JPH0317216Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flow rate detector for automatically controlling related equipment by detecting the flow rate of fluid, especially water, and sending an electrical signal.

Conventionally, in order to detect the flow rate of a fluid, there is a method in which a rotary impeller with a magnet attached is arranged in the fluid flow path, and the rotation speed of this magnet is detected by a magnetic sensor such as a Hall element. The configuration of the flow rate detector will be explained based on FIG. 3.

1 is a cylindrical flow rate detector body with an inlet 2 at the bottom and an outlet 3 at the upper side;
An impeller 5 is rotatably housed in a working chamber 4 formed therein below the outlet 3. A large number of blades 6 are provided on the impeller 5 obliquely to the axis of the inlet 2, and a rotating shaft 7 is attached to the impeller 5 so as to protrude from the impeller 5 in the vertical direction. Reference numeral 8 denotes a rectifier plate placed at the bottom of the working chamber 4, with water holes 9 around it.
is divided into parts, and a support part 10 for supporting the lower end of the direct rotation shaft 7 is provided in the center. Also, rotating shaft 7
The upper part of the main body 1 passes through a case 11 installed in the main body 1, and a permanent magnet 12 is attached to the upper end. Reference numeral 19 denotes a magnetic sensor such as a Hall element, which receives changes in the magnetic field due to the rotation of the magnet 12 and generates pulses according to the number of rotations. A vent 11a is provided in the upper side wall of the case 11 at a position facing the outflow port 3.
Further, the lower end of the part of the case 11 through which the rotating shaft 7 is inserted is made to protrude into the working chamber 4, so that the support tube 11b can be inserted into the case 11.
It is integrally formed with. The chamber 13 housing the magnet 12 communicates with the working chamber 4 at its bottom through several through holes 15 provided in the partition wall 14 around the part of the case 11 through which the rotating shaft 7 is inserted.
includes a partition wall 14, a side wall 16 that stands up in a cylindrical shape on the partition wall 14, and a rotating shaft 7 that closes the upper surface of the side wall 16.
It is partitioned by an upper wall 17 that supports the upper end.

In this configuration, when a water flow occurs, the impeller 5 is rotated by the water flow, the magnet 12 is rotated, and the magnetic sensor 19 emits a pulse according to the rotation speed.

By the way, since it is not possible to provide a sealing gasket such as an O-ring which would create a large resistance to the rotation of the shaft at the insertion portion where the rotation speed is 7, it is inevitable that water will enter the chamber 13 through the gap around the shaft 7. Therefore, in order to prevent water from accumulating in the chamber 13 and freezing, a through hole 15 is provided to drain water from this hole, but even if the working chamber 4 is drained, the through hole 15 There was a problem that a water film was formed due to surface tension in the chamber 13, and the water in the chamber 13 froze, making it inoperable.

Therefore, the present invention has been made to solve this problem, by forming a groove 18 of an appropriate width in the vertical direction from the upper end of the side wall 16, and communicating the lower end of the groove 18 with one of the through holes 15a. It is something that According to the configuration of the present invention, the opening area of the through hole 15a is substantially expanded by the groove 18, and the water accumulated in the chamber 13 forms a water film in the portion of the through hole 15a. 15a and falls into the working chamber 4 due to its own weight. In this way, the water in the chamber 13 is completely drained, so that there is no possibility that the accumulated water will freeze in the winter and make the detection operation impossible.

In this way, according to the present invention, water does not drain out due to the water film generated during drainage, causing freezing and malfunction, and, for example, when using a flow rate detector for a water heater, it can be reused immediately. This is a highly practical idea that solves the inconvenience of not being able to do it.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of a main part showing an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1, and FIG. 3 is a general vertical cross-sectional view showing a conventional example. 1...Main body, 2...Inflow port, 3...Outflow port, 4
... Working chamber, 5 ... Impeller, 7 ... Rotating shaft, 12
... Permanent magnet, 13 ... Chamber, 14 ... Bulkhead, 1
5, 15a...Through hole, 16...Side wall, 18...
groove.

Claims (1)

[Scope of utility model registration request] In the main body, which has an inlet at the bottom and an outlet at the upper side, an operating chamber housing the impeller and a chamber housing the permanent magnet are provided above the working chamber via a partition. and a permanent magnet are attached to a rotating shaft penetrating the partition wall, and an appropriate number of through holes are provided in the partition wall to communicate the working chambers with the other chambers. A flow rate detector characterized in that a groove is formed in the vertical direction in a side wall forming a chamber, and a lower end of the groove is communicated with any of the through holes.