Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Tadayuki Hara

Mitsuharu Morishita

Shinichi Kohge

Hajime Kozuka

Hisato Umemaru

Yasuaki Hata

Tetsushi Watanabe

Isao Yamamoto

Yasuki Ikari

Shunichi Wada

Yasuo Naito

Kazuhisa Nishino

Koji Terauchi

Yoshimi Kotake

A motor-driven power steering apparatus and method for a vehicle are able to avoid frequent on-off operations of an electromagnetic clutch 14 as much as possible, which connects or disconnects a motor 13 with or from a steering system, thus improving the durability of the clutch 14 and suppressing the generation of undesirable noise and shocks upon connection and disconnection of the clutch 14. A clutch controller 191 controls a clutch current Ic supplied to the clutch 14 based on the vehicle speed V in such a manner that it sets the clutch current Ic to a first predetermined clutch current level I(V) so as to place the clutch into a substantially engaged state when the vehicle speed V is less than a first predetermined vehicle speed Vo, and to a second predetermined clutch current level Icr which is less than the first predetermined clutch current level I(V) so as to place the clutch into a partially engaged state when the vehicle speed V is equal to or greater than the first predetermined vehicle speed Vo. Preferably, the clutch current Ic is set to a third predetermined clutch current level Ico which is less than the second predetermined clutch current level Icr so as to substantially disengage said electromagnetic clutch when a steering torque T is equal to or greater than a predetermined value To when the vehicle speed is equal to or greater than the first predetermined value Vo.

Motor-driven power steering apparatus and method

An electromagnetic solenoid comprises a coil wound around a coil case and a plunger inserted into the coil so as to be slidable in the axial direction, wherein a tape impregnated with a thermosettable resin is wound on the trunk portion of the coil case and the coil is wound on the wound tape.

Electromagnetic solenoid

Power steering apparatus with unitary torque sensor and worm driving

A steering torque detecting device includes a steering shaft consisting of an input shaft and an output shaft, a torsion bar provided between the input shaft and the output shaft, a torque detecting unit for converting a quantity of torsion produced in the torsion bar into an electric output, an electricity collecting unit including slip rings and brushes which takes the electric output and supplies an electric power from an outer power source, bearings for supporting the input and output shaft on the same axial line, and a housing supporting the bearings, a printed wiring board in a circular plate form which is provided at its one surface with a resistance layer and an output electrode radially spaced apart from the resistance layer, the resistance layer and the output electrode constituting a potentiometer, and a slider having a portion extending in the radial direction of the circular printed wiring board so as to have contacting areas with a small width to the resistance layer and the output electrode.

Steering torque detecting device

A steering torque detecting device comprises a steering shaft consisting of an input shaft and an output shaft, a torsion bar provided between the input shaft and the output shaft, a torque detecting unit for converting a quantity of torsion produced in the torsion bar into an electric output, an electricity collecting unit comprising slip rings and brushes which takes the electric output and supplies an electric power from an outer power source, bearings for supporting the input and output shaft on the same axial line, and a housing supporting the bearings, a printed wiring board in a circular plate form which is provided at its one surface with a resistance layer and an output electrode radially spaced apart from the resistance layer, the resistance layer and the output electrode constituting a potentiometer, and a slider having a portion extending in the radial direction of the circular printed wiring board so as to have contacting areas with a small width to the resistance layer and the output electrode.

An electromagnetic solenoid for a fluid control valve includes a cylindrical casing accommodating a solenoid coil and having an end wall formed at its one end and which is open at its other end, the open end of the casing being closed by an end cap. A fixed iron core is disposed in and fixedly mounted on the casing. An output rod is disposed in the casing with its one end extending outwardly through the casing end wall for connection with a valve member of the fluid control valve. The output rod slidably extends through the fixed iron core and is supported on its opposite ends by a slide bearing disposed in the end wall of the casing and by a slide ball bearing disposed in the end cap member. A movable iron core is received in the solenoid coil for axial sliding movement and is firmly mounted on the output rod in a face-to-face relation with the fixed iron core at a location such that the distance between the center of the movable iron core and the slide ball bearing is less than the distance between the center of the movable iron core and the slide bearing. The output rod and the slide bearing in the casing end wall are formed of a non-magnetic material. In one embodiment, the end wall of the casing has a fluid passage formed therethrough for providing fluid communication between the interior of the casing and the outside. In another embodiment, the slide bearing in the end wall of the casing has a fluid passage formed therethrough for providing fluid communication between the interior of the casing and the housing bore.

A motor-driven power steering system for a vehicle preventing transmission of operating noises of the motor to the interior of the passenger compartment of the vehicle and for suppressing the generation of radio wave noises: a speed sensor for detecting the travelling speed of the vehicle; a torque sensor mounted on a steering shaft for detecting turning force imparted to the steering wheel by an operator, a first pinion operatively connected with the steering shaft and adapted to be driven by the steering wheel through the intermediary of the steering shaft, a rack operatively connected through tie rods with a pair of steerable road wheels and having a first rack tooth portion and a second rack tooth portion formed thereon, a second pinion being in meshing engagement with the second rack tooth portion on the rack, a motor operatively connected with the second pinion for power assisting the steering motion of the rack induced by the operator a first electromagnetic clutch interposed between the motor and the second pinion for transmitting power therebetween substantially in proportion to the intensity of current supplied thereto, a second clutch interposed between the motor and the second pinion for selectively establishing or disconnecting the operative connection between the motor and the second pinion, and a control unit adapted to receive output signals from the speed sensor and the torque sensor for controlling the operations of the motor, the first clutch and the second clutch.

Motor-driven power steering system for a vehicle

An electromagnetic solenoid for use with a fluid control valve is disclosed in which a fixed iron core and a casing for housing a solenoid coil can be fabricated separately from each other without difficulty, and in which the configuration and the clearance between the fixed iron core and a movable iron core or the length of the extension of the fixed iron core from an end wall of the casing can be readily changed in accordance with the desired magnetic attraction characteristics thereof as required. The cylindrical casing has an end wall formed at its one end and is open at its other end, the open end being closed by an end cap member to form a yoke for a magnetic circuit. The fixed iron core is adapted to be separably connected with the end wall of the casing. An output rod is disposed in the casing with its one end extending outwardly through the end wall of the casing, the output rod slidably extending through the fixed iron core and being supported at its opposite ends by the end wall of the casing and the end cap member through a pair of slide bearings for axial sliding movement. A movable iron core is received in the hollow of the solenoid coil and fixedly mounted on the output rod in a face-to-face relation with the fixed iron core. The end wall of the casing has an insertion bore formed therein, and the fixed iron core has its one end firmly fitted into the insertion bore.

Electromagnetic solenoid with a replaceable fixed iron core

A power steering apparatus for an automobile or other vehicle has a motor which rotates a steering shaft through an electromagnetic clutch and a worm gear reduction gear. When the clutch is engaged, the rotation of the motor causes the rotation of the steering shaft. When the clutch is disengaged, the steering shaft is not connected to either the reduction gear or the motor and can therefore be rotated manually with the same force as for a manual steering apparatus. The reduction gear and the electromagnetic clutch are coaxially disposed around the steering shaft.

Power steering apparatus

A power steering apparatus for an automobile or other vehicle has a steering shaft constituted by an input section and an output section connected by a torsion bar. A mechanism for detecting when a driver is imparting torque to the steering wheel of the vehicle is constituted by a potentiometer having a resistive element and a wiper arm, one of which is mounted on the output section and the other of which is mounted on the torsion bar so that the wiper arm will rotate with respect to the resistive element and the resistance of the potentiometer will change when the torsion bar is rotated with respect to the output section. The potentiometer is electrically connected to a preamplifier mounted on the steering shaft, and the preamplifier is electrically connected to slip rings through which its output can be supplied to a stationary control unit. The electrical output of the potentiometer is independent of the speed of rotation of the steering wheel.

An electromagnetic solenoid device for oil pressure control comprises a movable iron core for pushing an oil pressure valve body attached at one end of the solenoid device and a space filled with working oil in which the movable iron core is slidably moved, wherein at least one oil pressure releasing part is formed in the movable iron core, extending from the front end to the rear end of the movable iron core in the direction of its sliding movement.

Electromagnetic solenoid device for oil pressure control

An electromagnetic solenoid device comprises a plunger loosely fitted in a coil so as to be slidable in the axial direction by the actuation of the coil, wherein the plunger is placed in a through hole of the coil at the side of an end plate which is provided at an end of a yoke and the plunger has an inclined portion for increasing magnetic resistance between an end of the plunger and the end plate.

Growing community of inventors

Himeji, Japan

Tadayuki Hara