Transmission control system

Patent metadata

Field	Value
Publication number	US-9346456-B2
Application number	US-201414186072-A
Country	US
Kind code	B2
Filing date	Feb 21, 2014
Priority date	Mar 5, 2013
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

A transmission control system can include a main transmission. The transmission control system can also include a sub transmission that has two forward transmission gears mechanically shiftable in response to a shift operation. The transmission control system can further include a controller that shifts the transmission gears of the main transmission by activating a shift control motor, and control the clutches configured to enable and disable transmission of a rotational driving force of an engine. When one forward transmission gear of the sub transmission is shifted to the other forward transmission gear in response to the shift operation, the controller can relax engagement of the clutch if an engine speed exceeds a clutch release speed.

First claim

I claim:

1. A transmission control system, comprising:
a main transmission to which a rotational driving force of an engine is transmitted via a clutch, the main transmission having a plurality of transmission gears;
a sub transmission having at least two forward transmission gears mechanically shiftable in response to a shift operation; and
a controller configured to shift the transmission gears of the main transmission by activating an actuator, the controller also configured to control the clutch configured to enable and disable transmission of the rotational driving force of the engine,
wherein when one of the forward transmission gears of the sub transmission is shifted to another one of the forward transmission gears in response to the shift operation, the controller is configured to relax engagement of the clutch if an engine speed exceeds a clutch release speed,
wherein the controller is configured to stop fuel injection to a cylinder of the engine when the engine speed exceeds a revolution limit speed, and stop ignition in the cylinder of the engine when the engine speed exceeds an upper limit speed, and
wherein the clutch release speed, the revolution limit speed, and the upper limit speed satisfy a relationship of revolution limit speed<clutch release speed<upper limit speed.

2. The transmission control system according to claim 1 , wherein the controller is configured to release the clutch regardless of the engine speed when another shift operation other than the operation to shift one of the forward transmission gears of the sub transmission to another one of the forward transmission gears is performed.

3. The transmission control system according to claim 1 , wherein when one of the forward transmission gears of the sub transmission is shifted to another one of the forward transmission gears in response to the shift operation, the controller is configured to set a clutch capacity of the clutch to zero if the engine speed exceeds the clutch release speed, and then increase the clutch capacity along with a reduction of the engine speed.

4. A transmission control system, comprising:
a transmitting means for transmitting rotational driving force of an engine via a power transmitting means, the transmitting means having a plurality of transmission gears;
a gear shifting means for performing gear shifting having at least two forward transmission gears mechanically shiftable in response to a shift operation; and
a controlling means for controlling shifting of the transmission gears of the transmitting means by activating an actuating means, the controlling means configured to control the power transmitting means configured to enable and disable transmission of the rotational driving force of the engine,
wherein when one of the forward transmission gears of the gear shifting means is shifted to another one of the forward transmission gears in response to the shift operation, the controlling means is configured to relax engagement of the power transmitting means if an engine speed exceeds a clutch release speed,
wherein the controlling means is configured to stop fuel injection to a reciprocating means of the engine when the engine speed exceeds a revolution limit speed, and stop ignition in the reciprocating means of the engine when the engine speed exceeds an upper limit speed, and
wherein the clutch release speed, the revolution limit speed, and the upper limit speed satisfy a relationship of revolution limit speed<clutch release speed<upper limit speed.

5. The transmission control system according to claim 4 , wherein the controlling means is configured to release the power transmitting means regardless of the engine speed when another shift operation other than the operation to shift one of the forward transmission gears of the gear shifting means to another one of the forward transmission gears is performed.

6. The transmission control system according to claim 4 , wherein when one of the forward transmission gears of the gear shifting means is shifted to another one of the forward transmission gears in response to the shift operation, the controlling means is configured to set a clutch capacity of the power transmitting means to zero if the engine speed exceeds the clutch release speed, and then increase the clutch capacity along with a reduction of the engine speed.

7. A method of controlling a transmission control system, the method comprising:
transmitting rotational driving force of an engine via a clutch to a main transmission, the main transmission having a plurality of transmission gears;
performing gear shifting with a sub transmission having at least two forward transmission gears mechanically shiftable in response to a shift operation;
controlling shifting of the transmission gears of the main transmission with a controller by activating an actuator, the controller also configured to control the clutch configured to enable and disable transmission of the rotational driving force of the engine,
wherein when one of the forward transmission gears of the sub transmission is shifted to another one of the forward transmission gears in response to the shift operation, the controller is configured to relax engagement of the clutch if an engine speed exceeds a clutch release speed,
wherein the controller is configured to stop fuel injection to a cylinder of the engine when the engine speed exceeds a revolution limit speed, and stop ignition in the cylinder of the engine when the engine speed exceeds an upper limit speed, and
wherein the clutch release speed, the revolution limit speed, and the upper limit speed satisfy a relationship of revolution limit speed<clutch release speed<upper limit speed.

8. The method according to claim 7 , wherein the controller is configured to release the clutch regardless of the engine speed when another shift operation other than the operation to shift one of the forward transmission gears of the sub transmission to another one of the forward transmission gears is performed.

9. The method according to claim 7 , wherein when one of the forward transmission gears of the sub transmission is shifted to another one of the forward transmission gears in response to the shift operation, the controller is configured to set a clutch capacity of the clutch to zero if the engine speed exceeds the clutch release speed, and then increase the clutch capacity along with a reduction of the engine speed.

Assignees

• Honda Motor Co Ltd

Inventors

• Sakamoto Naoki

Classifications

• B60W10/06

  including control of combustion engines · CPC title

• F16H61/12

  Detecting malfunction or potential malfunction, e.g. fail safe (in control of hydrostatic gearing F16H61/4192) {; Circumventing or fixing failures} · CPC title

• F16H2059/366

  Engine or motor speed · CPC title

• F16H63/502

  for smoothing gear shifts · CPC title

• B60W10/02

  including control of driveline clutches · CPC title