Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Yasuhiro Terada

Yasuo Shimizu

Katsuji Watanabe

Atsuhiko Yoneda

Shigeru Yamawaki

Yasuharu Ohyama

Takashi Yanagi

Yutaka Horiuchi

Nobuo Sugitani

Kouhei Maruyama

Hajime Kajiwara

Takahiro Aoki

Takehiko Hakui

Kotaro Yamaguchi

Ryoji Toyofuku

A steering controller for an electric power steering deviceincludes a base signal computing partfor computing a base signal Din accordance with at least the steering torque; a damper compensation signal computing partfor computing a damper compensation signal in accordance with an angular velocity of an electric motoror a speed of steering wheel turn; and an inertia compensation signal computing partfor compensating inertia and viscosity in the steering unit. The electric motor is driven by a target signal IMobtained by compensating the base signal with a damper compensation signal and an inertia compensation signal, to provide a steering auxiliary force. The target signal of the auxiliary torque is compensated so that a difference between a reference self-aligning torque of front wheel in a front wheel steering vehicle and a self-aligning torque of front wheel in an all-wheel steering vehicle is provided to a driver as a responsive feeling from the steering torque.

Steering system

Worm gear mechanism includes a driving worm, a torque delivering worm wheel meshing with the worm, and an auxiliary worm wheel superimposed on the torque delivering worm wheel. The auxiliary worm wheel has a pitch diameter greater than that of the torque delivering worm wheel. The auxiliary worm wheel is biased against the driving worm wheel via a biasing member in the form of a leaf spring.

Worm gear mechanism and electric power steering apparatus equipped with the worm gear mechanism

A telescopic actuator is adapted to be used on a right side or a left side of a body. The telescopic actuator includes a housing having a cylindrical shape and formed with an opening portion, an output rod supported inside the housing so as to be protrudable and retractable with respect to the housing, and a stroke sensor comprising a detectable portion provided on the output rod so as to be movable inside the opening portion of the housing and a detecting portion provided on the housing so as to face the detectable portion. A direction in which the detectable portion is eccentrically disposed with respect to a vertical plane including an axial line of the output rod is different depending on whether the telescopic actuator is used on the right side or on the left side of the body.

Telescopic actuator

Electric power steering apparatus includes an electric motor for producing steering assist torque corresponding to steering torque applied to a steering system, and a worm gear mechanism for transmitting the steering assist torque to the steering system. The worm of the worm gear mechanism has a pressure angle greater than a pressure angle of the worm wheel, so as to reduce an actual meshing pitch circle diameter of the worm in the worm gear mechanism.

Electric power steering apparatus

An electric power steering apparatus with an electric motor generating an assistant steering force for transmission to the steering system, a worm shaft rotated by the electric motor, a worm gear on the worm shaft that rotates therewith, a worm wheel rotated by the worm gear, a pinion shaft that rotates with the worm gear, supporting units that support both ends of the worm shaft so as to allow rotation thereof, and a distortion prevention unit that prevents distortion of the worm shaft. The supporting units may support the ends of the worm shaft without play.

Electric motor assist type power steering apparatus

An electric power steering apparatus comprising a rack shaft having two racks, a first rack-and-pinion mechanism for transferring a steering torque to the rack shaft, and a second rack-and-pinion mechanism for transferring an assist torque to the rack shaft. The second rack-and-pinion mechanism includes a pinion and a rack both being helical gears so that a large torque can be transmitted to the rack shaft. Teeth of the pinion and rack are arc profiled. The arc profiled teeth mesh with each other through a large contact area of concave and convex surfaces thereof and hence with a reduced contact pressure compared to involute profiled teeth. The arc profiled teeth thus have increased surface fatigue strength, bending strength and bending fatigue strength and can transmit an assist torque sufficiently to the rack shaft. Moreover, they have durability sufficient to withstand a torque load of a motor inertia.

A magnetostrictive torque sensor includes a magnetostrictive film of width W provided along a circumference of a rotational shaft. The film causes magnetostriction in correspondence to a torque applied to the rotational shaft. The torque sensor also includes excitation and detection cores each having substantially U-shaped configuration. These cores are disposed in opposed relation to the film. The excitation core extends through an excitation coil while the detection core extends through a detection coil. The excitation core is disposed on the detection core at right angles. The film has a magnetic path passing therethrough. The magnetic path, the excitation coil, and the detection coil cooperate with each other to provide a magnetic circuit. The excitation coil and the detection coil provides a bridge circuit in cooperation with each other. When a torque is applied to the rotational shaft, the film causes magnetostriction in correspondence to the torque. The magnetostriction is electrically detected by the bridge circuit.

Magnetostrictive torque sensor and electric power steering apparatus including the same

An electric power steering apparatus having a motor for producing assist torque according to the steering torque, and a rack and pinion mechanism for transferring torque assistance to the rack shaft. The pinion and rack of the rack and pinion mechanism are both helical gears, and transfer high torque to the rack shaft. The helical gears have a curved arc tooth profile. The teeth of a curved arc tooth profile gear set mesh with contact between convex and concave surfaces. The contact area is therefore increased and contact pressure is decreased compared with involute teeth. Surface fatigue strength, bending strength, and bending fatigue strength are thus greater compared with involute teeth. The combined steering torque and assist torque is efficiently transferred to the rack shaft, and durability is sufficient to withstand torque loads from motor inertia.

Growing community of inventors

Wako, Japan

Yasuhiro Terada