electro-hydraulic control system of claim 1, wherein, Hydraulic fluid flows from the third shift valve to the second shift valve to form the hydraulic latch and holds the second shift valve in its traveling position after shifting and de-energizing.

4. The electro-hydraulic control system of claim 1, wherein, After the gear shift and the power cut, the electro-hydraulic control system realizes one of the plurality of forward gear ranges, such that the first torque transmission mechanism remains in its stressed state, and one of the other plurality of torque transmission mechanisms is set in its stressed state.

5. The electro-hydraulic control system of claim 1, further comprising a pressure switch configured to be in fluid communication with at least one of the first shift valve, the second shift valve, and the third shift valve and to be in electrical communication with the controller, the pressure switch being configured to detect the position of at least one of the first shift valve, the second shift valve, and the third shift valve.

6. The electro-hydraulic control system of claim 1, wherein, The first torque transmission mechanism remains in its stressed state, and the second torque transmission mechanism is released to its unstressed state during shifting to neutral, such that only the first torque transmission mechanism among the plurality of torque transmission mechanisms is in its stressed state.

7. The electro-hydraulic control system according to claim 1, wherein, The hydraulic latch is formed by a throttling check valve located between at least one of the first shift valve, the second shift valve, and the third shift valve and the discharge passage.

8. The electro-hydraulic control system according to claim 1, further comprising at least one fine-tuning system, said at least one fine-tuning system being electrically connected to the controller and fluidly connected to the fluid source, wherein, The at least one fine-tuning system includes a pressure-controlled solenoid valve and a fine-tuning valve.

9. An electro-hydraulic control system for a multi-stage transmission, comprising: A controller for operatively controlling the multi-stage transmission; A fluid source, used to supply hydraulic fluid; Multiple torque transmission mechanisms are operablely selectable between a stressed state and an unstressed state to achieve multiple ranges including at least one reverse gear range, a neutral gear range, and multiple forward gear ranges, wherein in any of the multiple forward gear ranges, only two of the multiple torque transmission mechanisms are in the stressed state. Multiple fine-tuning systems electrically connected to the controller and fluidly connected to the fluid source, wherein each of the multiple fine-tuning systems includes a pressure-controlled solenoid valve and a fine-tuning valve; A plurality of shift valves, each configured to be in fluid communication with the fluid source and to move between a traveling position and a non-traveling position, the plurality of shift valves including at least a first shift valve, a second shift valve and a third shift valve; A pressure-boosting plug is configured to be in direct fluid communication with a first torque transmission mechanism in the plurality of torque transmission mechanisms, a first fine-tuning system in the plurality of fine-tuning systems, and a second shift valve. The first fine-tuning system includes a first pressure control solenoid valve and a first fine-tuning valve. in, In at least one of the plurality of forward gear ranges, hydraulic fluid from the fluid source does not fluidly connect the booster plug to the second shift valve, and the first pressure control solenoid valve pressurizes the booster plug and the first fine-tuning valve to the travel position. In another forward gear range among the plurality of forward gear ranges, hydraulic fluid from the fluid source fluidly connects the booster plug to the second shift valve, and the hydraulic fluid bypasses the booster plug such that only the first fine-tuning valve moves to the travel position.

10. The electro-hydraulic control system according to claim 9, wherein, For any given output of the first pressure control solenoid valve, the movement of the booster plug operably controls the clutch pressure of the first torque transmission mechanism.

11. The electro-hydraulic control system according to claim 10, wherein, When the booster plug and the first fine-tuning valve move to the traveling position, the clutch pressure of the first torque transmission mechanism is less than the clutch pressure of the first torque transmission mechanism when only the first fine-tuning valve moves to the traveling position.

12. The electro-hydraulic control system according to claim 9, wherein, Within two of the plurality of forward gear ranges, hydraulic fluid from the fluid source does not fluidly connect the booster plug to the second shift valve, and the first pressure control solenoid valve pressurizes the booster plug to move it to its travel position together with the first fine-tuning valve.

13. The electro-hydraulic control system according to claim 9, wherein, At least three of the multiple pressure control solenoid valves in the plurality of fine-tuning systems include normally high solenoid valves, and the remaining pressure control solenoid valves in the plurality of fine-tuning systems include normally low solenoid valves.

14. The electro-hydraulic control system according to claim 9, further comprising a plurality of shift solenoid valves disclosed to be electrically connected to the controller and operablely controllable between an energized state and an de-energized state, the plurality of shift solenoid valves including at least a first shift solenoid valve and a second shift solenoid valve. in, The first shift solenoid valve is configured to control the first shift valve and the second shift valve, and the second shift solenoid valve is configured to control the third shift valve.

15. An electro-hydraulic control system for a multi-stage transmission, comprising: A controller for operatively controlling the multi-stage transmission; A fluid source, which supplies hydraulic fluid at primary pressure; Multiple torque transmission mechanisms are operablely selectable between a stressed state and an unstressed state to achieve multiple ranges; A fine-tuning system electrically connected to the controller and fluidly connected to the fluid source, wherein the fine-tuning system includes a pressure-controlled solenoid valve and a fine-tuning valve; A plurality of shift valves, each configured to be in fluid communication with the fluid source and to move between a traveling position and a non-traveling position, the plurality of shift valves including at least a first shift valve, a second shift valve and a third shift valve; A booster valve is configured to be in fluid communication with at least two of the fine-tuning system, the second shift valve, and the plurality of torque transmission mechanisms, wherein the booster valve is hydraulically controlled between a first position and a second position; When one of the at least two torque transmission mechanisms is under stress, the fluid pressure exerted on one of the torque transmission mechanisms is lower than the main pressure and the pressure booster valve is hydraulically held in its first position.

16. The electro-hydraulic control system according to claim 15, wherein, When the booster valve is in the first position, one of the at least two torque transmission mechanisms configured to be in fluid communication with the booster valve is in a stressed state, preventing the booster valve from moving to its second position. When the booster valve is in the second position, the second torque transmission mechanism, which is in fluid communication with the booster valve, is under force, such that the hydraulic fluid used to apply force to the second torque transmission mechanism among the at least two torque transmission mechanisms hydraulically moves the booster valve to its second position.

17. The electro-hydraulic control system according to claim 15, further comprising a plurality of shift solenoid valves, each shift solenoid valve being configured to be electrically connected to the controller and operablely controllable between an energized state and an de-energized state, the plurality of shift solenoid valves comprising at least a first shift solenoid valve and a second shift solenoid valve. in, The first shift solenoid valve is configured to control the first shift valve and the second shift valve, and the second shift solenoid valve is configured to control the third shift valve.

18. The electro-hydraulic control system according to claim 17, wherein, The multiple ranges include at least one reverse gear range, a neutral gear range, and at least one forward gear range, wherein only two of the multiple torque transmission mechanisms are under stress in the at least one forward gear range; At least three of the multiple pressure control solenoid valves in the multiple fine-tuning systems include normally high solenoid valves, and the remaining pressure control solenoid valves include normally low solenoid valves. When operating in at least one reverse or neutral gear range and with electrical communication between the controller and each of the pressure control solenoid valve and the shift solenoid valve disabled, the normally high solenoid valve outputs full pressure, the normally low solenoid valve does not output pressure, and the first and second shift solenoid valves do not output pressure, such that only one of the plurality of torque transmission mechanisms is under stress, and the torque transmission mechanism in the unstressed state is not in fluid communication with the fluid source.

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