Electro-mechanical impact detecting device for vehicles

• US 6,512,310 B1
• Filed: 10/27/2000
• Issued: 01/28/2003
• Est. Priority Date: 11/24/1999
• Status: Expired due to Fees

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Ohnishi, Jun
• Primary Examiner(s): Sircus, Brian
• Assistant Examiner(s): Deberadinis, Robert L.
• Application Number:
  US09/697,303
• Time in Patent Office: 823 Days
• Field of Search: 307/121, 307/9.1, 307/10.1, 307/10.7
• US Class Current: 307/121
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: G01P 15/0891 with indication of predetermined acceleration values G01P15/135 takes precedence
• CPC Class Codes: G01P 15/135 by making use of contacts which are actuated by a movable inertial mass
• CPC Class Codes: H01H 35/14 Switches operated by change of acceleration, e.g. by shock or vibration, inertia switch wherein the liquid constitutes a contact of the switch H01H29/002

Abstract

An electro-mechanical impact detecting device for a vehicle is provided which implements a multi-stage control for vehicle occupant protection systems and improves the operational delay characteristics of the vehicle occupant protection systems at an irregular collision based on the setting of multiple impact levels which are detected. When a main rotor rotates by a certain amount against the exertion force of a moving contact, the moving contact and fixed contact close the circuit, thereby detecting the first impact level. When the main rotor further rotates against the exertion force of the torsional coil spring, the remaining two pairs of fixed contacts and close the circuits sequentially, thereby detecting the second and third impact levels, respectively.

Claims

1. An electro-mechanical impact detecting device for a vehicle, the device comprising:

a first rotating member, which pivots to rotate about a center of rotation in response to an impact acted on the vehicle, first rotating member having a center of mass that is eccentric from the rotation center;

a second rotating member, which pivots to rotate about a center of rotation in response to the impact and has a center of mass that is eccentric from the rotation center of the second rotating member, wherein the first and second rotating members are adjacent to each other;

a first switch, which closes a circuit at a first rotation value of the first rotating member corresponding to a first impact level of the impact; and

a second switch, which closes a circuit at a second rotation value of the second rotating member corresponding to a second impact level of the impact, wherein the first and second rotating members are different in shape from each other such that a distance between the first rotating member and the rotation center of the first rotating member is different from that between the second rotating member and the rotation center of the second rotating member, and wherein at least the first and second impact levels are detected on a basis of closing of the switches.

2. The electro-mechanical impact detecting device according to claim 1 further comprising:

a shaft, which rotatably supports the first and second rotating members; and

an exerting means, which provides the shaft with a predetermined force that forces each rotating member to return to an initial position.

3. The electro-mechanical impact detecting device according to claim 1, wherein the first switch includes a first fixed contact and a first flat-spring moving contact, which is moved toward the first fixed contact by a rotational movement of the first rotating member, and wherein the second switch includes a second fixed contact and a second flat-spring moving contact, which is moved toward the second fixed contact by a rotational movement of the second rotating member.

4. The electro-mechanical impact detecting device in claim 3, wherein each rotating member includes a cam for pushing each flat-spring moving contact, wherein each flat-spring moving contact contacts a surface of each cam after each switch is closed as each cam rotates, and wherein the surface of each cam is shaped not to increase a bending value of each flat-spring moving contact.

5. An electro-mechanical impact detecting device for a vehicle according to claim 1, wherein the impact detecting device includes a detection signal generation means which generates detection signals in response to the closing of the switches at stepped values which match with at least the first and second impact levels.

6. An electro-mechanical impact detecting device for a vehicle according to claim 5, wherein:

the second impact level is set greater than the first impact level;

the detection signal generation means includes a first and second electrical load element, the detection signal generation means arranged as an electrical circuit including a closing circuit having one of the switches which is closed at the first impact level and the first electrical load element, and another closing circuit including one of the switches which disclosed at the second impact level and the first and second electrical load elements.

7. An electro-mechanical impact detecting device for a vehicle, the device comprising:

a first rotating member, which pivots to rotate about a center of rotation in response to an impact acted on the vehicle and the first rotating member having a center of mass that is eccentric from the rotation center;

a second rotating member, which pivots to rotate about a center of rotation in response to the impact and has a center of mass that is eccentric from the rotation center of the second rotating member, wherein the first and second rotating members are adjacent to each other;

a first switch, which includes a first fixed contact and a first moving contact, which is moved toward the first fixed contact by a rotational movement of the first rotating member, for closing a circuit at a rotation value of the first rotating member corresponding to a first impact level of the impact; and

a second switch, which includes a second fixed contact and a second moving contact, which is moved toward the second fixed contact by a rotational movement of the second rotating member, for closing a circuit at a rotation value of the second rotating member corresponding to a second impact level of the impact, wherein the second impact level is greater than the first impact level, wherein at least the first rotating member includes a cam for pushing the first moving contact, wherein the first moving contact contacts a surface of the cam after the first switch is closed as the cam rotates, wherein the surface of the cam is shaped not to increase a bending value of the first moving contact, and wherein at least the first and second impact levels are detected on a basis of closing of the first and second switches.

8. The electro-mechanical impact detecting device according to claim 7, further including:

a shaft, which rotatable supports the first and second rotating members; and

an exerting means, which provides the shaft with a predetermined exertion force that forces each rotating member to return to an initial position.

9. The electro-mechanical impact detecting device according to claim 7, wherein each moving contact is made from a flat-spring.