JPH0228406Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to an electromagnetic flow meter detector, and particularly to a magnetic pole plate of a magnetic field generating device thereof.

[Technical background of the invention and its problems]

As shown in FIGS. 1 and 2, the magnetic field generating device of the electromagnetic flowmeter detector is composed of a core 4, a magnetic pole plate 5, and a coil 6. A hole 7 for taking out a signal line and a screw hole 8 for fixing the magnetic field generator to the outer casing 2 via the plate 3 are provided in the center of the core 4 . Because the magnetic field generator is attached to the outer casing 2 via the plate 3, it requires screw holes, and because the magnetic field generator has a cantilevered structure, it requires a certain degree of strength. , the core 4 and the magnetic pole plate 5 are made of an integral magnetic material such as steel, pure iron, cast iron, or the like. Therefore, the magnetic flux generated by the magnetic field generator passes through the magnetic pole plate 5, causing a large eddy current to flow, resulting in a large eddy current loss. On the other hand, the eddy current generated here also becomes a noise source for the output signal of the electrode 9 provided in the measuring tube 1, and there is a problem in that it adversely affects the characteristics of the electromagnetic flowmeter.

[Purpose of invention]

This invention reduces eddy current loss in the magnetic pole plate,
It is an object of the present invention to provide an electromagnetic flowmeter detector with good characteristics and less noise generated in the output.

[Summary of the idea]

In this invention, the magnetic pole plate of the magnetic field generator is constructed with a composite structure of a laminate of silicon steel plates and reinforcing materials made of other materials, and the magnetic pole plate of the magnetic field generating device is constructed with a composite structure, which suppresses eddy currents while maintaining the same strength as an integral magnetic pole plate. The desired purpose was achieved by decreasing the amount of water.

[Example of idea]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 shows an embodiment of the core and magnetic pole plate of the electromagnetic flowmeter detector according to the present invention. The core 4 has a structure in which a required amount of silicon steel plates 4b are wound around a reinforcing member 4a, and a hole 7 and a screw hole 8 for taking out a signal line are provided in the reinforcing member 4a. The reinforcing material 4a may be made of a metal with relatively high electrical resistance, such as steel, stainless steel, or cast iron (including ductile cast iron). (to reduce the size), insulating plastics such as FRP may be used. Similarly to the above, the magnetic pole plate 5 is also made of metal or plastic reinforcing material 5a.
It has a composite structure with a laminate 5b in which magnetic poles of silicon steel plates are laminated. In the core and magnetic pole plate configured as described above, the eddy current loss is reduced due to the laminated structure of silicon steel plates, and the reinforcing material ensures strength and allows conventional mounting.

Next, some other embodiments of the present invention will be described.

In the embodiment shown in FIG. 4, the core 4 has a structure in which silicon steel plates 4b are stacked on both sides of a reinforcing member 4a, and the reinforcing member 5a of the magnetic pole plate 5 is placed relatively near the center of the laminate 5b of silicon steel plates. It is a structure provided in a part.

The embodiment shown in FIG.
It has a structure in which the silicon steel plate 5b of the magnetic pole plate 5 and the silicon steel plate 5b of the magnetic pole plate 5 are integrated and laminated.

The embodiment shown in FIG. 6 differs from the ones in FIGS. 3 to 5 in that the lamination direction is different, and Y-shaped silicon steel plates are laminated in the axial direction of the measuring tube with reinforcing members of the same shape in between. The core 4 and the magnetic pole plate 5 are integrally formed.

In the embodiment shown in FIG. 7, after assembling a core 4 made of a reinforcing material 4a and a silicon steel plate 4b laminated with the reinforcing material sandwiched therebetween, and a magnetic pole plate 5 made of a laminate 5b of silicon steel plates, the surface is coated with plastic (for example, It has a structure in which it is coated and fixed with glass base material reinforced epoxy resin) 10.

In the embodiment shown in FIG. 8, the core 4 has a structure in which a required amount of silicon steel plates 4b are wound around a reinforcing member 4a in the shape of a round bar, and the magnetic pole plate 5 is attached to a measuring tube made of a laminated body 5b of silicon steel plates. Copper on the opposite side of the opposing arcuate surface,
It has a composite structure in which reinforcing materials 5a made of a good electrical conductor such as aluminum are layered. As an electromagnetic flowmeter, magnetic flux is required on the center side of the arc of the magnetic pole plate 5 facing the measuring tube, and the opposite side is unnecessary and it is better not to generate magnetic flux. By arranging the reinforcing material 5a made of a good electrical conductor on the side of the magnetic pole plate where magnetic flux is unnecessary, a large amount of eddy current is generated in the reinforcing material 5a, and the magnetic resistance on this side increases, so that the reinforcing material 5a is placed on the side where magnetic flux is unnecessary. A large amount of magnetic flux can be generated.

[Effect of idea]

As described in detail above, according to the present invention, the core and magnetic pole plates of the magnetic field generator are configured with a composite structure of a laminate of silicon steel plates and reinforcing materials made of other materials. It has the necessary strength for a structure that is attached to the outer casing due to its cantilevered structure, and reduces eddy current loss. Therefore, it has sufficient strength to withstand vibrations, and also has sufficient strength to withstand losses caused by eddy currents and electrodes. It is possible to provide a lightweight type electromagnetic flowmeter detector with good characteristics and less noise generated in response to output signals from the sensor.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional schematic diagram showing the configuration of an electromagnetic flowmeter detector, Fig. 2 is a perspective view showing a conventional core and magnetic pole plate, and Figs. FIG. 6 is a perspective view showing different embodiments of the core and the magnetic pole plate. 1...Measuring tube, 2...Outer casing, 3...Plate,
4... Core, 4a... Core reinforcing material, 4b... Silicon steel plate, 5... Magnetic pole plate, 5a... Magnetic pole plate reinforcing material, 5b... Silicon steel plate laminate, 6... Coil, 7...Hole for signal line extraction, 8...Screw hole,
9... Electrode, 10... Plastic molding material.

Claims (1)

[Claims for Utility Model Registration] (1) A measuring tube made of a non-magnetic material through which a fluid to be measured flows;
at least one pair of magnetic field generators disposed outside the measuring tube to generate a magnetic field perpendicular to the axis of the measuring tube; In the electromagnetic flowmeter detector, the electromagnetic flowmeter detector is provided with a pair of electrodes disposed at the same time, and a magnetic pole plate facing the measuring tube is attached to the tip of the core of the magnetic field generating device, the magnetic pole plate being made of a silicon steel plate. An electromagnetic flowmeter detector characterized by having a composite structure of a laminate and a reinforcing material made of other materials. (2) The electromagnetic flowmeter detector according to claim 1, wherein the reinforcing material is made of a metal material with relatively high electrical resistance. (3) The electromagnetic flowmeter detector according to claim 1, wherein the reinforcing material is made of a good conductor. (4) The electromagnetic flowmeter detector according to claim 1, wherein the reinforcing material is made of an insulating material.