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US 8,942,898 B2Granted
Range switchover apparatus
AssigneeDenso Corporation
InventorJun Yamada
Life of this patent
Estimating the term…
Abstract
In a range switchover control apparatus, a microcomputer checks, under a state that driving force of a motor is released, whether a range switchover mechanism is at rest and whether the range switchover mechanism is at rest in a bottom position, that is, whether an engagement member is fitted deep into a bottom of a range holding recess. If the range switchover mechanism is at rest in the bottom position, an encoder count value at a reference position (bottom position of a P-range) is calculated based on a present range and an encoder count value. By using the present range and the calculated encoder count value, an encoder count value of the bottom position of the present range can be determined. Based on this encoder count value, the encoder count value at the reference position can be calculated.
Claims8
A range switchover apparatus comprising:
- a motor;
- a range switchover mechanism for switching over a shift range among plural ranges by the motor as a drive source;
- an encoder for outputting a pulse signal in synchronism with rotation of the motor;
- a detent mechanism for holding the range switchover mechanism at each range position by allowing an engagement member to be fitted in a range holding recess, when the range switchover mechanism is switched over to each range position;
- and
- a control unit for controlling a switchover position of the range switchover mechanism by rotationally driving the motor based on an encoder count value indicative of a count value of the pulse signal of the encoder, wherein:
- the control unit is configured to perform a resting check, a range check and a reference position calculation,
- the resting check checks whether the range switchover mechanism is at rest with the engagement member being fitted in a bottom position of the range holding recess, by checking whether the range switchover mechanism is at rest with the drive force of the motor being released,
- the range check checks which one of the ranges the present shift range is,
- the reference position calculation calculates the encoder count value at a predetermined reference position based on the present shift range determined by the range check and the encoder count value, when the range switchover mechanism is determined to be at rest in the bottom position by the resting check;
- the range check checks the present shift range by performing hitting control, in which the motor is rotationally driven to a limit position of a movable range of the range switchover mechanism, and thereafter performing hitting return control, in which the motor is rotationally driven in reverse to return the range switchover mechanism from the limit position to the bottom position;
- and
- the resting check determines that the range switchover mechanism is at rest, when a change amount of the encoder count value is less than a predetermined value.
10 more elements
A range switchover apparatus comprising:
- a motor;
- a range switchover mechanism for switching over a shift range among plural ranges by the motor as a drive source;
- an encoder for outputting a pulse signal in synchronism with rotation of the motor;
- a detent mechanism for holding the range switchover mechanism at each range position by allowing an engagement member to be fitted in a range holding recess, when the range switchover mechanism is switched over to each range position;
- and
- a control unit for controlling a switchover position of the range switchover mechanism by rotationally driving the motor based on an encoder count value indicative of a count value of the pulse signal of the encoder, wherein:
- the control unit includes a resting check, a range check and a reference position calculation,
- the resting check checks whether the range switchover mechanism is at rest with the engagement member being fitted in a bottom position of the range holding recess, by checking whether the range switchover mechanism is at rest with the drive force of the motor being released,
- the range check checks which one of the ranges the present shift range is;
- the reference position calculation calculates the encoder count value at a predetermined reference position based on the present shift range determined by the range check and the encoder count value, when the range switchover mechanism is determined to be at rest in the bottom position by the resting check;
- the range check checks the present shift range by performing hitting control, in which the motor is rotationally driven to a limit position of a movable range of the range switchover mechanism, and thereafter performing hitting return control, in which the motor is rotationally driven in reverse to return the range switchover mechanism from the limit position to the bottom position;
- and
- the resting check determines that the range switchover mechanism is at rest when the drive force of the motor is continuously released for more than a predetermined period.
10 more elements
Dependencies are inferred from the claim text.