Load sensor, load detector including load sensor, and method for detecting load

Patent metadata

Field	Value
Publication number	US-9784627-B2
Application number	US-201414531595-A
Country	US
Kind code	B2
Filing date	Nov 3, 2014
Priority date	Nov 27, 2013
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

A load sensor includes a core having a hollow part provided therein and containing magnetic material and a coil attached to the core. A magnetic path along which a magnetic flux generated by a current flowing in the coil is formed along a circumference direction of the hollow part. The core has a load-receiving portion that receives a load at a surface of the core located in a crossing direction crossing a plane along which the magnetic path is formed.

First claim

What is claimed is:

1. A load sensor comprising:
a core having a hollow part provided therein, the core comprising magnetic material; and
a coil attached to the core;
a first plate and a second plate that sandwich the core; and
an elastic body positioning the first plate and the second plate, the elastic body comprising material having an elasticity value smaller than an elasticity value of the core,
wherein a magnetic path along which a magnetic flux generated by a current flowing in the coil is formed along a circumference direction of the hollow part,
wherein the core has a load-receiving portion that receives a load at a surface of the core located in a crossing direction crossing a plane along which the magnetic path is formed, and
wherein the first plate and the second plate sandwiches the core in the crossing direction.

2. The load sensor according to claim 1 ,
wherein the core includes an attachment part having the coil attached thereto and a part which has the load-receiving portion and which is different from the attachment part,
wherein the attachment part of the core has a size in the crossing direction is smaller than a size of the part of the core which has the load-receiving portion and which is different from the attachment in the crossing direction, and
wherein the size of the attachment part in the crossing direction allows the coil to fit within a width of the part of the core which has the load-receiving portion and which is different from the attachment in the crossing direction.

3. The load sensor according to claim 2 , further comprising a protecting part that covers the coil from a side of the load-receiving portion in the crossing direction.

4. The load sensor according to claim 1 , further comprising a structural component that is disposed between the first plate and the second plate, and positions the core.

5. The load sensor according to claim 4 ,
wherein the structural component includes a positioning hole passing through the structural component in the crossing direction, and
wherein the core is disposed in the positioning hole.

6. The load sensor according to claim 4 , wherein the structural component comprises a board having a circuit mounted thereto.

7. The load sensor according to claim 6 , further comprising an insulator that is disposed between the board and an outer housing including at least one of the first plate and the second plate, the insulator electrically insulating the board from the outer housing.

8. The load sensor according to claim 6 , wherein the board includes a plurality of laminated layers and a conductor that is provided at one of the plurality of laminated layers, and the conductor constitutes the coil.

9. The load sensor according to claim 1 , further comprising a shield that comprises metal and covers at least a part of the core.

10. The load sensor according to claim 1 , wherein the core and the coil are disposed to form an open magnetic path when the current flows through the coil.

11. The load sensor according to claim 1 , wherein the core and the coil are disposed to form a closed magnetic path when the current flows through the coil.

12. A load detector comprising:
the load sensor according to claim 1 ; and
a detection circuit that detects, based on a change in an inductance of the coil, the load applied to the load-receiving part.

13. A load detector comprising:
the load sensor according to claim 1 ; and
a detection circuit that detects, based on a change in a conductance of the coil, the load applied to the load-receiving part.

14. A load detecting method, comprising:
supplying a current to the coil of the load sensor according to claim 1 ; and
detecting, based on a change in an inductance of the coil, the load applied to the load-receiving portion in the crossing direction.

15. A load detecting method, the method comprising:
supplying a current to the coil of the load sensor according to claim 1 ; and
detecting, based on change in a conductance of the coil, the load applied to the load-receiving portion in the crossing direction.

16. The load sensor according to claim 1 , wherein the core is configured to receive a load in a direction along the crossing direction.

17. The load sensor according to claim 1 , wherein a space is provided around the coil in the crossing direction so that the load is not applied to the coil.

18. The load sensor according to claim 1 ,
wherein the core includes an attachment part having the coil attached thereto,
wherein the attachment part of the core has a thickness in the crossing direction smaller than a thickness of a remaining part of the core in the crossing direction so that the load is not applied to the coil, and
wherein the thickness of the attachment part in the crossing direction allows the coil to fit within the thickness of the remaining part of the core.

19. A load sensor comprising:
a core having a hollow part provided therein, the core comprising magnetic material;
a coil attached to the core; and
a bobbin attached to a part of the core,
wherein a magnetic path along which a magnetic flux generated by a current flowing in the coil is formed along a circumference direction of the hollow part,
wherein the core has a load-receiving portion that receives a load at a surface of the core located in a crossing direction crossing a plane along which the magnetic path is formed,
wherein the core has a gap provided in a part of the core in the circumferential direction,
wherein the bobbin is attached to the core to cover the gap, and
wherein the coil includes a lead wire wound around the core via the bobbin.

20. A load sensor comprising:
one or more detecting units each including a core and a coil magnetically coupled to the core, the core being made of magnetic material;
a first plate and a second plate that sandwich the one or more detecting units in a detecting direction between the first plate and the second plate; and
an elastic body positioning the first plate and the second plate, the elastic body comprising material having an elasticity value smaller than an elasticity value of the core,
wherein the one or more detecting units are configured to receive a load applied from the first plate and the second plate in the detecting direction.

21. The load sensor according to claim 20 ,
wherein the one or more detecting units comprise a plurality of detecting units each including the core and the coil, and
wherein the plurality of detecting units are arranged along a plane perpendicular to the detecting direction.

22. The load sensor according to claim 21 , wherein the plurality of detecting units are arranged symmetrically to each other with respect to a reference line on the plane or with respect to a reference point on the plane.

23. The load sensor according to claim 21 ,
wherein each of the first plate and the second plate has an aperture therein that passes through respective one of the first plate and the second plate in the detecting direction, and
wherein the plurality of detecting units are arranged around the aperture.

24. The load sensor according to claim 21 , wherein each of the plurality of detecting units is disposed corresponding to respective one of two or more detection positions out of a plurality of detection positions.

25. The load sensor according to claim 21 , wherein the core of each of the plurality of detecting units has an equal

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Saito Fumitaka
• Niwa Masahisa

Classifications

• H01L41/125

  Electricity · mapped topic

• G01L1/125 Primary

  by using magnetostrictive means (magnetostrictive sensors H10N35/101) · CPC title

• H10N35/101

  with mechanical input and electrical output, e.g. generators, sensors · CPC title