Spring having a built-in deformation sensor

• US 9,352,629 B2
• Filed: 12/10/2012
• Issued: 05/31/2016
• Est. Priority Date: 12/13/2011
• Status: Expired due to Fees

• Current Assignee: Renault Sas (Renault)
• Original Assignee: Renault Sas (Renault)
• Inventors: Chabanon, Christian, Jacques, Anthony
• Primary Examiner(s): Kirkland, III, Freddie
• Application Number:
  US14/365,382
• Publication Number:
  US 20150033838A1
• Time in Patent Office: 1,268 Days
• Field of Search: 731/170.3
• US Class Current: 1/1
• CPC Class Codes: B60G 11/14 having helical, spiral or coil springs only B60G11/006 takes precedence
• CPC Class Codes: B60G 11/15 Coil springs resisting deflection by winding up
• CPC Class Codes: B60G 2202/12 Wound spring
• CPC Class Codes: B60G 2202/143 subjected to compression
• CPC Class Codes: B60G 2204/12422 anchoring the end coils on the spring support plate
• CPC Class Codes: B60G 2204/2022 using a suspension element (e.g. link, damper or spring) as part of the electrical circuitry
• CPC Class Codes: B60G 2206/426 Coil springs having a particular shape, e.g. curved axis, pig-tail end coils
• CPC Class Codes: B60G 2206/7101 Fiber-reinforced plastics [FRP]
• CPC Class Codes: B60G 2400/60 Load
• CPC Class Codes: B60G 2401/144 Fiber optic sensor
• CPC Class Codes: F16F 1/3605 characterised by their material F16F1/362, F16F1/364, F16F1/366, F16F1/37 take precedence; composition of macromolecular compounds in general C08L
• CPC Class Codes: F16F 1/3665 Wound springs
• CPC Class Codes: F16F 1/368 Leaf springs
• CPC Class Codes: G01B 11/18 using photoelastic elements
• CPC Class Codes: G01D 5/35316 using a Bragg gratings
• CPC Class Codes: G01D 5/35387 using wavelength division multiplexing
• CPC Class Codes: G01G 19/08 for incorporation in vehicles
• CPC Class Codes: G01L 1/242 the material being an optical fibre
• CPC Class Codes: G01L 1/246 using integrated gratings, e.g. Bragg gratings
• CPC Class Codes: G01M 11/086 Details about the embedment of the optical fiber within the DUT
• CPC Class Codes: G01M 17/04 : Suspension or damping

Abstract

A spring including a composite structure including reinforcement fibers in a matrix. The composite structure further includes at least one Bragg cell and at least one optical fiber connected to the Bragg cell.

Claims

1. A spring comprising:

a composite structure comprising reinforcement fibers within a matrix,

wherein the composite structure comprises at least one optical fiber positioned within the matrix of the spring and at least one Bragg cell, the optical fiber being connected to the Bragg cell.

2. The spring as claimed in claim 1, wherein the spring has a helicoidal shape and comprises a wire formed of the composite structure and wound in a spiral around a first axis to form the helicoidal shape, the wire having a substantially circular cross-section and extending along a second axis of the composite structure, wherein the optical fiber is within the wire and oriented in a direction defined by the reinforcement fibers.

3. The spring as claimed in claim 2, wherein the optical fiber is adjacent to an external contour of the wire.

4. The spring as claimed in claim 2, wherein the at least one Bragg cell includes a first Bragg cell and a second Bragg cell, the second Bragg cell being arranged with respect to the first Bragg cell at a distance substantially equivalent to a distance covered by the optical fiber when the optional fiber forms a half-revolution about the second axis of the wire.

5. The spring as claimed in claim 2, wherein the reinforcement fibers are inclined at an angle with respect to the second axis, the angle being in a range of 30°

to 50°

.

6. The spring as claimed in claim 2, wherein the reinforcement fibers are unidirectional.

7. The spring as claimed in claim 2, wherein the optical fiber includes an output end that extends out of a bottom end of the wire of the spring.

8. The spring as claimed in claim 2, wherein the optical fiber includes an output end that extends out of the wire of the spring before a bottom end of the wire.

9. The spring as claimed in claim 1, wherein the spring has a longitudinal axis and comprises platelets extending substantially along the longitudinal axis and within at least one of them the optical fiber runs longitudinally.

10. The spring as claimed in claim 9, wherein the at least one Bragg cell includes a first Bragg cell and a second Bragg cell arranged longitudinally, each respectively disposed on either side of a point of maximum bending moment, the first and second Bragg cells defining distances with a point of maximum bending moment substantially equal to one another and defining between them a controlled distance.

11. The spring as claimed in claim 9, wherein the at least one Bragg cell includes a first Bragg cell and a second Bragg cell arranged longitudinally, each respectively disposed on either side of a point defining a middle of the platelet along the longitudinal axis, the first and second Bragg cells defining distances with a point defining a middle of the platelet substantially equal to one another and defining between them a controlled distance D.

12. A device for measuring a load on at least one wheel of a vehicle, the device comprising:

a shock absorber device for the wheel comprising a spring as claimed in claim 1, configured to be mounted onto the wheel;

a source module configured to emit light signals toward the Bragg cell of the spring;

a receiver module configured to receive signals transmitted by the Bragg cell and to convert the signals into output data; and

a processor module configured to process output data and to calculate a load on the wheel including the spring.

13. A vehicle including for its traction a wheel, comprising a spring as claimed in claim 1.

14. A method for measuring a load on at least one wheel of a vehicle, the method comprising:

installing at least one optical fiber with Bragg cells, forming a sensor for measuring deformations and comprising the Bragg cells, in a spring, the spring including a composite structure comprising reinforcement fibers within a matrix, the optical fiber being positioned within the matrix of the spring;

emitting, by a source module, tight signals toward each Bragg cell;

each Bragg cell returning a light signal to a receiver module;

converting, at the receiver module, the light signals into output data and transmits the output data to a processor module; and

processing, at the processor module, the output data and calculating the toad on the wheel equipped with the spring.