JP2019191084A - Electromagnetic flowmeter and inside shield member thereof - Google Patents

Abstract

To improve the accommodability of an electrode cable led out from an electrode substrate.SOLUTION: The present invention comprises: a measuring tube having a passage which a measurement fluid passes through; an electrode for extracting an electromotive force generated inside of the passage; an electrode substrate for outputting a signal based on the electromotive force extracted by the electrode; an electrode cable for conveying the signal outputted from the electrode substrate; and an inside shield member covering the measuring tube. Inside a space covered with the inside shield member are arranged the electrode, the electrode substrate and the electrode cable, and the inside shield member has a slit part for leading out the electrode cable.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an electromagnetic flow meter capable of measuring a flow rate of a fluid to be measured flowing in a flow path.

  Conventionally, electromagnetic flowmeters have been widely used in places such as factories where fluid management is necessary (see, for example, Patent Document 1). In the electromagnetic flow meter as described in Patent Document 1, a pair of electrodes for extracting an electromotive force generated in the fluid to be measured in the flow path by forming a magnetic field in the flow path through which the fluid to be measured flows by the excitation coil, A pair of electrode substrates connected to the pair of electrodes are accommodated inside a structure such as a shield disposed around the measurement tube. An electrode cable for taking out a signal output from the electrode substrate is connected to each of the pair of electrode substrates.

Japanese Patent No. 4721073

  In the configuration described in Patent Document 1, an electrode cable for taking out a signal output from the electrode substrate is drawn out from the shield through a take-out hole provided in the shield. However, as the electromagnetic flowmeter is miniaturized, the space for drawing out the electrode cable from the shield and the space for routing the electrode cable become smaller. For this reason, there is a problem that the workability of the electrode cable routing operation is poor. In addition, if the positional relationship between the electrode cable and the surrounding structure is not taken into account, the electrode cable is bitten by a shield or the like disposed on the outside thereof, and thus there is a problem that the electrode cable is damaged. It was.

  An electromagnetic flowmeter according to one aspect of the present invention is based on a measurement tube having a flow path through which a fluid to be measured flows, an electrode for extracting an electromotive force generated in the flow path, and the electromotive force extracted by the electrode. An electrode substrate that outputs a signal, an electrode cable that transmits the signal output from the electrode substrate, and an inner shield member that covers the measurement tube, and inside the space covered by the inner shield member, The electrode, the electrode substrate, and the electrode cable are disposed, and the inner shield member has a slit portion for drawing out the electrode cable on an upper surface.

  According to another aspect of the electromagnetic flowmeter of the present invention, the inner shield member includes a first inner shield member having a first sub-slit and a second inner shield member having a second sub-slit, The slit portion is configured by combining the first sub-slit and the second sub-slit.

  According to the electromagnetic flowmeter of another aspect of the present invention, the first inner shield member and the second inner shield member are formed in a U-shape on the upper surface, so that the first sub slit and the second A sub-slit is formed.

  According to another aspect of the electromagnetic flowmeter of the present invention, the electromagnetic flowmeter further includes an intermediate shield member configured to cover the inner shield member, and the intermediate shield member is bent in parallel with the upper surface of the inner shield member. It has a bent part.

  According to the electromagnetic flow meter according to another aspect of the present invention, the bent portion has an end portion of the bent portion that overlaps the slit portion and the flow path direction of the flow channel, rather than an end portion of the slit portion. The slit portion is configured not to protrude toward the center side.

  According to the electromagnetic flow meter according to another aspect of the present invention, the bent portion has a central portion of the slit portion so as to cover either the upstream side or the downstream side surface of the slit portion on the upper surface of the inner shield member. It has the control part which protruded in the side, It is characterized by the above-mentioned.

  According to the electromagnetic flow meter of another aspect of the present invention, the electromagnetic flow meter further includes a case body that accommodates at least the measurement tube and the inner shield member therein, and the slit portion of the inner shield member is provided inside the case body. There is provided a claw member for hooking the electrode cable drawn out from the cable.

  According to an electromagnetic flow meter according to another aspect of the present invention, the inner shield member is formed of a nonmagnetic material.

  According to the electromagnetic flow meter according to another aspect of the present invention, the end face of the substrate to which the electrode cable is connected is located on the inner side than both ends of the slit part.

  According to the electromagnetic flow meter according to another aspect of the present invention, the electrode is a convex portion in which a part of the electrode protrudes toward the electrode substrate side, and the electrode and the electrode substrate are electrically connected. A convex portion connected to the electrode substrate, wherein the convex portion wraps around the outside of the electrode substrate and is fixed to the electrode substrate.

  An inner shield member according to an aspect of the present invention is an inner shield member provided around a measurement tube of an electromagnetic flow meter, and has a slit portion on an upper surface.

  According to an inner shield member according to another aspect of the present invention, the inner shield member includes a first inner shield member having a first sub-slit and a second inner shield member having a second sub-slit, The slit portion is configured by combining the first sub-slit and the second sub-slit.

  According to an inner shield member according to another aspect of the present invention, the first inner shield member and the second inner shield member have upper surfaces formed in a U-shape.

  According to the electromagnetic flow meter according to one aspect of the present invention, workability when drawing the electrode cable from the electrode substrate to the outside of the shield member can be improved, and interference with surrounding structures can be made when the electrode cable is routed. It becomes possible to make it difficult.

1 is an external perspective view of an electromagnetic flow meter according to an embodiment of the present invention. It is a disassembled perspective view of the electromagnetic flowmeter which concerns on one Embodiment of this invention. It is sectional drawing of the electromagnetic flowmeter which concerns on one Embodiment of this invention. It is a top view of the shield member of the electromagnetic flowmeter concerning one embodiment of the present invention. It is other sectional drawing of the electromagnetic flowmeter which concerns on one Embodiment of this invention. It is a block diagram of the electromagnetic flowmeter concerning one embodiment of the present invention. It is a top view of the shield member of the electromagnetic flowmeter concerning other embodiments of the present invention. It is a figure for demonstrating the electromagnetic flowmeter which concerns on other embodiment of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of an electromagnetic flow meter according to the first embodiment of the present invention. In FIG. 1, a case body 10, an outer shield member 11 covering the case body 10, a measuring tube 12 provided so as to penetrate the inside of the case body 10, and a case to be measured are provided above the case body 10. A display unit 20 for displaying a flow rate of fluid, a measurement condition for measuring a flow rate, and the like, and an operation unit 30 provided above the case body 10 for setting display contents of the display unit 20 and measurement conditions for measuring the flow rate; An electromagnetic flow meter with is shown. In the following drawings, the flow path direction of the measuring tube 12 is the x axis, the direction perpendicular to the x axis and the side surface of the outer shield member 11 is provided, the y axis, the direction perpendicular to the x axis and the y axis. The z axis is assumed.

  The measuring tube 12 has a flow path through which the fluid to be measured flows. As shown in FIG. 1, a metal outer shield member 11 is provided so as to cover a side surface and a bottom surface of the case body 10 at a portion where the measurement tube 12 is disposed in the case body 10. The outer shield member 11 blocks radiation noise that enters the measurement tube 12 from the outside.

  FIG. 2 is an exploded perspective view of the electromagnetic flow meter according to the present embodiment. As shown in FIG. 2, the case body 10 has a substantially rectangular parallelepiped shape, and a base 13 a and a base 13 b are connected to an upstream end and a downstream end of the measuring tube 12 via sealing members 14 a and 14 b. Each has an opening for fixing.

  FIG. 3 shows a cross-sectional view in a cross section orthogonal to the flow path direction of the electromagnetic flowmeter in the present embodiment. As shown in FIGS. 2 and 3, the case body 10 includes a control unit unit 50 including a display unit 20, an operation unit 30, a display control board 40, a control board 41, and an excitation board 42. It has an opening for disposing upward through the sealing member 14c. As shown in FIG. 3, the measurement tube 12, an inner shield member 101 and an intermediate shield member 112 described later are accommodated in the case body 10.

  The display control board 40 can control the display unit 20 and the LEDs arranged as the backlight of the display unit 20 in accordance with a control signal from the control board 41.

  The excitation board 42 includes connectors 43 and 44 that are connected to electrode cables 115a and 115b that transmit signal outputs of the electrode boards 103a and 103b. FIG. 3 shows a state in which the electrode cables 115a and 115b are pulled out and connected to the connectors 43 and 44 located at the upper part. However, the two drawn electrode cables 115a and 115b are twisted a plurality of times. It is preferable to connect to the excitation substrate 42 later. By twisting the two electrode cables 115a and 115b, in-phase noise can be removed. The excitation substrate 42 receives the signal output of the electrode substrates 103a and 103b output via the electrode cables 115a and 115b, and outputs the signal output to the control substrate 41. The excitation board 42 has a connector 45 for connecting a cable to the excitation coil 109, and the excitation current for the excitation coil 109 can be controlled by a control signal from the control board 41.

  The control board 41 generates signals generated in the measurement tube 12 based on the relationship between the magnetic field generated in the measurement tube 12 from the excitation coil 109 by the signal input from the excitation substrate 42 and the flow rate of the fluid to be measured flowing through the measurement tube 12. By acquiring electric power through the electrodes 102a and 102b, the flow rate of the fluid to be measured flowing through the measurement tube 12 is measured. The control board 41 can control input / output with respect to the display control board 40 and the excitation board 42 in accordance with an input to the operation unit 30 or a flow rate measurement. Further, an external interface (not shown) can be connected to the control board 41, and measurement data such as a detected flow rate can be transmitted or input from an external device can be received.

  A base 13a and a base 13b are inserted into and fitted into the upstream and downstream ends of the measuring tube 12 via sealing members 14d and 14e (also shown in FIG. 5) such as O-rings. ing.

  The inner shield member 101 is provided so as to cover the periphery of the central portion of the measurement tube 12. The inner shield member 101 can be formed of, for example, a nonmagnetic material. As shown in FIG. 3, the inner shield member 101 includes a first inner shield member 101a and a second inner shield member 101b. Inside the space covered by the first inner shield member 101a and the second inner shield member 101b of the inner shield member 101, a pair of electrodes 102a and 102b arranged opposite to each other with the measuring tube 12 as a center, and a pair of electrodes 102a And electrode substrates 103a and 103b provided on the outer peripheral side of 102b and substrate holders 104a and 104b for holding the electrode substrates 103a and 103b, respectively, are arranged.

  The electrodes 102a and 102b are formed with convex portions 105a and 105b in which, for example, a part of a copper foil constituting the electrode is projected toward the electrode substrates 103a and 103b, and the electrode substrate 103a is formed by the convex portions 105a and 105b. And 103b, respectively. The electrode substrates 103a and 103b are connected to connectors 43 and 44 of the excitation substrate 42 via electrode cables 115a and 115b. Note that the protrusions 105a and 105b do not necessarily have to be formed integrally with the electrodes 102a and 102b as in this embodiment, and the electrodes 102a and 102b and the electrode substrate are formed by metal members such as lead wires formed separately. 103a and 103b may be connected.

  As shown in FIG. 3, the convex portions 105a and 105b wrap around the outside of the electrode substrates 103a and 103b (the surface side opposite to the surface to which the electrode cables 115a and 115b are respectively connected), For example, it is fixed to 103b by soldering. Since the electrode substrates 103a and 103b are provided on the inner side with respect to the convex portions 105a and 105b, it is possible to secure an accommodation space for the connection portion including the convex portions 105a and 105b on the outer side.

  The electrodes 102 a and 102 b take out an electromotive force generated in the fluid to be measured flowing through the measurement tube 12. The electrode substrates 103a and 103b output signals based on the electromotive forces extracted by the electrodes 102a and 102b. In the present embodiment, for example, a voltage follower circuit is provided for one or both of the electrode substrates 103a and 103b, the output is taken out by the electrode cables 115a and 115b, and the differential amplifier circuit provided on the excitation substrate 42 is provided. It can be amplified by an amplifier circuit such as Substrate holders 104a and 104b have body portions 106a and 106b formed in an arc shape corresponding to the outer peripheral surface of measuring tube 12, respectively, and holding portions 107a and 107b that can hold electrode substrates 103a and 103b, respectively. .

  An exciting coil 109 wound around the iron core portion 108 is disposed so as to generate a magnetic field in the measuring tube 12 at a position facing the control unit 50 across the measuring tube 12. As shown in FIG. 2, a magnetic field adjusting member 110 and a copper foil seal 111 are fixed to the upper part of the exciting coil 109. The magnetic field adjusting member 110 is formed in a substantially rectangular shape with a high permeability material such that the flow channel direction of the measuring tube 12 becomes the longitudinal direction. A copper foil seal 111 formed in a circular shape, for example, is affixed further above the magnetic field adjustment member 110. The magnetic field adjustment member 110 can be adjusted so that the magnetic field generated by the excitation coil 109 is uniformly generated from the upper surface of the magnetic field adjustment member 110. Thereby, the variation in the detection voltage by the electrodes 102a and 102b can be reduced, and the detection accuracy can be improved.

  An intermediate shield member 112 is provided so as to cover the periphery of the inner shield member 101 and the excitation coil 109. The intermediate shield member 112 is configured by screwing the upper intermediate shield member 112b to a lower intermediate shield member 112a formed in a substantially U shape so as to cover the bottom and sides of the exciting coil 109. . The lower intermediate shield member 112 a has a bent portion 112 c that is bent so that both ends of the lower intermediate shield member 112 extend upward to the upper portion of the inner shield member 101 and become parallel to the upper surface of the inner shield member 101. The upper surface of the bent portion 112c is screw-fixed with the upper intermediate shield member 112b, so that the measuring tube 12, the inner shield member 101, and the excitation coil 109 are placed inside the space covered with the lower intermediate shield member 112a and the upper intermediate shield member 112b. Can be accommodated.

  The intermediate shield member 112 is formed by plating another magnetic body (for example, nickel) on the surface of a ferromagnetic metal such as iron. Thus, a magnetic path for the magnetic field generated in the exciting coil 109 is formed by the magnetic body constituting the intermediate shield member 112 while preventing radiation noise coming from the outside. Further, a high permeability material such as permalloy may be disposed on the surface of the upper intermediate shield member 112b on the measurement tube 12 side. In particular, it is preferably provided in a portion (center portion) overlapping the measurement tube 12 in the y direction, and more preferably provided only in a portion overlapping the measurement tube 12 in the y direction.

FIG. 4 is a top view showing the intermediate shield member 112 with the upper intermediate shield member 112b removed. As shown in FIG. 4, the first inner shield member 101a is attached and fixed to the second inner shield member 101b. The first inner shield member 101a and the second inner shield member 101b each have a first attachment portion 101a ₁ and a second attachment portion 101b ₁ for attaching a first inner shield member 101a to the second inner shield member 101b. The first attachment portion 101a ₁ can be, for example, a protrusion provided at the tip portion of the upper surface of the first inner shield member 101a, and the second attachment portion 101b ₁ is, for example, the upper surface of the second inner shield member 101b. It can be set as the attachment hole provided in the front-end | tip part.

For example, a first inner shield member 101a by fitting the projections of the first attachment portion 101a ₁ into the mounting hole of the second mounting portion 101b ₁ is fixed to the second inner shield member 101b.

In the present embodiment, the first inner shield member 101a and the second inner shield member 101b have the same structure provided symmetrically with respect to the central axis of the measuring tube 12, and are each formed in a substantially U shape in the yz plane. Has been. Thus the first attachment portion 101a ₁ is provided on the upper side of the portion of FIG. 3 in the first inner shield member 101a configured, the second mounting portion 101b on the upper side of the portion of FIG. 3 in the second inner shield member 101b ₁ is provided. That is, a portion corresponding to the second attachment portion is provided in the lower portion of FIG. 3 in the first inner shield member 101a, and the first attachment portion is provided in the lower portion of FIG. 3 in the second inner shield member 101b. A portion corresponding to is provided. The first inner shield member 101a and the second inner shield member 101b are arranged with respect to the central axis of the measurement tube 12 in the flow path direction.

  Inside the inner shield member 101, electrodes 102a and 102b and electrode substrates 103a and 103b are accommodated. Therefore, in order to connect to the excitation substrate 42, it is necessary to route the electrode cables 115a and 115b from the electrode substrates 103a and 103b to take them out.

  As shown in FIG. 4, each of the first inner shield member 101a and the second inner shield member 101b has a first sub-slit 101c and a second sub-slit 101d for routing the electrode cables 115a and 115b on its upper surface. is doing. As described above, since the first inner shield member 101a and the second inner shield member 101b have the same structure, both the first sub slit 101c and the second sub slit 101d are provided. Yes. In the example shown in FIG. 4, the first inner shield member 101a and the second inner shield member 101b have linear first sub-slits 101c and second sub-slits 101d in the y direction, respectively. It has a generally U-shaped shape. As described above, the first inner shield member 101a and the second inner shield member 101b in the present embodiment are provided with the same structure symmetrically with respect to the central axis of the measuring tube 12. Accordingly, the first sub-slit 101c and the second sub-slit 101d are provided at the center in the flow path direction of the first inner shield member 101a and the second inner shield member 101b, respectively.

  The slit portion 101e is configured by combining the first sub-slit 101c and the second sub-slit 101d to form one slit. In this way, by forming the slit portion 101e over the first inner shield member 101a and the second inner shield member 101b, a larger operation area can be obtained when the electrode cables 115a and 115b are pulled out from the inner shield member 101. The operability of the electrode cables 115a and 115b can be improved. In particular, when assembling the first inner shield member 101a and the second inner shield member 101b, the electrode cables 115a and 115b are assembled while being inserted into the slit portion 101e, so that the electrode cables 115a and 115b are placed outside the inner shield member 101. It can be pulled out easily.

  The electromagnetic flow meter is desired to be as small as possible, and accordingly, the intermediate shield member 112 is preferably as small as possible. When the intermediate shield member 112 is made smaller, the distance between the upper intermediate shield member 112b and the inner shield member 101 becomes smaller, but the electrode cables 115a and 115b are intermediated through the gap between the intermediate shield member 112 and the inner shield member 101. It is necessary to draw out to the outside of the shield member 112.

  In the present embodiment, as shown in FIG. 4, the bent portion 112c has a slit in the y direction at a position overlapping the slit portion 101e in the x direction, rather than both ends in the longitudinal direction of the slit portion 101e. What is necessary is just to be comprised so that it may not protrude toward the center side of the part 101e. In this case, the electrode cables 115a and 115b can be prevented from being sandwiched between the inner shield member 101 and the bent portion 112c, and a space for routing the electrode cables 115a and 115b can be easily secured. More preferably, the end of the bent portion 112c protrudes to a position that coincides with the end of the slit portion 101e. Accordingly, the electrode cables 115a and 115b drawn out from the slit portion 101e are interposed between the inner shield member 101 and the bent portion 112c while securing a width for screw-fixing the upper intermediate shield member 112b with respect to the bent portion 112c. It can prevent being pinched. In the present embodiment, the entire bent portion 112c in the x direction is provided so as to protrude inward so that the end portion in the y direction does not overlap the end portion of the slit portion 101e.

  In this way, the end portion in the y direction of the bent portion 112c protrudes to a position where it does not overlap the end portion of the slit portion 101e, so that the routing space provided between the end portion of the bent portion 112c and the upper portion of the slit portion 101e. Can be used to route the electrode cable. As described above, even when a high magnetic permeability material such as permalloy is arranged in the central portion on the surface of the upper intermediate shield member 112b on the measuring tube 12 side, the upper intermediate shield member 112b is routed between the both sides and the bent portion 112c. Since a space can be secured, a space for routing the electrode cable can be suitably secured. In the present embodiment, the flat upper intermediate shield member 112b is placed and fixed above the bent portion 112c of the lower intermediate shield member 112a, so that the electrode cable routing space can be easily configured. can do.

  Moreover, it is preferable that the end surfaces (electrode cable mounting surfaces) of the electrode substrates 103a and 103b on the side to which the electrode cables 115a and 115b are connected are inside the both ends of the slit portion 101e. As a result, the electrode cables 115a and 115b can be easily pulled out from the slit portion 101e, and the electrode cables 115a and 115b are less likely to come into contact with the end portion of the slit portion 101e. It becomes difficult to apply a load to 115a and 115b.

  FIG. 4 shows a state in which a part of the electrode substrates 103a and 103b arranged so that the mounting surface of the electrode cable is positioned inside the slit end portion when the slit is viewed from the upper surface is shown.

  FIG. 5 shows a cross-sectional view along the flow path direction of the electromagnetic flowmeter according to the present embodiment. As shown in FIG. 5, the electrode cables 115 a and 115 b are pulled out from the slit portion 101 e of the inner shield member 101, pulled upward through the gap between the inner shield member 101 and the intermediate shield member 112, and the excitation substrate 42. Are connected to connectors 43 and 44 respectively. Here, as shown in FIG. 3, the connectors 43 and 44 of the excitation substrate 42 are arranged side by side in the y direction. As described above, by arranging the connectors 43 and 44 of the excitation substrate 42 in the y direction, it is possible to form an accommodation state in which the two electrode cables 115a and 115b are accommodated side by side. Thereby, it is possible to unify the way of routing the electrode cables 115a and 115b, and to reduce the variation between individual products due to the variation in the arrangement of the electrode cables 115a and 115b. Therefore, variations such as the influence of radiation noise on the electrode cables 115a and 115b can be reduced, and variations in detection accuracy can be reduced.

  It demonstrates in detail using the block diagram of the electromagnetic flowmeter 1 which concerns on this embodiment shown in FIG. In FIG. 6, a display control circuit unit 40a formed on the display control board 40, a control circuit unit 41a formed on the control board 41, an amplification circuit part 42a and an excitation circuit part 42b formed on the excitation board 42, ,It is shown.

  The amplifier circuit unit 42a is connected to the electrode substrates 103a and 103b via the electrode cables 115a and 115b. As described above, the control circuit unit 41a controls the display control circuit unit 40a and the excitation circuit unit 42b based on the signal output from the amplification circuit unit 42a. The excitation circuit unit 42b controls the excitation current for the excitation coil 109 by a control signal from the control circuit unit 41a.

  As described above, the electromotive force generated between the electrodes 102a and 102b is extracted by the electrode cables 115a and 115b and amplified by the amplifier circuit on the excitation substrate 42, thereby measuring the flow rate of the fluid to be measured. At this time, for example, it is preferable to reduce the influence of the stray capacitance C generated in the electrode cables 115a and 115b as much as possible. However, the influence of the stray capacitance C is considered in advance by reducing the variation between individual products. It becomes possible to measure the flow rate. If the method of routing the electrode cables 115a and 115b in this embodiment is adopted, it is possible to reduce the variation of the stray capacitance between the individual products due to the variation of the arrangement of the electrode cables 115a and 115b and the influence of the radiation noise, which is preferable. is there.

(Second Embodiment)
Hereinafter, an electromagnetic flowmeter according to a second embodiment of the present invention will be described. Since the basic configuration is the same as that of the first embodiment, only different parts will be described.

  FIG. 7 illustrates the intermediate shield member 112 in the electromagnetic flow meter according to the second embodiment of the present invention. In the present embodiment, as shown in FIG. 7, the bent portions 112 c on both sides of the intermediate shield member 112 cover either the upstream surface or the downstream surface of the slit portion 101 e on the upper surface of the inner shield member 101. And a restricting portion 112d formed to protrude inward. The restricting portion 112d is configured so that the drawing direction of the electrode cables 115a and 115b drawn from the slit portion 101e can be restricted to either the upstream side or the downstream side of the measuring tube 12 by the restricting portion 112d. And projecting to a position overlapping in the x direction. Thereby, the variation in the arrangement of the electrode cables 115a and 115b in the electromagnetic flow meter can be reduced. For this reason, it is possible to reduce the influence of radiation noise on the electrode cables 115a and 115b, and to reduce variations in detection accuracy.

  In the present embodiment, as shown in FIG. 7, by providing the restriction portions 112d of the bent portions 112c on both sides of the intermediate shield member 112 so as to be aligned on the upstream side or the downstream side of the measurement tube 12, the electrode cable 115a is provided. However, it is not always necessary to provide the bent portions 112c on both sides of the intermediate shield member 112. If it is sufficient to restrict any one of the electrode cables 115a and 115b drawn out from the slit portion 101e to the upstream side or the downstream side due to the characteristics of other structures or the electrode cables 115a and 115b, the restriction portion 112d is provided. What is necessary is just to provide in either of the bending parts 112c of both sides.

(Third embodiment)
Hereinafter, an electromagnetic flow meter according to a third embodiment of the present invention will be described. Since the basic configuration is the same as that of the first embodiment, only different parts will be described.

  An electromagnetic flow meter according to a third embodiment of the present invention will be described with reference to FIG. FIG. 8A is a top view showing a state in which the control unit 50 is removed from the electromagnetic flow meter. FIG. 8B shows a cross-sectional view along the flow path direction of the electromagnetic flow meter according to the third embodiment. As shown in FIGS. 8A and 8B, claw members 121 and 122 for hooking the electrode cables 115 a and 115 b drawn from the slit portion 101 e of the inner shield member 101 are provided inside the case body 10. It has been.

  By hooking the electrode cables 115a and 115b on the claw members 121 and 122, variations in the arrangement of the electrode cables 115a and 115b in the electromagnetic flow meter can be reduced. For this reason, it is possible to reduce the influence of radiation noise on the electrode cables 115a and 115b, and to reduce variations in detection accuracy.

  The electrode cables 115a and 115b are both hooked on one of the claw members 121 and 122, and a cable for supplying an excitation current to the excitation coil 109 is hooked on the other claw member. May be.

DESCRIPTION OF SYMBOLS 10 Case body 11 Outer shield member 12 Measuring tube 13 Base 14 Sealing member 20 Display part 30 Operation part 40 Display control board 41 Control board 42 Excitation board 43, 44, 45 Connector 101 Inner shield member 102 Electrode 103 Electrode board 104 Substrate holder DESCRIPTION OF SYMBOLS 105 Convex part 106 Main body part 107 Holding part 108 Iron core part 109 Excitation coil 110 Magnetic field adjustment member 111 Copper foil seal 112 Intermediate shield member 115 Electrode cable

Claims (13)

A measuring tube having a flow path through which the fluid to be measured flows;
An electrode for extracting an electromotive force generated in the flow path;
An electrode substrate that outputs a signal based on the electromotive force extracted by the electrode;
An electrode cable for transmitting the signal output from the electrode substrate;
An inner shield member covering the measuring tube;
With
Inside the space covered with the inner shield member, the electrode, the electrode substrate, and the electrode cable are arranged,
The inner shield member has a slit portion for pulling out the electrode cable on an upper surface thereof. The inner shield member includes a first inner shield member having a first sub slit and a second inner shield member having a second sub slit,
The electromagnetic flowmeter according to claim 1, wherein the slit portion is configured by combining the first sub-slit and the second sub-slit.   The first inner shield member and the second inner shield member are formed with a U-shaped upper surface to form the first sub-slit and the second sub-slit. 2. The electromagnetic flow meter according to 2. An intermediate shield member configured to cover the inner shield member;
4. The electromagnetic flow meter according to claim 1, wherein the intermediate shield member has a bent portion that is bent in parallel with an upper surface of the inner shield member. 5.   The bent portion is configured such that an end portion of the bent portion that overlaps the slit portion in the flow channel direction does not protrude toward the center of the slit portion from the end portion of the slit portion. The electromagnetic flow meter according to claim 4, wherein the electromagnetic flow meter is provided.   The bent portion has a restricting portion that protrudes toward the center of the slit portion so as to cover either the upstream surface or the downstream surface of the slit portion on the upper surface of the inner shield member. The electromagnetic flow meter according to claim 4 or 5. A case body that houses at least the measurement tube and the inner shield member;
The claw member for hooking the electrode cable pulled out from the slit portion of the inner shield member is provided inside the case body, according to any one of claims 1 to 6. The described electromagnetic flow meter.   The electromagnetic flowmeter according to claim 1, wherein the inner shield member is made of a nonmagnetic material.   9. The electromagnetic flowmeter according to claim 1, wherein an end surface of the electrode substrate on a side to which the electrode cable is connected is located on an inner side than both end portions of the slit portion. The electrode is a convex portion projecting a part of the electrode toward the electrode substrate side, and has a convex portion that electrically connects the electrode and the electrode substrate,
10. The electromagnetic flowmeter according to claim 1, wherein the convex portion goes around the outside of the electrode substrate and is fixed to the electrode substrate. 11.   An inner shield member provided around a measurement pipe of an electromagnetic flow meter, wherein the inner shield member has a slit portion on an upper surface. The inner shield member includes a first inner shield member having a first sub slit and a second inner shield member having a second sub slit,
The inner shield member according to claim 11, wherein the slit portion is configured by combining the first sub-slit and the second sub-slit.   The inner shield member according to claim 12, wherein the first inner shield member and the second inner shield member are formed in a U-shaped upper surface.

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