JPS628488Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention optically detects the change in the position of the elastic diaphragm due to the magnetic attraction between a magnetic slit disk that is linked to the rotation from the rotor of a positive displacement flowmeter, and a magnet provided on the elastic diaphragm. The present invention relates to an optical pulse detector that detects optical pulses.

In positive displacement flowmeters, when detecting pulses proportional to the flow rate, a reed switch is actuated by a magnet embedded in the rotor, or a slit with a notch or opening in a concentric circle according to the number of emitted pulses is used. A flow rate transmitter is used in which a disk is connected to an output shaft from a rotor, and a high frequency induced magnetic field is applied to the slit disk intermittently to emit a pulse proportional to the flow rate. By the way, these conventional devices use electricity as their driving source, so if they are used in oil factories that handle highly flammable fluids, they must be constructed to be explosion-proof, which not only makes the configuration complicated but also However, it also had the disadvantage of being expensive.

The purpose of this invention is to solve the above drawbacks,
An object of the present invention is to provide an optical flow rate transmitter that can be safely used even in places where highly flammable or corrosive fluids are handled.

Next, the configuration of the present invention will be explained based on an embodiment shown in the drawings. In the figure, 1 is an output shaft that transmits rotation from a rotor (not shown) of a positive displacement flowmeter;
2 is a bearing, and 3 is a magnetic slit disk that is interlocked with the output shaft 1, and a cutout or a through hole is provided near the periphery of the disk. Reference numeral 4 denotes an elastic diaphragm such as a diaphragm, the periphery of which is stretched between the casings 5 and 6. Reference numeral 7 denotes a magnet, which is fixed approximately at the center of the elastic diaphragm on the side where the magnetic slit disk is provided.
Reference numeral 8 denotes an optically reflective surface formed on the opposite side of the elastic diaphragm from the magnet, and its surface is mirror-finished. 9 is a bundle type optical fiber. Reference numeral 91 designates an end face of the light emitting fiber, and 92 represents an end face of the light receiving fiber. These end faces are fixed at appropriate positions for projecting light onto the reflecting surface and receiving the reflected light. 10 is a light source, and 11 is a photoelectric element.

In the above description, as shown in FIG. 3, the elastic diaphragm 4 may be made of a magnetic material and the magnet 7 may be fixed to the slit disk 3 so that both may be magnetically attracted. Further, the bundle type optical fiber 9 may be a single bundle in which the light emitting and light receiving fibers 91 and 92 are arranged randomly.

The operation when the device of the present invention having such a configuration is applied to a positive displacement flowmeter will be described with reference to the drawings.

When the rotor of the flowmeter attached to the pipe through which the fluid to be measured rotates, the rotation is transmitted to the output shaft 1. Since the output shaft 1 is provided with a magnetic slit disk 3, as the rotor rotates, the presence or absence of notches or through holes, that is, the presence or absence of magnetic material, is repeated. The position of the reflective surface formed on the elastic diaphragm changes in response to repeated magnetic attraction between the magnetic body and the magnet. Therefore, incidence and reflection of light are repeated in proportion to the flow rate, and this change is detected as a light pulse by a photoelectric element.

As mentioned above, since electricity is not used to detect rotation, it is easier than conventional explosion-proof detectors to take measurements in places where there is a risk of explosion due to electrical discharge, such as flammable gas, oil plants, or coal mines. And the flow rate can be detected safely.

[Brief explanation of the drawing]

FIG. 1 is an embodiment showing the main structure of the present invention, FIG. 2 is a sectional view taken along the line AA of the slit disk of FIG. 1, and FIG. 3 is another embodiment of the present invention. 3... Slit disk, 4... Elastic diaphragm, 7...
Magnet, 9... bundle type optical fiber.

Claims (1)

[Claims for Utility Model Registration] (1) The periphery of an elastic diaphragm is sandwiched between housings, a magnet is fixed to one side of the elastic diaphragm, and a reflective surface with a mirror finish is formed on the other side of the elastic diaphragm. , magnetic slit disks that are rotatably supported in a position that is magnetically attracted by the magnet are arranged opposite each other, and a bundle type optical fiber that projects a light source onto the reflective surface and receives the reflected light is provided. An optical pulse detector, characterized in that a change in the position of a mirror surface on an elastic diaphragm due to magnetic attraction caused by rotation of the magnetic slit disk is detected as an optical pulse by the bundle type optical fiber. (2) The optical pulse detector according to claim (1) of the utility model registration, characterized in that the elastic diaphragm is made of a magnetic material and a magnet is fixed to the slit disk.