JPS5944569B2 - electronic water meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronic water meter that electronically measures the amount of water used, and particularly relates to an electronic water meter that electronically measures the amount of water used. The meter is attached at a certain angle to the rotation axis of the impeller, thereby reducing the size of the meter and improving measurement accuracy.

FIG. 1 is a side sectional view showing an example of a conventional electronic water meter, in which 1 is a water meter case, 2 is an impeller that rotates in proportion to the amount of water flowing inside the water meter case 1; 3
, 3' is a permanent magnet mounted to rotate integrally with the impeller 2, and 4 is a magnetic sensor that generates an electric pulse in response to the rotation of the impeller 2 in response to the rotation of the permanent magnets 3 and 3'. ,
5 is an electronic counter section for counting electric pulses from the magnetic sensor 4; 6 is, for example, a liquid crystal display section for displaying the value counted by the electronic counter section 5; T is an electronic counter section 5;
and a power supply unit that supplies power voltage to the display unit 6; 8 is a container that watertightly accommodates the magnetic sensor 4 to the power supply unit T; the container 8 is watertightly coupled to the water meter case 1 via a packing 9; ing.

Therefore, the above-mentioned conventional electronic water meter has a permanent magnet 3,
As shown in Fig. 2, the magnetic flux from 3' extends for a long time substantially parallel to the rotation axis Ax of the impeller 2, exerts a magnetic effect on iron-based parts in the electronic circuit, and brakes the impeller. especially,
This effect is large in the micro flow range, and has become one of the major causes of measurement errors in the micro flow range. In order to avoid this drawback, it is best to avoid placing iron-based members near the magnetic sensor 4, but if you try to place iron-based members away from the magnetic sensor, the structure of the magnetic sensor side will become larger. Therefore, it was difficult to downsize the measuring instrument. In addition, Figure 3 shows
This is a diagram schematically showing a magnetic path when one permanent magnet is used instead of the example using two permanent magnets as described above; It is easy to understand that it also has the drawbacks mentioned above.
The present invention has been made in order to eliminate the drawbacks of the prior art as described above, and as shown in FIG. The impeller 2 is arranged at a certain angle θ (see FIGS. 5 and 6) with respect to the rotation axis Ax of the impeller 2.

In this way, when a permanent magnet is arranged at a certain angle to the rotation axis of the impeller, the lines of magnetic force emitted from the permanent magnet are as shown in Figure 5 or 6 (Figure 6 shows the case where there is only one permanent magnet). As shown in ), the impeller becomes flat in the direction of the rotation axis Ax, and the length L in the rotation axis direction becomes shorter, and the iron-based member on the magnetic sensor side affects the rotation of the impeller accordingly. It can be arranged close to the permanent magnet of the impeller without giving any stress, thus making it possible to reduce the size of the meter and at the same time improve the metering accuracy. FIG. 7 is a schematic configuration diagram of main parts for explaining another embodiment of the present invention, and as shown in the figure,
Permanent magnets 3, 3' integrally installed in the impeller 2 are arranged at a certain angle θ' (0, <θ7≦90) with respect to the rotation axis of the impeller 2, and the permanent magnets 3, 3' Magnetic sensors 4, 4' are arranged opposite to 3', and magnetic sensors 4, 4'
A magnetic focusing iron piece 10 is provided in the magnetic path that passes through both of the permanent magnets 3 and 3' to further flatten the magnetic field from the permanent magnets 3 and 3'.

Therefore, according to this embodiment, the distance that the lines of magnetic force from the permanent magnets 3, 3' penetrate into the magnetic sensor side is further shortened,
Therefore, the iron-based member on the magnetic sensor side can be placed close to the permanent magnet of the impeller without affecting the rotation of the impeller, which reduces the size of the instrument and reduces measurement errors. can be made smaller.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view for explaining an example of a conventional electronic water meter, and FIGS. 2 and 3 are schematic magnetic path diagrams for explaining the magnetic path of a conventional electronic water meter. FIG. 4 is a side sectional view for explaining one embodiment of the electronic water meter according to the present invention, and FIGS. 5 and 6 are schematic diagrams for explaining the magnetic path of the electronic water meter according to the present invention. The magnetic path diagram, FIG. 7, is a schematic configuration diagram of main parts for explaining another embodiment of the electronic water meter according to the present invention. 1... Water meter case, 2... Impeller, 3, 3'-... Permanent magnet, 4, 4'...
...Magnetic sensor, 10... Magnetic focusing member.

Claims (1)

[Scope of Claims] 1. A permanent magnet that rotates integrally with an impeller that rotates in accordance with the amount of water used, and a magnetic sensor that detects rotation of the impeller in response to the permanent magnet. An electronic water meter having an electronic circuit that counts and displays electrical pulse signals from the magnetic sensor, characterized in that the permanent magnet is arranged at a certain angle with respect to the rotation axis of the impeller. Electronic water meter. 2. A permanent magnet integrally attached to an impeller that rotates in accordance with the amount of water used, a magnetic sensor that detects the rotation of the impeller in response to the permanent magnet, and electricity from the magnetic sensor. In the electronic water meter, the permanent magnet is arranged at a certain angle with respect to the rotation axis of the impeller, and a magnetic field passing through the permanent magnet and the magnetic sensor is provided. An electronic water meter characterized by having a magnetic focusing member disposed in a passage.