PIEZOELECTRIC SENSOR FOR BICYCLE COMPONENT

• US 20160072042A1
• Filed: 07/31/2015
• Published: 03/10/2016
• Est. Priority Date: 09/08/2014
• Status: Active Grant

• Current Assignee: Shimano Inc
• Original Assignee: Shimano Inc
• Inventors: FUKUDA, Masahiko, WATANABE, Yoshiyuki, MASUDA, Takaya
• Granted Patent: US 9,773,966 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B62J 45/00 Electrical equipment arrangements specially adapted for use as accessories on cycles, not otherwise provided for
• CPC Class Codes: B62J 45/41 characterised by the type of sensor
• CPC Class Codes: B62M 3/00 Construction of cranks operated by hand or foot
• CPC Class Codes: B62M 3/08 Pedals
• CPC Class Codes: H02N 2/18 producing electrical output from mechanical input, e.g. generators for measurement devices G01
• CPC Class Codes: H10N 30/302 Sensors
• CPC Class Codes: H10N 30/50 having a stacked or multilayer structure
• CPC Class Codes: H10N 30/852 Composite materials, e.g. having 1-3 or 2-2 type connectivity
• CPC Class Codes: H10N 30/87 Electrodes or interconnections, e.g. leads or terminals

Abstract

A piezoelectric material contains ferroelectric particles and an adhesive resin. The ratio of the ferroelectric particles relative to the total mass of the ferroelectric particles and the adhesive resin is 40 mass % or greater and 98 mass % or less.

Claims

1. A piezoelectric material comprising ferroelectric particles and an adhesive resin, wherein a ratio of the ferroelectric particles relative to a total mass of the ferroelectric particles and the adhesive resin is 40 mass % or greater and 98 mass % or less.

2. The piezoelectric material according to claim 1, wherein the ratio of the ferroelectric particles relative to the total mass of the ferroelectric particles and the adhesive resin is 40 mass % or greater and 90 mass % or less.

3. The piezoelectric material according to claim 1, wherein the ratio of the ferroelectric particles relative to the total mass of the ferroelectric particles and the adhesive resin is 80 mass % or less.

4. The piezoelectric material according to claim 1, wherein an average particle diameter of the ferroelectric particles is 2 μ

m or greater and 10 μ

m or less.

5. The piezoelectric material according to claim 4, wherein the ferroelectric particles are formed by sintering and then pulverizing a resulting sinter.

6. The piezoelectric material according to claim 1, wherein the piezoelectric material has a thickness of 20 μ

m or greater and 200 μ

m or less.

7. A piezoelectric sensor comprising:

the piezoelectric material according to claim 1; and

two electrodes coupled to the piezoelectric material.

8. The piezoelectric sensor according to claim 7, wherein the two electrodes include an outer electrode coupled to an outer surface of the piezoelectric material and an inner electrode coupled to an inner surface of the piezoelectric material to sandwich the piezoelectric material therebetween.

9. The piezoelectric sensor according to claim 8, wherein the inner electrode includes a plurality of inner sub-electrodes that are spaced apart by gaps from one another.

10. The piezoelectric sensor according to claim 8, wherein the outer electrode includes a plurality of outer sub-electrodes that are spaced apart by gaps from one another.

11. A piezoelectric sensor comprising:

the piezoelectric material according to claim 1; and

one or more output electrodes coupled to an outer surface of the piezoelectric material.

12. The piezoelectric sensor according to claim 11, wherein the one or more output electrodes includes a plurality of outer sub-electrodes that are spaced apart by gaps from one another.

13. The piezoelectric sensor according to claim 11, wherein the piezoelectric material includes an inner surface serving as a coupling surface to an article to be sensed.

14. A bicycle component comprising the piezoelectric sensor according to claim 7.

15. A bicycle crankshaft on which the piezoelectric sensor according to claim 7 is arranged.

16. A bicycle pedal shaft on which the piezoelectric sensor according to claim 7 is arranged.

17. A bicycle crank arm on which the piezoelectric sensor according to claim 7 is arranged.

28. An electric power supply comprising:

the piezoelectric material according to claim 1, wherein the piezoelectric material is configured to generate electric power when mechanical force is applied thereto; and

one or more electrodes coupled to the piezoelectric material to output the electric power.

18. A bicycle component comprising a ferroelectric film having power generating characteristics.

19. The bicycle component according to claim 18, wherein the ferroelectric film includes a mixture of ferroelectric particles and an adhesive resin.

20. The bicycle component according to claim 18, wherein a ratio of the ferroelectric particles relative to a total mass of the ferroelectric particles and the adhesive resin in the ferroelectric film is 40 mass % or greater and 98 mass % or less.

21. The bicycle component according to claim 18, comprising:

an insulation film formed on a surface of a main body of the bicycle component;

a first electrode formed on the insulation film;

the ferroelectric film connected to the first electrode; and

a second electrode connected to the ferroelectric film.

22. The bicycle component according to claim 18, comprising:

a shaft body;

an insulation film formed on a surface of the shaft body;

a plurality of output electrodes spaced apart by gaps from one another and arranged on the insulation film around the shaft body;

the ferroelectric film connected to the output electrodes, wherein the gaps between adjacent ones of the output electrodes are filled with the ferroelectric film; and

a common electrode connected to the ferroelectric film.

23. The bicycle component according to claim 22, wherein the shaft body is selected from a group consisting of a crankshaft, a crank arm, a pedal shaft, a frame, a handle, a stem, a hub axle, a hub shell, a spoke, a seat post, and a saddle rail.

24. The bicycle component according to claim 22, wherein

the ferroelectric film includes an inner surface and an outer surface that are substantially parallel to the shaft body, and

the output electrodes are in close contact with the inner surface of the ferroelectric film, and the common electrode is in close contact with the outer surface of the ferroelectric film.

25. The bicycle component according to claim 21, wherein the first electrode is configured to output an output signal to a signal processor in accordance with electric energy generated by the ferroelectric film.

26. The bicycle component according to claim 25, wherein the signal processor is operated using electric power generated by the ferroelectric film.

27. The bicycle component according to claim 25, wherein the signal processor includes a wireless unit that performs wireless communication.

29. A method for manufacturing a piezoelectric material, the method comprising:

sintering raw particles containing a ferroelectric;

pulverizing a sinter obtained in the sintering to obtain ferroelectric particles; and

mixing the ferroelectric particles and an adhesive resin so that a ratio of the ferroelectric particles relative to a total mass of the ferroelectric particles and the adhesive resin is 40 mass % or greater and 98 mass % or less.

30. The method for manufacturing a piezoelectric material according to claim 29, wherein an average particle diameter of the ferroelectric particles pulverized in the pulverizing is 2 μ

m or greater and 10 μ

m or less.

31. The method for manufacturing a piezoelectric material according to claim 29, wherein the sintering is conducted under a sintering temperature that is 1100°

C. or greater and 1200°

C. or less.