JPS5840687B2 - fluid flow meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry impeller type fluid flowmeter that rotates an impeller using the energy of a fluid and measures the flow rate of the fluid in an integrated manner based on the number of revolutions of the impeller.

A conventional fluid flowmeter of this type is configured as shown in FIG. 1, for example, and includes an integration indicating mechanism A, an intermediate gear mechanism B, and a measuring section C.

The intermediate gear mechanism B and the measuring section C are immersed in the fluid within the meter casing 1, and the other indicator mechanism A is interposed and is blocked from the fluid by the shielding plate 2.

The measuring part C is rotatably supported by a support shaft 6 screwed upright at a position 1 approximately midway between the fluid inlet 3 and fluid outlet 4 of the meter casing 1 and at the center of the bottom inside the impeller casing 5. It has an impeller 7.

Reference numeral 8 designates several inlets radially drilled in the casing 5, and above the inlet 8, a plurality of similarly drilled outlets 9 are provided in a direction different from the radial direction. ing.

The fluid flows from the inlet 3 of the meter casing 1 to the inlet 8 of the impeller casing 5, flows into the casing 5, and rotates the impeller 7.

Part 1. Then, it is pushed out by the impeller 7, flows out from the outlet 9, and further flows to the outlet 4 of the meter casing 1.

The flow rate of the fluid can be determined by detecting the rotation speed of the impeller 70, and the rotation speed is transmitted to the intermediate gear mechanism B located above the impeller 70 via the impeller shaft 10, where it is amplified and shut off. The signal is transmitted to the gear group 11 of the indicating mechanism A via the plate 2.

Indication mechanism A is meter casing 1, shielding plate 2.01J
The impeller 70 rotation speed transmitted to the gear group 11 is transferred to the auxiliary wheel 1 by intervening in a sealed body of the upper casing 14, which is constituted by the ring 12 and the transparent plate 13, and is isolated from outside air and fluid.
5. The information is transmitted to the display wheel 16, etc., and the flow rate of the fluid is displayed digitally (or with a pointer).

The displayed flow rate can be read by opening the opening/closing lid 17 provided on the top surface of the meter casing 1 and looking through the see-through plate 13.

However, in this type of flowmeter, when there is a temperature difference between the inside of the upper casing 14 and the outside air, the inner surface of the see-through plate 13 becomes cloudy, making it difficult to visually read the flow rate.

In addition, if this flowmeter is used to measure liquid, the intermediate gear mechanism B may be corroded by contaminants such as dust in the liquid or by chemical action, which may cause failure, and the usage time may be shortened. With the passage of time, moisture penetrates into the upper casing 1 from the intermediate gear mechanism B side of the blocking plate 2 whose bottom is made of synthetic resin or casting, etc., causing fogging of the transparent plate 13 and indicating mechanism A.
was causing the malfunction.

Conventionally, methods to prevent these problems include injecting inert gas into the upper casing 14, omitting the intermediate gear mechanism B, and connecting the upper surface of the impeller 7 and the corresponding gear of the indicating mechanism A. Although there is a method of embedding a magnet to directly transmit the rotation speed of the impeller 7 to the indicating mechanism A, it is impossible to prevent liquid from entering the upper casing 14, and improvements are needed.

The present invention has improved the above-mentioned drawbacks of the conventional technology, and has made the integration indicator mechanism double-sealed using an upper casing made of Atsunai synthetic resin and a thin-walled metal casing. It is an object of the present invention to provide a fluid flowmeter of this type at a low cost, which prevents clouding of the plate and failure of the indicating mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be explained below according to embodiments shown in the drawings.

In FIG. 3, 21 is a meter casing,
A portion that accommodates a measuring section C consisting of an impeller casing 26 having an inlet 22 and an outlet 23 on both sides, and a boss portion 24a of an impeller 24 rotatably supported in the central lower half via a pivot shaft 25. 27, and an accommodating portion 28 for the integration instruction mechanism A is integrally formed in the upper center portion.

The meter casing 21 is divided into upper and lower parts by a partition wall 29, and a hole 301/2m in the center of the partition wall 29 is fitted with an outer circumferential step 26a of the impeller casing 26.

The inflow port 22 communicates with the lower side of the partition wall 29, and the outflow port 2
3 communicates with the upper side of the partition wall 29.

The impeller casing 26 has a bottomed cylindrical shape with an open upper part, and has a plurality of fluid inlet ports 31 formed approximately tangentially at equal intervals around the lower part, and a plurality of fluid guide ports 31 around the upper part. The outlets 32 are formed tangentially and at equal intervals in antisymmetrical relation to the fluid inlet 31 .

A driving magnet 3 is attached to the upper end of the boss portion 24a of the impeller 24.
3 is buried.

Referring to FIG. 3, reference numeral 34 denotes a bottomed cylindrical upper casing made of thick-walled synthetic resin with an opening at the top. The bottom plate 34a is fitted so as to be completely separated from the fluid in the measuring part C, and the bottom plate 34a closes the upper opening of the impeller casing 26.

The integration instruction mechanism A includes a pilot pointer shaft 36 in which a driven magnet 35 facing the drive magnet 33 of the impeller 24 is buried in its lower end, a reduction gear group 37 that meshes with and interlocks with the pilot pointer shaft 36, and this reduction gear. Group 3
7, and these are mounted between a protective case 39 and an indicator cover plate 40.

Incidentally, a display window 41 is provided in a part of the indicator cover plate 40, that is, in the part of the counter number wheel 38.

The integration indicating mechanism A attached to the protective case 39 and the indicating cover plate 40 is fitted and housed in a bottomed cylindrical thin metal casing 42 with an open top. A see-through plate 43 is provided.

That is, the see-through plate 43 is placed on the indicator cover plate 40 via the annular seal member 44, and the upper periphery of the thin metal casing 42 is bent inward and caulked to press down the upper periphery of the see-through plate 43. As a result, the integration instruction mechanism A housed within the thin metal casing 42 is sealed and integrated into a unit.

The thin metal casing 42 is fitted into the above-mentioned upper casing 34 made of thick synthetic resin.

In short, the integration indicator mechanism A is doubly surrounded by a thick-walled synthetic resin upper casing 34 and a thin-walled metal casing 42 that is a sealed unit, and is completely separated from the fluid in the metering section C for measurement. It is housed in the upper meter casing 21 of section C.

In FIG. 3, reference numeral 45 denotes a fastening ring fastened to the upper opening of the meter casing 21, and an opening/closing lid 46 is attached thereto.

This fastening ring 45 is for tightening and fixing the upper casing 34 and the thin metal casing 42 inside the meter casing 21, and of course also presses the impeller casing 26 against the partition wall 29 to move the inside of the meter casing 21 up and down. The area is divided into two areas.

The thin metal casing 42 is filled with clean, moisture-free air or inert gas.

As explained above, in this invention, the accommodating part for the integration indicating mechanism is integrally formed in the upper central half of the meter casing which accommodates the measuring part in the lower central half. It is possible to eliminate the complication of the structure for joining the upper and lower parts and the deterioration of the sealing performance of the joint, which would occur when the upper and lower parts are separated.

In addition, the integration indicator mechanism is magnetically interlocked with the impeller of the metering section, and is housed in a bottomed cylindrical thin-walled metal casing with a see-through plate on top to form a sealed unit. , no outside air or moisture can enter,
In particular, a metal casing can prevent fluid from penetrating even under high-pressure conditions, and since it is thin, it can be made lightweight and inexpensive, and it can be easily crimped to connect see-through plates.

Furthermore, a bottomed cylindrical upper casing made of thick-walled synthetic resin with an opening at the top is fitted into the central upper half of the meter casing to completely separate it from the fluid in the metering section.
The thin-walled metal casing was fitted into this upper casing, and the integration indicator mechanism was double-sealed and housed in the meter casing, so that the thick-walled synthetic resin upper casing However, the thin metal casing is reinforced and protected, and the fluid pressure can be prevented from directly acting on the thin metal casing to cause deformation such as bulging, and the overall cost can be reduced.

In other words, thicker metal materials are not only expensive but also have poor workability and are difficult to form into sealed units, but thinner metal materials are cheaper and easier to process and form into sealed units. On the other hand, it is inexpensive and easy to mold, but fluid permeates under high pressure.If you combine these as described above, you can obtain a fluid flowmeter that is inexpensive, has no clouding of the see-through plate, and has excellent durability with few failures. be able to.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a conventional fluid flow meter, FIG. 2 is a cross-sectional view showing a measuring section thereof, and FIG. 3 is a vertical cross-sectional view of the same flow meter according to the present invention. 12...OIJ song 43...See-through plate, 34...Upper casing, 42...
Metal casing, A...Flow rate integration indicator mechanism.

Claims (1)

[Claims] 1 It has an inlet and an outlet on both sides, has a part in the lower center half that accommodates a measuring section made of an impeller casing that rotatably supports an impeller, and has an integration indicator mechanism in the upper center half. a meter casing integrally formed with a housing section, and a thick bottomed cylindrical tube having an opening at the top and fitted into the central upper half of the meter casing so as to be completely separated from the fluid in the metering section. It has an upper casing made of synthetic resin and an integration indicating mechanism that is magnetically interlocked with the impeller of the measuring section, and the upper surface is sealed with a see-through plate through a sealing member 1 to form a unit. A bottomed cylindrical thin-walled metal casing that fits into the casing, and a fastening ring with an opening/closing lid that is fastened to the upper opening of the meter casing and fixes the upper casing and the thin-walled metal casing inside the meter casing. The integration indicating mechanism is double surrounded by a thick-walled synthetic resin upper casing and a thin-walled metal casing formed into a sealed unit, and is housed in the meter casing above the measuring section. Fluid flow meter.