Drive control device and fuel pump drive system

Patent metadata

Field	Value
Publication number	US-10103658-B2
Application number	US-201415032061-A
Country	US
Kind code	B2
Filing date	Nov 10, 2014
Priority date	Nov 12, 2013
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A microcomputer of a drive control device for controlling the driving of a brushless motor has a positioning part and a torque acceleration control unit. The positioning unit controls the power to be supplied to the windings, to thereby position the rotor at a drive start position which is a position of the rotor relative to the stator at which the drive control of the brushless motor can start, before starting the drive control of the brushless motor. The torque acceleration control unit controls the power to be supplied to the windings so that a torque acceleration falls within a predetermined range that the collision stress generated when the outer wall of the end of the shaft collides with the inner wall of the hole of an impeller (rotating member) is equal to or smaller than a predetermined value, when the rotor is positioned.

First claim

The invention claimed is:

1. A drive control device that controls the driving of a brushless motor having a stator on which multi-phase windings are wound, a rotor that is disposed to be rotatable relative to the stator, and a shaft that is disposed in the center of the rotor, has an end fitted into a hole of a rotating member and rotates together with the rotor, the drive control device comprising:
a control unit that operates an energization output including at least one of a current, a voltage and a power, and controls a power to be supplied to the windings to make the rotation of the rotor controllable, wherein
the control unit includes:
a positioning unit that controls the power to be supplied to the windings to position the rotor at a drive start position which is a position of the rotor relative to the stator which can start the drive control of the brushless motor, before starting the drive control of the brushless motor; and
a torque acceleration control unit that controls the power to be supplied to the windings to allow a torque acceleration, which is a time variation in a torque output from the shaft, to fall within a predetermined range that the collision stress generated when the outer wall of the shaft collides with the inner wall of the rotating member is equal to or smaller than a predetermined value, when the rotor is positioned by the positioning unit.

2. The drive control device according to claim 1 , wherein
the positioning unit includes:
a position detection unit that energizes the multi-phase windings, rotates the stopped rotor, and detects a position of the rotor relative to the stator;
a position determination unit that determines the drive start position on the basis of the position of the rotor which is detected by the position detection unit; and
a positioning processing unit that switches the energization of the multi-phase windings and rotates the rotor to position the rotor at the drive start position determined by the position detection unit.

3. The drive control device according to claim 2 , wherein
the torque acceleration control unit sets a second output value which is a value of the energization output until the outer wall of the shaft collides with the inner wall of the rotating member to be smaller in a positioning process by the positioning processing unit after the position determination unit determines the drive start position, and switches the energization, than a first output value which is a value of the energization output when the position detection unit detects the position of the rotor.

4. The drive control device according to claim 3 , wherein
the second output value is set to be constant.

5. The drive control device according to claim 2 , wherein
the brushless motor is a three-phase brushless motor in which three-phase windings are wound on the stator,
the position detection unit energizes the windings of two phases, and detects the position of the rotor on the basis of an induced voltage developed in a deenergized phase, and
the positioning processing unit energizes the windings of three phases, and positions the rotor.

6. The drive control device according to claim 1 , wherein
the torque acceleration control unit controls the power to be supplied to the wirings to make the torque acceleration after the outer wall of the shaft collides with the inner wall of the rotating member larger than the torque acceleration before the shaft collides with the rotating member.

7. The drive control device according to claim 1 , wherein
the torque acceleration control unit controls the power to be supplied to the windings to keep the torque acceleration at a predetermined target value under a PI control.

8. A fuel pump drive system comprising:
a fuel pump including a brushless motor that can output a torque with the rotation of a shaft, a housing that houses the brushless motor, a pump cover that has a suction part and covers one end of the housing, a cover end that has a discharge part and covers the other end of the housing, and a rotating member that has a hole defined in the center of the rotating member into which an end of the shaft is fitted, and rotates together with the shaft to pressurize a fuel flowing from the suction part and discharge the fuel from the discharge part; and
a drive control device that controls the driving of the brushless motor according to claim 1 .

9. The fuel pump drive system according to claim 8 , wherein
the end of the shaft is formed into a D-shape in a cross-section perpendicular to an axis,
the hole is formed into a D-shape corresponding to the cross-sectional shape of the end of the shaft, and
a predetermined clearance is defined between the end of the shaft and the hole in a state where the end of the shaft is fitted into the hole.

Assignees

• Denso Corp

Inventors

• Hidaka Yuuji
• Nagata Kiyoshi
• Ootake Masaya
• Toyoda Hirokazu
• Nomura Manabu

Classifications

• H02P2203/03

  Determination of the rotor position, e.g. initial rotor position, during standstill or low speed operation · CPC title

• H02P6/188

  using the voltage difference between the windings (H02P6/182 takes precedence) · CPC title

• H02P6/20 Primary

  Arrangements for starting (H02P6/08 takes precedence) · CPC title

• H02P6/182

  using back-emf in windings · CPC title

• H02P6/22 Primary

  in a selected direction of rotation · CPC title