JPH01105118A - Turbine flowmeter - Google Patents

Abstract

PURPOSE:To improve the balance of an impeller and to measure a flow rate with high accuracy by forming a magnetic material film magnetized in a specific magnetism pattern on the surface of the hub of the impeller facing a pickup. CONSTITUTION:Fluid to be measured passes between blades 2b of the impeller 2 along the outer periphery of an upstream cone 5 and flows along the outer periphery of a downstream cone 6. The blades 2b are pressed downstream and pressed upstream with pressure admitted to a gap B from a back pressure intake 14 provided on the cone 6. The impeller 2 is supported floating between the upstream and downstream cones 5 and 6 and rotates according to the flow rate. The impeller 2 is constituted by forming the uniform magnetic material film 3 on the hub 2a, so it rotates stably. Its rotation is detected by the pickup 13 facing the magnetic material film 3 and pulses outputted by the pickup 13 are amplified and supplied as a flow rate measurement signal to a flow rate indication part. Further, the impeller 2 rotates while well balanced, so the pickup 13 outputs the stable pulses.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a turbine-type flowmeter, and more particularly to a turbine-type flowmeter constructed so that impellers are manufactured in a well-balanced manner and flow rates can be measured with high precision.

Conventional technology In general, a turbine flowmeter that measures the flow rate of a fluid to be measured passing through a flow path uses, for example, an impeller having a plurality of blades around the outer circumference of a hub that can be freely rotated between an upstream cone and a downstream cone. There is a known structure in which the flow rate is measured by supporting the impeller and detecting the rotation of the impeller. In this type of turbine-type yl meter, for example, a plurality of magnets are provided at predetermined intervals on the hub of the impeller, and a magnetic sensor as a pickup is provided on the upstream cone or the downstream cone to face the magnets. When the magnet passes by due to the rotation of the impeller, an output signal is obtained from the magnetic sensor.
Flow rate measurement is performed based on this output signal. Further, the magnet is embedded in a recess provided in the hub of the impeller and is integrated with the impeller.

Problems to be Solved by the Invention However, in conventional turbine flowmeters, at least two or more magnets are provided on the impeller in order to obtain more output signals or to balance the impeller.
The length of each magnet varies by 1 m, and the positional accuracy of the recess provided in the hub also varies. Furthermore, in the conventional case, it is difficult to press-fit the magnet into the recess of the hub, so the magnet is fixed with adhesive or the like, and a clearance is required between the recess and the magnet. Therefore, in conventional turbine-type flowmeters, it is difficult to arrange the magnet at a predetermined mounting position with high precision, making it impossible to obtain a well-balanced impeller, and the rotation of the impeller becomes unstable. There was a problem in that it was difficult to improve the accuracy of flow rate measurement.

Therefore, the present invention aims to solve the above problems.

Means and Effects for Solving the Problems The present invention provides the above-mentioned turbine flowmeter, in which a magnetic film magnetized in a predetermined magnetization pattern is formed on the surface of the hub of the impeller facing the pickup. The impeller's balance has been improved to allow for highly accurate flow measurement.

Embodiment FIGS. 1 and 2 show an embodiment of a turbine flowmeter according to the present invention. In both figures, a turbine flow meter 1 is provided in the middle of a pipe through which a fluid to be measured is fed, and measures the flow rate of the fluid to be measured flowing through a flow path of the pipe.

2 is an impeller, and a plurality of blades 2b are provided radially around the outer periphery of a hub 2a. Further, a magnetic material 1113 is formed on the side surface 2C of the hub 2a by printing or the like, and the magnetic material film 3
For example, the pattern is as shown in Figure 2, and the left half is made of Ni.
The right half is magnetized to the S pole.

Further, the magnetic film 3 is applied to the entire surface of the side surface 2C with a uniform film thickness. Therefore, the impeller 2 is manufactured with extremely good balance.

The impeller 2 is rotatably supported by a shaft 4 inserted through a central hole 2d of the hub 2a. Therefore, the fluid to be measured flows in the direction of the arrow (shown in FIG. 1), and the blade 2b of the blade 112
When the impeller 2 passes through the gap, the impeller 2 rotates according to the flow rate.

Note that the impeller 2 does not have a magnet buried in the side surface 2c of the hub 2a, but instead uses a uniform magnetic material l113 that is placed in the hub 2 in a well-balanced manner.
Since it is formed on the side surface 2G of a, the minute flow rate area rotates stably according to the flow rate up to the large flow area I.

Further, the shaft 4 is provided between an upstream cone 5 and a downstream cone 6, and the hub 2a of the impeller 2 supported on the shaft 4 is connected to the upper and downstream cones 5 through gaps A and B. Opposed to 6. The upstream cone 5 has a rod 7 extending upstream, and the rod 7 is supported by an upstream support member 8 and fixed by tightening a nut 9. Also, F flow side cone 6
has a rod 10 extending downstream, and the rod 10 is supported by a support member 11 on the downstream side and fixed by tightening a nut 12.

Reference numeral 13 denotes a pickup consisting of a magnetic sensor or the like, which is buried in a position facing the magnetic film 3 formed on the hub 2a through a gap A, that is, in the side surface 5a of the upstream cone 5. When the impeller 2 rotates, the pickup 13
N pole magnetized to 3.

Since the S poles pass alternately, a pulse is output according to the rotation speed at that time.

14 is a back pressure introduction hole, and the downstream area of the downstream cone 6 and the gap B
A hole is provided in the axial direction of the downstream cone 6 so as to communicate with the cone 6.

Next, the operation of the turbine flow meter having the above configuration will be explained.

When the fluid to be measured flows from the upstream side as shown by the arrow, the fluid to be measured flows along the outer periphery of the upstream cone 5 to the vane 2b of the vane 1112.
and flows downstream along the outer periphery of the downstream cone 6. The blade llI2 is pressed downstream of the blade 2b by the passage of the fluid m, but is pressed upstream by the upstream pressure introduced into the gap @B from the back pressure introduction hole 14. Therefore, the impeller 2 is supported in a floating state between the upper and downstream cones 5.6, and rotates in accordance with the flow rate of the fluid to be measured.

Incidentally, since the impeller 2 is formed by forming a uniform magnetic film 3 on the hub 2a, it has an extremely well-balanced configuration. Therefore, the impeller 2 can always rotate stably.

The rotation of the impeller 2 is detected by a pickup 13 facing the magnetic body WA3. The pulses output from the pickup 13 are amplified by an amplifier (not shown) and supplied to a flow rate indicator (not shown) as a flow rate measurement signal.

In addition, since the impeller 3 rotates stably in a well-balanced manner, the pickup 13 can output stable pulses.
Flow rate can be measured with higher accuracy.

Here, the manufacturing process for forming the magnetic film 3 on the impeller 2 will be explained. As shown in FIG. 3(A), first, the pigment 16 in the container 15 is mixed with the magnetic powder (for example, Ferrite magnetic material, etc.) 18 in the container 17. Next, Figure 3 (B), (
As shown in B'), the magnetic material 18 is printed by screen printing.
The mixed paint 19 is applied to the entire side surface 2C of the hub 2a.

In the screen printing process, first, as shown in FIG. 3(B), paint 19 is placed on screen 21 of plate 22, which is formed by stretching screen 21 on frame 20. screen 21
The portion except for the pattern corresponding to the side surface shape of the hub 2a of the impeller 2 is masked. Next, Figure 3 (B
As shown in '), the printing plate 22 is applied to the side surface 2C of the hub 2a, and the paint 19 is printed on the side surface 2C of the hub 2a by tracing the surface of the screen 21 with a squeegee or the like.

Then, by the above screen printing, the side surface 2C of the hub 2a is
The paint 19 uniformly printed on the entire surface of
, (D), it is fired in the firing process. As a result, the magnetic material gI3 having a thin and uniform thickness is formed on the hub 2a of the impeller 2.

Next, as shown in FIG. 2, the magnetic film 3 is magnetized, for example, so that the left half becomes the N pole and the right half becomes the S pole. In this way,
The impeller 2 has a uniform magnet formed on the entire surface of the side surface 2C of the hub 2a, resulting in a well-balanced configuration.

In addition, when magnetizing the magnetic film 3, W! The i pattern is the second
The magnets are not limited to the one shown in the figure, but may be magnetized in any pattern such that the north pole and the south pole alternately pass through the pickup 13. For example, as shown in FIG. 4, the magnetic film 3 may be magnetized with N poles and S poles at intervals of 90 degrees. Further, as shown in FIG. 5, in order to obtain more pulses, the magnetic material rIA3 may be magnetized alternately with N poles and S poles at intervals of 45 degrees.

Further, in the above embodiment, the magnetic film 3 is formed on the hub 2a of the impeller 2 by printing, but it may be formed by a manufacturing method other than printing. For example, there is a method of coating the side surface 2C of the hub 2a with a paint made by adding magnetic powder (for example, ferrite magnetic material, etc.) and an acrylic resin as a binder to an organic solvent.

In addition, as a manufacturing method other than the above for forming the magnetic film 3, CO or Fe is added to an N1-P plating solution and deposited at high temperature to form the magnetic film 3 on the side surface 2C of the hub 2a.
There is also a manufacturing method that involves plating.

Effects of the Invention As described above, the turbine flowmeter according to the present invention has a magnetic material that is magnetized in a predetermined pattern formed on the side surface of the hub of the impeller, so a plurality of magnets are embedded in the hub. Compared to conventional products, it is not affected by variations in the magnet itself or in the accuracy of magnet installation, and by providing a magnetic film with a uniform thickness, it is possible to manufacture a well-balanced impeller. The rotation of the impeller can be stabilized from a small flow rate range to a large flow rate range. Therefore, when measuring miscarriage,
It has features such as being able to obtain stable pulses from the pickup as the impeller rotates, making it possible to measure the flow rate with higher accuracy.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a turbine flowmeter according to the present invention, Fig. 2 is a front view of an impeller on which a magnetic film is formed, and Fig. 3 (
A) to (D) are diagrams for explaining the steps of printing a magnetic film, respectively, and FIGS. 4 and 5 are diagrams for explaining modified examples of the magnetization pattern. 1... Turbine flowmeter, 2... Impeller, 3...
Magnetic film, 4... Axis, 13... Pickup, 16
...Pigment, 18...Magnetic powder, 19...Paint. Patent applicant Tokiko Co., Ltd. Figure 1 Figure 3 [C1 Figure 3 - (Dl Procedural amendment dated October 27, 1985 1, Indication of case 1988 Patent application No. 122870 2, Title of the invention Turbine flow meter a Relationship with the case of the person making the amendment Patent applicant address 1-6-3 Fujimi, Yozaki-ku, Yozaki-shi, Kanagawa 210 Name (305) Tokico Co., Ltd. Representative Ko Kawago 4, Agent Address: 5-7-6 Kojimachi, Chiyoda-ku, Tokyo 102
, Detailed description of the invention in the specification subject to amendment. 7. Contents of the amendment In the specification, r(B')J written on page 7, line 7 and page 15, line 15 is corrected to r(C)J. ■ r(C) described on page 8, line 2 of the same. (D)” is corrected as r(D), (E)J. Procedure person 1] Correct trial (method) % formula % 1. Indication of case 1988 Patent No. 122870 2. Title of invention Turbine type flowmeter a Relationship to the case of the person making the amendment Patent applicant address 210 Kanagawa Address: 5-7-6 Kojimachi, Chiyoda-ku, Tokyo 102 1-6-3 Fujimi, Yotoge-ku, Yosaki-shi, Prefecture Name (305) Tokico Co., Ltd. Representative Kou Kawai 4 Address: 5-7-6 Kojimachi, Chiyoda-ku, Tokyo 102
, a column for a brief description of the drawings in the specification subject to amendment, and drawings. 7. Contents of amendment (1) In Specification 1, page 10, line 7 [Figure 3 (A
) to (D)J are corrected as "Fig. 3 (A) to (E)". ■Amend Figure 3 in the drawings as shown in the attached sheet. Figure 3b 2a (Dl

Claims (1)

[Claims] A turbine type having a plurality of blades on the outer periphery of a hub, an impeller rotatably supported in a flow path, and a pickup that detects the rotation of the impeller according to the flow rate of the fluid to be measured. A turbine-type flowmeter, characterized in that a magnetic film magnetized in a predetermined magnetization pattern is formed on the surface of the hub facing the pickup.