Braking-force-maintaining device for vehicle and electric braking device for vehicle

Patent metadata

Field	Value
Publication number	US-2018073584-A1
Application number	US-201615554050-A
Country	US
Kind code	A1
Filing date	Mar 31, 2016
Priority date	Mar 31, 2015
Publication date	Mar 15, 2018
Grant date	—

Abstract

In an electric braking device for a vehicle, the following are carried out in order: a first lock process in which either torque for shifting the ratchet gear in a release direction is generated in an electric motor or the driving of the electric motor is stopped, while a pawl member is being pressed against a ratchet gear; a second lock process in which the rotational angle of the ratchet gear is brought to an angle different from a semi-engaging rotational angle by driving the electric motor; and a third lock process in which the ratchet gear is rotated in the release direction by driving the electric motor in reverse.

First claim

1 . A braking-force-maintaining device for a vehicle, configured to maintain a braking force applied to a wheel by maintaining a force pressing a friction member against a rotor which rotates integrally with the wheel, the braking-force-maintaining device, comprising:
a displacement member which includes at least one tooth and in which the force pressing the friction member against the rotor increases when the displacement member is displaced in a braking direction which is one of specified directions, and the pressing force decreases when the displacement member is displaced in a release direction which is another one of the specified directions; a pawl member configured to move forward and backward in a direction toward or away from the displacement member and regulate displacement of the displacement member in the release direction when the pawl member is meshed with the tooth; and a control device configured to control a first driving source which is a driving source of the displacement member and a second driving source which is a driving source of the pawl member, wherein in a case where a position of the displacement member in the specified direction at a time when a tip of the pawl member is in contact with a tip of the tooth is defined as a semi-engaging position, the control device performs: a first lock process configured to generate a torque to displace the displacement member in the release direction in the first driving source, or configured to stop driving the first driving source generating a torque to displace the displacement member in the braking direction, under a circumstance that the pawl member is pressed against the displacement member by driving the second drive source; a second lock process performed after end of the first lock process and configured to displace the displacement member in the braking direction or the release direction by driving the first driving source and set a position of the displacement member in the specified direction to a position different from the semi-engaging position; and a third lock process performed after end of the second lock process and configured to displace the displacement member in the release direction under a circumstance that the pawl member is pressed against the displacement member by driving the second driving source.

2 . The braking-force-maintaining device for a vehicle according to claim 1 , comprising a position detector configured to detect a position of the displacement member in the specified direction,
wherein the displacement member has a configuration in which a plurality of the teeth is disposed along the specified direction, when a position of the displacement member in the specified direction at a time when the execution of the first lock process is finished is defined as a reference position, in the second lock process, the control device displaces the displacement member from the reference position in the specified direction by driving the first driving source and stops driving the first driving source when a displacement amount of the displacement member from the reference position in the specified direction reaches a specified displacement amount, and in a case where the specified displacement amount is denoted by “ΔMkaTh2”, an interval between the teeth adjacent to each other in the specified direction is denoted by “PH”, “N” is a positive integer of 0 (zero) or larger, and “M” is a value larger than 0 (zero) and less than “1”, the specified displacement amount can be expressed by a relational formula described below:
Δ MkaTh 2=( N+M )× PH.

3 . The braking-force-maintaining device for a vehicle according to claim 1 ,
wherein the pawl member allows the displacement of the displacement member in the braking direction when the pawl member is meshed with the tooth of the displacement member, the displacement member has a plurality of the teeth disposed along the specified direction, in the second lock process, under a circumstance that the pawl member is pressed against the displacement member by driving the second driving source, the control device sets a position of the displacement member in the specified direction to a position different from the semi-engaging position, by displacing the displacement member in the braking direction by driving the first driving source, and in a case where a torque to displace the displacement member in the braking direction by driving the first driving source is defined as a displacement torque, a minimum displacement torque capable of displacing the displacement member in the braking direction is defined as a specified torque reference value, and a maximum displacement torque capable of regulating that a displacement amount of the displacement member in the braking direction exceeds an interval of the teeth adjacent to each other in the specified direction is defined as a regulatable torque reference value, in the second lock process, the control device set the displacement torque to a torque larger than the specified torque reference value and smaller than the regulatable torque reference value by driving the first driving source.

4 . The braking-force-maintaining device for a vehicle according to claim 1 , comprising
a position detector configured to detect a position of the displacement member in the specified direction, wherein when a position of the displacement member in the specified direction at a time when the pawl member is pressed against the displacement member by driving the second driving source prior to execution of the first lock process is defined as a specific position, the control device does not perform the second lock process and the third lock process in the case where a displacement amount of the displacement member from the specific position in the release direction, associated with the execution of the first lock process is larger than a meshing determination displacement amount.

5 . The braking-force-maintaining device according to claim 1 ,
wherein the control device performs the second lock process when determining that the pawl member regulates displacement of the displacement member in the release direction by performing the first lock process.

6 . A braking-force-maintaining device for a vehicle, configured to maintain a braking force applied to a wheel by maintaining a force pressing a friction member against a rotor which rotates integrally with the wheel, the braking-force-maintaining device, comprising:
a displacement member which includes at least one tooth and in which the force pressing the friction member against the rotor increases when the displacement member is displaced in a braking direction which is one of specified directions, and the pressing force decreases when the displacement member is displaced in a release direction which is another one of the specified directions; a pawl member configured to move forward and backward in a direction toward or away from the displacement member and regulate displacement of the displacement member in the release direction when the pawl member is meshed with the tooth; and a control device configured to control a first driving source which is a driving source of the displacement member and a second driving source which is a driving source of the pawl member, wherein in a case where a position of the displacement member in the specified direction at a time when a tip of the pawl member is in contact with a tip of the tooth is defined as a semi-engaging position, when a braking force applied to the wheel is maintained by engaging the pawl member with the displacement member, the control device determines whether there is a possibility that the displacement member is positioned at the semi-engaging position and performs an engagement correction processing in which

Assignees

• Advics Co Ltd

Inventors

• Tsukamoto Shun
• Kokubo Koichi

Classifications

• F16D65/14 Primary

  Actuating mechanisms for brakes; Means for initiating operation at a predetermined position (brake control systems, parts thereof B60T) · CPC title

• B60T13/74

  with electrical assistance or drive · CPC title

• B60T8/17

  Using electrical or electronic regulation means to control braking {(detecting or indicating faulty operation B60T8/885)} · CPC title

• F16D2127/06

  Locking mechanisms, e.g. acting on actuators, on release mechanisms or on force transmission mechanisms · CPC title

• B60T1/005 Primary

  by locking of wheel or transmission rotation · CPC title