Hydraulic control system of automated manual transmission

• US 20020148310A1
• Filed: 04/15/2002
• Published: 10/17/2002
• Est. Priority Date: 04/16/2001
• Status: Active Grant

• Current Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Original Assignee: Fuji Heavy Industries Limited (Subaru Corp.)
• Inventors: Uchino, Satoshi
• Granted Patent: US 6,865,965 B2
• Time in Patent Office: Days
• US Class Current: 74/335
• CPC Class Codes: F16H 2045/005 comprising a clutch between fluid gearing and the mechanical gearing unit
• CPC Class Codes: F16H 2059/006 Overriding automatic control
• CPC Class Codes: F16H 2061/1232 Bringing the control into a predefined state, e.g. giving priority to particular actuators or gear ratios
• CPC Class Codes: F16H 2061/124 Limiting the input power, torque or speed
• CPC Class Codes: F16H 2061/1244 Keeping the current state
• CPC Class Codes: F16H 2061/1268 Electric parts of the controller, e.g. a defect solenoid, wiring or microprocessor
• CPC Class Codes: F16H 2306/00 Shifting
• CPC Class Codes: F16H 61/12 Detecting malfunction or potential malfunction, e.g. fail safe in control of hydrostatic gearing F16H61/4192; Circumventing or fixing failures
• CPC Class Codes: F16H 61/2807 using electric control signals for shift actuators, e.g. electro-hydraulic control therefor F16H61/30, F16H61/32 take precedence; methods for generating shift signals F16H61/0213
• CPC Class Codes: F16H 61/682 with interruption of drive
• CPC Class Codes: Y10S 477/906 Means detecting or ameliorating the effects of malfunction or potential malfunction
• CPC Class Codes: Y10T 74/19251 Control mechanism

Abstract

An automated manual transmission has an input shaft having a plurality of driving gears, and an output shaft having a plurality of driven gears engaging with the driving gears, and further has two bypass clutches for coupling the input shaft and the output shaft with each other and releasing them from coupling. Electromagnetic valves are provided in hydraulic oil paths for guiding hydraulic pressure from a hydraulic pressure supply portion to the bypass clutches respectively. A bypass oil path for bypassing the hydraulic oil paths is provided with a bypass oil path on-off valve for opening the bypass oil path when the electromagnetic valves cannot be operated due to a failure of an electric system. A bypass oil path change-over valve is provided for changing over to supply hydraulic pressure from the bypass oil path on-off valve to one of the bypass clutches.

Claims

1. A hydraulic control system of an automated manual transmission comprising:

an input shaft having a plurality of driving gears;

an output shaft having a plurality of driven gears engaging with the driving gears;

a shift actuator shifting a change gear array for transmitting power from the input shaft to the output shaft;

a plurality of bypass clutches for carrying out coupling and uncoupling between the input shaft and the output shaft respectively;

a plurality of electromagnetic valves provided in a plurality of hydraulic oil paths which guide hydraulic pressure from a hydraulic pressure supply portion to the respective bypass clutches, for opening and closing the corresponding hydraulic oil paths respectively; and

a bypass oil path on-off valve provided in a bypass oil path which bypasses the respective hydraulic oil paths, for opening the bypass oil path when the electromagnetic valves cannot be operated due to a failure in an electric system.

2. The hydraulic control system of an automated manual transmission as set forth in claim 1, further comprising:

a bypass oil path change-over valve adapted to be changed over to supply hydraulic pressure from the bypass oil path on-off valve to the plurality of bypass clutches.

3. The hydraulic control system of an automated manual transmission as set forth in claim 2, wherein the bypass oil path change-over valve changes over to a position to supply hydraulic pressure to one of the bypass clutches on a failure occasion of the electric system, while the bypass oil path change-over valve is brought into a switching mode using hydraulic pressure from the hydraulic oil path as pilot pressure when hydraulic pressure from the hydraulic oil path is supplied to another one of the bypass clutches on a normal occasion of the electric system, and

the switching mode is maintained also on a failure occasion of the electric system.

4. The hydraulic control system of an automated manual transmission as set forth in claim 2, further comprising:

a fail safe valve for changing over between discharge of pilot pressure and suspension of the discharge in accordance with a normal occasion and a failure occasion of an electric system;

a reverse servo valve for discharging hydraulic pressure when a reverse range is selected by operation of a select lever; and

a fail mode valve for actuating the bypass oil path change-over valve so as to supply hydraulic pressure to a specific one of the bypass clutches when the fail safe valve detects a failure occasion of the electric system while hydraulic pressure is supplied from the reverse servo valve.

5. The hydraulic control system of an automated manual transmission as set forth in claim 4, wherein the fail mode valve supplies hydraulic pressure to the bypass oil path change-over valve when an engine is suspended while there occurs a failure in the electric system.

6. A hydraulic control system of an automated manual transmission comprising:

an input shaft having a plurality of driving gears;

an output shaft having a plurality of driven gears engaging with the driving gears;

a shift actuator shifting a change gear array for transmitting power from the input shaft to the output shaft;

a bypass clutch for carrying out coupling and uncoupling between the input shaft and the output shaft;

a reverse servo valve for switching the automated manual transmission to one of a forward stage and a reverse stage in accordance with operation of a select lever, the reverse servo valve supplying hydraulic pressure when the automated manual transmission is switched to the reverse stage; and

a fail mode valve for supplying hydraulic pressure to the shift actuator so as to set the shift actuator in a neutral position when hydraulic pressure is supplied from the reverse servo valve on an occasion of a failure in an electric system;

wherein the hydraulic pressure is supplied from the reverse servo valve to the bypass clutch.

7. A hydraulic control system of an automated manual transmission comprising:

an input shaft having a plurality of driving gears;

an output shaft having a plurality of driven gears engaging with the driving gears;

a shift actuator shifted a change gear array for transmitting power from the input shaft to the output shaft;

an input clutch for carrying out coupling and uncoupling between an engine and the input shaft;

a bypass clutch for carrying out coupling and uncoupling between the input shaft and the output shaft;

a reverse servo valve for switching the automated manual transmission to one of a forward stage and a reverse stage in accordance with operation of a select lever, the reverse servo valve supplying hydraulic pressure when the automated manual transmission is switched to the reverse stage;

a fail mode valve for supplying hydraulic pressure to the shift actuator so as to set the shift actuator in a neutral position when hydraulic pressure is supplied from the reverse servo valve on an occasion of a failure in an electric system; and

a neutral position detecting valve for supplying hydraulic pressure for coupling to the input clutch when the shift actuator takes the neutral position;

wherein the hydraulic pressure supplied from the neutral position detecting valve is supplied to the input clutch, while the hydraulic pressure supplied from the reverse servo valve is supplied to the bypass clutch.

8. A hydraulic control system of an automated manual transmission comprising:

an input shaft having a plurality of driving gears;

an output shaft having a plurality of driven gears engaging with the driving gears;

an input clutch for carrying out coupling and uncoupling between an engine and the output shaft;

a plurality of shift actuators for shifting a change gear array for transmitting power from the input shaft to the output shaft;

a fail mode valve for supplying hydraulic pressure to the shift actuators so that the shift actuators take neutral positions on a failure occasion of an electric system; and

neutral position detecting valves for supplying hydraulic pressure from a hydraulic pressure supply portion to the input clutch when the shift actuators take the neutral positions;

wherein the hydraulic pressure is supplied to the input clutch through the neutral position detecting valves.

9. The hydraulic control system of an automated manual transmission as set forth in claim 8, wherein a fail safe valve for the input clutch is provided in an oil path for supplying hydraulic pressure to the input clutch on a normal occasion of electric system, the fail safe valve blocking the oil path in accordance with hydraulic pressure from the fail mode valve on the failure occasion of the electric system.