Koyo Seiko Company, Ltd.

Jtekt Corporation

Denso Corporation

Other

Nakanishi Metal Works Co., Ltd.

Yoshitomo Tokumoto

Naoki Nakane

Toshiharu Ishihara

Mahito Shiba

Naoki Maeda

Kenichi Kotaka

Takeshi Izumi

Yutaro Ishimoto

Osamu Sano

Tetsuya Murakami

Norio Nakatani

Taisuke Tsujimoto

Hiroshi Kichise

Kaname Aoki

Kazuya Sakai

Kaname Joushita

Shingo Takayama

Mikio Nozaki

Shunsuke Nakaura

Ken Fukuda

Noriyuki Yahata

Takashi Kaoku

Takanori Hamada

Masashi Hashiya

Tadashi Kitahata

Sinji Hakamata

Tomoharu Horiuchi

Munehisa Nakamura

Takeshi Izumu

Provided is a sensor system capable of more accurately detecting abnormality. A sensor IC includes a first detector, a second detector, and a communication circuit. The first detector and the second detector output a first digital value and a second digital value according to the strength of a magnetic flux applied thereto, respectively. The communication circuit transmits the first and second digital values received from the first and second detectors to a control device. At this time, the communication circuitplaces the first and second digital values in a plurality of frames to transmit the plurality of frames. The communication circuit forms the plurality of frames such that bit information data of the first and second digital values placed in the frames is arranged in different orders between the first and second digital values.

Sensor system

A torque detector includes a permanent magnet, a pair of magnetic yokes, and a magnetic sensor. The magnetic yokes include a first magnetic yoke and a second magnetic yoke. The first magnetic yoke has a first ring and a plurality of first teeth extending from the first ring in an axial direction. The second magnetic yoke has a second ring and a plurality of second teeth extending from the second ring in the axial direction. The first teeth extend in the axial direction beyond the second ring of the second magnetic yoke. The second teeth extend in the axial direction beyond the first ring of the first magnetic yoke.

Torque detector and electric power steering system including the torque detector

A torque detection device has a magnetic flux collecting ring, arranged outside an outer periphery of a magnetic circuit forming member which is provided in a rotating body applied with a torque, for collecting a magnetic flux generated by the magnetic circuit forming member; a detector for detecting the torque applied to the rotating body based on a density of the magnetic flux collected by the magnetic flux collecting ring; and a holding ring for holding the magnetic flux collecting ring and the detector and including an attachment part to be attached to a stationary object on an outer periphery on one side in a radial direction. An attachment-preventing convex part for preventing attachment to the stationary object by contacting the stationary object is formed on one end face in an axis line direction of the holding ring.

Torque detection device and electric power steering apparatus using the same

There is provided a torque detecting device including: magnetic flux concentrating rings which locate on a magnetic circuit forming member provided in a rotating body to which a torque is exerted, the rings concentrating a magnetic flux generated by the member; a detecting part which detects the torque to the rotating body based on a density of the magnetic flux concentrated by the rings; and a holding ring which holds the magnetic flux concentrating rings and the detecting part and includes an attachment portion attaching to a stationary substance, on a circumference of the holding ring. Both end faces of the holding ring in an axial direction of the holding ring are substantially parallel. The attachment portion includes a fitting groove into which a sealing ring, which seals a gap between the attachment portion and the stationary substance, fits.

Torque detecting device and electric power steering apparatus using the same

A torque detecting apparatus is provided which is capable of easily positioning a magnetic sensor in relation to a corresponding pair of magnetism collecting projections and thus improving the detection accuracy of the magnetic sensor without increasing the number of assembling and processing steps. A pair of magnetism collecting projectionsandof each magnetism collecting ringare arranged to extend not in their respective radial directions but substantially in parallel to each other while two magnetic sensorsandare mounted to a circuit boardand inserted along the direction of projection of the magnetism collecting projectionsandinto the air gaps respectively between the two magnetism collecting projectionandof one magnetism collecting ringand the two magnetism collecting projectionandof the other magnetism collecting ring

Torque detecting apparatus

A yoke assembly is constructed by retaining integrally a yoke ring having positioning holes aligned with pole claws arranged equally on the inner circumference and a yoke ring having positioning holes aligned with the space between pole claws arranged equally on the inner circumference by a retaining cylinder made of a resin. The retaining cylinder has a pin hole remaining after pulling out a common positioning pin inserted into the positioning holes during molding.

Torque detecting device and manufacturing method of yoke assembly

Magnetic pole nails. . . aligned on magnetic yokesthat integrally rotate with the second shaftare formed in a rectangular shape, and the circumferential width and alignment pitch of the magnetic pole nails. . . are appropriately determined with respect to the magnetization pitch of the N-poles. . . and the S-poles. . . circumferentially aligned on the cylindrical magnetthat integrally rotates with the first shaftso that a variation in magnetic flux generated on the magnetic yokein accordance with the relative displacement between the cylindrical magnetand the magnetic yokeuniformly takes place in a larger amplitude. Thus, a torque detecting apparatus that achieves higher detection accuracy with a simple structure can be provided.

A detecting unit for detecting a torque applied to a rotor according to rotation of the rotor having an input shaft and an output shaft connected with each other by a torsion bar and a detection circuit board connected with the detecting unit are molded with synthetic resin material to form a mold member. The installation of the mold member into a housing, which has a cylinder portion to surround the rotor and a retainer having an opening formed at the peripheral wall of the cylinder portion, is achieved by inserting the mold member into the retainer from the radial direction through the opening of the retainer.

Torque detecting apparatus and manufacturing method thereof

An inventive torque detection device includes: a magnetic circuit forming member having a tubular magnet provided at a first rotating body, and a magnetic ring that is located circumferentially of the tubular magnet and rotated together with a second rotating body connected to the first rotating body; a magnetic flux collecting ring part for collecting a generated magnetic flux; a detection part for detecting, based on a density of the collected magnetic flux, a torque applied to the first or second rotating body; and a molded body that is molded at an outer circumferential portion of the first rotating body, and is joined to longitudinal both sides of the tubular magnet so as to fix the tubular magnet to the first rotating body. A molding pressure, generated when the tubular magnet is molded, is applied in the longitudinal direction of the tubular magnet.

Torque detection device

The number n of N-poles and S-poles circumferentially aligned on the cylindrical magnet that integrally rotates with the first shaft is determined so as to be a greatest integer that satisfies the following formula that includes a maximum value T(Nm) of the torque to be detected and a torsion spring constant k (Nm/deg) of the torsion bar connecting the first shaft and the second shaft: 2&#xb7;n&#xb7;T/k&#x3c;360. The cylindrical magnet includes teeth-shaped portions in which portions corresponding to the N-poles and the S-poles are of a protruding shape, so that adhesion of magnetic dust concentrates at the protruding portions. Thus, a torque detecting apparatus is provided that reduces the effect of the adhesion of the magnetic dust, so as to attain higher detection sensitivity and thereby improve the detection accuracy, without incurring an increase in cost.

A torque detecting apparatus according to the present invention includes a first shaft and a second shaft connected coaxially to each other through a connecting shaft, a permanent magnet fixed to the first shaft, a plurality of soft magnetic members having a collar provided therein, fitted by pressing with the second shaft and disposed in a magnetic field of the permanent magnet to form a magnetic circuit, and a detector for detecting magnetic flux generated from the soft magnetic members, wherein the soft magnetic members are integrally molded with a mold body made of synthetic resin, and when a torque is applied to the first shaft or the second shaft, the torque is detected based on an output of the detector. The collar is made of a non-magnetic material.

Torque detecting apparatus and electric power steering apparatus

A torque detecting apparatus detects torque applied upon a torsion bar of an electric power steering apparatus, as two sensors, which have ratiometric characteristics and have the same characteristics, simultaneously detect the amount of torsion of the torsion bar. With a gain of one of the two sensors set to the positive polarity and a gain of the other sensor set to the negative polarity, a control circuit calculates the torque applied upon the torsion bar by multiplying a difference between detection outputs from the two sensors by a predetermined coefficient. A torque detecting apparatus which is capable of detecting the torsional angle of a rotation shaft, namely, torque applied upon the rotation shaft easily and accurately using two sensors is thus realized.

In a torque detecting apparatus, in each of two flux concentrating rings, a portion along a circumferential direction is raised outward in a radial direction so that a flux concentrating section is provided that has a plate shape extending on one side in an axial direction. These flux concentrating rings are fixedly arranged such that the flux concentrating sections should oppose to each other in the circumferential direction with a predetermined gap in between. Leakage flux between opposing surfaces of the flux concentrating sections is detected by magnetic sensors aligned in an axial direction between these opposing surfaces. This improves the utilization of materials for the flux concentrating rings including the flux concentrating sections, and hence reduces the product cost.

An electric power steering system includes: a first rotation detection section including a first sensor section and outputting a signal corresponding to a rotation of an input shaft; a second rotation detection section including second and third sensor sections and outputting signals corresponding to a rotation of an output shaft; and a control unit detecting the respective rotational angles of the input and output shafts and a torque applied to a torsion bar based on the output signals from these rotation detection sections, and providing a driving control of an electric motor. The control unit makes determination on the occurrence of failure at the first to third sensor sections, and provides the driving control of the electric motor as shifting the driving control, based on results of the determination, between a torque control mode using the detected value of the torque and a steering angle control mode using the detected value of the rotational angle of either one of the input and output shafts.

Electric power steering system

A rotational angle detecting apparatus, in which first targets and second targets, the number thereof is coprime with each other, are provided at the rotors rotating coaxially with each other. Rotational angle of the rotor is detected based on the detection signals from each of two sensors disposed opposite to the targets respectively, which output detection signals having phases different from each other as the rotor rotates. Based on a magnitude relation between one detection signal and the other detection signal from each of the two sensors, the range of the electrical angle of the other detection signals is determined. Relation between a detection signal and an electrical angle is stored in advance. Based on the determined electrical angle, and referring to the relation, the electrical angle of the other detection signal is obtained; thus, the rotational angle of the rotor is detected.

Growing community of inventors

Nabari, Japan

Yoshitomo Tokumoto