Load sensor and load detecting device

Patent metadata

Field	Value
Publication number	US-9804042-B2
Application number	US-201615040122-A
Country	US
Kind code	B2
Filing date	Feb 10, 2016
Priority date	Mar 11, 2015
Publication date	Oct 31, 2017
Grant date	Oct 31, 2017

Abstract

A load sensor is provided with a seat mounting hole between both end parts of a rectangular plate-like main body portion of a load receiving member. A plurality of strain detecting elements the resistance value of each of which changes depending on the amount of strain of the main body portion are disposed around the seat mounting hole. In plan view of the load receiving member, the center point of the seat mounting hole is offset from the center point of the arrangement of the plurality of strain detecting elements toward a part of the load receiving member that has relatively high rigidity.

First claim

What is claimed is:

1. A load sensor comprising:
a plate-like load receiving member having side body mounting holes formed at respective sides of the plate-like load receiving member, a seat mounting hole formed at a center position between the side body mounting holes, a pair of supporting portions and a load receiving portion provided between the pair of supporting portions; and
a plurality of strain detecting elements disposed around the load receiving portion, the resistance value of each of the respective plurality of strain detecting elements changing depending on the amount of strain of the load receiving member,
wherein in plan view of the load receiving member, the center point of the load receiving portion is offset from the center point of the arrangement of the plurality of strain detecting elements toward a part of the load receiving member that has relatively high rigidity.

2. The load sensor according to claim 1 ,
wherein the load receiving member is formed in a substantially T-shape in plan view, the substantially T-shape having a rectangular plate-like main body portion and a protruding portion protruding from the middle of a long side of the main body portion in a direction perpendicular to the long side,
the pair of supporting portions are provided in both longitudinal end parts of the main body portion, and
in plan view of the load receiving member, the center point of the load receiving portion is offset from the center point of the arrangement of the plurality of strain detecting elements toward the protruding portion.

3. The load sensor according to claim 1 , wherein the plurality of strain detecting elements are disposed symmetrically with respect to a line passing through the center point of the arrangement and parallel to a direction in which the pair of supporting portions are opposed to each other.

4. The load sensor according to claim 1 , wherein the plurality of strain detecting elements are disposed symmetrically with respect to a line passing through the center point of the arrangement and perpendicular to a direction in which the pair of supporting portions are opposed to each other.

5. The load sensor according to claim 3 , wherein the plurality of strain detecting elements are disposed symmetrically with respect to a line passing through the center point of the arrangement and perpendicular to a direction in which the pair of supporting portions are opposed to each other.

6. A load sensor comprising:
a plate-like load receiving member having side body mounting holes formed at respective sides of the plate-like load receiving member, a seat mounting hole formed at a center position between the side body mounting holes, a pair of supporting portions and a load receiving portion provided between the pair of supporting portions; and
a plurality of strain detecting elements disposed around the load receiving portion, the resistance value of each of the respective plurality of strain detecting elements changing depending on the amount of strain of the load receiving member,
wherein the plurality of strain detecting elements form four resistance units, and a first circuit part in which two of the four resistance units are connected in series and a second circuit part in which the other two of the four resistance units are connected in series are connected in parallel to form a Wheatstone bridge circuit,
the first circuit part is disposed between one of the pair of supporting portions and the load receiving portion,
the second circuit part is disposed between the other of the pair of supporting portions and the load receiving portion,
in a state where no load is applied to the load receiving member, the ratio of the resistance value of the positive-side resistance unit to the resistance value of the negative-side resistance unit in the first circuit part is set smaller than the ratio of the resistance value of the positive-side resistance unit to the resistance value of the negative-side resistance unit in the second circuit part, and
in plan view of the load receiving member, the center point of the load receiving portion is offset from the center point of the arrangement of the plurality of strain detecting elements toward the second circuit part.

7. The load sensor according to claim 6 , wherein in plan view of the load receiving member, the center point of the load receiving portion is also offset from the center point of the arrangement of the plurality of strain detecting elements toward a part of the load receiving member that has relatively high rigidity.

8. The load sensor according to claim 6 , wherein the plurality of strain detecting elements are disposed symmetrically with respect to a line passing through the center point of the arrangement and parallel to a direction in which the pair of supporting portions are opposed to each other.

9. The load sensor according to claim 6 , wherein the plurality of strain detecting elements are disposed symmetrically with respect to a line passing through the center point of the arrangement and perpendicular to a direction in which the pair of supporting portions are opposed to each other.

10. The load sensor according to claim 8 , wherein the plurality of strain detecting elements are disposed symmetrically with respect to a line passing through the center point of the arrangement and perpendicular to a direction in which the pair of supporting portions are opposed to each other.

11. A load detecting device comprising the load sensor according to claim 1 and a load detecting portion that detects the load applied to the load receiving member based on the output of the load sensor.

12. A load detecting device comprising the load sensor according to claim 6 and a load detecting portion that detects the load applied to the load receiving member based on the output of the load sensor.

Assignees

• Alps Electric Co Ltd

Inventors

• Saito Mitsuru
• Sekine Mikio

Classifications

• G01L1/2262

  involving simple electrical bridges · CPC title

• B60N2/002

  Seats provided with an occupancy detection means mounted therein or thereon (detection means responsive to presence or absence of children B60N2/266) · CPC title

• G01L1/2206 Primary

  Special supports with preselected places to mount the resistance strain gauges; Mounting of supports · CPC title

• B60R21/0152

  using strain gauges · CPC title

• B60N2210/42

  Strain gauges · CPC title