Liquid level detector

Patent metadata

Field	Value
Publication number	US-2016123791-A1
Application number	US-201414894554-A
Country	US
Kind code	A1
Filing date	Jun 3, 2014
Priority date	Jun 5, 2013
Publication date	May 5, 2016
Grant date	—

Abstract

A liquid level detector includes a casing that is fixed to a container and includes a first regulatory section and a second regulatory section which are opposed to each other in a gravity direction, a float that floats on the liquid surface and has its upward and downward displacement along the gravity direction restricted by contact with the first regulatory section or the second regulatory section, a magnet body that extends along the gravity direction and is held by the float to be displaced upward or downward in conformity with the liquid surface, and a switch mechanism that is held by the casing and is switched between its on-state and off-state when one magnet end face of the magnet body in its extending direction is displaced in the gravity direction beyond a switching plane. The casing is assumed to be disposed in a first or second position. The float is arranged between the first regulatory section and the second regulatory section with a specific bottom end section directed in the gravity direction regardless of the disposing position of the casing. A first distance from the switching plane to the first regulatory section and a second distance from the switching plane to the second regulatory section are both longer than a length from the one magnet end face to the bottom end section.

First claim

What is claimed is:

1 . A liquid level detector for detecting a level of a surface of liquid stored in a container, the detector comprising:
a casing that is fixed to the container and includes a first regulatory section and a second regulatory section which are opposed to each other in a gravity direction; a float that floats on the surface of liquid and has its upward and downward displacement along the gravity direction restricted by contact of the float with the first regulatory section or the second regulatory section; a magnet body that has a shape extending along the gravity direction and is held by the float to be displaced upward or downward in conformity with the surface of liquid; and a switch mechanism that is held by the casing, wherein:
when one magnet end face of the magnet body in its extending direction is displaced in the gravity direction beyond a predetermined virtual switching plane, the switch mechanism is switched from one to the other of its on-state and off-state;
the casing is assumed to be disposed in a first position where the first regulatory section is located further in the gravity direction than the second regulatory section, and to be disposed in a second position where the second regulatory section is located further in the gravity direction than the first regulatory section;
the float is arranged between the first regulatory section and the second regulatory section in a position where a specific bottom end section of the float is directed in the gravity direction regardless of whether the casing is disposed in the first position or in the second position; and
a first distance from the switching plane to the first regulatory section and a second distance from the switching plane to the second regulatory section are both longer than a length from the one magnet end face to the bottom end section.

2 . The liquid level detector according to claim 1 , wherein a length from a top end section of the float located on an opposite side of the magnet body from the bottom end section to the one magnet end face is shorter than the first distance and the second distance.

3 . The liquid level detector according to claim 1 , wherein the one magnet end face is arranged at a center of the float in the gravity direction.

4 . The liquid level detector according to claim 1 , wherein the first distance is substantially equal to the second distance.

5 . The liquid level detector according to claim 1 , wherein:
a gap formed between a top end section of the float that is located on an opposite side of the magnet body from the bottom end section and one of the first regulatory section and the second regulatory section that is opposed to the top end section in a state where the one magnet end face is located on the switching plane is defined as an upper gap; and the upper gap is shorter than a size of the magnet body along the gravity direction.

6 . The liquid level detector according to claim 1 , wherein:
the casing includes a partition wall and an accommodating chamber that is defined by the partition wall to accommodate the float; and the partition wall includes at least one communication hole, which communicates between an inside and outside of the accommodating chamber, on each of both sides of the switching plane.

7 . The liquid level detector according to claim 1 , wherein:
the magnet body is retained at a position shifted downward from a center of the float in the gravity direction; and when the one magnet end face located on an upper side of the magnet body is displaced in the gravity direction beyond the switching plane, the switch mechanism is switched from its on-state to off-state.

8 . The liquid level detector according to claim 1 , wherein:
the magnet body is retained at a position shifted upward from a center of the float in the gravity direction; and when the one magnet end face located on a lower side of the magnet body is displaced in the gravity direction beyond the switching plane, the switch mechanism is switched from its off-state to on-state.

Assignees

• Denso Corp

Inventors

• Yasuda Atsushi

Classifications

• G01F23/62 Primary

  using magnetically actuated indicating means · CPC title

• G01F23/72 Primary

  using magnetically actuated indicating means · CPC title

• G01F23/74

  for sensing changes in level only at discrete points · CPC title