Control system for vehicle

Patent metadata

Field	Value
Publication number	US-9783192-B2
Application number	US-201515305561-A
Country	US
Kind code	B2
Filing date	Apr 22, 2015
Priority date	Apr 25, 2014
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A control system, for a vehicle (Ve), comprises an electronic control unit ( 18 ) and a selectable one-way clutch ( 17 ). The electronic control unit ( 18 ) is configured to produce differential rotation in the selectable one-way clutch ( 17 ) by controlling the rotational speed by a motor ( 2 ), the differential rotation including positive differential rotation and negative differential rotation, the positive differential rotation being the relative rotation in a direction in which the relative rotation is restricted in an engaged state of the selectable one-way clutch ( 17 ), and the negative differential rotation being the relative rotation in a direction in which the relative rotation is permitted in an engaged state of the selectable one-way clutch ( 17 ), wherein the electronic control unit (1.) sets a first state of the selectable one-way clutch ( 17 ), and (2.) executes lock rotation control in which the differential rotation is maintained at positive differential rotation, in the case where the control unit ( 18 ) switches the selectable one-way clutch ( 17 ) from the disengaged state to the engaged state.

First claim

The invention claimed is:

1. A control system for a vehicle,
the control system comprising:
a selectable one-way clutch including a first clutch member, a second clutch member, a strut, and a switching mechanism,
the first clutch member and the second clutch member configured to rotate relatively to each other,
at least a part of the strut configured to be operated such that the part of the strut is projected from a first clutch member side to a second clutch member side,
the switching mechanism configured to selectively set a first state and a second state, the first state being a state that the switching mechanism permits a projection of the strut to the second clutch member side, and the second state being a state that the switching mechanism inhibits the projection of the strut,
the selectable one-way clutch configured to be switched between an engaged state and a disengaged state, the engaged state being a state that restricts a relative rotation in either a positive rotational direction or a reverse rotational direction in the first state with engaging the part of the strut with a part of the second clutch member, and the disengaged state being a state that permits the relative rotation in both of the positive rotational direction and the reverse rotational direction in the second state without projecting the strut to the second clutch member side;

a motor configured to control a rotational speed of either a first rotary member or a second rotary member; and
an electronic control unit configured to
(i) produce differential rotation by controlling the rotational speed by the motor, the differential rotation including positive differential rotation and negative differential rotation, the positive differential rotation being the relative rotation in a direction in which the relative rotation is restricted in the engaged state, and the negative differential rotation being the relative rotation in a direction in which the relative rotation is permitted in the engaged state, and
(ii) (1) set the first state, and (2) execute lock rotation control in which the differential rotation is maintained at a specified positive value of the positive differential rotation, when the electronic control unit switches the selectable one-way clutch from the disengaged state to the engaged state.

2. The control system according to claim 1 , wherein
the selectable one-way clutch has a ratchet mechanism,
the ratchet mechanism is configured such that the part of the strut, which is projected to the second clutch member side, is operated so as not to be engaged with the part of the second clutch member when a differential rotation speed is equal to or higher than a first differential rotation speed on a positive side,
the ratchet mechanism is configured such that the part of the strut is operated so as to be engaged with the part of the second clutch member when the differential rotation speed is lower than the first differential rotation speed,
a first target differential rotation speed is set as a target value of the differential rotation speed for maintaining the differential rotation speed to be positive in the lock rotation control, and
the first target differential rotation speed is set as a value that is lower than the first differential rotation speed.

3. The control system according to claim 1 , wherein
the electronic control unit is configured to (i) set the first state and execute unlock rotation control in which a differential rotation speed is once maintained to be negative, and (ii) then execute the lock rotation control, when the selectable one-way clutch is switched from the disengaged state to the engaged state.

4. The control system according to claim 3 , wherein
a second target differential rotation speed is set as a target value of the differential rotation speed for once maintaining the differential rotation speed to be negative in the unlock rotation control, and
the electronic control unit is configured to control the motor such that the speed of the differential rotation is maintained at the second target differential rotation speed until the first state is set and the part of the strut is projected to the second clutch member side.

5. The control system according to claim 1 , wherein
a second differential rotation speed is set as a threshold on a positive side for maintaining the differential rotation speed to be positive in the lock rotation control, and
the electronic control unit is configured to execute unlock rotation control in which the differential rotation speed is once maintained to be negative and then execute the lock rotation control again, when the differential rotation speed becomes equal to or higher than the second differential rotation speed during execution of the lock rotation control.

6. The control system according to claim 1 , wherein
a second differential rotation speed is set as a threshold on a positive side for maintaining the differential rotation speed to be positive in the lock rotation control, and
the electronic control unit is configured to reduce the differential rotation speed once and then execute the lock rotation control again, when the differential rotation speed becomes equal to or higher than the second differential rotation speed during execution of the lock rotation control.

7. The control system according to claim 1 , wherein
the selectable one-way clutch has a ratchet mechanism,
the ratchet mechanism is configured such that the part of the strut, which is projected to the second clutch member side, is operated so as not to be engaged with the part of the second clutch member when a differential rotation speed is equal to or higher than a first differential rotation speed on a positive side,
the ratchet mechanism is configured such that the part of the strut is operated so as to be engaged with the part of the second clutch member when the differential rotation speed is lower than the first differential rotation speed,
a first target differential rotation speed is set as a target value of the differential rotation speed for maintaining the differential rotation speed to be positive in the lock rotation control,
the first target differential rotation speed is set as a value that is lower than the first differential rotation speed,
the first differential rotation speed has a specified differential rotation speed range between an upper limit of the first differential rotation speed and a lower limit of the first differential rotation speed,
the ratchet mechanism is configured such that the part of the strut is not engaged with the part of the second clutch member when the differential rotation speed is equal to or higher than the upper limit of the first differential rotation speed, and that the part of the strut is engaged with the part of the second clutch member when the differential rotation speed is equal to or lower than the lower limit of the first differential rotation speed, and
a second differential rotation speed is set as a value that is higher than the lower limit of the first differential rotation speed and that is lower than the upper limit of the first differential rotation speed.

8. The control system according to claim 1 , wherein
a third differential rotation speed is set as an upper limit on a positive side for maintaining the differential rotation speed to be positive in the lock rotation control, and
the electronic control unit is configured to stop the lock rotation control, when the differential rotation speed becomes equal to or higher than the third differential rotation speed during execution of the lock rotation control.

9. The control system according to claim 1 , wherein
the selectable one-way clutch has a ratchet mechanism

Assignees

• Toyota Motor Co Ltd

Inventors

• Shibata Hiroyuki
• Shioiri Hiroyuki
• Komada Hideaki
• KUROSAKI Yuki

Classifications

• F16H48/10

  with orbital spur gears · CPC title

• B60K6/383 Primary

  One-way clutches or freewheel devices · CPC title

• F16D2500/3166

  Detection of an elapsed period of time · CPC title

• B60K6/445

  Differential gearing distribution type · CPC title

• F16D41/14 Primary

  the effective stroke of the pawl being adjustable · CPC title