Ntn Corporation

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Hitachi Astemo Ueda Co., Ltd.

Hitachi Astemo Ltd.

Nippon Steel Sumitomo Metal Corporation

Tatsuya Yamasaki

Masaaki Eguchi

Yui Masuda

Makoto Muramatsu

Tomomi Goto

Hiromitsu Toyota

Haruo Kotera

Hiromasa Satoh

Yusuke Koga

Toshihiro Obika

Makoto Yasui

Yuuki Saoyama

Koichi Okada

Tomoaki Makino

Yoshitaka Nagano

Nobuyuki Suzuki

Kenji Imanishi

Isao Hori

Yasutaka Noguchi

Yuki Saoyama

Akiyoshi Nishikawa

Yasushi Aoki

Yoshinori Itakura

Akira Saito

Katsuhisa Yamaguchi

Takehito Sakurai

Masahiro Tasaka

A vehicle brake system () includes a first control device () and a second control device () that respectively include a master controller (), a first sub-controller (), and a second sub-controller () that are connected to one another. Each of the master controller (), the first sub-controller (), and the second sub-controller () includes a braking force calculation unit that calculates braking force of electric brakes (to), and a determination unit that compares braking force calculation results of the controllers to determine whether itself is normal. The determination unit includes an output block section that blocks, when the determination unit determines that any one of the controllers is not normal, an output of the controller that is determined to be not normal.

Vehicle brake system

A highly reliable vehicle brake system that includes an electric brake and achieves redundancy at low cost is provided. A vehicle brake system () is provided to a wheel (Wa) of a vehicle (VB), and includes an electric brake () provided with a motor (), a driver () that drives the motor (), and a first control device () provided with a master controller () and a first sub-controller () connected to each other. The electric brake () is controllable by both the master controller () and the first sub-controller ().

A highly reliable vehicle brake system including an electric brake is provided. A vehicle brake system () includes electric brakes (to) provided with motors (to), drivers (to) that drive the motors (to), and a control device that controls the drivers (to). The electric brake () includes two motors (and), and the control device includes separate drivers (and) respectively corresponding to the two motors (and). The control device includes a first master controller () and a first sub-controller (). The first master controller () controls the driver () corresponding to the motor (), and the first sub-controller () controls the driver () corresponding to the motor

A load sensor to be used in an electromechanical brake system includes a flange member capable of deflecting when receiving, at a load receiving portion, a load from the axially front side; a support member capable of supporting the flange member from the axially rear side, at a support portion displaced from the load receiving portion in a radial direction orthogonal to the axial direction; and a displacement detecting mechanism configured to detect the amount of relative movement between the flange and support members. A variable detection sensitivity mechanism enables the relative movement amount with respect to the change of the load applied to the flange member to be larger in a low load range in which the load is equal to or lower than a predetermined load value than in a high load range in which the load is higher than the predetermined load value.

Load sensor and electromechanical brake system

Provided is an electric brake device capable of adjusting a clearance without making a driver feel discomfort, in a vehicle equipped with the electric brake device. A control device () of this electric brake device (DB) includes: a brake operation amount detector () to detect an operation amount to a brake operation member () of the vehicle; and an operation record flag storage unit () to store an operation record flag indicating a record of a latest operation performed by the driver to the brake operation member (), on the basis of the operation amount detected by the brake operation amount detector (). The control device () further includes a target clearance determination unit () to determine a target clearance with reference to the operation record flag stored in the operation record flag storage unit ().

Electric brake device

In an electric linear motion actuator, while an axially forward load is not being applied to an object by an outer ring member, a preload is applied to a frictionally coupling surface by an elastic member, and, when the axially forward load is applied to the object by the outer ring member, an axial load applied to the frictionally coupling surface decreases by an amount equal to the axially rearward reaction force which the outer ring member receives from the object. The electric linear motion actuator includes a load sensor for supporting, through planetary rollers and a carrier, the axially rearward reaction force. The load sensor is arranged such that any change in magnitude of an axially forward load applied through a snap ring will not affect the value of the axially rearward reaction force detected by the load sensor.

Electric linear motion actuator and electromechanical brake system

An electric linear motion actuator is provided which includes an outer ring member, a rotary shaft, planetary rollers, and a carrier including a disk, and in which the outer ring member is formed with a helical rib, each of the planetary rollers being formed with circumferential grooves in which the helical rib is engaged. When the rotary shaft rotates, the planetary rollers rotate about their axes while revolving around the rotary shaft so that the outer ring member axially linearly moves. The actuator includes thrust roller and retainer assemblies each mounted between one of the planetary roller and the disk of the carrier, and each guided by a raceway, i.e., an end surface of the corresponding planetary roller. The actuator includes a common raceway disk common to all of the thrust roller and retainer assemblies, and mounted between the thrust roller and retainer assemblies and the disk of the carrier.

The electric brake device includes an electric motor, a friction member operator, a friction member, a brake rotor, and a control device. A braking force estimator provided in the control device includes: a direct estimator configured to convert output of a braking force sensor which detects a load or displacement corresponding amount, to a braking force; and an indirect estimator configured to estimate the braking force on the basis of information other than output of the braking force sensor. A range in which the braking force is estimated by the direct estimator is a specified low-braking-force range, and in a range beyond this range, estimation of the braking force is performed by the indirect estimator.

Electrically powered brake device

The electric brake device includes an electric motor, a brake rotor, a friction pad, a conversion mechanism, a braking force command section, a braking force estimation section, a controller, and a power supply device. The controller includes: a power determination section to determine whether an amount of remaining power that can be supplied from a power supply device to the electric motor has become equal to or less than a determined value; and a residual pressure cancellation section to cancel a residual pressure of a braking force by driving the electric motor in a direction opposite to a brake pressing direction such that an estimated value of the braking force obtained by the braking force estimation section becomes equal to or less than a set value, when the power determination section determines that the amount of remaining power has become equal to or less than the determined value.

An electric linear motion actuator includes an outer ring member provided around a central shaft, and planetary rollers disposed between the central shaft and the outer ring member. One of the central shaft and the outer ring member serves as an input member which is rotatable and immovable in the axial direction and rotated by an electric motor, while the other serves as an output member which is rotationally stationary and movable in the axial direction. The input member has a peripheral surface formed with a plurality of annular ribs which are equal in pitch. Each planetary roller has a radially outer surface formed with annular grooves which are equal in pitch to the annular ribs and in which the annular ribs are engaged. The output member has a peripheral surface formed with a helical rib which is equal in pitch to the annular grooves of the planetary rollers.

Electric linear motion actuator and electric disk brake system

It is an object of the present invention to improve seal performance in an electric linear motion actuator configured to linearly drive a linear motion member due to the rotation of a rotary shaft. The linear motion member is constituted by a cylindrical member slidably fitted in a housing, and a pressing member coupled to the distal end portion of the cylindrical member so as to close the opening of the distal end of the cylindrical member. The portion of the pressing member coupled to the cylindrical member is located inside of a boot sealing the space between the distal end portion of the housing and the distal end portion of the linear motion member.

Electric linear motion actuator and electric brake system

An electric brake device includes an electric motor; a braking force application mechanism configured to apply a braking force on a vehicle wheel; a lock mechanism configured to assume one of a locked condition; a temperature sensor configured to measure an ambient temperature of a vehicle; and a freezing preventive power supply unit configured to initiate supply of an electric power to the electric motor or a drive source of the lock mechanism. The freezing preventive power supply unit interrupts the supply of the electric power to the electric motor or the drive source of the lock mechanism when the temperature detected by the temperature sensor exceeds a second preset temperature Tthat is higher than a first preset temperature T

The electric linear motion actuator includes an electric motor, a drive shaft configured to be rotated by the electric motor, a rotation-to-linear motion converting mechanism configured to convert the rotational motion of the drive shaft to the axial linear motion of an axially movably supported outer ring member, and an electric locking mechanism incorporated in a reduction gear mechanism in which the rotation of a rotor shaft of the electric motor is reduced in speed and transmitted to the drive shaft. When the electric locking mechanism is energized, the power transmission path shifts to the locked state in which power cannot be transmitted, and when the electric locking mechanism is de-energized thereafter, the power transmission path is kept in the locked state. The electric locking mechanism is built in a motor case of the electric motor so that the electric motor and the electric locking mechanism are unitized.

An electric linear motion actuator includes planetary rollers mounted between the radially inner surface of an outer ring member and the radially outer surface of a rotary shaft, and a carrier rotatable about the rotary shaft and including radially movable roller shafts rotatably supporting the respective planetary rollers. Elastic rings each having circumferentially separate ends are each wrapped around the roller shafts to radially inwardly bias the roller shafts, thereby bringing the respective planetary rollers into elastic contact with the radially outer surface of the rotary shaft. Each elastic ring is prevented from rotating relative to the roller shafts, thereby preventing one of the roller shafts from being axially aligned with the gap between the circumferential separate ends, causing the elastic ring to be radially compressed and thus making it impossible for the elastic rings to radially bias the roller shafts.

A linear motion actuator includes an outer ring member mounted in a housing, a rotary shaft rotated by a motor, planetary rollers mounted between the outer ring member and the shaft and supported by a carrier rotatable about the shaft. A helical rib is formed on the inner surface of the outer ring member which is engaged in helical grooves formed in outer surfaces of the planetary rollers. When the shaft rotates, the planetary rollers rotate and revolve, thereby axially moving the outer ring member. Uneven axial loads applied to the planetary rollers from the outer ring member are supported by thrust bearings disposed between the planetary rollers and an inner disk of the carrier. Aligning seats are provided between each opposed pair of the planetary rollers and the thrust bearings such that the contact surfaces of the aligning seats shift relative to each other under the uneven axial loads.

Growing community of inventors

Iwata, Japan

Tatsuya Yamasaki