Honda Giken Kogyo Kabushiki Kaisha

Yasuharu Ohyama

Yasuo Shimizu

Katsuji Watanabe

Atsuhiko Yoneda

Shigeru Yamawaki

Yasuhiro Terada

Tetsuro Hamada

Katsuhiro Sakai

Masaki Izawa

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.

Electric power steering apparatus

A parking aid system having a driver initially stop the subject vehicle alongside a target parking position so that a mark provided inside a door coincides with the central line of the target parking position when assisting the driver with left reverse parking. The subject vehicle is a predetermined distance away from an entrance of the target parking position, when the driver turns the operation switch ON. A display unit then displays the target parking position, the subject vehicle position, and an expected parking position. The expected parking position is set at a position that the subject vehicle reaches when reversing with the steering wheel turned fully to the left. Therefore, when the driver moves the subject vehicle forward to a position where the expected parking position coincides with the target parking position and reverses the subject vehicle from that position through 90&deg; while turning the steering wheel fully to the left, the subject vehicle can reliably be guided to the target parking position.

Parking aid system

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.

An active suspension system and an active suspension control method for a vehicle having a first wheel set and a second wheel set, comprising a power actuator interposed between the vehicle body and each of the wheels; a sensor for detecting turning maneuver of the vehicle; and a control unit for controlling operation of the actuators according to data obtained from the sensor so as to reduce a vertical load acting on the inner wheel of the second wheel set which bears a less vertical load than the first wheel set during the turning maneuver. Thereby, the shifting of the vertical load between the wheels of the first wheel set is reduced with the result that the overall cornering force of the vehicle is maximized because of the saturating property of the maximum cornering force of the tire in relation with the vertical load acting thereon.

Growing community of inventors

Wako, Japan

Yasuharu Ohyama