JPH0139050B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flangeless electromagnetic flowmeter transmitter, which has been improved to prevent measurement fluid from entering the transmitter.

A flangeless electromagnetic flowmeter transmitter is provided between two connecting pipes by having a plurality of bolts that connect the two connecting pipes passing through the flangeless electromagnetic flowmeter transmitter itself. That is, the first
To explain the bonding procedure in detail with reference to the figure, first, the flangeless electromagnetic flowmeter transmitter 1 is positioned between the flange 2a of the connecting pipe 2 and the flange 3a of the connecting pipe 3, and then the flangeless electromagnetic flowmeter Holes 2a and 3a and mounting pipes (not shown) provided on the flangeless electromagnetic flowmeter transmitter 1 to correspond to the holes, respectively.
A bolt 4 is inserted through the bolt 4, and the flanges 2a, 3a are tightened by the bolt 4. As a result, the flangeless electromagnetic flowmeter transmitter 1 is provided between the connecting pipe 2 and the connecting pipe 3.

Here, the structure of a flangeless electromagnetic flowmeter transmitter according to the prior art will be explained based on FIGS. 2 and 3. Note that FIG. 2 is a partially cutaway perspective view, and FIG. 3 is a cross-sectional view thereof. As shown in both figures, a small-diameter front end flange 5a and four large-diameter holes (not shown) are bored at equal intervals along the circumferential direction at both ends of the plastic measuring pipe 5 through which the measuring fluid flows. A rear end flange 5b is provided. Furthermore, a pair of detection electrodes 6 are disposed on the measurement pipe 5 so as to face each other.
A cylindrical body 7 made of ferromagnetic metal has the same length as the measurement pipe 5 and surrounds it, and furthermore, the inner peripheral surface of the rear end of the cylinder 7 and the outer peripheral surface of the rear end flange 5b are fixed. has been done. Further, a pair of magnetic field generating coils 8 (only one is shown) are disposed on the inner circumferential surface of the cylindrical body 7 so as to face each other. Therefore, the cylindrical body 7 also acts as a magnetic path for the magnetic flux generated by the magnetic field generating coil 8. The four mounting pipes 9 (only three are shown) made of fluororesin and having the same length as the measuring pipe 5 have internal spaces formed by holes formed in the rear end flange 5b, respectively. It is fixed perpendicularly to the inner surface of the rear end flange 5b so as to communicate with the rear end flange 5b. The inner surface of the front end flange 5a, the outer periphery of the measuring pipe 5, and the rear end flange 5
The space formed by the inner surface of b and the inner peripheral surface of the cylinder 7 is filled with a thermosetting filler 10 such as epoxy resin, and this filler 10 connects the detection electrode 6 and the magnetic field generation coil. 8. The mounting tube 9 is fixed and held in a predetermined position. Although not shown in the drawings, the space filled with the filler 10 is also provided with lead wires and various electronic circuits that connect the detection electrode 6 to instruments outside the flangeless electromagnetic flowmeter transmitter. There is.

However, in order to manufacture this according to the conventional technology, the measurement pipe 5, the front end flange 5a, the rear end flange 5b, the detection electrode 6, the cylinder body 7, the magnetic field generation coil 8, the mounting tube 9, etc. are assembled. Although filling work with the filler 10 will be performed later, it is necessary to prevent the filler 10 from entering the attachment tube 9 during this filling work. Therefore, a jig for closing the attachment tube 9 is required during the filling operation, making the filling operation complicated. Further, when used for a long period of time, external force or the like acts on various parts fixed and held by the filler 10, and there is a possibility that gaps may occur between the various parts and the filler 10. In particular, a gap is likely to occur between the attachment tube 9 and the filler 10. This is because, as described above, the bolts that connect the flangeless electromagnetic flowmeter transmitter and the connecting pipe pass through the mounting pipe 9, and therefore a large force is applied to the mounting pipe 9. If such a gap occurs, the measurement fluid, water, etc. may enter the inside through this gap, and there is a risk that failure or malfunction may occur due to the intrusion of the measurement fluid, etc. Furthermore, if the fluid to be measured is explosive, there is a risk that it may come into contact with internal electronic circuits and cause an explosion. Furthermore, when this flangeless electromagnetic flow transmitter is provided between two connecting pipes, it receives compressive force from both connecting pipes, but this compressive force is mostly supported by the cylinder 7. This is because the cylinder 7 is made of a ferromagnetic metal with high mechanical strength, whereas the measuring pipe 5, the mounting pipe 9, the filler 10, etc. are made of plastic and fluorine resin, respectively, with low mechanical strength. This is because it is made of epoxy resin. As a result, if a large compressive force is applied due to an unexpected accident, it cannot withstand this force.

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, an object of the present invention is to provide a flangeless electromagnetic flowmeter transmitter that is robust and has fewer failures. The structure of the present invention that achieves this object is to connect the outer peripheries of two ring-shaped housing end plates to both ends of a cylindrical ferromagnetic metal housing body, and to connect opposing holes to the housing body. A plurality of pairs of holes are formed in the end plate, and both ends of insulating and non-magnetic measuring pipes are respectively joined to the inner periphery of the housing end plate, and bolts are respectively attached to the periphery of the paired holes. It is characterized in that both ends of the penetrating mounting tube are joined.

Embodiments of the present invention will be described in detail below based on the drawings.

FIG. 4 is a partially cutaway perspective view of an embodiment of the present invention, FIG. 5 is a longitudinal sectional view of the embodiment, and FIG. 6 is a sectional view taken along the line A--A in FIG. 5. As shown in these figures, the outer peripheries of ring-shaped iron housing end plates 12a and 12b are welded to both ends of a cylindrical iron housing body 11. The housing end plate 12a has four holes formed at equal intervals along the circumferential direction, and the housing end plate 12b also has holes opposite to the holes. The inner peripheral surface of the pipe 13 made of non-magnetic stainless steel is lined with an insulating material 14, and both form a measuring pipe 15 that is insulated from the measuring fluid and unaffected by magnetic fields. Both ends of this measuring pipe 15 are welded to the inner peripheries of the housing end plates 12a and 12b, respectively. The four mounting tubes 16 are welded at both ends to the housing end plates 12a, 12b located on the periphery of the holes, respectively, so as to communicate the opposing holes formed in the housing end plates 12a, 12b. . A bolt 17 is inserted into the mounting tube 16, as particularly shown in FIG. This bolt 17 connects the flange 18a of the connecting pipe 18 that contacts the housing end plate 12a and the flange 19a of the connecting pipe 19 that contacts the housing end plate 12b.
The tightening force from a, 19a is mainly supported by the attachment pipe 16. In this way, a sealed space surrounded by the inner circumferential surface of the housing body 11, the inner circumferential surfaces of the housing end plates 12a and 12b, the outer circumferential surface of the measuring pipe 15, and the outer circumferential surface of the attachment tube 16 is formed. In this sealed space, the measuring pipe 15
a detection electrode 20 inserted into the housing body 11, an electrode cover 21 covering the detection electrode 20, a magnetic field generating coil 22 consisting of an iron core 22a and a coil 22b integrally protruding from the inner peripheral surface of the housing body 11, and the necessary electronics. A circuit (not shown) is provided. Note that a hole 23 formed in the housing body 11 is for passing a lead wire (not shown) connected to an electrode, and this hole 23 is provided with a gasket (not shown).

By the way, one method of manufacturing such a flangeless electromagnetic flowmeter transmitter is to use a cylindrical housing body 11 and ring-shaped housing end plates 12a, 1.
There is a method of preparing 2b etc. and assembling them according to the required steps. In addition, as another method, the seventh
As shown in the figure, the housing body 1 shown in FIG.
1 and the housing end plates 12a and 12b are assembled into two halves on a plane including the axis, and this member is formed by casting.
There is also a method of manufacturing by welding.

In this embodiment, the detection electrode 20, the magnetic field generation coil 22, the electronic circuit, etc. are provided in a sealed space formed by the housing body 11, the housing end plates 12a, 12b, the measuring pipe 15, and the mounting pipe 16. Therefore, the measurement fluid etc. will not enter the sealed space. Therefore, no failures or errors occur due to the measured fluid. Furthermore, the members forming the sealed space are welded together to form a casing, and the casing as a whole has a structure that can withstand external forces, thereby improving mechanical strength. Furthermore, since each part forming the housing is made of iron, which has high mechanical strength, it has extremely high mechanical strength, in addition to the advantages of the above-mentioned structure. Note that when filling the sealed space with a filler material in order to further improve the strength, it is sufficient to fill the filler material through the hole 23, so that the inner space of the mounting tube 16 is There is no filler material inside. Therefore, there is no need to close the attachment tube 16, and this filling operation is easy.

8 and 9 show a second embodiment of the invention. As shown in both figures, one end of the electrode isolation pipe 24 is welded to the outer peripheral surface of the measurement pipe 15 so as to surround the detection electrode 20, and the other end is welded to the periphery of a hole drilled in the housing body 11. is welded to. In this embodiment, the housing main body 11 and the housing end plates 12a, 12b are made by casting, and a hemispherical member is cast and both members are connected by bolts. In this embodiment, since the coil 22b through which a large current flows and the detection electrode 20 are isolated, the detection electrode 20
The voltage generated at zero can be extracted accurately without being affected by the magnetic field by the coil 22b.

As specifically explained above with the examples,
According to the present invention, various parts and electronic circuits provided for detecting the measured fluid are connected to the housing body,
Because it is surrounded watertight by the housing end plate, measuring pipe, and mounting pipe, the measuring fluid cannot enter the interior, and no malfunctions or accidents will occur due to the measuring fluid. Furthermore, since the housing main body, housing end plate, measuring pipe, and attachment pipe are joined to each other so that they can withstand the compressive force applied from the connecting pipe as a whole, mechanical strength is also improved.

[Brief explanation of drawings]

Fig. 1 is a front view showing a flangeless electromagnetic flowmeter transmitter attached to a connecting pipe, Fig. 2 is a partially cutaway perspective view of a flangeless electromagnetic flowmeter transmitter according to the prior art, and Fig. 3 The figure is this cross-sectional view,
FIG. 4 is a partially cutaway perspective view of the first embodiment of the present invention, FIG. 5 is a vertical cross-sectional view of the same, and FIG. FIG. 7 is a perspective view for explaining one method of manufacturing this embodiment, FIG. 8 is a vertical sectional view showing a second embodiment of the invention, and FIG. 9 is a perspective view thereof. In the drawing, 4 and 17 are bolts, 11 is the housing body, 12a and 12b are housing end plates, and 5 and 1
5 is a measuring pipe, and 16 is a mounting pipe.

Claims (1)

[Claims] 1. The outer peripheries of two ring-shaped housing end plates are respectively joined to both ends of a cylindrical ferromagnetic metal housing body, and a plurality of opposing holes are bored in the housing end plates, and Both ends of insulating and non-magnetic measuring pipes are respectively joined to the inner periphery of the housing end plate, and both ends of mounting pipes through which bolts pass are respectively joined to the periphery of the pair of holes. A flangeless electromagnetic flowmeter transmitter characterized by: