Transmission control method for continuously variable transmission

• US 8,447,480 B2
• Filed: 01/28/2009
• Issued: 05/21/2013
• Est. Priority Date: 01/31/2008
• Status: Expired due to Fees

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Usukura, Yasutaka
• Primary Examiner(s): Black, Thomas
• Assistant Examiner(s): LOUIE, WAE LENNY
• Application Number:
  US12/361,171
• Publication Number:
  US 20090197735A1
• Time in Patent Office: 1,574 Days
• Field of Search: 701/55, 701/51, 701/53, 477/43, 477/3, 477/34, 477/37
• US Class Current: 701/55
• CPC Class Codes: B62M 19/00 Transmissions characterised by use of non-mechanical gearing, e.g. fluid gearing
• CPC Class Codes: F16H 2059/0221 for selecting modes, i.e. input device for selecting between different modes with range selector F16H2059/082; for conjoint control B60W30/182
• CPC Class Codes: F16H 2059/6853 the state of the transmission units, i.e. motor or pump capacity, e.g. for controlled shifting of range gear
• CPC Class Codes: F16H 59/24 dependent on the throttle opening
• CPC Class Codes: F16H 59/42 Input shaft speed
• CPC Class Codes: F16H 59/44 dependent on machine speed of the machine, e.g. the vehicle
• CPC Class Codes: F16H 61/425 Motor capacity control by electric actuators
• CPC Class Codes: F16H 61/462 for achieving a target speed ratio
• CPC Class Codes: F16H 61/465 for achieving a target input speed

Abstract

A transmission control method for a continuously variable transmission for enhancing the response of a change in engine speed to a driver'"'"'s accelerating/decelerating operation. In a hydraulic type continuously variable transmission, when a sport operating mode is being selected (step S1: SPORT OPERATING MODE), a target engine speed T_NE (rpm) is calculated from the vehicle velocity V (km/hr) and the position θ (degrees) of a throttle valve 60 (step S4). Further, a target angle T_A (degrees) for a motor swash plate is calculated from the vehicle velocity and the target engine speed T_NE (step S5). The motor swash plate is moved according to the difference between the actual angle A of the motor swash plate 46 and the target angle T_A.

Claims

1. A transmission control method for a swash plate, hydraulic type continuously variable transmission having a plurality of transmission control modes comprising the following steps:

wherein in a first transmission control mode,

lowering an actual transmission gear ratio when a target engine speed calculated from vehicle velocity and throttle position is higher than an actual engine speed, and

raising said actual transmission gear ratio when said target engine speed is lower than said actual engine speed; and

in a second transmission control mode,

calculating a target transmission gear ratio based on said target engine speed, which is calculated from said vehicle velocity and said throttle position,

changing said actual transmission gear ratio toward said calculated target transmission gear ratio,

said actual transmission gear ratio being changed by hydraulic pressure on a transmission movable member of the continuously variable transmission, and

said transmission movable member is a motor swash plate or a movable member of a transmission actuator for controlling the angle of said motor swash plate.

2. The transmission control method for the continuously variable transmission as set forth in claim 1,

wherein in said second transmission control mode,

calculating said target transmission gear ratio as a function of said target engine speed and said vehicle velocity,

calculating a target position for said transmission movable member correspondingly to said calculated target transmission gear ratio, and

changing the actual position of said transmission movable member toward said calculated target position.

3. The transmission control method for the continuously variable transmission as set forth in claim 1, wherein the continuously variable transmission is controlled by an electrical control unit through the transmission actuator.

4. The transmission control method for the continuously variable transmission as set forth in claim 3, wherein the electronic control unit produces a control signal in accordance with engine speed detected by an engine speed sensor, a position of a throttle valve according to an operation of a throttle grip detected by a throttle position sensor and a vehicle velocity detected by a vehicle velocity sensor, said control signal controls the transmission actuator.

5. The transmission control method for the continuously variable transmission as set forth in claim 4, wherein said transmission actuator is operatively connected to the swash plate,

wherein the angle of the swash plate is controlled by the movement of the transmission actuator.

6. The transmission control method for the continuously variable transmission as set forth in claim 1, wherein the target transmission gear ratio is calculated by the formula:

T_—

R=(T_—

NE/V)×

Ro×

0.06

wherein;

T_NE is the target engine speed,

V is the vehicle velocity,

Ro is the reduction gear ratio of the other transmission gear, and

0.06 is a coefficient for unit matching.

7. The transmission control method for the continuously variable transmission as set forth in claim 5, wherein the angle of the swash plate is calculated by the electrical control unit according to position information of a movable part of the transmission actuator.

8. The transmission control method for the continuously variable transmission as set forth in claim 5, wherein the angle of the swash plate is calculated by an angle sensor.

9. A transmission control method for a swash plate, hydraulic type continuously variable transmission comprising the following steps:

calculating a target transmission gear ratio from a target engine speed, which is calculated from vehicle velocity and throttle position, and said vehicle velocity, and

changing an actual transmission gear ratio toward said calculated target transmission gear ratio,

said actual transmission gear ratio being changed by hydraulic pressure on a transmission movable member of the continuously variable transmission, and

said transmission movable member is a motor swash plate or a movable member of a transmission actuator for controlling the angle of said motor swashplate.

10. The transmission control method for the continuously variable transmission as set forth in claim 9, wherein the continuously variable transmission is controlled by an electrical control unit through the transmission actuator.

11. The transmission control method for the continuously variable transmission as set forth in claim 10, wherein the electronic control unit produces a control signal in accordance with engine speed detected by an engine speed sensor, a position of a throttle valve according to an operation of a throttle grip detected by a throttle position sensor and a vehicle velocity detected by a vehicle velocity sensor, said control signal controls the transmission actuator.

12. A transmission control method for a hydraulic type continuously variable transmission having a plurality of transmission control modes comprising the following steps:

wherein in a first transmission control mode,

calculating a target engine speed from a vehicle velocity and throttle position;

lowering an actual transmission gear ratio when the target engine speed is higher than an actual engine speed, and

raising said actual transmission gear ratio when said target engine speed is lower than said actual engine speed; and

in a second transmission control mode,

calculating a target transmission gear ratio based on said target engine speed and said vehicle velocity, and

changing said actual transmission gear ratio toward said calculated target transmission gear ratio,

said actual transmission gear ratio being changed by hydraulic pressure on a transmission movable member of the continuously variable transmission

wherein the continuously variable transmission is controlled by an electrical control unit through a transmission actuator,

the electronic control unit produces a control signal in accordance with engine speed detected by an engine speed sensor, a position of a throttle valve according to an operation of a throttle grip detected by a throttle position sensor and a vehicle velocity detected by a vehicle velocity sensor, and

the control signal controls the transmission actuator.

13. The transmission control method for the continuously variable transmission as set forth in claim 12,

wherein in said second transmission control mode,

calculating said target transmission gear ratio as a function of said target engine speed and said vehicle velocity,

calculating a target position for said transmission movable member correspondingly to said calculated target transmission gear ratio, and

changing the actual position of said transmission movable member toward said calculated target position.

14. The transmission control method for the continuously variable transmission as set forth in claim 13,

wherein said continuously variable transmission is a swash plate, hydraulic type continuously variable transmission, and

said transmission movable member is a motor swash plate or a movable member of the transmission actuator for controlling the angle of said motor swash plate.

15. The transmission control method for the continuously variable transmission as set forth in claim 12, wherein said transmission actuator is operatively connected to a swash plate wherein the angle of the swash plate is controlled by the movement of the transmission actuator.

16. The transmission control method for the continuously variable transmission as set forth in claim 15, wherein the angle of the swash plate is calculated by the electrical control unit according to position information of a movable part of the transmission actuator.

17. The transmission control method for the continuously variable transmission as set forth in claim 15, wherein the angle of the swash plate is calculated by an angle sensor.

18. The transmission control method for the continuously variable transmission as set forth in claim 12, wherein the target transmission gear ratio is calculated by the formula:

T_—

R=(T_—

NE/V)×

Ro×

0.06

wherein;

T_NE is the target engine speed,

V is the vehicle velocity,

Ro is the reduction gear ratio of the other transmission gear, and

0.06 is a coefficient for unit matching.