Mitsuba Corporation

Jidosha Kiki Co., Ltd.

Fujitsu Corporation

Mitsuba Electric Manufacturing Co., Ltd.

Jidoshi Kiki Co., Ltd.

Yoshiaki Taniguchi

Tsugio Onodera

Tadao Kodaira

Masaki Watanabe

Ryuji Iizawa

Takeshi Ohe

Hideaki Fujii

Masayuki Okubo

Susumu Aoki

Yoichi Shindo

Minoru Arai

Wataru Mochizuki

Hiroshi Nishikiori

Yoshihiro Takemoto

Masayuki Ohkubo

Hideyuki Ogawa

Atsushi Hirakata

Fumitoshi Mori

A circuit-container unithas a structure in which a board, electric componentsconstituting a drive control circuit, a framemade of synthetic resin, an insulating platemade of synthetic resin, a shield platemade of aluminum, and a covermade of synthetic resin are stacked over a unit bodymade of aluminum. The unit bodyis constituted by a mount partand a plate-like base part. Component-container portionsandare projected in the lower surface side of the base part. The component-container portionsandare provided to be projected into a gap between the base partand a motor body. The insides of the component-container portionsandserve as container spaces. FETswhich are short in height are provided on the board. Tall capacitorsand relaysare contained in the component-container portionsand. Useless space over the components is thus saved and the space efficiency is improved.

Motor

Motor-driven power steering apparatus

In an electric motor comprising a cylindrical yoke having a side wall at one end portion thereof, a driver unit for controlling and driving the electric motor is contained at an end portion in the side of the side wall in the yoke. A power supply opening portion through which inside and outside of the yoke communicate with each other and a signal line opening portion are formed in the side wall, and an electric connection to the driver unit is made through these portions. The driver unit is provided inside the yoke with FETs thereof kept in direct contact with the side wall. Also, a driver unit which integrates drive control circuitry with a brush holder may be provided and fixed on the outer surface of the side wall. In this case, an opening portion through which inside and outside of the yoke communicate with each other is formed in the side wall, and a brush is inserted through these portions. A driver unit is attached to a yoke with FETs thereof kept in direct contact with the side wall. As a result, in an electric motor having a power supply section provided deep in the yoke closed at its one end, the control drive section and the apparatus body can be integrally provided with each other without hindering the assembling operation.

Motor and electric power steering device

A power steering unit according to the invention scarcely transmits sounds and vibrations coming from the electric motor to the steering wheel of a motor vehicle. It comprises a rack-shaft,to be coupled to the guiding wheels of a vehicle, a housing A for slidably containing the rack-shaft,and holding therein a coupling section,for causing the teeth of the rack-shaft,to engage those of a pinion arranged on the steering column,linked to the steering handle of the vehicle and an electric motor,coaxially arranged around the rack-shaft,which the rotary force is transmitted to the rack-shaft,by way of a ball screw mechanism,as the steering assisting power. It further comprises another housing B, for rotatably supporting the nut section of the ball-and-screw mechanism,the housing B being provided with a fitting section to be secured to the vehicle main body. The housing A is secured to the vehicle main body by a bracket,while the housing B is secured to the vehicle main body by a fitting section

Electric power steering unit

An electric power steering unit comprises a rack-shaft,to be coupled to the guiding wheels of a vehicle, an electric motor,coaxially arranged around the rack-shaft,, a ball screw mechanism,for connecting a nut section,with a screw section,of the rack-shaft,by disposing ball,therebetween and for transmitting the rotary power of the motor,to the rack-shaft,as assisting power for steering, and a housing B comprising an angular bearing,for rotatably supporting the ball screw mechanism,. The angular bearing,comprising outer rings,pressed and fixed in an axial direction in the housing B by an outer ring fixing ring,, and balls,which is provided between the rings,and the nut,and which is in contact with the nut,at a position where a stress is not caused at the ball,by a pressure force applied to the rings

An electric power steering unit comprises a rack-shaft 2 to be coupled to the guiding wheels of a vehicle, a housing A for slidably containing the rack-shaft 2 and holding therein a coupling section 6 for causing the teeth of the rack-shaft 2 to engage those of a pinion arranged on the steering column 5 linked to the steering handle of the vehicle and an electric motor 1 coaxially arranged around the rack-shaft 2, which the rotary force is transmitted to the rack-shaft 2 by way of a ball screw mechanism 3 as the steering assisting power. A yoke 7 of the motor 1 is formed integrally with the housing A, which simplifies the shape of the yoke 7 and reduces production cost.

An electric power steering unit comprises a rack-shaft 2 to be coupled to the guiding wheels of a vehicle, a housing A for slidably containing the rack-shaft 2 and holding therein a coupling section 6 for causing the teeth of the rack-shaft 2 to engage those of a pinion arranged on the steering column 5 linked to the steering handle of the vehicle and an electric motor 1 coaxially arranged around the rack-shaft 2, which the rotary force is transmitted to the rack-shaft 2 by way of a ball screw mechanism 3 as the steering assisting power. A nut section 19 of the ball-screw mechanism 3 is rotatably supported by a housing B separately formed from the housing A, in a state of supporting the armature shaft 11 of the electric motor 1. The rack-shaft 2 is axially movable and supported by two points of support, one at the coupling section and the other at the nut section supported by the housing B. Thus, the rack-shaft is not supported by three points such as the conventional power steering unit but supported by two points, the precision requirements for the components are eased and hence the manufacturing cost thereof is reduced.

An electric power steering unit includes a rack-shaft(2) to be coupled to the guiding wheels of a vehicle, a housing A for slidably containing the rack-shaft(2)and holding therein a coupling section(6)for causing the teeth of the rack-shaft(2)to engage those of a pinion arranged on the steering column(5)linked to the steering handle of the vehicle and an electric motor(1) coaxially arranged around the rack-shaft(2), which the rotary force is transmitted to the rack-shaft(2)by way of a ball screw mechanism 3 as the steering assisting power. A nut section(19)of the ball-screw mechanism(3)is rotatably supported by a housing(B) separately formed from the housing(A), in a state of supporting the armature shaft(11)of the electric motor(1). The rack-shaft(2) is axially movable and supported by two points of support, one at the coupling section and the other at the nut section supported by the housing(B). Thus, the rack-shaft is not supported by three points such as the conventional power steering unit but supported by two points, the precision requirements for the components are eased and hence the manufacturing cost thereof is reduced.

An electric power steering unit has an armature shaft that is free from axial forces and hence may have less rigorous requirements for its strength so that it may be manufactured more efficiently at reduced cost. It comprises a rack-shaft 2 to be coupled to the guiding wheels of a vehicle, a housing A for slidably containing the rack-shaft 2 and holding therein a coupling section 6 for causing the teeth of the rack-shaft 2 to engage those of a pinion arranged on the steering column 5 linked to the steering handle of the vehicle and an electric motor 1 coaxially arranged around the rack-shaft 2, which the rotary force is transmitted to the rack-shaft 2 by way of a ball screw mechanism 3 as the steering assisting power. A nut section 19 is linked to the armature shaft 11 of the electric motor 1 and rotatably supported by the housing B. The reaction force from the rack-shaft 2 generated by the inertia of the armature shaft 11 is transmitted to the housing B by way of the nut section 19 so that the armature shaft 11 is free from any axial force.

The starter motor power cables for the starter motor, having a relatively large cross sectional area and therefore involving a very little voltage drop, are used as a part of the motor drive power cables for the electric power steering system, and the length of the motor drive power cables can be thereby reduced with the net result that the overall voltage drop can be reduced, and a sufficient power output can be produced from the electric power steering system. Also, the reduction in the length of the motor drive power cables reduces the possibility of producing electromagnetic interferences.

Wiring structure for an electric power steering system

In a clutch control method of a motor-driven power steering apparatus, a clutch is disconnected when a change width of a steering angle detected by a steering angle sensor is a predetermined angle or less and a steering torque detected by a torque sensor is a predetermined torque or more in both the steering directions. A clutch controller of a motor-driven power steering apparatus includes a first transistor arranged between one terminal of the clutch coil and a power source, a second transistor arranged between the other terminal of the clutch coil and an earth, and a current sensor connected in series with the first and second transistor.

Clutch control method and clutch controller for motor-driven power

In a control method of an electric power steering apparatus for a vehicle, a target value generator for setting a target value of a steering force or a motor output and a primary delay system with a variable damper value according to a vehicle speed are arranged in a control unit, and an electric power steering unit is controlled using a value obtained by filtering a difference between the target value set by the target value generator and an actual value through the primary delay system.

Control method for electric power steering apparatus for vehicle

In a control method and apparatus of an electric power steering apparatus of this invention, a reverse torque R against a steering torque and a torque produced by the motor are detected, and a target value T.sub.DT which is set based on the reverse torque and is used when the torque produced by the motor is controlled has a range given by T.sub.DT .times.R&gt;R.sup.2.

Apparatus and method of controlling electric power steering apparatus

An electric power steering apparatus includes a torsion bar, input and output shafts, an electric motor, and a detecting mechanism. The input and output shafts are coupled to each other by the torsion bar so as to be pivotally displaced in relation to each other. The electric motor is coupled to the output shaft so as to apply an auxiliary steering force. The detecting mechanism detects a relative, pivotal displacement of the input and output shafts. Main portions of the input and output shafts are coaxially arranged. One of the shafts is a cylindrical member having an outer end in which the torsion bar is housed. An inner end of one shaft is pivotally inserted in an opening of a cylindrical inner end of the other shaft. The detecting mechanism is arranged on the outer surface of an outer shaft of the input and output shafts at their overlap portion. A displacement transmitting portion for transmitting a displacement of one shaft to the detecting mechanism is formed in the inner end of one shaft so as to extend through the other shaft. The detecting mechanism can obtain a relative, pivotal displacement of the input and output shafts from a displacement of one shaft transmitted from the displacement transmitting portion.

Electric power steering apparatus

An electric power steering apparatus causes a bridge circuit and a driver circuit to control normal and reverse rotation operations of a motor. The bridge circuit is constituted by transistors. The driver circuit is connected to a power source and also is connected to the bridge circuit so as to drive the bridge circuit. A diode is inserted between the power source and the bridge circuit, and the polarities of the diode are set such that a voltage at the bridge circuit is lower than that at the driver circuit.

Growing community of inventors

Saitama, Japan

Yoshiaki Taniguchi