Force sensor with strain gauge attached to flexible wall of a main beam of the force sensor

Patent metadata

Field	Value
Publication number	US-11022506-B2
Application number	US-201716463892-A
Country	US
Kind code	B2
Filing date	Nov 28, 2017
Priority date	Nov 28, 2016
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A force sensor has a first end portion (1), a second end portion (2), a parallel-guiding mechanism (3), a beam (4), and a strain gauge (5). The parallel-guiding mechanism (3) connects the first end portion (1) to the second end portion (2). A main beam (43) of the beam has a flexible wall (435) and a rigid wall (432). A first connecting part (41) connects the flexible wall to the first end portion, and a second connecting part (42) connects the rigid wall to the second end portion. The strain gauge (5) is fixed to the flexible wall (435). The force sensor can measure a relatively small force.

First claim

The invention claimed is:

1. A force sensor, comprising:
a first end portion;
a second end portion;
a parallel-guiding mechanism that connects the first end portion to the second end portion;
a strain gauge; and
a beam comprising:
a main beam having a flexible wall, to which the strain gauge is attached, and a rigid wall;
a first connecting part that connects the first end portion to the flexible wall of the main beam; and
a second connecting part that connects the second end portion to the rigid wall of the main beam;
wherein the main beam further has a cavity to accept arrangement of the strain gauge therein and a cover plate for sealing the cavity in a welded manner.

2. The force sensor of claim 1 , further comprising:
a protrusion on an outer side of the flexible wall that is connected to the first connecting part; and
two grooves positioned where the protrusion intersects the first connecting part.

3. The force sensor of claim 1 , wherein the flexible wall is formed by outwardly recessing the main beam.

4. The force sensor of claim 1 , wherein the strain gauge is arranged above and/or below the position where the first connecting part intersects the flexible wall.

5. The force sensor of claim 1 , wherein the first connecting part is a rigid beam, and the second connecting part is a flexible beam.

6. The force sensor of claim 5 , wherein the second connecting part comprises a horizontal extension, and a flexible connecting section on the second connecting part is located thereon.

7. The force sensor of claim 5 , wherein the second connecting part comprises a horizontal extension and a vertical extension, and a flexible connecting section on the second connecting part is located on the vertical extension.

8. The force sensor of claim 1 , wherein:
the first end portion operates as a fixed portion, and the second end portion operates as a load-receiving portion.

9. The force sensor of claim 1 , wherein:
the strain gauge is arranged in a region close to where the first connecting part intersects the flexible wall.

10. A force sensor, comprising:
a first end portion;
a second end portion;
a parallel-guiding mechanism that connects the first end portion to the second end portion;
a beam comprising:
a main beam having a rigid wall and a flexible wall with a protrusion on an outer side of the flexible wall;
a first connecting part that connects the first end portion to the protrusion;
a second connecting part that connects the second end portion to the rigid wall; and
two grooves positioned where the protrusion intersects the first connecting part; and

a strain gauge that is fixed to the flexible wall.

11. A force sensor, comprising:
a first end portion;
a second end portion;
a parallel-guiding mechanism that connects the first end portion to the second end portion;
a beam comprising:
a main beam having a flexible wall and a rigid wall;
a rigid beam that connects the first end portion to the flexible wall of the main beam; and

a flexible beam that connects the second end portion to the rigid wall of the main beam, the flexible beam comprising a horizontal extension and a vertical extension with a flexible connecting section on the vertical extension; and
a strain gauge that is fixed to the flexible wall.

Assignees

• Mettler Toledo Changzhou Prec Instrument Ltd
• Mettler Toledo Changzhou Measurement Technology Ltd
• Mettler Toledo Int Trading Shanghai Co Ltd

Inventors

• Wang Jianwen
• Xu Yujun
• Wang Wei

Classifications

• G01L1/22 Primary

  using resistance strain gauges · CPC title

• G01L1/2243 Primary

  the supports being parallelogram-shaped · CPC title

• G01G3/1412

  the supports being parallelogram shaped · CPC title

• G01G21/244

  combined with flexure-plate fulcrums (flexure-plate fulcrums G01G21/07) · CPC title