JP2003050143A - Single box-type tangential flow vane-wheel water meter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water meter in which water passed through an inflow-side nozzle acts efficiently on a vane wheel and which conforms to international standards. SOLUTION: A straightening member 40 is installed inside the inflow-side nozzle 11a at a lower case 10, so as to come into contact with its inner circumferential face. The straightening member is formed, e.g. into an angular tube shape, whose cross section is square or is in a rail shape, whose cross section is H-shaped. For example, hook pieces 40a.40b are formed at the straightening member, and the hook pieces are hooked on an entrance step part a at the inflow-side nozzle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single box tangential flow impeller water meter for measuring the flow rate of tap water.

[0002]

2. Description of the Related Art Conventionally, this type of water meter has a total length of 100 mm, which is called a short, and a total length of 165.
Some are called mm long.

In such a single-box tangential-flow impeller water meter, conventionally, a verification tolerance at each flow rate has been determined by the measuring method. It was required to be within the conventional test tolerance range shown in.

However, with the recent globalization, the international standard of the International Legal Metrology Organization (OIML) is adopted, and for example, the verification tolerance range is reduced from the frame shown by the solid line in FIG. 6 to the frame shown by the dotted line. Became.

However, some of the water meters manufactured up to now have flow rate-device difference curves as shown in FIG. 6, which satisfy the conventional test tolerance but do not satisfy the new international standard. . For this reason, it is necessary to improve the water meters that have been manufactured so far and create new water meters that meet international standards.

[0006]

Under such a demand, in a water meter generally called a short circuit having a total length of 100 mm, an inflow side nozzle has a circular cross section and a straight portion is short, so that a conventional water flow is complicated. Then, there was a problem that water did not work efficiently on the impeller. In particular, since the flow of water changes depending on various conditions, it does not always become constant and varies from measurement to measurement, and as shown in FIG. 6, the instrumental error performance is not stable especially in the small flow rate region.

Therefore, an object of the present invention is to make water that has passed through an inflow side nozzle act efficiently on an impeller, and to obtain a water meter that conforms to international standards.

[0008]

Therefore, the invention according to claim 1 is a single-box tangential flow impeller water meter.
A rectifying member is provided inside the inflow side nozzle of the lower case in contact with the inner peripheral surface.

The invention according to claim 2 is the single-box tangential flow impeller water meter according to claim 1, characterized in that the rectifying member is in the shape of a rectangular tube having a rectangular cross section.

The invention according to claim 3 is the single-box tangential flow impeller water meter according to claim 1, characterized in that the rectifying member has a rail-like shape with an H-shaped cross section.

According to a fourth aspect of the present invention, in the single-box tangential flow impeller water meter according to the first, second or third aspect, a rectifying member is hooked on the inlet step of the inflow side nozzle. , Is characterized.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a vertical cross section of a short type single box type tangential flow impeller type water meter according to the present invention.

Reference numeral 10 in the drawing is a lower case. An inflow side nozzle 11a and an outflow side nozzle 11b having a circular cross section are provided in the lower case 10 as a water flow port 11. The inlet side nozzle 11a is provided with a step a at the inlet to form a mouth b. In the illustrated example, as can be seen from FIG. 2, the mouth portion b and the inflow side nozzle 11a are provided slightly eccentric. And the step a
Then, the strainer 12 is mounted in the mouth b, and the strainer 12 is attached.

In the lower case 10, a horizontal installation support 13 is formed on the outer bottom surface so as to project in a cross shape, a pivot support 14 and a pivot nut 15 are provided at the center of the inner bottom surface, and a pivot 16 is set up.

In the lower case 10, an impeller 1 supported by a pivot 16 and having a magnet 17 above the impeller shaft is provided.
8 is rotatably accommodated, and the instruction unit 20 is assembled on the impeller 18 with the lower gasket 19 interposed therebetween. Then, a measuring chamber A having an inflow side nozzle 11a and an outflow side nozzle 11b is defined in the lower case 10, and the impeller 18 is housed therein.

The instruction unit 20 includes a register box 21, a lower base plate 22, an upper base plate 23, a window frame 24, a magnet gear 26 having a magnet 25, a gear train 27, and a pointer 2.
8. A glass plate 30 to be attached with the numeral wheel 29 and the O-ring 31 sandwiched therebetween is provided. Then, the magnet 25 is inserted between the bottom wall of the register box 21 and the magnet 1 of the impeller 18.
7 and the magnet coupling M is formed.

The upper gasket 3 is provided on the indicating unit 20.
The upper case 33 is covered with 2 in between and screwed to the lower case 10. A lid 35 is attached to the upper case 33 by a pin 34 so as to be vertically openable and closable.

Then, while removing foreign matter with the strainer 12, tap water flows into the measuring chamber A from the inflow nozzle 11a, rotates the impeller 18 according to the amount of water, and then flows out from the outflow nozzle 11b.

The rotation of the impeller 18 is transmitted to the indicating unit 20 via the magnetic coupling M, is transmitted via the gear train 27 to rotate the pointer 28, and is also a numeral wheel 29.
Is rotated, and the integrated flow rate value of the tap water that has passed through the measuring chamber A is displayed on the instruction unit 20.

By the way, also in this water meter, a rib-shaped upper resistor 37 extending in the radial direction is integrally and fixedly formed on the outer bottom surface of the register box 21. Further, the adjuster 38 is rotatably attached to the outer bottom surface of the fixing screw 3.
Fix with 9. Then, the water meter is adjusted so as to display an appropriate indication value according to the flow rate.

In the present invention, as shown in FIG.
The rectifying member 40 is provided in the inflow side nozzle 11 a of the lower case 10. Although not shown, the strainer 12 is housed in the mouth b after the rectifying member 40 is attached.

The rectifying member 40 is, for example, as shown in FIG. 3, formed into a rectangular tube having a rectangular cross section, one end thereof is straight along the step a, and the other end is along the inner peripheral surface of the measuring chamber A. It is formed by bending. Then, a pair of long latching pieces 40a is cut and raised at one end on one side and a pair of short latching pieces 40b is similarly cut and raised on the other side at the upper and lower sides. These hooking pieces 40a and 40b may be attached by welding or the like without being cut and raised.

In such a straightening member 40, the corner portion of the rectangular tubular portion is brought into contact with the inner peripheral surface of the inflow side nozzle 11a, the hooking pieces 40a and 40b are hooked on the step portion a, and The tips of the hooking pieces 40a, 40b are abutted against the inner circumference of the mouth portion b to prevent them from rotating and are housed in the inflow side nozzle 11a so as not to project into the measuring chamber A.

The rectifying member 40 is not limited to a rectangular tube having a rectangular cross section, and may be a rail having an H-shaped cross section as shown in FIG. 4, for example, by connecting plate members by welding or the like. Also in the case of this example, a pair of long hooking pieces 40a is provided above and below one end on one side.
A pair of short hooking pieces 40b is formed on the upper and lower sides of the other side. These hooking pieces 40a and 40b are provided integrally with the plate material forming the flow regulating member 40 so as to project therefrom.

Although not shown, both edges of the plate member are brought into contact with the inner peripheral surface of the inflow side nozzle 11a, so that the hooking pieces 40a.
0b is hooked on the stepped portion a, and the ends of the hooking pieces 40a, 40b are abutted against the inner circumference of the mouth portion b and housed in the inflow side nozzle 11a so as not to project into the measuring chamber A.

In this way, the water which has passed through the strainer 12 and flowed into the inflow side nozzle 11a is rectified by the flow regulating member 40.
It is possible to rectify and make uniform, effectively act on the impeller 18 to eliminate the variation in each measurement, and stabilize the instrumental error performance as shown in FIG. Thus, by adjusting the adjuster 38, it is possible to obtain a water meter that conforms to international standards.

Further, as described above, since the mouth portion b and the inflow side nozzle 11a are eccentric, the hooking pieces 40a, 40a.
When the tip of b is abutted against the inner circumference of the mouth b, the rectifying member 40
Can be stopped.

[0028]

As described above, according to the present invention, since the rectifying member is provided in the inflow side nozzle of the lower case so as to contact the inner peripheral surface, the rectifying member passes through the inflow side nozzle. The water can be rectified and made uniform, and can efficiently act on the impeller to eliminate variations between measurements and stabilize instrumental error performance. This makes it possible to obtain a water meter that meets international standards.

According to the invention of claim 2, the straightening member has a rectangular tubular shape with a square cross section, and according to the invention of claim 3, the straightening member has a rail shape with a H-shaped cross section to achieve the above effect. can do.

According to the fourth aspect of the present invention, since the flow regulating member is hooked on the inlet step of the inflow side nozzle, the flow regulating member can be prevented from coming out of the inflow side nozzle.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a short type single box type tangential flow impeller water meter according to the present invention.

FIG. 2 is a cross-sectional view at the position of the water outlet.

FIG. 3 is a perspective view of a flow regulating member provided in the inflow side nozzle.

FIG. 4 is a perspective view of another example of the flow regulating member.

5 is a diagram showing a flow rate-unit difference curve of the water meter shown in FIG.

FIG. 6 is a diagram showing a flow rate-unit difference curve of a water meter that conforms to a conventional standard.

[Explanation of symbols]

10 Lower case 11 water outlet 11a Inflow side nozzle 11b Outflow side nozzle 40 Straightening member a step b mouth A weighing room

Claims (4)

[Claims] 1. A single box type tangential flow impeller type water meter in which a flow regulating member is provided in contact with the inner peripheral surface in the inflow side nozzle of the lower case. 2. The single box tangential flow impeller water meter according to claim 1, wherein the rectifying member is in the shape of a rectangular tube having a rectangular cross section. 3. The single box tangential flow impeller type water meter according to claim 1, wherein the rectifying member has a rail shape having an H-shaped cross section. 4. The single-box tangential flow impeller water meter according to claim 1, 2 or 3, wherein the rectifying member is hooked on an inlet step of the inflow side nozzle.