JPH044975Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electromagnetic flowmeter that electrically measures the flow rate of a fluid to be measured flowing within a measurement pipe.

[Prior Art] Conventionally, the inner wall of a measurement tube of this type of electromagnetic flowmeter is usually coated with a lining material, and the material is changed depending on the fluid to be measured flowing through the measurement tube.

However, changing the lining material each time the fluid to be measured is changed is not only complicated, but also requires time and troubles due to the need to request the manufacturer.

For this reason, in recent years, electromagnetic flowmeters having a double tube structure consisting of an outer tube and an inner tube have been proposed. In other words, on the user side,
This is because by preparing a large number of inner tubes lined with lining materials corresponding to the fluid to be measured and replacing these inner tubes as necessary, it is possible to quickly respond to changes in the fluid to be measured.

By the way, this type of electromagnetic flowmeter has conventionally been provided with a ground ring connected to the inner tube in order to maintain the fluid to be measured flowing through the inner tube and the entire flowmeter at the same potential.

As a method of connecting this ground lead wire, a method of directly connecting the converter and the inner tube has been considered.

[Problem that the invention attempts to solve]

However, the conventional electromagnetic flowmeter has a structure in which the ground lead wire is inserted through a hole for introducing the lead wire provided in the outer tube, which causes the problem of complicating the connection work.

Additionally, a connector for connecting the ground lead wire is required, which increases the number of parts.

[Means for solving problems]

The electromagnetic flowmeter according to the present invention includes a threaded rod for preventing the connector from coming out, which is inserted into the through hole of the connector plug from the upper opening end and screwed onto the measuring tube side. A ground lead wire is connected.

[Effect]

In this invention, the ground lead wire is connected to the opposite end of the threaded part of the threaded rod for preventing connector removal, so the ground lead wire can be connected outside the case. connector is no longer required.

〔Example〕

FIG. 1 is a sectional view showing an electromagnetic flowmeter according to the present invention. In the figure, the reference numeral 1 is a cylindrical case, and a mounting part 3 for fixing the transmitter case 2 or the terminal box is integrally protruded from the central part in the axial direction. A hole 4 for introducing a lead wire is provided in the center. Reference numeral 5 denotes a measuring tube having flanges (not shown) at both ends, which is inserted from the axial direction and fitted into the case 1, and whose inner peripheral surface is covered with an insulating lining 6. There is. A pair of excitation coils 7, 7 that form a magnetic field in a direction perpendicular to the flow direction of the fluid to be measured and a receptacle 9 having a through hole 8 in the center are disposed between both flanges of the measuring tube 5. Also,
A pair of electrodes 10, 10 (only one shown) is arranged on the wall of the measuring tube 5 so as to face each other in a direction perpendicular to the flow direction of the fluid to be measured and via the magnetic field formed by the excitation coils 7, 7. installed on. The receptacle 9 is provided with four male contacts 9a to 9d (9a and 9c are not shown), of which, for example, the male contacts 9a and 9c are connected to the excitation coils 7, 7
Furthermore, male contacts 9b and 9d are connected to the electrodes 10, 10, respectively, by lead wires 11 (the lead wires on the excitation coils 7, 7 side are not shown). Reference numeral 12 denotes a mounting base for fixing the receptacle 9, which is placed and fixed on the outer peripheral surface of the measurement tube 5, and a screw hole 13 communicating with the through hole 8 is provided on the receptacle side. There is. Reference numeral 14 denotes a connector plug having a through hole 15 opening toward the through hole 8 side of the receptacle 9, and is attached to the receptacle 9 so that its upper end faces into the lead wire introduction hole 4. This connector plug 14 has each of the male contacts 9a to 9a.
Female contacts 14a to 14d connected to 9d
(14a and 14c are not shown) are provided. One end of each lead wire 16a to 16d (16a and 16c not shown) is connected to the upper end of these female contacts 14a to 14d.
The other end is an electric circuit (or a terminal of a terminal box) of a converter (not shown) disposed inside the transmitter case 2.
It is connected to the. Reference numeral 17 denotes a mounting pipe communicating with the through hole 15, the lower end of which is connected to the connector plug 14.
The upper end is exposed inside the transmitter case 2. Reference numeral 18 denotes a threaded rod for preventing the connector from coming out, which is inserted into the mounting tube 17 and inserted from the upper open end of the through hole 15 of the connector plug 14, passes through the through hole 8 of the receptacle 9, and is inserted into the screw hole 13. A ground lead wire 19 connected to a ground terminal (not shown) is connected to the opposite end of the screw portion. Note that 20 is a bolt for fixing the measuring tube 5 inside the case 1.

Therefore, when connecting the connector plug 14 and the receptacle 9, the connector plug 14
into the receptacle 9, and screw the threaded rod 18 into the threaded hole 13. At this time, the head of the threaded rod 18 presses the upper open end of the attachment tube 17, and the connector plug 14 descends together with the attachment tube 17. and,
The connector plug 14 is firmly positioned and fixed to the receptacle 9, and the male contacts 9a to 9d of the receptacle 9 and the female contacts 14a to 14d of the connector plug 14 are connected.

In the electromagnetic flowmeter configured in this way,
Since the structure is such that the ground lead wire 19 is connected to the opposite end of the threaded part of the threaded rod 18 for preventing connector removal,
The ground lead wire 19 can be connected to the threaded rod 18 outside the case 1, and a connector for the ground lead wire is not required.

Although this embodiment shows an example in which the threaded rod 18 is screwed into the screw hole 13 of the mounting base 12, the present invention is not limited to this, and as shown in FIG. A conductor 22 having a screw hole 21 is provided in the through hole 8 of the conductor 22.
Even if the threaded rod 18 is screwed into the threaded hole 21, the same effect as in the embodiment can be obtained. In this case, the screw 23 is inserted through the mounting base 12 and is screwed into the screw hole 21 on the side opposite to the threaded rod.

Further, as shown in FIG. 3, a conductor 26 having a screw hole 24 and a bottomed hole 25 at both ends is provided in the through hole 8, and a threaded rod 18 is screwed into the screw hole 24 of the conductor 26. A spring 27 may be loaded between the bottom hole 25 and the mounting base 12.

Furthermore, as shown in FIG. 4, an elastic body such as a disc spring 28 may be used instead of the spring 27. In this case, the disc spring 28 is attached to the mount side of the conductor 29, but it is desirable to prevent the disc spring 28 from coming off, for example, by caulking the end of the conductor 29.

[Effect of idea]

As explained above, according to the present invention, a threaded rod for preventing the connector from coming out is inserted into the through hole of the connector plug from the upper open end and screwed onto the measuring tube side, and the opposite threaded portion of the threaded rod is provided. Since the ground lead wire is connected to the end, the ground lead wire can be connected outside the case, making the connection work extremely simple. In addition, the connector for connecting the ground lead wire, which was conventionally required, is no longer necessary, the number of parts can be reduced, and costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an electromagnetic flowmeter according to the present invention, and FIGS. 2, 3, and 4 are sectional views showing other embodiments. 1... Case, 4... Hole for lead wire introduction, 5
...Measurement tube, 8...Through hole, 9...Receptacle, 14...Connector plug, 15...Through hole,
18...Threaded rod for preventing connector removal, 19...Earth lead wire.

Claims (1)

[Scope of utility model registration request] A cylindrical case that has a hole for introducing a lead wire in the center in the axial direction, a measurement tube that fits inside this case and has flanges at both ends, and a cylindrical case that is arranged between the flanges of this measurement tube and located in the center. a receptacle having a through hole;
A connector plug is attached to the receptacle so that its upper end faces the hole for introducing the lead wire, and has a through hole that opens toward the through hole. An electromagnetic flowmeter characterized by comprising a threaded rod screwed onto the measuring tube side to prevent connector removal, and a ground lead wire is connected to the opposite end of the threaded rod.