Seat Belt Retractor, Control Method Thereof, and Seat Belt Device

• US 20070295852A1
• Filed: 10/19/2005
• Published: 12/27/2007
• Est. Priority Date: 10/19/2004
• Status: Active Grant

• Current Assignee: Autoliv Development AB (Autoliv Incorporated)
• Original Assignee: Autoliv Development AB (Autoliv Incorporated)
• Inventors: Midorikawa, Yukinori
• Granted Patent: US 9,539,981 B2
• Time in Patent Office: Days
• US Class Current: 242/390.9
• CPC Class Codes: B60R 2022/4473 using an electric retraction device
• CPC Class Codes: B60R 22/44 with means for reducing belt tension during use under normal conditions not included in the retractor B60R22/19; B60R22/3405 takes precedence

Abstract

A seat belt retractor 100 includes stop state detecting means 118 which detects that a driving signal is not inputted to power generation means 110 and drawing-direction rotation detecting means 119 which detects that the power generation means 110 is rotating in a drawing-direction of a webbing 302. Here, a control means 200 controls the power generation means 110 to rotate in the drawing direction of the webbing 302, when the stop state detecting means 118 detects that the driving signal is not inputted to the power generation means 110 and the drawing-direction rotation detecting means 119 detects that the power generation means 110 is rotating in the drawing direction of the webbing 302.

Claims

1. A seat belt retractor comprising:

a spindle winding a webbing;

a power generation means which generates power for rotating the spindle in a desired direction;

a power transmission means that enables transmission of the power of the power generation means to the spindle when the power generation means generates the power for rotating the spindle in a winding direction of the webbing, and also disables transmission of the power of the power generation means to the spindle when the power generation means generates a power in a direction opposite to the power for rotating the spindle in the winding direction;

a control means which drives and controls the power generation means;

a stop state detecting means which detects that a driving signal is not inputted to the power generation means; and

a drawing-direction rotation detecting means which detects that the power generation means is rotating in the drawing direction of the webbing,

wherein the control means drives and controls the power generation means to rotate in the drawing direction of the webbing, when the stop state detecting means detects that the driving signal is not inputted to the power generation means and the drawing direction detecting means detects that the power generation means is rotating in the drawing direction of the webbing.

2. The seat belt retractor according to claim 1, wherein the power generation means is an electric motor, and

the stop state detecting means and the drawing-direction rotation detecting means detect by measuring an electromotive force of the electric motor.

3. The seat belt retractor according to claim 1, further comprising:

a drawing preventing means which prevents the webbing from being drawn by stopping the rotation of the spindle in the drawing direction of the webbing, when a rotational acceleration of the spindle in the drawing direction of the webbing is a predetermined value or more, or when a deceleration of a vehicle is a predetermined value or more; and

a winding spring applying a torque in the winding direction of the webbing to the spindle.

4. A seat belt device having the seat belt retractor according to claim 1.

7. The seat belt retractor according to claim 2, further comprising:

a drawing preventing means which prevents the webbing from being drawn by stopping the rotation of the spindle in the drawing direction of the webbing, when a rotational acceleration of the spindle in the drawing direction of the webbing is a predetermined value or more, or when a deceleration of a vehicle is a predetermined value or more; and

a winding spring applying a torque in the winding direction of the webbing to the spindle.

5. A method of controlling a retractor comprising a spindle winding a webbing, a power generation means which generates power for rotating the spindle in a desired direction, and a power transmission means that enables transmission of the power of the power generation means to the spindle when the power generation means generates the power for rotating the spindle in a winding direction of the webbing, and also disables transmission of the power of the power generation means to the spindle when the power generation means generates a power in a direction opposite to the power for rotating the spindle in the winding direction, the method comprising:

judging whether a connection between the spindle and the power generation means by the power transmission means is released when the spindle rotates in the drawing direction of the webbing; and

controlling to drive the power generation means to rotate in the drawing direction of the webbing when the connection by the power transmission means is not released.

6. The method according to claim 5, wherein when it is detected that a driving signal is not inputted to the power generation means and it is detected that the power generation means is rotating in the drawing direction of the webbing, it is judged that the connection by the power transmission means is not released.