Liquid surface position detection device

• US 10,359,307 B2
• Filed: 03/14/2016
• Issued: 07/23/2019
• Est. Priority Date: 03/30/2015
• Status: Active Grant

• Current Assignee: Nippon Seiki Company Limited
• Original Assignee: Nippon Seiki Company Limited
• Inventors: Ichimura, Masatoshi, Suzuki, Hiroyuki
• Primary Examiner(s): Rogers, David A
• Application Number:
  US15/560,130
• Publication Number:
  US 20180100756A1
• Time in Patent Office: 1,226 Days
• CPC Class Codes: B06B 1/0644 using a single piezoelectric element B06B1/0688 takes precedence
• CPC Class Codes: G01F 23/22 by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water involving the use of floats G01F23/30
• CPC Class Codes: G01F 23/2962 Measuring transit time of reflected waves
• CPC Class Codes: G01F 23/2965 Measuring attenuation of transmitted waves
• CPC Class Codes: G01F 23/2968 Transducers specially adapted for acoustic level indicators

Abstract

A liquid-surface position detection device includes: a propagation body being disposed in a container immersed in a liquid and propagating surface waves; a vibration generation and detection means imparting vibrations to the propagation body and including a piezoelectric element detecting reflected surface waves; and a position detection means calculating the liquid surface position from the reflection time of the surface waves. The propagation body is made of a resin material and provided integrally, at the upper part thereof, with an element accommodating part which accommodates the piezoelectric element. The element accommodating part includes a bottom surface section formed so that a portion thereof juts out from a main surface forming the surface of the propagation body. The piezoelectric element is disposed so that a portion thereof juts out from the main surface, and to apply vibrations to the main surface in the vertical direction via the bottom surface section.

Claims

1. A liquid surface position detection device, comprising:

a propagation body which is provided in a container so as to be immersed in a liquid and through which surface waves propagate;

a vibration generation and detection means which includes a piezoelectric element which is provided in the propagation body, configured to apply vibrations to the propagation body, and configured to detect reflected surface waves; and

a position detection means configured to calculate a liquid surface position by measuring reflection time of the surface waves from a signal detected by the piezoelectric element, wherein

the propagation body is made of a resin material, and integrally includes, at the upper part thereof, an element accommodating part which accommodates the piezoelectric element,

the element accommodating part includes a bottom surface part formed so that a portion thereof juts out of a main surface which forms a surface of the propagation body, and

the piezoelectric element is disposed so that a portion thereof juts out of the main surface, and so as to apply vibrations to the main surface in a direction orthogonal to the main direction via the bottom surface part.

2. The liquid surface position detection device according to claim 1, wherein

the element accommodating part, a spacer is disposed via an elastic member on the piezoelectric element, and

the piezoelectric element is pressed against the bottom surface part with the spacer being urged by a pressing member.

3. The liquid surface position detection device according to claim 1, wherein

the element accommodating part includes a substrate accommodating part which is formed to communicate with an accommodation space of the element accommodating part, and which accommodates a circuit substrate, and

the substrate accommodating part integrally includes a flange attached to the container.

4. The liquid surface position detection device according to claim 3, wherein

the element accommodating part, a spacer is disposed via an elastic member on the piezoelectric element, and

the piezoelectric element is pressed against the bottom surface part with the spacer being urged by a pressing member.

5. The liquid surface position detection device according to claim 3, wherein the substrate accommodating part is provided separately from the element accommodating part and is made of a material different from that of the element accommodating part.

6. The liquid surface position detection device according to claim 5, wherein

the element accommodating part, a spacer is disposed via an elastic member on the piezoelectric element, and

the piezoelectric element is pressed against the bottom surface part with the spacer being urged by a pressing member.