Mass measurement device

Patent metadata

Field	Value
Publication number	US-10352756-B2
Application number	US-201515511008-A
Country	US
Kind code	B2
Filing date	Sep 17, 2015
Priority date	Sep 19, 2014
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A mass measurement device comprises a force sensor, a hose, a base part, an article-holding part, and a computation unit. The force sensor has a fixed end and a free end, and outputs a sensing signal in accordance with the magnitude of a force in a sensitivity direction. The hose is configured to pass suctioned air through it. The fixed end is fixed to the base part. The article-holding part is fixed to the free end, one end of the hose is connected to the article-holding part, and the article-holding part holds an article by air suction. The computation unit computes the mass of the article based on the sensing signal.

First claim

The invention claimed is:

1. A mass measurement device comprising:
a force sensor, which has a fixed end and a free end, and outputs a sensing signal in accordance with a magnitude of a force in a sensitivity direction;
a suction channel configured to pass suctioned air through the suction channel;
a base part to which the fixed end is fixed;
an article-holding part fixed to the free end, one end of the suction channel being connected to the article-holding part, and the article-holding part being configured to hold an article due to the suctioned air; and
a computation unit configured to compute a mass of the article based on the sensing signal;
wherein the force sensor and the suction channel are disposed so that an x-axis directional component of a force exerted on the article-holding part by the suction channel is the smallest among the x-axis directional component, a y-axis directional component, and a z-axis directional component, where the sensitivity direction is an x-axis direction, a direction orthogonal to the x-axis direction is a y-axis direction, and a direction orthogonal to both the x-axis direction and the y-axis direction is a z-axis direction.

2. The mass measurement device according to claim 1 , wherein
the suction channel is disposed so as to pass through the base part.

3. The mass measurement device according to claim 1 , wherein
the suction channel has a hose disposed in a yz plane, which expands in the y-axis direction and the z-axis direction.

4. The mass measurement device according to claim 1 , wherein
the suction channel has a rigid pipe disposed in a yz plane, which expands in the y-axis direction and the z-axis direction.

5. The mass measurement device according to claim 1 , wherein
the suction channel has a pair of rigid pipes separated by a gap.

6. The mass measurement device according to claim 1 , wherein
the suction channel has a pair of rigid pipes having different diameters, one pipe being inserted into the other pipe.

7. The mass measurement device according to claim 1 , wherein
the force exerted on the article-holding part by the suction channel is generated by pulsation of the suction channel during air suction, or by movement of the suction channel caused by a start or an end of air suction.

8. The mass measurement device according to claim 1 , further comprising:
a robot that causes the base part to move.

9. The mass measurement device according to claim 1 , further comprising:
an acceleration sensor that outputs an acceleration signal in accordance with a magnitude of an acceleration of the article-holding part in the sensitivity direction;
the computation unit configured to compute the mass of the article based on:
the sensing signal outputted by the force sensor when the base part moves in the sensitivity direction; and
the acceleration signal outputted by the acceleration sensor when the base part moves in the sensitivity direction.

10. The mass measurement device according to claim 1 , wherein
the sensitivity direction is a horizontal direction.

11. The mass measurement device according to claim 1 , wherein
the sensitivity direction is a vertical direction.

12. The mass measurement device according to claim 1 , wherein
the force sensor is a strain gauge-type load cell.

13. The mass measurement device according to claim 1 , further comprising:
a vacuum pump in communication with the suction channel.

14. The mass measurement device according to claim 1 , wherein the suction channel has a hose that travels in the z-axis direction and attaches to the article-holding part in the y-axis direction.

Assignees

• Ishida Seisakusho

Inventors

• Suzuki Akihito
• Nakatani Makoto
• Minamino Shizuo

Classifications

• G01L1/2287

  constructional details of the strain gauges (adjustable resistors H01C10/00) · CPC title

• B65B61/28

  for discharging completed packages from machines · CPC title

• G01G23/01

  Testing or calibrating of weighing apparatus · CPC title

• B65G47/902

  provided with drive systems incorporating rotary and rectilinear movements · CPC title

• G01G19/18 Primary

  having electrical weight-sensitive devices · CPC title