JP2947634B2 - Electromagnetic flow meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disposable electromagnetic flow meter for measuring medicines, chemicals, fertilizers, pesticides and the like.

[0002]

2. Description of the Related Art Electromagnetic flowmeters are widely used for industrial flow measurement. However, since they are intended for long-term outdoor use, the flow detection unit has a complicated structure such as a metal case from the viewpoint of environmental resistance. It is expensive. When measuring chemicals, an expensive metal such as platinum is used for a liquid contact part in order to secure long-term corrosion resistance. Therefore, the flow rate measurement unit is expensive, from 100,000 yen to several hundred thousand yen.

On the other hand, for chemicals and agricultural chemicals, disposable flowmeters are required for safety and hygiene in order to avoid the mixing of chemicals and to save time for cleaning. However, none of the liquid-contacting parts was so inexpensive as to be disposable.

[0004]

In recent years, mixing of chemicals and
In order to improve the performance (accuracy of quantity / time) of spraying / injection / transportation, a flowmeter for measuring a flow rate is required.

[0005] However, from the viewpoint of ease of use and safety, the liquid contact portion is required to be disposable, so that the flow rate detecting portion must be inexpensive. Accordingly, it is an object of the present invention to provide an electromagnetic flowmeter which has a structure in which only the liquid contact portion is disposable and which can be manufactured at a low cost of several hundred yen.

[0006] Regarding chemical resistance, the use time can be shortened to about one day by disposable, and sufficient chemical resistance can be ensured within the use time without using expensive noble metals for electrodes and the like. .

[0007]

In order to achieve the above object, an electromagnetic flowmeter according to the present invention comprises an electrode (E) for extracting a flow signal and a hose for flowing a fluid to a meter tube (T) integrally formed of plastic. VH) and a disposable detector (S) incorporating a ground pipe (G) serving also as a ground electrode, and a coil (C) for generating a magnetic field.
_1, C ₂ ), magnetic poles (M ₁ , M ₂ ) for applying a magnetic field generated by the coil to the fluid, yokes (Y ₁ , Y ₂ ), coils (C _1, C ₂ ), electrodes (E), It has a wire (W) for making an electrical connection to the ground pipe (G) and a clamp (K) for holding the detector (S).

The magnetic pole (M₁, M_Two) To the tip
And the magnetic pole (M ₁, M_Two) Tip
It is effective to provide a conical recess (TA) into which
You.

[0009]

When the detector is held by the clamp, the electrode and the ground electrode are electrically connected. When an exciting current is applied to the coil, a magnetic field is applied to the fluid via the magnetic poles and the yoke, and a signal voltage corresponding to the flow velocity is induced at the electrodes, and is taken out through the wiring of the clamp. When used for medical infusion devices,
Remove the detector and hose after use and discard.

In the case where the tip of the magnetic pole is pointed and the meter tube is provided with a conical recess, the tip of the magnetic pole fits into the conical recess when the detector is held by the clamp. Positioning is performed, and the relative position between the flow path and the magnetic field is determined.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment shown in the drawings, T is a meter tube integrally formed of an electrically insulating plastic, having a fluid passage formed in the center thereof and having a conical shape perpendicular to the fluid passage. Is formed.

Numeral E denotes a nail-shaped electrode for extracting a signal, and G denotes a ground pipe which also serves as a connection fitting of a hose VH for flowing a fluid and a ground electrode. The electrode E is made of SUS316, and the ground pipe is formed by cutting a tube made of SUS304 to 316. Pressing and fixing the electrode E and the ground pipe G to the meter tube T helps to reduce the assembly cost.

[0013] K is a clamp, which has a
A spring D that exerts a clamping force with the spring body B and a leaf spring
Electrode contact EP to be brought into contact with the head of the electrode E₁
~ EP_TwoAnd formed by pressing a thin spring plate
Ground contact GP that should contact ground pipe G
₁~ GP_TwoAnd an exciting coil C for generating a magnetic field _1,
C_TwoAnd these electrode contacts GP₁~ GP_Twoand
Coil C₁~ C_TwoW electrically connected to each other
A cable CB for connecting the wiring W to the amplifier A;
Il C_1,C_TwoLocated in the center of the (permalloy
High-permeability material or semi-hard magnetic material (such as ferritic SUS)
Pole M with a conical tip₁, M_TwoAnd (Iron
Permalloy / Ferrite SUS / Ferrite SU
S. A plate made of high permeability material (such as amorphous metal)
Yoke Y bent in a circle or U-shape as shown₁, Y_TwoWhen
Consists of York Y₁, Y_TwoConstitutes a return magnetic path.

The magnetic poles M ₁ and M ₂ are fixed to the yokes Y ₁ and Y ₂ by caulking or the like, respectively. The yokes Y ₁ and Y ₂ are fixed to the inner surface of the clamp body B. The amplifier A increases the flow rate signal generated at the electrode E and supplies an exciting current to the coils C ₁ and C ₂ .

Coil C ₁ , C
_{In the case of 2,} the clamp K is provided so that the cost of the disposable detector S is reduced, and the troublesome wiring W is provided on the clamp K so that the detector S in the disposable portion has no wiring.

As shown in FIGS. 1B and 5, the detector S is held by the clamp K such that the tips of the magnetic poles M ₁ and M ₂ are fitted into the conical recess TA of the meter tube T. The orientation of the magnetic poles M ₁ , M ₂ and the electrodes E, E is exactly 90
Will be maintained every time.

Further, the yokes Y ₁ and Y ₂ and the sharp magnetic poles M ₁ and M ₂ enhance the excitation efficiency and reduce the power consumption.

[0018]

According to the present invention, as described above, the disposable detector (S) has two electrodes (E) and a ground pipe (G) press-fitted into a meter tube (T) made of plastic and integrally molded. Due to the fixed and simple structure, the production cost of this part can be reduced, and an inexpensive electromagnetic flow meter that can be used for the disposable detector (S), which is a liquid contact part, can be realized.

The magnetic pole (M₁, M_Two) At the end
Fitting into the conical recess (TA) of the tube
With the operation of holding the detector (S) on the clamp (K),
Pole (M ₁, M_Two) And electrode (E) are accurately positioned
In other words, the measurement accuracy, particularly the accuracy of a small flow rate, can be improved.

Furthermore, power consumption can be reduced by using the yokes (Y ₁ , Y ₂ ) and the magnetic poles (M ₁ , M ₂ ).

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional front view of a detector, and FIG. 1B is an overall perspective view of an embodiment of the present invention.

FIG. 2 is a vertical sectional side view of a detector used in the embodiment of the present invention.

FIG. 3 is a plan view of a detector used in the embodiment of the present invention.

FIG. 4 is a partial longitudinal side view of a clamp according to the embodiment of the present invention.

FIG. 5 is a partially longitudinal side view showing a main part of the embodiment of the present invention, showing a state in which a detection unit is held by a clamp.

FIG. 6 is an electric circuit diagram of the embodiment of the present invention.

[Explanation of symbols]

C _1, C ₂ coils E electrode G ground pipe K clamp M _1, M ₂ pole S detector T meter tube VH hose W wiring Y _1, Y ₂ York

Claims (2)

(57) [Claims] 1. A meter pipe (T) integrally formed of plastic incorporates a ground pipe (G) which also serves as a connection fitting for an electrode (E) for extracting a flow signal and a hose (VH) for flowing a fluid and a ground electrode. disposable detector and (S), the magnetic pole for applying a magnetic field and a coil (C _1, C ₂₎ generated in the coil that generates a magnetic field in the fluid (M _1, M ₂₎ and the yoke (Y _1, Y ₂ ) and coil (C1 _,
C ₂ ), an electrode (E), an electric wire (W) for making an electrical connection to the ground pipe (G), and a clamp (K) for holding the detector (S). . _2. The tip of the magnetic poles (M ₁ , M ₂ ) is pointed, and the meter tube (T) is provided with a conical recess (TA) into which the tips of the magnetic poles (M ₁ , M ₂ ) are fitted. The electromagnetic flowmeter of claim 1.