# US 2001/0027147 A1 · Control device of continuously variable transmission

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- Number: US 2001/0027147 A1
- Document ID: US20010027147A1
- Status: Published application
- Kind: A1
- Application number: 09/810,608
- Filed: 2001-03-20
- Published: 2001-10-04
- Earliest claimed: 2000-03-21
- Assignees: Jatco Transtechnology Ltd.
- Inventors: Yoshihide Shinso; Yoshikazu Miyagawa; Satoshi Sakakibara
- Web page: https://patentgrep.com/patent/US20010027147A1

## CPC

- B60W 20/00: Control systems specially adapted for hybrid vehicles {(hybrid vehicle design, B60K6/00; electric vehicles B60L)}
- B60K 6/36: characterised by the transmission gearings
- B60K 6/543: the transmission being a continuously variable transmission
- B60W 10/08: including control of electric propulsion units, e.g. motors or generators
- B60W 10/10: including control of change-speed gearings
- B60W 10/30: including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
- F16H 61/12: Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures}
- B60W 2050/021: {Means for detecting failure or malfunction}
- F16H 61/662: with endless flexible members
- F16H 2061/1248: {Resuming normal operation}
- F16H 2061/1292: {the failing part is the power supply, e.g. the electric power supply}
- F16H 2312/02: Driving off
- F16H 2312/20: Start-up or shut-down
- Y10S 903/903: having energy storing means, e.g. battery, capacitor
- Y10S 903/918: Continuously variable
- Y10S 903/945: Characterized by control of gearing, e.g. control of transmission ratio
- B60W: CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- F16H: GEARING
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

A transmission mechanism of continuously variable transmission in a vehicle comprises a primary pulley and a secondary pulley provided with a first cylinder chamber and a second cylinder chamber, with groove widths being changed by supply of hydraulic pressure, and a belt provided between the pulleys. A hydraulic pressure to the first cylinder chamber is controlled by CVT control unit through a shift control valve according to a driving state of the vehicle, and the second cylinder chamber is continuously supplied with a line pressure. CVT control unit includes an internal memory to retain a heavy-current system fail flag according to the failure information inputted from a motor control unit. If, at start of driving, the internal memory holds failure information indicating that the electric motor driving a hydraulic pump fails in previous driving, CVT control unit outputs a shift command targeting a high range ratio for a predetermined time to thereby fill the first cylinder chamber with hydraulic pressure, and thereafter outputs a shift command targeting a normal gear ratio according to the driving state.

## Claims

### Claim 1

A control device of a continuously variable transmission which comprises: a transmission mechanism comprising a pair of variable pulleys with groove widths being changed by supply of hydraulic pressure, and a belt provided between said pair of variable pulleys; a hydraulic pump being driven by an electric motor to supply hydraulic pressure; line pressure control means for regulating hydraulic pressure from said hydraulic pump to predetermined line pressure; shift control means for outputting a shift command according to a driving state; and a shift control valve for supplying hydraulic pressure, whose original pressure is line pressure, to said pair of variable pulleys in said transmission mechanism according to said shift command; said control device of the continuously variable transmission comprising:
failure information holding means for holding failure information on a failure of said electric motor; and
wherein if, at start of driving, said failure information holding means holds failure information indicating that said electric motor fails in previous driving, said shift control means outputs a predetermined shift command to thereby fill said variable pulleys with hydraulic pressure through said shift control valve.

### Claim 2

A control device of a continuously variable transmission, which comprises: a transmission mechanism comprising a primary pulley and a secondary pulley provided with a first cylinder chamber and a second cylinder chamber, with groove widths being changed by supply of hydraulic pressure respectively, and a belt provided between said primary pulley and said secondary pulley; a hydraulic pump being driven by an electric motor to supply hydraulic pressure; line pressure control means, for regulating hydraulic pressure from said hydraulic pump to predetermined line pressure and continuously supplying said line pressure to second cylinder chamber; a shift control valve being driven by an actuator to supply hydraulic pressure, whose original pressure is line pressure, to said first cylinder chamber; and shift control means for outputting a shift command for controlling said actuator according to a driving state, said control device of the continuously variable transmission comprising:
failure information holding means for holding failure information on a failure of said electric motor; and
wherein if, at start of driving, said failure information holding means holds failure information indicating that said electric motor fails in previous driving, said shift control means outputs a shift command targeting a high range ratio to thereby fill said first cylinder chamber of said primary pulley with hydraulic pressure.

### Claim 3 (depends on 2)

A control device of a continuously variable transmission according to claim 2, wherein said first cylinder chamber is filled with hydraulic pressure by holding a shift command targeting said high range ratio for a predetermined period of time.

### Claim 4

A control device of a continuously variable transmission in a vehicle, which control device comprises: a transmission mechanism comprising a primary pulley and a secondary pulley provided with a first cylinder chamber and a second cylinder chamber, with groove widths being changed by supply of hydraulic pressure respectively, and a belt provided between said primary pulley and said secondary pulley; a hydraulic pump being driven by an electric motor to supply hydraulic pressure; line pressure control means for regulating hydraulic pressure from said hydraulic pump to predetermined line pressure and continuously supplying said line pressure to said second cylinder chamber; a shift control valve being driven by an actuator to supply hydraulic pressure, whose original pressure is line pressure, to said first cylinder chamber; and shift control means for outputting a shift command for controlling said actuator according to a driving state, said control device of the continuously variable transmission comprising:
failure information holding means for holding failure information concerning a failure of said electric motor; and
wherein if, at start of driving, said failure information holding means holds failure information indicating that said electric motor fails in previous driving, said shift control means outputs a shift command targeting a high range ratio for a predetermined period of time before the start of driving to thereby fill said first cylinder chamber of said primary pulley with hydraulic pressure, and starts outputting a shift command targeting a normal gear ratio according to the driving state after a predetermined vehicle speed is reached after the start of driving.

### Claim 5 (depends on 4)

A control device of a continuously variable transmission according to claim 4, wherein:
a motor control unit controls said electric motor;
said failure information holding means is an internal memory of said shift control means, said internal memory retaining a heavy-current system fail flag according to the failure information inputted from said motor control unit;
and said heavy-current system fail flag is reset after said predetermined vehicle speed is reached.