JPS63112175U

JPS63112175U -

Info

Publication number: JPS63112175U
Application number: JP416587U
Authority: JP
Priority date: 1987-01-14
Filing date: 1987-01-14
Publication date: 1988-07-19

Description

[Brief explanation of the drawing]

第１図ないし第７図は本考案の実施例に係り、
第１図は電動式パワーステアリング機構の概略構
成図、第２図はモータ駆動装置のブロツク回路図
、第３図はモータ駆動装置の具体的な回路図、第
４図は動作説明に供する波形図、第５図はフルブ
リツジ部分を抜粋した概略の回路図、第６図はフ
ライホイール・ダイオードによる電流継続効果を
示す波形図、第７図は入力トルクに対する出力ト
ルクのリニアリテイを説明する特性図である。１……右操舵時導通保持用の第１のＦＥＴ、２
……右操舵時高速スイツチング用の第２のＦＥＴ
、３……左操舵時導通保持用の第３のＦＥＴ、４
……左操舵時高速スイツチング用の第４のＦＥＴ
、Ｍ……ステアリングモータ、２２……発振回路
、２３……ＤＣ―ＤＣコンバータ、ＦＤ_１〜ＦＤ
_４……ＦＥＴ内部のＰＮ接合を利用したフライホ
イール・ダイオード。 Figures 1 to 7 relate to embodiments of the present invention,
Fig. 1 is a schematic configuration diagram of the electric power steering mechanism, Fig. 2 is a block circuit diagram of the motor drive device, Fig. 3 is a specific circuit diagram of the motor drive device, and Fig. 4 is a waveform diagram for explaining operation. , Fig. 5 is a schematic circuit diagram excerpting the full bridge part, Fig. 6 is a waveform diagram showing the current continuity effect due to the flywheel diode, and Fig. 7 is a characteristic diagram explaining the linearity of output torque with respect to input torque. . 1...First FET for maintaining continuity during right steering, 2
...Second FET for high-speed switching when steering to the right
, 3...Third FET for maintaining continuity during left steering, 4
...Fourth FET for high-speed switching during left steering
, M... Steering motor, 22... Oscillation circuit, 23... DC-DC converter, FD ₁ to FD
₄ ...A flywheel diode that uses the PN junction inside the FET.

Claims

[Claims for Utility Model Registration] A first FET (field effect transistor) for maintaining continuity when steering to the right, a second FET for high-speed switching when steering to the right, and a third FE for maintaining continuity when steering to the left.
T and 4th FET for high-speed switching when steering to the left
and a bridge circuit configured by connecting the steering motor to the steering motor to form a full bridge; and the first FE based on the detection of the right steering torque.
The third F is controlled to conduct and maintain this conductive state, and the third F
A continuity maintenance control unit that controls the ET to conduct and maintain this continuity state, and a DC power supply that generates a DC power supply for this continuity maintenance control unit.
A DC converter, an oscillation circuit that oscillates at a frequency higher than the audio frequency range, and a pulse width modulation signal that generates a pulse width modulation signal with a duty corresponding to the magnitude of the right steering torque based on the oscillation frequency of this oscillation circuit, and this pulse width modulation signal. The second FET is switched at high speed based on the oscillation frequency of the oscillation circuit, and a pulse width modulation signal with a duty corresponding to the magnitude of the left steering torque is generated based on the oscillation frequency of the oscillation circuit. a high-speed switching control section that controls FET No. 4 to perform high-speed switching, and a positive terminal of the high-speed switching control section is connected to a power input terminal connected to a battery, and a drive of the DC-DC converter. A motor drive device for electric power steering, characterized in that an input terminal for the oscillation circuit is connected to an oscillation output terminal of the oscillation circuit.