Ultrasonic flow switch

• US 9,671,264 B2
• Filed: 04/21/2016
• Issued: 06/06/2017
• Est. Priority Date: 05/14/2015
• Status: Active Grant

• Current Assignee: Keyence Corporation (Keyence)
• Original Assignee: Keyence Corporation (Keyence)
• Inventors: Kashima, Hiroshi
• Primary Examiner(s): Thompson, Jewel V
• Application Number:
  US15/134,404
• Publication Number:
  US 20160334252A1
• Time in Patent Office: 411 Days
• Field of Search: 7386127-86129
• CPC Class Codes: G01F 1/662 Constructional details
• CPC Class Codes: G01F 1/667 Arrangements of transducers for ultrasonic flowmeters; Circuits for operating ultrasonic flowmeters
• CPC Class Codes: G01F 15/14 Casings, e.g. of special material
• CPC Class Codes: G01F 15/18 Supports or connecting means for meters

Abstract

Provided is an ultrasonic flow switch which can be stably mounted on pipes. A casing part which integrally or independently holds the ultrasonic wave elements is mounted on an outer surface of the pipe by a clamp part. An acoustic couplant which is formed of a soft elastic body is pressed to an outer surface of the pipe such that at least one of the first and second ultrasonic wave elements is acoustically coupled to the pipe. A collapsing amount of the acoustic couplant at a portion where the collapsing amount of the acoustic couplant caused by the pipe is the largest is restricted by a collapsing amount restricting part.

Claims

1. An ultrasonic flow switch to output an ON/OFF signal based on a flow rate of a fluid in a pipe, the ultrasonic flow switch comprising:

a first ultrasonic wave element configured to transmit an ultrasonic wave to a fluid in a pipe;

a second ultrasonic wave element configured to receive the ultrasonic wave from the fluid in the pipe;

a calculator configured to calculate a flow rate of the fluid in the pipe based on an output signal from the second ultrasonic wave element;

an output part configured to output the ON/OFF signal based on the flow rate calculated by the calculator and a preset flow rate threshold value;

an element holder integrally or independently holding the first ultrasonic wave element and the second ultrasonic wave element;

a mounting member detachably mounted on an outer surface of the pipe, configured to hold the element holder; and

an acoustic contact medium formed of a soft elastic body, and arranged between at least one of the first and second ultrasonic wave elements and the pipe,

wherein the acoustic contact medium is pressed to the outer surface of the pipe such that the at least one ultrasonic wave element is acoustically coupled to the pipe in a state where the mounting member is mounted on the outer surface of the pipe and the element holder is held by the mounting member, and

the ultrasonic flow switch further comprises a collapsing amount restricting part which restricts a collapsing amount of the acoustic contact medium at a portion where the collapsing amount of the acoustic contact medium caused by the pipe is the largest.

2. The ultrasonic flow switch according to claim 1, wherein the soft elastic body includes polymer rubber or a gel-like substance.

3. The ultrasonic flow switch according to claim 1, wherein the collapsing amount restricting part restricts the collapsing amount of the acoustic contact medium caused by the pipe to 10% or more and 50% or less of a thickness of the acoustic contact medium in a state where the acoustic contact medium is not brought into contact with the outer surface of the pipe.

4. The ultrasonic flow switch according to claim 1, wherein the collapsing amount restricting part is provided between the element holder and the pipe, and restricts the collapsing amount of the acoustic contact medium by restricting a distance between the outer surface of the pipe and a portion of the element holder.

5. The ultrasonic flow switch according to claim 4, wherein the collapsing amount restricting part is detachably or integrally mounted on the element holder, and restricts the collapsing amount of the acoustic contact medium by being brought into contact with the outer surface of the pipe.

6. The ultrasonic flow switch according to claim 5, wherein the collapsing amount restricting part includes a screw member mounted on the element holder, and the screw member restricts the collapsing amount of the acoustic contact medium by being brought into contact with the outer surface of the pipe.

7. The ultrasonic flow switch according to claim 4, wherein the collapsing amount restricting part is arranged between the element holder and the outer surface of the pipe, and restricts the collapsing amount of the acoustic contact medium by being brought into contact with the element holder and the outer surface of the pipe.

8. The ultrasonic flow switch according to claim 1, wherein the collapsing amount restricting part is provided between the element holder and the mounting member, and restricts the collapsing amount of the acoustic contact medium by restricting a distance between a portion of the element holder and a portion of the mounting member.

9. The ultrasonic flow switch according to claim 8, wherein the collapsing amount restricting part is detachably or integrally mounted on one of the element holder and the mounting member, and restricts the collapsing amount of the acoustic contact medium by being brought into contact with the other of the element holder and the mounting member.

10. The ultrasonic flow switch according to claim 9, wherein the collapsing amount restricting part is integrally mounted on the mounting member.

11. The ultrasonic flow switch according to claim 8, wherein the collapsing amount restricting part is arranged between the element holder and the mounting member, and restricts the collapsing amount of the acoustic contact medium by being brought into contact with the element holder and the mounting member.

12. The ultrasonic flow switch according to claim 1, wherein the collapsing amount restricting part is mounted on the acoustic contact medium, and restricts the collapsing amount of the acoustic contact medium by restricting a distance between the outer surface of the pipe and a portion of the element holder.

13. The ultrasonic flow switch according to claim 1, wherein the acoustic contact medium is detachably or integrally mounted on the element holder.

14. The ultrasonic flow switch according to claim 13, further including a medium holding member which holds the acoustic contact medium in the element holder.

15. The ultrasonic flow switch according to claim 13, wherein the acoustic contact medium is bonded to the element holder by an adhesive member.

16. The ultrasonic flow switch according to claim 1, further including a fixing member which fixes the element holder to the mounting member, and

the mounting member and the element holder are configured such that an operation for mounting the mounting member on the pipe and an operation for fixing the element holder to the mounting member by the fixing member are performed from a common direction.

17. The ultrasonic flow switch according to claim 16, further including a display part which displays the flow rate calculated by the calculator and the threshold value,

wherein the display part is provided on the element holder such that the display part is viewable from the common direction.

18. The ultrasonic flow switch according to claim 16, further including a connecting part to which a connecting line for transmitting the ON/OFF signal outputted from the output part is connectable,

wherein the connecting part is provided to the element holder such that the connecting line is connectable to the connecting part from the common direction.

19. The ultrasonic flow switch according to claim 18, wherein the first and second ultrasonic wave elements acquire electric power through the connecting part.

20. The ultrasonic flow switch according to claim 1, wherein

the second ultrasonic wave element is further configured to transmit an ultrasonic wave to the fluid in the pipe;

the first ultrasonic wave element is further configured to receive the ultrasonic wave from the fluid in the pipe;

a calculator is configured to calculate a flow rate of the fluid in the pipe based on an output signal from the first ultrasonic wave element and the second ultrasonic wave element.