Brake pad wear and temperature sensor

Patent metadata

Field	Value
Publication number	US-9964168-B1
Application number	US-201615346756-A
Country	US
Kind code	B1
Filing date	Nov 9, 2016
Priority date	Nov 9, 2016
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A brake pad monitoring sensor includes an erodible, electrically non-conductive body, and an electrical circuit disposed within the body. The electrical circuit includes a first wear indicating portion. Electrical continuity of the first wear indicating portion is broken when the body erodes, in response to abrasion against a brake rotor, beyond a first depth relative to a contact surface of the body, to sense a first degree of wear. The electrical circuit includes a first thermocouple that is operable to generate a temperature dependent voltage signal for sensing a temperature of the brake pad. The brake pad monitoring sensor may be used to determine both brake pad wear, and brake pad temperature.

First claim

The invention claimed is:

1. A brake pad monitoring sensor comprising:
an erodible, electrically non-conductive body;
an electrical circuit disposed within the body, and including a first wear indicating portion, wherein electrical continuity of the first wear indicating portion is broken when the body erodes beyond a first depth relative to a contact surface to sense a first degree of wear;
wherein the electrical circuit includes a second wear indicating portion, wherein electrical continuity of the second wear indicating portion is broken when the body erodes beyond a second depth relative to the contact surface to sense a second degree of wear, with the second depth being farther from the contact surface than the first depth;
wherein the first wear indicating portion and the second wear indicating portion are connected in a parallel circuit, in which the first wear indicating portion is disposed in a first path of the parallel circuit and the second wear indicating portion is disposed in a second path of the parallel circuit; and
wherein the electrical circuit includes a first thermocouple operable to generate a temperature dependent voltage signal for sensing a temperature.

2. The brake pad monitoring sensor set forth in claim 1 , wherein the first thermocouple is one of a type J thermocouple or a type K thermocouple.

3. The brake pad monitoring sensor set forth in claim 1 , wherein the first thermocouple includes a first conductor from a first material and a second conductor from a second material, with the first material different from the second material.

4. The brake pad monitoring sensor set forth in claim 1 , wherein the first thermocouple is integral with the first wear indicating portion of the electrical circuit.

5. The brake pad monitoring sensor set forth in claim 4 , wherein a first conductor and a second conductor of the first thermocouple extend generally perpendicular to the contact surface.

6. The brake pad monitoring sensor set forth in claim 1 , wherein the electrical circuit includes a second thermocouple integral with the second wear indicating portion and operable to generate a temperature dependent voltage signal for sensing a temperature.

7. The brake pad monitoring sensor set forth in claim 6 , wherein a first conductor and a second conductor of the second thermocouple extend generally perpendicular to the contact surface.

8. The brake pad monitoring sensor set forth in claim 1 , wherein the electrical circuit includes at least one resistor electrically connected to one of the first wear indicating portion and the second wear indicating portion of the electrical circuit.

9. A vehicle comprising:
a rotor;
a brake pad moveably coupled to the rotor;
an electronic brake control module;
a brake pad monitoring sensor positioned to wear concurrently with and to the same degree as the brake pad, the brake pad monitoring sensor including:
an erodible, electrically non-conductive body having a contact surface for wearing against the rotor;
an electrical circuit disposed within the body and electrically connected to the electronic brake control module, the electrical circuit including a first wear indicating portion providing electrical continuity, wherein the electrical continuity of the first wear indicating portion is broken when the body erodes beyond a first depth relative to the contact surface;
wherein the electrical circuit includes a second wear indicating portion providing electrical continuity, wherein the electrical continuity of the second wear indicating portion is broken when the body erodes beyond a second depth relative to the contact surface, with the second depth being farther from the contact surface than the first depth;
wherein the first wear indicating portion and the second wear indicating portion are connected in a parallel circuit, in which the first wear indicating portion is disposed in a first path of the parallel circuit and the second wear indicating portion is disposed in a second path of the parallel circuit;
wherein the electrical circuit includes a first thermocouple operable to generate a temperature dependent voltage signal; and
wherein the electronic brake control module is operable to determine electrical continuity in the first wear indicating portion to sense a first degree of wear of the brake pad when electrical continuity in the first wear indicating portion is broken, and the temperature dependent voltage signal from the first thermocouple to sense a temperature of the brake pad.

10. The vehicle set forth in claim 9 , wherein the first thermocouple is integral with the first wear indicating portion of the electrical circuit, and wherein a first conductor and a second conductor of the first thermocouple extend generally perpendicular to the contact surface.

11. The vehicle set forth in claim 9 , wherein the electrical circuit includes a second thermocouple integral with the second wear indicating portion and operable to generate a temperature dependent voltage signal for sensing a temperature.

12. The vehicle set forth in claim 11 , wherein a first conductor and a second conductor of the second thermocouple extend generally perpendicular to the contact surface.

13. The vehicle set forth in claim 9 , wherein the brake pad monitoring sensor is positioned within and supported by the brake pad.

14. The vehicle set forth in claim 9 , wherein the electrical circuit includes at least one resistor electrically connected to one of the first wear indicating portion and the second wear indicating portion of the electrical circuit.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Pennala John W
• Nisonger Robert L
• Amatyakul Phanu
• Krueger Eric E
• Weber Steven J

Classifications

• F16D66/024

  Sensors mounted on braking members adapted to contact the brake disc or drum, e.g. wire loops severed on contact · CPC title

• F16D66/027 Primary

  Sensors therefor · CPC title

• F16D2066/001

  Temperature · CPC title

• F16D66/021 Primary

  using electrical detection or indication means · CPC title